Evaluation of the cell viability and in vivo biocompatibility of three potential regenerative biomaterials derived from eggshells in Wistar rats

The development of novel bone substitutes for the management of periodontal osseous defects requires assured biological function upon implantation. Chicken egg shells have been introduced for some time in reconstructive surgeries due to their mineral composition. Egg shells are among the most abundant byproducts of food processing waste and appear to have unique biological and chemical properties that support cell differentiation. Additives such as fish collagen and glycerine may enhance their efficacy by improving their regenerative properties, which mimic those of human bone, and increasing their handling characteristics. Biocompatibility and cell viability are two critical factors affecting the ability of any regenerative material to integrate into the body. The aim of the present study was to determine the cell viability and biocompatibility of three egg shell‑derived biomaterials, namely, egg shell‑derived hydroxyapatite (EHPA), EHPA modified with fish collagen EHPA/Coll, and EHPA/Coll with glycerine. Chicken egg shells were used to synthesise hydroxyapatite via chemical precipitation. The synthesised hydroxyapatite was modified with fish collagen and then with glycerol. All three materials were tested for their viability in mouse fibroblasts and for their in vivo biocompatibility in Wistar rats. The results revealed that eggshell‑derived hydroxyapatite was highly biocompatible and did not exert any cytotoxic effects. Its modification using fish collagen and glycerine also resulted in derivatives that were biocompatible and noncytotoxic. On the whole, the present study demonstrates that all three materials tested, which were eggshell derivatives, were highly biocompatible and promoted cell growth.