Chitosan, chondroitin sulfate, and hyaluronic acid based in-situ forming scaffold for efficient cell grafting.

Current cell grafting techniques are majorly dependent on seeding cells on a pre-formed scaffold. However, cells grow in a 2-dimensional (2D) space in such constructs, not mimicking the tissue's 3-dimensional (3D) architecture. The present study evaluated a unique poly-electrolyte complexation (PEC) based strategy for the 3D engraftment of cells in a porous polymeric scaffold. The scaffold was synthesized using a positively charged polysaccharide chitosan (CH) and negatively charged glycosaminoglycans chondroitin sulfate (CS) and hyaluronic acid (HA). Two different scaffolds were synthesized, one using CH and CS [CH-CS] and another using CH and CS + HA [CH-(CS-HA)]. The physicochemical characterization of both the PECs confirmed electrostatic interactions, leading to a porous and viscoelastic PEC formation. Fibroblast cells were grafted and seeded in both scaffolds to evaluate the effect of different scaffold compositions and the difference between seeded and grafted cells. Imaging studies confirmed that grafting of the fibroblast cells supports cellular proliferation. The qPCR studies demonstrated increased expression of functional markers TGF-ß, α-SMA, collagen-I, and fibronectin in the CH-(CS-HA) grafted cells. In summary, it was demonstrated that an in-situ forming PEC of CH, CS, and HA had good physicochemical properties for cell grafting and supported grafted cells with improved function.

Dual antibacterial and anti-inflammatory efficacy of a chitosan-chondroitin sulfate-based in-situ forming wound dressing.

None of the currently available wound dressings exhibit combined antibacterial and anti-inflammatory activity. Using polyelectrolyte complexation (PEC) between a cationic polysaccharide chitosan (CH) and an anionic glycosaminoglycan chondroitin sulfate (CS), we have developed a unique in-situ forming scaffold (CH-CS PEC), which develops at the wound site itself to influence the function of the wound bed cells. The current study demonstrated that CH-CS PEC could induce bacterial cell death through membrane pore formation and increased ROS production. Moreover, possibly due to its unique material properties including medium-soft viscoelasticity, porosity, and surface composition, CH-CS PEC could modulate macrophage function, increasing their phagocytic ability with low TNF-α and high IL-10 production. Faster wound closure and decreased CFU count was observed in an in-vivo infected wound model, with reduced NF-κB and increased VE-cadherin expression, indicating reduced inflammation and enhanced angiogenesis. In summary, this study exhibited that CH-CS PEC has substantial antibacterial and immunomodulatory properties.