![Sample our Physical Sciences journals, sign in here to start your FREE access for 14 days]({"type":"image" , "src" : "/sda/110819/TOC-Subject-Sample-2021-Physical-Sciences.jpg"})
Abstract
Nanocarriers based on amphiphilic block copolymers, with tailored temperature and pH responsiveness, were prepared. The hydrophilic blocks consist of temperature-sensitive [N-isopropylacrylamide (NIPAAm)] or NIPAAm plus pH-sensitive units [5-methacryloyloxy pentatonic acid (5MPA) or 4-methacryloyloxy benzoic acid (4MBA)], while the hydrophobic block is composed of n-hexyl acrylate (HA) or styrene (ST). Particle sizes were within the suitable range for the desired application (30–182 nm). Drug loading was achieved via an organic solvent-free method and a THF-buffer method leading to drug loadings of indomethacin, tetracycline and doxorubicin of up to 11, 11 and 60 wt%, respectively. In vitro release kinetics were performed under simulated physiological conditions (pH 7.4 and 37 °C; pH 6.0 and 40 °C) and show differences depending on the copolymer composition. The average kinetic data were well fitted to the mathematical model of Peppas. NIPAAm-containing copolymers were slight or non-cytotoxic for rat primary hepatocytes at concentrations less than 200 µg mL−1. Some of the polymeric aggregates prepared may find application as pharmaceutical carriers.
Acknowledgements
This investigation was supported by the Consejo Nacional de Ciencia y Tecnología (CONACYT) of Mexico under grants CB-2012/178709 and INFR-2016/26955; furthermore by the Universidad Autónoma de Sinaloa under grant PROFAPI2014/156. Technical support by Y. Cristerna-Madrigal (UAS), M. Díaz-Duarte and I.A. Rivero (IT-Tijuana) is gratefully acknowledged.
Disclosure statement
No potential conflict of interest was reported by the authors.