A Review of Chondroitin Sulfate's Preparation, Properties, Functions, and Applications

Sulfated polysaccharide as biomimetic biopolymers for tissue engineering scaffolds fabrication: Challenges and opportunities

Sulfated polysaccharides play important roles in tissue engineering applications because of their high growth factor preservation ability and their native-like biological features. There are different sulfated polysaccharides based on different repeating units in the carbohydrate backbone, the position of the sulfate group, and the sulfation degree of the polysaccharide. These led to various sulfated polymers with different negative charge densities and resultant structure-property relationships. Since numerous reports are presented related to sulfated polysaccharide applications in tissue engineering, it is crucial to review the role of effective physicochemical and biological parameters in their usage; as well as their structure-property relationships. Within this review, we focused on the effect of naturally occurring and synthetic sulfated polysaccharides in tissue engineering applications reported in the last years, highlighting the challenges of the scaffold fabrication process, the position, and the degree of sulfate on biomedical activity. Additionally, we discussed their use in numerous in vitro and in vivo model systems.

Influence of natural polysaccharides on the morphology and properties of hybrid vaterite microcrystals

Co-precipitation of biopolymers into calcium carbonate crystals changes their physicochemical and biological properties. This work studies hybrid microcrystals of vaterite obtained in the presence of natural polysaccharides, as carriers for the delivery of proteins and enzymes. Hybrid microcrystals with dextran sulfate, chondroitin sulfate, heparin, fucoidan, and pectin were obtained and compared. The impact of polysaccharides on the morphology (particle diameter, surface area, nanocrystallite and pore size), polysaccharide content and surface charge of hybrid microcrystals was studied. Only microcrystals with fucoidan and heparin exhibited antioxidant activity against •ОН radical. The surface charge and pore size of the hybrid microcrystals affected the sorption of albumin, catalase, chymotrypsin, mucin. A decrease in the catalytic constant and Michaelis constant was observed for catalase sorbed on the hybrid crystals. The biocompatibility of microcrystals depended on the nature of the included polysaccharide: crystals with sulfated polysaccharides increased blood plasma coagulation but not platelet aggregation, and crystals with dextran sulfate had the greatest cytotoxicity against HT-29 cells but not erythrocytes. Hybrid microcrystals with all polysaccharides except chondroitin sulfate reduced erythrocyte lysis in vitro compared with vaterite crystals. The obtained results enable to create novel carriers based on hybrid vaterite crystals with polysaccharides, beneficial for the delivery of protein drugs.

Sulfated Chitosan Nanofibrous Scaffolds Seeded With Adipose Stem Cells Promote Ischemic Wound Healing in a Proangiogenic Strategy

Ischemic wounds are chronic wounds with poor blood supply that delays wound reconstruction. To accelerate wound healing and promote angiogenesis, adipose-derived stem cells (ADSCs) are ideal seed cells for stem cell-based therapies. Nevertheless, providing a favorable environment for cell proliferation and metabolism poses a substantial challenge. A highly sulfated heparin-like polysaccharide 2-N, 6-O-sulfated chitosan (26SCS)-doped poly(lactic-co-glycolic acid) scaffold (S-PLGA) can be used due to their biocompatibility, mechanical properties, and coagent 26SCS high affinity for growth factors. In this study, a nano-scaffold system, constructed from ADSCs seeded on electrospun fibers of modified PLGA, was designed to promote ischemic wound healing. The S-PLGA nanofiber membrane loaded with adipose stem cells ADSCs@S-PLGA was prepared by a co-culture in vitro, and the adhesion and compatibility of cells on the nano-scaffolds were explored. Scanning electron microscopy was used to observe the growth state and morphological changes of ADSCs after co-culture with PLGA electrospun fibers. The proliferation and apoptosis after co-culture were detected using a Cell Counting Kit-8 kit and flow cytometry, respectively. An ischemic wound model was then established, and we further studied the ability of ADSCs@S-PLGA to promote wound healing and angiogenesis. We successfully established ischemic wounds on the backs of rats and demonstrated that electrospun fibers combined with the biological effects of adipose stem cells effectively promoted wound healing and the growth of microvessels around the ischemic wounds. Phased research results can provide a theoretical and experimental basis for a new method for promoting clinical ischemic wound healing.