# Poly(vinyl alcohol)/Gelatin Scaffolds Allow Regeneration of Nasal Tissues
###### Abstract  
Need for regeneration and repair of nasal tissues occurs as a consequence of several pathologies affecting the nose, including, but not limited to infective diseases, traumas and tumor resections. A platform for nasal tissue regeneration was set up using poly(vinyl alcohol)/gelatin sponges with 20%-30% (\(w/w\)) gelatin content to be used as scaffolds, for their intrinsic hydrophilic, cell adhesive and shape recovery properties. We propose mesodermal progenitor cells (MPCs) isolated from the bone marrow as a unique stem cell source for obtaining different connective tissues of the nose, including vascular tissue. Finally, epithelial cell immune response to these scaffolds was assessed in vitro in an environment containing inflammatory molecules. The results showed that mesenchymal stromal cells (MSCs) deriving from MPCs could be used to differentiate into cartilage and fibrous tissue; whereas, in combination with endothelial cells still deriving from MPCs, into pre-vascularized bone. Finally, the scaffold did not significantly alter the epithelial cell response to inflammatory insults derived from interaction with bacterial molecules. bioarthritis; mesenchymal stem cells; mesodermal progenitor cells; 3D model; tissue engineering; cartilage; vascularized bone; fibrocartilage; rhinoplasty +
Footnote †: journal: Medical Imaging  
The nasal septum acts as a support for the other nose structures to confer rigidity, thus preventing its permanent deformation. Through the lateral cartilages, the nose interfaces with the nasal bones, such as the vomer, the perpendicular plate of ethmoid bone, and incisive bone, which determine nose anchoring to the facial structures [4,6]. Proceeding from the surface to the depth of the nose, a series of layers are present, made up of different tissues devoted to stability and protection against mechanical shocks along with ensuring the correct organ function: the adipose panniculus, the fibromuscular layer rich in vessels, muscles and ligaments, the deep adipose layer and the muco-perichondrium [7, 8, 9]. Furthermore, two fibrocartilaginous sacs have recently been identified, one right and one left, linked to the development of nasal cartilages and containing, in their walls, the olfactory mucosa [3]. Given its filtering function and its position, the nose is exposed to a series of injuries of traumatic, chemical, inflammatory and tumorigenic origin [4]. The most common injuries are septal deformations, which cause obstructions of the airways. In addition, nose is subject to tumors, rare but extremely variegated in nature, whose resection causes profound alterations in the cartilaginous structures. Surgery is necessary to repair the damaged anatomical tissues, which, depending on the injury, may require subsequent revisions [10,11]. The surgical procedures currently employed are rhinoplasty and septoplasty, which often exploit cartilaginous grafts to repair damaged structures [2]. The gold standard is autologous cartilage obtained from the septum itself, the auric or the ribs. The first site is easily accessible, but the amount that can be recovered is limited; on the contrary, plenty of material can be taken from the ribs, but the removal procedure causes donor site morbidity [12, 13, 14]. As an alternative, it is possible to use allogeneic grafts. Even though their actual immunogenicity is not known, the limited cellular phase present in cartilage suggests a limited risk [15,16]. Finally, it is possible to apply synthetic materials, which can be molded into the desired shapes, they are cheap and implantable in a single procedure; however, they can lead to sustained inflammation up to device extrusion [17,18]. Thus, an effective and simple reconstructive procedure with minimal side effects has yet to be developed. A novel approach to nasal reconstruction is shown by tissue engineering (TE).