A Review on Electrospun Poly(amino acid) Nanofibers and Their Applications of Hemostasis and Wound Healing

Advances in Adhesive Materials for Oral and Maxillofacial Soft Tissue Diseases

Oral diseases represent a prevalent global health burden, profoundly affecting patients' quality of life. Given the involvement of oral mucosa and muscles in diverse physiological functions, coupled with clinical aesthetics considerations, repairing oral and maxillofacial soft tissue defects poses a formidable challenge. Wet-adhesive materials are regarded as promising oral repair materials due to their unique advantages in easily overcoming physical and biological barriers in the oral cavity. This review first introduces the intricate wet-state environment prevalent in the oral cavity, meticulously explaining the fundamental physical and chemical adhesion mechanisms that underpin adhesive materials. It then comprehensively summarizes the diverse types of adhesives utilized in stomatology, encompassing polysaccharide, protein, and synthetic polymer adhesive materials. The review further evaluates the latest research advancements in utilizing these materials to treat various oral and maxillofacial soft tissue diseases, including oral mucosal diseases, periodontitis, peri-implantitis, oral and maxillofacial skin defects, and maxillofacial tumors. Finally, it also highlights the promising future prospects and pivotal challenges related to stomatology application of multifunctional adhesive materials.

Challenges and opportunities of poly(amino acid) nanomedicines in cancer therapy

Poly(amino acid) nanomedicines hold significant promise for cancer therapy. However, their clinical translation has not matched the extensive efforts of scientists or the burgeoning body of research. The therapeutic outcomes with most nanomedicines often fall short of the promising results observed in animal experiments. This review explores the challenges faced in cancer therapy using poly(amino acid) nanomedicines, particularly addressing the controversies surrounding the enhanced permeability and retention effect and the lack of methods for controlled and reproducible mass production of poly(amino acid) nanomedicines. Furthermore, this review examines the opportunities emerging in this field due to the rapid advancements in artificial intelligence.

Bovine serum albumin and lysozyme nanofibers as versatile platforms for preserving loaded bioactive compounds

In this study, the electrospinning procedure was optimized to create polyethylene oxide (PEO) NFs highly enriched in proteins with non-structural functions while preserving their activity. For this purpose, several immune-related proteins of low, medium and high molecular weights were used as molecular models. Initially, the electrospinning parameters were adjusted using 3 % w/w PEO and bovine serum albumin (BSA, 5-20 % w/w). As determined by FESEM, their average diameters ranged from 301 to 752 nm, and those with higher protein content (15-20 %) yielded more uniform NFs in both size and morphology terms. Protein integrity remained stable as determined by SDS-PAGE and FTIR. Similar results were observed for the polypeptide lysozyme (LYZ) when incorporated in NFs under these settings. To further explore the potential of these materials, the antimicrobial peptide piscidin (PIS) and an antibody (Ab, HRP-IgG) were used to produce BSA/PIS, LYZ/PIS and BSA/Ab NFs and evaluate the preservation of their activity. The antibacterial assays showed that, in most bacterial species, the activity of PIS remained consistent after being incorporated into the NFs. Furthermore, the activity of HRP-IgG was maintained within the NFs, with enhanced preservation observed in BSA/Ab NFs. These findings expand the possibilities of protein utilization across various applications through nanomaterials.

Advances of antimicrobial dressings loaded with antimicrobial agents in infected wounds

Wound healing is a complex process that is critical for maintaining the barrier function of the skin. However, when a large quantity of microorganisms invade damaged skin for an extended period, they can cause local and systemic inflammatory responses. If left untreated, this condition may lead to chronic infected wounds. Infected wounds significantly escalate wound management costs worldwide and impose a substantial burden on patients and healthcare systems. Recent clinical trial results suggest that the utilization of effective antimicrobial wound dressing could represent the simplest and most cost-effective strategy for treating infected wounds, but there has hitherto been no comprehensive evaluation reported on the efficacy of antimicrobial wound dressings in promoting wound healing. Therefore, this review aims to systematically summarize the various types of antimicrobial wound dressings and the current research on antimicrobial agents, thereby providing new insights for the innovative treatment of infected wounds.

Nanofiber Graft Therapy to Prevent Shoulder Stiffness and Adhesions after Rotator Cuff Tendon Repair: A Comprehensive Review

Stiffness and adhesions following rotator cuff tears (RCTs) are common complications that negatively affect surgical outcomes and impede healing, thereby increasing the risk of morbidity and failure of surgical interventions. Tissue engineering, particularly through the use of nanofiber scaffolds, has emerged as a promising regenerative medicine strategy to address these complications. This review critically assesses the efficacy and limitations of nanofiber-based methods in promoting rotator cuff (RC) regeneration and managing postrepair stiffness and adhesions. It also discusses the need for a multidisciplinary approach to advance this field and highlights important considerations for future clinical trials.

Plasma Surface Treatment and Application of Polyvinyl Alcohol/Polylactic Acid Electrospun Fibrous Hemostatic Membrane

In this study, an improved PVA/PLA fibrous hemostatic membrane was prepared by electrospinning technology combined with air plasma modification. The plasma treatment was used to modify PLA to enhance the interlayer bonding between the PVA and PLA fibrous membranes first, then modify the PVA to improve the hemostatic capacity. The surfaces of the PLA and PVA were oxidized after air plasma treatment, the fibrous diameter was reduced, and roughness was increased. Plasma treatment enhanced the interfacial bond strength of PLA/PVA composite fibrous membrane, and PLA acted as a good mechanical support. Plasma-treated PVA/PLA composite membranes showed an increasing liquid-enrichment capacity of 350% and shortened the coagulation time to 258 s. The hemostatic model of the liver showed that the hemostatic ability of plasma-treated PVA/PLA composite membranes was enhanced by 79% compared to untreated PVA membranes, with a slight improvement over commercially available collagen. The results showed that the plasma-treated PVA/PLA fibers were able to achieve more effective hemostasis, which provides a new strategy for improving the hemostatic performance of hemostatic materials.

Advances of biological macromolecules hemostatic materials: A review

Achieving hemostasis is a necessary intervention to rapidly and effectively control bleeding. Conventional hemostatic materials currently used in clinical practice may aggravate the damage at the bleeding site due to factors such as poor adhesion and poor adaptation. Compared to most traditional hemostatic materials, polymer-based hemostatic materials have better biocompatibility and offer several advantages. They provide a more effective method of stopping bleeding and avoiding additional damage to the body in case of excessive blood loss. Various hemostatic materials with greater functionality have been developed in recent years for different organs using diverse design strategies. This article reviews the latest advances in the development of polymeric hemostatic materials. We introduce the coagulation cascade reaction after bleeding and then discuss the hemostatic mechanisms and advantages and disadvantages of various polymer materials, including natural, synthetic, and composite polymer hemostatic materials. We further focus on the design strategies, properties, and characterization of hemostatic materials, along with their applications in different organs. Finally, challenges and prospects for the application of hemostatic polymeric materials are summarized and discussed. We believe that this review can provide a reference for related research on hemostatic materials, contributing to the further development of polymer hemostatic materials.

Nanofibrous composite from chitosan-casein polyelectrolyte complex for rapid hemostasis in rat models in vivo

Bleeding causes ∼5.8 million deaths globally; half of the patients die if rapid hemostasis is not achieved. Here, we report a chitosan-casein (CC)-based nanofibrous polyelectrolyte complex (PEC) that could clot blood within 10 s in the rat femoral artery model in vivo. The nanofiber formation by self-assembly was also optimized for process parameters (concentration, mixing ratio, pH, and ultrasonication). Results showed that increasing the concentration of chitosan from 10 % to 90 % in the formulation increased the productivity (r = 0.99) of PECs but led to increased blood clotting time (r = 0.90) due to an increase in zeta potential (r = 0.98), fiber diameter (r = 0.93), and decreased surface porosity (r = -0.99), absorption capacity (r = -0.99). The pH also influenced the zeta potential of PEC, with an optimized pH of 8.0 ± 0.1 yielding clear nanofibers. Sonication improved the segregation of nanofibers by promoting water removal. The optimized PECs containing chitosan and casein in the ratio of 30:70 (CC30) at a pH of 8.0 and dehydration under sonication could clot the blood within 9 ± 2 s in vitro and 9 ± 2 s in rat femoral artery puncture model. The CC30 formulation did not cause any irritation or corrosion on rat skin. Histopathology and immunohistochemistry of various organs showed that CC30 was biocompatible and non-immunogenic under in vivo conditions.

Topical application of hyaluronic acid and amino acids in hard-to-heal wounds: a cost-effectiveness analysis

OBJECTIVE

The aim of this cost-effectiveness analysis was to estimate the monetary cost required to achieve a gain in health benefit. An analytic model to evaluate the cost-effectiveness of a topical medical device comprising a mixture of hyaluronic acid and amino acids (HA+AA medical device) (Vulnamin, Professional Dietetics SpA, Italy) as compared to standard of care (SoC) for hard-to-heal (chronic) wounds is presented.

METHOD

Retrospective data was analysed from a cohort of patients as well as information from published literature. For each paper, the following information was extracted: number of patients enrolled in each treatment arm and the results of prespecified reviewed outcomes.

RESULTS

A total of six studies involving 378 patients were included in this pooled analysis. Findings showed that treatment with the HA+AA medical device has the potential to lower consumption of resources. With regards to wound healing, in both superficial and deep wounds, treatment benefits of the HA+AA medical device included: rapid wound size reduction; faster healing; reduction of dressing changes; reduced infection risk; and reduced treatment costs. Results showed the HA+AA medical device to be 32% more cost-effective than comparators in the treatment of hard-to-heal wounds (time horizon selected=six months).

CONCLUSION

The findings of this analysis showed that treatment with the HA+AA medical device is a valid alternative to SoC care because it is cheaper, and its utility and effectiveness are greater. In addition, the results of the analysis showed a direct relationship between the time to complete healing and the increase in costs (increasing the period of time to reach complete healing increases the costs associated with the treatment).

Poly(Glutamic Acid)-Engineered Nanoplatforms for Enhanced Cancer Phototherapy

Phototherapies, including photothermal therapy and photodynamic therapy, have gained booming development over the past several decades for their attractive non-invasiveness nature, negligible adverse effects, minimal systemic toxicity, and high spatial selectivity. Phototherapy usually requires three components: light irradiation, photosensitizers, and molecular oxygen. Photosensitizers can convert light energy into heat or reactive oxygen species, which can be used in the tumor-killing process. The direct application of photosensitizers in tumor therapy is restricted by their poor water solubility, fast clearance, severe toxicity, and low cellular uptake. The encapsulation of photosensitizers into nanostructures is an attractive strategy to overcome these critical limitations. Poly(glutamic acid) (PGA) is a kind of poly(amino acid)s containing the repeating units of glutamic acid. PGA has superiority for cancer treatment because of its good biocompatibility, low immunogenicity, and modulated pH responsiveness. The hydrophilicity nature of PGA allows the physical entrapment of photosensitizers and anticancer drugs via the construction of amphiphilic polymers. Moreover, the pendent carboxyl groups of PGA enable chemical conjugation with therapeutic agents. In this mini-review, we highlight the stateof- the-art design and fabrication of PGA-based nanoplatforms for phototherapy. We also discuss the potential challenges and future perspectives of phototherapy, and clinical translation of PGA-based nanomedicines.

Bletilla striata composite nanofibrous membranes prepared by emulsion electrospinning for enhanced healing of diabetic wounds

Diabetic wounds impose enormous distress and financial burden on patients, and finding effective dressings to manage wounds is critical. As a Chinese herbal medicine with a long history of Clinical application, Bletilla striata has significant medicinal effects in the therapy of various wounds. In this study, PLA and the pharmacodynamic substances of Bletilla striata were prepared into fibrous scaffolds by emulsion electrospinning technology for the management of diabetic wounds in mice. The results of scanning electron microscopy showed that the core-shell structure fibre was successfully obtained by emulsion electrospinning. The fibre membrane exhibited excellent water absorption capability and water vapor transmission rate, could inhibit the growth of Staphylococcus aureus and Pseudomonas aeruginosa, had good compatibility, and achieved excellent healing effect on diabetic wounds. Especially in the in vivo wound healing experiment, the wound healing rate of composite fibre membrane treatment reached 98.587 ± 2.149% in 16 days. This work demonstrated the good therapeutic effect of the developed fibrous membrane to diabetic wound, and this membrane could be potentially applied to chronic wound healing.

Polydopamine-Coated Polycaprolactone Electrospun Nanofiber Membrane Loaded with Thrombin for Wound Hemostasis

Hemorrhagic shock is the primary cause of death in patients with severe trauma, and the development of rapid and efficient hemostatic methods is of great significance in saving the lives of trauma patients. In this study, a polycaprolactone (PCL) nanofiber membrane was prepared by electrospinning. A PCL-PDA loading system was developed by modifying the surface of polydopamine (PDA), using inspiration from mussel adhesion protein, and the efficient and stable loading of thrombin (TB) was realized to ensure the bioactivity of TB. The new thrombin loading system overcomes the disadvantages of harsh storage conditions, poor strength, and ease of falling off, and it can use thrombin to start a rapid coagulation cascade reaction, which has the characteristics of fast hemostasis, good biocompatibility, high safety, and a wide range of hemostasis. The physicochemical properties and biocompatibility of the PCL-PDA-TB membrane were verified by scanning electron microscopy, the cell proliferation test, the cell adhesion test, and the extract cytotoxicity test. Red blood cell adhesion, platelet adhesion, dynamic coagulation time, and animal models all verified the coagulation effect of the PCL-PDA-TB membrane. Therefore, the PCL-PDA-TB membrane has great potential in wound hemostasis applications, and should be widely used in various traumatic hemostatic scenarios.

Nanoparticle delivery of TFOs is a novel targeted therapy for HER2 amplified breast cancer

PURPOSE

The human EGFR2 (HER2) signaling pathway is one of the most actively studied targets in cancer transformation research. Ttriplex-forming oligonucleotides (TFOs) activate DNA damage and induce apoptosis. We aim to encapsulate TFO-HER2 with nano-particle ZW-128 to suppress breast cell growth in vitro and in vivo.

EXPERIMENTAL DESIGN

We designed a set of TFO fragments targeting HER2 and verified their effectiveness. We encapsulated TFO-HER2 in ZW-128 to form nano-drug TFO@ZW-128. Cell counting kit 8, flow cytometry, and western blotting were used to evaluate the effect of TFO@ZW-128 on cell proliferation and the expressions of related proteins. The ant-itumor effect of TFO@ZW-128 was evaluated in vivo using nude mice breast cancer model.

RESULTS

TFO@ZW-128 had efficient cellular uptake in amplified HER2 breast cancer cells. TFO@ZW-128 showed an 80-fold increase in TFO utilization compared with TFO-HER2 in the nude mouse breast cancer model. Meanwhile, TFO@ZW-128 dramatically inhibited the growth of HER2-overexpressing tumors compared with TFO-HER2 (P < 0.05). Furthermore, TFO@ZW-128-induced cell apoptosis was in a p53-independent manner.

CONCLUSIONS

In this study, we designed nano-drug TFO@ZW-128, which has proven effective and non-toxic in targeted therapy for ectopic HER2-expressing tumors.

Electrospun Biomolecule-Based Drug Delivery Systems

Drug delivery, mainly a professional term in pharmaceutics, is a field of interdisciplinary intersection and integration [...].

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.

Nanofibrous Scaffolds for Diabetic Wound Healing

Chronic wounds are one of the secondary health complications that develop in individuals who have poorly managed diabetes mellitus. This is often associated with delays in the wound healing process, resulting from long-term uncontrolled blood glucose levels. As such, an appropriate therapeutic approach would be maintaining blood glucose concentration within normal ranges, but this can be quite challenging to achieve. Consequently, diabetic ulcers usually require special medical care to prevent complications such as sepsis, amputation, and deformities, which often develop in these patients. Although several conventional wound dressings, such as hydrogels, gauze, films, and foams, are employed in the treatment of such chronic wounds, nanofibrous scaffolds have gained the attention of researchers because of their flexibility, ability to load a variety of bioactive compounds as single entities or combinations, and large surface area to volume ratio, which provides a biomimetic environment for cell proliferation relative to conventional dressings. Here, we present the current trends on the versatility of nanofibrous scaffolds as novel platforms for the incorporation of bioactive agents suitable for the enhancement of diabetic wound healing.

Electrospun Mucoadhesive Zein/PVP Fibroporous Membrane for Transepithelial Delivery of Propranolol Hydrochloride

Mucoadhesive drug delivery systems have been extensively studied to effectively reduce the limitations of conventional drug delivery systems. Zein and polyvinyl pyrrolidone (PVP) are appraised for mucoadhesive properties. This study focuses on developing a mechanically stable zein/PVP electrospun membrane for propranolol hydrochloride (PL) transport. Fourier transform infrared, Raman spectra, and swelling studies gave evidence for PVP crosslinking, whereas circular dichroism spectroscopy revealed crosslinking of zein owing to the conformational change from α-helix to β-sheet. A 10 h thermal treatment of zein/PVP imparted 3.92 ± 0.13 MPa tensile strength to the matrix. Thermally crosslinked electrospun zein/PVP matrix showed 22.1 ± 0.1 g mm work of adhesion in porcine buccal mucosa tissue. Qualitative and quantitative evaluation of cytotoxicity in RPMI 2650 has been carried out. The in vitro drug release profile of PL from thermally crosslinked zein/PVP best fitted with the Korsmeyer-Peppas model. Immunostaining of β-catenin adherens junctional protein confirmed the absence of paracellular transport through the junctional opening. Still, drug permeation was observed through the porcine buccal mucosa, attributed to the transcellular transport of PL owing to its lipophilicity. The ex vivo permeation of PL through porcine buccal mucosa was also evaluated.

Development of Verapamil Hydrochloride-loaded Biopolymer-based Composite Electrospun Nanofibrous Mats: In vivo Evaluation of Enhanced Burn Wound Healing without Scar Formation

Introduction

Researchers aim for new heights in wound healing to produce wound dressings with unique features. Natural, synthetic, biodegradable, and biocompatible polymers especially in the nanoscale are being employed to support and provide efficient wound management. Economical and environmentally friendly sustainable wound management alternatives are becoming an urgent issue to meet future needs. Nanofibrous mats possess unique properties for ideal wound healing. They mimic the physical structure of the natural extracellular matrix (ECM), promote hemostasis, and gas permeation. Their interconnected nanoporosity prevents wound dehydration and microbial infiltration.

Purpose

To prepare and evaluate a novel verapamil HCl-loaded environmentally friendly composite, with biopolymer-based electrospun nanofibers suitable for application as wound dressings providing adequate wound healing with no scar formation.

Methods

Composite nanofibers were prepared by electrospinning of a blend of the natural biocompatible polymers, sodium alginate (SA) or zein (Z) together with polyvinyl alcohol (PVA). Composite nanofibers were characterized in terms of morphology, diameter, drug entrapment efficiency, and release. In vivo study of the therapeutic efficacy of verapamil HCl-loaded nanofibers on a Sprague Dawley rat model with dermal burn wound was investigated in terms of percent wound closure, and presence of scars.

Results

Combining PVA with SA or Z improved the electrospinnability and properties of the developed nanofibers. Verapamil HCl-loaded composite nanofibers showed good pharmaceutical attributes favorable for wound healing including, fiber diameter ∼150 nm, high entrapment efficiency (∼80-100%) and biphasic controlled drug release for 24 h. In vivo study demonstrated promising potentials for wound healing without scaring.

Conclusion

The developed nanofibrous mats combined the beneficial properties of the biopolymers and verapamil HCl to provide an increased functionality by exploiting the unique advantages of nanofibers in wound healing at a small dose proved to be insufficient in case of the conventional dosage form.

Delivery of streptomycin to the rat colon by use of electrospun nanofibers

Drug-loaded electrospun nanofibers are potential drug carrier systems that may optimize disease treatment while reducing the impact on commensal microbes. The feasibility of streptomycin-loaded pullulan nanofibers fabricated from a green electrospinning procedure using water as the solvent was assessed. We conducted a rat study including a group treated with streptomycin-loaded nanofibers (STR-F, n = 5), a group treated with similar concentrations of streptomycin in the drinking water (STR-W, n = 5), and a non-treated control group (CTR, n = 5). Streptomycin was successfully loaded into nanofibers and delivered by this vehicle, which minimized the quantity of the drug released in the ileal compartment of the gut. Ingested streptomycin-resistant E. coli colonized of up to 10⁶ CFU/g feces, revealing a selective effect of streptomycin even when given in the low amounts allowed by the nanofiber-based delivery. 16S amplicon sequencing of the indigenous microbiota revealed differential effects in the three groups. An increase of Peptostreptococcaceae in the cecum of STR-F animals may indicate that the fermentation of nanofibers directly or indirectly promoted growth of bacteria within this family. Our results elucidate relevant properties of electrospun nanofibers as a novel vehicle for delivery of antimicrobials to the large intestine.

Effect of composite biodegradable biomaterials on wound healing in diabetes

The repair of diabetic wounds has always been a job that doctors could not tackle quickly in plastic surgery. To solve this problem, it has become an important direction to use biocompatible biodegradable biomaterials as scaffolds or dressing loaded with a variety of active substances or cells, to construct a wound repair system integrating materials, cells, and growth factors. In terms of wound healing, composite biodegradable biomaterials show strong biocompatibility and the ability to promote wound healing. This review describes the multifaceted integration of biomaterials with drugs, stem cells, and active agents. In wounds, stem cells and their secreted exosomes regulate immune responses and inflammation. They promote angiogenesis, accelerate skin cell proliferation and re-epithelialization, and regulate collagen remodeling that inhibits scar hyperplasia. In the process of continuous combination with new materials, a series of materials that can be well matched with active ingredients such as cells or drugs are derived for precise delivery and controlled release of drugs. The ultimate goal of material development is clinical transformation. At present, the types of materials for clinical application are still relatively single, and the bottleneck is that the functions of emerging materials have not yet reached a stable and effective degree. The development of biomaterials that can be further translated into clinical practice will become the focus of research.

Advances in the Preparation of Nanofiber Dressings by Electrospinning for Promoting Diabetic Wound Healing

Chronic diabetic wounds are one of the main complications of diabetes, manifested by persistent inflammation, decreased epithelialization motility, and impaired wound healing. This will not only lead to the repeated hospitalization of patients, but also bear expensive hospitalization costs. In severe cases, it can lead to amputation, sepsis or death. Electrospun nanofibers membranes have the characteristics of high porosity, high specific surface area, and easy functionalization of structure, so they can be used as a safe and effective platform in the treatment of diabetic wounds and have great application potential. This article briefly reviewed the pathogenesis of chronic diabetic wounds and the types of dressings commonly used, and then reviewed the development of electrospinning technology in recent years and the advantages of electrospun nanofibers in the treatment of diabetic wounds. Finally, the reports of different types of nanofiber dressings on diabetic wounds are summarized, and the method of using multi-drug combination therapy in diabetic wounds is emphasized, which provides new ideas for the effective treatment of diabetic wounds.

The Applications of Ferulic-Acid-Loaded Fibrous Films for Fruit Preservation

The aim of this study was to develop a novel ultrathin fibrous membrane with a core-sheath structure as an antioxidant food packaging membrane. The core-sheath structure was prepared by coaxial electrospinning, and the release of active substances was regulated by its special structure. Ferulic acid (FA) was incorporated into the electrospun zein/polyethylene oxide ultrathin fibers to ensure their synergistic antioxidant properties. We found that the prepared ultrathin fibers had a good morphology and smooth surface. The internal structure of the fibers was stable, and the three materials that we used were compatible. For the different loading positions, it was observed that the core layer ferulic-acid-loaded fibers had a sustained action, while the sheath layer ferulic-acid-loaded fibers had a pre-burst action. Finally, apples were selected for packaging using fibrous membranes to simulate practical applications. The fibrous membrane was effective in reducing water loss and apple quality loss, as well as extending the shelf life. According to these experiments, the FA-loaded zein/PEO coaxial electrospinning fiber can be used as antioxidant food packaging and will also undergo more improvements in the future.

Rapid Sublingual Delivery of Piroxicam from Electrospun Cyclodextrin Inclusion Complex Nanofibers

Piroxicam (Px) is a nonsteroidal anti-inflammatory drug (NSAID) used for the treatment of osteoarthritis and rheumatoid arthritis. It is administered orally; however, its poor water solubility causes low loading to the nonconventional drug delivery systems (DDSs), such as electrospun fibers. Furthermore, the rapid dissolution of DDS and fast release of the embedded drugs are crucial for oral delivery of drugs to patients who are unconscious or suffering from dysphagia. In this regard, this study reports the development of rapidly dissolving cyclodextrin (CD)-based inclusion complex (IC) nanofibers by waterborne electrospinning for fast oral delivery of Px. Scanning electron microscopy analysis revealed the formation of bead-free fibers with a mean diameter range of 170-500 nm at various concentrations of Px; increasing the Px loading decreased the fiber diameter. The formation of IC was demonstrated by X-ray diffraction (XRD) analysis by the disappearance of crystalline peaks of Px. Likewise, differential scanning calorimetry (DSC) analysis showed the disappearance of the melting peak of the embedded Px due to IC formation. Both Fourier transform infrared (FTIR) and thermogravimetric analysis (TGA) confirmed the presence of Px within the fibers. ¹H NMR experiments demonstrated Px preservation in the fibers after six months. Px-loaded nanofibers were employed for sublingual drug delivery. To mimic the environment of the mouth, the nanofibers were treated with artificial saliva, which revealed the instant dissolution of the nanofibers. Furthermore, dissolution experiments were performed on the tissues wetted with artificial saliva, where the dissolution of the fibers could be extended to a few seconds, demonstrating the suitability of the materials for sublingual oral drug delivery. Overall, this paper, for the first time, reports the rapid oral delivery of Px from polymer-free CD fibers produced by waterborne electrospinning without the requirement of any carrier polymer and toxic solvent.

Electrospun Porous Nanofibers: Pore−Forming Mechanisms and Applications for Photocatalytic Degradation of Organic Pollutants in Wastewater

Electrospun porous nanofibers have large specific surface areas and abundant active centers, which can effectively improve the properties of nanofibers. In the field of photocatalysis, electrospun porous nanofibers can increase the contact area of loaded photocatalytic particles with light, shorten the electron transfer path, and improve photocatalytic activity. In this paper, the main pore−forming mechanisms of electrospun porous nanofiber are summarized as breath figures, phase separation (vapor−induced phase separation, non−solvent−induced phase separation, and thermally induced phase separation) and post−processing (selective removal). Then, the application of electrospun porous nanofiber loading photocatalytic particles in the degradation of pollutants (such as organic, inorganic, and bacteria) in water is introduced, and its future development prospected. Although porous structures are beneficial in improving the photocatalytic performance of nanofibers, they reduce their mechanical properties. Therefore, strategies for improving the mechanical properties of electrospun porous nanofibers are also briefly discussed.

Electrospun Nanofibers for Periodontal Treatment: A Recent Progress

Periodontitis is a major threat to oral health, prompting scientists to continuously study new treatment techniques. The nanofibrous membrane prepared via electrospinning has a large specific surface area and high porosity. On the one hand, electrospun nanofibers can improve the absorption capacity of proteins and promote the expression of specific genes. On the other hand, they can improve cell adhesion properties and prevent fibroblasts from passing through the barrier membrane. Therefore, electrospinning has unique advantages in periodontal treatment. At present, many oral nanofibrous membranes with antibacterial, anti-inflammatory, and tissue regeneration properties have been prepared for periodontal treatment. First, this paper introduces the electrospinning process. Then, the commonly used polymers of electrospun nanofibrous membranes for treating periodontitis are summarized. Finally, different types of nanofibrous membranes prepared via electrospinning for periodontal treatment are presented, and the future evolution of electrospinning to treat periodontitis is described.

Advances in the Application of Electrospun Drug-Loaded Nanofibers in the Treatment of Oral Ulcers

Oral ulcers affect oral and systemic health and have high prevalence in the population. There are significant individual differences in the etiology and extent of the disease among patients. In the treatment of oral ulcers, nanofiber films can control the drug-release rate and enable long-term local administration. Compared to other drug-delivery methods, nanofiber films avoid the disadvantages of frequent administration and certain side effects. Electrospinning is a simple and effective method for preparing nanofiber films. Currently, electrospinning technology has made significant breakthroughs in energy-saving and large-scale production. This paper summarizes the polymers that enable oral mucosal adhesion and the active pharmaceutical ingredients used for oral ulcers. Moreover, the therapeutic effects of currently available electrospun nanofiber films on oral ulcers in animal experiments and clinical trials are investigated. In addition, solvent casting and cross-linking methods can be used in conjunction with electrospinning techniques. Based on the literature, more administration systems with different polymers and loading components can be inspired. These administration systems are expected to have synergistic effects and achieve better therapeutic effects. This not only provides new possibilities for drug-loaded nanofibers but also brings new hope for the treatment of oral ulcers.

Electrospun Zein/Polyoxyethylene Core-Sheath Ultrathin Fibers and Their Antibacterial Food Packaging Applications

The purpose of this work is to develop a novel ultrathin fibrous membrane with a core-sheath structure as antibacterial food packaging film. Coaxial electrospinning was exploited to create the core-sheath structure, by which the delivery regulation of the active substance was achieved. Resveratrol (RE) and silver nanoparticles (AgNPs) were loaded into electrospun zein/polyethylene oxide ultrathin fibers to ensure a synergistic antibacterial performance. Under the assessments of a scanning electron microscope and transmission electron microscope, the ultrathin fiber was demonstrated to have a fine linear morphology, smooth surface and obvious core-sheath structure. X-ray diffraction and Fourier transform infrared analyses showed that RE and AgNPs coexisted in the ultrathin fibers and had good compatibility with the polymeric matrices. The water contact angle experiments were conducted to evaluate the hydrophilicity and hygroscopicity of the fibers. In vitro dissolution tests revealed that RE was released in a sustained manner. In the antibacterial experiments against Staphylococcus aureus and Escherichia coli, the diameters of the inhibition zone of the fiber were 8.89 ± 0.09 mm and 7.26 ± 0.10 mm, respectively. Finally, cherry tomatoes were selected as the packaging object and packed with fiber films. In a practical application, the fiber films effectively reduced the bacteria and decreased the quality loss of cherry tomatoes, thereby prolonging the fresh-keeping period of cherry tomatoes to 12 days. Following the protocols reported here, many new food packaging films can be similarly developed in the future.

Study on Filtration Performance of PVDF/PUL Composite Air Filtration Membrane Based on Far-Field Electrospinning

At present, the situation of air pollution is still serious, and research on air filtration is still crucial. For the nanofiber air filtration membrane, the diameter, porosity, tensile strength, and hydrophilicity of the nanofiber will affect the filtration performance and stability. In this paper, based on the far-field electrospinning process and the performance effect mechanism of the stacked structure fiber membrane, nanofiber membrane was prepared by selecting the environmental protection, degradable and pollution-free natural polysaccharide biopolymer pullulan, and polyvinylidene fluoride polymer with strong hydrophobicity and high impact strength. By combining two kinds of fiber membranes with different fiber diameter and porosity, a three-layer composite nanofiber membrane with better hydrophobicity, higher tensile strength, smaller fiber diameter, and better filtration performance was prepared. Performance characterization showed that this three-layer composite nanofiber membrane had excellent air permeability and filtration efficiency, and the filtration efficiency of particles above PM 2.5 reached 99.9%. This study also provides important reference values for the preparation of high-efficiency composite nanofiber filtration membrane.

Electrospun nanofiber-based glucose sensors for glucose detection

Diabetes is a chronic, systemic metabolic disease that leads to multiple complications, even death. Meanwhile, the number of people with diabetes worldwide is increasing year by year. Sensors play an important role in the development of biomedical devices. The development of efficient, stable, and inexpensive glucose sensors for the continuous monitoring of blood glucose levels has received widespread attention because they can provide reliable data for diabetes prevention and diagnosis. Electrospun nanofibers are new kinds of functional nanocomposites that show incredible capabilities for high-level biosensing. This article reviews glucose sensors based on electrospun nanofibers. The principles of the glucose sensor, the types of glucose measurement, and the glucose detection methods are briefly discussed. The principle of electrospinning and its applications and advantages in glucose sensors are then introduced. This article provides a comprehensive summary of the applications and advantages of polymers and nanomaterials in electrospun nanofiber-based glucose sensors. The relevant applications and comparisons of enzymatic and non-enzymatic nanofiber-based glucose sensors are discussed in detail. The main advantages and disadvantages of glucose sensors based on electrospun nanofibers are evaluated, and some solutions are proposed. Finally, potential commercial development and improved methods for glucose sensors based on electrospinning nanofibers are discussed.

Recent Progress in Electrospun Polyacrylonitrile Nanofiber-Based Wound Dressing

Bleeding control plays a very important role in worldwide healthcare, which also promotes research and development of wound dressings. The wound healing process involves four stages of hemostasis, inflammation, proliferation and remodeling, which is a complex process, and wound dressings play a huge role in it. Electrospinning technology is simple to operate. Electrospun nanofibers have a high specific surface area, high porosity, high oxygen permeability, and excellent mechanical properties, which show great utilization value in the manufacture of wound dressings. As one of the most popular reactive and functional synthetic polymers, polyacrylonitrile (PAN) is frequently explored to create nanofibers for a wide variety of applications. In recent years, researchers have invested in the application of PAN nanofibers in wound dressings. Research on spun nanofibers is reviewed, and future development directions and prospects of electrospun PAN nanofibers for wound dressings are proposed.

Electrospun Core–Sheath Nanofibers with Variable Shell Thickness for Modifying Curcumin Release to Achieve a Better Antibacterial Performance

The inefficient use of water-insoluble drugs is a major challenge in drug delivery systems. Core–sheath fibers with various shell thicknesses based on cellulose acetate (CA) were prepared by the modified triaxial electrospinning for the controlled and sustained release of the water-insoluble Chinese herbal active ingredient curcumin. The superficial morphology and internal structure of core–sheath fibers were optimized by increasing the flow rate of the middle working fluid. Although the prepared fibers were hydrophobic initially, the core–sheath structure endowed fibers with better water retention property than monolithic fibers. Core–sheath fibers had flatter sustained-release profiles than monolithic fibers, especially for thick shell layers, which had almost zero-order release for almost 60 h. The shell thickness and sustained release of drugs brought about a good antibacterial effect to materials. The control of flow rate during fiber preparation is directly related to the shell thickness of core–sheath fibers, and the shell thickness directly affects the controlled release of drugs. The fiber preparation strategy for the precise control of core–sheath structure in this work has remarkable potential for modifying water-insoluble drug release and improving its antibacterial performance.

Microbial Poly-γ-Glutamic Acid (γ-PGA) as an Effective Tooth Enamel Protectant

Poly-γ-glutamic acid (γ-PGA) is a bio-derived water-soluble, edible, non-immunogenic nylon-like polymer with the biochemical characteristics of a polypeptide. This Bacillus-derived material has great potential for a wide range of applications, from bioremediation to tunable drug delivery systems. In the context of oral care, γ-PGA holds great promise in enamel demineralisation prevention. The salivary protein statherin has previously been shown to protect tooth enamel from acid dissolution and act as a reservoir for free calcium ions within oral cavities. Its superb enamel-binding capacity is attributed to the L-glutamic acid residues of this 5380 Da protein. In this study, γ-PGA was successfully synthesised from Bacillus subtilis natto cultivated on supplemented algae media and standard commercial media. The polymers obtained were tested for their potential to inhibit demineralisation of hydroxyapatite (HAp) when exposed to caries simulating acidic conditions. Formulations presenting 0.1, 0.25, 0.5, 0.75, 1, 2, 3 and 4% (w/v) γ-PGA concentration were assessed to determine the optimal conditions. Our data suggests that both the concentration and the molar mass of the γ-PGA were significant in enamel protection (p = 0.028 and p < 0.01 respectively). Ion Selective Electrode, combined with Fourier Transform Infra-Red studies, were employed to quantify enamel protection capacity of γ-PGA. All concentrations tested showed an inhibitory effect on the dissolution rate of calcium ions from hydroxyapatite, with 1% (wt) and 2% (wt) concentrations being the most effective. The impact of the average molar mass (M) on enamel dissolution was also investigated by employing commercial 66 kDa, 166 kDa, 440 kDa and 520 kDa γ-PGA fractions. All γ-PGA solutions adhered to the surface of HAp with evidence that this remained after 60 min of continuous acidic challenge. Inductively Coupled Plasma analysis showed a significant abundance of calcium ions associated with γ-PGA, which suggests that this material could also act as a responsive calcium delivery system. We have concluded that all γ-PGA samples tested (commercial and algae derived) display enamel protection capacity regardless of their concentration or average molar mass. However, we believe that γ-PGA D/L ratios might affect the binding more than its molar mass.