Antibacterial Fibers Research Articles

Preparation and Property Analysis of Antibacterial Fiber Membranes Based on Hyperbranched Polymer Quaternary Ammonium Salts.

Due to their excellent properties, antimicrobial fiber membranes are widely applied in bioprotective materials. This work addresses the preparation of thermoplastic polyurethane (TPU)-based fiber membranes with active antimicrobial properties. 2-hydroxypropyl trimethyl ammonium chloride-terminated hyperbranched polymer (HBP-HTC) was synthesized and used as an antimicrobial agent. The fiber membranes were obtained by electrospinning a mixed solution of HBP-HTC and TPU. Different electrospinning conditions were investigated, such as the spinning voltage and drum rotation speed. The fiber membrane prepared under a 22 kV anode voltage and 100 rpm rotation speed had an average fiber diameter of 1.66 μm with a concentrated diameter distribution. Antibacterial tests showed that when the fiber membrane was loaded with 1500 mg/kg of HBP-HTC, the antibacterial rates of E. coli as well as S. aureus both reached 99.99%, exhibiting excellent proactive antimicrobial performance. Moreover, the protective performance of the fiber membrane was outstanding, with a filtration efficiency of 99.9%, a hydrostatic pressure resistance greater than 16,758 Pa, and a moisture permeability of 2711.0 g⋅(m2⋅d)-1.

Wound Dressings from Electrospun Gelatin Fibres Coated with Zinc Oxide nano Particles

Traditional wound dressings require frequent replacement, are prone to bacterial growth and cause a lot of environmental pollution. Therefore, biodegradable and antibacterial dressings are eagerly desired. In this paper, gelatin/ZnO fibers were first prepared by side-by-side electrospinning for potential wound dressing materials. The morphology, composition, cytotoxicity and antibacterial activity were characterized by using Fourier transform infrared spectroscopy (FTIR), X-ray diffractometry (XRD), particle size analyzer (DLS), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), thermogravimetry (TGA) and Incucyte™ Zoom system. The results show that ZnO particles are uniformly dispersed on the surface of gelatin fibers and have no cytotoxicity. In addition, the gelatin/ZnO fibers exhibit excellent antibacterial activity against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) with a significant reduction of bacteria to more than 90%. Therefore, such a biodegradable, nontoxic and antibacterial fiber has excellent application prospects in wound dressing.

Preparation and Performance of an Antibacterial Fiber Mat with High Breathability and Moisture Permeability Based on Electrospinning

Preparation and Performance of an Antibacterial Fiber Mat with High Breathability and Moisture Permeability Based on Electrospinning

Edible antibacterial gelatin/zein fiber films loaded with cinnamaldehyde for extending the shelf life of strawberries by electrospinning approach

Strawberries are a kind of nutritious fruit but they are easily spoilt by mold. Therefore, it is significant to prolong the shelf life of strawberries for the avoidance of their numerous wastes. To achieve the aforementioned objective, in this paper, the edible and biodegradable natural polymers of gelatin/zein were used to prepare the antibacterial fiber films loaded with cinnamaldehyde by electrospinning method. The fibers prepared in this study were smooth and bead-free, with the average diameters ranging from 1.46 to 2.02 μm. The successful encapsulation of cinnamaldehyde in obtained fiber films was confirmed by Fourier transform infrared spectra. The prepared fiber films decomposing at about 230 °C were shown by thermogravimetric analysis curves, indicating their high thermal stability. The amorphous structure of the polymers in the produced fiber films was displayed by X-ray diffraction curves. Compared with the untreated strawberries, strawberries treated with fiber films encapsulated with 15 wt% and 20 wt% cinnamaldehyde showed the smallest changes in appearance, weight loss rate, hardness, pH, and total soluble solids at 6 d. The shelf life of strawberries was increased to 6 days by the fiber films containing 15 wt% and 20 wt% cinnamaldehyde. The fiber films prepared in this study were potentially expected to be used as edible antibacterial packaging films, nutrient and drug carriers.

Preparation of Antibacterial Biobased Fibers by Triaxial Microfluidic Spinning Technology Using Ionic Liquids as the Solvents.

Bacterial infections have become a serious threat to public health. The utilization of antibacterial textiles offers an effective way to combat bacterial infections at the source, instead of relying solely on antibiotic consumption. Herein, efficient and durable antibacterial fibers based on quercetin and cellulose were prepared by a triaxial microfluidic spinning technology using ionic liquids (ILs) as the solvents. It was indicated that the structure and properties of the antibacterial fibers were affected by the type of IL and the flow rates during the triaxial microfluidic spinning process. Quercetin regenerated from [Emim]Ac underwent structural transformation and obtained an increased water solubility, while quercetin regenerated from [Emim]DEP remained unchanged, which was proven by FI-IR, XRD, and UV analyses. Furthermore, antibacterial fibers regenerated from [Emim]Ac exhibited the highest antibacterial activity of 96.9% against S. aureus, achieved by reducing the inner-to-outer flow rate ratio to 0 and concentrating quercetin at the center of fibers. On the other hand, when [Emim]DEP was used as the solvent, balancing the inner-to-outer flow rate ratio to concentrate quercetin in the middle layer of the fiber was optimal for achieving the best antibacterial activity of 93.3% because it promised both the higher encapsulation efficiency and release rate. Computational fluid dynamics (CFD) mathematically predicted the solvent exchange process during triaxial spinning, explaining the influence of IL types and flow rates on quercetin distribution and encapsulation efficiency. It was indicated that optimizing the distribution of antibacterial agents within the fibers can fully unleash its antibacterial potential while preserving the mechanical properties of the fiber. Therefore, the proposed simple triaxial spinning strategy provides valuable insights into the design of biomedical materials.

Antimicrobial fibres derived from aryl-diazonium conjugation of chitosan with Harakeke (Phormium tenax) and Hemp (Cannabis sativa) Hurd

Surface functionalisation of natural materials to develop sustainable and environmentally friendly antimicrobial fibres has received great research interest in recent years. Herein, chitosan covalent conjugation via aryl-diazonium based chemistry onto Phormium tenax fibres (PTF) and hemp hurds (HH) was investigated. PTF are fibres derived from Harakeke/New Zealand flax, an indigenous and abundant plant source of leaf fibres, which served as an important 19th century export commodity of New Zealand. HH are obtained as a by-product from the hemp (Cannabis sativa) industry and find applications as traditional construction material, animal bedding, chemical absorbent, insulation, fireboard etc. This study reports aryl-diazonium covalent attachment of chitosan and PD13 (6-O-(3-(2-(N,N-dimethylamino)ethylamino)-2-hydroxypropyl)chitosan), a chitosan derivative with improved antibacterial activity, on to PTF and HH. The modification was confirmed using FTIR, XPS, SEM and water contact angle studies. Comparison of aryl-diazonium versus the use of succinic anhydride bridging for chitosan attachment was also investigated, with the diazonium method giving improved results. The treated PTF and HH fibres had good antibacterial activity against Staphylococcus aureus and this study contributes to the development of sustainable antibacterial fibres using bio-based materials.

Blend Electrospinning of Nigella sativa-Incorporating PCL/PLA/HA Fibers and Its Investigation for Bone Healing Applications.

One of the well-known postoperative complications that requires a number of prophylactic and curative treatments is infection. The implications of postsurgical infections are further exacerbated by the emergence of antibiotic-resistant strains. Reduced effectiveness of synthetic antibiotics has led to an interest in plant-based substances. Extracts obtained from Nigella sativa have been shown to possess effective anti-infectious agents against bacteria frequently seen in bone infections. In this study, a fiber-based bone scaffold containing polycaprolactone, poly(lactic acid), and hydroxyapatite with N. sativa oil at varying concentrations was developed. Solvent electrospinning was used to fabricate the fibers with the specified composition. According to FE-SEM analysis, fibers with average diameters of 751 ± 82, 1000 ± 100, 1020 ± 90, and 1223 ± 112 nm were formed and successful integration of N. sativa oil into the fiber's structure was confirmed via FTIR. Staphylococcus aureus showed moderate susceptibility against the fibers with a maximum inhibition zone diameter of 11.5 ± 1.6 mm. MTT assay analysis exhibited concentration-dependent cell toxicity against fibroblast cells. In short, the antibacterial fibers synthesized in this study possessed antibacterial properties while also allowing moderate accommodation of CDD fibroblast cells at low oil concentrations, which can be a potential application for bone healing and mitigating postsurgical infections.

Modification of hydrophobic electrospun polyurethane fibers for efficient wound healing activity

The intricate process of wound healing demands an atmosphere that is conducive to quick healing. In this situation, creating biocompatible and antibacterial fibers may be a good choice. In this study, the unmodified polyurethane and polyurethane modified with cellulose acetate and rosemary oil were electrospun into fibers. These fibers were subsequently adsorbed using silver nanoparticles. The FE-SEM was used to characterize the fibers, revealing their defect-free morphology and the presence of nanoparticles on them. Additionally, the XRD findings demonstrated that silver nanoparticles were successfully incorporated into the spun fiber mats. The contact angle measurements indicated a decreasing behavior starting from 100.4±1° to 28.4±3° in the case of unmodified polyurethane and modified fibers. The antibacterial assay revealed that although unmodified fiber mats have negligible antibacterial action, the modified fibers exhibited considerable antibacterial activity against E. coli and S. aureus. In-vitro studies revealed that Human embryonic kidney 293T (HEK 293T) cell proliferation was enhanced on the surface of modified fibers compared to unmodified fibers. In conclusion, our research presents unique multifunctional fibrous scaffolds that are appropriate and optimal for wound healing applications.

Antibacterial fibers impregnated with mycosynthetized AgNPs for control of Pectobacterium carotovorum

Using biopolymers functionalized with antibacterial agents to manufacture active packaging is a clean alternative to mitigate food losses due to postharvest plant diseases. In this study, two mycosynthetized AgNPs impregnation methodologies on cotton (cationization and in situ biochemical reduction) were used to obtain the antibacterial fibers (A-AgNPs-C and A-AgNPs-IBR), which, in addition to being characterized by SEM-EDX, XRD, were evaluated as antibacterial materials. The cotton fibers showed growth inhibition of Pectobacterium carotovorum at 48 h. The reuse tests of these cotton fibers showed that the two types of fibers could have up to three successive uses without losing their effectiveness, regardless of the impregnation method used. Is important to highlight that the retention tests indicated that the AgNPs remain attached to the A-AgNPs-C and A-AgNPs-IBR fibers after several successive washes. Finally, the mycosynthesized AgNPs were also impregnated on fique fibers (Fique-AgNPs) by cationization to obtain little antibacterial sacks. Nanostructured materials that in in vivo tests on potatoes showed only 7.8 % of affectation, while the tubers stored in the traditional sacks had an affectation of 25 %. This immobilization of AgNPs in natural fibers will allow the development of a nanobiotechnological application in the storage and transport of potatoes, after performing some additional cytotoxicity tests to guarantee its safety.

Knitted Structures Made of Antibacterial Fibers Intended for Protective Gloves

At a time of growing epidemic hazards caused by a very rapid evolution of dangerous pathogens, there is a pressing demand for bioactive textiles. Therefore, the development of high-quality knitted structures that could be used as bioactive protective materials has become a priority. This publication describes the fabrication of functional knitted structures from previously prepared antibacterial cellulose fibers containing nanosilica with immobilized silver nanoparticles. The structural and physical parameters of knitted fabrics made from them were studied with a view to their potential application in bioactive protective gloves. Tests of the basic structural and physical parameters of the knitted fabrics did not show that the nanomodifier applied in fibers significantly impacts the physical properties of the resulting fabrics. Moreover, water vapor permeability, cut resistance, and pH test results relevant to the functional and protective properties of interest and to user comfort showed that the obtained fabrics can be used in the production of bioactive protective gloves.

Antibacterial activity of cellulose/chitosan green composite for wound healing

Cellulosic antibacterial fibers have great importance in the manufacturing of healthcare products. In this research work, antibacterial hemp and bamboo fibers were selected for manufacturing two green composite for wound healing. The chitosan was selected to get gel formation and behave as carrier in the manufacturing of cellulosic/chitosan green composite. Moreover, a water-soluble levofloxacin was included to give a release of antibacterial properties. The hemp and bamboo fibers were cleaned and fiber-to-fiber separation was done with a manual comber machine. The chitosan was solubilized using acetic acid and stirred for 12 hours to get a completely clear and viscous gel. Afterward, powder ground hemp and bamboo fibers were separately poured into two separate beakers. Two different types of composites (hemp/chitosan) and Bamboo/chitosan were transferred into petri dishes and dried in the oven at 400C for 24 hours. The samples were loaded with a levofloxacin antimicrobial agent. Both composites (hemp/chitosan, and bamboo/chitosan) were characterized for surface morphology, structural changes and antimicrobial testing against gram-positive and gram-negative bacteria. It was analyzed that without levofloxacin both cellulose/chitosan composites resisted bacteria growth and did not show inhibition zone, but samples loaded with levofloxacin displayed good antibacterial activity and showed excellent zone of inhibition against gram-positive and gram-negative bacteria. Futhermore, FTIR evidenced that there was no formation of cross linking composites, but composites were held together due to chitosan and fibers gel formation.

Constructing antibacterial surfaces with alkali treatment on polyethylene terephthalate nanofibers

Polyethylene terephthalate (PET) can prevent bacteria from adhesion by repelling the bacteria with its negatively charged surface. However, it is commonly believed that it does not have the ability to directly inactivate bacteria. Surprisingly, we have found that alkali-treated PET nanofibers, which are also negatively charged due to the carboxyl end groups, can have remarkable antibacterial properties (antibacterial rate (AR) at 89% and 75%, against S.aureus and E.coli, respectively). We find that alkali-treatment has brought increased carboxyl end groups to the surface, making the surface more negatively charged. The positively charged cetyltrimethylammonium ions (CTA+) that are used as catalysts for the alkali-treatment can form stable electrical double layers (EDL) with the carboxyl groups near the fiber surfaces, and the enriched CTA+ in EDL can efficiently inactivate the bacteria. Based on these, an effective heavy-metal free antibacterial fiber has been developed by loading iron-phthalocyanine to the nanofibers. This phthalocyanine-empowered antibacterial fiber can inactivate bacteria under dark conditions (99% AR) by the surface CTA+ and the generated weak reactive oxygen species.

Preparation and antibacterial properties of copper phthalate/polyethylene terephthalate composition fiber

Copper phthalate was employed as antibacterial agent that improve its dispersibility in polyethylene terephthalate (PET) fiber. The antibacterial activity of copper phthalate, copper terephthalate and nano-copper oxide were evaluated against Colon bacillus, Staphylococcus aureus and Candida albicans, copper phthalate showed the best antibacterial activity. The antibacterial masterbatch of copper phthalate was subsequently prepared by melt blending, which integrated into PET to prepare antibacterial fiber during the spinning process at 285 °C. The sample containing 0.3 % copper phthalate displayed great antibacterial performance and durability against Escherichia coli, Staphylococcus aureus and Candida albicans.

Wool dyeing using Ziziphus bark extract as a natural dye: studies on the dyeing, antibacterial, and antioxidant characteristics.

Considering the growing importance of natural colorants and sustainable products, the research on application of natural dyes has been focused on new color resources, identification, and standardization of natural dyes. Hence, the extraction of natural colorants available in Ziziphus bark was performed by ultrasound technique and its application on the wool yarn to produce the antioxidant and antibacterial fibers. The optimal conditions for the extraction process were as follows: ethanol/water (1/2 v/v) as solvent, concentration of Ziziphus dye 14g/L, pH 9, temperature 50°C, time 30min, and L.R ratio 50:1. Moreover, the effect of important variables for application of Ziziphus dye on the wool yarn was investigated and optimized temperature 100°C, concentration of Ziziphus dye 50% o.w.f., time for dyeing 60min and pH 8, and L.R 30:1. The reduction values of Gram-negative and Gram-positive bacteria on dyed samples at optimized condition were 85% and 76%, respectively. Moreover, the antioxidant property of dyed sample was 78%. The color variations on the wool yarn were produced with diverse metal mordants, and color fastness properties were measured. Ziziphus dye not only can be used as an origin for a natural dye, but also provided the antibacterial and antioxidant agent on the wool yarn, which can be a step towards the fabrication of green products.

Loading of ZIF‐67 on silk with sustained release of iodine as biocompatible antibacterial fibers

Antibacterial fibers have great potential in numerous applications, including bandages, surgical robes, and surgical sutures, and play a significant role in our everyday lives. Here, zeolitic imidazolate framework‐67 was synthesized using a green method on silk fibers through a layer‐by‐layer process under ultrasonic irradiation (ZIF‐67@silk [U]) and without ultrasonic irradiation (ZIF‐67@silk [B]). Then, iodine was loaded on ZIF‐67@silk samples and were assessed as antibacterial fibers with iodine release. Four samples of ZIF‐67@silk and I2@ZIF‐67@silk were characterized by FT‐IR, PXRD, FE‐SEM, TGA, BET, and UV–Vis spectroscopy. Finally, antibacterial activity of ZIF‐67@silk (B and U) and I2@ZIF‐67@silk (B and U) on Staphylococcus aureus as Gram‐positive bacteria and Escherichia coli as Gram‐negative bacteria was investigated. In addition to ZIF‐67@silk samples, iodine‐loaded samples showed excellent antimicrobial facility.

Double-Grafted PET Fiber Material to Remove Airborne Bacteria with High Efficiency.

Air pollution caused by bacteria and viruses has posed a serious threat to public health. Commercial air purifiers based on dense fibrous filters can remove particulate matter, including airborne pathogens, but do not kill them efficiently. Here, we developed a double-grafted antibacterial fiber material for the high-efficiency capture and inactivation of airborne microorganisms. Tetracarboxyl phthalocyanine zinc, a photosensitizer, was first grafted onto the polyester (PET) fiber, followed by coating with chitosan on the surface of PET fiber to make a double-grafted fiber material. Under the irradiation of light with a specific wavelength (680 nm), double-grafted fiber materials killed up to 99.99% of Gram-positive bacteria and Gram-negative bacteria and had a significant antibacterial effect on drug-resistant bacteria. The double-grafted PET fiber showed broad-spectrum antibacterial activities and was capable to inactivate drug-resistant bacteria. Notably, in filtration experiments for airborne bacteria, this double-grafted PET fiber demonstrated a high bacteria capture efficiency (95.68%) better than the untreated PET fiber (64.87%). Besides, the double-grafted PET fiber was capable of efficiently killing airborne bacteria. This work provides a new idea for the development of air filtration materials that can efficiently kill airborne pathogen and has good biosafety.

Potent antibacterial fibers with the functional “triad” of photothermal, silver, and Dex for bone infections

Bacteria-induced bone infections disrupt the healing and repair ability of bone tissue, posing a serious challenge to the treatment of clinical bone defects. In this study, novel composite fibers (PLLA/Dex/Ag fibers) with light-responsive rapid antibiosis and osteogenesis were obtained by mixing the photothermal agent silver nanoparticles (Ag-NPs) and the osteogenic drug dexamethasone (Dex) in polylactic acid (PLLA) using electrospinning, which can simultaneously kill multidrug-resistant bacteria and accelerate bone tissue healing due to the photothermal effect and release of Dex. Ag-NPs can act as antimicrobial agents released from the fibers and as photothermal agents to generate local high temperature and singlet state oxygen (1O2) under 808 nm light radiation, thereby killing the bacteria. The antimicrobial tests in vitro showed that PLLA/Dex/Ag fibers had an excellent antimicrobial effect on Escherichia coli and Staphylococcus aureus under NIR light radiation, shortening the effective antimicrobial time from 24 h to 6 h and achieving light-responsive antibiosis rapidly. Meanwhile, the released Dex could induce the differentiation of bone marrow mesenchymal stem cells into osteoblasts, thus promoting the healing of bone defects. In conclusion, this study provided a simple and effective strategy for the clinical treatment of bone infections.

Ultra-fast bacterial inactivation of Cu2O@halloysite nanotubes hybrids with charge adsorption and physical piercing ability for medical protective fabrics

• Rapid inactivation efficiency, security nano-Cu2O hybrid antibacterial material. • The effective antibacterial mechanism of Cu2O@HNTs. • Realization of high efficiency and broad-spectrum antibacterial protective fabric. Metals have been used for wound treatment and toxicity testing since ancient times. With the development of nanotechnology, metal oxides have been proven to have excellent sterilization and disinfection functions. However, the rapid bacterial inactivation efficiency and trapping physicochemical killing ability remain simultaneously undemonstrated in antibacterial nanohybrids. Here, we demonstrate a method for in-situ reduction of small-sized Cu 2 O particles on one-dimensional inorganic halloysite nanotubes (HNTs). The resultant Cu 2 O@HNTs hybrids not only give Cu 2 O excellent dispersibility, but also exert the synergistic effect of the charge adsorption of metal oxides and the physical piercing effect of the small-sized nanotubes. Furthermore, the release of Cu 2+ from hybrids damages cell membranes and denatures proteins and DNA. Through this sterilization mechanism, Cu 2 O@HNTs allow for the inactivation rate of Escherichia coli to reach 94.5% within 2 min and complete inactivation within 10 min. This excellent sterilization mode makes Cu 2 O@HNTs exhibit excellent broad-spectrum antibacterial activity and inactivation efficiency, while shows weak cytotoxicity. These hybrids were further applied in the processing of functional antibacterial fibers and fabrics. Thus, we believe that this excellent antibacterial hybrid is practically attractive in this critical time of the COVID-19 pandemic.

High metal-loaded Cu2O@TM hybrids for melt-spun antibacterial fibers engineered towards medical protective fabrics

Pathogens pose a serious threat to people's lives and health. Cuprous oxide (Cu2O) is widely used in the field of antibacterial fibers, but its large dosage and low loading limit its application. In this work, tourmaline (TM) was used as the inorganic carrier, and the surface treatment such as silanization and radiation carboxylation was carried out, which greatly improved the grafting rate of acrylic acid (AA) and made the Cu2O loading to 0.93 g/g. The prepared spherical Cu2O@TM has a series of antibacterial effects, such as electrostatic adsorption, destruction of cell membrane permeability, and release of reactive oxygen species. Therefore, Cu2O@TM can achieve 96.9% bacteriostatic rate in only 10 min at a concentration of 20 μg/mL, and completely inactivate Escherichia coli within 20 min. In addition, using only 0.4 wt% Cu2O@TM, the antibacterial rate of antibacterial fibers against Escherichia coli and Staphylococcus aureus were both above 99.99%.

Copper-thiosemicarbazone complexes conjugated-cellulose fibers: Biodegradable materials with antibacterial capacity

Personal protective equipment (PPE) is vital in battling bacteria crisis, but conventional PPE materials lack antimicrobial activities and environmental friendliness. Our work focused on developing biodegradable and antibacterial fibers as promising bioprotective materials. Here, we grafted highly effective antibacterial copper-thiosemicarbazone complexes (CT1–4) on cellulose fibers via covalent linkages. Multiple methods were used to characterize the chemical composition or morphology of CT1–4 conjugated-fibers. Conjugation of CT1–4 maintains the mechanical properties (Breaking strength: 2.35–2.45 cN/dtex, Breaking elongation: 7.19 %–7.42 %) and thermal stability of fibers. CT1 can endow cellulose fibers with the excellent growth inhibition towards Escherichia coli (E. coli) (GIR: 61.5 % ± 1.28 %), Staphylococcus aureus (S. aureus) (GIR: 85.7 % ± 1.93 %), and Bacillus subtilis (B. subtilis) (GIR: 87.6 % ± 1.44 %). We believe that the application of CT1 conjugated-cellulose fibers is not limited to the high-performance PPE, and also can be extended to various types of protective equipment for food and medicine safety.