In situ MgO nanoparticle-doped Janus electrospun dressing against bacterial invasion and immune imbalance for irregular wound healing.

Owing to the unpredictable size of wounds and irregular edges formed by trauma, nanofibers' highly customizable and adherent in situ deposition can contribute to intervention in the healing process. However, electrospinning is limited by the constraints of conventional polymeric materials despite its potential for anti-inflammatory and antimicrobial properties. Here, inspired by the Janus structure and biochemistry of nanometal ions, we developed an in situ sprayed electrospinning method to overcome bacterial infections and immune imbalances during wound healing. The bilayer fiber scaffold has a hydrophobic outer layer composed of polycaprolactone (PCL) and a hydrophilic inner layer composed of gelatin, poly(L-lactic acid) (PLLA), and magnesium oxide nanoparticles, constituting the PCL/PLLA-gelatin-MgO (PPGM) electrospun scaffold. This electrospun scaffold blocked the colonization and growth of bacteria and remained stable on the wound for continuous anti-inflammatory properties to promote wound healing. Furthermore, PPGM electrospinning modulated collagen deposition and the inflammatory microenvironment in the full-thickness skin model, significantly accelerating vascularization and epithelialization progression. This personalized Janus electrospun scaffold has excellent potential as a new type of wound dressing for first aid and wound healthcare.

In-situ electrospinning PVB/Camellia oil/ZnO-TiO2 nanofibrous membranes with synergistic antibacterial and degradation of ethylene applied in fruit preservation.

This work utilizes a handheld electrospinning device to prepare a novel nanofibrous composite membrane in situ for packaging freshness. It can realize pick-and-pack and is easy to operate. The nanofibrous membrane is based on PVB as the matrix material, adding Camellia oil (CO) and ZnO-TiO2 composite nanoparticles (ZT) as the active material. The antimicrobial property of the CO and the photocatalytic activity of the nanoparticles give the material good antimicrobial and ethylene degradation functions. Meanwhile, this nanofibrous membrane has good mechanical properties, suitable moisture permeability and good optical properties. The nanofibrous membrane are suitable for both climacteric and non- climacteric fruits. Its use as a cling film extends the shelf life of strawberries by 4 days and significantly slows the ripening of small tomatoes. Therefore, this nanofibrous membrane has great potential for application in the field of fruit preservation.

In-situ electrospinning with precise deposition of antioxidant nanofiber facial mask loaded with Enteromorpha prolifera polysaccharides.

In order to fabricate a novel antioxidant nanofiber facial mask, a metal cone modified in-situ electrospinning with precise deposition was employed by utilizing Enteromorpha prolifera polysaccharides (EPPs). The metal cone could control the deposition area to achieve precise fabrication of facial mask on skin. The EPPs exhibited remarkable antioxidant ability, as evidenced by the half-maximal inhibitory concentrations (IC50) of 1.44 mg/mL and 0.74 mg/mL against DPPH and HO• free radicals, respectively. The antioxidant ability of the facial mask was improved by elevating the electrospinning voltage from 15 kV to 19 kV, due to the improved release capacity of EPPs by 7.09 %. Moreover, the facial mask demonstrated robust skin adhesion and moisture-retaining properties compared with commercial facial mask, which was benefited by the in-situ electrospinning technology. Furthermore, cytotoxicity assay, animal skin irritation test, and ocular irritation test collectively affirmed the safety of the facial mask. Thus, this research introduces a novel in situ electrospinning with precise deposition method and a natural antioxidant additive for preparing facial mask.

In-Time Detection of Plant Water Status Change by Self-Adhesive, Water-Proof, and Gas-Permeable Electrodes.

Leaf capacitance can reflect plant water content. However, the rigid electrodes used in leaf capacitance monitoring may affect plant health status. Herein, we report a self-adhesive, water-proof, and gas-permeable electrode fabricated by in situ electrospinning of a polylactic acid nanofiber membrane (PLANFM) on a leaf, spraying a layer of the carbon nanotube membrane (CNTM) on PLANFM, and in situ electrospinning of PLANFM on CNTM. The electrodes could be self-adhered to the leaf via electrostatic adhesion due to the charges on PLANFM and the leaf, thus forming a capacitance sensor. Compared with the electrode fabricated by a transferring approach, the in situ fabricated one did not show obvious influence on plant physiological parameters. On that basis, a wireless leaf capacitance sensing system was developed, and the change of plant water status was detected in the first day of drought stress, which was much earlier than direct observation of the plant appearance. This work paved a useful way to realize noninvasive and real-time detection of stress using plant wearable electronics.

Constructing the Sulfur-Doped CdO@In2O3 Nanofibers Ternary Heterojunction for Efficient Photocatalytic Hydrogen Production.

An S-doped CdO@In2O3 nanofiber was successfully designed by in-situ electrospinning along and subsequent calcination treatment. Under artificial sunlight illumination, the S/CdO@In2O3-25 displayed a superior photocatalytic hydrogen evolution rate of 4564.58 µmol·g-1·h-1, with approximately 22.0 and 1261.0-fold of those shown by the S/CdO and S/In2O3 samples, respectively. The experimental and theoretical analyses illustrate that the unique one-dimensional (1D) nanofiber morphology and rich oxygen vacancies optimized the electronic structure of the nanofibers and adsorption/desorption behaviors of reaction intermediates, contributing to the realization of the remarkable solar-to-H2 conversion efficiencies. Moreover, the staggered band structure and intimate contact heterointerfaces facilitate the formation of a type-II double charge-transfer pathway, promoting the spatial separation of photoexcited charge carriers. These results could inform the design of other advanced catalyst materials for photocatalytic reactions.

In Situ Electrospinning of Aggregation-Induced Emission Nanofibrous Dressing for Wound Healing.

Rapid wound dressing and effective antibacterial therapy that meet the extreme requirements of emergency situations are urgently needed for treating skin wounds. Here, an in situ deposited and personalized nanofibrous dressing is reported which can be directly electrospun on skin wounds by a handheld electrospinning device and perfectly fits different wounds of various sizes. Moreover, an aggregation-induced emission luminogen with photodynamic therapy effect is loaded in the nanofibrous dressings which endows the dressing's long-term antibacterial activity during the wound healing process. The in situ electrospun nanofibers show excellent antimicrobial activity against Staphylococcus aureus (S. aureus) and methicillin-resistant Staphylococcus aureus. In vivo studies demonstrate that these antibacterial nanofibrous dressings can effectively reduce inflammation and significantly accelerate wound healing. Such an in situ produced antibacterial dressing is promising as a total solution for treating emergencies, including patient-specific clinical wounds and military injuries.

In-situ electrospinning of thymol-loaded polyurethane fibrous membranes for waterproof, breathable, and antibacterial wound dressing application.

Skin-like flexible membrane with excellent water resistance and moisture permeability is an urgent need in the wound dressing field to provide comfort and protection for the wound site. Despite efforts that have been made in the development of waterproof and breathable (W&B) membranes, the in-situ electrospinning of W&B membranes suitable for irregular wound surfaces as wound dressings still faces huge challenges. In the current work, a portable electrospinning device with multi-functions, including adjustable perfusion speed for a large range from 0.05 mL/h to 10 mL/h and high voltage up to 11 kV, was designed. The thymol-loaded ethanol-soluble polyurethane (EPU) skin-like W&B nanofibrous membranes with antibacterial activity were fabricated via the custom-designed device. Ultimately, the resultant nanofibrous membranes composed of EPU, fluorinated polyurethane (FPU), and thymol presented uniform structure, robust waterproofness with the hydrostatic pressure of 17.6 cm H2O, excellent breathability of 3.56 kg m-2 d-1, the high tensile stress of 1.83 MPa and tensile strain of 453%, as well as high antibacterial activity. These results demonstrate that the new-type device has potential as a portable electrospinning apparatus for the fabrication of antibacterial membranes directly on the wound surface and puts a new way for the development of portable electrospinning devices.

Electrospinning of in situ synthesized silica-based and calcium phosphate bioceramics for applications in bone tissue engineering: A review.

The field of bone tissue engineering (BTE) focuses on the repair of bone defects that are too large to be restored by the natural healing process. To that purpose, synthetic materials mimicking the natural bone extracellular matrix (ECM) are widely studied and many combinations of compositions and architectures are possible. In particular, the electrospinning process can reproduce the fibrillar structure of bone ECM by stretching a viscoelastic solution under an electrical field. With this method, nano/micrometer-sized fibres can be produced, with an adjustable chemical composition. Therefore, by shaping bioactive ceramics such as silica, bioactive glasses and calcium phosphates through electrospinning, promising properties for their use in BTE can be obtained. This review focuses on the in situ synthesis and simultaneous electrospinning of bioceramic-based fibres while the reasons for using each material are correlated with its bioactivity. Theoretical and practical considerations for the synthesis and electrospinning of these materials are developed. Finally, investigations into the in vitro and in vivo bioactivity of different systems using such inorganic fibres are exposed.

Performance of polyvinyl pyrrolidone-isatis root antibacterial wound dressings produced in situ by handheld electrospinner.

Antibacterial dressings are an increasingly important tool for the prevention and management of wound infections, particularly in light of concerns surrounding conventional drug-resistant antibiotics. Handheld electrospinning devices provide opportunities for the rapid application of antibacterial dressing materials to wounds, but spinning formulations need to be compatible with live biological surfaces. We report the development of a new antibacterial formulation compatible with handheld electrospinning, and its manufacture directly on a wound site. Nanofibrous dressing mats were produced from polyvinyl pyrrolidone (PVP) containing isatis root (Indigowoad root or Ban-Lan-Gen), a traditional Chinese medicine, commonly used for the treatment of infectious disease. The resulting wound dressing mats of PVP/isatis root exhibited well-defined fibrous structures and excellent surface wetting, and permeability characteristics. The presence of isatis root conferred antibacterial activity against gram negative and gram positive strains. Moreover, in a Kunming mouse skin injury model, direct electrospinning of PVP/isatis root formulations on to wound sites produced near complete wound closure after 11 days and epidermal repair in histological studies.

In Situ Electrospun Zein/Thyme Essential Oil-Based Membranes as an Effective Antibacterial Wound Dressing.

Wound dressings are an important element in promoting the healing of wounds. Electrospun fibrous materials have a highly porous structure and controllable antibacterial activity and are therefore popular as potential wound dressings. However, electrospun fibrous wound dressings are usually conveniently packaged for immediate use but cannot accommodate irregularly shaped wounds, and their misuse runs the risk of causing a secondary injury to the wound. To overcome these issues, in situ electrospun zein/thyme essential oil (TEO) nanofibrous membranes are proposed as a potential type of wound dressing and applied for wound management through an in situ electrospinning process, which uses a portable electrospinning device. The as-spun zein/TEO membranes show high gas permeability up to 154 ± 20.9 m2/s and superhydrophilicity with a 0° contact angle. With the addition of TEO, good antibacterial effects are also imparted onto the membrane to prevent infection. Moreover, the in situ electrospinning can directly deposit the zein/TEO membranes onto the site of the wound to accommodate the shape of the wound with increased convenience and perceived comfort. Experiments carried out on mice suggest that the in situ electrospun zein/TEO membrane greatly promotes the wound healing process within 11 days. The study results, therefore, suggest that wound dressings in the form of in situ electrospun zein/TEO membranes can be used to facilitate wound healing.

In Situ Electrospinning Iodine-Based Fibrous Meshes for Antibacterial Wound Dressing.

For effective application of electrospinning and electrospun fibrous meshes in wound dressing, we have in situ electrospun poly(vinyl pyrrolidone)/iodine (PVP/I), PVP/poly(vinyl pyrrolidone)-iodine (PVPI) complex, and poly(vinyl butyral) (PVB)/PVPI solutions into fibrous membranes by a handheld electrospinning apparatus. The morphologies of the electrospun fibers were examined by SEM, and the hydrophobicity, gas permeability, and antibacterial properties of the as-spun meshes were also investigated. The flexibility and feasibility of in situ electrospinning PVP/I, PVP/PVPI, and PVB/PVPI membranes, as well as the excellent gas permeabilities and antibacterial properties of the as-spun meshes, promised their potential applications in wound healing.