Isocyanate-terminated urethane prepolymer as bioadhesive material: Evaluation of bioadhesion and biocompatibility, in vitro and in vivo assays

Attempts have been made to evaluate the degree of bioadhesion and biocompat ibility of a synthesized urethane prepolymer with specially tailored micros tructure. Wetting behaviour and extent of interfacial adhesion of the prepa red prepolymer towards biological substrates were examined by in vitro meth ods. The former was carried out by measuring the contact angle between drop s of the prepolymer liquid and a biological surface, while the latter was d etermined from the force between the prepolymer and tissue model or mucus. The obtained results exhibited good tissue wettability and bioadhesion by t he prepolymer. Preliminary evaluation of biocompatibility for the uncatalyt ically cured prepolymer films was performed by cytotoxicity and histotoxici ty experiments. Results showed a significant growth for the adhered L929 fi broblast cells within a period of 5 days incubation. Also, no severe inflam matory tissue response towards the samples implanted in rabbit for 16 weeks was seen. These observations can support the potentiality of the designed urethane prepolymer to be applied as hemostatic agent.