The golden rule in tissue engineering is the creation of a synthetic device that simulates the native tissue, thus leading to the proper restoration of its anatomical and functional integrity, avoiding the limitations related to approaches based on autografts and allografts. The emergence of synthetic biocompatible materials has led to the production of innovative scaffolds that, if combined with cells and/or bioactive molecules, can improve tissue regeneration. In the last decade, silk fibroin (SF) has gained attention as a promising biomaterial in regenerative medicine due to its enhanced bio/cytocompatibility, chemical stability, and mechanical properties. Moreover, the possibility to produce advanced medical tools such as films, fibers, hydrogels, 3D porous scaffolds, non-woven scaffolds, particles or composite materials from a raw aqueous solution emphasizes the versatility of SF. Such devices are capable of meeting the most diverse tissue needs; hence, they represent an innovative clinical solution for the treatment of bone/cartilage, the cardiovascular system, neural, skin, and pancreatic tissue regeneration, as well as for many other biomedical applications. The present narrative review encompasses topics such as (i) the most interesting features of SF-based biomaterials, bare SF’s biological nature and structural features, and comprehending the related chemo-physical properties and techniques used to produce the desired formulations of SF; (ii) the different applications of SF-based biomaterials and their related composite structures, discussing their biocompatibility and effectiveness in the medical field. Particularly, applications in regenerative medicine are also analyzed herein to highlight the different therapeutic strategies applied to various body sectors.

We investigate and optimize the Aerosol Jet Printing of PEDOT:PSS by studying the role of parameters determining the final quality of the printed features. Printing thin films of organic materials requires a high control in the deposition process to control the morphology/structure of the films that determine the electrical and functional performance of organic devices. We studied aerosol jet printed lines of the PEDOT:PSS semiconductive polymer on flexible Kapton substrates. We choose the focus ratio, defined as the ratio between the sheath and carrier gas flow rates, as the main parameter that best characterizes the process and hence the characteristics of printed lines. A detailed analysis of the line width and thickness, as a function of the focus ratio and carrier gas flow for different nozzle sizes and sheath gas flow rates, is reported. The edge profile definition of printed PEDOT:PSS lines has been found to be affected by a combination of overspray, typical of aerosol deposition, and pinholes due to the Kapton/PEDOT:PSS interaction, while their core profile results to be almost defects free. An optimal printing window for different nozzle sizes has been determined in terms of a minimization of overspray/pinholes effects with respect to the whole line width. Finally, an array of whole-plastic, planar Organic Electrochemical Transistors, having both the channel and the gate electrode made of PEDOT:PSS, has been manufactured using the best combination of process parameters. Transistors have been characterized for different channel/gate area ratios and the transconductance analysed as a function of channel to gate area.

Rapid Prototyping (RP) promises to induce a revolutionary impact on how the objects can be produced and used in industrial manufacturing as well as in everyday life. Over the time a standard technique as the 3D Stereolithography (SL) has become a fundamental technology for RP and Additive Manufacturing (AM), since it enables the fabrication of the 3D objects from a cost-effective photocurable resin. Efforts to obtain devices more complex than just a mere aesthetic simulacre, have been spent with uncertain results. The multidisciplinary nature of such manufacturing technique furtherly hinders the route to the fabrication of complex devices. A good knowledge of the bases of material science and engineering is required to deal with SL technological, characterization and testing aspects. In this framework, our study aims to reveal a new approach to obtain RP of complex devices, namely Organic Electro-Chemical Transistors (OECTs), by SL technique exploiting a resin composite based on the conductive poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) and the photo curable Poly(ethylene glycol) diacrylate (PEGDA). A comprehensive study is presented, starting from the optimization of composite resin and characterization of its electrochemical properties, up to the 3D OECTs printing and testing. Relevant performances in biosensing for dopamine (DA) detection using the 3D OECTs are reported and discussed too.

Organic electrochemical transistors (OECTs) represent a powerful and versatile type of organic-based device, widely used in biosensing and bioelectronics due to potential advantages in terms of cost, sensitivity, and system integration. The benchmark organic semiconductor they are based on is poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS), the electrical properties of which are reported to be strongly dependent on film morphology and structure. In particular, the literature demonstrates that film processing induces morphostructural changes in terms of conformational rearrangements in the PEDOT:PSS in-plane phase segregation and out-of-plane vertical separation between adjacent PEDOT-rich domains. Here, taking into account these indications, we show the thickness-dependent operation of OECTs, contextualizing it in terms of the role played by PEDOT:PSS film thickness in promoting film microstructure tuning upon controlled-atmosphere long-lasting thermal annealing (LTA). To do this, we compared the LTA-OECT response to that of OECTs with comparable channel thicknesses that were exposed to a rapid thermal annealing (RTA). We show that the LTA process on thicker films provided OECTs with an enhanced amplification capability. Conversely, on lower thicknesses, the LTA process induced a higher charge carrier modulation when the device was operated in sensing mode. The provided experimental characterization also shows how to optimize the OECT response by combining the control of the microstructure via solution processing and the effect of postdeposition processing.

Modern sensing technologies are highly required for health monitoring. In this respect, the development of small‐size, high‐performance, and self‐powered biosensors for detecting and quantifying disease markers in biofluids can bring crucial changes and improvements to the concept of health monitoring systems. Clinical trials identify a wide range of biomarkers in biofluids that provide significant health information. Research into novel functional materials with outstanding properties opens up new perspectives for fabricating new‐generation biosensors. Furthermore, energy conversion and storage units are investigated to integrate them into biosensors and develop self‐powered systems. Electrochemical methods are very attractive for applications in biosensor technology, both in terms of biomarker detection and energy generation. Here the recent achievements in research into self‐powered electrochemical biosensors to detect sweat and saliva biomarkers are presented. Potential biomarkers for efficient analysis of these fluids are discussed in light of their importance in identifying various diseases. The influence of electrode materials on the performance of sensors is discussed. Progress in developing operating strategies for self‐powered electrochemical monitoring systems is also discussed. A summary and outlook are presented, mentioning major achievements and current issues to be explored.