Nanocrystalline Cellulose as a Versatile Engineering Material for Extrusion-Based Bioprinting

Recent advances in 3D bioprinted polysaccharide hydrogels for biomedical applications: A comprehensive review

Polysaccharide hydrogels, which can mimic the natural extracellular matrix and possess appealing physicochemical and biological characteristics, have emerged as significant bioinks for 3D bioprinting. They are highly promising for applications in tissue engineering and regenerative medicine because of their ability to enhance cell adhesion, proliferation, and differentiation in a manner akin to the natural cellular environment. This review comprehensively examines the fabrication methods, characteristics, and applications of polysaccharide hydrogel-driven 3D bioprinting, underscoring its potential in tissue engineering, drug delivery, and regenerative medicine. To contribute pertinent knowledge for future research in this field, this review critically examines key aspects, including the chemistry of carbohydrates, manufacturing techniques, formulation of bioinks, and characterization of polysaccharide-based hydrogels. Furthermore, this review explores the primary advancements and applications of 3D-printed polysaccharide hydrogels, encompassing drug delivery systems with controlled release kinetics and targeted therapy, along with tissue-engineered constructs for bone, cartilage, skin, and vascular regeneration. The use of these 3D bioprinted hydrogels in innovative research fields, including disease modeling and drug screening, is also addressed. Despite notable progress, challenges, including modulating the chemistry and properties of polysaccharides, enhancing bioink printability and mechanical properties, and achieving long-term in vivo stability, have been highlighted.

Biomaterial engineering for cell transplantation

The current paradigm of medicine is mostly designed to block or prevent pathological events. Once the disease-led tissue damage occurs, the limited endogenous regeneration may lead to depletion or loss of function for cells in the tissues. Cell therapy is rapidly evolving and influencing the field of medicine, where in some instances attempts to address cell loss in the body. Due to their biological function, engineerability, and their responsiveness to stimuli, cells are ideal candidates for therapeutic applications in many cases. Such promise is yet to be fully obtained as delivery of cells that functionally integrate with the desired tissues upon transplantation is still a topic of scientific research and development. Main known impediments for cell therapy include mechanical insults, cell viability, host's immune response, and lack of required nutrients for the transplanted cells. These challenges could be divided into three different steps: 1) Prior to, 2) during the and 3) after the transplantation procedure. In this review, we attempt to briefly summarize published approaches employing biomaterials to mitigate the above technical challenges. Biomaterials are offering an engineerable platform that could be tuned for different classes of cell transplantation to potentially enhance and lengthen the pharmacodynamics of cell therapies.