Mechanical and Cellular Response to Biomineralization of Ovalbumin Scaffolds for Bone Tissue Engineering

Studies regarding the feasibility of ovalbumin (OVA) as a bone scaffold material have found its cost, availability, interaction with cells, and ability to degrade in the body into safe byproducts to be ideal for such an application. However, weak mechanical properties cause hesitation in the use of OVA as a scaffolding material in much stronger native tissue. To enhance the mechanical strength of the OVA scaffolds without compromising in vitro cellular performance, Ca-P crystals were grown on unmodified OVA and phosphonated OVA (p-OVA) samples via biomineralization processes using 5x-concentrated simulated body fluid (5x SBF).

Electron microscopy (ESEM/EDS) data confirm the formation of Ca-P crystals on the surface of OVA and p-OVA scaffolds. Mechanically, rheology data measured a minimum of a three-fold increase in each mineralized scaffold's complex shear modulus over unmineralized counterparts. Degradation in a PBS+collagenase XI environment showed that mineralization extended total time to degradation. It was also shown that the formation of the Ca-P crystals had no negative effects on in vitro cell studies. To measure cellular response, a live/dead assay was conducted to confirm cell viability after 24 hours.

In conclusion, improvements were made to mechanical strength without compromising in vitro cell-scaffold response. While it remains unknown whether the increase in strength is adequate for use as a bone scaffold, future work should focus on gathering necessary information to study OVA scaffolds in animal models for eventual consideration as a bone graft substitute material.