Preparation of Foam Dressings Based on Gelatin, Hyaluronic Acid, and Carboxymethyl Chitosan Containing Fibroblast Growth Factor-7 for Dermal Regeneration.

Wound recovery close to the function of the native skin is the goal of wound healing. In this study, we prepared foam dressings (FDs; 2-GHC-FD-1-9, 5-GHC-FD-1-9, and 10-GHC-FD-1-9) composed of various concentrations of gelatin, hyaluronic acid, and carboxymethyl chitosan, which are chemically interconnected through amide bond formation, for evaluating wound healing. Tensile and cell proliferation tests showed that 2-GHC-FD-1-9 are suitable for wound dressing. For further evaluation, three types of FDs, 2-GHC-FD-1, 2-GHC-FD-4, and 2-GHC-FD-8 were chosen. The results of animal intradermal reactivity, water vapor transmission rate, and absorption rate of the three FDs indicated that 2-GHC-FD-8 is the most appropriate scaffold for wound healing. For wound healing acceleration, various concentrations of fibroblast growth factor-7 (FGF-7) was soaked in 2-GHC-FD-8 (2-GHC-FD-8/F1-6) and evaluated by using scanning electron microscopy, cell proliferation, release behavior, and in vivo animal tests. The FDs showed interconnected porous structures, increased cell proliferation until 8.0 × 10-11 M, controlled release with initial burst within 1 h, and sustained release for 48 h. The results of the animal test showed an appropriate concentration of FGF-7 for wound healing. In addition, 2-GHC-FD-8 is a suitable scaffold for wound healing. Therefore, we suggest that 2-GHC-FD-8/F3 is a useful wound dressing for accelerating wound healing.

Comparative Study on the Effect of the Different Harvesting Sources of Demineralized Bone Particles on the Bone Regeneration of a Composite Gellan Gum Scaffold for Bone Tissue Engineering Applications.

Bone is the rigid tissue that constitutes the skeleton. The material for bone regeneration has to provide the mechanical stability by maintaining the mechanical loads both in the rest conditions and during the body movements. Bone is dynamic tissue constantly reshaped by the action of cells (osteoblasts and osteoclasts). This activity is normally enough to heal bone injuries; however, in several conditions, when bone is subjected to fatal damages, self-renewal is difficult, if not even impossible, and a medical treatment is required. The transplantation of a biomaterial is one of the common surgical procedures to overcome critical injuries. In this study, we exploited the effect of the use of different sources of demineralized bone powder (DBP) in combination with gellan gum (GG) to form a GG-DBP hydrogel scaffold with the purpose of regenerating the bone tissue. DBP was extracted from the femurs of two typologies of Gallus gallus domesticus (the Yeonsan Ogye, a traditional and rare black chicken from Korea, and the Cornish cross, the most common breeds for industrial meat production) and the Pekin duck. The composite scaffold has been tested both in vitro and in vivo. In vitro studies using rat bone marrow-derived mesenchymal stem cells (rBMSCs) confirmed the cellular suitability of bone-specific gene expression for seeded GG-DBP scaffolds, differentiation capacity, and marked upregulation. The scaffold containing a DBP derived from the Yeonsan Ogye (YO) bone showed higher levels of cell proliferation and osteogenic differentiation in comparison with the scaffold with the DBP obtained from the other studied sources. These results have been related with the higher amount of melanin, studied by fluorescence, of the YO DBP compared to Cornish cross and Pekin duck. Overall, this study clearly shows the use of YO DBP as a promising material in bone tissue regeneration.