In vitro Biological Evaluation of Small Intestinal Submucosa - Chitosan / Hyaluronic Acid Tridimensional Scaffolds as Deep Wound Healing Dressings

In the U.S. more than 6 million patients suffer from chronic wounds (e.g., diabetic, pressure or vascular ulcers), which represent a major public health issue and an important healthcare expenditure. Chronic deep wounds lose the ability to repair without the external signals responsible for enhancing extracellular matrix (ECM) restoration and promoting sustained healing. We have previously prepared Small Intestinal Submucosa-Chitosan (SIS-Ch) and Small Intestinal SubmucosaHyaluronic Acid (SIS-HA) 3D scaffolds, in the form of porous sponges and hydrogels. Physicochemical and mechanical properties in vitro confirmed their potential as wound dressings. Here we conducted in vitro biological tests of SIS-Ch (n=3) and SIS-HA (n=3) scaffolds that included MTT assays to determined cytotoxicity and hemolysis assay to assess the tendency to damage red blood cells. Cell viability of SIS-Ch and SIS-HA sponges exceeded 80%. Nevertheless, SIS-HA hydrogels exhibited the greatest cell viability values of all formulations most likely due to the HA natural function in extracellular matrix that promotes cell migration and proliferation. The presence of Ch and HA in the scaffolds correlated with higher cell metabolic rates when compared with formulations based on SIS only (p<0.05). Hemolytic indexes below 5% were found for all formulations except for SIS_Ch Low and SIS_HA High for porous sponges, confirming thereby their limited tendency to promote hemolysis. Our in vitro biological findings suggest that both SIS-Ch and SISHA scaffolds have the characteristics to be evaluated in preclinical in vivo testing.