Search Results (72)

The global crisis concerning multidrug-resistant microorganisms necessitates the development of innovative antimicrobial strategies that avoid conventional antibiotics and overcome the toxicity and environmental persistence associated with traditional metal-based biocides. This work aims to develop safe and sustainable antibacterial filtration materials by integrating cationic hyperbranched polymer dendrimers (HBP) into electrospun nanofibers. Cationic HBPs were successfully embedded into recycled polyamide 6 nanofibers using industrial needleless electrospinning. Filtration efficiency, assessed against a 0.3 µm paraffin oil aerosol according to EN 149:2001, consistently exceeded 99.8%, meeting and surpassing the FFP3 classification threshold while maintaining low air resistance. The HBP-functionalized nanofibers exhibited pronounced contact-active antibacterial activity against Staphylococcus aureus and Escherichia coli. Quantitative plate count assays confirmed viability reductions of up to 74.1% after 2 h of co-incubation. Crucially, the absence of inhibition zones in agar diffusion tests confirmed that the active polymer was stably embedded within the nanofiber matrix and did not leach. Comprehensive toxicological tests, including cell line and 3D human skin and airway tissue models, confirmed the material’s safety for both dermal and respiratory contact. This study presents a scalable, metal-free, and environmentally responsible next-generation filtration system that combines high mechanical efficiency with active antimicrobial functionality. Full article

Background: Seasonal influenza remains a significant public health problem, and the constant antigenic drift of viruses requires regular vaccine updates. mRNA vaccines offer a promising platform for the development of new, effective influenza vaccines. Administration of the naked mRNA vaccine using a needle-free jet injection system further enhances its safety, reduces cost, and eliminates the need for lipid nanoparticles, which are traditionally used for mRNA delivery. Lyophilization of naked mRNA allows for long-term storage at +4 °C. Methods: We designed and produced an mRNA vaccine against seasonal influenza, designated mRNA-Vector-Flu, encoding the hemagglutinin (HA) of the A/Wisconsin/67/2022(H1N1)pdm09, A/Darwin/9/2021(H3N2), and B/Austria/1359417/2021 strains. The vaccine was lyophilized and stored for 1 month in a refrigerator (+4 °C). A comparative immunogenicity study was conducted between synthesized immediately before use prepared and lyophilized naked mRNA-Vector-Flu. The preparations were administered to BALB/c mice using a jet needleless injection twice, 3 weeks apart. Immunogenicity was assessed on day 35 of the study. Results: A comparative immunogenicity study of naked mRNA-Vector-Flu demonstrated that both the synthesized immediately before use prepared formulation and the lyophilized form, stored at +4 °C for a month, induced similar levels of virus-specific antibodies and generated a pronounced T-cell immune response. Conclusions: Delivery of the naked mRNA vaccine using a needle-free jet injection ensures a high-level immune response, which improves its safety, reduces its cost, and eliminates the need for lipid nanoparticles traditionally used for mRNA delivery. At the same time, lyophilization of the naked mRNA vaccine preserves its biological activity and ensures its storage for at least a month at +4 °C temperatures. Our results demonstrate that our proposed approach can be considered a promising direction for the development and improvement of the mRNA vaccine platform. Full article

This study presents a comprehensive investigation into the large-scale production of synthetic and hybrid (nanoparticle-loaded) nanofibers using needleless electrospinning. A diverse range of polymers, including polyamide 6 (PA6) and its other polymer combinations, recycled PA6, polyamide 11 (PA11), polyamide 12 (PA12), polyvinyl butyral (PVB), polycaprolactone (PCL), polyacrylonitrile (PAN), polyvinylidene fluoride (PVDF), polyurethane (PU), polyvinyl alcohol (PVA), and cellulose acetate (CA), were utilized to fabricate nanofibers with tailored properties such as polymer solution concentrations and various solvent systems. Furthermore, an extensive variety of nano- and micro-particles, including TiO₂, ZnO, MgO, CuO, Ag, graphene oxide, CeO₂, Er₂O₃, WO₃, MnO₂, and hyperbranched polymers, were incorporated into the polymeric systems to engineer multifunctional nanofibers with enhanced structural characteristics. The study examines the impact of polymer–nano/micro-particle interactions, fiber morphology, and the feasibility of large-scale production via needleless electrospinning. The resulting nanofibers exhibited diameters starting from 80 nm, depending on the polymer and processing conditions. The incorporation of TiO₂, CeO₂, WO₃, Ag, and ZnO nanoparticles into 15% PA6 solutions yielded well-dispersed hybrid nanofibers. By providing insights into polymer selection, nano- and micro-particle integration, and large-scale production techniques, this work establishes a versatile platform for scalable hybrid nanofiber fabrication, paving the way for innovative applications in nanotechnology and materials science. Full article

Background/Objectives: Human parainfluenza virus type 1 (hPIV-1) is a major cause of serious respiratory diseases in young children. Annually, hPIV-1 results in approximately 10,000 hospitalizations in the United States due to croup, bronchiolitis, and/or pneumonia, and 10,000 deaths worldwide due to acute lower respiratory tract infections among children less than 5 years of age. Despite the burden of disease, no vaccine for hPIV-1 is currently approved. Sendai virus (SeV) is a murine PIV-1. It has structural similarities with hPIV-1 and is currently under clinical development as an hPIV-1 Jennerian vaccine. Attributes of SeV include the following: (a) needleless delivery, (b) rapid and durable serum antibody responses after a single intranasal administration, (c) durable IgG and IgA responses in the nasal mucosa, and (d) use as a platform for recombinant vaccines against multiple pediatric pathogens. Evaluation of the tolerability, safety, and immunogenicity of intranasal SeV in healthy adults and seropositive children 3 to 6 years of age was previously conducted and supported vaccine advancement to evaluation in younger children. Methods: Three seropositive children 1 to 2 years of age received a single intranasal dose of 5 × 10⁵ EID₅₀ SeV (SENDAI, Clinicaltrials.gov NCT00186927). Adverse events were collected for 28 days post-vaccine administration using diary cards and participants were followed for six months in total. Sera were collected longitudinally for clinical laboratory and virus-specific antibody tests. Nasal swabs were collected longitudinally for virus and mucosal antibody tests. Results: Intranasal SeV was well tolerated, with only mild grade 1–2 events that resolved spontaneously. No serious adverse events, medically attended adverse events, or adverse events causing protocol termination were reported. One participant had positive nasal swabs for inoculated SeV during the first week after vaccination. Although children had measurable PIV-1-specific serum antibodies at baseline, intranasal SeV vaccination resulted in significant serum antibody increases in all participants. Similarly, there were significant increases in PIV-1-specific nasal IgG and IgA levels in all participants. Elevated antibody levels persisted through the six months of follow-up. Conclusions: Intranasal SeV was well tolerated and uniformly immunogenic in seropositive children 1 to 2 years of age. Results encourage the further evaluation of SeV and SeV-based recombinants as potential intranasal vaccines for the prevention of infection by hPIV-1 and other serious respiratory pathogens. Full article

Electrospinning is a technique to produce nanofiber mats for diverse applications. In biomedicine in particular, the addition of an antibacterial agent can be advantageous. Here, we report on the needleless electrospinning of nanofiber mats using poly(acrylonitrile) (PAN) blended with different mushroom mycelium powders, which have antibacterial and other functional properties. While PAN blended with Pleurotus ostreatus (oyster mushroom) powder could be electrospun well, PAN blended with Ganoderma lucidum (reishi mushroom) powder was nearly impossible to spin. The PAN/P. ostreatus nanofiber mats showed a morphology after electrospinning similiar to pure PAN; however, the carbon yield was lower. This indicates the possibility of embedding P. ostreatus powder in PAN nanofiber mats for biotechnological or biomedical applications. Full article

A multi-vane and multi-slit electrospinning nozzle for diversion was proposed to respond to the issues of easiness of clogging, existing End Effect among needles in current multi-needle electrospinning, and uncontrollable Taylor cone position in needleless electrospinning. The upper part of the novel nozzle is a cylindrical straight pipe, and the lower part is a flow channel expansion structure composed of multiple vane components that spread outward at an angle. Ansys software was used to study the effect of different opening angles of the vanes on the spreading of the electrospinning solution. In the fluid simulation, for the novel nozzle with a central slit and a support structure, when the vanes have an opening angle of 35° and a length of 11 mm, the droplet holding time is 16 s, twice as long as the nozzle without support (8 s). This result corresponds to the subsequent droplet holding experiment, showing that the support structure aids droplet holding and enhances electrospinning stability. Comsol Multiphysics software was used to investigate the effect of the vanes’ parameters on the uniformity of the electric field. The results indicate that when the vanes of the new electrospinning nozzle are set at an opening angle of 35°, with four vanes each 11 mm in length, a receiving distance of 200 mm, and a voltage of 30 kV, the novel nozzle achieves an average electric field intensity of 5.26 × 10⁶ V/m with a CV value of 6.93%. Metal 3D printing was used to create a new nozzle for electrospinning, which successfully produced stable multiple jets and increased nanofiber output. Full article

Casein is a natural milk protein that has been investigated for various applications. Casein nanofibers are of great interest for tissue engineering. Spinning casein alone has proven difficult due to its unsuitable viscoelasticity and extensive intermolecular interactions. Our study aims at optimizing casein/poly(ethylene oxide) (PEO) spinning solutions for needleless electrospinning. For this purpose, PEO with different molecular weights was mixed with different caseins in different ratios and processed with different spinning parameters. Scanning electron microscopy (SEM) images show the impact of these parameters on the diameter distribution and morphology of the nanofibers. The paper gives the first overview of the optimum spinning parameters for wire-based electrospinning of casein/PEO nanofiber mats that are mostly standard values (maximum electrode–electrode distance, carriage speed of 100 mm/s, and PEO with 300 kDa molecular weight), combined with the addition of beeswax to improve fiber morphology and reduce beads. Full article

Transdermal drug delivery minimizes pain and provides a controlled, stable release of drugs, but its effectiveness is limited by the skin’s natural barriers. Microneedles overcome this problem, enabling minimally invasive drug delivery. Microneedle patches (MNPs) with 80 µm-tall needles composed of hyaluronic acid (HA) were developed and evaluated for their formability, structural integrity, dissolution rate, skin penetration ability, and drug transmission capacity. The influence of the molecular weight of HA on these properties was also investigated. MNPs made from low-molecular-weight HA (30 kDa–50 kDa) demonstrated 12.5 times superior drug permeability in ex vivo human skin compared to needleless patches (NLPs). Furthermore, in the same test, low-molecular-weight HA MNPs had 1.7 times higher drug permeability than high-molecular-weight HA MNPs, suggesting superior transdermal administration. The molecular weight of HA significantly influenced its solubility and permeability, highlighting the potential effectiveness of MNPs as drug delivery systems. Puncture tests demonstrated a penetration depth of 50–60 µm, indicating minimal nerve irritation in the dermis and effective drug delivery to the superficial dermal layer. These results present a manufacturing technique for MNPs incorporating model drug compounds and highlight their potential as a novel and minimally invasive drug delivery method for the biomedical applications of soft gels. Full article

Background: Hydrogen gas (H₂) has been shown to be effective in the treatment of various clinical conditions, from acute illnesses to chronic illnesses. However, its clinical indications and the corresponding appropriate hydrogen delivery methods have yet to be determined. This is due to the fact that the pharmacokinetics and pharmacodynamics of hydrogen in each delivery method have not been experimentally proven. Here, we verified the pharmacokinetics of hydrogen after the infusion of hydrogen-saturated saline. Methods: Hydrogen-saturated saline was prepared and checked for sterility and component specifications. Hydrogen-saturated saline was administered intravenously (125 mL/h) through the left internal jugular vein of pigs, and the blood hydrogen concentration was measured over time. Results: It was confirmed that hydrogen can be safely mixed under pressure into intravenous solutions (pharmaceutical products) without the contamination of foreign substances by using a needle-less vial access cannula. No change in the PH or composition of the solution was observed due to hydrogen filling. The hydrogen concentrations of blood samples collected from the left internal jugular vein 3 cm to the heart from the tip of the infusion line were 6.4 (30 min), 4.7 (60 min), 4.9 (90 min), and 5.3 (120 min) ppb w/w, respectively. The hydrogen concentrations of blood samples collected from the right atrium were 0.7 (30 min), 0.5 (60 min), 0.7 (90 min), and 0.7 (120 min) ppb, respectively. The hydrogen concentration of blood samples collected from the right internal carotid artery were 0.1 (pre), 0.2 (30 min), 0.3 (60 min), 0.0 (90 min), and 0.0 (120 min) ppb w/w, respectively. Conclusions: We confirmed that hydrogen could be safely pressurized and filled into intravenous (pharmaceutical) solution without contamination by foreign objects using a needle-free vial access cannula. When saturated hydrogen saline was dripped intravenously, almost all of the hydrogen was expelled during its passage through the lungs and could not be supplied to the arterial side. Full article

Electrospinning of polymer material has gained a lot of interest in the past decades. Various methods of electrospinning have been applied for different applications, from needle electrospinning to needleless electrospinning. A relatively new variation of electrospinning, namely near-field electrospinning, has been used to generate well-defined patterns. This variation of electrospinning, also known as near-field direct-write electrospinning, allows for precise control of the fiber deposition, sacrificing on the thickness of the resulting fibers. Typically, for this method, melt electrospinning is preferred, since it provides a higher viscosity of the polymer and thereby better control of the fiber deposition. However, when mixing additives into the spinning dope, a solution spinning approach is preferable since it provides a more homogeneous distribution of the additives in the spinning dope. A fluorescent spinning dope of dissolved PET with fluorescent carbon quantum dots has been used to generate the fluorescent patterns. These can be used to generate logos, bar codes, or QR codes to encode information about the material, such as watermarks or counterfeiting tags. Full article

The high accumulation of plastic waste in the environment has led to great interest in biodegradable polymers, such as polylactic acid (PLA) or polyhydroxyalkanoates (PHAs). Their benefits, combined with the application of electrospinning technology, represent an innovative proposal for the food packaging industry. This article provides a comprehensive review of the latest developments of PLA- and PHA-biopolyester-based electrospun materials for food packaging applications, summarizing the reported technologies, material properties, applications, and invention patents. In addition, the legislation used to assess their biodegradability is also detailed. Electrospun packaging materials are largely developed through uniaxial, coaxial, emulsion, multiaxial, and needleless techniques. PLA- and PHA-biopolyester-based electrospun materials can be obtained as single and multilayer packaging structures, and the incorporation of natural extracts, organic compounds, and nanoparticles has become a great strategy for designing active food packaging systems. The biodegradability of electrospun materials has mainly been evaluated in soil, compost, and aquatic systems through ASTM and ISO normatives. In this review, the dependence of the biodegradation process on the polymer type, conditions, and test methods is clearly reviewed. Moreover, these biodegradable electrospun materials have shown excellent antioxidant and antimicrobial properties, resulting in a great method for extending the shelf life of fruits, bread, fish, and meat products. Full article

Nanofiber mats with a high surface-to-volume ratio can be prepared by electrospinning. The Porosity is sometimes reported to be tunable by blending different materials, e.g., water-soluble poly(ethylene oxide) (PEO) with not water-soluble poly(acrylonitrile) (PAN). Here, nanofiber mats were electrospun from different PAN:PEO ratios, using a wire-based electrospinning machine “Nanospider Lab”. Investigations of the as-spun nanofiber mats as well as of membranes after washing off the water-soluble PEO by scanning electron microscopy (SEM) revealed severe differences in the nanofiber mat morphologies, such as varying fiber diameters and especially non-fibrous areas in the carbonized nanofiber mats, depending on the amount of PEO in the nanofiber mat as well as the molecular weight of the PEO. Similarly, the ratio and molecular weight of PEO influenced the results of stabilization and carbonization. This paper discusses the possibility of tailoring nanofiber porosity for the potential use of PAN nanofiber mats in tissue engineering, filtration, and other applications. Full article

Bradymonabacteria, as the representative of the facultative prey-dependent predators, were re-classified from the preceding Deltaproteobacteria into the phylum Myxococcota and proposed as a novel class named Bradymonadia. However, it was ambiguous whether their predatory pattern and properties were similar to those of the other myxobacterial predators. Therefore, the physiologic features were compared to determine the similarities and differences during the process of group attack and kin discrimination. Comparative genomic analyses were performed to conclude the core genome encoded commonly by bradymonabacteria, Myxococcia, and Polyangia. In conclusion, we proposed that bradymonabacteria have a predation pattern similar to the that of the representative of opportunistic predators like Myxococcus xanthus but with some subtle differences. Their predation was predicted to be initiated by the needle-less T3SS*, and the S-motility mediated by T4P also participated in the process. Meanwhile, their group attacks relied on cell contact and cell destiny. Inter-species (strains) kin discriminations occurred without the existence of T6SS. However, no extracellular lethal substance was detected in the fermentation liquor culture of bradymonabacteria, and the death of prey cells could only be observed when touched by their cells. Moreover, the prey-selective predation was observed when the predator encountered certain prey from Bacillus (G⁺), Algoriphagus (G⁻), and Nocardioides (G⁺). Bradymonabacteria can be regarded as a potential consumer and decomposer, and preying on many sea-dwelling or human pathogenic bacteria allows this group a broad application prospect in marine culture and clinical disease control. Our study will provide more evidence for its exploitations and applications. Full article

Needle-free buccal anesthesia improves dental treatment outcomes for both patients and dentists. In this study, we report on an assessment of the enhancement effects of α-bisabolol on the in vitro transmucosal permeation of prilocaine hydrochloride (PCl) and lidocaine hydrochloride (LCl) from needleless buccal films. We also evaluated the mechanical properties of the film, which consisted of Methocel™ K100 LV as the film-forming polymer (3% m·m⁻¹), PEG 400 as a cosolvent (15% m·m⁻¹ based on drug loading), α-bisabolol (15 and 30% m·m⁻¹ based on drug loading), and the drugs combined at a 1:1 ratio (15 mg·unit⁻¹). The porcine esophageal epithelium was used as a membrane barrier, and artificial saliva was the release medium. After a 1 h experiment at 25 ± 2 °C, α-bisabolol significantly decreased, rather than enhanced, the permeation fluxes (five-fold), permeability coefficients (seven-fold), and retentions (two-fold) of both PCl and LCl through the epithelium, regardless of the concentration. Moreover, the resistance and flexibility of the films markedly decreased compared to those without α-bisabolol. Therefore, under the experimental conditions, using α-bisabolol as a buccal permeation enhancer for the hydrophilic local anesthetics PCl and LCl from buccal films is not feasible. Full article

Skin aging is associated with both intrinsic and extrinsic aging, with extrinsic aging caused by environmental factors and overlaying the effects of chronological aging. The main aim of this study was to evaluate the effect of preparations containing Helix aspersa snail mucus on skin regeneration with photoaging features. Before and 3 months after the series of treatments, skin biopsy specimens from the right preauricular region of the face were taken from six women. Histological, morphometric, and immunohistochemical analyses were performed. Positive changes, indicating a reduction in photoaging related to the reduction in epidermis thickness 3 months after the end of the treatments, were noted in each group. A statistically significant increase in the thickness of the collagen fiber bundles was also observed in the patients 3 months after a series of micro-needle mesotherapy treatments with snail mucus and 0.9% NaCl. There was a significant increase in the immuno-expression of Ki-67 and PCNA in the dermis. The aforementioned significance applies to patients in whom snail mucus was introduced with the use of micro-needle mesotherapy and needle-free mesotherapy. Moreover, a statistically significant increased area with the immunoexpression of MMP-2 in the dermis was observed in the above-mentioned groups of patients, who were treated with the preparation containing snail filtrate. The results of the study suggest that the use of snail mucus preparations for skincare, as well as its introduction by micro-needle and needleless mesotherapy, had a beneficial effect on the condition of the skin. Full article