Peluso G, Petillo O, Ranieri M, Santin M, Ambrosio L, Calabró D, Avallone B, Balsamo G
Institute of Protein Biochemistry and Enzymology, CNB, Naples, Italy.
Biomaterials. 1994 Dec;15(15):1215-20. doi: 10.1016/0142-9612(94)90272-0.
According to the modern definition of biocompatibility, a biocompatible material need not be inert but be bioactive. A benign reactivity implies that the reactivity has to be appropriate for the intended use. Chitosan, a non-acetylated or partially deacetylated chitin (a linear homopolymer of beta (1-4)-linked N-acetylglucosamine) has been proposed as a biomaterial because of its apparent satisfactory biocompatibility. The present investigation demonstrates that chitosan has an in vitro stimulatory effect on both macrophage nitric oxide (NO) production and chemotaxis. The macrophage NO secretion is attributed to the N-acetylglucosamine unit of the chitosan molecule rather than to the glucosamine residue (28 and 15 microM NO respectively). Moreover, the immune stimulatory effect of chitosan was very specific since other glycosaminoglycans, such as N-acetyl-D-mannosamine and N-acetyl-D-galactosamine, had no effects on NO production (5 and 8 respectively). In vivo experiments strengthen this hypothesis. Transmission electron microscopy analysis identifies the presence of many leucocytes in the specimens after 14 d post-implantation, showing poor healing processes (i.e. fibroblast proliferation and collagen deposition) that characterize the tissue repair at this time in our animal model.
根据生物相容性的现代定义，生物相容性材料不一定是惰性的，而可以是生物活性的。良性反应意味着这种反应必须适合预期用途。壳聚糖是一种非乙酰化或部分脱乙酰化的几丁质（一种由β(1-4)连接的N-乙酰葡糖胺组成的线性均聚物），因其明显令人满意的生物相容性而被提议作为一种生物材料。本研究表明，壳聚糖对巨噬细胞一氧化氮（NO）的产生和趋化性均具有体外刺激作用。巨噬细胞NO的分泌归因于壳聚糖分子的N-乙酰葡糖胺单元，而非葡糖胺残基（分别为28和15微摩尔NO）。此外，壳聚糖的免疫刺激作用非常具有特异性，因为其他糖胺聚糖，如N-乙酰-D-甘露糖胺和N-乙酰-D-半乳糖胺，对NO的产生没有影响（分别为5和8）。体内实验强化了这一假设。透射电子显微镜分析表明，植入后14天标本中存在许多白细胞，显示出愈合过程不佳（即成纤维细胞增殖和胶原蛋白沉积），这是我们动物模型中此时组织修复的特征。
