Injectable Polymeric Systems Based on Polysaccharides for Therapy

Microbial polysaccharides are inexpensive natural polymers synthesized by various microorganisms such as bacteria, fungi, and microalgae. They have been generally used in the food industry as emulsifier, gelling agents, and thickeners. Nowadays, their favourable biological properties, similarity to native ECM, and wide range of molecular weights, and functional groups have sparked the interest of researchers for their use as injectable scaffolds used in drug delivery, tissue engineering and regenerative medicine. Notable applications of microbial polysaccharides are vaccine preparations and intra-articular injections of hydrogels in osteoarthritis therapy. These systems provide minimally invasive routes of implantation in vivo to locally deliver drugs, cells, and other therapeutics in a controlled manner. They may also provide a stable environment to support cell differentiation and migration to enhance tissue regeneration. The various uses of microbial polysaccharides and their derivatives as injectable scaffolds used in therapy are reviewed herein.