Novelty in the development of biodegradable polymer coatings for biomedical devices: paclitaxel grafting on PDMMLA derivatives

Biocompatible and biodegradable polymers are widely used in the medical field. In some cases, the biopolymer is accompanied by an active drug, which is delivered locally in a controlled manner in order to improve the healing conditions. Poly([R,S]-3,3-dimethylmalic acid) (PDMMLA) is a synthetic amphiphilic biodegradable polymer, which unlike PLA, can be chemically modified to adapt hydrophilic/hydrophobic balance, degradation kinetics, and physicochemical and biological properties. It may contain a lateral alkyl group or a functional group for coupling bioactive molecules to release during its degradation. In this work, we realized the chemical grafting of paclitaxel (PTX), a microtubule stabilizing anti-cancer agent on PDMMLA derivatives bio-polyesters following a Steglich esterification protocol. 1D and 2D NMR analyses validated the reaction with 10% (using 0.1 equivalent) of PTX on the copolymer PDMMLAH(40)-co-Hex(60) (PDMMLA 40/60) and a maximal PTX grafting rate of 55% on the homopolymer PDMMLAH (PDMMLA 100/0). In vitro adhesion and cytotoxicity assays were carried out on HUVEC cells with PDMMLA 40/60, PDMMLA-PTX 30/10/60 and PLA.