Charge-selective recognition at fibroin-modified electrodes for analytical application

Multisensor Systems and Arrays for Medical Applications Employing Naturally-Occurring Compounds and Materials

The significant improvement of quality of life achieved over the last decades has stimulated the development of new approaches in medicine to take into account the personal needs of each patient. Precision medicine, providing healthcare customization, opens new horizons in the diagnosis, treatment and prevention of numerous diseases. As a consequence, there is a growing demand for novel analytical devices and methods capable of addressing the challenges of precision medicine. For example, various types of sensors or their arrays are highly suitable for simultaneous monitoring of multiple analytes in complex biological media in order to obtain more information about the health status of a patient or to follow the treatment process. Besides, the development of sustainable sensors based on natural chemicals allows reducing their environmental impact. This review is concerned with the application of such analytical platforms in various areas of medicine: analysis of body fluids, wearable sensors, drug manufacturing and screening. The importance and role of naturally-occurring compounds in the development of electrochemical multisensor systems and arrays are discussed.

Protein-Based Bioelectronics

The desire for flexible electronics is booming, and development of bioelectronics for health monitoring, internal body procedures, and other biomedical applications is heavily responsible for the growing market. Most current fabrication techniques for flexible bioelectronics, however, do not use materials that optimize both biocompatibility and mechanical properties. This Review explores flexible electronic technologies, fabrication methods, and protein materials for biomedical applications. With favorable sustainability and biocompatibility, naturally derived proteins are an exceptional alternative to synthetic materials currently used. Many proteins can take on various forms, such as fibers, films, and scaffolds. The fabrication of resistors and organic solar cells on silk has already been proven, and optoelectronics made of collagen and keratin have also been explored. The flexibility and biocompatibility of these materials along with their proven performance in electronics make them ideal materials in the advancement of biomedical devices.

Aligned SF/P(LLA-CL)-blended nanofibers encapsulating nerve growth factor for peripheral nerve regeneration

Artificial nerve guidance conduits (NGCs) containing bioactive neurotrophic factors and topographical structure to biomimic native tissues are essential for efficient regeneration of nerve gaps. In this study, aligned SF/P(LLA-CL) nanofibers encapsulating nerve growth factor (NGF), which was stabilized by SF in core, were fabricated via a coaxial electrospinning technique. The controlled release of NGF from the nanofibers was evaluated using enzyme-linked immune sorbent assay (ELISA) and PC12 cell-based bioassay over a 60-day time period. The results demonstrated that NGF presented a sustained release and remained biological activity over 60 days. Nerve guidance conduits (NGCs) were fabricated by reeling the aligned SF/P(LLA-CL) nanofibrous scaffolds encapsulating NGF and then used as a bridge implanted across a 15-mm defect in the sciatic nerve of rats to promote nerve regeneration. The outcome in terms of regenerated nerve at 12 weeks was evaluated by a combination of electrophysiological assessment, histochemistry, and electron microscopy. All results clarified that the NGF-encapsulated-aligned SF/P(LLA-CL) NGCs promoted peripheral nerve regeneration significantly better than the aligned SF/P(LLA-CL) NGCs, suggesting that the released NGF from nanofibers could effectively promote the regeneration of peripheral nerve.

Insulin-like growth factor I releasing silk fibroin scaffolds induce chondrogenic differentiation of human mesenchymal stem cells

Growth factor releasing scaffolds are an emerging alternative to autologous or allogenous implants, providing a biologically active template for tissue (re)-generation. The goal of this study is to evaluate the feasibility of controlled insulin-like growth factor I (IGF-I) releasing silk fibroin (SF) scaffolds in the context of cartilage repair. The impact of manufacturing parameters (pH, methanol treatment and drug load) was correlated with IGF-I release kinetics using ELISA and potency tests. Methanol treatment induced water insolubility of SF scaffolds, allowed the control of bioactive IGF-I delivery and did not affect IGF-I potency. The cumulative drug release correlated linearly with the IGF-I load. To evaluate the chondrogenic potential of the scaffolds, hMSC were seeded on unloaded and IGF-I loaded scaffolds in TGF-beta supplemented medium. Chondrogenic differentiation of hMSC was observed on IGF-I loaded scaffolds, starting after 2 weeks and more strongly after 3 weeks, whereas no chondrogenic responses were observed on unloaded control scaffolds. IGF-I loaded porous SF scaffolds have the potential to provide chondrogenic stimuli to hMSC. Evidence for in vivo cartilage (re)generation must be demonstrated by future, pre-clinical proof of concept studies.