Synthesis And Characterization The Properties Of Biodegradable Polyester Used For Mesh

With the rapid development of synthetic polymer materials,it has been difficult to reconcile the current energy,economic and environmental problems.Biodegradable biodegradable aliphatic polyesters have become the focus of research and development.Because polybutylene succinate(PBS)has good biodegradability,excellent mechanical properties and ease of processing and molding,it has become a hot research field in the field of biomedical polymer materials.However,the basic research of PBS polyester system In addition,modern medicine has put forward further requirements for biological materials,and hopes to introduce active reaction sites into the materials.On the one hand,the proportion of reactive sites can be adjusted to adjust the hydrophilic balance of the materials.The surface Charge distribution and degradation cycle to promote the cell life on the material adhesion and growth and improve the biocompatibility;the other hand,through the reactive sites and peptides,amino acids,antibacterial agents and other specific activity of the chemical reaction,the use of specific Sexual identification can produce a functional tissue engineering scaffold with both targeted and controlled release.Based on the above two requirements,this dissertation will systematically study the structural properties of PBS polyesters,and synthesize polybutylene succinate-co-aspartate by introducing amino reactive sites in the main chain of PBS Glycolic ester(PBSA),and further study the structure and properties of the copolyester.The specific research contents are as follows:(1)PBS polyesters were prepared by melt polycondensation.The results show that the synthesized polyesters have high molecular weight,and the thermal properties and crystal structure of the polyesters are studied,which is in line with the basic conditions for the further application in the biomedical field.(2)In order to further meet the requirements of biomedical materials for the development of modern medicine,PBSA copolyesters with amino active site were synthesized in this thesis.Differential scanning calorimetry(DSC)and thermogravimetric analysis(TGA))Studied the thermal properties and thermal stability of copolyesters.Studies have shown that the melting point and thermal stability of PBSA copolyester slightly lower than the PBS polyester,but still meet the polymer polymerization or spinning temperature and thermal stability.The wide-angle X-ray diffraction(WAXD)test shows that the crystalline structure of PBSA copolyester is still monoclinic structure of PBS polyester.(3)Further study on the cytotoxicity,hydrophilicity and degradation properties of PBS and PBSA copolyesters to explore the feasibility of the material in the biomedical field,the paper also explored the amino group in the main chain of the macromolecule The role and content of the above performance.The study found that PBSA copolyester had better hydrophilicity than PBS polyester after deprotection treatment and further enhanced its hydrophilicity with the increase of aspartic acid content.Degradation experiments showed that PBSA copolyester had better degradation effect than PBS polyester in lipase buffer solution,and the degradation of copolyester was better with the increase of grafting amount of aspartic acid.PBS and PBSA copolyester cytotoxicity test showed that the cell viability of the copolyester PBSA-13> PBSA-10> PBSA-7> PBS,PBS introduced on the reactive site of amino groups to improve the hydrophilicity of the material,Changing the charge distribution on the surface of the material,promoting the adhesion and growth of the cell living material on the material,making the cell survival rate greatly increased.In summary,the use of specific recognition is expected to synthesize a functional tissue engineering scaffold with both targeted and controlled release.(4)The PBSA copolyester was deprotected by trifluoroacetic acid solution with volume fraction of 10%,and the presence of exposed amino groups on the macromolecular chains was confirmed by ninhydrin chromogenic reaction combined with infrared characterization.The test showed that 10% After 35 minutes of trifluoroacetic acid treatment,the amino groups in the copolyester were almost completely exposed.(5)The broad-spectrum antibacterial agent levofloxacin(LV)was grafted into PBSA to give long-lasting and stable antibacterial activity of the copolyester.The specific scheme is that the carboxyl group in the LV structure is activated by the activator HOBT It was reacted with a copolyester having a naked amino group to prepare a copolyester(PBSA-g-LV)grafted with an antibacterial agent.The antibacterial properties,cytotoxicity and spinnability of the synthesized product were studied.The results showed that the PBSA-co-LV copolyester has broad-spectrum antibacterial effect and the material has spinnability.