Development of heparinized agarose microspheres for the recovery of exosomes curing acute myocardial infarction.

Exosomes carry biological molecules that are secreted by cells. They play a crucial role in intercellular communication and regulate physiological and pathological processes. This study develops heparinized agarose microspheres (HepCAMs) for affinity purification of EVs from a culture medium to address problems with low purity and scaling up. HepCAMs are used for exosome affinity purification using human lung adenocarcinoma alveolar epithelial cells (A549) and Human Umbilical Mesenchymal Stem Cells (HUMSCs) in a culture medium. The presence of purified exosomes is confirmed by measuring the particle size, concentration, morphology and surface markers. This method to isolate HepCAMs achieves twice the purity of exosomes at 8.9 × 107 particles/μg of protein than the SEC method. The bioactivity of HUMSCs exosomes that are purified using the HepCAMs is verified by measuring the internalization and wound healing of Human Umbilical Vein Endothelial Cells (HUVECs). For a myocardial infarction (MI) mouse model, HUMSCs exosome restores cardiac performance and blood flow recovery in myocardial infarction mice. These results show that the proposed method to isolate HepCAMs produces high-purity exosomes and the process is easily scaled up. The bioactivity of exosomes is confirmed and they are shown to improve heart function after ischemic injury in a MI mouse model.