孢粉素的物理化学性质和生物医学应用研究进展*

孢粉素是类聚乙烯醇链通过酯键和缩醛高度交联的天然生物高分子,构成花粉和孢子的外壁,能够抵抗物理、化学、生物腐蚀,堪称自然界最坚固的有机物,被誉为植物界的金刚石。孢粉素微囊(SEC)自然界来源丰富、生物相容性好、无免疫原性,表面含有丰富的羧基、羟基和酚基,能够功能化或者与其他纳米材料构建复合材料;其表面丰富的纳米孔道增加了材料的比表面积,有利于捕获癌细胞或目标生物分子。SEC独特的性质使其在药物载体、口服疫苗载体、影像诊断、生物传感、细胞生长支架、微反应器、微型机器人等方面得到广泛的应用。阐述了孢粉素的结构、物理化学性质、制备方法和功能化方面的研究进展, 探讨了孢粉素的应用前景、存在的问题以及未来的发展方向。

Advances of the Physiochemical Properties of Sporopollenin and Its Biomedical Applications

Sporopollenin (SP) is a highly cross-linked natural biopolymer composed of polyvinyl alcohol-like unit crosslinked through ester and acetal linkage. SP forms the outer wall of pollen and spore and can resist physical, chemical and biological corrosion. It is the most robust organic compound in nature and is known as the diamond of plant kingdom. Sporopollenin exine capsules (SEC) are abundant in nature. They have good biocompatibility and no immunity. The rich carboxyl, hydroxyl and phenolic groups make SEC easy to be functionalized or complexed with nanomaterials. The plentiful nanochannels on SEC increases their specific surface area, supporting capture of cancer cell and biomolecules. The unique properties of SEC lead to their wide applications in drug delivery carriers, oral vaccine carriers, medical imaging, biosensing, cell growth scaffold, microreactor, micro robot, etc. In this review, the physicochemical properties, preparation methods and functionalization of SP as well as the research progress of SEC are discussed. The application prospect, existing problems and future development direction of SEC are summarized.