A kind of modified polycarbonate with highly blood coagulation resistant
Technical field
The present invention relates to biomedical engineering functional material technical field of modification, more particularly, to a kind of changing for polycarbonate
Property.
Background technique
Biodegradable aliphatic polycarbonate has good biological degradability, excellent biocompatibility and physical machine
Tool performance is a kind of important biodegradable medical macromolecular materials, oneself is in hypodermal contraception implants, three-dimensional tissue's engineering branch
The fields such as frame, neural restoration and drug controlled release show greatly application and potentiality.Most common and wide research can
Biodegradable aliphatic polycarbonates are polytrimethylene carbonate (PTMC), a kind of amorphous state or with crystallizing a little
Polycarbonate, glass transition temperature be about -17 DEG C, room temperature and in vivo under the conditions of have good elasticity.Meanwhile
PTMC degradation in vivo will not release acid and cause acid rise in part and the degradation behavior automatically speeded up be caused to occur,
And its degradation model is surface erosion, and during degradation, although material is weightless, molecular weight is held essentially constant, thus
It is set to be always maintained at higher mechanical property during degradation.But there is no functional groups, material on the main chain of PTMC
The disadvantages of surface hydrophilicity is weak and cannot be grafted drug or other function substance, is limiting its popularization.Fredrik
Nederberg et al. (Organo Hydrogel Hybrids.Formation of Reservoirs for
ProteinDelivery [J] .Biomacromolecules, 2005,6 (6): 3088-3094.) by hydrophobic PTMC
It is modified, the PTMC blocked with hydrophily Phosphorylcholine group (PC) has been synthesized, a kind of biodegradable organic water-setting has been made
Glue hybrid material.This hydrogel hybrid material is to have synthesized hydroxy-end capped PTMC first, so using 1,4-butanediol as initiator
The PTMC of Phosphorylcholine sealing end is synthesized by the chloro- 2- oxygen -1,3,2- dioxaphospholane of 2- afterwards.It will be apparent that poly- for this
It closes for object, has on a polymer chain and most only there are two Phosphorylcholine group, so low PC grafting rate is unsatisfactory for it
As bio-medical material for clinical use.And do not have on polymer chain other can functionalization group, cannot be subsequent
It is grafted large biological molecule or other function molecule provides reaction site.Therefore it is big to need to prepare a kind of research potential, it is derivative
The wide modified polycarbonate with highly blood coagulation resistant of energy.
Summary of the invention
The purpose of the present invention is to provide a kind of synthesis is simple, without being protected and being deprotected to functional group, can be again
The bionical polycarbonate of the better phosphatide of functionalization, biocompatibility.Its technical solution is: a kind of with highly blood coagulation resistant
Modified polycarbonate is linear carbonate polymer comprising main chain, and side chain includes can functionalization double bond and hydrophilic
Phosphorylcholine group has following monomer structure, including copolymer A, B and C:
Its preparation process are as follows: be first copolymerized by trimethylene carbonate (TMC) and trimethylene derivative, then pass through two sulphur
The click chemistry of pure and mild double bond reacts grafting 2- methylacryoyloxyethyl Phosphorylcholine (MPC) on copolymer side chain and obtains mesh
Mark the modified polycarbonate that product has highly blood coagulation resistant.
The trimethylene derivative includes: 5- methyl -5- allyloxy carbonyl -1,3- dioxanes -2- ketone, 5- allyl oxygen
Base carbonyl -1,3- dioxanes -2- ketone or 5- acryloyloxymethyl -1,3- dioxanes -2- ketone or 5- methacryloxymethyl -
1,3- dioxanes -2- ketone or 5- acryloyl-oxy -1,3- dioxanes -2- ketone or 5- methacryloxypropyl -1,3- dioxanes -2-
Ketone.
Two mercaptan includes: 1,2- dithioglycol, 1,3- dimercaptopropane and 1,4- succinimide mercaptans.
Its synthesis step includes synthesizing a cyclic carbonate monomer containing alkene first, then the novel cyclic carbonic acid
Ester monomer contains alkene copolymer at side chain with trimethylene carbonate ring-opening polymerisation by a certain percentage, to introduce in the side chain double
The click chemistry reaction of key, mercaptan and double bond finally by both ends with sulfydryl has hydrophily in side chain graft containing alkene copolymer
MPC.
The beneficial effects of the present invention are:
1) main polymer chain is linear macromolecule polyalcohol, has good elasticity.The polymer can pass through
It adjusts monomeric species and ratio and the amount of side chain Phosphorylcholine group changes the performance of polycarbonate, improve polycarbonate and make
For the anticoagulation ability of biodegradable medical macromolecular materials;Double bond on the polymer lateral chain can be big for subsequent grafting biology
Molecule or other function molecule provide reaction site, and research potential is big, and derivative performance is wide.
2) the bionical carbonate polymer of phosphatide has outstanding anticoagulant effect, biology compared with the PTMC before modification
Compatibility is more preferable.
Detailed description of the invention
Fig. 1 has the modified polycarbonate A (R=CH of highly blood coagulation resistant3, n=0) coating surface platelet adhesion reaction
The fluorogram of 45min.Wherein, SS:316 stainless steel;PTMC: polytrimethylene carbonate;PTMMAC:TMC's and MAC is random total
Polymers;A (R=CH3, n=0): the PTMMAC of Phosphorylcholine base group modification.
Fig. 2 has the modified polycarbonate A (R=CH of highly blood coagulation resistant3, n=0) coating surface platelet adhesion reaction
The SEM electron microscope of 45min.
Trimethylene derivatives monomer structural formula used in Fig. 3.
Specific embodiment
Embodiment 1
A.5- the synthesis of methyl -5- allyloxy carbonyl -1,3- dioxanes -2- ketone (MAC)
It is the evil of Material synthesis 5- methyl -5- allyloxy carbonyl -1,3- two with 2,2- (double methylols) propionic acid (bis-HPA)
Alkane -2- ketone (MAC).This monomer for the side chain of polycarbonate provide can functionalization double bond.
The preparation of b.TMC and MAC random copolymer
It weighs a certain amount of TMC and MAC monomer (molar ratio 3:1) and a clean and dry magnetic stirrer is placed in
In the single-necked flask of the special drying sealed with rubber stopper, reaction unit with oil pump take out half an hour vacuum after, respectively
Catalyst and initiator are dissolved in dry n-hexane and diluting, and stannous octoate (4 × 10 is added by every mole of monomer with syringe- 4Mol catalyst), n-octyl alcohol (2 × 10-5Mol initiator) be injected into reaction unit after, extract syringe, with vacuum ester seal,
Continue after vacuumizing a hour, stop vacuumizing, seals.Then, reaction unit, which is placed in oil bath pan, is warming up to 115 DEG C, instead
Answer 12h.After reaction, it is cooled to room temperature, after dissolving polymer with chloroform, sedimentation is added dropwise into cold alcohol solvent for solution,
Product vacuum is dry, obtains copolymer and is named as PTMMAC.(the practical ratio of components of copolymer is TMC:MAC=2.08:1.Divide equally again
Son amount Mw=81.9KD)
C. the preparation of Thiolation -2- methylacryoyloxyethyl Phosphorylcholine (ETPC)
1,2- dithioglycol (9.42g, 100mmol) and 2- methylacryoyloxyethyl Phosphorylcholine (MPC) (14.76g,
50mmol) be placed in 250ml single-necked flask, be added 100ml chloroform (solvent), then be added diisopropylamine (278.8uL,
Alkaline environment 2.0mmol) is provided, is placed in oil bath pan and is warming up to 25 DEG C, reaction for 24 hours, after reaction, is settled with acetone, is led to
Column Chromatographic purification product is crossed, then is dried in vacuo, ETPC obtained.
D. with the modified polycarbonate A (R=CH of highly blood coagulation resistant3, n=0) preparation
Reaction dissolvent 300ml (chloroform: anhydrous second is added in ETPC (0.42g, 1mmol) and PTMMAC (5g, 0.06mmol)
Alcohol (5:1)), then be added diisopropylamine (29.5ul, 0.21mmol) provide alkaline environment, 25 DEG C of reaction temperature, the reaction time
For 24 hours, after reaction, solution is concentrated, cold ethyl alcohol sedimentation, and product vacuum is dry.Obtain target product A (R=CH3, n=0).
(MPC grafting rate=side chain structural unit containing MPC amount/total structural unit amount=1.8% of polymer)
After tested: target product has excellent anticoagulant effect.
It is described further in conjunction with attached drawing 1 and Fig. 2 as follows:
There is the modified polycarbonate A (R=CH of highly blood coagulation resistant in conjunction with attached drawing 13, n=0) coating surface blood platelet it is viscous
As can be seen that A (R=CH in the fluorogram of attached 45min3, n=0) coating surface platelet adhesion reaction quantity far less than SS,
The platelet adhesion reaction quantity on the surface PTMC and PTMMAC.
There is the modified polycarbonate A (R=CH of highly blood coagulation resistant in conjunction with attached drawing 23, n=0) coating surface blood platelet it is viscous
In the SEM electron microscope of the attached 45min as can be seen that surface SS, platelet aggregation and activation degree are the most serious;PTMC coating surface
There are the aggregation and activation of most of blood platelet;Most of blood platelet of PTMMAC coating surface has also stretched out pseudopodium;And there is height
Modified polycarbonate A (the R=CH of anticoagulant property3, n=0) coating surface blood platelet at normal plate-like, do not extend out pseudopodium more
Do not occur assembling and being activated.
Therefore, with the modified polycarbonate A (R=CH of highly blood coagulation resistant3, n=0) and there is excellent anticoagulant effect.
Although the anticoagulant effect of subject polymer is by its random copolymer A (R=CH3, n=0) measurement, but subject polymer
Anticoagulant effect should be not excluded for random copolymer, alternate copolymer, block copolymer and the graft copolymerization species of its A, B and C
Type.