Background: Exosomes are nanosized extracellular vesicles that participate in intercellular communication by transferring proteins, lipids, and nucleic acids. They are known to regulate a variety of biological and physiological processes. Colostrum, the first secretion of the mammary gland after parturition, is rich in bioactive molecules that support immune defense and tissue growth. Despite this, the structural and functional characteristics of exosomes derived from goat colostrum remain largely unexplored. Objective: The aim of this study was to isolate exosomes from goat colostrum, characterize their physical and biochemical features, and evaluate their effects on
fibroblast cell viability. Methods: Fresh colostrum was collected from healthy goats within a few hours after kidding. Samples were sequentially centrifuged (۶,۰۰۰–۲۰,۰۰۰ g) and filtered through ۰.۴۵ µm and ۰.۲۲ µm PVDF membranes, followed by ultracentrifugation at ۱۰۰,۰۰۰ g. The pellets were resuspended in phosphate-buffered saline (PBS), stored at −۷۰°C, and analyzed for protein concentration using the Bradford assay (۹.۵۷ mg/mL). Exosomes were characterized by dynamic light scattering (DLS), zeta potential measurement (−۱۶.۵ mV), field-emission and transmission electron microscopy (FE-SEM and TEM), SDS-PAGE, and FTIR spectroscopy. Their biological effects were assessed through MTT assays on human and mouse
fibroblast cells. Results: Electron microscopy confirmed that the isolated vesicles were spherical to oval, ranging from ۵۰ to ۹۵ nm, with a mean hydrodynamic diameter of ۱۴۲.۸ nm by DLS. FTIR spectra showed peaks corresponding to phospholipids and amide bonds typical of exosomal membranes. Cell viability assays revealed no cytotoxicity; instead,
fibroblast survival increased to around ۱۱۲% after ۷۲ hours at ۱ mg/mL. Conclusion: This study successfully isolated goat colostrum–derived exosomes and demonstrated their ability to enhance
fibroblast proliferation without toxicity. These findings suggest their potential application as safe, natural, and biocompatible agents for tissue repair and regenerative medicine.