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Addressing peripheral nerve defects remains a significant challenge in regenerative neurobiology. Autografts emerged as the gold-standard management, however, are hindered by limited availability and potential neuroma formation. Numerous recent studies report the potential of wireless electronic system for nerve defects repair. Unfortunately, few has met clinical needs for inadequate electrode precision, poor nerve entrapment and insufficient bioactivity of the matrix material. Herein, we present an advanced wireless electrical nerve stimulator, based on water-responsive self-curling silk membrane with excellent bioabsorbable and biocompatible properties. We constructed a unique bilayer structure with an oriented pre-stretched inner layer and a general silk membrane as outer layer. After wetting, the simultaneous contraction of inner layer and expansion of outer layer achieved controllable super-contraction from 2D flat surface to 3D structural reconfiguration. It enables shape-adaptive wrapping to cover around nerves, overcomes the technical obstacle of preparing electrodes on the inner wall of the conduit, and prevents electrode breakage caused by material expansion in water. The use of fork capacitor-like metal interface increases the contact points between the metal and the regenerating nerve, solving the challenge of inefficient and rough electrical stimulation methods in the past. Newly developed electronic stimulator is effective in restoring 10 mm rat sciatic nerve defects comparable to autologous grafts. The underlying mechanism involves that electric stimulation enhances anterograde mitochondrial transport to match energy demands. This newly introduced device thereby demonstrated the potential as a viable and efficacious alternative to autografts for enhancing peripheral nerve repair and functional recovery.

Ciliary neurotrophic factor (CNTF) acts as a potent neuroprotective agent in neuronal survival and regeneration, and can also induce the differentiation of several stem cells into neurons, which highlights the broad application of CNTF in biomedicine. However, large‐scale production of bioactive recombinant human CNTF protein remains to be explored. Herein, this study aims to express a bioactive human CNTF protein on a large scale by genetically engineering a silk gland bioreactor of silkworm. Our results showed that CNTF protein was successfully expressed in the middle silk gland (MSG) of silkworm, which can be secreted into the silks with the amount of 3.2 mg/g cocoons. The fabrication of human CNTF‐functionalized silk material was able to promote proliferation and migration of neural cells when compared to the natural silk protein. Importantly, this functional silk material could also facilitate neurite outgrowth of mouse retinal ganglion cell (RGC‐5) cells. All these data demonstrated a high bioactivity of the recombinant human CNTF protein expressed in the MSG of silkworm. The further fabrication of different silk materials with CNTF bioactivity will give biomedical applications in tissue engineering and neuroregeneration. [ABSTRACT FROM AUTHOR]

The revolutionary and pioneering advancements of silk materials in recent years have provided numerous opportunities for the great trend of sustainable green energy. Working as an eco‐friendly replacement for conventional energy harvester or storage device, silk‐based energy sources that get intensive attention are regarded as new solutions in flexible human‐integrated applications. Compared with other synthetic polymers, silk materials present outstanding biocompatibility, biodegradability, and many other attractive properties owing to the natural protein composition, various modification methods, large‐scale green production, and superior fabrication techniques. Herein, recent progress and ongoing challenges posed by the utilization and translation of silk materials in green energy application are discussed.

Neuroblastoma is the most common extracranial childhood solid tumor. Treatment of high risk tumors require intense multicycle chemotherapies, resulting in short- and long-term toxicities. Here, we present treatment of an orthotopic neuroblastoma mouse model, with silk fibroin materials loaded with vincristine, doxorubicin or the combination as a intratumoral, sustained release system. The materials, loaded with vincristine with or without doxorubicin, significantly decreased neuroblastoma tumor growth compared to materials loaded without drug or doxorubicin only as well as intravenous (IV) drug treatment. The intratumoral drug concentration was significantly higher with intratumoral delivery versus IV. Furthermore, intratumor delivery decreased the maximum plasma concentration compared to IV delivery, reducing systemic exposure and possibly reduing long-term side effects of chemotherapy exposure. Histopathologically, tumors with remission periods >25 days before recurrence transformed from a 'small-round-blue cell' (SBRC) to predominantly 'large cell' neuroblastoma (LCN) histopathology, a more aggressive tumor subtype with unfavorable clinical outcomes. These results show that intratumoral chemotherapy delivery may be a treatment strategy for pediatric neuroblastoma, potentially translatable to other focal tumors types. Furthermore, this treatment modality allows for a clinically relevant mouse model of tumor transformation that may be used for studying the phenotypical tumor recurrence and developing more effective treatment strategies for recurrent tumors. [ABSTRACT FROM AUTHOR]

As a substitute for traditional disposable paper, rewritable paper has been widely studied in recent years because of its low consumption. However, it is still a major challenge for rewritable paper to meet the requirements of simple large-area preparation, biocompatibility, good cycle stability and multi-color output. In this study, a new type of rewritable paper with silk-fibroin inverse photonic glass (SF-IPG paper) is developed. The simple spray coating method is used to realize the rapid and large-area preparation of it. Based on the regulation of the structure of inverse photonic glass, through the dynamic hydrogen bonding between H 2 O and silk fibroin polymer chains, the multi-color text output of SF-IPG paper written with a water pen is realized. SF-IPG paper has good mechanical strength, excellent biocompatibility, high structural stability and unique water response mechanism. At the same time, it is simple to produce, fully meets the requirements of environmental protection and sustainable development. Therefore, this preparation strategy has broad application prospects in the field of rewritable paper. • The hierarchical control of the microstructure of silk fibroin films is realized, and the mechanisms of structural transformation is first put forward. • Inverse photonic glass structure with hard to copy characteristics is first applied to rewritable paper. • The spray coating method is used to make the rewritable paper, which lays a foundation for the industrial scale production. • The rewritable paper exhibits good mechanical strength, high structural stability and rich optical modes. [ABSTRACT FROM AUTHOR]

Cardiovascular diseases are one of the leading causes of death globally. Among various cardiovascular diseases, myocardial infarction is an important one. Compared with conventional treatments, cardiac tissue engineering provides an alternative to repair and regenerate the injured tissue. Among various types of materials used for tissue engineering applications, silk biomaterials have been increasingly utilized due to their biocompatibility, biological functions, and many favorable physical/chemical properties. Silk biomaterials are often used alone or in combination with other materials in the forms of patches or hydrogels, and serve as promising delivery systems for bioactive compounds in tissue engineering repair scenarios. This review focuses primarily on the promising characteristics of silk biomaterials and their recent advances in cardiac tissue engineering., (© 2020 Wiley‐VCH GmbH.)

Many postsurgical complications stem from bacteria colony formation on the surface of implants, but the usage of antibiotic agents may cause antimicrobial resistance. Therefore, there is a strong demand for biocompatible materials with an intrinsic antibacterial resistance not requiring extraneous chemical agents. In this study, homogeneous nanocones were fabricated by oxygen plasma etching on the surface of natural, biocompatible Bombyx mori silk films. The new hydroxyl bonds formed on the surface of the nanopatterned film by plasma etching increased the surface energy by around 176%. This hydrophilic nanostructure reduced the bacterial attachment by more than 90% for both Gram-negative ( Escherichia coli ) and Gram-positive ( Staphylococcus aureus ) bacteria and at the same time improved the proliferation of osteoblast cells by 30%. The nanoengineered substrate and pristine silk were cultured for 6 h with three different bacteria concentrations of 10 7 , 10 5 , and 10 3 CFU mL -1 and the cell proliferation on the nanopatterned samples was significantly higher due to limited bacteria attachment and prevention of biofilm formation. The concept and materials described here reveal a promising alternative to produce biomaterials with an inherent biocompatibility and bacterial resistance simultaneously to mitigate postsurgical infections and minimize the use of antibiotics.

Silk is a natural fiber renowned for its outstanding mechanical properties that have enabled the manufacturing of ultralight and ultrastrong textiles. Recent advances in silk processing and manufacturing have underpinned a re-interpretation of silk from textiles to technological materials. Here, it is argued that silk materials-optimized by selective pressure to work in the environment at the biotic-abiotic interface-can be harnessed by human micro- and nanomanufacturing technology to impart new functionalities and opportunities. A critical overview of recent progress in silk technology is presented with emphasis on high-tech applications enabled by recent innovations in multilevel modifications, multiscale manufacturing, and multimodal characterization of silk materials. These advances have enabled successful demonstrations of silk materials across several disciplines, including tissue engineering, drug delivery, implantable medical devices, and biodissolvable/degradable devices., (© 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)