Animal-derived extracellular vesicles and vesicle-like nanoparticles: linking natural bioactivity to precision therapeutics

Animal-derived extracellular vesicles (AEVs) and animal-derived vesicle-like nanoparticles (AVLNs) are emerging natural nanocarriers with diverse bioactive cargoes, potential biocompatibility, and capacity for cross-species molecular communication. This narrative review distinguishes naturally released AEVs from AVLNs obtained through tissue processing without sufficient evidence of natural extracellular release. It covers particles from glandular secretions, tissues, and cultured cells, focusing on isolation, characterization, molecular composition, biodistribution, biological functions, therapeutic mechanisms, and translational potential. Source-dependent proteins, lipids, and nucleic acids can modulate disease-relevant signaling and recipient-cell responses, contributing to immunomodulatory, anti-inflammatory, antitumor, regenerative, antioxidant, antibacterial, and antiviral activities. However, evidence derives predominantly from in vitro studies and preclinical animal models, with substantial heterogeneity in preparation, characterization, dose reporting, and outcome assessment; most reported therapeutic effects have not been clinically established. Cargo signatures may inform vesicle identity, biological activity, and therapeutic response, but their diagnostic and predictive value remains exploratory and requires clinical validation. Major translational challenges include inconsistent terminology, limited methodological standardization, cargo heterogeneity, uncertain biodistribution, and biosafety concerns, particularly immunogenicity and long-term safety. Addressing these limitations and validating relationships among vesicle sources, functional cargoes, molecular targets, and disease indications will be essential to translate intrinsic bioactivity into reproducible platforms for precision therapeutics.