Correlation of two bioadhesion assays: the everted sac technique and the CAHN microbalance

This contribution correlates two in vitro methods utilized to determine bio adhesion. One method, the everted intestinal sac technique, is a passive te st for bioadhesion involving several polymer microspheres and a section of everted intestinal tissue. The other method, the CAHN microbalance, employs a CAHN dynamic contact angle analyzer with modified software to record the tensile forces measured as a single polymer microsphere is pulled from int estinal tissue. This study demonstrates that CAHN and everted sac experimen ts yield similar results when used to quantify the bioadhesive nature of po lymer microsphere systems. A polymer showing high adhesion in one method al so demonstrates high bioadhesion in the other method; polymers that exhibit high fracture strength and tensile work measurements with the CAHN microba lance also yield high binding percentages with the everted sac method. The polymers tested and reported here are poly(caprolactone) and different copo lymer ratios of poly(fumaric-co-sebacic anhydride). The results of this cor relation demonstrate that each method alone is a valuable indicator of bioa dhesion. (C) 1999 Elsevier Science BN. All rights reserved.