Deep eutectic solvents in biomedical applications: A mini review

Deep eutectic solvents (DESs) have gained much attention due to their potential to replace conventional solvents in various biomedical applications while being more environmental friendly and easily tuneable in terms of their physicochemical properties. The mini-review aims to cover recent developments in the application of DESs in biomedical fields, with emphasis on their potential to solve some of the problems that have plagued the pharmaceutical and biomedical industries for decades. Natural deep eutectic solvents (NADES), which are usually composed of food-grade or generally recognized as safe (GRAS) compounds such as choline chloride and various sugars and organic acids, have low cytotoxicity in in vitro and in vivo models and are therefore considered safe for use in biomedical applications. In addition, DESs have been found to have profound effects on the controlled release of drugs and the stabilization of therapeutic nanoparticles in various pharmaceutical formulations. Therapeutic deep eutectic solvents (THEDES), in which the active pharmaceutical ingredient forms part of the solvent matrix, have also been found to have great potential in the formulation of novel drug delivery systems that integrate solubilization and therapeutic activity in one compound. Despite these developments and advancements in the application of DESs in various pharmaceutical and biomedical applications, some issues remain to be resolved regarding their standardization and scale-up of production. In this mini-review, the general audience will have access to the conceptual framework of the application of DESs and the recent knowledge on their safety and stability in various biomedical applications. • DESs and NADES offer biocompatible, low-toxicity options for biomedical use. • DESs enhance solubility, stability, and bioavailability of challenging drugs. • THEDES enable drug-integrated solvents for improved and controlled delivery. • DESs support drug delivery, biosensing, tissue engineering, and nanomedicine. • Many DESs show antimicrobial and antioxidant activity for healing applications.