IN-SITU ASSESSMENT OF CELL VIABILITY WITHIN BIODEGRADABLE POLYLACTIC ACID POLYMER MATRICES

Efforts to expand treatment options for articular: cartilage repair ha ve increasingly focussed on the implantation of cell polymer construct s. Primary cells cultured from perichondrium, a chondrogenic tissue, w ere found to survive in vitro within a biodegradable porous polylactic acid matrix. The novel application of an in situ fluorescent double-s tain protocol to cell polymer constructs was supported by increased H- 3-thymidine uptake and the ability of cell seeded polylactic acid to f orm first passage explant cultures. This in situ viability staining te chnique allowed for rapid determination of cell viability and, in conj unction with confocal microscopy, assessment of cellular distribution within a biodegradable scaffold. Advantages of using this method over histological and electron microscopic analysis include in situ observa tion, absence of distortion in scaffold architecture due to polymer di ssolution and disruption during processing, and obtaining a viability assessment within 30 min. Potential applications of this protocol as a screening tool for laboratory engineered tissues and in the evaluatio n of cellular injury in natural tissues are discussed.