Tuning the rheological properties of chitosan/alginate hydrogels for tissue engineering application

Biomaterials that mimic biological tissues are in great demand in tissue engineering. Hydrogels are rising as a conducive candidate in tissue engineering on account of their water-holding capacity, mechanical strength, and elasticity. Nevertheless, the development of hydrogels that mimic biological tissues with the desired stability and mechanical strength, remains a notable barrier. In this investigation, chitosan/alginate hydrogels were prepared by tuning the chitosan concentration from 0.5 to 2.5%w/v with a fixed 1%w/v alginate concentration using 0.1% glutaraldehyde as a gelling agent. The hydrogel system forms through covalent bonding between chitosan and alginate, mediated by aldehyde groups of the glutaraldehyde. The mechanical strength of the hydrogel was elucidated by probing its viscoelastic behavior through rheological analysis. The rheological investigations revealed that the prepared chitosan/alginate hydrogels are profoundly stable with shear-thinning characteristics. The increase in chitosan concentration enhanced the stability and viscoelastic attributes of the hydrogels. The yield stress values ranging from 0.93 kPa to 14.24 kPa indicate the possibility of using these hydrogels in bioadhesives and soft and bone tissue engineering. The complex modulus of the prepared chitosan/alginate hydrogels resembles the shear modulus of liver tissues, osteogenic cells, and articular cartilage, and hence, these hydrogels pose as suitable candidates in liver, bone, and cartilage tissue engineering. The chitosan/alginate hydrogels possess outstanding self-healing ability, along with biocompatibility, stability, and mechanical strength, rendering them highly advantageous for applications in biomedical tissue engineering and bioadhesives.