CN110038169A - Medical enhanced degradable GTR/GBR integrated film and preparation method thereof - Google Patents

Abstract

The invention discloses a medical enhanced degradable GTR/GBR integrated film and a preparation method thereof. Aiming at the problems that the degradable film in the current market has low strength and can not keep the integrity of the film for a long time; the non-degradable membrane needs a secondary operation, is easy to cause infection, increases the pain of patients and the like, develops a GTR/GBR integrated membrane which has higher strength and degradability, combines the advantages of the degradable membrane and the non-degradable membrane material as much as possible, and has high strength and proper price.

Description

Medical enhanced degradable GTR/GBR integrated film and preparation method thereof

technical field

The invention relates to the technical field of medical materials, in particular to a medical-enhanced degradable GTR/GBR integrated film and a preparation method thereof.

Background technique

At present, the existing technology in the industry:

GTR/GBR membranes are mainly used in the surgical treatment of periodontal tissue regeneration. In periodontal surgery, the membrane material is used as a barrier to block the contact between the gingival connective tissue and the root surface, and to provide a certain space to guide the periodontal ligament cells with the ability to form new attachments to preferentially occupy the root surface, so that when the periodontal ligament has been exposed to the periodontal surface New cementum is formed on the root surface in the bag, and periodontal ligament fibers are embedded to form the regeneration of periodontal tissue, that is, the formation of new attachment healing.

GTR/GBR membrane is mainly based on the characteristics of different migration speeds of various types of tissue cells, preventing connective tissue cells and epithelial cells that migrate faster from entering the bone defect area, allowing osteoblasts to preferentially enter the bone defect area, and growing without competition to achieve defects. Regional bone reparative regeneration.

GTR/GBR membrane materials are divided into non-degradable membranes and degradable membranes according to their degradation characteristics

1. Non-degradable membrane: Today's non-degradable membranes mainly include PTFE (polytetrafluoroethylene membrane), titanium mesh and titanium reinforced expanded polytetrafluoroethylene membrane.

2. Degradable film: The materials of degradable film mainly include natural polymer materials and synthetic polymer materials.

The advantages and disadvantages of degradable film and non-degradable film are shown in Table 1:

To sum up, the problems of the existing technology:

1. The non-degradable membrane cannot be degraded in the body and needs to be removed by a second operation. It is easy to cause re-infection, and it is easy to cause the wound to open, resulting in early exposure of the membrane and poor cell affinity.

2. The degradable membrane has poor strength and is mainly used for small-area alveolar bone resorption, which cannot provide a good growth space for large-area alveolar bone resorption, and has poor clinical effect.

3. The currently popular GTR/GBR membranes on the market are expensive and expensive, which limits clinical applications.

SUMMARY OF THE INVENTION

In view of the above shortcomings, the present invention is aimed at the low strength of the degradable film on the market, and the integrity of the film cannot be maintained for a long time; the non-degradable film requires a second operation, which easily leads to infection and increases the pain of patients. A GTR/GBR integrated membrane with high strength and degradability has been developed. This integrated membrane combines the advantages of degradable membrane and non-degradable membrane materials as much as possible, and has high strength and reasonable price.

The technical solution adopted by the present invention to solve the technical problem is: a medical-enhanced degradable GTR/GBR integrated membrane, the integrated membrane includes polylactic acid and a magnesium alloy orifice plate wrapped in it, and the two are integrally formed.

A preparation method of a medical-enhanced degradable GTR/GBR integrated film, comprising the following steps:

(1) Make polylactic acid into a solution;

(2) First lay a layer of 0.12-0.15mm thick polylactic acid solution in the metal mold, then place a magnesium alloy orifice plate, and then lay a layer of 0.12-0.15mm thick polylactic acid solution on the magnesium alloy mesh;

(3) The metal mold was then placed in a drying oven at 100° C. for 6 hours, and the solvent was evaporated to obtain an integrated film.

The preparation method of the polylactic acid solution is as follows: the polylactic acid particles are dissolved in an acetone solution with a purity of 99%, heated to 50° C. and vigorously stirred for 4 h to prepare a polylactic acid solution with a mass fraction of 40%-50% for use.

The preparation method of the magnesium alloy orifice plate is as follows:

(1) Cast a magnesium alloy with a weight ratio of 90wt% magnesium powder, 9wt% aluminum powder, and 1wt% zinc powder into a magnesium alloy plate, and cut it into magnesium bars of 30×4×0.9mm;

(2) Use a metal puncher to punch holes on the magnesium strip, the hole diameter is 0.5mm, to make a magnesium alloy orifice plate;

(3) Grind the rough parts on the edges, wash with 35% hydrochloric acid, sterilize with ultraviolet rays, and dry for use.

A gingival tissue bed made of a medical-enhanced biodegradable GTR/GBR integrated membrane.

The medical-enhanced degradable GTR/GBR integrated membrane invented and created in this experiment not only has degradability, biocompatibility, degradability, non-toxicity to cells, but also has high strength, which can be better suitable for periodontal guidance Tissue regeneration surgery provides a good time and space for the regeneration of periodontal tissue and bone. Moreover, the price is low, the process is simple, and it has operability.

(1) Biodegradable

The materials used in this invention are polylactic acid and metal magnesium alloy, which can be completely degraded in the human body, and the degradation rate is coordinated with the regeneration process of bone tissue. The human bone regeneration cycle is about 17 weeks. The polylactic acid in this invention is a biodegradable and bioactive thermoplastic aliphatic polyester. It is a renewable substance and degrades slowly in the body. The degradation time is about 3-4 months. Magnesium has active chemical properties, and its standard electrode potential is -2.37V (SCE), which is prone to corrosion in corrosive media. The advantage of the degradable membrane over the non-degradable membrane is that the process of removing the membrane in the second operation is omitted, the treatment time is shortened, the operation risk is reduced, and the pain of the patient is reduced. Therefore, clinicians and patients currently prefer degradable membranes in guiding tissue regeneration.

(2) has high mechanical strength

Compared with the traditional metal bone repair material, the metal magnesium of the barrier membrane material has an elastic modulus close to that of human cortical bone, which can effectively avoid the stress shielding effect. The body fluid immersion experiment shows that, compared with a single polylactic acid film, the bending strength of the material of the present invention increases significantly with the body fluid immersion time, which can effectively solve the problem of the support strength of the bone tissue growth space. Therefore, the material of the present invention has higher mechanical properties.

(3) Good biocompatibility

The degradation product of polylactic acid is lactic acid, which can enter the tricarboxylic acid cycle and then be decomposed into carbon dioxide and water and excreted. Magnesium is one of the essential nutrients for the human body, and its content in the body is second only to calcium, potassium and sodium. Magnesium can catalyze and activate more than 300 enzymes, necessary catalysts for cell metabolism activities, and participate in various physiological activities such as protein and DNA synthesis, energy storage and transportation, nerve signal transduction, and muscle contraction. Lack of magnesium may cause arrhythmia, hypertension, ischemic heart disease, osteoporosis, etc. The World Health Organization recommends 280mg-300mg of magnesium per day for adults and 250mg for children. Therefore, polylactic acid and magnesium have good biosafety and are the basis of biocompatibility.

In the present invention, holes are punched on the magnesium alloy of the experimental model with a diameter of 0.5 mm, and a magnesium hole plate is made to provide channels for the nutritional components of osteoblasts.

The biosafety of the material is tested according to ISO 10993-5. The safety of cells shows that the material of the present invention is non-toxic and has good biocompatibility, and can provide a good living environment for periodontal tissue and bone tissue.

Description of drawings

Figure 1A is a 3D model of a medical-enhanced biodegradable GTR/GBR integrated membrane;

Figure 1B is a front view of a medical-enhanced biodegradable GTR/GBR integrated film;

Figure 1C is a side view of the medical-enhanced biodegradable GTR/GBR integrated film;

Figure 1D is a top view of the medical-enhanced biodegradable GTR/GBR integrated film;

Figure 2 is a physical model of a medical-enhanced biodegradable GTR/GBR integrated membrane.

Figure 3 is a graph showing the linear variation of the maximum load of each barrier film with the immersion test in the three-point bending test.

In the figure, the coated group is the Mg+PLA group; the uncoated group is the Mg group; the non-Mg group is the PLA group.

Figure 4 shows the proliferation of mouse fibroblasts L929 and osteoblasts MC3T3-E1 on membrane materials by WST method to evaluate the biosafety of the materials.

In the figure, a is a mouse fibroblast cell line (L929) b is a mouse osteoblast cell line (MC3T3-E1)

The coated group was the Mg+PLA group; the uncoated group was the Mg group; the non-Mg group was the PLA group; the Ti group was the medical titanium group.

Detailed ways

The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments:

As shown in the figure is a specific embodiment of the present invention,

In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be described in detail below with reference to examples. It should be understood that the experimental cases herein are only used to explain the present invention, but not to limit the present invention.

A medical-enhanced degradable GTR/GBR integrated film, the integrated film includes polylactic acid and a magnesium alloy orifice plate wrapped in it, and the two are integrally formed. The specific preparation steps of the integrated film are as follows:

1. Dissolve the polylactic acid particles in an acetone solution with a purity of 99%, heat to 50 °C and stir vigorously for 4 h to prepare a polylactic acid solution with a mass fraction of 40%-50% for use.

1, 2. The customized magnesium alloy (AZ91) was used as the experimental material, and its casting weight ratio was 90wt% of magnesium powder, 9wt% of aluminum powder, and 1wt% of zinc powder. It was cut into magnesium strips of 30×4×0.9mm and punched with a metal hole punch with a diameter of 0.5mm. Made of magnesium alloy orifice plate. The rough edges are polished, cleaned with 35% hydrochloric acid, sterilized with ultraviolet rays, and dried for later use.

3. Pour the mixed polylactic acid solution into a metal mold, then place a magnesium alloy orifice plate, and then spread a layer of polylactic acid solution on the magnesium alloy orifice plate. Pour the polylactic acid solution with a thickness of 0.12-0.15mm each time.

2.4. It was placed in a drying oven at 100 °C for 6 h, and the solvent was evaporated to obtain a polylactic acid film.

3.5. The samples were rinsed at least 5 times in distilled water to remove acetone.

6. Store in calcium oxide for later use.

The principle of the present invention is to use polylactic acid to dissolve in acetone solution, and to form a film at a temperature of 100° C., and to combine with the magnesium mesh, which is not easy to separate, and the combination is more uniform.

Detection analysis:

Figure 3 shows the linear variation of the maximum load of each barrier film with the immersion test in the three-point bending test. The coated group is the material of the present invention, and its strength is the highest; the strength of the uncoated group and the non-Mg group is lower than that of the coated group. Through the bending strength experiment, it is concluded that the material of the present invention has significantly higher strength than a single polylactic acid film, and can solve the problem of the support strength of the bone tissue growth space.

As shown in Figure 4, through the biosafety experiment of the present invention, it is found that the material of the present invention is non-toxic, can support mouse fibroblasts and mouse osteoblasts, and its surface adheres to the uncoated group and the non-Mg group for a long time. In contrast, the coated fibroblasts grew more stably. Moreover, the biocompatibility is comparable to that of titanium alloys, providing a good biological environment for cells. It is proved that the cytocompatibility of this barrier membrane is good. Therefore, the cell affinity of the medical-enhanced degradable GTR/GBR integrated membrane is sufficient to be used as a medical GTR/GBR membrane.

Claims (5)

1. A medical-enhanced degradable GTR/GBR integrated film, characterized in that, the integrated film contains polylactic acid and a magnesium alloy orifice plate wrapped in it, and the two are integrally formed. 2. a preparation method of medical enhanced degradable GTR/GBR integrated film as claimed in claim 1, is characterized in that, comprises the following steps: The polylactic acid is made into a solution; First lay a layer of 0.12-0.15mm thick polylactic acid solution in the metal mold, then place a magnesium alloy orifice plate, and then lay a layer of 0.12-0.15mm thick polylactic acid solution on the magnesium alloy orifice plate; Then, the metal mold was placed in a drying oven at 100° C. for 6 h, and the solvent was evaporated to obtain an integrated film. 3. the preparation method of medical-enhanced degradable GTR/GBR integrated film according to claim 2, is characterized in that: the preparation method of described polylactic acid solution is as follows: polylactic acid particle is dissolved in 99% acetone solution with purity , heated to 50 °C and vigorously stirred for 4 h to prepare a polylactic acid solution with a mass fraction of 40%-50% for use. 4. the preparation method of the medical-enhanced degradable GTR/GBR integrated film according to claim 2, the preparation method of the magnesium alloy orifice plate is as follows: A magnesium alloy with a weight ratio of 90wt% of magnesium powder, 9wt% of aluminum powder and 1wt% of zinc powder is cast into a magnesium alloy plate, and cut into magnesium bars of 30×4×0.9mm; Use a metal puncher to punch holes on the magnesium bar, the hole diameter is 0.5mm, to make a magnesium alloy hole plate; The rough parts on the edges were polished, washed with 35% hydrochloric acid, sterilized with ultraviolet rays, and dried for later use. 5. A gingival tissue bed made of the medical-enhanced degradable GTR/GBR integrated membrane according to claim 1.