An artificial liquid-liquid phase separation-driven silk fibroin-based adhesive for rapid hemostasis and wound sealing.

The powerful adhesion systems of marine organisms have inspired the development of artificial protein-based bioadhesives. However, achieving robust wet adhesion using artificial bioadhesives remains technically challenging because the key element of liquid-liquid phase separation (LLPS)-driven complex coacervation in natural adhesion systems is often ignored. In this study, mimicking the complex coacervation phenomenon of marine organisms, an artificial protein-based adhesive hydrogel (SFG hydrogel) was developed by adopting the LLPS-mediated coacervation of the natural protein silk fibroin (SF) and the anionic surfactant sodium dodecylbenzene sulfonate (SDBS).

Silk fibroin-based hemostatic powders with instant and robust adhesion performance for sutureless sealing of gastrointestinal defects.

Powder-based hemostatic technology has offered unprecedented opportunities in surgical sealing and repair of irregularly shaped and noncompressible wounds. Despite their routine use, existing clinical hemostatic powders are challenged either by poor mechanical properties or inadequate adhesion to bleeding tissues in biological environments. Here, inspired by the mussel foot proteins' fusion assembly strategy, a novel silk fibroin-based hemostatic powder (named as SF/PEG/TA) with instant and robust adhesion performance is developed.

A disulfide molecule-vancomycin nanodrug delivery system efficiently eradicates intracellular bacteria.

Intracellular bacteria often lead to chronic and recurrent infections; however, most of the known antibiotics have poor efficacy against intracellular bacteria due to their poor cell membrane penetration efficiency into the cytosol. Here, a thiol-mediated nanodrug delivery system, named Van-DM NPs, was developed to improve vancomycin's penetration efficiency and intracellular antibacterial activities. Van-DM NPs were prepared through self-assembly of vancomycin (Van) and the disulfide molecule (DM) in NaOH buffer solution.

Natural polymer-based bioadhesives as hemostatic platforms for wound healing.

Medical adhesives are advanced but challenging alternatives to wound closure and repair, especially in mitigating uncontrolled hemorrhage. Ideal hemostatic adhesives need to meet good biocompatibility and biodegradability, adequate mechanical strength, and strong tissue adhesion functionality under wet and dynamic conditions. Considering these requirements, natural polymers such as polysaccharide, protein and DNA, attract great attention as candidates for making bioadhesives because of their distinctive physicochemical performances and biological properties.

Biomimetic multifunctional hybrid sponge via enzymatic cross-linking to accelerate infected burn wound healing.

Preparing sponge dressings with stable wet adhesion remains difficult in wound repair, especially in burn wounds with bleeding and large amounts of exudate. In this work, a multifunctional hybrid sponge dressing (DHGT+PHMB+TiONPs) with good wet adhesion was developed by combining biomimetic and enzymatic cross-linking reactions. The sponge dressing matrix (DHGT) was prepared by tyrosinase-catalyzed cross-linking of dopamine-modified hyaluronic acid (DOPA-HA) and gelatin.

Silk Fibroin-Based Tough Hydrogels with Strong Underwater Adhesion for Fast Hemostasis and Wound Sealing.

Rapid and strong adhesion of hydrogel adhesives is required for instant wound closure and hemostasis. However, in situ hydrogel formation and sufficient adhesion at target tissue sites in biological environments are severely compromised by the presence of blood and body fluids. In this work, an underwater adhesive hydrogel (named SHCa) is fabricated with rapid in situ gelation, enhanced mechanical toughness, and robust underwater adhesion.

Advanced bioactive hydrogels for the treatment of myocardial infarction.

Myocardial infarction (MI) is the leading cause of cardiovascular disease-related deaths. Local ischemia and cardiomyocyte death lead to a series of pathological remodeling events of the infarcted extracellular matrix (ECM) that are significantly different from normal cardiac tissues. These pathological characteristics have inspired the development of microenvironment-responsive therapeutic strategies for MI.

A mussel-inspired supramolecular hydrogel with robust tissue anchor for rapid hemostasis of arterial and visceral bleedings.

In recent years, the developed hemostatic technologies are still difficult to be applied to the hemostasis of massive arterial and visceral hemorrhage, owing to their weak hemostatic function, inferior wet tissue adhesion, and low mechanical properties. Herein, a mussel-inspired supramolecular interaction-cross-linked hydrogel with robust mechanical property (308.47 ± 29.

High-Strength and High-Toughness Silk Fibroin Hydrogels: A Strategy Using Dynamic Host-Guest Interactions.

Natural polymer-based hydrogels attract great attention because of their inherent biocompatibility and controllable biodegradability. However, the broad applications of these hydrogels require a combination of high mechanical strength, high toughness, fatigue resistance, as well as self-healing. The integration of this combination into one natural polymer-based hydrogel remains challenging.

Biologically Responsive Plasmonic Assemblies for Second Near-Infrared Window Photoacoustic Imaging-Guided Concurrent Chemo-Immunotherapy.

We developed dual biologically responsive nanogapped gold nanoparticle vesicles loaded with immune inhibitor and carrying an anticancer polymeric prodrug for synergistic concurrent chemo-immunotherapy against primary and metastatic tumors, along with guided cargo release by photoacoustic (PA) imaging in the second near-infrared (NIR-II) window. The responsive vesicle was prepared by self-assembly of nanogapped gold nanoparticles (AuNNPs) grafted with poly(ethylene glycol) (PEG) and dual pH/GSH-responsive polyprodug poly(SN--4-vinylpyridine) (termed AuNNP@PEG/PSNVP), showing intense PA signal in the NIR-II window. The effect of the rigidity of hydrophobic polymer PSNVP on the assembled structures and the formation mechanism of AuNNP@SN Ve were elucidated by computational simulations.

Water-Based Black Phosphorus Hybrid Nanosheets as a Moldable Platform for Wound Healing Applications.

Black phosphorus (BP) nanosheets with unique biocompatibility and superior optical performance have attracted enormous attention in material science. However, their instability and poor solution-processability severely limit their clinical applications. In this work, we demonstrate the use of silk fibroin (SF) as an exfoliating agent to produce thin-layer BP nanosheets with long-term stability and facile solution-processability.

A black phosphorus nanosheet-based siRNA delivery system for synergistic photothermal and gene therapy.

Gene therapy with small interfering RNA (siRNA) has been proved to be a promising technology to treat various diseases by hampering the production of target proteins. However, developing a delivery system that has high efficiency in transporting siRNA without obvious side effects remains a challenge. Herein, we designed a new survivin siRNA delivery system based on polyethyleneimine functionalized black phosphorus (BP) nanosheets which could suppress tumor growth by silencing survivin expression.

Silk fibroin-assisted exfoliation and functionalization of transition metal dichalcogenide nanosheets for antibacterial wound dressings.

Two-dimensional transition metal dichalcogenides (TMDs) have attracted rapidly increasing attention due to their fascinating properties and potential applications. However, scalable and cost-effective methods to produce thin-layer TMD nanosheets and their functional composites with environmental benignity are still limited. Herein, we develop a facile and environmentally friendly method for the scalable production of thin-layer TMD nanosheets in an aqueous medium by using silk fibroin, a natural and abundant biopolymer, as the exfoliating agent.

Monodisperse phase transfer and surface bioengineering of metal nanoparticles via a silk fibroin protein corona.

Uniform hydrophobic nanoparticles synthesized in nonpolar solvents possess excellent physio-chemical properties, showing great potential in biomedical applications. However, the presence of hydrophobic ligands on their surfaces limits their use under physiological conditions. Inspired by protein coronas present at the nano-bio interface, here we report a facile and universal method for phase transfer and surface bioengineering of hydrophobic nanoparticles using β-sheet-rich silk fibroin, a FDA-approved natural protein.

Silk scaffolds with tunable mechanical capability for cell differentiation.

Bombyx mori silk fibroin is a promising biomaterial for tissue regeneration and is usually considered an "inert" material with respect to actively regulating cell differentiation due to few specific cell signaling peptide domains in the primary sequence and the generally stiffer mechanical properties due to crystalline content formed in processing. In the present study, silk fibroin porous 3D scaffolds with nanostructures and tunable stiffness were generated via a silk fibroin nanofiber-assisted lyophilization process. The silk fibroin nanofibers with high β-sheet content were added into the silk fibroin solutions to modulate the self-assembly, and to directly induce water-insoluble scaffold formation after lyophilization.

Silk Nanofiber Hydrogels with Tunable Modulus to Regulate Nerve Stem Cell Fate.

Reconstruction of damaged nerves remains a significant unmet challenge in clinical medicine. To foster improvements, the control of neural stem cell (NSC) behaviors, including migration, proliferation and differentiation are critical factors to consider. Topographical and mechanical stimulation based on the control of biomaterial features is a promising approach, which are usually studied separately.

Osteoinductive-nanoscaled silk/HA composite scaffolds for bone tissue engineering application.

Osteoinductive silk/hydroxyapatite (HA) composite scaffolds for bone regeneration were prepared by combining silk with HA/silk core-shell nanoparticles. The HA/silk nanoparticles were directly dispersed in silk solution to form uniform silk/HA blend and then composite scaffolds after a freeze-drying process. The HA/silk nanoparticles uniformly distributed in silk scaffolds at nanometer scale at varying HA content up to 40%, and substantially improved the compressive strength of the scaffolds produced.

Reversible hydrogel-solution system of silk with high beta-sheet content.

Silkworm silk has been widely used as a textile fiber, as biomaterials and in optically functional materials due to its extraordinary properties. The β-sheet-rich natural nanofiber units of about 10-50 nm in diameter are often considered the origin of these properties, yet it remains unclear how silk self-assembles into these hierarchical structures. A new system composed of β-sheet-rich silk nanofibers about 10-20 nm in diameter is reported here, where these nanofibers formed into "flowing hydrogels" at 0.

Nanoscale Control of Silks for Nanofibrous Scaffold Formation with Improved Porous Structure.

Silk-based porous scaffolds have been used extensively in tissue engineering because of their excellent biocompatibility, tunable biodegradability and robust mechanical properties. Although many silk-based scaffolds have been prepared through freeze-drying, a challenge remains to effectively control porous structures during this process. In the present study silk fibroin with different nanostructures were self-assembled in aqueous solution by repeated drying-dissolving process and then used to improve porous structure formation in lyophilization process.

Molecular detection of Penicillium griseofulvum as the coastal pollution indicator.

Molecular methods were carried out to detect Penicillium griseofulvum, a dominant species related to heavy metal pollution, which was screened from marine contaminated sediments. Based on differences in internal transcribed spacer (ITS) sequences of Penicillium genus and specific isoamyl alcohol oxidase (IAO) sequences, species-specific primers AS1/RS4 and IAO1/IAO2 of Penicillium griseofulvum were designed and synthesized which were then employed in optimized PCR systems. The detection sensitivities were compared through ordinary PCR and nested-PCR using two pairs of primers, respectively.

[Molecular detection of Penicillium griseofulvum as the coastal pollution indicator].

Objective: PCR method was used to detect Penicillium griseofulvum, a dominant species in marine contaminated sediments and thereby to deduce the contamination degree.

Methods: According to differences in internal transcribed space (ITS) sequences of Penicillium genus and specific IAO sequence, we designed species-specific primers AS1/RS4 and IAO1/IAO2 of Penicillium griseofulvum and established the corresponding PCR systems. By using PCR and nested-PCR, the detection sensitivity was compared.