CReST, Chemical Engineering Division, National Chemical Laboratory, Dr. Homi Bhabha Road, Pune 411008, India.
Langmuir. 2011 Oct 4;27(19):12124-33. doi: 10.1021/la202036c. Epub 2011 Sep 12.
Polypeptide-coated silica nanoparticles represent an interesting class of organic-inorganic hybrids since the ordered secondary structure of the polypeptide grafts imparts functional properties to these nanoparticles. The synthesis of a poly-l-glutamic acid (PLGA) silica nanoparticle hybrid by employing N-carboxyanhydride (NCA) polymerization to synthesize the polypeptide chains and Cu catalyzed azide alkyne cycloaddition reaction to graft these chains onto the silica surface is reported. This methodology enables the synthesis of well-defined polypeptide chains that are attached onto the silica surface at high surface densities. The PLGA-silica conjugate particles are well dispersed in water, and have been thoroughly characterized using multinuclear ((13)C, (29)Si) solid state NMR, thermogravimetric analysis, Fourier transform infrared, dynamic light scattering, and transmission electron microscopy. The pH-dependent reversible aggregation of the PLGA-silica particles, driven by the change in PLGA structure, has also been studied. Preliminary results on the use of aqueous dispersions of silica-PLGA for the preparation of three-dimensional macroporous structures with oriented pores by ice templating methodology are also demonstrated. These macroporous materials, comprising a biocompatible polymer shell covalently attached to rigid inorganic cores, adopts an interesting lamellar structure with fishbone-type architecture.
多肽涂层的硅纳米粒子是一类很有趣的有机-无机杂化材料，因为多肽接枝的有序二级结构赋予了这些纳米粒子功能性。本研究采用 N-羧酸酐（NCA）聚合来合成多肽链，并通过铜催化的叠氮-炔基环加成反应将这些链接枝到硅纳米粒子表面，从而制备了聚 L-谷氨酸（PLGA）硅纳米粒子杂化物。这种方法可以合成具有明确结构的多肽链，并以高表面密度接枝到硅纳米粒子表面。PLGA-硅纳米粒子杂化物在水中具有良好的分散性，并通过多核（(13)C、(29)Si）固态 NMR、热重分析、傅里叶变换红外、动态光散射和透射电子显微镜进行了全面的表征。研究了 PLGA-硅纳米粒子在 pH 依赖性条件下的可逆聚集行为，这是由 PLGA 结构变化引起的。还展示了使用水相分散的硅-聚 L-谷氨酸制备具有定向孔的三维大孔结构的初步结果，该方法采用冰模板法。这些大孔材料由共价连接到刚性无机核上的生物相容性聚合物壳组成，具有有趣的层状结构和鱼骨型架构。
