Membrane nanofibrose a base di policaprolattone/gelatina ottenute tramite l'elettrospinning per ricreare in vitro la membrana basale della barriera alveolo-capillare = Polycaprolactone/gelatin-based nanofibrous membranes obtained by electrospinning to recreate in vitro the basement membrane of the alveolus-capillary barrier

The alveolar-capillary barrier is the place where gas exchanges take place in the lungs and consists of a layer of alveolar epithelium and capillary endothelium, separated by an interstitial space and a basement membrane. The basement membrane provides elastic support to the barrier during respiratory movements, through the combined action of collagen fibres, proteoglycans and other extracellular matrix proteins (ECM). Tissue Engineering (TE) is a multidisciplinary field that include the knowledge of different disciplines with the aim to repair, regenerate or replace damaged organs or tissues by the development of biological substitutes (scaffold). The scaffold, a three-dimensional porous template, acts as a temporary extracellular matrix allowing cell adhesion, proliferation and growth. In recent years, the interest in using biodegradable and bioresorbable composite biomaterials has grown, thanks to mechanical properties of synthetic polymers and biological properties of natural polymers. The aim of this work is to manufacture polycaprolactone/gelatin nanofibrous matrices (scaffolds) to recreate in vitro the basement membrane of the alveolar-capillary barrier. Three polymeric solutions of blend (PCL /GEL), gelatin (GEL) and polycaprolactone (PCL) were processed using the electrospinning technique. Electrospun membranes were morphologically characterized by SEM (electron scanning microscope), highlighting the random structure of the nanofibers. The membranes obtained from the polymeric solution of blend show more uniform and defect-free fibres. In addition, quasi-static and dynamic (cyclic) tensile tests were conducted, finding good mechanical properties for both PCL-based and blend fibres (good deformability and flexibility) and poor mechanical properties for GEL samples. The wettability of the surfaces of the membranes was assessed through an analysis of the contact angle, obtaining values about of 25 ° for blend, 45 ° for GEL and 138 ° for PCL. The stability of the membranes was assessed under static and dynamic conditions (inside a commercial bioreactor to simulate the physiological conditions of the alveolus-capillary barrier), showing a good resistance of the blend and PCL membranes.