Deep Eutectic Solvents: Emerging Green Solvents for Biomedical Innovations

Deep eutectic solvents (DESs) have emerged as a transformative class of green solvents with immense potential in biomedical sciences due to their tunable physicochemical properties, low toxicity, environmental compatibility, and cost-effective synthesis. Formed by mixing hydrogen bond donors and acceptors, DESs exhibit unique solvating abilities that allow them to dissolve a broad range of bioactive compounds, macromolecules, and biomaterials. In biomedical innovation, DESs have demonstrated promising applications in drug delivery, extraction of phytopharmaceuticals, therapeutic formulations, cryopreservation, enzyme stabilization, and regenerative medicine. Their structural adaptability enables improved solubility and bioavailability of poorly water-soluble drugs, fostering next-generation formulation design. Natural deep eutectic solvents (NADES), derived from biological metabolites, further enhance the biocompatibility and sustainability profile by mimicking intracellular environments and facilitating safe interactions with living tissues. Recent advances highlight the role of DESs in enhancing transdermal and oral drug delivery, modulating membrane permeability, and enabling green synthesis of nanoparticles for therapeutic and diagnostic uses. Additionally, DESs offer novel opportunities in tissue engineering as non-toxic media for cell preservation, scaffold fabrication, and biomolecule stabilization. Despite their promising attributes, challenges remain regarding long-term toxicity, biodegradability, regulatory acceptance, and standardization of physicochemical characterization. Addressing these gaps through systematic studies and interdisciplinary collaboration will accelerate the adoption of DESs in clinical and pharmaceutical settings. This chapter provides an in-depth exploration of DES fundamentals, biomedical applications, safety considerations, and future perspectives, highlighting their pivotal role in supporting green, sustainable, and innovative healthcare technologies.