Toxicology and safety research of poly(N-isopropylacrylamide)-based thermosensitive nanogels

Poly(N-isopropylacrylamide) (PNIPAM) is currently the most studied thermosensitive hydrogel. Due to its low critical transition temperature, which is close to human body temperature, it is widely used in the biomedical field. The temperature-sensitive embolic agent based on PNIPAM nanogel utilizes the sol-gel transition characteristics of PNIPAM at different temperatures to solve the contradiction between the fluidity and embolic performance of traditional embolic agents. However, research on the toxicology and safety of PNIPAM-based biomedical materials has not been widely explored. In this study, for the first time, an embolic agent composed of PNIPAM thermosensitive nanogels was taken as the object of research, to explore systematically the potential toxicology risks. We achieved specific detection of PNIPAM nanogels by fluorescent labeling. On this basis, pharmacokinetic, safety, and effectiveness studies were carried out in different animal and in vitro models, and organs in which free nanogels might accumulate when a large number of nanogels enter the blood circulation were analyzed. The results show that PNIPAM-based nanogels have good biocompatibility. This study aims to provide a relevant toxicology research program for PNIPAM-based nanogels and other medical products that may contain nanomaterials, and promote the clinical application of this biomedical material, which has great potential.