Cell encapsulating biomaterial regulates mesenchymal stromal/stem cell differentiation and macrophage immunophenotype

Area of Science:

• Biomaterials Science
• Stem Cell Biology
• Immunology

Background:

• Mesenchymal stromal/stem cells (MSCs) are promising for regenerative medicine, but their delivery and survival can be limited.
• Encapsulating MSCs in biomatrices may enhance delivery and residence time compared to intravenous administration.
• The interaction between MSCs, macrophages (Møs), and biomaterials is complex and not fully understood, particularly regarding MSC differentiation and Mø immunophenotype within the matrix.

Purpose of the Study:

• To investigate the three-way interaction between MSCs, Møs, and collagen-based biomaterials.
• To examine how biomatrix encapsulation affects MSC multipotency and Mø immunophenotype.
• To understand the impact of biomaterial properties on MSC differentiation and immunomodulatory functions.

Main Methods:

• Encapsulation of MSCs within collagen-based biomaterials.
• Co-culture of MSCs with Møs within biomatrices.
• Assessment of Mø immunophenotype, including tumor necrosis factor-α secretion.
• Evaluation of MSC differentiation into osteoblasts, chondrocytes, and adipocytes.

Main Results:

• Tumor necrosis factor-α secretion by Møs was acutely inhibited at 4 days.
• MSCs co-cultured with Møs showed reduced chondrocyte differentiation but enhanced osteoblast differentiation.
• Adipocyte differentiation of MSCs was significantly enhanced within a gelatin/polyethylene glycol-based matrix.

Conclusions:

• Biomatrix encapsulation influences the immunomodulatory capacity of MSCs and their interactions with Møs.
• The specific biomaterial composition impacts MSC differentiation pathways, affecting osteogenesis, chondrogenesis, and adipogenesis.
• Understanding these cell-biomaterial-immune cell interactions is crucial for developing effective MSC-based therapies utilizing biomaterials.