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Silk and silk derivatives have emerged as a possible alternative in surgical device development, offering mechanical strength, biocompatibility, and environmental sustainability. Through a systematic review following PRISMA guidelines, this study evaluated silk fibroin's application across pre-clinical and clinical settings, focusing on its role as screws and plates for osteofixation. A comprehensive search yielded 245 studies, with 33 subjected to full-text review and 15 ultimately included for qualitative analysis. The findings underscore silk fibroin's superior properties, including its tunable degradation rates and ability to be functionalized with therapeutic agents. In vivo and in vitro studies demonstrated its efficacy in enhancing bone healing, offering improved outcomes in osteofixation, particularly for craniofacial defects. Silk fibroin's remarkable attributes in biodegradation and drug release capabilities underscore its potential to enhance patient care. Ultimately, silk fibroin's integration into surgical practices promises a revolution in patient outcomes and environmental sustainability. Its versatility, coupled with the continuous progress in fabrication techniques, signals a promising horizon for its widespread acceptance in the medical field, potentially establishing a new benchmark in surgical treatment. Further research is expected to solidify the transition of silk products from basic science to patient care, paving the way for widespread use in various surgical applications. [ABSTRACT FROM AUTHOR]

Spider silks are remarkable materials characterized by superb mechanical properties such as strength, extensibility, and lightweightedness. Yet, to date, limited models are available to fully explore sequence‐property relationships for analysis and design. Here a custom generative large‐language model is proposed to enable the design of novel spider silk protein sequences to meet complex combinations of target mechanical properties. The model, pretrained on a large set of protein sequences, is fine‐tuned on ≈1,000 major ampullate spidroin (MaSp) sequences for which associated fiber‐level mechanical properties exist, to yield an end‐to‐end forward and inverse generative approach that is aplied in a multi‐agent strategy. Performance is assessed through: 1) a novelty analysis and protein type classification for generated spidroin sequences through Basic Local Alignment Search Tool (BLAST) searches, 2) property evaluation and comparison with similar sequences, 3) comparison of resulting molecular structures, and 4) a detailed sequence motif analyses. This work generates silk sequences with property combinations that do not exist in nature and develops a deeper understanding of the mechanistic roles of sequence patterns in achieving overarching key mechanical properties (elastic modulus (E), strength, toughness, failure strain). The model provides an efficient approach to expand the silkome dataset, facilitating further sequence‐structure analyses of silks, and establishes a foundation for synthetic silk design and optimization. [ABSTRACT FROM AUTHOR]

Biocompatible and morphable hydrogels capable of multimode reprogrammable, and adaptive shape changes are potentially useful for diverse biomedical applications. However, existing morphable systems often rely on complicated structural designs involving cumbersome and energy-intensive fabrication processes. Here, we report a simple electric-field-activated protein network migration strategy to reversibly program silk-protein hydrogels with controllable and reprogrammable complex shape transformations. The application of a low electric field enables the convergence of net negatively charged protein cross-linking networks toward the anode (isoelectric point plane) due to the pH gradient generated in the process, facilitating the formation of a gradient network structure and systems suitable for three-dimensional shape change. These tunable protein networks can be reprogrammed or permanently fixed by control of the polymorphic transitions. We show that these morphing hydrogels are capable of conformally interfacing with biological tissues by programming the shape changes and a bimorph structure consisting of aligned carbon nanotube multilayers and the silk hydrogels was assembled to illustrate utility as an implantable bioelectronic device for localized low-voltage electrical stimulation of the sciatic nerve in a rabbit. [ABSTRACT FROM AUTHOR]

A variety of artificial silk spinning approaches are attempted to mimic the natural spinning process found in silkworms and spiders, yet instantaneous silk fiber formation with hierarchical structure under physiological and ambient conditions without post‐treatment procedures remains unaddressed. Here, this work reports a new strategy to fabricate silk protein‐based aerosols and silk fibers instantaneously in situ using a spray device, avoiding complicated and costly advanced manufacturing techniques. The key to success is the instantaneous conformational transition of silk fibroin from random coil to β‐sheet right before spraying by mixing silk and polyethylene glycol (PEG) solutions in the spray device, allowing aerosols and silk fibers to be sprayed, with further control achieved via the molecular weight of silk. The spinning process of the spray device is based on the use of green solvents, that is, all steps of instant conformational transition of silk fibroin are carried out in aqueous conditions or with buffers at ambient conditions, in combination with shear and elongational flow caused by the hydraulic pressure generated in the spray container. The system supports a portable and user‐friendly system that could be used for drug delivery carriers, wound coating materials, and rapid silk fiber conformal coatings on surfaces. [ABSTRACT FROM AUTHOR]

Continuous monitoring of biochemical analytes like oxygen is of interest in biomedicine to provide insight into physiology and health. Silk‐protein biomaterials are particularly useful as the scaffold material in oxygen sensors due to silk's unique amphiphilic chemistry, which promotes noncovalent stabilization of the protein and additives in aqueous environments. Silk films containing a water‐insoluble oxygen‐sensing chromophore, Pd (II) tetramethacrylated benzoporphyrin (PdBMAP), are evaluated as optical oxygen sensors in vitro and in vivo. These silk‐chromophore composites are stabilized by the self‐assembled, physically crosslinked protein network. The deaerated phosphorescence lifetime (τm,0 ≈300 µs) of the chromophore in vitro is quenched to 50% of its initial value at ≈31 µm dissolved oxygen, indicating sensing functionality within physiological ranges of oxygen. In vitro enzymatic degradation of the silk films with and without the chromophore is demonstrated. The silk‐chromophore composite films are cytocompatible in vitro, biocompatible in vivo upon implantation in rats, and displayed mechanical properties suitable for subcutaneous implantation. Further, the films maintain oxygen‐sensing function in vivo and demonstrate real‐time sensing capabilities throughout various physiological states (i.e., hyperoxia, normoxia, and hypoxia). [ABSTRACT FROM AUTHOR]

Regenerated silk fibers typically fall short of silkworm cocoon fibers in mechanical properties due to reduced fiber crystal structure and alignment. One approach to address this has been to employ inorganic materials as reinforcing agents. The present study avoids the need for synthetic additives, demonstrating the first use of exfoliated silk nanofibers to control silk solution crystallization, resulting in all‐silk pseudocomposite fibers with remarkable mechanical properties. Incorporating only 0.06 wt% silk nanofibers led to a ≈44% increase in tensile strength (over 600 MPa) and ≈33% increase in toughness (over 200 kJ kg−1) compared with fibers without silk nanofibers. These remarkable properties can be attributed to nanofiber crystal seeding in conjunction with fiber draw. The crystallinity nearly doubled from ≈17% for fiber spun from pure silk solution to ≈30% for the silk nanofiber reinforced sample. The latter fiber also shows a high degree of crystal orientation with a Herman's orientation factor of 0.93, a value which approaches that of natural degummed B. mori silk cocoon fiber (0.96). This study provides a strong foundation to guide the development of simple, eco‐friendly methods to spin regenerated silk with excellent properties and a hierarchical structure that mimics natural silk. [ABSTRACT FROM AUTHOR]

Versatile silk protein-based material formats were studied to demonstrate bioresorbable, implantable optical oxygen sensors that can integrate with the surrounding tissues. The ability to continuously monitor tissue oxygenation in vivo is desired for a range of medical applications. Silk was chosen as the matrix material due to its excellent biocompatibility, its unique chemistry that facilitates interactions with chromophores, and the potential to tune degradation time without altering chemical composition. A phosphorescent Pd (II) benzoporphyrin chromophore was incorporated to impart oxygen sensitivity. Organic solvent-based processing methods using 1,1,1,3,3,3-hexafluoro-2-propanol were used to fabricate: 1) silk-chromophore films with varied thickness and 2) silk-chromophore sponges with interconnected porosity. All compositions were biocompatible and exhibited photophysical properties with oxygen sensitivities (i.e., Stern-Volmer quenching rate constants of 2.7–3.2 × 104 M−1) useful for monitoring physiological tissue oxygen levels and for detecting deviations from normal behavior (e.g., hyperoxia). The potential to tune degradation time without significantly impacting photophysical properties was successfully demonstrated. Furthermore, the ability to consistently monitor tissue oxygenation in vivo was established via a multi-week rodent study. Histological assessments indicated successful tissue integration for the sponges, and this material format responded more quickly to various oxygen challenges than the film samples. [Display omitted] • Bioresorbable, tissue oxygen sensors made of silk and Pd (II) benzoporphyrin • Non-porous films and sponges fabricated using organic solvent processing methods • Photophysical properties offer good interpretability and dynamic range • Sponges exhibit interconnected porosity and excellent tissue integration • Sponges offered consistent performance to external stimuli during in vivo rat study [ABSTRACT FROM AUTHOR]

Recombinant spider silk materials with antimicrobial peptides are a promising new class of drug-free antimicrobial materials capable of preventing surgical site infections (SSI), but their potential to impede infections is unclear. Herein, we aimed to unravel the biological and inflammatory potential of bioengineered spider silk materials to prevent SSI using an infection animal model. Silk-like fibers made of silk fibroin and spider silk proteins with antimicrobial peptides (6mer-HNP1) held improved stiffness (2.9 GPa) and had a slow biodegradation profile while inhibiting bacterial adherence in vitro by 5-log and 6-log reduction on Methicillin-Resistant Staphylococcus aureus (MRSA) and Escherichia coli (E. coli), respectively. In vivo studies showed that fibers with 6mer-HNP1 elicited a short-term low to mild local inflammatory response, similar to implanted commercial sutures. In the presence of a bacterial infection, the mediators related to infection and inflammation were downregulated suggesting that the fibers maintained a low but active response to bacterial infection. Thus, the presence of 6mer-HNP1 helped the host maintain an active response to bacterial infection, impairing the development of an acute infection. Our findings further support the use of bioengineered spider silk proteins to develop drug-free antimicrobial sutures capable to impair SSI. [ABSTRACT FROM AUTHOR]