3D bioprinted alginate-gelatin based scaffolds for soft tissue engineering.

Increase in the number of patients suffering from Osteoarthritis is prevalent nowadays and hence, there is need for tissue regeneration. Fabricating a 3D structure giving a better control mimicking the actual tissue properties, especially for osteo-chondral applications is a challenge due to several constraints (like suitable biomaterial for cell encapsulation, mimicking mechanical properties). Here, we mimic the natural process of tissue formation by encapsulating cells in an optimized 3D construct which improves mechanical properties by matrix secretion. We investigated different concentrations of Alginate-Gelatin ink and further characterized the optimized concentration. Behaviour of different infill percentage on the bioactivity and morphology of the scaffold was also investigated. For observing the behaviour of cells on different infill percentages within the scaffolds of same concentration, we used osteoblasts (MG63) cells. The optimized material concentration with the adequate infill showed printability, adequate viscosity, and increased swelling. Both, 20 and 25% infill within the Alginate-Gelatin scaffolds (2.5% w/v Alginate and 5% w/v Gelatin) resulted in higher viability and proliferation of osteoblast cells. Additionally, to control the shape retention ability of the scaffolds dual crosslinking was applied. Thus, the developed Alginate-Gelatin based 3D scaffold maintains the required balance between biomechanics and soft tissue regeneration.