改进溶剂浇铸/粒子沥滤法制备聚ε-己内酯组织工程支架

对经典的溶剂浇铸／粒子沥滤法进行适当改进，结合致孔剂直接黏结工艺制备三维多孔聚ε-己内酯（PCL）组织工程支架材料.以氯化钠为致孔剂，利用预成型-真空浇铸-脱溶荆工艺制得支架材料．对支架的微结构、孔径、孔隙率和亲水性等性能进行表征．结果表明，黏结工艺中加入水量在2％～8％时都可形成均匀多孔黏结结构，且支架孔隙率几乎不变；支架孔径基本分布在10～80μm；孔隙率可达（89±1）％；采用抽真空与加热相结合的脱溶荆工艺可以提高孔隙率．制得的PCL支架厚度2〉5mm且为三维高孔隙率海绵体结构，可适用于软组织工程的修复．     

溶剂浇铸-粒子沥滤法制备PBS/PCL组织工程支架

选用聚丁二酸丁二醇酯(PBS)/聚ε-已内酯(PCL)共混材料作为组织工程支架材料基质,氯化钠和葡萄糖颗粒作为致孔剂,在传统的溶刺浇铸-粒子沥滤法的基础上,通过调节PBS/PCL的质量分数制得了不同尺寸且孔径、孔隙率满足组织工程支架要求的PBS/PCL多孔支架.对多孔支架的微结构、孔径、孔形态和素水性进行了表征,研究了PBS/PCL的质量分数、致孔剂粒径对支架成型及孔隙率的影响.结果表明,PBS/PCL的质量分教对支架成型影响较大,过低或过高的质量分数都会导致支架成型性差,质量分数在6%～10%时支架成型较好.利用质量分数为8%的PBS/PCL溶液可以制备形状复杂的多孔支架.所制支架内部孔洞分布均匀,贯通性好,孔径可由致孔剂的粒径来调控,支架孔隙率为86%～93%.支架亲水性良好,吸水率随孔隙率的增大而上升.     

纳米羟基磷灰石/左旋聚乳酸纳米纤维复合支架的制备与表征

采用热致相分离法制备了一系列具有微米级孔隙的纳米纤维状纳米羟基磷灰石/左旋聚乳酸（n-HA/PLLA）复合支架材料。并采用扫描电境和体外降解实验对其进行了表征。扫描电镜观测到复合支架的微观结构为具有微米级孔隙的纳米纤维状骨架,其不规则孔的孔径在几到几百纳米的范围内,纳米纤维直径在200-500nm的范围内;体外降解实验的结果表明,与纯聚乳酸支架相比,n-HA/PLLA复合支架的降解液的pH的变化更加缓慢。     

疏水/亲水性大孔聚二乙烯基苯/聚丙烯酰乙二胺互贯树脂的合成及其孔结构研究

采用分步悬浮聚合法制备的大孔聚二乙烯基苯／聚丙烯酸甲酯互穿聚合物网络（Interpenetrating polymer networks IPN），经过乙二胺氨解，得到新型疏水／亲水性聚二乙烯基苯／聚丙烯酰乙二胺互穿网络（polydivinylbenzene／poly acrylethylenediamine IPN即PDVB／PAEMIPN）．孔结构研究表明，树脂的平均孔径达8．6～136nm．研究了混合致孔剂中良致孔剂与非良致孔剂的比例、两网质量比以及第二网交联度对树脂孔结构的影响．     

离心—冷冻法制备梯度孔结构的真皮支架

胶原基真皮支架的结构和性能受多方面因素影响,比如除胶原外的其他主要材料、支架的孔径和孔隙率以及交联度等.采用离心—冷冻法结合冷冻干燥法制备梯度孔结构的真皮支架,表征支架的孔径和孔隙率,并以细胞培养检验其生物相容性,其中采用扫描电镜对上中下3部分支架结构及孔径进行表征,并通过细胞培养生长实验检测该支架材料的细胞粘附性能,以达到表征离心力的影响.结果显示,离心力对支架的微观结构产生了影响,支架的致密程度从下到上有明显的不同,具体表现在孔径上:上层孔径52±27.8μm,中层孔径57±8.7μm,下层孔径49±40.4μm.同时,细胞粘附实验表明,致密的下层更适合细胞的粘附生长.     

聚乳酸多孔支架的制备研究

分别采用粒子滤出法和冷冻干燥粒子滤出复合法制备了聚乳酸多孔支架.在粒子滤出法中,采用氯化钠和碳酸氢铵作为造孔剂制备多孔支架;在冷冻干燥法中,采用碳酸氢铵和冰颗粒作为造孔剂制备多孔支架.实验结果表明:采用氯化钠或碳酸氢铵做造孔剂,生成的多孔支架有造孔剂残留;采用冰颗粒造孔则无残留.研究认为,采取适当的工艺措施,加速造孔剂向环境的传质过程,是降低支架中造孔剂残留的有效途径,并提出了在实际中可采取的改进措施,包括选用易于滤出的材料、提高氯仿和造孔剂含量、提高温度和真空度、采用特殊气氛、提高过滤溶液的流动性.     

CPP/PLLA软骨组织工程支架复合材料制备及其性能表征

采用溶媒浇铸/粒子滤取技术与气体发泡相结合的方法制备了三维、连通、微孔网状结构的CPP/PLLA软骨组织工程支架复合材料.测试了CPP/PLLA软骨组织工程支架复合材料的物理、力学性能并借助扫描电镜对其微结构进行了观察.结果表明,支架复合材料的初始物理、力学性能和微结构满足软骨组织工程对其支架材料的要求.     

CPP/PLLA软骨组织工程支架复合材料降解性能研究

采用溶媒浇铸/粒子滤取技术与气体发泡相结合的方法制备出CPP/PLLA软骨组织工程支架复合材料,测试了该支架复合材料的物理力学性能和降解性能.研究结果表明,CPP/PLLA软骨组织工程支架复合材料具有适宜的孔隙率,良好的降解性能和物理力学性能,以及三维连通、微孔、网状微观结构.因此,该复合材料有望成为软骨组织工程支架材料之一.     

平板型多孔Al2O3陶瓷载体的研制

通过用固态粒子烧结法制备多孔氧化铝陶瓷,研究了玻璃相物质、有机成孔剂等对多孔陶瓷的孔隙率、孔径、透水率及硬度的影响,制得了具有较高孔隙率（44％－60％）,一定孔径分布及强度的多孔氧化铝陶瓷。     

磷酸和AlCl3含量对介孔Ti-P-Al材料合成的影响

以十六烷基三甲基溴化铵（CTAB）为模板剂、通过后处理法合成了介孔结构的Ti—P—Al材料．此类材料无需焙烧即呈现出典型的介孔特征。采用多种表征手段如XRD、FTIR以及氮气物理吸附等方法考察了磷酸浓度和AlCl3量对所得介孔材料的影响。实验表明：磷酸浓度影响TiP介孔结构的长程有序性．但对介孔Ti—P—A1l料的影响很小。AlCl3量对所得介孔结构的影响非常明显,AlCl3量小时得不到介孔材料而AlCl3量大时样品的长程有序性下降。AlCl3量也影响介孔材料中的模板剂含量：在MTP0.25Aly系列样品中．当y=0．7时样品中的模板剂基本没被脱除,因而得到的是无孔材料;当y=7时样品中的绝大部分模板剂已被脱除而得到了介孔材料,所得样品原粉的比表面积为284m^2/g、孔容（u）为0．38cm^3／g、孔径（D）为3．98nm;进一步增加AlCl3量至y=14时,样品原粉的比表面积高达324m^2/g,孔容和孔径分别为0．39cm^2/g和3．68nm。     

Covalently immobilized gelatin gradients within three-dimensional porous scaffolds

A stable gelatin gradient providing continuous increment of signaling for cell adhesion and proliferation was fabricated within 3D poly（L-lactic acid） （PLLA） scaffolds. The porous PLLA scaffold fabricated by NaCI particle leaching was vertically fixed on a glass vial. 1,6-Hexanediamine/propanol solution was continuously injected into the vial by a micropump to aminolyze the PLLA scaffold. As a result of reaction time difference, the introduced -NH2 groups increased continuously along with the longitude of the PLLA scaffold in the z-direction. After covalent immobilization of gelatin by glutaraldehyde coupling, the gelatin gradient scaffold was thus obtained. In vitro chondrocyte culture showed that the cells had higher viability and more extending morphology in the gelatin gradient scaffold than that in the uniform gelatin control.     

Dexamethasone-Loaded PLGA Microspheres Incorporated PLLA/PLGA/PCL Composite Scaffold for Bone Tissue Engineering

The combination of micro-carriers and polymer scaffolds as promising bone grafts have attracted considerable interest in recent decades.The poly(L-lactic acid)/poly(lactic-co-glycolic acid)/polycaprolactone(PLLA/PLGA/PCL)composite scaffold with porous structure was fabricated by thermally induced phase separation(TIPS).Dexamethasone(DEX)was incorporated into PLGA microspheres and then loaded on the PLLA/PLGA/PCL scaffoldtopreparethedesiredcompositescaffold.The physicochemical properties of the prepared composite scaffold were characterized.The morphology of rat bone marrow mesenchymal stem cells(BMSCs)grown on scaffolds was observed using scanning electron microscope(SEM)and fluorescence microscope.The resultsshowedthatthePLLA/PLGA/PCLscaffoldhad interconnected macropores and biomimetic nanofibrous structure.In addition,DEX can be released from scaffold in a sustained manner.More importantly,DEX loaded composite scaffold can effectively support the proliferation of BMSCs as indicated by fluorescence observation and cell proliferation assay.The results suggested that the prepared PLLA/PLGA/PCL composite scaffold incorporating drug-loaded PLGA microspheres could hold great potential for bone tissue engineering applications.     

Preparation of fiber-microsphere scaffolds for loading bioactive substances in gradient amounts

Gradient scaffolds are needed for interface tissue regeneration. In this study, a technique combining electrospinning and electrospraying was developed for preparing poly(L-lactide-co-glycolide) (PLGA) fiber-microsphere scaffolds for loading bioactive substances in gradient amounts. The gradient fiber-microsphere scaffolds contain two sheets of electrospun membranes and a sheet of microspheres loaded with bioactive substances in gradient amounts between the electrospun membranes. The morphologies of the gradient scaffolds were characterized and bovine serum albumin (BSA) was loaded as a model bioactive substance. The amount of BSA-loaded microspheres decreased gradually along the length of the gradient scaffold. The addition of poly (ethylene glycol) significantly improved the hydrophilicity of the gradient scaffold and the release behavior of BSA with respect to the gradient became apparent, with differences in the release amounts along the length of the gradient scaffold being observed. The biocompatibility of the gradient scaffold was verified using MC3T3-E1 pre-osteoblastic cells. The study demonstrated that the combination of electrospinning and electrospraying was a feasible method for the preparation of gradient scaffolds for potential applications in interface tissue engineering.     

后聚合直接法制备聚L-乳酸的研究

L-乳酸预聚物在SnCl2·2H2O和对甲苯磺酸双催化体系下,用直接法熔融后聚合合成聚乳酸,研究了后聚合反应时间、预聚物相对分子质量等因素对聚合产物的影响,采用核磁及粘度计法测定聚合物相对分子质量,通过红外、核磁、X-射线衍射等手段对聚合物进行了表征及测试,表明在适宜的工艺条件下,熔融后聚合直接法合成较高相对分子质量的聚L-乳酸是可行的.     

Fabrication and characterization of a PAM modified PHBV/BG scaffold

In order to improve the bioactivity and mechanical strength of the scaffold used in bone repair simultaneously, a novel porous PAM-poly （β-hydroxybutyrate-co-β-hydroxyvalerate） （PHBV）/bioactive glass （BG） scaffold was prepared by photo-initiated polymerization. PAM was used to improve the hydrophilicity of PHBV matrix while the BG particles were added to increase the bioactivity and strength of the matrix synchronously. The grafted amide group and Si-O moieties from acrylamide and the added BG were confirmed by Fourier Transform Infrared Spectrometry （FTIR）. The micromorphology of the scaffolds before and after grafting was observed by scanning electron microscopy （SEM）. The resulting images demonstrate that the PAM-PHBV/BG scaffold has a well connected pore structure and appropriate pore size which may be convenient for cells to grow and discharge metabolites. The specific gravity method was used to evaluate the pore property of the scaffold and the result shows that the scaffold has an average porosity up to 82.0%. Mercury intrusion porosimetry （MIP） indicated that the pores of PAM-PHBV/BG scaffold were mainly distributed between 75 and 150 μm. The compressive strength test was adopted to evaluate the mechanical property of the scaffold. The result shows that the PAM-PHBV/BG scaffold has a relatively high compressive strength （0.91 MPa） when compared with the pure PHBV scaffold. Besides, the properties of the pure PHBV scaffold, PHBV/BG scaffold were also evaluated. The newly prepared PAM-PHBV/BG scaffold may be worthy of further studying as a bone repair material.     

基于氮磷废水处理的沸石多孔吸附材料制备

以改性沸石粉体为原料,采用添加黏结剂和造孔剂方法制备多孔颗粒沸石,重点研究了黏结剂种类、用量、造孔剂种类和用量,水添加量等对颗粒沸石散失率及吸附氨氮、磷酸盐性能的影响.结果表明:聚乙烯醇(PVA)黏结效果优于水泥和羧甲基纤维素钠(CMC),造孔剂碳酸氢钠相比较活性炭效果更佳.扫描电镜(SEM)结果发现添加碳酸氢钠后,颗粒沸石孔径增大,孔隙结构得到明显改善.在改性沸石粉体中添加1.2%PVA、4%碳酸氢钠、40%水制备所得颗粒型沸石散失率为0,且具有较高氮磷吸附性能,对水中氨氮、磷酸盐的去除率高达88.55%和83.11%.吸附动力学实验表明,多孔颗粒型沸石对氮磷的吸附更加符合拟二级动力学模型.     

Incorporation of Sphingosine 1-Phosphate Loaded Mesoporous Silica Nanoparticles into Poly( L-lactic acid ) Nanofibrous Scaffolds for Bone Tissue Engineering

Controlled release of the functional factors is the key to improve clinical therapeutic efficacy during the tissue repair and regeneration.The three-dimensional(3D)scaffold can provide not only physical properties such as high strength and porosity but also an optimal environment to enhance tissue regeneration.Sphingosine1-phosphate(S1P),an angiogenic factor,was loaded into mesoporous silica nanoparticles(MSNs)and then incorporated into poly(L-lactic acid)(PLLA)nanofibrous scaffold,which was fabricated by thermally induced phase separation(TIPS)method.The prepared scaffolds were examined by attenuated total reflection Fourier transform infrared spectroscopy(ATR-FTIR),scanning electron microscopy(SEM),and transmission electron microscopy(TEM)and compressive mechanical test.The ATR-FTIR result demonstrated the existence of MSNs in the PLLA nanofibrous scaffold.The SEM images showed that PLLA scaffold had regular pore channel,interconnected pores and nanofibrous structure.The addition of MSNs at appropriate content had no visible effect on the structure of scaffold.The compressive modulus of scaffold containing MSNs was higher than that of the scaffold without MSNs.Furthermore,fluorescein isothiocyanate(FITC)was used as model molecule to investigate the release behavior of S1P from MSNsincorporated PLLA(MSNs/PLLA)nanofibrous scaffold.The result showed that the composite scaffold largely reduced the initial burst release and exhibited prolonged release of FITC than MSNs.Thus,these results indicated that S1P-loaded composite nanofibrous scaffold has potential applications for bone tissue engineering.     

苯基三乙氧基硅烷与氨丙基三乙氧基硅烷的水解共缩聚

研究了苯基三乙氧基硅烷与氨丙基三乙氧基硅烷在甲苯/水/盐酸、四氢呋喃/水/盐酸、乙醇/水/氨、十二烷基硫酸钠/水/四甲基氢氧化铵四个较典型体系中的水解共缩聚,通过界面聚合、溶液聚合、分散聚合、乳液聚合分别得到了树脂状、粒径200nm微球、粒径3μm微球和乳液状的聚氨丙基/苯基倍半硅氧烷,采用元素分析、红外光谱、核磁共振等对各产物的组成、结构、性能等进行了对比分析。结果表明酸催化体系共聚物为溶解性良好的低交联链状结构,乙氧基水解完全,而存在碱催化的体系产物交联度高,溶解性较差,结构中残留未水解的乙氧基; 溶剂的极性对共聚物的溶解、析出、粒子的形成影响较大。     

Fabrication and Properties of Porous Film/Fabric Composites for Vascular Scaffold Application

A composite vascular scaffold combining textile reinforced structure and biodegradable polymer is introduced, which may possess high porosity and connectivity. Moreover, the porous size could be controlled. The proposed scaffold consists of a warp-knitted poly （ethylene terephthalate ） （PET） fabric with well-defined macropores, which is embedded with a porous biodegradable polymer membrane. The aim of this paper is to study the fabrication and properties of porous polymer membrane through optimizing the parameter of composite methods from freeze drying/particle leaching （ FD/PL ） and gas foaming/particle leaching （ GF/PL ）, subsequently combining with the warp-knitted fabric. Weighing method was utilized to analyze the porosity of the samples and the scanning electron microscope （SEM） images were taken to observe the porous structure of the vascular membrane. In addition, ,the static contact angle （CA） was measured to estimate the hydrophilicity of the samples, and the tensile testing of the composites was performed on the universal mechanical tester. Furthermore, the water permeability of the membrane was also calculated. The results showed that the porosity and pore connectivity of the vascular membrane were diverse, became of solution concentration, particle size, ratio of content, etc. Meanwhile, the stress-strain curves and the bursting strength showed the different mechanical properties among composite scaffolds in different structures.