INTERACTION BETWEEN FIBRONECTIN-BEARING SURFACES AND BACILLUS-CALMETTE-GUERIN (BCG) OR GELATIN MICROPARTICLES

Gelatin, prepared commercially by degradation of animal collagen, was studied to see whether it had an affinity for fibronectin, which has a known affinity for collagen, and whether gelatin-based drugs could be used to target fibronectin-excreting tumours. Bacillus Calmette-Gueri n (BCG) vaccine, an attenuated strain of Mycobacterium bovis, is curre ntly the most effective treatment for superficial transitional cell ca rcinoma of the bladder. The living cells of the BCG vaccine associate with the fibronectin-bearing surfaces of the tumour. Using a multi-wel l culture plate technique, gelatin microparticles were shown to be ads orbed onto murine S180 sarcoma cells and this reaction was substantial ly inhibited by the addition of human plasma fibronectin. The aviditie s of various BCG substrains and gelatin microparticles for glass-bound fibronectin were measured and the association constants determined. T he gelatin microparticles associated with the fibronectin with equal a vidity as the BCG cells. The results suggest that this model system ma y allow the investigation of gelatin-based drug delivery devices capab le of targeting fibronectin-bearing surfaces associated with some tumo urs.