Electrospinning Machine Resources

Simultaneous photo-induced cross-linking and silver nanoparticle formation in a PVP electrospun wound dressing 2021-03-22

Poly(N-vinylpyrrolidone) (PVP) nanofiber mats were electrospun from a solution containing silver nitrate and 254 nm UV light was used to, simultaneously, photo-crosslink the polymer and promote silver nanoparticles (AgNP) formation. PVP cross-linking gives rise to a peak at 290 nm in the UV–Vis spectrum while the surface plasmon resonance of AgNP appeared at 420 nm. PVP-AgNP mats showed inhibitory effects on bacteria and fungi. This work shows that a PVP-AgNP wound dressing that ensures antimicrobial protection can be produced following a simple route.

Electrospun polyurethane-dextran nanofiber mats loaded with Estradiol for post-menopausal wound dressing 2021-03-22

Post-menopausal wound care management is a substantial burden on health services, since there are an increased number of elderly populations linked with age-related delayed wound healing. The controlled estrogen replacement can accelerate healing of acute cutaneous wounds, linked to its potent anti-inflammatory activity. The electrospinning technique can be used to introduce the desired therapeutic agents to the nanofiber matrix. So here we introduce a new material for wound tissue dressing, in which a polyurethane–dextran composite nanofibrous wound dressing material loaded with β-estradiol was obtained through electrospinning. Dextran can promote neovascularization and skin regeneration in chronic wounds. This study involves the characterization of these nanofibers and analysis of cell growth and proliferation to determine the efficiency of tissue regeneration on these biocomposite polymer nanofibrous scaffolds and to study the possibility of using it as a potential wound dressing ma

Wound dressing from polyvinyl alcohol/chitosan electrospun fiber membrane loaded with OH-CATH30 nanoparticles 2021-03-22

Novel nanomaterials have been developed for antimicrobial and wound healing applications. Here, we report the preparation of a polyvinyl alcohol/chitosan (PVA/CS) nanofiber with carboxymethyl chitosan nanoparticles (CMCS-OH30 NPs) encapsulating the antibacterial peptide OH-CATH30 (OH-30). The PVA/CS nanofibers containing OH-30 NPs (NP-30-NFs) obtained via electrospinning could achieve a secondary embedded OH-30. The effect of NP-30-NFs on the release of OH-30 was investigated through high-performance liquid chromatography. The antibacterial activities of NP-30-NFs against Escherichia coli and Staphylococcus aureus were studied by bacterial plate counting. NP-30-NFs containing different concentrations of NPs were applied to mouse skin wounds to determine their effectiveness in promoting wound healing. Results showed that NP-30-NFs exhibited antibacterial properties and promoted skin wound healing.

Fabrication and stability investigation of bio-inspired superhydrophobic surface on nitinol alloy 2021-03-22

In this paper, superhydrophobic surfaces were fabricated on nitinol alloy by utilizing nanosecond laser and silanization process. Grid pattern surfaces are obtained by adjusting the adjacent scanning path from 60 μm to 100 μm and increasing 10 μm by step, which named g60, g70, g80, g90 and g100 respectively. Silanization process is performed to achieve surface chemical modification to lower the surface energy. The water contact angle (WCA) measurements show that g80 surfaces has the largest WCA which is 154.42°±2.1° and g60 has the smallest WCA which is 152.16°±1.25°. The chemical stability against acid, alkaline, organic solvent and salt water and thermal stability of surfaces are also investigated. The results show that modified superhydrophobic nitinol surfaces have a strong stability against acid solution, organic solvent and salt water, but slightly weak stability against alkaline solution. Furthermore, modified surfaces can keep superhydrophobicity under 150 °C, and hydrophobicit

Electrospinning nanoparticles may be used to treat skin cancer 2021-03-22

Nanoparticles offer new opportunities for the treatment of skin diseases. The barrier function of the skin poses a significant challenge for nanoparticles to permeate into the tissue, although the barrier is partially compromised in case of injury or inflammation, as in the case of skin cancer. This may facilitate the penetration of nanoparticles. Extensive research has gone into developing nanoparticles for topical delivery; however, relatively little progress has been made in translating them to the clinic for treating skin cancers. We summarize the types of skin cancers and practices in current clinical management. The review provides a comprehensive outlook of the various nanoparticle technologies tested for topical therapy of skin cancers and summarizes the obstacles that impede its progress from the bench-to-bedside. The review also aims to provide an understanding of the pathways that govern nanoparticle penetration into the skin and a critical analysis of the approaches used to

Thermosensitive nanofibers loaded with ciprofloxacin as antibacterial wound dressing materials 2021-03-20

To obtain wound dressings which could be removed easily without secondary injuries, we prepared thermoresponsive electrospun fiber mats containing poly(di(ethylene glycol) methyl ether methacrylate) (PDEGMA). Blend fibers of PDEGMA and poly(l-lactic acid-co-ε-caprolactone) (P(LLA-CL) were fabricated via electrospinning, and analogous fibers containing the antibiotic ciprofloxacin (CIF) were also prepared. Smooth cylindrical fibers were obtained, albeit with a small amount of beading visible for the ciprofloxacin-loaded fibers. X-ray diffraction showed the drug to exist in the amorphous physical form post-electrospinning. The composite fibers showed distinct thermosensitive properties and gave sustained release of CIF over more than 160 h in vitro. The fibers could promote the proliferation of fibroblasts, and by varying the temperature cells could easily be attached to and detached from the fibers. Antibacterial tests demonstrated that fibers loaded with ciprofloxacin were effective in

Superhydrophobic polyaniline/polystyrene micro/nanostructures as anticorrosion coatings 2021-03-20

In this paper, superhydrophobic polyaniline (PANI)/polystyrene (PS) micro/nanostructures were prepared by an electrospinning combining with drop-cast strategy for protecting carbon steel. The corrosion resistance ability and durance property of the resultant PANI/PS micro/nanostructures in 0.1 M H2SO4 were investigated and compared using electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization technique. It is found out that effective anticorrosion performance can be provided by PANI/PS micro/nanostructures for carbon steel, and the corrosion protection efficiency (η) increases along with the water repellency of the PANI/PS micro/nanostructures. The protection properties of PANI/PS micro/nanostructures increased along with their water repellency. The PANI-PFOA/PS micro/nanostructures has the water contact angle value as high as 153°, demonstrating the most excellent anticorrosion properties with a promising anticorrosion efficiency of 99.48%.

Studies on soy protein isolate/polyvinyl alcohol hybrid nanofiber membranes as multi-functional eco-friendly filtration materials 2021-03-20

A biodegradable and multifunctional air filtration membrane was prepared by electrospinning of soy protein isolate (SPI)/polyvinyl alcohol (PVA) system in this paper. The optimized SPI/PVA proportion in the spinning solution was determined according to the analyses of microstructure, surface chemical characteristic and mechanical property of the hybrid nanofiber membranes. Under the preferred preparation condition, two kinds of polymer materials displayed a good compatibility in the hybrid nanofibers, and a large number of polar groups existed in the membrane surface. The loading filtration efficiency of the nanofiber membrane with optimal material ratio and areal density can reach 99.99% after test of 30 min for fine particles smaller than 2.5 μm in the case of small pressure drop. Besides, this kind of filtration membrane showed an antimicrobial activity to Escherichia coli in the study. The SPI/PVA hybrid nanofiber membrane with proper material composition and microstructure can be

Self-assembly of thermoresponsive nanocomposites and their applications for sensing daunorubicin with DNA 2021-03-20

Poly(N-isopropylacrylamide)-co-poly(methylmethacrylate) (PNIPAM-co-PMMA) nanofibers were fabricated by electrospinning. The titanium dioxide (TiO2) nanoparticles that grafted with thermoresponsive poly(N-isopropylacrylamide) (PNIPAM-gTiO2) were synthesized in our previous report (Gong et al., J. Mater. Chem. 22 (2012) 16872–16879). The blends of PNIPAM-co-PMMA nanofibers with PNIPAM-g-TiO2 nanoparticles (PNIPAM-g-TiO2/PNIPAM-co-PMMA) have been characterized and utilized as detection for daunorubicin. The biorecognition of daunorubicin was measured by electrochemical analysis. Because of the surface grafting polymer, both the nanocomposites of PNIPAM-g-TiO2/PNIPAM-co-PMMA and the PNIPAM-g-TiO2 nanoparticles have remarkable enhancement effect on the biorecognition of daunorubicin. Moreover, with the adding DNA, the biorecognition of the daunorubicin can be enhanced from 4% to 31.1%. It was found the self-assembly process occurred amongst the nanocomposites, daunorubicin and the DNA as th

Recent advances in polymeric scaffolds containing carbon nanotube and graphene oxide for cartilage and bone regeneration 2021-03-20

Bone and cartilage defects may occur for various reasons such as degenerative, surgical, and traumatic diseases. Autograft and allograft transplantations have the inherent problems of donor tissue and risks of infection. Tissue engineering is a combination of scaffolds, cells, and bioactive molecules for the regeneration of injured tissue. Among various advanced materials, graphene oxide (GO) and carbon nanotubes (CNTs) have widely been examined for their potential in tissue engineering primarily due to their extraordinary physicochemical and mechanical properties as well as acceptable biocompatibility. Therefore, they have been used for cell proliferation, chondrogenic differentiation, and bone regeneration. In biomedical research, artificial three-dimensional (3D) biomaterials have been advanced for treating bone and cartilage defects. CNT and GO as promising materials can serve a similar microenvironment for the natural function of bone and cartilage such as mechanical strength. A v

Influence of chitosan and hydroxyapatite incorporation on properties of electrospun PVA/HA nanofibrous mats for bone tissue regeneration: Nanofibers optimization and in-vitro assessment 2021-03-20

3D-scaffolds composed of polyvinyl alcohol-hyaluronan (PVA/HA) nanofiber mats were fabricated by electrospinner. Spinning conditions of PVA/HA were optimized for obtaining uniform and smooth nanofibers (NFs). Resultant NFs were investigated by SEM, FT-IR and mechanical tensile. Chitosan was incorporated into NFs mats during spinning for reducing bleeding, microbial growth of wound bed, and enhancing viability/proliferation of cells in damaged tissues. Hydroxyapatite (HAP) after silanization using (3-aminopropyl)triethoxysilane (APTES) was also incorporated into scaffolds due to its similar chemical composition with mineral composition of bone, which stimulates interactions between bone tissue and biomaterial resulting in a prominent interface after implantation. NFs with different compositions were bio-evaluated in vitro using antimicrobial activity, hemolysis(%), cytotoxicity, and cell adhesion tests. Results revealed that, addition of HAP into PVA/HA mats improved significantly their

Identification of the glucosamine kinase in the chitinolytic pathway of Thermococcus kodakarensis 2021-03-20

Although the chitinolytic pathway of the hyperthermophilic archaeon Thermococcus kodakarensis is well-studied, the genome does not contain genes homologous to previously identified glucosamine kinase genes. As some ADP-dependent glucokinases in the order Thermococcales exhibit phosphorylation activities for both glucose and glucosamine in vitro, the homolog in T. kodakarensis, encoded by TK1110, was selected as a candidate for the missing glucosamine kinase gene. The purified, recombinant TK1110 enzyme exhibited phosphorylation activities for not only glucose but also glucosamine and N-acetylglucosamine. Kinetic analysis indicated that activity towards glucosamine was as significant as that towards glucose. In order to determine the physiological role of TK1110 in the chitinolytic pathway of T. kodakarensis, a gene disruption strain of TK1110 was constructed. When grown in chitin-containing medium, the TK1110 disruption resulted in almost complete impairment in chitin degradation, and

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