Fabrication and Evaluation of Physical and Biological Properties of Hydroxyethyl Cellulose/Hyaluronic Acid-Based Scaffolds Used for Second-Degree (Partial-Thickness) Burns Wounds Healing

The purpose of this study was to prepare and compare a hydroxyethyl cellulose/hyaluronic acid (HEC/HA)-based scaffold with and without gelatin for the treatment of second-degree partial-thickness burns. The scaffolds were prepared by freeze-drying method from the aqueous solutions of the mentioned polymers. Microstructural examination by scanning electron microscopy (SEM) indicated the average pore size of 120 and 98 µm for the gelatin-free and gelatin-containing scaffolds, respectively. According to the dynamic rheology measurements (DMA), all the solutions were flowable in which, the loss modulus was higher than the storage one. Moreover, the solutions revealed shear-thinning behaviour at low frequencies, which changed to shear thickening at frequencies higher than 100 s-1. Both loss and storage modulus increased by adding gelatin to the polymer solutions. The scaffolds water uptake was up to 3,000%. The addition of gelatin to the HA/HEC solution increased the polymer network collapse up to 2 hours and led to reducing the scaffolds degradation rate. Cytotoxicity assay in the presence of the scaffolds showed that more than 80 % of the fibroblast cells were viable (compared to the control group), meanwhile, the presence of  gelatin had a positive effect on the metabolic activity of the cells and increased the rate of cell proliferation.  Scratch test results showed the ability of scaffolds to increase the cell migration rate compared to the control sample. The hydroxyethyl cellulose/hyaluronic acid/gelatin scaffold due to the presence of gelatin and improved the cell migration, which indicating the rapid re-epithelialization, reduced wound contraction to   73 % within 24 hours.