In vitro characterization of PBLG-g-HA/ PLLA nanocomposite scaffolds

The purpose of the present study was to synthesize a new composites scaffold containing poly(γ-benzyl-L-glutamate) modified hydroxyapatite/(poly(L-lactic acid))(PBLG-g-HA/PLLA) and to investigate their in vitro behaviour on bone mesenchymal stromal cells(BMSCs). The results demonstrated that BMSC proliferation was signifi cantly increased on PBLG-g-HA/PLLA scaffolds after 3 and 7 days post seeding when compared to PLLA and HA/PLLA scaffolds. The in vitro osteogenic differentiation also favoured the composite PBLG-g-HA/PLLA scaffolds when compared to controls by signifi cantly increasing Runx2, ALP or osteocalcin mRNA expression as assessed by real-time PCR. The results illustrate the potential of PBLG-g-HA/PLLA scaffolds for bone tissue engineering applications. And the in vivo testing further confi rms the PBLG-gHA/PLLA scaffolds' potentioal for healing critical bone defects.     

Periodontal ligament cells cultured on the tricalcium phosphate/chitosan scaffolds in vivo and in vitro

To search suitable scaffolds for periodontal tissue regeneration, different ratios of tricalcium phosphate/chitosan(TCP/chitosan) scaffolds were prepared through a freeze-drying process. Human periodontal ligament cells(HPLCs) were incubated on the scaffolds in vitro. Cells were cultured on the scaffolds, detected by scanning electron microscopy (SEM). HPLCs were analyzed by MTT assay and alkaline phosphatase(ALP) activity detection. HPLCs were seeded onto the scaffolds. Then these scaffolds with HPLCs were implanted subcutaneously into athymic mice. The state of periodontal tissue regeneration was detected after 4 weeks. As the ratio of TCP increased, TCP/chitosan scaffolds accelerated HPLCs proliferation significantly higher than the pure chitosan scaffold. HPLCs produced the cementoid tissue in vivo. The periodontal tissue regeneration engineering is able to be applied with TCP/chitosan scaffolds.     

BCP/COL/HCA骨组织工程支架的仿生制备

通过仿生合成、冷冻干燥及交联处理方法,制备出一种以双相磷酸钙、胶原和碳酸羟基磷灰石三组分为主要成分的新型三维骨组织工程支架。采用SEM、EDX和FTIR等测试技术对支架的性能特征进行分析。结果表明：制备的复合支架具有三维多孔的有序结构。双相磷酸钙作为力学支撑骨架有助于胶原网络基质形成特定的形状并使之具有一定的力学强度。在矿化过程中,羟基磷灰石矿物晶体在胶原的反应成核位点通过化学键合作用进行自组装。交联的胶原及其仿生矿化形成的碳酸羟基磷灰石可使支架具有良好的生物学性能,有望成为广阔临床应用前景的骨组织工程植入材料。     

多元羟基磷灰石纳米生物复合材料研究进展

本文综述了羟基磷灰石基纳米生物复合材料研究进展,总结分析羟基磷灰石与壳聚糖、明胶、聚酰胺等组分的二元生物复合材料,以及羟基磷灰石-壳聚糖-明胶、羟基磷灰石-壳聚糖-聚酰胺等三元生物复合材料的制备方法、组织结构特征和相关性能。     

In vitro Mineralization Behavior of the Sol-gel Derived Bioglass/Collegen Composite Porous Scaffold

1Introduction Thesol gelderivedbioactiveglassesinthesystem CaO P2O5SiO2arenewgenerationofbioglasses.The studieshaveindicatedthatthesol gelderivedbioglasses possesshigherbioactivity,homogeneityandstabilityof compositionthanthoseofthemeltderivedbioglasses[17].Inaddition,asanewtechniquetodevelopbiomaterials,sol gelmethodisrelativelyconvenienttopreparebioactive coatings,fibersandfinepowders.Thepreparationofthe sol gelbioglassescanbeconductedatroomtemperature firstly,thenheat treatedattemperatur…     

In vitro biocompatibility assessment of a novel PRGD/PDLLA/NGF composite material

The objective of this study was to evaluate the degradability and biocompatibility of a novel composite materials which was grafted with RGD and immobilized with NGF(PRGD/PDLLA/NGF). The releasing of NGF, the biodegradability and cell-biocompatibility of PRGD/PDLLA/NGF membrane were evaluated in vitro. The experimental results showed that the NGF release process was prolonged over 30 days. Furthermore, the PRGD/PDLLA/NGF showed a better hydrophilicity, better biodegradation properties and cells affinity than PDLLA, which means a good support to adhesion and proliferate of Schwann cells. Therefore, the novel composite material holds considerable promise as scaffolds in nerve tissue engineering.     

壳聚糖基骨组织工程支架材料的研究进展

壳聚糖是甲壳素脱乙酰基的产物,是第二大天然高分子,由于其良好的生物相容性、生物可降解性和成型性,作为骨组织工程支架材料越来越受到重视.对壳聚糖为主的复合骨组织工程支架的相关研究进行综述,可以掌握其在不同的材料体系中的功能作用,并可预见壳聚糖基生物材料在骨组织工程中的发展潜力.     

Preparation and characterization of nano-hydroxy apatite/konjac glucomannan composite scaffolds

A novel nano-hydroxyapatite (HA)/konjac glucomannan composite scaffold with high porosity was developed by blending nano-HA particles with konjac glucomannan in alkaline solution. The scanning electron microscopy, porosity measurement, X-ray diffraction(XRD), and Fourier transformed infrared(FTIR) spectroscopy were used to analyze the physical and chemical properties of the composite scaffolds. The pure konjac glucomannan scaffolds and composite scaffolds were similar in their macroscopic morphology, however, the microscopic morphology on porewall surfaces was quite different. The diffraction patterns of XRD revealed the presence of konjac glucomannan and HA in the composite scaffolds. In addition, the results of FTIR also showed the existence of the functional group of HA. These results reveal that the newly developed nano-HA/konjac glucomannan composite scaffold may serve as a good three-dimensional substrate in bone tissue engineering.     

微硅粉/聚丙烯复合材料制备与表征

低温煅烧微硅粉并用硅烷偶联剂Si69对其进行改性,再分别将未改性和改性微硅粉作为无机填料与聚丙烯混合后制备复合材料。未改性微硅粉掺入量为复合材料总质量的2%,改性微硅粉掺入量分别为总质量的1%、2%、3%、4%及5%,并分别在155℃、168℃、175℃温度下制备试样。测试各试样的拉伸强度、断裂伸长率、弯曲强度、冲击强度,观察其断裂面的形貌,并进行红外检测,研究改性微硅粉在不同掺量下对聚丙烯性能的影响。结果表明:改性微硅粉占复合材料质量分数的2%时复合材料的拉伸强度、弯曲强度及冲击强度得到改善;未改性或改性微硅粉加入量大于4%时会降低以上强度;用热压成型制备试样时,温度高于168℃即可成型良好。     

PMMA/SiO_2复合颗粒制备与表征

乳液聚合是对纳米颗粒改性的常用方法,但聚合效果不好且对改善纳米颗粒的分散作用不大。本实验引入硅烷自组装单分子层,采用无皂微乳液聚合法制备PMMA/SiO2复合颗粒。EDS、FTIR、TEM、LSS分析表明,纳米SiO2通过硅烷功能化,可以更有效地与MMA发生化学键合。复合颗粒在水中分散效果明显改善,不规则形状纳米SiO2通过组装而接近球形结构。复合颗粒具有很好的有机相容性和分散稳定性。     

In Vitro Biomineralization of Glutaraldehyde Crosslinked Chitosan Films

The biomimetic approach was applied to study the in vitro biomineralization of series of the chitosan films crosslinked ty glutaraldehyde. The deposited calcium phosphate comings were studied using scanning electron microscopy and energy dispersive X-ray analysis. Initially, the treatment in simulated body fluid (SBF) results in the formation of single layer of calcium phosphate particles over the film surface. As immersion time in SBF increases, further nucleation and growth produce a simulated calcium phosphate coating. The Ca/P molar ratio of the calcium phosphate increases with the immersion time, showing a rapid formation of calcium-deficient phosphate material from the phase of octac 1 alcium phosphate. The different glutaraldehyde crosslinking degree influeaces the morphology and magnitude of the calcium phosphate coatings on the surface of the chitosan films.     

In vitro biomineralization of glutaraldehyde crosslinked chitosan/glutamic acid films

In vitro biomineralization of glutaraldehyde crosslinked chitosan/glutamic acid films were studied. IR and ESCA (electron spectroscopy for chemical analysis) determinations confirm that chitosan and glutamic acid are successfully crosslinked by glutaraldehyde to form chitosan-glutamic acid surfaces. Composite films were soaked in saturated Ca(OH)₂ solution for 8 d and then immersed in simulated body fluid (SBF) for more than 20 d. Morphological characterizations and structure of calcium phosphate coatings deposited on the films were studied by SEM, XRD, and EDAX (energy dispersive X-ray analysis). Initially, the treatment in SBF results in the formation of single-layer calcium phosphate particles over the film surface. As immersion time increases, further nucleation and growth produce the simulated calcium-carbonate hydroxyapatite coating. ICP results show Ca/P ratio of calcium phosphate coating is a function of SBF immersion time. The inducing of glutamic acid improves the biomineralization property of chitosan films. Funded by the Natural Science Foundation of Shanghai (No. 04ZR14087)     

Preparation and Characterization of Nanosized Hydroxyapatite Particles in AOT Inverse Microemulsion

1　IntroductionSynthetichydroxyapatite (HAP) ,whichisthemajorconstitutionofnaturalboneandteeth ,iswell knownasbiocompatibleandbioactivematerialthathasbeenwidelyusedinmanyclinicalapplications[1 3] .Forexample ,po roushydroxyapatitehasbeenusedinbone ingrow…     

Synthesis and Characterization of Core-shell Hydroxyapatite/chitosan Biocomposite Nanospheres

Novel core-shell hydroxyapatite/chitosan biocomposite nanospheres were synthesized in a multiple emulsion. The multiple emulsion was a w/o/w emulsion, made of diammonium phosphate solution as an inner aqueous phase, cyclohexane as an oil phase, and calcium nitrate solution and chitosan solution as an outer aqueous. The forming mechanism of core-shell spheres and the influence of temperature on the morphology of the nanospheres were investigated. The diameter of the resulting core-shell nanospheres was 100-2...     

A new multifunctional polymer: Synthesis and characterization of mPEG-b-PAA-grafted chitosan copolymer

A new multifunctional mPEG-b-PAA-grafted chitosan copolymer possessing amino and carboxyl groups, mPEG-b-PAA-g-CHI (compound 6), was designed for a potential application in gene/drug delivery and synthesized by the methods of reversible addition-fragmentation chain transfer (RAFT) polymerization of acrylic acid (AA) and grafting reaction of a biodegradable chitosan (CHI) derivative. Completion of the reactions and characterization of the resulting compounds were demonstrated by ¹H NMR, FTIR and gel permeation chtomatography (GPC) studies. The results show that the molar ratio of amino groups to carboxyl groups in the copolymer (compound 6) is 0.41:0.59.     

Effects of Antihepatocarcinoma with Apatite Nanoparticles in vivo

The inhibition effect of hydroxyapatite （ HAP ） nanoparticles on hepatocarcinoma was investigated in vivo. The human hepatocarcinoma cell line Bel- 7402 was transplanted subcutaneously into nude mice. Hydroxyapatite nanoparticles suspension at a dose of 0. 2 mL was injected into the transplanted tumors every day for 2 weeks, and saline was used us control. The efficacy of hydroxyapatite nanoparticles on this carcinoma was surveyed and morphological changes of tissue and cells were observed by light microscopy and transmission electron microscopy （TEM）. Experimental results show that hydroxyapatite nanoparticles have a visible destructive effect on the structures of hepatocarcinoma cells and tissue. The inhibition rates of tumor growth were 77.21% and 51. 32% after intra-tumor injection of hydroxyapatite nanoparticles for 1 week and 2 weeks, respectively. Compared with the control group, hydroxyapatite nanoparticles can also prolong the survival time of the nude mice bearing this cancer significantly. This indicates that hydroxyapatite nanoparticles have the therapeutic potential on hepatoma in vivo.     

AW玻璃基骨水泥的制备及其结构性能表征

以AW生物玻璃与柠檬酸/磷酸氢钾复合固化液混合制得玻璃基生物骨水泥(GBC),利用XRD、FTIR和SEM对GBC的产物晶相、化学组成和显微结构进行了分析,并对其力学性能进行了测试。结果表明,GBC在固化反应后就已经有羟基磷灰石(HA)晶相生成;随着GBC在SBF中浸泡时间的延长,又生成了少量碳酸钙晶体,且HA晶相数量增多,抗压强度在7 d时达到最大值,骨水泥呈现多孔结构。     

壳聚糖/羧甲基壳聚糖止血膜的制备与表征

针对壳聚糖止血膜柔韧性差的问题,以丙三醇和酚磺乙胺作为改性剂,采用溶液浇膜的方法制备了不同组成配比的壳聚糖(CS)/羧甲基壳聚糖(CMCS)止血膜,并评价了CS/CMCS止血膜拉伸性能和止血效果.丙三醇的引入可使CS/CMCS止血膜的断裂伸长率提高4~7倍,尽管其拉伸强度也降低了70%.丙三醇改性的CS/CMCS=8/2载药止血膜具有较好的拉伸强度(10.4±0.9 MPa)和断裂伸长率(50.4±4.5%);与未加入酚磺乙胺的CS/CMCS止血膜相比,酚磺乙胺的离子交联作用使CS/CMCS载药止血膜的拉伸强度提高55%,而断裂伸长率仅降低24%.止血评价结果表明经丙三醇改性的CS/CMCS=8/2止血膜均能使血液发生分离的时间明显缩短,并具有促使血液凝结形成黑色血块的能力.     

AW玻璃基骨水泥的制备及其结构性能表征

以AW生物玻璃与柠檬酸／磷酸氢钾复合固化液混合制得玻璃基生物骨水泥（GBC）,利用XRD、FTIR和SEM对GBC的产物晶相、化学组成和显微结构进行了分析,并对其力学性能进行了测试。结果表明,GBC在固化反应后就已经有羟基磷灰石（HA）晶相生成;随着GBC在SBF中浸泡时间的延长,又生成了少量碳酸钙晶体,且HA晶相数量增多,抗压强度在7d时达到最大值,骨水泥呈现多孔结构。     

一种胶原支架材料的结构与性能表征

针对脱细胞真皮基质(acellular dermal matrix, ADM)孔径小、孔隙率低、孔隙的连通性不理想的难题,以猪中厚皮为原料,综合碱处理、酶处理、去污剂处理和盐处理手段制备了一种支架材料,通过H＆E染色、红外与紫外可见光谱、扫描电子显微镜、拉力试验、MTT法等手段分析了支架材料的性能。结果显示:支架材料维持了胶原的天然结构,不含细胞成分,紫外与红外吸收符合胶原蛋白的吸收特征,胶原质量分数为(83.19±0.24)％,为具有连通孔道的三维网络结构,孔径约100μm,孔隙率为(76.94±1.08)％,极限抗拉强度为(4.43±0.10)MPa,拉伸弹性模量为(36.08±1.52)MPa,小鼠L929成纤维细胞在其上增殖良好。