Poly(citric acid)-block-poly(ethylene glycol) Copolymers; New Candidates for Nanomedicine

Linear-dendritic ABA triblock copolymers containing poly(ethylene glycol) (PEG) as B block and hyperbranched poly(citric acid) (PCA) as A blocks were synthesized through polycondensation. The molecular self-assembly of synthesized PCA-PEG-PCA copolymers in water was led to nanoparticles and fibers in different sizes and shapes depend on the time and size of PCA blocks. Ten days after dissolving PCA-PEG-PCA copolymers in water, the size of fibers was reached to several millimeters. Mixing a water solution of fluorescein as a small guest molecule and PCA-PEG-PCA copolymers led to encapsulate fluorescein by products of molecular self-assembly. In order to investigate their potential application in nanomedicine and to understand the limitation and capability of these materials as nanoexcipients in biological systems, the different types of short-term in vitro cytotoxicity experiments on HT1080 cell line (human Fibrosarcoma) and hemocompatibility tests were performed.