Studies On The Synthesis And Properties Of Polyhydroxy Hyperbranched Polymer Nanospheres

As a novel kind of functional polymer materials,polymeric microspheres have been widely studied due to their great potential in many application fields,such as medical engineering,biology technology and electronic information.Hyperbranched polymer has advantaged conditions in polymer microsphere field because of its unique three-dimensional structure,a large number of cavity and abundant functional groups.HPG as the representative of hyperbranched polymer has favorable biocompatibility and excellent solubility.A kind of general nanospheres carrier material was prepared by HPG in this paper and studied it basic performance and related application.The detailed content is described as follows.(1)On the basis of numerous functional hydroxyl groups of the HPG,TA molecules were conjugated to the surface of HPG by N,N'-dicyclohexylcarbodiimide(DCC)coupling to prepare different graft yield HPG-TA.FT-IR and NMR analysis indicate that the HPG-TA with different grafting yield was successfully synthesized.Subsequently,the HPG-TA nanospheres was obtained by using nanoprecipitation,dialysis and UV light and the size of HPG-TA nanospheres was controlled by changing TA grafting ratio,HPG-TA concentration and solvent ratio,the result was characterized by DLS,TEM and SEM.Finally,the modification of HPG-TA nanospheres with dodecyl chloride and rhodamine B(RhB)showed that the hydroxyl group on the surface of HPG-TA nanospheres had good activity,it provide a good foundation for the further functionalization of HPG-TA nanospheres.(2)Based on the molecular characteristic of HPG-TA,small dye molecules and drug molecules can be encapsulated in the cavities of HPG-TA molecules respectively,and then HPG-TA nanospheres loaded with dye and drug molecules can be prepared by nano-precipitation,dialysis and UV light.SEM and DLS characterization results showed that the nanospheres size were mostly below 150 nm and had good monodispersity.Furthermore,the stability experiment,degradation experiment,drug release experiment,cytotoxicity evaluation and cell imaging were carried out on the HPG-TA nanospheres loaded with doxorubicin hydrochloride(DOX).The results showed that HPG-TA nanospheres had pH responsiveness,biodegradability,stability and successfully entered cancer cells.(3)Used the HPG-TA as hydrophilic phase transfer carriers and provided a general phase inversion method for oil soluble molecules.The oil-soluble molecules can be coated into HPG-TA nanospheres and transferred to the water phase through the steps of blending,dialysis and UV light with HPG-TA.TEM,DLS,UV and PL were used to characterize the phase inversion experiment,the results show that,after phase inversion,the oil-soluble molecules still retain their own functionality,and HPG-TA nanospheres carrier also had good stability and dispersibility in water.