Tissue implantation test in rabbits with gelatine sponges

The purpose of this implantation study was to evaluate possible toxic effects and quality and quantity of resorption of two different resorbable gelatine sponges when implanted into the paravertebral muscle of the rabbit for a period of 7, 14 or 21 days and to evaluate bioequivalence of two types of test material. Test materials (Gelaspon) and a commercially available reference material were compared in three groups with 6 rabbits each. Tissue reaction to the implants and sponge degradation were scored on a graded scale and the sponges were compared for evaluation. No treatment-related mortality or body weight changes were observed. Clinical signs, indicative of local effects, were mainly seen for reference material. Tissue reaction after 7 days was comparable, after 14 and 21 days a significant increase in granulomatous reaction was seen for reference material. Sponge degradation was complete for test materials after 14 and 21 days without inflammatory tissue reaction, but small sponge rests of reference material were still present, accompanied by an increased inflammatory response. Results show test materials to fulfil the clinical requirements for implant material concerning fast resorption without inflammatory reactions and its superiority to reference material. Bioequivalence of used types of test material could be confirmed.