A Viscous-Biofluid Self-Pumping Organohydrogel Dressing to Accelerate Diabetic Wound Healing.

Viscous biofluids on wounds challenge conventional "water-absorbing" wound dressings in efficient drainage due to their poor fluidity, generally causing prolonged inflammation, anti-angiogenesis, and delayed wound closure. Herein, it is reported that a self-pumping organohydrogel dressing (SPD) with aligned hydrated hydrogel channels, prepared by a three-dimensional-templated wetting-enabled-transfer (3D-WET) polymerization process, can efficiently drain viscous fluids and accelerate diabetic wound healing. The asymmetric wettability of the hydrophobic-hydrophilic layers and aligned hydrated hydrogel channels enable unidirectional and efficient drainage of viscous fluids away from the wounds, preventing their overhydration and inflammatory stimulation.

A Rapid Self-Pumping Organohydrogel Dressing with Hydrophilic Fractal Microchannels to Promote Burn Wound Healing.

Burn wounds pose great challenges for conventional dressings because massive exudates oversecreted from swollen tissues and blisters seriously delay wound healing. Herein, a self-pumping organohydrogel dressing with hydrophilic fractal microchannels is reported that can rapidly drain excessive exudates with ≈30 times enhancement in efficiency compared with the pure hydrogel, and effectively promote burn wound healing. A creaming-assistant emulsion interfacial polymerization approach is proposed to create the hydrophilic fractal hydrogel microchannels in the self-pumping organohydrogel through a dynamic floating-colliding-coalescing process of organogel precursor droplets.

An enhanced fractal self-pumping dressing with continuous drainage for accelerated burn wound healing.

Massive exudates oversecreted from burn wounds always delay the healing process, accompanied by undesired adhesion, continuous inflammation, and high infection risk. Conventional dressings with limited draining ability cannot effectively remove the excessive exudates but constrain them in the wetted dressings immersing the wound bed. Herein, we fabricate an enhanced fractal self-pumping dressing by floating and accumulating hollow glass microspheres in the hydrogel precursor, that can continuously drain water at a non-declining high speed and effectively promote burn wound healing.

Self-Pumping Janus Hydrogel with Aligned Channels for Accelerating Diabetic Wound Healing.

Excessive exudate secreted from diabetic wounds often results in skin overhydration, severe infections, and secondary damage upon dressing changes. However, conventional wound dressings are difficult to synchronously realize the non-maceration of wound sites and rapid exudate transport due to their random porous structure. Herein, a self-pumping Janus hydrogel with aligned channels (JHA) composed of hydrophilic poly (ethylene glycol) diacrylate (PEGDA) hydrogel layer and hydrophobic polyurethane (PU)/graphene oxide (GO)/polytetrafluoroethylene (PTFE) layer is designed to rapidly export exudate and accelerate diabetic wound healing.

Polymer-Assisted Metallization of Mammalian Cells.

Developing biotemplating techniques to translate microorganisms and cultured mammalian cells into metallic biocomposites is of great interest for biosensors, electronics, and energy. The metallization of viruses and microbial cells is successfully demonstrated via a genetic engineering strategy or electroless deposition. However, it is difficult to transform mammalian cells into metallic biocomposites because of the complicated genes and the delicate morphological features.

A Spider-Silk-Inspired Wet Adhesive with Supercold Tolerance.

Conventional adhesives often encounter interfacial failure in humid conditions due to small droplets of water condensed on surface, but spider silks can capture prey in such environment. Here a robust spider-silk-inspired wet adhesive (SA) composed of core-sheath nanostructured fibers with hygroscopic adhesive nanosheath (poly(vinylpyrrolidone)) and supporting nanocore (polyurethane) is reported. The wet adhesion of the SA is achieved by a unique dissolving-wetting-adhering process of core-sheath nanostructured fibers, revealed by in situ observations at macro- and microscales.

Bioinspired Ultrafast-Responsive Nanofluidic System for Ion and Molecule Transport with Speed Control.

The design of an intelligent nanofluidic system for regulating the transport of substances such as ions and molecules is significant for applications in biological sensing, drug delivery, and energy harvesting. However, the existing nanofluidic system faces challenges in terms of an uncontrollable transport speed for molecules and ions and also a complex preparation processes, low durability, and slow response rate. Herein, we demonstrate the use of a bioinspired ferrofluid-based nanofluid that can facilitate multilevel ultrafast-responsive ion and molecule transport with speed control.

Bioinspired Janus Textile with Conical Micropores for Human Body Moisture and Thermal Management.

Excessive sweat secreted from the skin often causes undesired adhesion from wetted textiles and cold sensations. Traditional hydrophilic textiles such as cotton can absorb sweat but retain it. A hydrophobic/superhydrophilic Janus polyester/nitrocellulose textile embedded with a conical micropore array with a hydrophilic inner surface that can achieve directional liquid transport (with an ultrahigh directional water transport capability of 1246%) and maintain human body temperature (2-3 °C higher than with cotton textiles) is demonstrated.

Skin Adhesives with Controlled Adhesion by Polymer Chain Mobility.

Wearable devices have attracted a lot of attention because of their importance in the biomedical and electronic fields. However, as one of the important fixing materials, skin adhesives with controlled adhesion are often ignored. Although remarkable progress has been achieved in revealing the natural adhesion mechanism and biomimetic materials to complex solid surfaces, it remains a great challenge to explore nonirritant, controlled skin adhesives without surface structure.

A Self-Pumping Dressing for Draining Excessive Biofluid around Wounds.

Excessive biofluid around wounds often causes infection and hinders wound healing. However, the intrinsic hydrophilicity of the conventional dressing inevitably retains excessive biofluid at the interface between the dressing and the wound. Herein, a self-pumping dressing is reported, by electrospinning a hydrophobic nanofiber array onto a hydrophilic microfiber network, which can unidirectionally drain excessive biofluid away from wounds and finally accelerate the wound healing process.

A bio-inspired high strength three-layer nanofiber vascular graft with structure guided cell growth.

Human natural blood vessels have a three-layer structure including the tunica intima, tunica media, and tunica adventitia. These subtle structures endow healthy blood vessels with outstanding strength, elasticity, and compliance as well as excellent haemodynamic and anti-thrombus performance. Fabrication of a next generation vascular graft that mimics the structures and functions of natural blood vessels is becoming the pursuit of biomaterials and medical scientists.

Upregulation of BMSCs osteogenesis by positively-charged tertiary amines on polymeric implants via charge/iNOS signaling pathway.

Positively-charged surfaces on implants have a similar potential to upregulate osteogenesis of bone marrow-derived mesenchymal stem cells (BMSCs) as electromagnetic therapy approved for bone regeneration. Generally, their osteogenesis functions are generally considered to stem from the charge-induced adhesion of extracellular matrix (ECM) proteins without exploring the underlying surface charge/cell signaling molecule pathways. Herein, a positively-charged surface with controllable tertiary amines is produced on a polymer implant by plasma surface modification.

Effects of plasma-generated nitrogen functionalities on the upregulation of osteogenesis of bone marrow-derived mesenchymal stem cells.

Because of the complex plasma reactions and chemical structures of polymers, it is difficult to construct nitrogen functionalities controllably by plasma technology to attain the desirable biological outcome and hence, their effects on bone cells are sometimes ambiguous and even contradictory. In this study, argon plasma treatment is utilized to convert complex molecular chains into a pyrolytic carbon structure which possesses excellent cytocompatibility. The pyrolytic carbon then serves as a platform to prepare the desired nitrogen functionalities by nitrogen and hydrogen plasma immersion ion implantation.

Antibacterial and osteoinductive capability of orthopedic materials via cation-π interaction mediated positive charge.

Both implant centered infection and deficient osteoinduction are pivotal issues for orthopedic implants in early and long-term osseointegration, but constructing a functional bio-interface that can overcome these two problems is highly challenging. Our study reveals that a bio-interface with promoted positive charges plays an active role in simultaneously enhancing the antibacterial and osteoinductive capability of orthopedic implants. The positively charged bio-interface is fabricated by a simple dipping method, in which the cationic polymer (polyhexamethylene biguanidine, PHMB) is immobilized in the conjugated polydopamine coating.