Hydroxyapatite-Based Colloidal Gels Facilitate the Proliferation and Migration of Chondrocytes and the Adhesion of Umbilical Cord Mesenchymal Stem Cells

Collective movement of cells that have been delivered on biomaterials for transplantation purposes would be a desirable attribute that would promote wound healing, cell proliferation, and eventual growth and regeneration of damaged organs. We hypothesized that colloidal gels made from hydroxyapatite (HA) and poly(D,L-lactic-co-glycolic acid) (PLGA) particles will be conducive to the growth and migration of porcine chondrocytes, will allow the adhesion of human umbilical cord mesenchymal stem cells, and will have negligible effects on the cell cycle of these cells. Then, we performed experiments designed to assess the viability and migratory properties of porcine chondrocytes studded on nanosized HA/PLGA particles. Our experiments show that porcine chondrocytes migrated in and around a hydroxyapatite-based biomaterial that could be described as a colloidal gel. Cells in the colloidal gel demonstrated unidirectional movement. Cells were seen to be extending lamellae and were followed by other cells.