Standards for In-Vitro and In-Vivo Comparison and Qualification of Bioabsorbable Polymers

The bioabsorbable polymers poly(DL-lactic acid), poly-(isobutyl 2-cyanoacrylate), and poly(methyl 2-cyanoacrylate) have been evaluated comparatively in organ and cell cultures in vitro and in rat muscle tissues in vivo. Effects of the polymers on cell ultra-structure in organ cultures, on cell surface characteristics, and cell population doubling times in cell cultures have been correlated with hemorrhage, fibrosis, and necrosis. This correlation has been used to establish three cytotoxicity points (highly, moderately, and minimally toxic) for characterization or prediction of the in vivo behavior of absorbable polymers. As a result of these findings, and because these polymers are readily available, easily characterized, and have long shelf lives, they can be used as reference standards for testing and qualification of bioabsorbable materials.