Polymeric scaffold for wound healing monitoring based on biocompatible textile organic electrochemical transistor

Recently, wearable devices have grown in importance, especially in healthcare, for their ability to collect crucial data, with noninvasive detection, to monitor patient's physiological conditions. An emerging application is the monitoring of dangerous wounds, to detect the ulcer status. For chronic or infected wounds, the literature reports a pH interval between 6.5 and 9, with a high dependence on the healthy development of the wound. Our objective is to realize an innovative scaffold capable of monitoring ulcers healing, starting from high biocompatible materials to ensure a correct interaction with the physiology of the wound. The scaffold has been constituted by a synthetic biocompatible material, poly(ether)urethane-polydimethylsiloxane (PU-PDMS), was manufactured by spray, phase-inversion technique. This scaffolds has been successfully used in combination with fibrin as delivery system for VEGF, bFGF and platelet lysate in preclinical wound healing experiments. A micro-fibrillar tubular scaffold was obtained using a 1% polymer solution and H2O as non solvent (I layer) and 2% and H2O (II layer) and was lyophilized. The morphological analysis of PU-PDMS scaffold surfaces was performed by stereo-microscope after Sudan Black B staining, to ensure a correct shape surface interaction. The scaffold realized in such a way has been functionalized with a biocompatible conductive polymer (PEDOT:PSS), used as detector in Organic Electrochemical Transistor architecture. This polymer presents a high sensitivity to positive ions in liquid environment and allows to determine ions concentration in easy and stable way. The fiber textile electrochemical device has been realized by a dipping process and connected with specific electric contact to create a channel and a gate electrode to control the modulation changes of the sensor. The device functionality was proved on human serum at different pH (between 4 and 10). The morphological analysis showed a dense, non porous surface obtained with the 2% solution, while a porous surface was obtained with the 1% solution where the PEDOT:PSS was positioned. This feature was maintained after lyophilization and re-hydratation. The characteristic of the device was tested showing the sensitivity to saline concentration and the effective functionality of the device. The device shows a sensitivity to pH change. The functionalized scaffold could be used as a wearable detector for wound healing monitoring in patients affected by chronic lesions.