Influnce of Calcium and Alginate Concentration on Human Chondrocyte Survival

ABSTRACT

The calcium alginate matrix, which has been used as a delivery vehicle for autogenous transplantation of the human chondrocytes, should provide a suitable environment for chondrocyte survival and for generation of new cartilage-like tissue. To optimize calcium alginate condition for human chondrocytes, the viscosity and concentration of sodium alginate and the CaCl2 concentration were varied during manufacture of the alginate discs. Human rib cartilage was dissected, enzymatically dissociated, and the chondrocytes were collected by centrifugation. Chondrocyte viability measured after fourteen days of culture by quantification of the DNA content per alginate discs. Sodium alginate concentrations were tested at four different levels varying from 0.5% to 3 percent using both low and moderate viscosity alginates. The DNA content was highest at 0.5% percent and lowest at 3 percent with both alginates. Varying the CaCl2 concentrations for polymerization from 50 to 200 mM produced no difference in DNA content. These data demonstrate that sodium alginate concentration rather than CaCl2 concentration is a critical factor for successful encapsulation of human cartilage cells in a calcium alginate matrix.