Synthesis and Characterization of Poly （L-lactide-co-glycolide）

Poly （ l- lactide- co-glycolide ） （ PLGA ） with different compositions was prepared using stannous octaoate as catalyst by bulk ring-opening copolymerization of l-lactide and glycolide. The structure and properties of the PLGA copolymers were cbaracterized by means of attenuated total reflectance-Fourier transform infrared （ATR-FTIR）, ^1H NMR, differential scanning calorimeter （ DSC and X-ray diffraction （XRD） methods, The experimented results indicate that the synthetic conditions and the composition of copolymers have art obvious influence on the structure of PLGA copolymers, The degradation rate of eopolymers increased with the increasing of the glycolide component in the copolymers.     

Synthesis and Characterization of Poly(L-lactide-co-ε-caprolactone) Copolymers

1Introduction Biodegradablepolymersareusedinanincreasinglylargenumberofbiomedicalapplicationssuchasdrug re leasingimplants,bioresorbablesurgicalsutures,shorttermfixationdevicesintheorthopaedicfieldandothernovel applications[1,2].Inthefamilyofbiodegradable…     

Synthesis and Characterization of a Biodegradable Copolymer： RGD Peptide Modification of Poly （lactic acid-co-lysine）

The poly （ lactic acid-co-lysine） was synthesized using lR and ^1H NMR to characterize the copolymer. And then the RGD modification copolymer RGD- PIAL was prepared. The contact angles were used to see the RGD modification occurrence. Also high molecular weight polymer was controlled to the reaction of polymerization of copolymer.     

Composites of Nano-hydroxyapatite and Poly（ε-caprolactone） Composite Fibers by Electrospinning

用水热法合成的棒状纳米羟基磷灰石（nHA）,引发ε-己内酯（ε-CL）开环聚合得到nHA-PCL复合材料。用静电纺丝法分别制备了聚己内酯（PCL）、nHA/PCL共混材料和nHA-PCL复合材料的3种电纺纤维膜。通过FT-IR、DSC、SEM、TGA和拉伸试验机表征了样品的结构、热性能和力学性能。结果表明：nHA-PCL电纺膜的结晶性能优于nHA/PCL材料,且热稳定性和力学性能都优于其他两种膜,nHA-PCL电纺膜的完全分解温度为420°C,拉伸强度和断裂伸长率分别达到28.2MPa和55.6%。3种膜的纤维直径均小于500 nm,nHA-PCL电纺膜的纤维表面比较粗糙。在人体仿生液中诱导矿化4 d后,nHA-PCL电纺膜纤维表面出现磷灰石沉积,而纯PCL和共混nHA/PCL电纺膜的纤维表面沉积的磷灰石很少,nHA-PCL复合电纺膜具有较好的诱导成骨性能。     

Biologically Inspired Self-assembling Synthesis of Bone-like Nano-hydroxyapatite/PLGA- （PEG-ASP）n Composite： A New Biomimetic Bone Tissue Engineering Scaffold Material

A new biomimetic bone tissue engineering scaffold material, nano-HAI PLGA-（ PEG-Asp ）n composite, was synthesized by a biologically inspired self-assembling approach. A novel biodegradable PLGA- （ PEG-Asp ）n copolymer with pendant amine functional groups and enhanced hydrophilicity woo synthesized by bulk ring-opening copolymerization by DL-lactide（ DLLA） and glycolide（ GA ） with Aspartic acid （ Asp ）-Polyethylene glycol（PEG） alt-prepolymer. A Three-dimensional, porous scaffold of the PLGA-（ PEG- Asp）n copolymer was fabricated by a solvent casting , particulate leaching process. The scaffold woo then incubated in modified simulated body fluid （naSBF）. Growth of HA nanocrystals on the inner pore surfaces of the porous scaffold is confirmed by calcium ion binding analyses, SEM , mass increooe meoourements and quantification of phosphate content within scaffolds. SEM analysis demonstrated the nucleation and growth of a continuous bonelike, low crystalline carbonated HA nanocrystals on the inner pore surfaces of the PLGA- （ PEG-Asp ）n scaffolds. The amount of calcium binding, total mass and the mass of phosphate on experimental PLGA- （ PEG-Asp ） n scaffolds at different incubation times in mSBF was significantly greater than that of control PLGA scaffolds. This nano-HA/ PLGA-（ PEG- Asp ）n composite stunts some features of natural bone both in main composition and hierarchical microstrueture. The Asp- PEG alt-prepolymer modified PleA copolymer provide a controllable high surface density and distribution of anionic functional groups which would enhance nucleation and growth of bonelike mineral following exposure to mSBF. This biomimetic treatment provides a simple method for surface functionalization and sabsequent mineral nucleation and self-oosembling on bodegradable polymer scaffolds for tissue engineering.     

Preparation and characterization of poly（D,L-lactide） and its porous biomaterials

1　INTRODUCTIONPolylactides(PLA) have become very impor tant biomedical materials due to the combination oftheir bioresorbable, biocompatible, biodegradableand mechanical properties. They have been widelyused in drug controllable release, surgical suture,orthopedics bone internal fixation and tissue engi neering[1 5]. 2 methods are currently available forPLA synthesis: polycondensation ( condensationpolymerization) of lactic acids(direct method) andring opening polymeriz…