Preservation of Small Extracellular Vesicle in Gelatin Methacryloyl Hydrogel Through Reduced Particles Aggregation for Therapeutic Applications

Abstract

Purpose Small extracellular vesicles (sEV) play an irreplaceable role in cell–cell communication. However, sEV in solution aggregate with each other during preservation, leading to impairment of the structures, contents, and functions of sEV. Therefore, there is a need to develop an optimal preservation method that combines high recovery rate, low cost, convenience, and easy-transportation in one. In this study, a new preservation strategy different from the cryopreservation or lyophilization was developed by reducing sEV particles aggregation. Methods The sEV were encapsulated in thermoresponsive gelatin methacryloyl (GelMA) hydrogels at 4°C to reduce particles aggregation during the reversible cross-linking process. The sEV movement was visualized in different mediums and particles’ number, size, structure and protein of 28 days preserved sEV were compared to fresh sEV. Human umbilical vein endothelial cells (HUVEC) and rat adipose-derived stromal stem cells (rASC) were isolated and cultured with fresh and preserved sEV to test the cellular response. A mice subcutaneous model was adopted to detect controlled release and angiogenesis ability of preserved sEV. Results Through particles tracks visualization, GelMA hydrogels significantly decreased the sEV movement. After 28 days preservation in GelMA at 4°C, the particles number, size, structure and protein of sEV were similar to fresh sEV. In vitro, preserved sEV had the same ability to promote cell proliferation, migration and angiogenesis as fresh sEV. In vivo, preserved sEV-GelMA could artificially regulate the absorptivity of GelMA hydrogels and controlled released sEV for therapeutic application, and preserved sEV encapsulated in GelMA significantly promoted angiogenesis in mice. Conclusion Our results demonstrated that sEV encapsulated in GelMA could be a novel strategy for long-term preservation of sEV for therapeutic application.

Autophagosomes Defeat Ferroptosis by Decreasing Generation and Increasing Discharge of Free Fe2+ in Skin Repair Cells to Accelerate Diabetic Wound Healing

“…[ 34 ] GelMA hydrogels have been recognized as attractive tissue‐engineering materials for the release of exosomes and have shown promising applicability in regenerative medicine. [ 35 ] To make the SAPs more applicable to wound healing, we employed a porous GelMA hydrogel to load the SAPs under UV photopolymerization ( Figure 5 a ). GelMA hydrogels (labeled Gel) with different monomer concentrations (5% and 10%) were studied.…”

Functional extracellular vesicles from SHEDs combined with gelatin methacryloyl promote the odontogenic differentiation of DPSCs for pulp regeneration

“…The exploitation of EV in solution may lead to aggregate and explosive release. The hydrogel scaffolds should be properly introduced to provide a hydrophilic 3D polymer network for EV protection and sustained release [ 48 ]. In a previous article on the role of preconditioning of EVs in promoting cell differentiation, the combination of EVs and scaffold was not revealed and it was unclear whether EVs embedded in a hydrogel might have the same effects as free EVs [ 15 ].…”

“…In a previous article on the role of preconditioning of EVs in promoting cell differentiation, the combination of EVs and scaffold was not revealed and it was unclear whether EVs embedded in a hydrogel might have the same effects as free EVs [ 15 ]. It has been proven that EVs encapsulated in GelMA hydrogels are able to maintain their particle number, size, structure, and protein [ 48 ]. For this reason, we chose GelMA as the scaffold for EV encapsulation in the present study.…”

Extracellular Vesicles in Hepatocellular Carcinoma: Progress and Challenges in the Translation from the Laboratory to Clinic

“…However, lyophilization requires the use of freeze-drying agents, which can be harmful to cells. GelMA hydrogels is another promising method for preserving EVs at room temperature [ 104 ]. Further research is required in order to assess the safety and efficacy of these methods in clinical settings.…”