Study On Drug Delivery Systems Based On Dopamine Self-polymerization

Dopamine(DA), as a kind of important neurotransmitters in the human body, plays an important role in various physiological activities. The presence of primary amine and catechol groups in DA permits a large pool of functional molecules to be grafted to the surfaces of the materials. DA can self-polymerize to form melanin-like Polydopamine(PDA) in a mild basic environment(pH 8.5). The general methods are used to prepare PDA ?lms and particles which provide a platform for post-modi?cation. What’s more, the low cytotoxicity of PDA makes it have potential applications in biomedical fields.1、Study on synthesis and drug delivery of PDA submicrospheresPDA submicrospheres were synthesized by facilely oxidative self-polymerization of DA. The as-prepared PDA submicrospheres were monodisperse, with an average diameter of approximately 220 nm. The PDA submicrospheres exhibit ultralow cytotoxicity and excellent biocompatibility, which lays a solid foundation for its application in biomedical fields. Subsequently, The anticancer drug paclitaxel(PTX) were successfully introduced to the surface of PDA submicrospheres by adsorption properties. The drug loading and release amount demonstrated that the PDA submicrospheres have the potential for serving as hydrophobic drug carriers for anticancer treatments.2、Synthesis of PDA nanospheres and its applications on cancer treatmentBy adjusting the pH value and molar ratio of ethanol and water, A versatile ethanol-mediated oxidative polymerization of DA was demonstrated to prepare the monodisperse PDA nanosphere with an average diameter of approximately 40 nm. Subsequently, PTX was bound covalently to the surface of PDA nanospheres through a succession of chemical modi?cations. The drug loading and release amount of PTX-PDA conjugation was measured in vitro. The PTX-PDA nanospheres can be readily internalized by cancer cells and have a similar cytotoxicity with clinic PTX injection Taxol®. However, PDA nanospheres alone did not induce the damage effects on cells. In short, the prepared PTX-PDA drug delivery systems can be delivered into MCF-7 and CT-26 cells and preserves the anticancer activities on the induction of mitotic blockage, apoptosis and anti-tumorigenesis.3、Preparation of CdSe/ZnS@PDA composite nanomaterials and its applications on cancer therapy.The CdSe/ZnS@PDA composite nanomaterials were synthesized by concise ligand exchange method. The anticancer drug DOX was selected as model drug to study drug delivery. We observed that the CdSe/ZnS@PDA composite nanomaterials are water-soluble and stable with high colloidal properties in water. The photology properties of CdSe/ZnS@PDA are similar before and after modification. The cytotoxicity experiments showed that the CdSe/ZnS@PDA have lower cytotoxicity and better biocompatibility. The CdSe/ZnS@PDA composite nanomaterials with 5-6 nm in diameter were relatively easy to enter the cell and to be removed through kidneys, so it is more suitable for biomedical applications for anticancer treatments.