Pseudo-branched polyester copolymer: an efficient drug delivery system to treat cancer

Abstract

In this study, a new hyperbranched polyester copolymer was designed using a proprietary monomer and diethylene glycol or triethylene glycol as monomers. The synthesis was carried out using standard melt polymerization technique and catalyzed by p-tolulenesulfonic acid. The progress of the reaction was monitored with respect to time and negative pressure, with samples being subjected to standard characterization protocols. The resulting polymers were purified using the solvent precipitation method and characterized using various chromatographic and spectroscopic methods including GPC, MALDI-TOF, and NMR. We have observed polymers with a molecular weight of 29 643 Da and 33 996 Da, which is ideal to be used as a drug delivery system. Thus, these polymers were chosen for further modification into folate-functionalized polymeric nanoparticles for the targeted treatment of cancer, in this case we have chosen prostate cancer cells as a model. We hypothesized that due to the 3D structure of the A₂B monomer, we expect a pseudo-branched polymer that is globular in shape which will be ideal for drug carrying and delivery. We used a solvent diffusion method for the one-pot formulation of water-dispersable polymeric nanoparticles as well as theraputic drug (doxorubicin) encapsulation. The efficacy of this delivery system was gauged by treating LNCaP cells with the drug-loaded nanoparticles and assessing the results of the treatment. The results were analyzed by cytotoxicity (MTT) assays, drug release studies, and fluorescence microscopy. The experimental results collectively show a nanoparticle that was biocompatible, target-specific, and successfully initiated apoptosis in an in vitro prostate cancer model.