Transglutaminase crosslinked sodium caseinate/starch/tri calcium phosphate based flexible sponge grafts

Abstract

• Green way of crosslinking of natural polymers. • A new method to crosslink water soluble proteins. • Formable, flexible bone scaffolds. In this study, sodium caseinate/starch/ tri-calcium phosphate (TCP) base scaffolds were fabricated and cross-linked with microbial transglutaminase. A Maillard reaction was carried out to stabilize the blend of sodium caseinate (8% w/w) and starch (8% w/w) solutions. The dynamics of enzymatic cross-linking activity were assessed with different TCP concentrations. Freeze-dry method was used to extract water from the gel system to acquire a porous, spongy structure. Apart from many other enzymes, microbial transglutaminase has the capability to be active even below freezing temperatures. Keeping at −50 °C for 12 h, enzymes were still active to complete the post-crosslinking process. 0.5% TCP case resulted in 690 kPa ultimate tensile strength at dried state. Cell activity and characterization tests were elucidated and observed that those scaffolds can have very promising applications in bone tissue engineering.