Change in Shape and Crystal Structure of HAP Nanoparticles during Absorption into Cell

The change of hydroxyapatite （HAP） nanoparticles in shape and crystal structure after endocytosis into cancer cells was studied. BEL7402 cells were incubated with HAP nanoparticles for 2 hour, 8 hours, 20 hours, respectively. Then, the cells were collected and viewed under a transmission electronic microscope （TEM）. Electronic diffraction （ED） attached to TEM was used to detect the properties of the particles. The results show that HAP particles in the cytoplasm can be degraded in cytoplasm. The degradation process is prolonged by more than 20 hours. Thus, it is concluded that HAP nanoparticles would be degraded after kill cells or delivery gene.     

Investigation of HAP Nanoparticles Absorbed by Hepatoma Cells in vitro

Many particles are found in the cytoplasm area after the mixture of hydroxyapatite(HAP) nanoparticles and cultured cancer cells.The purpose of this study was to confirm whether these particles in cytoplasm are HAP nanoparticles exactly.BEL7402 cells were incubated in HAP sol for 8 hours.Then,the cells were collected for specimen preparation.Transmission electron microscope(TEM),energy dispersing spectrum (EDS)and electronic diffraction(ED)attached to TEM were used to detect the properties of the particles.It is found that many particles similar to HAP in shape are in the cytoplasm under TEM.By EDS analysis,they are the particles containing calcium(Ca)and phosphorus(P).The classic rings of HAP crystal appear in the ED pictures of these particles.So the particles are confirmed as HAP nanoparticles.Thus,it is concluded that HAP nanoparticles as the crystal particles can be absorbed by hepatoma cells.     

在非水溶液体系中电泳沉积Ti6Al4V/BG/HA梯度涂层

本工作的目的是探索制备钛合金表面生物活性梯度涂层的新方法 ,提高涂层的结合强度及稳定性 .通过诱导羟基磷灰石 (HA)在生物玻璃 (BG)颗粒表面的结晶 ,改变了生物玻璃表面的带电特性 ;采用电泳沉积 (EPD)法 ,在非水溶液体系中实现了BG和HA在阴极Ti6Al4V基体上的共沉积 ,经烧结获得了生物活性梯度陶瓷涂层 ,得到了一种制备生物活性梯度陶瓷涂层的新工艺 .用XRD对涂层的相组成进行了定性分析 ,结果表明涂层由HA ,榍石和玻璃组成 ;采用粘结拉伸法测定的涂层与基体结合强度大于 18MPa,用SEM观察涂层表面及断面的形貌 ,可见涂层表面较为平整 ,没有明显的裂纹 ;涂层与基体结合紧密 ,且存在一明显的界面梯度区域 .     

碳纤维增强α-TCP/TTCP骨水泥的研究

制备了经过氧化处理的碳纤维增强磷酸钙骨水泥(α—tricalcium phosphate cement／tetracalcium phosphate，α—TCP／TTCP)，初步探讨了碳纤维长径比、含量对硬化体抗压、抗折强度的影响．实验结果表明长径比为375，添加量为0．3wt％时，增强效果最为理想，抗压强度提高了55％(最大为63．46MPa)，抗折强度提高近100％(最大为11．95MPa)，而掺入量太大及长径比太高，碳纤维因不能均匀分散将限制其性能的发挥．生物学评价实验结果表明碳纤维增强的骨水泥具有良好的生物相容性。     

碳纤维增强alpha-TCP/TTCP骨水泥的研究

制备了经过氧化处理的碳纤维增强磷酸钙骨水泥(a-tricalcium phosphate cement/tetracalcium phosphate, a-CP/TTCP), 初步探讨了碳纤维长径比、含量对硬化体抗压、抗折强度的影响.实验结果表明长径比为375, 添加量为0.3wt%时, 增强效果最为理想, 抗压强度提高了55%(最大为63.46MPa), 抗折强度提高近100%(最大为11.95MPa), 而掺入量太大及长径比太高, 碳纤维因不能均匀分散将限制其性能的发挥.生物学评价实验结果表明碳纤维增强的骨水泥具有良好的生物相容性.     

可吸收 HA/PDLLA 内固定材料组织相容性观察

可吸收骨折内固定材料要求具有很好的组织相容性。本文将自行研制的可吸收羟基磷灰石／聚ＤＬ乳酸（ＨＡ／ＰＤＬＬＡ）内固定材料植入兔肌肉和骨组织中,于３、６、１２、２４、３６、５２周取材,作ｘ线摄片和组织学观察。结果：骨折在６周内正常愈合,５２周内组织反应较轻,无大量炎性细胞集聚。结论：ＨＡ／ＰＤＬＬＡ复合材料具有很好的组织相容性。     

相分离/糖球沥滤复合法制备聚乳酸多孔支架

支架材料在组织工程修复中起着重要作用,多孔支架材料能为细胞吸附、增殖、分化和最终神经组织的再生提供可靠的环境。因此,采用了一种新的相分离/糖球沥滤复合法制备出聚乳酸(PLA)多孔支架材料,通过扫描电镜对其进行了表征,并计算了支架的孔隙率。研究结果表明,此复合法制备的PLA支架具有高孔隙率、宏观孔相互连通、纳米微孔状孔壁结构,由于其多孔连通且孔径大小可控等优点,适用于各种组织工程应用领域。     

材料生热效应基础研究和作用机理的探讨

根据各种需要,要求材料在各种特定的环境温度下发生变化,产生热效应。根据材料的发热机理和生热条件的不同,经常利用的生热条件是吸收微波生热和在交变磁场作用下的磁致生热。本文综述了两种生热条件下材料热效应的研究现状和发展情况。     

生物可降解高分子材料在医学领域的应用(Ⅰ)──生物可降解高分子材料

生物可降解高分子材料的研究是生物医用高分子研究中最活跃的领域之一,已广泛用于外科手术缝合线,植入体材料及药物释放载体等。本文综述了天然及合成生物可降解高分子材料的研究进展。