骨组织工程纳米复合支架及其生物学评价

目的:综述骨组织工程常用支架材料的种类及其性能,同时,简介一种新型的,可降解的,具有三维空间网络结构的纳米支架材料——细菌纤维素/羟基磷灰石复合材料,并探讨纳米生物材料的安全性评价.资料来源:检索人为第一作者,检索文献时限为1979-01/2009-06,检索数据库为PubMed数据库(http://www.ncbi.nlm.nih.gov/PubMed)及CNKI数据库(www.cnki.net/index.htm).中文检索词"骨组织工程,细菌纤维素,安全性评价";英文检索词为"bone tissue engineering,Bacterial cellulose,safety evaluation".资料选择:①文章所述内容与骨组织工程密切相关.②有关于纳米材料安全性评价的文章.结局评价指标:骨组织工程材料的种类及性能,纳米材料的安全性.结果:常用的3种支架材料有天然生物材料,人工合成高分子生物材料及陶瓷材料.单一材料难以满足组织工程所需的机械强度和生物相容性,而生理状态的磷灰石是纳米级,纳米级复合材料更符合仿生的原则.细菌纤维素与具有极好生物活性、骨传导作用和骨结合能力的纳米羟基磷灰石复合制成纤维状复合支架材料,不仅具有足够的强度,还具有骨传导功能,以满足骨细胞在支架上的黏附和繁殖,成为一种很有前途的骨组织工程纳米支架材料.对生物材料生物相容性的研究与评价,不仅要从整体水平去观察材料对人体各系统的影响,从细胞水平去观察材料对细胞的数量、形态及分化的影响,还要深入到分子水平去观察材料对细胞DNA、mRNA以及蛋白表达水平的影响.结论:由于细菌纤维素,羟基磷灰石复合支架材料结合细菌纤维素和羟基磷灰石两种材料的优点,其复合产物的性能将优于传统的骨组织工程产品.对其完成一系列生物相容性评价后,新一代骨组织工程三维纳米纤维仿生支架材料便可安全的投入到临床应用.

Biological evaluation of bone tissue-engineered nanocomposite scaffold

OBJECTIVE: To summarize types and performances of bone tissue-engineered scaffold materials, abstract a new nanocomposite scaffold, i.e., bacterial cellulose/hydroxyapatite composite, characterizing by degradable and three-dimensional network structure, and to evaluate the safety of nano-materials. DATA SOURCE: A computer-based online search was conducted in PUMMED (http://www.ncbi.nlm.nih.gov/PubMed) and CNKI (www.cnki.net/index.htm) with the key words of "bone tissue engineering, bacterial cellulose, safety evaluation" in both Chinese and English from January 1979 to June 2009. DATA SELECTION: The articles which were correlated with bone tissue engineering and safety evaluation of nano-materials were included. MAIN OUTCOME MEASURES: Types and performances of bone tissue-engineering materials and safety of nano-materials. RESULTS: Three scaffold materials were always used including nature biomaterial, artificial polymer biomaterial, and ceramic material. Single material did not meet the requirement of mechanical strength and biocompatibility; however, apatite was a nano-grade, which coincided with the bionics principle. Bacterial cellulose/hydroxyapatite composite was characterized by great intension and bone conduction which were required by adhesion and proliferation of bone cells on the scaffold. Therefore, bacterial cellulose/hydroxyapatite composite became a new nano-scaffold material for bone tissue engineering. Biocompatibility was studied and evaluated by the effects of biomaterials on human body system, cell number, morphology, and differentiation, as well as DNA, mRNA and protein expression. CONCLUSION: Performance of bacterial cellulose/hydroxyapatite composite is superior to traditional bone tissue-engineered materials. When the biocompatibility was evaluated completely, the new three-dimensional bone tissue-engineered nano-fiber scaffold materials are safe for the clinical application.