超临界流体技术合成的复合型骨替代生物材料：体内外生物学评价

背景：在复合材料内部增加细胞黏附性较好的高分子材料或同骨组织羟基磷灰石成分相似的无机材料，可以改善材料的表面化学结构。过去的十几年，产生和发展了许多合成生物降解支架材料的新技术，虽然超临界流体技术应用在合成支架中时间尚短，但有着其他技术不可比拟的众多优点，目前越发受到学者的重视。 目的：以聚乳酸和同种异体骨粉为原材料，通过超临界流体技术合成复合型骨替代生物材料，评价其生物学特性。 方法：首先将同种异体皮质骨粉与聚乳酸在超临界二氧化碳作用下合成多孔复合型骨生物替代材料。将材料浸提液与成骨细胞系复合培养，体外观察细胞形态、增殖情况；通过材料浸提液皮内注射实验和材料肌袋内埋入实验，体内观察动物的致敏、组织炎症发生情况。 结果与结论：体外大体观察该种复合材料形状、大小、孔隙可控，孔径适中，有较好的硬度，体外实验表明细胞相容性良好，对细胞的增殖无毒副作用；体内实验表明材料植入动物体内未发生致敏反应，组织相容性良好，但无异位成骨作用。说明制备的新型复合骨组织生物材料在细胞学和生物相容性检测上可以满足组织工程支架和骨组织替代的要求，该种合成技术及多孔生物材料有广阔发展前景。 关键词：聚乳酸；同种异体骨；超临界流体技术；复合材料；组织工程 doi:10.3969/j.issn.1673-8225.2010.25.005

Substitution of biomaterials by a composite bone fabricated by supercritical fluid technique: In vivo and in vitro biological evaluation

BACKGROUND: Polymer based materials can improve surface chemical structure via increasing inside inorganic material. A series of techniques have been produced and developed for synthesizing biodegradable materials, and supercritical fluid technique is a superior one. OBJECTIVE: To substitute biomaterials by a composite bone fabricated by supercritical fluid technique, and to evaluate the biological characteristics of the novel composite biomaterial. METHODS: Granulated allogeneic bone and polymer of lactic acid (PLA) were compounded to fabricate the composite scaffold by the supercritical fluid technique. The composite scaffold was cytological estimated through on osteoblasts line culture. Meanwhile the sensitization and tissue inflammation were observed by animal experiment that the saturation was injected subcutaneously and the scaffold was implanted directly into muscle. RESULTS AND CONCLUSION: The figuration, volume and micro-structure of the scaffold were controllable and the biological characteristics of the novel composite biomaterial were excellent. In vivo test demonstrated that, no sensitization response occurred, but the material had no ability of heterotopic osteogenesis. The results illustrated that the prepared novel composite biomaterial can meet the requirement of cellular compatibility and biocompatibility, which has a broad prospect in future.