SPECIAL CONSIDERATIONS IN EMBEDDING A LACTIDE ABSORBABLE POLYMER

Absorbable biomaterial implants are advantageous in that they require no retrieval surgery and they absorb as the affected tissue heals. The nature of the in vivo or in vitro absorption process may be determine d by processing, embedding, and sectioning an explanted specimen and s urrounding tissue or by directly embedding and sectioning an in vitro specimen. It is important to utilize an embedding medium that will not chemically interact with the polymer, in order to accurately determin e the tissue/material absorption interaction. Poly-1-lactide absorbabl e polymeric films were embedded in 5 different resins to observe the c hemical interaction between the resin and the absorbable material and to examine the relative ease of sectioning: methylmethacrylate, hydrox yethyl methacrylate, paraffin, epoxy, and polyester based resins. Para ffin, epoxy, and polyester resins best preserved the surface of the fi lms. The study further suggests that paraffin may be too soft for moni toring materials used in long term absorption studies and that polyest er is suitable only if polymerization is initiated before the material is embedded. Hydroxyethyl methacrylate was the most susceptible to en vironmental conditions. In all cases, the direction of sectioning had a substantial impact on the section quality.