Abstract

SMART EXOSOMES IN ACTION: STIMULI-RESPONSIVE STRATEGIES FOR CONTROLLED DRUG DELIVERY

Anuja P. Patil*, Bishal Singh, Omkar Mane

Abstract

Exosomes are considered to be very promising nanocarriers in innovative approaches to drug delivery owing to their biocompatibility, low immunogenicity, and inherent capacity to facilitate intercellular communication. In recent years, increasing attention has been given to the development of construction of stimuli-responsive exosome-based drug delivery systems, whereby therapeutic delivery can be targeted and controlled in response to a particular physiological or external stimulus. This review provides a comprehensive overview of exosomes biology, their formation, structure and main aspects that affect their formation and functional characteristics. Special focus is given to the incorporation of stimuli-responsive approaches into exosome-based systems. The internal stimuli, including pH changes, enzyme overexpression and redox imbalances that exist in the pathological conditions are investigated in their ability to trigger site-specific drug release. Moreover, external stimuli like light irradiation provide possibilities of remote and spatiotemporal regulation of the therapeutic delivery. This review also discusses dual and multi-responsive systems, which can enhance targeting efficiency and eliminate constraints of single-trigger methods. In addition, the review discusses the various biomedical uses of exosomes such as targeted cancer therapy, gene delivery, neurological applications, regenerative medicine, and diagnostic biomarker development. Although these developments are promising, a number of issues still persist, especially the ability to produce in large quantities, standardization, efficiency in loading cargo and the long-term safety testing. In general, stimuli-responsive exosome-based systems are a fast-growing and highly adaptable platform that can play a major role in precision medicine. Their translation may be accelerated by continued advancements in engineering strategies and manufacturing technologies.

Keywords: Exosomes, Extracellular vesicles, Drug delivery, Nanocarriers.