多孔碳酸化羟基磷灰石骨水泥的生物相容性研究

目的探讨一种新型的代骨材料--多孔碳酸化羟基磷灰石骨水泥的组织相容性.方法合成碳酸化羟基磷灰石骨水泥,添加成孔剂,制备能原位固化形成多孔结构的碳酸化羟基磷灰石代骨材料,并通过细胞毒性实验和肌内埋植实验检测其组织相容性.结果多孔碳酸化羟基磷灰石骨水泥的浸提液对骨髓基质细胞的生长无影响.细胞于材料表面的生长速度、形态与空白对照组无差别.肌内植入实验发现,材料周围纤维组织包膜的最大厚度为22.5μm,未发现炎性细胞反应.结论多孔碳酸化羟基磷灰石骨水泥具有良好的组织相容性,材料测试结果符合和标准.     

血管内皮生长因子受体在鼠横纹肌的表达与羟基磷灰石/碳纳米管复合材料毒性研究

目的 从观察鼠骨骼肌组织形态学改变和VEGF表达的角度研究CNTs/HAP纳微米复合材料对鼠骨骼肌的细胞毒性。方法 将CNTs/HAP纳米复合材料植入实验鼠臀大肌。按不同时间取材，做组织学观察和RT-PCR分析。结果 1d、3d显微镜下观察，炎细胞和淋巴细胞浸润伴轻度水肿、间质疏松；5d、7d显微镜下观察血管壁增厚，单核巨噬细胞和纤维组织增生，少量肌纤维出现变性，VEGF表达呈上升趋势；14天显微镜下观察周围组织间质血管扩张，仅有少量炎细胞浸润，水肿不明显，VEGF表达呈下降趋势。结论 CNTs/HAP对鼠骨骼肌细胞无毒性，有利于血管的再生，具有良好的生物相容性。     

碳酸化羟基磷灰石水泥修复骨缺损的实验研究

目的通过动物实验观察一种新型的骨修复材料———碳酸化羟基磷灰石水泥修复骨缺损的效果。方法在10只杂种犬肱骨近端制作骨缺损动物模型,采用碳酸化羟基磷灰石水泥修复骨缺损,并以高温烧结羟基磷灰石陶瓷作为对照,分别于术后5天、4周、8周、12周和16周处死动物,通过X线和组织学观察其修复效果。结果碳酸化羟基磷灰石水泥完全充填骨缺损,界面与骨结合紧密,生物相容性良好,并且随着植入时间的延长可逐渐降解并被新生骨爬行替代,与骨整合为一体。而羟基磷灰石陶瓷不能紧密充填骨缺损,在实验期间与骨界面清晰,并且没有见到降解现象。结论碳酸化羟基磷灰石水泥具有原位固化性能,是一种较为理想的新型骨缺损修复材料。     

羟基磷灰石在口腔保健领域的应用

本文通过分析羟基磷灰石的生物活性和作用原理,结合龋齿等口腔疾病的发生原因,对这种生物活性材料在预防龋齿、炎症、溃疡和牙齿美白等口腔保健领域中的应用做一综述。     

溶胶-凝胶法制备纳米羟基磷灰石粉体的研究进展

目的 利用溶胶凝胶法制备纳米羟基磷灰石粉体的方法进行研究。方法综述了溶胶凝胶法的基本原理和分类，介绍了制备纳米羟基磷灰石粉体采用的溶胶-凝胶方法，提出了相关待解决的问题。结果溶胶-凝胶法的研究已取得一定的进展。结论利用该方法有望制备出形状可控、粒度均匀的纳米羟基磷灰石粉体。     

In vitro evaluation of electrospun silk fibroin/nano-hydroxyapatite/BMP-2 scaffolds for bone regeneration

Bone tissue engineering by using osteoinductive scaffolds seeded with stem cells to promote bone extracellular matrix (ECM) production and remodeling has evolved into a promising approach for bone repair and regeneration. In order to mimic the ECM of bone tissue structurally and compositionally, nanofibrous silk fibroin (SF) scaffolds containing hydroxyapatite (HAP) nanoparticles and bone morphogenetic protein 2 (BMP-2) were fabricated in this study using electrospinning technique. The microstructure, mechanical property, biocompatibility, and osteogenic characteristics were examined. It was found that the HAP nanoparticles were successfully incorporated in the SF nanofibers (diameter, 200–500 nm). The mechanical properties of SF/HAP/BMP-2 composite scaffolds increased with HAP content when it was less than 20 wt%, after which the mechanical properties dropped as HAP content increased. Cell culture tests using bone marrow mesenchymal stem cells (BMSCs) showed that the scaffolds had good biocompatibility and promoted the osteogenic differentiation of BMSCs. Therefore, the electrospun SF/HAP/BMP-2 scaffolds may serve as a promising biomaterial for bone tissue engineering.     

可注射性纳米羟基磷灰石、壳聚糖复合材料修复骨缺损的实验研究

目的：观察可注射性羟基磷灰石/壳聚糖复合材料对兔桡骨骨缺损修复效果。方法：18只新西兰白兔双侧桡骨中段建立长度为10mm节段性缺损,将可注射性纳米羟基磷灰石/壳聚糖复合材料植入一侧骨缺损作为实验组,另一侧植入单纯羟基磷灰石材料作为对照组,于第4、8、12周末,分别行大体、X线检查、组织学、电镜检测,观察该材料对骨缺损的修复效果。结果：①大体观察、X线检查提示：实验组骨痂生长良好,骨缺损完全修复,对照组骨缺损部分修复,部分骨皮质不连续。②组织形态学: 术后12周,实验组新生骨皮质连接完整,髓腔完全再通;对照组少量新生骨形成,部分纤维组织填充③电镜检查:12周实验组材料基本降解,被新生骨组织替代。结论：可注射性纳米羟基磷灰石/壳聚糖复合材料骨缺损修复能力较单纯羟基磷灰石好,具有确实的骨缺损修复能力。     

Mechanical and biological properties of photocurable oligolactide-HA composites investigated under accelerated degradation

The major concern related to biodegradable bone substitute materials is the loss of mechanical strength which can be undesirable when occurring too quickly before new bone formation. In this study, the multifunctional lactide oligomers having 2, 3, and 4 arms end capped with methacrylate groups were synthesized with the aim of improving the degradation properties. Their composites with hydroxyapatite (HA) were photopolymerized and subjected to accelerated degradation at 60 °C. The results showed that increasing number of arms significantly improved thermal and mechanical properties as well as biocompatibility of the composites. All composites although varying in number of arms had similar levels of bone-specific gene expression and calcification indicating their equal bioactivity in supporting bone formation. The high HA content in the composites was proposed to be responsible for enhanced osteoblast response, and this tended to suppress the effects of polymeric structure.