Controlled release of canine MSC-derived extracellular vesicles by cationized gelatin hydrogels

Karin Yoshizaki; Hidetaka Nishida; Yasuhiko Tabata; Jun-Ichiro Jo; Ikuhiko Nakase; Hideo Akiyoshi

doi:10.1016/j.reth.2022.11.009

Controlled release of canine MSC-derived extracellular vesicles by cationized gelatin hydrogels

Regen Ther. 2022 Dec 10:22:1-6. doi: 10.1016/j.reth.2022.11.009. eCollection 2023 Mar.

Authors

Karin Yoshizaki¹, Hidetaka Nishida¹, Yasuhiko Tabata², Jun-Ichiro Jo^{2

3}, Ikuhiko Nakase⁴, Hideo Akiyoshi¹

Affiliations

¹ Department of Veterinary Surgery, Graduate School of Life and Veterinary Science, Osaka Metropolitan University, Izumisano, Osaka, Japan.
² Laboratory of Biomaterials, Department of Regeneration Science and Engineering Institute for Life and Medical Sciences, Kyoto University, Kyoto, Kyoto, Japan.
³ Department of Biomaterials, Osaka Dental University, Hirakata, Osaka, Japan.
⁴ Graduate School of Science, Osaka Metropolitan University, Sakai, Osaka, Japan.

Abstract

Introduction: Canine mesenchymal stem cell (MSC)-derived extracellular vesicles (EVs) have emerged as a promising form of regenerative therapy. Therapeutic application of EVs remains difficult due to the short half-life of EVs in vivo and their rapid clearance from the body. We have developed cationized gelatin hydrogels that prolong the retention of EVs to overcome this problem.

Methods: Canine MSCs were isolated from bone marrow. MSC-derived EVs were isolated from the culture supernatant by ultracentrifugation. Gelatin was mixed with ethylene diamine anhydrate to cationized. Distinct cross-linked cationized gelatin hydrogels were created by thermal dehydration. Hydrogels were implanted into the back subcutis of mice in order to evaluate the degradation profiles. Hydrogels with collagenase were incubated at 37 °C in vitro to quantize the release of EVs from hydrogels. Lipopolysaccharide (LPS)-stimulated BV-2 cells were used to evaluate the immunomodulatory effect of EVs after release from the hydrogels.

Results: The cationized gelatin hydrogels suppressed EV release in PBS. More than 60% of immobilized EVs are not released from the hydrogels. The cationized hydrogels released EVs in a sustainable manner and prolonged the retention time of EVs depending on the intensity of cross-linking after degradation by collagenase. The expression of IL-1β in LPS-stimulated BV-2 cells was lower in EVs released from the hydrogels than in controls.

Conclusions: Our results indicate that the controlled release of EVs can be achieved by cationized gelatin hydrogels. The released EVs experimentally confirmed to be effective in reducing proinflammatory response. The cationized gelatin hydrogels appear to be useful biomaterials for releasing canine MSC-derived EVs for regenerative therapy.

Keywords: Canine; Controlled release; Extracellular vesicle; Gelatin; Hydrogel; Mesenchymal stem cell.