PLA tissue-engineered scaffolds loaded with sustained-release active substance chitosan nanoparticles: Modeling BSA-bFGF as the active substance.

The utilization of basic fibroblast growth factor (bFGF) in the development of tissue-engineered scaffolds is both challenging and imperative. In our pursuit of creating a scaffold that aligns with the natural healing process, we initially fabricated chitosan-bFGF nanoparticles (CS-bFGF NPs) through electrostatic spraying. Subsequently, polylactic acid (PLA) fiber was prepared using electrospinning technique, and the CS-bFGF NPs were uniformly embedded within the pores of porous PLA fibers. Scanning electron micrographs illustrate the smooth surface of the nanoparticles, showing a porous structure intricately attached to PLA fibers. Fourier-transform infrared spectroscopy (FTIR), energy-dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD) analyses provided conclusive evidence that the CS-bFGF NPs were uniformly distributed throughout the porous PLA fibers, forming a robust physical bond through electrostatic adsorption. The resultant scaffolds exhibited commendable mechanical properties and hydrophilicity, facilitating a sustained-release for 72 h. Furthermore, the biocompatibility and degradation performance of the scaffolds were substantiated by monitoring conductivity and pH changes in pure water over different time intervals, complemented by scanning electron microscopy (SEM) observations. Cell experiments confirmed the cytocompatibility of the scaffolds. In animal studies, the group treated with 16 % NPs/Scaffold demonstrated the highest epidermal reconstruction rate. In summary, our developed materials present a promising candidate for serving as a tissue engineering scaffold, showcasing exceptional biocompatibility, sustained-release characteristics, and substantial potential for promoting epidermal regeneration.

Preparation of gastrodin modified P(VDF-TrFE)-Eudragit L100-AuNPs nanofiber membranes with piezoelectric property.

In recent years, electroactive nerve conduits made from a blend of P(VDF-TrFE) (poly (vinylidene fluoride-trifluoroethylene)) with other materials have shown significant progress. However, research combining P(VDF-TrFE) conduits with drug delivery systems remains sparse. In this study, we developed a novel gastrodin-loaded P(VDF-TrFE)-Eudragit L100-gold nanoparticles (Gas@PT-EL100-AuNPs) nanofiber membrane. Fabricated through electrospinning technique, this composite membrane aimed to investigate the impacts of gastrodin and AuNPs on its properties. Experimental results indicated that the incorporation of gold nanoparticles significantly reduced the fiber diameter of the membrane and enhanced the overall performance by improving hydrophilicity and piezoelectric properties. Specifically, the addition of AuNPs substantially enhanced the piezoelectric performance of the nanofiber membrane. Furthermore, the inclusion of gastrodin not only improved the membrane's hydrophilicity but also enabled effective release of the neuroprotective drug. These findings suggest that the Gas@PT-EL100-AuNPs nanofiber membrane is a novel biomaterial with potential applications in the repair and treatment of nerve injuries.

Advances in Large Gap Peripheral Nerve Injury Repair and Regeneration with Bridging Nerve Guidance Conduits.

Peripheral nerve injury is a common complication of accidents and diseases. The traditional autologous nerve graft approach remains the gold standard for the treatment of nerve injuries. While sources of autologous nerve grafts are very limited and difficult to obtain. Nerve guidance conduits are widely used in the treatment of peripheral nerve injuries as an alternative to nerve autografts and allografts. However, the development of nerve conduits does not meet the needs of large gap peripheral nerve injury. Functional nerve conduits can provide a good microenvironment for axon elongation and myelin regeneration. Herein, the manufacturing methods and different design types of functional bridging nerve conduits for nerve conduits combined with electrical or magnetic stimulation and loaded with Schwann cells, etc., are summarized. It summarizes the literature and finds that the technical solutions of functional nerve conduits with electrical stimulation, magnetic stimulation and nerve conduits combined with Schwann cells can be used as effective strategies for bridging large gap nerve injury and provide an effective way for the study of large gap nerve injury repair. In addition, functional nerve conduits provide a new way to construct delivery systems for drugs and growth factors in vivo.

Multifunctional electrospun membranes with hydrophilic and hydrophobic gradients property for wound dressing.

Achieving sustained and stable release of macromolecular antibacterial agents and unidirectional transport of liquids in targeted environment is still a challenge to be addressed in the management of wounds with large amounts of tissue exudates. In this work, a multilayer electrospun membrane (ethylcellulose-ethylcellulose/gelatin-quercetin/Eudragit L-100/polyethylene glycol, EC-EC/Gel-Q/EL/PEG) was designed with hydrophobic-hydrophilic gradients and drug sustained-release properties controlled by self-pumping effect and prepared using sequential electrospinning technology. The capillary force of different layers in the multilayer membrane could be controlled by precisely tuning the polymer concentrations of the inner and middle layers to extract water directly from hydrophobic inner ethylcellulose (EC) layer to hydrophilic middle ethylcellulose/gelatin (EC/Gel) layer. The droplets could not penetrate the hydrophobic side, but the drug molecules in the outer layer quercetin-loaded Eudragit L-100 (Q/EL/PEG) membrane moved after absorbing a large amount of water. The drug release behavior of multilayer wound dressing mainly followed the Korsmeyer-Peppas model. This multifunctional electrospun membrane could rapidly drive the biofluid outflow, effectively block the invasion of external contaminants and continuously release anti-inflammatory drugs, without any obvious cytotoxicity to mouse fibroblast cells. Hence, the above results indicate the excellent therapeutic potential of the proposed biomaterial as a wound dressing for diabetic patients.

Skin-inspired injectable adhesive gelatin/HA biocomposite hydrogel for hemostasis and full-thickness dermal wound healing.

An insufficient adhesion to wet surfaces and biased functions for therapeutic efficacy are limitations to the application of gelatin and hyaluronic acid. Herein, we developed a simple double-injection approach to prepare a skin-inspired gelatin/HA-based injectable remoistenable adhesive hydrogel (HI/DA-Gel) through a simultaneous crosslinking and bio-compositing strategy of genipin incorporated with dopamine (DA) grafted gelatin and N-hydroxy succinimide (NHS) merged with hyaluronic acid. The integrative crosslinking and bio-compositing strategy led to the formation of a HI/DA-Gel with a highly skin-bionic interconnected internal double network 3D-structure with elevated surface wettability, thermal-stablity, adhesive and mechanical properties as expected. In vitro/in vivo biostudies showed that HI/DA-Gel enhanced collagen deposition, hemostatic effects and upregulated the production of CD31, showing an effective hemostasis and full-thickness dermal wound healing strategy. This work proposes a novel facile double-injection approach for the design of gelatin/ hyaluronic acid multi-functional injectable bio-composite hydrogels for integrated therapeutic effects.

Preparation of Polyvinylidene Fluoride-Gold Nanoparticles Electrospinning Nanofiber Membranes.

In this work, gold nanoparticles (AuNPs) and curcumin drug were incorporated in polyvinylidene fluoride (PVDF) nanofibers by electrospinning as a novel tissue engineering scaffold in nerve regeneration. The influence of AuNPs on the morphology, crystallinity, and drug release behavior of nanofiber membranes was characterized. A successful composite nanofiber membrane sample was observed by scanning electron microscopy (SEM). The addition of AuNPs showed the improved as well as prolonged cumulative release of the drug. The results indicated that PVDF-AuNPs nanofiber membrane could potentially be applied for nerve regeneration.

Effects of the crystallinity on quercetin loaded the Eudragit L-100 electrospun nanofibers.

The quercetin loaded Eudragit L-100 nanofiber membrane with high ductility and a desired drug release rate was prepared in this work. The morphological characteristics of the Eudragit L-100 nanofibers with different drug loadings amount were observed by scanning electron microscope (SEM). After adding Polyethylene glycol-4000 (PEG-4000), the degree of the fiber breakage decreased and the fiber length increased. Fiber diameter analysis, X-ray diffraction (XRD), thermal analysis (TA) and differential scanning calorimetry (DSC) have demonstrated that the crystallinity of the fiber membrane was significantly reduced after adding PEG-4000. The mechanical property test also showed that the fiber membrane with PEG-4000 had a greater elongation at break. The in vitro release experiments showed that after adding PEG-4000, the drug-loaded fibers showed rapid release at a pH of 7.4. After adopting the strategy of reducing the crystallinity, the ductility of the fiber was enhanced, which could provide a fesibility to enable this nanofiber membrane to be used in sports wound healing treatment. The electrospun Eudragit L-100 nanofiber membranes loaded with quercetin have the potential to be applied in sport wound healing of skin, tissue and joints.

Food-Grade Pickering Emulsions: Preparation, Stabilization and Applications.

In recent years, Pickering emulsions have emerged as a new method and have attracted much attention in the fields of food sciences. Unlike conventional emulsions, Pickering emulsions are stabilized by solid particles, which can irreversibly adsorb on the oil-water interface to form a dense film to prevent the aggregation of droplets. The research and development of food-grade solid particles are increasingly favored by scientific researchers. Compared with conventional emulsions, Pickering emulsions have many advantages, such as fewer using amounts of emulsifiers, biocompatibility and higher safety, which may offer feasibility to have broad application prospects in a wide range of fields. In this article, we review the preparation methods, stabilization mechanism, degradation of Pickering emulsions. We also summarize its applications in food sciences in recent years and discuss its future prospects and challenges in this work.

Application of blocking and immobilization of electrospun fiber in the biomedical field.

The fiber obtained by electrospinning technology is a kind of biomaterial with excellent properties, which not only has a unique micro-nanostructure that gives it a large specific surface area and porosity, but also has satisfactory biocompatibility and degradability (if the spinning material used is a degradable polymer). These biomaterials provide a suitable place for cell attachment and proliferation, and can also achieve immobilization. On the other hand, its large porosity and three-dimensional spatial structure show unique blocking properties in drug delivery applications in order to achieve the purpose of slow release or even controlled release. The immobilization effect or blocking effect of these materials is mainly reflected in the hollow or core-shell structure. The purpose of this paper is to understand the application of the electrospun fiber based on biodegradable polymers (aliphatic polyesters) in the biomedical field, especially the immobilization or blocking effect of the electrospun fiber membrane on cells, drugs or enzymes. This paper focuses on the performance of these materials in tissue engineering, wound dressing, drug delivery system, and enzyme immobilization technology. Finally, based on the existing research basis of the electrospun fiber in the biomedical field, a potential research direction in the future is put forward, and few suggestions are also given for the technical problems that urgently need to be solved.