Natural and synthetic polymeric hydrogel: A bioink for 3D bioprinting of tissue models

Abstract

Bioprinting is an emerging field that is revolutionizing medicine, it offers great cells, proteins, improving genes, drugs, and bioactive particle controls, tissue generation and formation. These advances are expected in tissue engineering of functional tissues. Tissue modelling could be used to solve the problems associated with clinical practice such as organ transplantation and immune rejections. Hydrogels are frequently employed as delivery vehicles for tissue engineering techniques such as biocompatibility, adaption of physical, mechanical, and chemical qualities to natural niches, and hence that can provide a better environment for cell growth. These properties of the hydrogels can be tuned according to their application. The cell-interactive qualities can be improved through surface functionalization, mechanical property tuning, degradation rate control, the addition of bioactive molecules, the use of cell-responsive polymers, surface topography, integration with other materials, cell encapsulation, and other techniques. Tissue engineering applications can greatly benefit from the high hydration and ability of hydrogels to imitate the extracellular matrix (ECM) of living things. They have potential to promote cell adhesion, proliferation, and differentiation. This review enlightens the recent advancement in the field of 3D bioprinting and also discusses the basic principles and techniques used in the preparation of hydrogels, along with their types. Choosing the right hydrogel or preparation material is an important step in 3D bioprinting for tissue engineering applications to get the desired output. Therefore, knowledge of the characteristics, advantages and drawbacks of polymeric hydrogels is needed. The natural and synthetic polymers were used for the preparation of 3D printable hydrogel for application in tissue modelling and regeneration (bone, cartilage, heart, nerve tissue). Material from natural sources such as collagen, gelatin, fibrin, and silk were used to prepare hydrogel, which is a kind of protein-based bioink. However, polysaccharide-based bioinks were prepared from alginate, hyaluronic acid, chitosan, agarose, carrageenan and cellulose. All these polymers, along with synthetic polymers like poloxamers, PLGA, polyethylene glycol, polylactic acid etc., are also discussed in detail.