Microencapsulation of mesenchymal stromal cells in covalent alginate hydrogels for cell therapy

Ambrosino, M.; Nativel, F.; Boyer, C.; Lagneau, N.; Loll, F.; Halgand, B.; Djouad, F.; Renard, D.; Tessier, A.; Guicheux, J.; Delplace, V.; Le Visage, C.

doi:10.1101/2023.11.27.568852

bioRxiv · 10.1101/2023.11.27.568852

Microencapsulation of mesenchymal stromal cells in covalent alginate hydrogels for cell therapy

Ambrosino, M.·Nativel, F.·Boyer, C.·Lagneau, N.·Loll, F.·Halgand, B.·Djouad, F.·Renard, D.·Tessier, A.·Guicheux, J.·Delplace, V.·Le Visage, C.

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Abstract

Osteoarthritis (OA) is the most common inflammatory joint disease and currently lacks an effective curative treatment. Intra-articular injection of mesenchymal stromal cells (MSCs) has gained attention as a relevant therapeutic approach for OA treatment due to the MSCs ability to secrete anti-inflammatory and immunomodulatory factors. Given their limited viability post- intraarticular injection and the potential leakage of cells out of the injection site, encapsulating MSCs in hydrogels is considered a promising strategy to protect them and provide a suitable 3D microenvironment to support their biological activities. Calcium-cross-linked alginate hydrogels are commonly used for MSC encapsulation, but their long-term in vivo stability remains uncertain. On the other hand, alginate cross-linking by the strain-promoted azide- alkyne cycloaddition (SPAAC) reaction would create a network unaffected by an ionic environment. Hence, this study aimed to develop an alginate-based hydrogel cross-linked via stable and cytocompatible covalent bonds for cell encapsulation. We established for the first time the formation of covalent alginate hydrogels between two SPAAC precursors, namely alginate-BCN and alginate-N3. These hydrogels exhibited in vitro stability and enabled the diffusion of molecules of interest. We then generated alginate-based SPAAC microgels of 170 m in mean diameter, suitable for intra-articular injection. We next encapsulated human adipose MSCs (hASCs) in these alginate-based SPAAC microgels and confirmed their cytocompatibility, with over 90 % of cells remaining viable after 14 days in culture. Finally, the microencapsulated hASCs maintained their biological properties and were able to secrete anti-inflammatory factors (IDO, PGE2, and HGF) when exposed to pro-inflammatory cytokines (TNF- and IFN-{gamma}). In the end, human-activated lymphocytes were cultured in contact with microencapsulated hASCs, and CD3+ T cell proliferation was quantified by flow cytometry. We demonstrated that the encapsulation process did not impair the hASC immunomodulatory activity. Overall, our findings show the potential of alginate-based SPAAC hydrogels for microencapsulating hASCs for cell therapy.

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Ambrosino, M., Nativel, F., Boyer, C., Lagneau, N., Loll, F., Halgand, B., Djouad, F., Renard, D., Tessier, A., Guicheux, J., Delplace, V., Le Visage, C.. 2023-11-27. Microencapsulation of mesenchymal stromal cells in covalent alginate hydrogels for cell therapy. https://doi.org/10.1101/2023.11.27.568852

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