Preparation of Nature Mimicked Composite Materials for Tissue Regeneration

Abstract

Skeletal defect is the second largest reason that leads to disability in worldwide. The bone is the most common transplanted tissue after blood. Bone regeneration strategy remains a significant challenge in the treatment. The filling of the lesion is an important factor to evaluate regenerative ability of implant along with its bioactivity. Most of regenerative commercial approaches are not very practical to use. Their application in trauma site caused varied degrees of damage to normal tissues. Pre-formed scaffolds cannot fill irregular defects as good as in situ forming implant. In-situ formed implants received great attention as they provided ease of use along with excellent healing capacity. A thermosensitive in situ forming hydrogels are synthesized by crosslinking of Chitosan (CS), Zein (ZN) and Hydroxyapatite (HA). CS, ZN and HA are biocompatible, economical, and biodegradable materials, used in range of biomedical applications. HA is gold standard biomineral used for excellent regeneration of bone tissue. ZN is a good source of amino acids that can help in regeneration of collagen matrix of hard and soft tissues. CS is the second most abundant natural biopolymer having excellent ability to from thermosensitive hydrogels. The major challenge of in situ forming implants is relatively low mechanical strength. To improve the mechanical strength and biological performance ZN is used. HA is synthesized via economical co-precipitation method. CS/HA/ZN thermosensitive hydrogel of different composition CS.HA.ZN (0), CS.HA.ZN (25), CS.HA.ZN (50) CS.HA.ZN (75) CS.HA.ZN (100) are prepared. Changing the pH of CS solution gradually acidic to neutral converted it to gel phase. Appropriate reagents that gradually change the pH are used. Here very less explored calcium glycerophosphate (Ca.GP) is used. Ca.GP help is contains Calcium and phosphate groups that are also component of hard tissue so presence of this also facilitate regeneration. Thermo sensitive in situ forming hydrogels are prepared by optimizing by changing the amount of neutralizing agent’s and Ca.GP and sodium bicarbonate (NaHCO3). CS, ZN and HA solution in the presence of neutralizing agents at 10 -12 °C existed in solutions form and constituted to hydrogels setting at 37 °C in 6-7 minutes.