PLGA‐grafted HA copolymers were synthesized and utilized as target specific micelle carriers for DOX. For grafting hydrophobic PLGA chains onto the backbone of hydrophilic HA, HA was solubilized in an anhydrous DMSO by nano‐complexing with dimethoxy‐PEG. The carboxylic groups of HA were chemically grafted with PLGA, producing HA‐g‐PLGA copolymers. Resultant HA‐g‐PLGA self‐assembled in aqueous solution to form multi‐cored micellar aggregates and DOX was encapsulated during the self‐assembly. DOX‐loaded HA‐g‐PLGA micelle nanoparticles exhibited higher cellular uptake and greater cytotoxicity than free DOX for HCT‐116 cells that over‐expressed HA receptor, suggesting that they were taken up by the cells via HA receptor‐mediated endocytosis.
An electroactive amino/carboxyl‐capped aniline tetramer (AT) is covalently grafted to the surface of hydroxyapatite (HA) nanoparticles to generate novel electroactive HA‐AT nanoparticles. The amount of AT ranges from 16.5 to 34.0 wt% and is characterized by thermogravimetric analysis (TGA). The HA‐AT nanoparticles are characterized by Fourier transform IR (FTIR) spectroscopy, X‐ray photoelectron spectroscopy (XPS), X‐ray diffraction, and scanning electron microscopy (SEM). For the excellent electroactivity of HA‐AT, the mixture of HA‐AT and PLA shows much better adhesion ability and proliferation ability than that of HA and a PLA matrix. At a 15 wt% AT grafting amount, the matrix shows the best biocompatibility.
This paper reports a novel amphoteric aliphatic polycarbonate bearing both amine and carboxyl groups. In the absence of protection‐deprotection chemistry, the multi‐functionalized copolymer is synthesized by one‐step enzymatic copolymerization. The influences of the reaction conditions including monomer feed ratio and polymerization time are explored. The simultaneous incorporation of amine and carboxyl functionalities provides the copolymer with a pH‐tunable self‐aggregation feature, leading to various aggregation states including precipitated agglomerate, well‐dispersed positively or negatively charged nanoparticles in a controlled manner. The copolymer displays minimal cytotoxicity to 293T and HeLa cells.
