▎ 摘　　要

NOVELTY - Immunomagnetic composition comprises a population of magnetic particles, where each magnetic particle is conjugated to at least one pH responsive extracellular vesicle-binding peptide. USE - The immunomagnetic composition is useful for isolating a population of extracellular vesicles from a medium, where the extracellular vesicles comprise exosomes (preferred), ectosomes, microvesicles, microparticles, apoptotic bodies, large oncosomes, exophers, enveloped viruses, and exomeres and the biological fluid comprises cell culture medium, plasma, serum, urine, saliva, tears, perilymph fluid, milk, cerebrospinal fluid, blood, or a plant derived fluid (all claimed). ADVANTAGE - The immunomagnetic composition: utilizes the magnetic particles bound to a pH responsive peptide that are capable of binding to extracellular vesicles and facilitate their isolation using a magnetic field and can be recycled for multiple uses; utilizes the polydopamine that allows easy surface modification and bioconjugation of the peptides and prevent their degradation and increase their half-life; possesses excellent biocompatibility and resistance to biofouling; releases intact, specific exosomes populations without introducing exogenous capture probes; enables the integration of surface engineering and drug loading for producing therapeutic functional exosomes; enables the development of transferrable, standardized production protocols via precise control of electromagnetic field and buffer pH; offers simple, rapid, and streamlined workflow which is compatible manufacturing bioreactor for scale up; and enables the preparation of homogeneous therapeutic exosomes at scale for clinical translation and improving lung delivery specificity. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for: (1) isolating (M1) a population of extracellular vesicles from a medium, comprising contacting the medium with the immunomagnetic composition and optionally an aqueous solution to form a mixture, adjusting the pH of the mixture to 3-5 to bind the population of magnetic particles to the population of extracellular vesicles, and collecting the population of extracellular vesicles bound to the magnetic particles by applying a magnetic field; (2) a population of extracellular vesicles isolated by the method (M1); (3) a composition comprising the population of extracellular vesicles and an excipient; and (4) a kit comprising the immunomagnetic composition, and an aqueous solution for dispersing the immunomagnetic composition.