CN116370692A

CN116370692A - Repair material and preparation method thereof

Info

Publication number: CN116370692A
Application number: CN202310400936.2A
Authority: CN
Inventors: 于淼
Original assignee: Qingdao Zhongke Kaier Technology Co ltd
Current assignee: Qingdao Zhongke Kaier Technology Co ltd
Priority date: 2023-04-14
Filing date: 2023-04-14
Publication date: 2023-07-04

Abstract

The invention relates to a repair material and a preparation method thereof, and belongs to the technical field of medical materials. The repair material comprises: at least a nuclear layer for providing growth factors; a shell layer allowing at least the growth factors of the core layer to pass therethrough and be released; the repair material is configured into a nanofiber with a core-shell structure based on the core layer and the shell layer in a mode of at least comprising coaxial arrangement. The repair material can overcome the problem that dressing active substances or medicine components in the prior art are influenced by wound microenvironment and are difficult to maintain higher concentration for promoting repair growth based on nanofiber materials arranged on a shell layer and active substances arranged on a core layer, so that excellent antibacterial property and tissue regeneration promoting property are realized, the problem that exogenous substances are easy to generate anaphylactic reaction can be overcome through the selection of the active substances, and the activity induction effect and healing repair efficiency on wound tissue cells are improved based on the concentration content distribution of active substance growth factors.

Description

Repair material and preparation method thereof

Technical Field

The invention relates to the technical field of medical materials, in particular to a repair material and a preparation method thereof.

Background

The skin covers the whole body and becomes an important barrier to protect the internal structures of the human body and to maintain the internal environment. However, skin is easy to suffer from wounds, skin wounds are mainly divided into acute wounds and burns and scalds at present, and under the condition that natural healing of the wounds is not performed, scars are often left, and huge psychological disorders are left for patients, and the basis for treating the wounds at present is mainly as follows: inhibit wound bacterial proliferation to reduce infection, increase active substance concentration to accelerate wound healing, inhibit scarring or reduce pain in patients based on dressing structure and composition, etc. For example, for skin burns and scalds, gauze and ointment for treating burns and scalds are generally used, but the gauze has too high porosity, too large pore diameter and poor fit with the skin, which is unfavorable for preventing invasion of external bacteria, and the high absorption capacity of the gauze can lead to dehydration of wounds and growth of rough shearing bacteria, and secondary damage can be caused when the gauze is removed. The aperture of the nanofiber membrane is smaller than that of bacteria, and the nanofiber membrane has a similar structure to an extracellular matrix, so that the nanofiber membrane is a good substitute for gauze, wherein the electrospun nanofiber membrane has a wide prospect in the application field of wound dressing due to the intrinsic characteristics such as high specific surface area, high porosity and similar structure to the extracellular matrix of skin. The ointment is an exogenous medicine, the components are relatively single, and the treatment effect is different from person to person.

The prior art has developed various novel wound dressings, such as films, hydrocolloids, hydrogels and micro/nanofibers, nanofiber materials including: chitosan, polycaprolactone (PCL), polylactic acid (PLA), etc. To enhance the ability of the dressing to prevent bacterial infection and promote wound healing, growth factors having bacteriostatic effects are often loaded in the dressing nanofibers, e.g., epsilon-polylysine epsilon-PL (Epsilon Polylysine) is a necessary nutrient for tissue repair, and epsilon-PL incorporation into the nanofibers can enhance fiber wettability and exhibit good bacteriostatic properties. The autologous platelet-rich plasma PRP (Platelet Rich Plasma) contains abundant growth factors, can promote angiogenesis and cell proliferation, and can treat different individuals and avoid anaphylactic reaction of organisms because the component ratio of each growth factor of PRP is slightly different from one individual to another. However, PRP is directly applied to the affected area, and the PRP is activated to release the growth factor, but since the growth factor is rapidly decomposed by enzymes in the wound microenvironment, it is difficult to continuously maintain a high concentration. While encapsulating PRP in nanofibers can avoid this disadvantage. Considering that PRP is water-soluble and most biodegradable materials are hydrophobic, forming PRP and fiber into core-shell structured fiber can avoid solvent miscibility problems in spinning.

In the prior art, for example, patent publication No. CN110101897A discloses a method for in-situ nursing of burn and scald skin, which comprises the steps of preparing a burn and scald nursing spinning solution, spinning the burn and scald nursing spinning solution by utilizing an in-situ electrostatic spinning device, controlling the interval distance between a nozzle and a receiving wound, and depositing nanofiber antibacterial dressing on the burn and scald affected part in situ to realize in-situ nursing of the burn and scald. According to the technical scheme, the nanofiber antibacterial dressing is deposited on a burn and scald wound in situ based on the electrostatic spinning equipment, but the antibacterial dressing does not contact the wound to cause a gap or interval between the surface of the wound and the dressing, so that the nanofiber antibacterial dressing cannot effectively transfer the drug active ingredients to the surface of the wound.

The patent with publication number CN107137748B discloses a core-shell electrostatic spinning chitosan nanofiber wound dressing and a preparation method thereof, wherein nanofibers of the dressing for repairing an affected part are configured into a core-shell structure, chitosan, sodium carboxymethyl cellulose and polyoxyethylene are added into an aqueous solution containing a small amount of acetic acid and ethanol to obtain an outer layer solution, the polyoxyethylene is added into the aqueous solution to obtain a solution A, a lithium alginate soil solution is prepared in addition, a small amount of sodium pyrophosphate is added to obtain a solution B, the solution A and the solution B are mixed to obtain an inner layer solution, and the outer layer solution and the inner layer solution are prepared into the core-shell nanofiber dressing by adopting a coaxial electrostatic spinning method. The patent with publication number CN110464866A discloses a core-shell drug-loaded nanofiber dressing and a preparation method thereof, wherein the nanofiber of the dressing also adopts a core-shell structure, a core layer consists of honey and polyvinyl alcohol, and a shell layer consists of epsilon-polylysine and polycaprolactone. According to the technical scheme, the core-shell structure is prepared based on an electrostatic spinning technology, and different substances of the nanofiber dressing are respectively arranged on the core layer and the shell layer, so that the shell layer is prepared from a hydrophobic polymer with proper mechanical properties and biocompatibility and a performance improving component, the core layer is prepared from a material or an active substance for controlling the physicochemical properties of the nanofiber, but the active substance is an exogenous component, so that organism allergic reaction possibly generated in the using process cannot be overcome, and negative effects possibly can be caused based on the specific conditions of patients; and exogenous active substances placed in the nuclear layer cannot be pertinently arranged according to the internal environmental difference of the human body, so that the exogenous active substances cannot guarantee the induction of the wound repair activity and the efficiency improvement effect.

Patent publication No. CN108434529A discloses an in-situ self-bionic repair material for fat liquefaction wounds, and a preparation method and application thereof. The in-situ self-bionic repair material for the fat liquefaction wound comprises a self functional layer, a biological functional layer and a surface isolation layer; wherein the autologous functional layer is PRP prepared after collecting whole blood of a patient; the biological functional layer is one or more of chitosan fiber, alginic acid fiber, collagen fiber, oxidized cellulose fiber, gelatin fiber and the like, and is a fiber layer structure, and the 3-dimensional net structure can be used for infiltration and fixation of components in the self functional layer; the surface isolation layer is a polyurethane semipermeable membrane. But the autologous function layer directly arranged on the wound can lead the autologous platelet-rich plasma to be activated by directly contacting the wound microenvironment, so that active sites for promoting repair and growth are released, but active substances can be rapidly decomposed by enzymes of the wound microenvironment, and high concentration is difficult to continuously maintain.

Based on the analysis, in the nanofiber dressing for repairing skin wounds in the prior art, the arrangement of the dressing based on the direct contact of active substances or medicinal components with the wound surface easily causes the active substances or medicinal components to be influenced by the microenvironment of the wound surface, so that the higher concentration for promoting the repair growth is difficult to maintain; the dressing is based on a core-shell structure, exogenous active substances or drug components are placed in the inner layer, the exogenous active substances cannot overcome the allergic reaction of organisms possibly generated in the using process, and the release strategy and release rate of the active substances or drug components cannot be regulated by a single shell structure so as to ensure the applicability and pertinence of the induction and the efficiency improvement of the wound repair activity.

Furthermore, there are differences in one aspect due to understanding to those skilled in the art; on the other hand, as the inventors studied numerous documents and patents while the present invention was made, the text is not limited to details and contents of all that are listed, but it is by no means the present invention does not have these prior art features, the present invention has all the prior art features, and the applicant remains in the background art to which the rights of the related prior art are added.

Disclosure of Invention

In view of at least some of the shortcomings set forth in the prior art, the present invention provides a repair material comprising: and a core layer for providing at least a growth factor, and a shell layer for allowing at least the growth factor of the core layer to pass through and release, wherein the repair material is configured into a nanofiber with a core-shell structure based on the core layer and the shell layer in a manner of at least including a coaxial arrangement. The shell layer comprises at least a first component for forming a shell body and a second component for modifying the first component; the core layer includes at least a third component for releasing growth factors. The first component may be configured as polycaprolactone, the second component may be configured as epsilon-polylysine, and the third component may be configured as autologous platelet rich plasma.

The application adopts polycaprolactone and other degradable organic polymers as the spinning main material, controls the fiber morphology, ensures the fiber structure, can form an effective barrier compared with the existing repair dressing or gel, protects the wound surface of the tissue, and can ensure that the active ingredients of the medicine are not influenced and can control the release of the active ingredients. Polycaprolactone also has excellent biological performance and wire forming performance, and the material is nontoxic, harmless and nonirritating. The added epsilon-polylysine is used for adjusting the wettability and antibacterial property of the polycaprolactone, so that the strong hydrophobic property of the polycaprolactone is compensated, the electrostatic spinning nanofiber membrane can absorb redundant tissue exudates of an affected part, the relative moist environment of the affected part is ensured, and the adhesion effect of a repair material and tissue cells is obviously enhanced.

The dressing aims at solving the problem that the arrangement of the dressing based on the active substance or the medicine component in direct contact with the wound surface in the prior art easily causes that the active substance or the medicine component is influenced by the microenvironment of the wound surface, so that the higher concentration for promoting the repair growth is difficult to maintain. The repair material suitable for the wound in the application is the nanofiber with the core-shell structure, and the nanofiber is based on the functional material that the core-shell structure corresponds to in the core layer and the shell layer respectively, so that the repair material can remarkably improve the repair capability and the repair efficiency for the wound. In particular, in the prior art, a plurality of polymer nanofiber materials are proposed for dressing suitable for wounds to replace the traditional gauze, and in order to improve the repair efficiency of the nanofiber materials, the nanofiber materials are also often combined with active substances capable of releasing growth factors, but under the condition that the active substances directly contact with the microenvironment of the surfaces of the wounds, the active substances or the growth factors are decomposed by wound enzymes and cannot keep high concentration for promoting wound recovery. The repair material can place an active substance for providing growth factors in a core layer based on a core-shell structure of the nanofiber, and the nanofiber material serving as a material body is arranged in a shell layer, wherein the fiber pore diameter of the shell layer is smaller than that of bacteria, so that the external environment of a wound can be effectively isolated and the invasion of bacteria can be prevented, the fiber pore diameter of the shell layer can allow the growth factors continuously released by the core layer to pass through and gather on the surface of the wound, and the environment of the wound surface can maintain the growth factors with higher concentration so as to ensure the induction efficiency for wound repair.

In order to solve the problem that exogenous active substances cannot overcome the allergic reaction of organisms possibly generated in the using process and improve the applicability of the repairing material to wound repair. The repairing material is characterized in that a second component for improving physical properties is added to a first component serving as a main body of the nanofiber shell, so that the shell of the nanofiber can obtain physical properties which are more suitable for wound repair based on the second component, and the physical properties can comprise bacteriostasis, hydrophilicity, fiber pore diameter, fiber strength and the like. For example, the first component and the second component are respectively configured as polycaprolactone and epsilon-polylysine, and epsilon-polylysine can effectively improve wettability and bacteriostasis of the polycaprolactone, so that a shell layer comprising the polycaprolactone and epsilon-polylysine can be convenient for cell attachment and infiltration, is favorable for cell adhesion and proliferation, and has good biocompatibility. The active substance used for releasing the growth factors in the application can be autologous PRP, which not only contains rich growth factors and can promote angiogenesis and cell proliferation, but also can realize treatment according to individuals and avoid anaphylactic reaction of organisms because of autogenesis and the composition ratio of each growth factor of PRP is slightly different from person to person. Considering that the self-derived PRP is water-soluble and most biodegradable materials are hydrophobic, the formation of nanofibers into a core-shell structure can also avoid solvent miscibility problems in spinning.

And the repair material can also control the speed of releasing growth factors from the core layer to the wound surface and the action effect of the shell layer and the wound surface based on the adjustment of the preparation parameters of the core layer and the shell layer, so that the repair material positioned at different spatial positions of the wound can set a targeted release strategy and release rate based on different action stages to ensure the applicability of the induction and the efficiency improvement of wound repair activity. Namely, the polycaprolactone and epsilon-polylysine form a medicine diffusion slow release carrier aiming at autologous platelet-rich plasma, so that the abrupt release of the medicine is reduced, the medicine carrying is uniform, the release is controllable, the sustained effect of the medicine on the wound is ensured, and the healing process is accelerated.

Preferably, the nanofibers have a diameter of 0.2 to 1.2 μm, preferably 0.4 to 1.0 μm, more preferably 0.6 to 0.9 μm.

Preferably, the nanofiber core layer has a diameter of 0.1 to 1.0. Mu.m, preferably 0.3 to 0.8. Mu.m, more preferably 0.4 to 0.7. Mu.m.

Preferably, the shell thickness of the nanofibers is 0.01 to 0.5 μm, preferably 0.1 to 0.3 μm.

Preferably, the shell layer of the nanofiber is configured as a porous structure, and the fiber pore diameter of the shell layer is 4-10 nm, preferably 6-8nm.

Preferably, the water contact angle of the shell layer of the nanofiber is 40 to 80 degrees, preferably 50 to 70 degrees.

The microstructure of the repair material nanofiber is observed through experiments, the overall size, the nuclear layer size and the shell layer size of the nanofiber are optimized, so that the nanofiber has good mechanical properties, the morphology of the nanofiber and an extracellular matrix have similar structures, structural support and mechanical force can be provided for tissues, and a nanofiber membrane prepared from the nanofiber and a nanofiber three-dimensional structure can be ensured to have excellent mechanical properties and physicochemical properties. The shell layer of the nanofiber is configured into a porous structure, and the fiber pore diameter of the shell layer blocks bacteria from entering and allows active substances and growth factors to be continuously and slowly released from the core layer, so that the active substances and growth factors on the surface of a wound are ensured to have higher concentration for promoting tissue healing.

The invention also provides a preparation method of the repair material, which comprises the following steps:

a. mixing polycaprolactone and epsilon-polylysine with medical acetone to prepare a shell solution for preparing a nanofiber shell;

b. dissolving autologous platelet rich plasma in a polyvinyl alcohol solution to prepare a core layer solution for preparing a nanofiber core layer;

c. preparing the shell layer solution and the core layer solution into nano fibers with core-shell structures based on coaxial electrostatic spinning, wherein the nano fibers are configured into a repairing material with at least one of one-dimensional structures to three-dimensional structures at least based on an in-situ deposition mode.

The electrostatic spinning is one of the simplest and most efficient methods for preparing the nanofiber at present, and compared with the traditional nanomaterial preparation technology, the electrostatic spinning has the advantages of simple processing device, wide raw material source, low spinning cost, large-scale preparation and the like. The micro-nano fiber prepared by adopting the electrostatic spinning technology has the excellent characteristics of high specific surface area, larger length/diameter ratio, unique physical chemistry and the like, and has great application potential in the fields of biological tissue engineering, wound dressing, filtration protection, medicine slow release, flexible devices and the like. The nanofiber prepared by the electrostatic spinning technology has good biocompatibility, mechanical property and degradability, and is widely applied to biomedicine. The form of the nanofiber has a similar structure with the extracellular matrix, can provide structural support and mechanical force for tissues, and provides a certain space for cell attachment and infiltration. The repair material is prepared based on the coaxial electrostatic spinning technology, so that the characteristics of the repair material can obtain corresponding functional structures, and the repair material has important significance for treating burns and scalds.

Preferably, in the step a, the mass ratio of polycaprolactone, epsilon-polylysine and medical acetone is (3-50): (1-5): (10 to 300), preferably (5 to 30): (1-3): (20-200); the mixing is carried out by adopting a stirrer, and the stirring time is 10-15 hours.

Preferably, in step b, the mass concentration of the polyvinyl alcohol solution is 1-30%, preferably 3-15%; the mass ratio of the polyvinyl alcohol solution to the autologous platelet-rich plasma is (1-5): (1 to 20), preferably (1 to 3): (1-10).

Preferably, in step c, the spinning voltage of the coaxial electrostatic spinning is 8-25 kv, preferably 10-20 kv; the flow rate of the shell layer solution and the flow rate of the core layer solution of the coaxial electrostatic spinning are respectively 0.3-0.8 ml/h and 0.8-2.0 ml/h, preferably 0.4-0.6 ml/h and 1.0-1.5 ml/h; the distance between the coaxial electrostatic spinning needle head and the receiving electrode is 8-25 cm, preferably 10-18 cm; the diameter of the spinning nozzle for coaxial electrostatic spinning is 0.2-1.0 mm, preferably 0.3-0.6 mm.

Drawings

FIG. 1 is a microstructure of a prosthetic material according to a preferred embodiment of the invention;

FIG. 2 is a graph of repair material performance parameters for a preferred embodiment of the present invention;

FIG. 3 is a comparative graph of antimicrobial activity of a prosthetic material according to a preferred embodiment of the present invention;

FIG. 4 is a comparative graph of cell proliferation experiments of a prosthetic material according to a preferred embodiment of the present invention;

FIG. 5 is a diagram showing the experimental analysis of cell proliferation of a prosthetic material according to a preferred embodiment of the present invention;

FIG. 6 is a comparative graph of a wound of a prosthetic material of a preferred embodiment of the present invention in a living animal experiment;

FIG. 7 is a comparative chart of tissue of a repair material histological experiment HE stained wound in accordance with a preferred embodiment of the present invention;

fig. 8 is a graph of tissue comparison of Masson stained wounds for repair material tissue experiments in accordance with a preferred embodiment of the present invention.

Detailed Description

The present invention will be described in detail with reference to the accompanying drawings.

The application provides a repair material, in particular relates to a repair material based on nanofibers, and particularly relates to an in-situ self-bionic repair material which is suitable for wound repair treatment. The skin covers the whole body to become an important barrier for protecting the internal structure of the human body and maintaining the internal environment, and can protect the internal tissues of the human body from bacteria. However, skin is vulnerable to wounds, skin wounds are mainly classified into acute wounds and burns and scalds at present, and wounds caused by surgical operations, wounds, superficial burns and the like are all required to be wrapped by dressing to prevent bacterial invasion, and the wound inflammation is avoided so as to accelerate the wound healing process. In order to improve the antibacterial capability of the dressing and the capability of loading active substances and drug components to improve the recovery rate and recovery quality of wounds, nanofiber membranes for wound dressings are proposed in the prior art, and the intrinsic characteristics of the nanofiber membranes comprise high specific surface area, high porosity and structures similar to skin extracellular matrixes, so that the nanofiber membranes can isolate bacteria based on structural characteristics and can be used for loading the active substances and the drug components, and the nanofiber membranes have wide prospects in the application field of wound dressings. The repairing material and the preparation process and the performance experiment verification process of the repairing material are specifically described below.

Example 1

Regarding the preparation method of the repair material, in this embodiment, a coaxial electrostatic spinning method is used to prepare the repair material composed of the core-shell structure nanofibers, and the coaxial electrostatic spinning method is used to configure the shell solution and the core layer solution of the shell material and the core layer material according to the core-shell structure of the repair material nanofibers. The main active substances of the shell solution are polycaprolactone and epsilon-polylysine, and medical acetone is used as a solvent and the solution is uniformly mixed; the main active substance of the nuclear layer solution is autologous platelet rich plasma, and polyvinyl alcohol solution is used as solvent. Preparing nanofiber with core-shell structure by using coaxial electrostatic spinning method, processing nanofiber into repairing material, adding nanofiberThe repair material is processed in such a way that the repair material is formed to include at least one of a one-dimensional structure to a three-dimensional structure based on nanofiber parameter settings. For example, a one-dimensional structure comprises different nanofiber segments in one dimension, a two-dimensional structure comprises different nanofiber segments in a two-dimensional plane, and a three-dimensional structure comprises different nanofiber segments in a three-dimensional volume. Specifically, 2g of Polycaprolactone (PCL) and 0.4g of epsilon-polylysine (epsilon-PL) were dissolved in 10g of medical acetone and stirred in a magnetic stirrer for 12 hours as a coaxially electrospun shell solution; 0.5g of polyvinyl alcohol was dissolved in 10g of water to give a 5% polyvinyl alcohol solution (PVA) which was treated with CaCl ₂ The autologous platelet-rich plasma (autologous PRP, hereinafter abbreviated as PRP) activated and passing through the blood routine test is dissolved in 5% polyvinyl alcohol solution (PVA), and the mass ratio of the autologous platelet-rich plasma (autologous PRP, hereinafter abbreviated as PRP) to the polyvinyl alcohol solution (PVA) is 2:1, as a coaxially electrospun core layer solution.

In order to obtain a targeted comparison experiment result, the embodiment is provided with a plurality of groups of nanofiber repair materials based on different action substances of polycaprolactone, epsilon-polylysine, autologous platelet-rich plasma and different coaxial electrostatic spinning schemes, and the repair materials are prepared into nanofiber membranes based on nanofibers. The coaxial electrostatic spinning scheme comprises traditional electrostatic spinning and in-situ electrostatic spinning, wherein the traditional electrostatic spinning is to process a nanofiber membrane prepared based on an electrostatic spinning device and then cover the nanofiber membrane on a wound to form a nanofiber membrane similar to a gauze cover; the in-situ electrostatic spinning is based on the coaxial electrostatic spinning device to directly deposit the prepared nanofiber serving as a repairing material on a wound in situ and directly form a nanofiber membrane fully covering the wound.

Specifically, three groups of nanofiber membranes of PCL, PCL+epsilon-PL and PCL+PRP+epsilon-PL are prepared by using traditional electrostatic spinning, the electrostatic spinning voltage of the three groups is 17.6KV, and the flow rates of an electrostatic spinning core layer solution and a shell layer solution are respectively 0.5ml/h and 1.2ml/h. The distance between the electrostatic spinning needle and the receiving electrode is about 15cm, and all spinning processes are carried out under the conditions of 25 ℃ and 50% humidity. In-situ electrostatic spinning is used for preparing an In-situ PCL+PRP+epsilon-PL (In-situ PCL+PRP+epsilon-PL) group nanofiber membrane based on the preparation method, and In the step a, the mass ratio of polycaprolactone, epsilon-polylysine and medical acetone is 5:1:25, mixing by a stirrer for 12 hours. In the step b, the mass concentration of the polyvinyl alcohol solution is 5%; the mass ratio of the polyvinyl alcohol solution to the self-derived PRP is 1:2. in the step c, the spinning voltage of coaxial electrostatic spinning is 10kv; the flow rate of the shell layer solution and the flow rate of the core layer solution of the coaxial electrostatic spinning are respectively 0.5ml/h and 1.2ml/h; the distance between the needle head and the receiving electrode of the coaxial electrostatic spinning is 10cm; the diameter of the spinning nozzle for coaxial electrostatic spinning is 0.4mm.

The four groups of repair materials such as the PCL, PCL+epsilon-PL, PCL+PRP+epsilon-PL group nanofiber membrane and In-situ PCL+PRP+epsilon-PL group nanofiber membrane can obtain a targeted comparison analysis result based on experiments so as to clearly act on substances and the action contribution of an electrostatic spinning scheme to the repair materials.

Regarding the microstructure of the nanofiber membrane prepared by the In-situ PCL+PRP+ε -PL group, FIG. 1a is an SEM image of the nanofibers of the present application, having diameters ranging from 0.2 to 1.2 μm, diameters mostly between 0.4 and 1.0 μm, median average between 0.6 and 0.9 μm, and average diameters of about 0.7 μm. Fig. 1b is a TEM image of such a nanofiber, from which it can be seen that the nanofiber is in a coaxial structure, i.e. the nanofiber of the repair material of the present application has a coaxial core-shell structure. And further dyeing the nanofiber, and respectively marking solutions corresponding to the nuclear layer and the shell layer with calcein and rhodamine B. FIGS. 1c-e show green nuclear layer and red shell layer by excitation at 495nm wavelength under confocal microscope, confirming the core-shell structure of the nanofiber with PRP concentrated in the nuclear layer. The nanofiber core diameter is 0.1 to 1.0 μm, preferably 0.3 to 0.8 μm, more preferably 0.4 to 0.7 μm, corresponding to the size ratio of the nanofiber core diameter to the nanofiber diameter; and the thickness of the nanofiber shell layer is 0.01 to 0.5 μm, preferably 0.1 to 0.3 μm. I.e., the core layer in the nanofiber is positioned on the inner side and the shell layer is coaxially wrapped around the core layer on the outer side to form the nanofiber with a coaxial core-shell structure. The core layer is used for providing the growth factors, the shell layer allows the growth factors to pass through and release to act on wound tissues, the first component serving as a shell body in the shell layer is polycaprolactone, the second component serving as a first component in the shell layer is epsilon-PL, and the effect of epsilon-PL on PCL at least comprises wettability improvement and antibacterial capacity improvement. The third component of the nuclear layer is PRP, in the traditional single-needle electrostatic spinning process, the PRP can be directly mixed and contacted with an organic solvent to cause the inactivation and denaturation of biological proteins and cytokines in the PRP, and the core-shell structure is designed to ensure that the PRP adopts aqueous solvent spinning in the nanofiber and the fiber outer shell layer adopts the organic solvent spinning mode to well protect the activity of the biological proteins and the cytokines of the PRP. In addition, compared with the traditional single-needle electrostatic spinning, the coaxial electrostatic spinning method for preparing the core-shell structure can slow down the release speed of doping substances in the fiber, such as growth factors, medicines and the like, based on the porous structure of the nanofiber shell fiber, and the slow and continuous release can generally meet the requirement of tissue repair on the concentration of the medicines.

FIG. 2a is a FTIR spectrum of an In-situ PCL+PRP+ε -PL nanofiber membrane with nanofibers (green line) at 1725cm ^-1 A carboxyl stretching vibration peak with ester group at 1245cm ^-1 There are stretching peaks of-C-O-C-which originate from PCL (blue line) and which are at the same time at 1640cm ^-1 And 1520cm ^-1 The vibration peak at this point is from ε -PL (red line), which demonstrates that the bulk of the nanofiber consists of PCL and ε -PL. Because the PRP rich growth factors are distributed in the nanofiber nuclear layer, in order to enable the drugs and active substances in the nanofiber nuclear layer to be released more easily, the nanofiber should have a porous structure and have good wettability, so that the drugs and active substances can be timely diffused after the tissue fluid infiltrates the nanofiber. First, the N2 adsorption-desorption curve of the nanofibers was first tested, and it can be seen from fig. 2b that a distinct hysteresis loop appears between the adsorption and desorption curves, indicating that the nanofibers are porous with a fiber pore size of 4 to 10nm, preferably 6 to 8nm. Second, when the contact angle of water was measured, it can be seen from FIG. 2c that the PCL group had a water contact angle of about 109℃and was a hydrophobic material, and that the water contact angle was changed from 109℃to 62℃after addition of ε -PL About, the water contact angle can be controlled to 40 to 80 degrees, preferably 50 to 70 degrees, based on the ratio of the active ingredients, successfully changing the hydrophilicity of the nanofiber membrane. The nanofiber membrane has good hydrophilicity, can form a moist microenvironment on the surface of a wound, effectively absorbs exudates at the wound, and is beneficial to wound repair. Third, the release profile of several growth factors that have a positive effect on burns and scalds was evaluated. FIG. 2d shows that PDGF-BB is released more rapidly in tissue fluid than TGF-beta and VEGF, probably due to the bias of PDGF-BB towards water solubility and the bias of TGF-beta and VEGF towards lipid solubility. Furthermore, it can be seen that the PDGF-BB content is higher than the TGF- β and VEGF, which is also why the use of autologous PRP in the present application is considered to be due to the fact that the three growth factors are different for different people, whereas the specific content ratio of autologous growth factors is the optimal content ratio for this person and is effective in reducing the excretion variability.

Based on the experimental results of microstructure and spectrum analysis, the nanofiber prepared based on the in-situ coaxial electrostatic spinning method has a core-shell structure, the first component of the shell layer is polycaprolactone, the polycaprolactone can form a nanofiber shell layer with a fiber aperture based on electrostatic spinning, when the nanofiber prepared from the polycaprolactone is covered on a wound, the size of the fiber aperture is smaller than the size of bacteria, so that invasion of bacteria into the wound is blocked, but the polycaprolactone is a hydrophobic material, so that wound tissues are not easy to adhere. The second component of the shell layer is epsilon-polylysine, which is used for modifying polycaprolactone and at least comprises the improvement of the antibacterial property and wettability of the polycaprolactone, and as shown in the experimental data, the improvement of the wettability is shown in epsilon-polylysine, so that the water contact angle of the polycaprolactone can be greatly reduced, the wound tissue can be effectively attached, and the cell adhesion and proliferation are facilitated. The preparation parameters in the preparation method are optimized implementation parameters and preferred implementation modes for preparing the repair material nanofiber based on experimental design debugging, the selection of the preparation parameters determines the ranges of material parameters such as nanofiber diameter, nuclear layer diameter, shell layer thickness, shell layer fiber aperture, water contact angle and the like, and the ranges of the material parameters determine the antibacterial property, wettability and growth factor release and distribution conditions of the repair material, namely, the realization of the technical effect of the repair material is closely related to the material parameters and the preparation parameters in the application, so that the nanofiber repair material with the nuclear shell structure prepared based on the preparation method can be suitable for wound repair and has excellent antibacterial healing promotion performance.

Example 2

Comparative analysis of antimicrobial properties of repair materials: for comparison test, three groups of nanofiber membranes of PCL, PCL+epsilon-PL, PCL+PRP+epsilon-PL and the antibacterial performance of the nanofiber membrane of In-situ PCL+PRP+epsilon-PL were prepared by using the traditional electrostatic spinning equipment. The antibacterial effect was evaluated by disc agar diffusion. First, about 1X 10 will be under sterile conditions ⁸ The E.coli and Staphylococcus aureus suspensions of individual cells were inoculated onto a ready-to-use nutrient agar medium (9 cm. Times.9 cm), several groups of nanofiber membranes for experiments were cut into nanofiber mats having a radius of 1cm, and then the nanofiber mats were placed in the center of the bacteria-coated 9 cm. Times.9 cm agar medium, and cultured in a constant temperature and pressure oven at 30℃for 18 hours. Because the wound surface of the burn and scald is easy to be infected by bacteria, if the nanofiber can kill gram-negative bacteria and gram-positive bacteria, the burn and scald treatment can be facilitated. Thus, in vitro antimicrobial evaluation was performed by disc agar diffusion. The control group in fig. 3a is untreated e.coli and s. No antibacterial ring appeared after covering the PCL fiber, indicating that PCL had no killing effect on bacteria. The other three groups, PCL+ε -PL, PCL+PRP+ε -PL, in-site PCL+PRP+ε -PL, all present very distinct antimicrobial loops and are of substantially the same radius, indicating that the antimicrobial effect should be derived from ε -PL. epsilon-PL can interfere the normal synthesis of the cell wall of the microorganism, so that the permeation resistance and pressure resistance of the thalli are reduced, and the thalli are deformed, ruptured and killed. From further SEM images of E.coli and Staphylococcus aureus (FIGS. 3b, d), it was confirmed that untreated E.coli had a rod-like structure, a smooth surface and a plump morphology without cell breakage (FIG. 3 b). After being treated by PCL+PRP+epsilon-PL nanofiber, the cell membrane of the thalli is shrunken and has no satiety cell membrane A constriction appears on the surface (fig. 3 c). Staphylococcus aureus and escherichia coli showed similar results (fig. 3d, e). This can confirm that after addition of epsilon-PL, it can disrupt the cell membrane structure of microorganisms, leading to bacterial lysis and thus achieving bactericidal effect.

Comparative analysis of cytotoxicity with respect to repair material: since the PRP-containing nanofiber membrane is finally used in the human body, no toxicity is required. Thus, fibroblasts were seeded onto different 4-group and control slides, and their cellular responses were detected. After alcohol sterilization and ultraviolet irradiation of the nanofiber membrane, the metabolic activity of the cells was measured by CCK-8. All experimental steps need to be performed in a sterile ultra clean bench. The experiment was divided into the above 5 groups, including the conventional electrospinning group PCL, PCL+ε -PL group, PCL+PRP+ε -PL group and In-situ PCL+ε -PL+PRP group. Each group had 4 duplicate wells. The above 5 nanofiber membranes and control empty slides were placed in 24 well plates, phosphate Buffered Saline (PBS) was washed once, serum-free medium was washed three times, 100. Mu.l of complete medium was added, and the mixture was placed in a 37℃incubator. Next, fibroblasts with a confluence of 90% were taken out of the incubator, rinsed 3 times with phosphate buffer solution PBS, added with 200 μl of pancreatin, put into the incubator to digest the cells, taken out after 3 minutes and stopped with 1ml of complete medium (DMEM high sugar hyclone,10% fetal bovine serum, 1% diabody), repeatedly blown off the cells, put into 1.5ml of EP tube, and centrifuged (900 rmp,5 min). The supernatant was discarded and 1ml of complete medium was used to resuspend the cells. Mu.l of the cell suspension was extracted and counted to give a cell number of 80X 10 ⁴ And each ml. The number of cells planted per well was about 10 ⁵ After preparing the desired cell suspension at a volume of each ml, 100. Mu.l of the cell suspension was pipetted into each air by a pipette. 2 hours, medium was supplemented to 700. Mu.l. Cell proliferation numbers were measured for 4 hours, 12 hours, 1, 3, and 5 days, respectively. After removal of the old medium, phosphate Buffered Saline (PBS) was rinsed once and complete medium (400. Mu.l per well) containing 10% CCK-8 reagent was added, taking care that the addition was protected from light. At 37℃at 5% CO ₂ Incubated for 2h in a humidified atmosphere. Adding 100 μl of liquid in 2-well plate into 96-well plate, each group of 3 multiple wells, packaging with tinfoil, and performing enzyme labelingThe absorbance at 450nm was monitored.

For further in vivo applications, PRP-containing nanofibers are required to be non-cytotoxic. Thus, human fibroblasts were seeded on the nanofiber membrane to evaluate their cellular response. Polystyrene Tissue Culture Plates (TCP) were incubated with fibroblasts on the same day as the control group. The attachment and morphology of human fibroblasts is determined by double-labeled fluorescent staining of actin cytoskeleton and nuclei. FIGS. 4a-e show cells on different sets of nanofiber membranes. FIG. 5 shows proliferation of human foreskin fibroblasts (HSFs) cultured on control, PCL, PCL+ε -PL, PCL+ε -PL+PRP, in-situ PCL+ε -PL+PRP for 1, 3, 5 days, respectively. The Control group was a positive Control group, and each group was on an ascending trend from day 1 to day 5. The PCL group showed more pronounced proliferation than the control group, which suggests that pure PCL-spun fibers are inherently better biocompatible. After the HSFs are cultured on different samples for 1 day, the proliferation effect of the HSFs on the different samples is not obvious, and after the culture is carried out on the 3 rd day, the proliferation of the HSFs on PCL+epsilon-PL is better than that of the HSFs on PCL. The epsilon-PL was shown to be an antibacterial substance, but it was not toxic to cells. After HSFs were cultured on different samples for 5 days, the proliferation of HSFs on PCL+ε -PL+PRP and In-situ PCL+ε -PL+PRP was significantly (P < 0.01) better than on PCL and PCL+ε -PL groups. These experimental results show that PRP promotes proliferation of HSFs, and that these nanofibers are non-toxic and have no side effects on cells.

Comparative analysis of prosthetic material in vivo experiments: for testing the curative effect, 40 SD rats are randomly divided into 5 groups, PCL, PCL+epsilon-PL, PCL+epsilon-PL+PRP fiber scaffolds with proper shapes are respectively sheared according to the shape of wound surfaces of skin scalds, the In-situ PCL+PRP+epsilon-PL groups directly cover PCL+PRP+epsilon-PL nanofiber membranes on the wound surfaces by using a handheld electrostatic spinning device on the skin wound surfaces of the backs of the rats, and all the wound surfaces of the groups are covered by gauze and sewn and fixed by silk threads, so that the mutual interference among animals is avoided, and single cage feeding is performed. After the wound surface of the burn and scald rat is covered by a bracket or naturally healed, photographing for 1, 3, 5, 7, 9, 14 and 21 days and observing the healing condition. Wound recovery from deep second degree scalds was assessed with SD rats and recorded by photographing on day 3, day 5, day 7, day 9, day 11, day 14, and day 21, respectively. Secondary burns and scalds affect the upper dermis and deep dermis, which is white or yellow, foaming and moist in appearance. As shown in FIG. 6a, after 3 days of scalding, the swelling of the wound surface and the red swelling around the wound are most obvious, and the PCL is used for the second time, because the PCL nanofiber membrane can prevent bacteria in the air from infecting the wound, and has a protective effect on the wound. On day 5 after scalding, the recovery effect of the PCL+epsilon-PL group is obviously better compared with that of the PCL group, which is attributed to the epsilon-PL having antibacterial capability, and bacterial infection is reduced, so that the recovery of wounds is facilitated. On day 14, the PCL+ε -PL group still seen significant crusting, in sharp contrast to the PCL+ε -PL+PRP group, which had completely disappeared and almost completely recovered on day 21. This demonstrates that the various growth factors contained in PRP greatly aid wound healing and effectively promote wound repair.

The nanofiber membrane obtained by traditional electrospinning is subjected to two processes of spinning and using, and the nanofiber membrane is cut and then covered on the surface of a wound. However, the nanofiber membrane obtained by this conventional method is inferior in the degree of adhesion to a wound, similar to the use of gauze. Fig. 6c shows a conventional nanofiber membrane coated on the skin, and the adhesion between the nanofiber membrane and the skin was tested to be 0.02N. In contrast, the hand-held device based on in-situ spinning directly deposited the fibers onto the skin, tested for a 0.18N adhesion between the nanofiber membrane and the skin. Better fit will positively affect repair. Therefore, based on PCL+epsilon-PL+PRP group, the difference of the traditional method and the in-situ spinning method on burn and scald repair is further compared. As can be seen from FIG. 6b, the In-situ PCL+PRP+ε -PL group exhibited a faster recovery rate than the conventional spin pack. This is probably due to the better fit, which can effectively prevent external bacteria from invading the wound from the fit gap of the nanofiber membrane-skin interface, thereby accelerating burn and scald recovery. This demonstrates that the use of in situ deposition can further enhance the effectiveness of the dressing containing the antimicrobial and growth factors, and better fit not only reduces gaps to reduce the probability of bacterial infection, but also reduces the distance from the skin, facilitating the timely and effective transfer of growth factors to the wound, while enhancing the efficacy of the antimicrobial and growth factors.

Comparative analysis of tissue reaction with respect to repair material: histological analysis is carried out, new tissues are frozen and sectioned, and then HE staining, masson staining and other methods are used for observing the healing process of the skin wound surface of the rat (the conditions of wound inflammatory reaction, fibroblast proliferation, collagen secretion and classification, epidermal layer differentiation and the like). Scalded tissues of SD rats on day 1, day 7, day 14, and day 21 were fixed on slides for hematoxylin-Yin Gong (H & E) and Masson staining, and HE and Masson staining were used to assess the number of bacteria around the wound and wound recovery progress, respectively. Histopathological changes of the wound were observed under a microscope.

Wound repair of burns and scalds is a complex process, and in order to analyze the relationship between wound infection and recovery from a microscopic point of view, HE staining (fig. 7) is performed on a sample to evaluate the state of wound repair. On days 3 to 7 of the burn, the control group was seen to have many lymphocytes and the PCL group was relatively few. This suggests that the PCL group has fewer lymphocytes because the coverage of the nanofiber membrane protects the wound from bacterial invasion. On day 7, the PCL+ε -PL group exhibited fewer lymphocytes than the PCL group. This is because epsilon-PL has antibacterial properties and can lyse bacteria and thereby reduce bacteria at wounds. On day 14, the PCL+ε -PL+PRP group showed significantly more blood vessels than the PCL+ε -PL group, because PRP contained various growth factors, and when PRP encountered interstitial fluid, ca2+ in the interstitial fluid activated PRP to release the growth factors, accelerating tissue repair and regeneration. On day 21, the In-situ PCL+epsilon-PL+PRP group exhibited more blood vessels and fewer neutrophils than the PCL+epsilon-PL+PRP group, because the fibers deposited on the wound In situ had better conformability, could effectively prevent external bacteria from invading the wound from the lamination gap of the nanofiber membrane-skin interface to promote antibacterial activity, and reduced the gap distance from the skin, thereby facilitating the growth factors to be effectively transferred to the wound as well as promoting the repair efficacy of the growth factors to the tissue. This demonstrates from a microscopic point of view that the use of in situ deposition can further enhance the effectiveness of the dressing containing the antimicrobial and growth factors. Collagen deposition in wound tissue was further observed by parkinson's trichromatography (fig. 8). It can be seen that on day 3, only a small amount of collagen fibers appeared in all groups. On day 7, collagen fibers were irregularly arranged for all wound groups. On day 14, the PCL+ε -PL group had less blue collagen fibers and granulation tissue, while the PCL+ε -PL+PRP group and the In-situ PCL+PRP+ε -PL group were relatively dense In collagen fibers. On day 21, the In-site PCL+ε -PL+PRP group first formed a complete layer of epithelial tissue on the wound tissue surface, indicating that tissue repair has been completed. The results of these experiments indicate that it is far from sufficient to rely on antimicrobial alone for the purpose of wound healing. Wound repair not only requires bactericidal action to ablate bacteria and reduce inflammation, but also promotes wound healing through the coaction of various growth factors, and the in-situ deposition method can further improve the effect of the dressing containing the antibacterial and growth factors.

Based on the performance comparison experiments of the antibacterial property, cytotoxicity, in-vivo experiments, tissue examination and the like, the technical effect of the repair material is closely related to the action substances such as epsilon-polylysine, autologous platelet-rich plasma and the like and material parameters. For example, for epsilon-polylysine, epsilon-polylysine not only improves the wettability and improves the antibacterial performance of the repair material shell layer polycaprolactone, but also has significance for the release speed and distribution of growth factors in autologous platelet-rich plasma due to the shell layer of the repair material formed by epsilon-polylysine and polycaprolactone, the autologous platelet-rich plasma positioned in the nuclear layer is coaxially wrapped by the repair material shell layer formed by epsilon-polylysine and polycaprolactone and has fiber holes allowing growth factors in the autologous platelet-rich plasma to pass through, wound tissue cells adhere and proliferate on the outer surface of the shell layer, and the growth factors move from the inner side of the shell layer to the outer side of the shell layer to keep the growth factors near the tissue cells at a higher concentration, so that the shell layer serves as an organic degradable barrier for isolating the wound environment and the autologous platelet-rich plasma, and the autologous platelet-rich plasma can be prevented from being decomposed by enzymes on the wound surface and incapable of continuously releasing the growth factors. The fiber pore size of the shell layer is matched with the growth factor size, the degradation speed of the shell layer is also adaptive to the life cycle of the growth factor released by the self-derived platelet-rich plasma, so that the self-derived platelet-rich plasma positioned in the core layer can continuously and stably release the growth factor to maintain the higher concentration of the tissue cell growth factor, namely, the repair material shell layer formed by epsilon-polylysine and polycaprolactone and the repair material core layer formed by the self-derived platelet-rich plasma have specific correlation in terms of microstructure parameters and action mechanism, and the specific correlation is realized based on the processes that the fiber pore size of the shell layer is matched with the growth factor size, the degradation speed of the shell layer is adaptive to the life cycle of the growth factor released by the self-derived platelet-rich plasma and the like.

In summary, the repair material has excellent antibacterial property and can improve the wettability of polycaprolactone under the combination of polycaprolactone and epsilon-polylysine, so that wound tissue cells can show good biocompatibility with a shell layer of the repair material, cell adhesion and proliferation are facilitated, an activity-induced environment is provided for the conforming effect of growth factors released from a core layer of the repair material, the self-derived PRP of the core layer can also slowly and continuously release the growth factors, the self-derived PRP perfectly conforms to the wound environment of a patient without anaphylactic reaction, the content proportion of each growth factor meets the requirement of the wound environment, and the pertinence and the applicability of the growth factors to the activity induction of the wound tissue cells can be effectively ensured.

Example 3

The dressing of this embodiment is constructed by nanofibers based on coaxially arranged core and shell layers forming a core-shell structure, wherein the shell layer of the nanofibers comprises at least polycaprolactone for forming the shell body and epsilon-polylysine and zeolitic imidazolate framework material (ZIF-8) for modifying the polycaprolactone, and the core layer of the nanofibers comprises at least autologous platelet rich plasma for releasing growth factors.

Preferably, the zeolitic imidazolate framework material is disposed in the shell layer of the nanofiber in such a way that it is coated or embedded in an epsilon-polylysine modified polycaprolactone. The particle size range of the zeolite imidazole ester framework material is determined in a manner that the zeolite imidazole ester framework material can promote the diffusion release speed of the growth factors through the nanofiber shell layer without causing the wound tissue environment to extend to the inner side of the nanofiber shell layer. For example, the particle size of the zeolitic imidazolate framework material (ZIF-8) ranges from 5 to 30nm, preferably from 7 to 15nm. The zeolite imidazole ester framework material with the particle size range can be used for increasing the infiltration area of the nanofiber and improving the diffusion release speed of the growth factors from the inner side to the outer side of the nanofiber. If the particle size of the zeolite imidazole ester framework material is too small, the quality of the growth factor diffusion channel cannot be improved, and the improvement of the diffusion release speed of the growth factor is not facilitated; if the particle size of the zeolite imidazole skeleton material is too small, the mechanical properties of the nanofiber membrane are affected, and tissue fluid and biological enzymes which are kept outside the nanofiber shell layer based on the hydrophilic adhesion of the nanofibers can act on the autologous platelet-rich plasma inside along the channel formed by the zeolite imidazole skeleton material, so that adverse effects are caused on the diffusion and release of the growth factors and the beneficial effects caused by the promotion of the diffusion and release speed of the growth factors are offset.

Preferably, the shell layer of the nanofiber further comprises poly (propylene oxide) (PGL) uniformly arranged in the shell layer in a manner that can adjust the processability of the nanofiber shell layer and control the in-vivo and in-vitro degradation rate. Polycaprolactone (PCL) and monomers thereof are nontoxic, have good biocompatibility and biodegradability, PCL has good trafficability to small molecular medicines, can be used as an erodable medicine diffusion type slow release carrier, and PGL-PCL (Polyepoxypropanol-polycaprolactone) can improve processability and control in-vivo and in-vitro degradation rate, so that the medicine diffusion type slow release carrier can be differently arranged based on different repair positions and different repair periods of the same position.

The embodiment further improves the nanofiber dressing to improve the antibacterial property of the dressing and the tissue adhesion and improve the drug diffusion and slow release characteristics. For the nanofiber dressing prepared from polycaprolactone, epsilon-polylysine and autologous platelet-rich plasma, the autologous platelet-rich plasma rich in growth factors is distributed inside a nanofiber core layer, so that the growth factors need to take a nanofiber shell layer consisting of polycaprolactone and epsilon-polylysine as a medicine diffusion slow release carrier, and the growth factors inside the nanofiber shell layer can be stably and continuously diffused and released outside the nanofiber shell layer. In order to improve the diffusion range, release speed and other characteristics of the growth factors in the nanofiber core layer, the fiber pore diameter of the nanofiber shell layer should be suitable for autologous platelet-rich plasma and the nanofiber has good wettability; in order to promote the interaction of the growth factors and the wound tissues to promote the wound healing speed, the nanofibers should have a larger infiltration area to increase the adhesion and proliferation space of the cells of the wound tissues, so that the nanofibers can also increase the acting efficiency of the growth factors and the wound tissues based on the increase of the infiltration area.

As shown in fig. 2d, the growth factors released from the platelet-rich plasma for promoting tissue repair are mainly platelet growth factor PDGF-BB, which has mitogenic, differentiation, chemotactic and angiogenic effects, transforming growth factor TGF- β for regulating cell growth and differentiation, and vascular endothelial growth factor VEGF; the vascular endothelial growth factor VEG has high specificity on vascular endothelial cells and important biological functions of promoting vascular permeability, promoting proliferation of endothelial cells and the like. From the cumulative release profile of different growth factors in FIG. 2d, it can be seen that the release rate of PDGF-BB is faster than that of TGF-beta and VEGF in tissue fluid because PDGF-BB is biased to water-soluble and TGF-beta and VEGF are biased to fat-soluble; the PDGF-BB content is higher than TGF-beta and VEGF, the content difference and the specific proportion of the content are determined by the autologous platelet rich plasma from the patient, and the specific proportion is the optimal proportion for the patient and can effectively avoid the rejection. However, for the drug diffusion slow release carrier based on polycaprolactone and epsilon-polylysine, the time required for achieving higher content or higher concentration of the growth factors is longer, for example, the time required for achieving 80% maximum concentration of PDGF-BB, TGF-beta and VEGF is 15 days, 10 days and 10 days respectively, that is, in the initial stage of wound healing with the maximum demand of the growth factors, the diffusion release speed of the drug diffusion slow release carrier based on polycaprolactone and epsilon-polylysine for the growth factors is slower, and the growth factors with higher concentration cannot be provided in the initial stage of healing. Accordingly, improvements in the nanofiber shell layer are contemplated to improve the release rate of growth factors and the efficiency of promoting healing of drug diffusion slow release carriers based on polycaprolactone and epsilon-polylysine.

Metal-organic framework Materials (MOFS) are porous, crystalline materials formed by self-assembly of Metal ions or Metal clusters with multidentate organic ligands. The inorganic-organic hybrid material has the excellent properties of inorganic materials and organic materials, has high specific surface area, adjustable size and porosity, and high drug loading rate, and is easy to modify on the surface, so that the inorganic-organic hybrid material is widely applied to the fields of catalysis, gas capture, sensors, drug delivery and the like. The zeolite imidazole ester framework material (ZIF-8) is a metal-organic framework formed by coordination of zinc ions (Zn2+) and 2-methylimidazole (2-MiM), shows good biocompatibility and acid environment sensitivity, is stable under physiological conditions and disintegrates under the acid conditions, is an ideal carrier for drug transportation and slow release, and the size of the nano material is critical to the performance thereof, and the small size change can have decisive influence on the performance of the material, so that the particle size and size control of the ZIF-8 and the functional size composite regulation of the ZIF-8 and other materials have important significance for the application of the ZIF-8 and composite materials thereof in the biological molecular transportation process. The preparation method of ZIF-8 comprises a solvothermal synthesis method, a microwave auxiliary method and microfluidic control, and the particle size regulation and control mode comprises the steps of reaction parameter adjustment, surfactant regulation and crystallization regulator participation, so that ZIF-8 with the particle size ranging from 10nm to 1 mu m can be prepared.

Therefore, ZIF-8 with a selected particle size range is added into the shell solution to be uniformly mixed and is prepared into the shell of the nanofiber based on coaxial electrostatic spinning, so that the PCL-epsilon-PL nanofiber coated or embedded by the ZIF-8 shows a large specific surface area, the drug loading rate of the nanofiber is improved from 15% to 25%, and the ZIF-8 can also be selected to increase the number of channels and the quality of channels for diffusion and release of the growth factors from the inner side of the shell of the nanofiber to the outer side of the shell based on the particle size in a specific range. The ZIF-8 coated or embedded PCL-epsilon-PL nanofiber also obviously increases the infiltration area and adhesion space of tissue cells in the nanofiber shell layer, so that the interaction between the growth factors and wound tissues is improved. The antibacterial experiment shows that ZIF-8 and epsilon-PL show dual antibacterial properties, epsilon-PL is used as a polypeptide to be loaded on ZIF-8 to further kill residual bacteria, so that the dressing prepared from the PCL-ZIF-8-epsilon-PL nanofiber can improve the barrier capability to external bacteria and the killing effect to internal bacteria, and can prevent the infection of external bacteria to wounds to show high-efficiency sterilization properties. The drug diffusion slow release carrier based on PCL-ZIF-8-epsilon PL nanofiber can shorten the wound healing time from 22 days to 17 days through the improvement of antibacterial performance, the increase of infiltration area and the improvement of growth factor release speed.

It should be noted that the above-described embodiments are exemplary, and that a person skilled in the art, in light of the present disclosure, may devise various solutions that fall within the scope of the present disclosure and fall within the scope of the present disclosure. It should be understood by those skilled in the art that the present description and drawings are illustrative and not limiting to the claims. The scope of the invention is defined by the claims and their equivalents.

Claims

1. A repair material, the repair material comprising:

at least a nuclear layer for providing growth factors;

a shell layer allowing at least the growth factors of the core layer to pass therethrough and be released;

the repair material is configured into a nanofiber with a core-shell structure based on the core layer and the shell layer in a mode of at least comprising coaxial arrangement.

2. The repair material of claim 1 wherein the shell comprises at least a first component for forming a shell body and a second component for modifying the first component;

the core layer includes at least a third component for releasing the growth factor.

3. The repair material of claim 1 or 2 wherein the first component is configured as polycaprolactone, the second component is configured as epsilon-polylysine, and the third component is configured as autologous platelet rich plasma.

4. A repair material according to any of the preceding claims 1 to 3, wherein the nanofibers have a diameter of 0.2 to 1.2 μm.

5. Repair material according to one of the preceding claims 1 to 4, characterized in that the diameter of the nanofiber core layer is 0.1 to 1.0 μm and the thickness of the nanofiber shell layer is 0.01 to 0.5 μm.

6. Repair material according to one of the preceding claims 1 to 5, characterized in that the shell layer of the nanofibres is configured as a porous structure, the fibre pore size of the shell layer being 4-10 nm;

the water contact angle of the shell layer of the nanofiber is 40-80 degrees.

7. A method for preparing a repair material, characterized in that the method is used for preparing a repair material according to one of claims 1 to 6, comprising the steps of:

8. The process according to claim 7, wherein in step a,

the mass ratio of polycaprolactone, epsilon-polylysine and medical acetone is (3-50): (1-5): (10-300);

the mixing is carried out by adopting a stirrer, and the stirring time is 10-15 hours.

9. The process according to claim 7 or 8, wherein in step b,

the mass concentration of the polyvinyl alcohol solution is 1% -30%;

the mass ratio of the polyvinyl alcohol solution to the autologous platelet-rich plasma is (1-5): (1-20).

10. The process according to any of the preceding claims 7 to 9, wherein in step c,

the spinning voltage of coaxial electrostatic spinning is 8-25 kv;

the flow rate of the shell layer solution and the flow rate of the core layer solution of the coaxial electrostatic spinning are respectively 0.3-0.8 ml/h and 0.8-2.0 ml/h;

the distance between the coaxial electrostatic spinning needle head and the receiving electrode is 8-25 cm.