A Comparative Study on the Dissolution of Argema mimosae Silk Fibroin and Fabrication of Films and Nanofibers

Injectable silk fibroin peptide nanofiber hydrogel composite scaffolds for cartilage regeneration

Transforming growth factor-β1 (TGF-β1) is essential for cartilage regeneration, but its susceptibility to enzymatic denaturation and high cost limit its application. Herein, we report Ac-LIANAKGFEFEFKFK-NH2 (LKP), a self-assembled peptide nanofiber hydrogel that can mimic the function of TGF-β1. The LKP hydrogel is simple to synthesize, and in vitro experiments confirmed its good biocompatibility and cartilage-promoting ability. However, LKP hydrogels suffer from poor mechanical properties and are prone to fragmentation; therefore, we prepared a series of injectable hydrogel composite scaffolds (SF-GMA/LKP) by combining LKP with glycidyl methacrylate (GMA)-modified silk fibroin (SF). SF-GMA/LKP composite scaffolds instantaneously induced in-situ filling of cartilage defects and, at the same time, relied on the interaction between LKP and SF-GMA interaction to prolong the duration of action of LKP. The SF-GMA/LKP10 and SF-GMA/LKP20 composite scaffolds had the best effect on neocartilage and subchondral bone reconstruction. This composite hydrogel scaffold can be used for high-quality cartilage repair.

Biomimetic Spun Silk Ionotronic Fibers for Intelligent Discrimination of Motions and Tactile Stimuli

Innovation in the ionotronics field has significantly accelerated the development of ultraflexible devices and machines. However, it is still challenging to develop efficient ionotronic-based fibers with necessary stretchability, resilience, and conductivity due to inherent conflict in producing spinning dopes with both high polymer and ion concentrations and low viscosities. Inspired by the liquid crystalline spinning of animal silk, this study circumvents the inherent tradeoff in other spinning methods by dry spinning a nematic silk microfibril dope solution. The liquid crystalline texture allows the spinning dope to flow through the spinneret and form free-standing fibers under minimal external forces. The resultant silk-sourced ionotronic fibers (SSIFs) are highly stretchable, tough, resilient, and fatigue-resistant. These mechanical advantages ensure a rapid and recoverable electromechanical response of SSIFs to kinematic deformations. Further, the incorporation of SSIFs into core-shell triboelectric nanogenerator fibers provides outstanding stable and sensitive triboelectric response to precisely and sensitively perceive small pressures. Moreover, by implementing a combination of machine learning and Internet of Things techniques, the SSIFs can sort objects made of different materials. With these structural, processing, performance, and functional merits, the SSIFs prepared herein are expected to be applied in human-machine interfaces.

Advances in Preparation and Properties of Regenerated Silk Fibroin

Over the years, silk fibroin (SF) has gained significant attention in various fields, such as biomedicine, tissue engineering, food processing, photochemistry, and biosensing, owing to its remarkable biocompatibility, machinability, and chemical modifiability. The process of obtaining regenerated silk fibroin (RSF) involves degumming, dissolving, dialysis, and centrifugation. RSF can be further fabricated into films, sponges, microspheres, gels, nanofibers, and other forms. It is now understood that the dissolution method selected greatly impacts the molecular weight distribution and structure of RSF, consequently influencing its subsequent processing and application. This study comprehensively explores and summarizes different dissolution methods of SF while examining their effects on the structure and performance of RSF. The findings presented herein aim to provide valuable insights and references for researchers and practitioners interested in utilizing RSF in diverse fields.

Evaluating the Performance of Ball-Milled Silk Fibroin Films for Simultaneous Adsorption of Eight Pharmaceuticals from Water

Pollutants mainly exist as multicomponent mixtures in the environment. Therefore, it is necessary to synthesize low-cost adsorbents that can simultaneously adsorb multiple compounds. This work presents the prospect of the adsorption of multiclass pharmaceuticals from the aqueous environment using an adsorbent derived from silk fibroin of the wild silkworm Argema mimosae. The adsorbent was prepared by dissolving degummed silk fibroin and the resultant solution was cast to obtain films that were ball-milled to powder. FTIR results revealed bands corresponding to N-H and C=O stretching vibrations. Particle size distribution data generally showed two size groups in the range of 50-90 nm and 250-625 nm. The study focused on the adsorptive removal of multiple compounds consisting of eight pharmaceuticals representing various classes including a β-blocker (pindolol), anesthetic (lidocaine), stimulant (caffeine), antiviral (nevirapine), steroid (estriol), anti-epileptic (carbamazepine), and a non-steroidal anti-inflammatory drug (naproxen). The adsorption process was best fitted to the pseudo-second-order isotherm and an overall match to the Freundlich model. Thermodynamic parameters suggested that the process was mainly exothermic and more spontaneous at lower temperatures. The performance of the adsorbent was further evaluated using environmental waters and the adsorbent demonstrated good potential for simultaneous adsorption of multicomponent pharmaceuticals.