有機改質奈米矽片銀與聚碳酸酯型聚胺酯複合材料之抗菌性、生物相容性與微結構研究

Abstract

奈米銀有良好的抗菌性，但其抗菌效果及可能之細胞毒性受尺寸及分散性影響，且難以分散於疏水高分子中。本研究使用有機改質奈米矽片銀，為蒙脫土脫層之奈米矽片表面以界面活性劑改質，再以此複合物作為載體將銀離子還原其中而製備。具有分散在有機相的能力。本研究先評估有機改質奈米矽片銀的生物相容性及抗菌性，發現在總濃度10 ppm時對大腸桿菌有良好殺菌效果，且無顯著之細胞毒性或免疫反應。本研究隨即合成不同軟硬鏈節比例的聚碳酸酯型聚胺酯，並於篩選其性質後，使用高低軟鏈節比例之聚碳酸酯型聚胺酯進一步混摻有機改質奈米矽片銀形成奈米複合材料，發現軟硬鏈節比例會影響矽片銀在混摻後的效果如物化性質及微相分離程度的變化，而小角度X光數據分析也顯示此一微結構變化的趨勢。在奈米複合材料的生物相容性及抗菌性方面，混摻含75 ppm銀濃度之有機改質奈米矽片銀可大幅改善聚碳酸酯型聚胺酯的抗菌性，無顯著之免疫反應，且細胞相容性及生物穩定性較商用生醫級聚醚型聚胺酯為佳。

Silver nanoparticles (AgNPs) are known for their excellent antimicrobial ability. The antimicrobial ability and the possible induced cytotoxicity of AgNPs depend on particle size and dispersibility. AgNPs are not readily dispersed in most hydrophobic polymers. In this study, an organically modified delaminated clay, in the form of surfactant-capped nanosilicate platelets (“NSQ”), was used to immobilize AgNPs from reduction of silver ion. The nanohybrids of AgNPs and NSQ (“AgNP/NSQ”) provided the possibility of dispersing AgNPs into hydrophobic polymers. AgNP/NSQ in aqueous solution had remarkable bactericidal effect and negligible cytotoxicity and immune response at the overall concentration of 10 ppm. To select model polymers for AgNP/NSQ doping, poly(carbonate)urethane (PCU) with different stoichiometric ratios of hard and soft segments were synthesized. The effect of doing on the physico-chemical properties and microphase separation of the PCU-AgNP/NSQ nanocomposites was determined by the hard/soft segment ratio. The change of microstructure upon doing was confirmed by small-angle X-ray scattering experiments. PCU-AgNP/NSQ nanocomposites containing 75 ppm AgNPs demonstrated superior microbiostatic ability as well as lower immune response and better endothelial cell compatibility and biodurability, compared with the commercial biomedical poly(ether)urethane, Pellethane 2363-80A.