Production of osteogenic and angiogenic factors by microencapsulated adipose stem cells varies with culture conditions.

Growth factors produced by stem cells aid in the bone repair process. We investigated the ability of encapsulated rat adipose-derived stem cells (rASCs) treated with osteogenic media (OM) to produce growth factors, and determined the optimal combination of OM components that will lead to the production of both osteogenic and angiogenic factors. Our results demonstrate that microencapsulated stem cells were able to produce vascular endothelial growth factor (VEGF), fibroblast growth factor-2, and bone morphogenetic protein-2 (BMP2) necessary for bone regeneration.

Microencapsulation of Stem Cells for Therapy.

An increasing demand to regenerate tissues from patient-derived sources has led to the development of cell-based therapies using autologous stem cells, thereby decreasing immune rejection of scaffolds coupled with allogeneic stem cells or allografts. Adult stem cells are multipotent and are readily available in tissues such as fat and bone marrow. They possess the ability to repair and regenerate tissue through the production of therapeutic factors, particularly vasculogenic proteins.

Development of a cell delivery system using alginate microbeads for tissue regeneration.

Alginate microbeads incorporating adipose-derived stem cells (ASCs) have potential for delivering viable cells capable of facilitating tissue regeneration. These microbeads are formed in calcium crosslinking solutions containing organic osmolytes to ensure physiological osmolality, but the comparative effects of these osmolytes on the microencapsulated cells are not known. In addition, delivery parameters needed to use microencapsulated cells for tissue regeneration remain unknown.

Controlled release of rat adipose-derived stem cells from alginate microbeads.

Cell-based therapies have potential for tissue regeneration but poor delivery methods lead to low viability or dispersal of cells from target sites, limiting clinical utility. Here, we developed a degradable and injectable hydrogel to deliver stem cells for bone regeneration. Alginate microbeads <200 μm are injectable, persist at implantation sites and contain viable cells, but do not readily degrade in-vivo.