Delivery of Immobilized IFN-γ With PCN-333 and Its Effect on Human Mesenchymal Stem Cells

Interferon-gamma (IFN-γ) plays a vital role in modulating the immunosuppressive properties of human mesenchymal stem/stromal cells (hMSCs) used in cell therapies. However, IFN-γ suffers from low bioavailability and degrades in media, creating a challenge when using IFN-γ during the manufacturing of hMSCs. Metal–organic frameworks (MOFs), with their porous interiors, biocompatibility, high loading capacity, and ability to be functionalized for targeting, have become an increasingly suitable platform for protein delivery. In this work, we synthesize the MOF PCN-333(Fe) and show that it can be utilized to immobilize and deliver IFN-γ to the local extracellular environment of hMSCs. In doing so, the cells proliferate and differentiate appropriately with no observed side effects. We demonstrate that PCN-333(Fe) MOFs containing IFN-γ are not cytotoxic to hMSCs, can promote the expression of proteins that play a role in immune response, and are capable of inducing indoleamine 2,3-dioxygenase (IDO) production similar to that of soluble IFN-γ at lower concentrations. Overall, using MOFs to deliver IFN-γ may be leveraged in the future in the manufacturing of therapeutically relevant hMSCs.