Electrospun tetracycline hydrochloride loaded zein/gum tragacanth/poly lactic acid nanofibers for biomedical application

Zein-based nisin-loaded electrospun nanofibers as active packaging mats for control of Listeria monocytogenes on peach

Zein-based nanofibers (NFs) functionalized with nisin (NS), reinforced with montmorillonite nanoclay (nMMT) were fabricated by uniaxial electrospinning (ES) for the first time to preserve yellow peach. Spinnability/viscosity/conductivity optimizations generated porous (95.09%), bead-free, ultrathin (119 nm) NFs of low hydrophobicity (26.05°). Glutaraldehyde (GTA) crosslinking fostered positive outcomes of tensile strength (1.23 MPa), elongation (5.0%), hydrophobicity (99.46°), surface area (201.38 m2.g-1), pore size (2.88 nm), thermal stability (Tmax = 342 °C), antioxidant/cytotoxic activities in optimized NFs that released NS sustainably according to Korsmeyer-Peppas model indicating a Fickian diffusion mechanism with R2 = 0.9587. The novel NFs inhibited growth of Listeria monocytogenes/aerobic mesophilic populations in peach after 4 days of abusive storage, evincing their robustness in food contact applications. Simultaneously, quality parameters (moisture/texture/browning/total soluble solids/pH) and peach physical appearance were maintained for up to 8 days, endorsing the practical value of zein-based NFs as a non-thermal postharvest intervention for prolonging fruits storage life.

Tannic acid-reinforced soy protein/oxidized tragacanth gum-based multifunctional hemostatic film for regulation of wound healing

With recent advances in the field of tissue engineering, composite films with biocompatibility, antimicrobial properties, and wound healing properties have gained potential applications in the field of wound dressings. In this research work, composite films of soy protein (S)/oxidized tragacanth gum (G) were successfully made using the solution casting process. The metal-organic framework containing curcumin (MOF) with concentrations of 5 and 10 wt% and tannic acid (TA) with concentrations of 6 and 12 wt% were entered into the polymer film. Surface morphology with scanning electron microscope (FE-SEM), thermal stability, mechanical properties, chemical structure, antioxidant, water absorption, cell viability, antibacterial activity, and biodegradability of the prepared films were investigated in laboratory conditions. In addition, the toxicity of the films in the cell environment was investigated, and the results showed that cell growth and proliferation improved in the presence of the prepared films, especially films SG/MOF10/TA6 and SG/MOF10/TA12 due to the presence of TA and MOF containing curcumin. Also, the antibacterial activity of the films showed that the presence of tannic acid and curcumin in the structure of the films increases their ability against pathogens. According to the obtained results, the newly produced nanocomposite film (SG/MOF10/TA12) has a high potential to be used for wound dressing due to its favorable characteristics and was considered the optimal film.

Synthesis and in vitro evaluation of cross-linked tragacanthin nanofibers as implants for delivery of cisplatin to hepatocellular carcinoma

There is growing interest in the use of electrospun polymeric nanofibers in drug delivery systems due to their remarkable surface-to-volume ratio, which enhances the processes of drug loading, specific cell binding and proliferation. The preferred polymers for drug delivery must be biocompatible and biodegradable. Gum tragacanth is one of the materials of choice for drug delivery. This work aimed at cross-linking the tragacanthin, the water-soluble fraction of gum tragacanth, with glutaraldehyde, synthesis of the cross-linked nanofibers and evaluating their properties to encapsulate and deliver a drug using caffeine as a model drug in the first place. The nanofibers were then loaded with cisplatin and evaluated against HepG2 cell line. The drug-loaded nanofibers (dia. 0.841 μm) were prepared by electrospinning using glutaraldehyde as the cross-linker and glycerol as a plasticizer and characterized by scanning electron microscopy, Fourier transform-infrared spectroscopy, electronic spectroscopy, 1HNMR, powder X-ray diffraction analysis, and thermogravimetric analysis. They released the encapsulated drugs in a sustained manner at pH 7.4 over 4.5 days (∼275 h with ∼80 % release) following Higuchi (cisplatin) and Hixon-Crowell (caffeine) kinetics. In a cytotoxicity assay against HepG2 cell line the cisplatin-loaded nanofibers exhibited enhanced activity compared to that with the standard cisplatin and in the caspase activity assay it activated caspase 3 to a higher extent and 8 and 9 to double the extent (4-fold) of cisplatin, suggesting a higher apoptotic activity by the nanoformulation than the standard cisplatin. Thus, nanoformulation appeared to be a potential candidate for treating hepatocellular carcinoma as an implant.

Functional network copolymeric hydrogels derived from moringa gum: Physiochemical, drug delivery and biomedical properties

The article explores the synthesis of network hydrogels derived from moringa gum (MG) through a grafting reaction with poly (vinylsulfonic acid) and carbopol. These hydrogels are designed for use in drug delivery (DD) and wound hydrogels dressing (HYDR) applications. The copolymers were characterized by FESEM, EDX, AFM, FTIR, 13C NMR, XRD and DSC. Tetracycline release from hydrogel occurred gradually with a non-Fickian diffusion and was best described by the Hixson-Crowell kinetic model in artificial wound fluid. The HYDR demonstrated compatibility with blood, exhibited antioxidant properties and possessed tensile strength, in addition to their mucoadhesive characteristics. The copolymer dressings absorbed approximately 7 g of simulated fluid. The copolymers exhibited significant antioxidant activity, measuring at 84 % free radicals scavenging, during DPPH assay. These dressings demonstrated permeability to H2O and O2,. The hydrogel alone did not reveal antibacterial activities; however, when combined with antibiotic drug tetracycline, the dressings revealed notable antibacterial activities against Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli. The observed biomedical properties suggested that these hydrogels could serve as promising materials for drug delivery HYDR applications.

Development of nanofibrous scaffolds containing polylactic acid modified with turmeric and hydroxyapatite/vivianite nanoparticles for wound dressing applications

Damaging the outer layer of the body (the skin) has been a common issue for decades. Fabrication of nanofibrous membranes via the electrospinning technique for the sake of making the wound healing process more facile has caught a lot of interest. For this purpose, a polymeric scaffold of polylactic acid (PLA) was doped with nanoparticles with different concentrations of turmeric/hydroxyapatite/vivianite/graphene oxide. The obtained membrane was tested by XRD, SEM, FTIR, and XPS. The surface topography of the scaffold has experienced changes upon adding different concentrations of the nanoparticles. The contact angle was measured by water droplets. It accentuated change in CA starting from 43.9o for pure condition of PLA to 67.7o for PLA/turmeric/vivianite. The thermogravimetric analysis (TGA) test stated that the PLA scaffold features are thermally stable in relatively high-temperature conditions initiating from room temperature to about 300 °C, meeting the maximum loss in mass of about 5 %. The cell viability was carried out in prepared vitro for the sample which contains PLA/turmeric/vivianite/GO, it was elucidated that the IC50 was around 3060 μg/ml.

A novel designed nanofibrous mat based on hydroxypropyl methyl cellulose incorporating mango peel extract for potential use in wound care system

Skin tissue is damaged by factors such as burns, physical injuries and diseases namely diabetes. Infection and non-healing of burn wounds and lack of angiogenesis in diabetic wounds lead to extensive injuries and death. Therefore, the design of wound dressings with antibacterial and restorative capabilities is very important. In this study, nanofibers (NFs) including polyurethane (PU) and hydroxypropyl methyl cellulose (HPMC) were prepared with different ratios and Mango peel extract (MPE) loaded into NFs by electrospinning method. The morphology, chemical structure, porosity, degradation, water vapor permeability, mechanical properties, wettability, antioxidant activity and some cell studies and evaluation of their antibacterial properties were investigated. The optimal mat (PU90/HPMC10) had a defect-free morphology with homogeneous NFs. Furthermore, it showed improved biodegradability, water vapor permeability and porosity compared to other Mats. All NFs were non-toxic with hydrophilic behavior in the cellular environment and had acceptable hemocompatibility. The PU90/HPMC10/20 % optimal scaffold had significantly higher cell viability and proliferation than other samples and also had a higher antibacterial ability against pathogenic bacteria S. aureus (17 mm) and E. coli (11 mm). All these findings confirm that the produced NF mats, especially those loaded with MPE, have a high potential to be used as an effective wound dressing.

Herbal active ingredient-loaded poly(ω-pentadecalactone-co-δ-valerolactone)/gelatin nanofibrous membranes

Recently, there has been an accelerating interest in novel biocompatible wound dressings made of nano-sized materials, especially nanofibers. Electrospun nanofibers provide high surface area and mimic the extracellular matrix which enhances biocompatibility. Besides, nanofibrous structures have high active ingredient loading capacity as a result of their high surface-to-volume ratio and porosity. In the present study, curcumin-loaded poly(ω-pentadecalactone-co-δ-valerolactone)/gelatin (PDL-VL/Gel) nanofibrous membranes were fabricated to be used for healing skin wounds. Poly(ω-pentadecalactone-co-δ-valerolactone) copolymer has been enzymatically synthesized in previous studies, thus it improves the originality of the membrane. It was aimed to obtain a synergetic effect and increase the novelty of the work by blending synthetic and natural polymers. Moreover, it was preferred to provide antibacterial activity by the incorporation of a herbal ingredient (curcumin) as a natural alternative to commercial antibiotics. Varied amounts of curcumin (5-25 %, w:v) were electrospun together with PDL-VL/Gel (equal volume ratio) polymer blend (fiber diameters ranged between 554 and 1074 nm) and several characterizations (morphological and molecular structure, wettability characteristics, and thermal behavior) were applied to examine the curcumin incorporation. Afterwards, in vitro curcumin release studies were carried out and mathematical modeling was applied to release data to clarify the transport mechanism. Curcumin release profiles comprised of an initial burst release in the first hour followed by a sustained release through 24 h. Based on the antibacterial activity test results, 15 % curcumin loading ratio was found to be sufficient for the treatment of skin wounds infected by Gram-negative (E. coli) and Gram-positive (S. aureus and B. subtilis) bacteria. Additionally, nanofibrous membranes did not lead to cytotoxicity, and curcumin content further enhanced the viability of fibroblasts. Thus, the presented antibacterial nanofibrous membrane is suggested to be applied for the treatment of wound infections and accelerating the healing process.

The effect of κ-carrageenan and ursolic acid on the physicochemical properties of the electrospun nanofibrous mat for biomedical application

Wound dressing materials such as nanofiber (NF) mats have gained a lot of attention in recent years owing to their wonderful effect on accelerating the healing process and protection of wounds. In this regard, three different types of NF mats were fabricated using pure polyvinylpyrrolidone (PVP), PVP/κ-carrageenan (KG), and ursolic acid (UA) in the optimal PVP/KG ratio by electrospinning method to apply them as wound dressings. The morphology, chemical structure, degradation, porosity, mechanical properties and antioxidant activity of the produced NFs were investigated. Moreover, cell studies (e.g., cell proliferation, adhesion, and migration) and their antibacterial properties were evaluated. Adding KG and UA reduced the mean diameter size of the PVP-based NFs to ∼98 nm in the optimal sample, with defect-free morphology. The PVP/KG/UA 0.25 % exhibited the highest porosity, hydrophilicity, and degradation rate and a wound closure rate of 60 %, 2.5 times higher than that of the control group. Furthermore, this sample's proliferation and antibacterial ability were significantly higher than the other groups. These findings confirmed that the produced UA-loaded NFs have excellent properties as wound dressing.

Effect of tetracycline hydrochloride application on dental pulp stem cell metabolism-booster or obstacle for tissue engineering?

Introduction: Stem cells and scaffolds are an important foundation and starting point for tissue engineering. Human dental pulp stem cells (DPSC) are mesenchymal stem cells with self-renewal and multi-directional differentiation potential, and are ideal candidates for tissue engineering due to their excellent biological properties and accessibility without causing major trauma at the donor site. Tetracycline hydrochloride (TCH), a broad-spectrum antibiotic, has been widely used in recent years for the synthesis of cellular scaffolds to reduce the incidence of postoperative infections. Methods: In order to evaluate the effects of TCH on DPSC, the metabolism of DPSC in different concentrations of TCH environment was tested. Moreover, cell morphology, survival rates, proliferation rates, cell migration rates and differentiation abilities of DPSC at TCH concentrations of 0-500 μg/ml were measured. Phalloidin staining, live-dead staining, MTS assay, cell scratch assay and real-time PCR techniques were used to detect the changes in DPSC under varies TCH concentrations. Results: At TCH concentrations higher than 250 μg/ml, DPSC cells were sequestered, the proportion of dead cells increased, and the cell proliferation capacity and cell migration capacity decreased. The osteogenic and adipogenic differentiation abilities of DPSC, however, were already inhibited at TCH con-centrations higher than 50 μg/ml. Here, the expression of the osteogenic genes, runt-related transcription factor 2 (RUNX2) and osteocalcin (OCN), the lipogenic genes lipase (LPL), as well as the peroxisome proliferator-activated receptor-γ (PPAR-γ) expression were found to be down-regulated. Discussion: The results of the study indicated that TCH in concentrations above 50 µg/ml negatively affects the differentiation capability of DPSC. In addition, TCH at concentrations above 250 µg/ml adversely affects the growth status, percentage of living cells, proliferation and migration ability of cells.

Optimization and characterization of carrageenan/gelatin-based nanogel containing ginger essential oil enriched electrospun ethyl cellulose/casein nanofibers

This study aimed to evaluate the effects of nano-gels containing ginger essential oil (GEO) (NGs) made from gelatin and carrageenan gum on ethyl cellulose/casein nano-fibers (NFs). For this purpose, the mechanical, thermal, morphological, antibacterial, antioxidant, hemocompatibility, and biocompatibility properties of the NFs were assessed. It was observed that incorporating NGs into ethyl cellulose/casein NFs improved their morphology, porosity, mechanical properties, and thermal stability. Analysis of the SEM images revealed that adding NGs resulted in NFs with appropriate morphology, devoid of beads, and smaller diameters. The NFs containing NGs exhibited favorable antioxidant properties and inhibited the growth of Escherichia coli and Staphylococcus aureus. Cell viability studies demonstrated that none of the NFs were toxic to normal cells (Human umbilical vein endothelial cells (HUVEC)) and exhibited hemocompatibility. Considering these properties, ethyl cellulose/casein NFs containing NGs and GEO can be utilized as food packaging materials.

Investigation of the Real-Time Release of Doxycycline from PLA-Based Nanofibers

Electrospun mats of PLA and PLA/Hap nanofibers produced by electrospinning were loaded with doxycycline (Doxy) through physical adsorption from a solution with initial concentrations of 3 g/L, 7 g/L, and 12 g/L, respectively. The morphological characterization of the produced material was performed using scanning electron microscopy (SEM). The release profiles of Doxy were studied in situ using the differential pulse voltammetry (DPV) electrochemical method on a glassy carbon electrode (GCE) and validated through UV-VIS spectrophotometric measurements. The DPV method has been shown to be a simple, rapid, and advantageous analytical technique for real-time measurements, allowing accurate kinetics to be established. The kinetics of the release profiles were compared using model-dependent and model-independent analyses. The diffusion-controlled mechanism of Doxy release from both types of fibers was confirmed by a good fit to the Korsmeyer-Peppas model.

Agro-Industrial Plant Proteins in Electrospun Materials for Biomedical Application

Plant proteins are receiving a lot of attention due to their abundance in nature, customizable properties, biodegradability, biocompatibility, and bioactivity. As a result of global sustainability concerns, the availability of novel plant protein sources is rapidly growing, while the extensively studied ones are derived from byproducts of major agro-industrial crops. Owing to their beneficial properties, a significant effort is being made to investigate plant proteins' application in biomedicine, such as making fibrous materials for wound healing, controlled drug release, and tissue regeneration. Electrospinning technology is a versatile platform for creating nanofibrous materials fabricated from biopolymers that can be modified and functionalized for various purposes. This review focuses on recent advancements and promising directions for further research of an electrospun plant protein-based system. The article highlights examples of zein, soy, and wheat proteins to illustrate their electrospinning feasibility and biomedical potential. Similar assessments with proteins from less-represented plant sources, such as canola, pea, taro, and amaranth, are also described.

A review on tragacanth gum: A promising natural polysaccharide in drug delivery and cell therapy

Tragacanth is an abundant natural gum extracted from wounds created in some plants and is dried for use in various applications from industry to biomedicines. It is a cost-effective and easily accessible polysaccharide with desirable biocompatibility and biodegradability, drawing much attention for use in new biomedical applications such as wound healing and tissue engineering. Moreover, this anionic polysaccharide with a highly branched structure has been used as an emulsifier and thickening agent in pharmaceutical applications. In the following, this gum has been interested as an appealing biomaterial for producing engineering tools in drug delivery. Furthermore, the biological properties of tragacanth gum have made it a favorable biomaterial in cell therapies, especially for bone tissue engineering. This review aims to discuss the recent studies on this natural gum as a potential carrier for different drugs and cells.

A nanofiber-hydrogel composite from green synthesized AgNPs embedded to PEBAX/PVA hydrogel and PA/Pistacia atlantica gum nanofiber for wound dressing

A polyamide/Pistacia atlantica (P.a) gum nanofiber, fabricated by electrospinning method, was coated on a layer of PEBAX/PVA hydrogel embedded with green synthesized Ag nanoparticles (AgNPs) and the prepared nanofiber-hydrogel composite was assessed for wound dressing application. The AgNPs were characterized using ultraviolet-visible (UV-Vis), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), transmission electron microscopy (TEM), and Zeta potential analysis. The PEBAX/PVA/Ag hydrogel, prepared using solution casting method, displayed strong mechanical properties as Young's modulus and the elongation at break for the hydrogel containing AgNPs increased by 12 % and 96 %, respectively. The PEBAX/PVA/Ag hydrogel showed a high antimicrobial activity towards the E. coli (22.8 mm) with no cytotoxicity. The effect of adding the P.a gum on the properties of polyamide nanofiber was investigated using FTIR, SEM, and tensile tests. Samples were assessed by swelling, degradation, and water vapor transfer measurements. Very fine and continuous fibers with average diameters of ≤200 nm were observed by SEM analysis due to the addition of the P.a gum. The result of tensile test indicated that the addition of P.a gum improves the mechanical properties of nanofibers. The physical properties and biocompatibility of the two layers were shown to be complementary when combined.

Investigation of wound healing efficiency of multifunctional eudragit/soy protein isolate electrospun nanofiber incorporated with ZnO loaded halloysite nanotubes and allantoin

One significant aspect of the current therapeutic agents employed in wound healing involves the engineering of nano polymeric scaffolds to mimic the properties of extracellular matrix (ECM). The present work aimed to prepare and evaluate Eudragit® L100 (EU) nanofibers in combination with soy protein isolate (SPI). Allantoin (Ala) with a 2 wt% was encapsulated as a model drug renowned for its anti-inflammatory and antioxidant agents. Moreover, the synthesized ZnO-halloysite nanotubes (ZHNTs) with different concentrations of 1, 3, and 5 wt% were incorporated into the EU/SPI/Ala nanofiber as a reinforcing filler and a remarkable antibacterial agent. The scanning electron microscope (SEM) analysis showed that by increasing the weight percentage of SPI from 1 % to 2.5 %, the average diameter of nanofibers decreased from 132.3 ± 51.3 nm to 126.7 ± 47.2 nm. It was 223.5 ± 95.6 nm for nanofibers containing 5 wt% ZHNTs (the optimal sample). The evaluation of in vitro release kinetics of Ala for 24 h, showed a burst release during the first 2 h and a sustained release during the subsequent times. Moreover, the structure, crystallinity, and thermal stability of synthesized nanofibers were characterized by Fourier Transform Infrared Spectrometry (FTIR), X-ray diffraction (XRD), and Thermo gravimetric analysis (TGA), respectively. In vitro degradation and mechanical characteristics of these nanofibers were studied. Furthermore, the capability of the nanofibers for cell proliferation was revealed through the MTT test and field emission scanning electron microscopy (FESEM) images of cell attachment. The antimicrobial activity of EU/SPI/Ala/ZHNTs showed that this sample with high ZHNTs content (5 w%t) had the most remarkable antibacterial activity against S. aureus. The results revealed that EU/SPI/Ala/ZHNTs mats could be promising potential wound dressings.

The potential of a natural iron ore residue application in the efficient removal of tetracycline hydrochloride from an aqueous solution: insight into the degradation mechanism

In the existing research, most of the heterogeneous catalysts applied in the activation of persulfate to degrade organic pollutants were synthesized from chemical reagents in the laboratory. In this paper, we have obtained a spent iron ore (IO) residue directly collecting from the iron ore plants, and efficiently activating peroxydisulfate (PS) to produce reactive free radicals. The experimental results demonstrated that the IO could effectively activate PS to degrade tetracycline hydrochloride (TCH), with TCH removal rate reaching up to 85.6% within 2 h at room temperature. The TCH removal rate was increased with increasing iron ore dosage, while the more acidic pH condition would be favorable to TCH removal process. The material characterization results demonstrated that the dominant components of IO were Fe₃O₄ and FeOOH. The transformation from Fe(II) to Fe(III) at the surface IO was observed after TCH degradation. What's more, the quenching experiment and EPR detection results confirmed that the sulfate radical (SO₄^•-) and hydroxyl radicals (•OH) would be acting as the main free radicals for TCH degradation. This study could not only explore a novel way to recycle the discarded iron ore, but also further expand its application in an effective activation of PS in an aqueous solution.

Optimization and characterization of a novel tea tree oil-integrated poly (ε-caprolactone)/soy protein isolate electrospun mat as a wound care system

A set of poly (ε-caprolactone)/soy protein isolate (PCL/SPI) mats with different ratios of PCL to SPI was fabricated using the electrospinning method. The mat with PCL to SPI ratio of 95:5 (PS 95:5) had the narrowest nanofibers, the highest percentage of porosity, the lowest swelling ratio, the least vapor transmission, and the slowest degradation rate among the prepared mats. The hemolysis assay indicated that all mats can be considered biocompatible biomaterials. In continue, three different weight ratios of tea tree oil (TTO) were loaded into the PS 95:5 mat. The release profiles illustrated that higher amounts of TTO could be released in an acidic environment. The antioxidant activity of the mats increased by the increase in their TTO content. The cell viability test, cell adhesion images, and live/dead assay of TTO-loaded mats affirmed that all fabricated mats were biocompatible. The scratch wound assay expressed that TTO accelerates the rate of wound closure. The TTO-loaded mats illustrated antibacterial activity against both Escherichia coli and Staphylococcus aureus bacteria. The obtained outcomes revealed that TTO-loaded PCL/SPI mats can be considered promising potential wound dressings.

Recent Advances in Designing Fibrous Biomaterials for the Domain of Biomedical, Clinical, and Environmental Applications

Unique properties and potential applications of nanofibers have emerged as innovative approaches and opportunities in the biomedical, healthcare, environmental, and biosensor fields. Electrospinning and centrifugal spinning strategies have gained considerable attention among all kinds of strategies to produce nanofibers. These techniques produce nanofibers with high porosity and surface area, adequate pore architecture, and diverse chemical compositions. The extraordinary characteristics of nanofibers have unveiled new gates in nanomedicine to establish innovative fiber-based formulations for biomedical use, healthcare, and a wide range of other applications. The present review aims to provide a comprehensive overview of nanofibers and their broad range of applications, including drug delivery, biomedical scaffolds, tissue/bone-tissue engineering, dental applications, and environmental remediation in a single place. The review begins with a brief introduction followed by potential applications of nanofibers. Finally, the future perspectives and current challenges of nanofibers are demonstrated. This review will help researchers to engineer more efficient multifunctional nanofibers with improved characteristics for their effective use in broad areas. We strongly believe this review is a reader's delight and will help in dealing with the fundamental principles and applications of nanofiber-based scaffolds. This review will assist students and a broad range of scientific communities to understand the significance of nanofibers in several domains of nanotechnology, nanomedicine, biotechnology, and environmental remediation, which will set a benchmark for further research.

Efficient Adsorption-Photocatalytic Removal of Tetracycline Hydrochloride over Octahedral MnS

To disclose the effect of crystal plane on the adsorption-photocatalytic activity of MnS, octahedral MnS was prepared via the hydrothermal route to enhance the adsorption and photocatalytic efficiencies of tetracycline hydrochloride (TCH) in visible light region. The optimal MnS treated at 433 K for 16 h could remove 94.83% TCH solution of 260 mg L-1 within 180 min, and its adsorption-photocatalytic efficiency declined to 89.68% after five cycles. Its excellent adsorption-photocatalytic activity and durability were ascribed to the sufficient vacant sites of octahedral structure for TCH adsorption and the feasible band-gap structure for visible-light response. In addition, the band gap structure (1.37 eV) of MnS with a conduction band value of -0.58 eV and a valence band value of 0.79 eV was favorable for the generation of O2-, while unsuitable for the formation of OH. Hence, octahedral MnS was a potential material for the removal of antibiotics from wastewater.

Honey-Loaded Reinforced Film Based on Bacterial Nanocellulose/Gelatin/Guar Gum as an Effective Antibacterial Wound Dressing

Recently, the use of bacterial nanocellulose (BNC) produced by Acetobacter, which has suitable properties for tissue engineering application as a perfect wound dressing, has attracted considerable attention. For this purpose, we successfully developed honey loaded BNC-reinforced gelatin/dialdehyde-modified guar gum films (H/BNC/Ge/D-GG). Prepared films were studied for their morphological, thermal stability, mechanical, water solubility and degradability properties. The physicochemical properties of the developed films with or without honey loading were studied. The results indicated that by enhancing the honey content of the film, the degradation behavior, adhesion and proliferation of NIH-3T3 fibroblast cells were improved. The films with 15 wt% of honey revealed inhibition activity against S. aureus (13.0±0.1 mm) and E. coli (15.0±1.0 mm) bacteria. Cell culture results demonstrated that the prepared films had good cytocompatibility. Based on the results, the prepared H/BNC/Ge/D-GG films appear to have high potential for antibacterial wound dressings.

Zein-polycaprolactone core-shell nanofibers for wound healing

In a previous study, we developed electrospun antimicrobial microfiber scaffolds for wound healing composed of a core of zein protein and a shell containing polyethylene oxide. While providing a promising platform for composite nanofiber design, the scaffolds showed low tensile strengths, insufficient water stability, as well as burst release of the antimicrobial drug tetracycline hydrochloride, properties which are not ideal for the use of the scaffolds as wound dressings. Therefore, the aim of the present study was to develop fibers with enhanced mechanical strength and water stability, also displaying sustained release of tetracycline hydrochloride. Zein was chosen as core material, while the shell was formed by the hydrophobic polymer polycaprolactone, either alone or in combination with polyethylene oxide. As compared to control fibers of pristine polycaprolactone, the zein-polycaprolactone fibers exhibited a reduced diameter and hydrophobicity, which is beneficial for cell attachment and wound closure. Such fibers also demonstrated sustained release of tetracycline hydrochloride, as well as water stability, ductility, high mechanical strength and fibroblast attachment, hence representing a step towards the development of biodegradable wound dressings with prolonged drug release, which can be left on the wound for a longer time.

An Overview on the Recent Advances in the Treatment of Infected Wounds: Antibacterial Wound Dressings

A wound can be surgical, cuts from an operation or due to accident and trauma. The infected wound, as a result of bacteria growth within the damaged skin, interrupts the natural wound healing process and significantly impacts the quality of life. Wound dressing is an important segment of the skincare industry with its economic burden estimated at $ 20.4 billion (in 2021) in the global market. The results of recent clinical trials suggest that the use of modern dressings can be the easiest, most accessible, and most cost-effective way to treat chronic wounds and, hence, holds significant promise. With the sheer number of dressings in the market, the selection of correct dressing is confusing for clinicians and healthcare workers. The aim of this research was to review widely used types of antibacterial wound dressings, as well as emerging products, for their efficiency and mode of action. In this review, we focus on introducing antibiotics and antibacterial nanoparticles as two important and clinically widely used categories of antibacterial agents. The perspectives and challenges for paving the way for future research in this field are also discussed. This article is protected by copyright. All rights reserved.

Protein-Based Systems for Topical Antibacterial Therapy

Recently, proteins are gaining attention as potential materials for antibacterial therapy. Proteins possess beneficial properties such as biocompatibility, biodegradability, low immunogenic response, ability to control drug release, and can act as protein-mimics in wound healing. Different plant- and animal-derived proteins can be developed into formulations (films, hydrogels, scaffolds, mats) for topical antibacterial therapy. The application areas for topical antibacterial therapy can be wide including bacterial infections in the skin (e.g., acne, wounds), eyelids, mouth, lips, etc. One of the major challenges of the healthcare system is chronic wound infections. Conventional treatment strategies for topical antibacterial therapy of infected wounds are inadequate, and the development of newer and optimized formulations is warranted. Therefore, this review focuses on recent advances in protein-based systems for topical antibacterial therapy in infected wounds. The opportunities and challenges of such protein-based systems along with their future prospects are discussed.

Electrospun poly(ω-pentadecalactone-co-ε-caprolactone)/gelatin/chitosan ternary nanofibers with antibacterial activity for treatment of skin infections

In recent years, there is an increasing attention on biocompatible electrospun nanofibers for drug delivery applications since they provide high surface area, controlled and sustained drug release, and they mimic the extracellular matrix. In the present study, tetracycline hydrochloride (TCH) antibiotic loaded poly(ω-pentadecalactone-co-ε-caprolactone)/gelatin/chitosan nanofibrous membranes were fabricated as a controlled drug delivery system. Poly(ω-pentadecalactone-co-ε-caprolactone) copolymer has been enzymatically synthesized in previous studies, thus it provides an originality to the membrane. Combination of a synthetic polymer, a protein, and a polysaccharide in order to obtain a synergetic effect is another novelty of this work and there exists limited examples for such electrospun membrane. Varied amounts of TCH was electrospun together with poly(ω-pentadecalactone-co-ε-caprolactone)/gelatin/chitosan (50/40/10 vol ratio) polymer blend (fiber diameters ranged between 85.7-225.2 nm) and several characterizations (morphological and molecular structure, wettability characteristics, and thermal behavior) were applied to examine the drug incorporation. Subsequently, in vitro drug release studies were conducted and mathematical modeling was applied for the detection of transport mechanism of drug. TCH release proceeded 14 days through an initial burst release in first hour and followed by a sustained release. 1% TCH-loaded sample was shown as optimal preparation with 96.5% total drug release and 11.8% initial burst release. TCH-loaded preparations demonstrated a good antibacterial activity against Gram-positive (Staphylococcus aureus and Bacillus subtilis) bacteria and a limited effect (no inhibition zone observed below 3% TCH concentration) against Gram-negative (Escherichia coli) bacterium. Thus, TCH concentrations of ≥ 3% could be preferred to obtain a wide-spectrum effectiveness. The presented drug delivery system is suggested to be applied for treatment of skin infections as a wound dressing device.

A novel multifunctional bilayer scaffold based on chitosan nanofiber/alginate-gelatin methacrylate hydrogel for full-thickness wound healing

Due to their lack of multifunctionality, the majority of traditional wound dressings do not support all the clinical requirements. Bilayer wound dressings with multifunctional properties can be attractive for effective skin regeneration. In the present study, we designed a multifunctional bilayer scaffold containing Chitosan-Polycaprolactone (PC) nanofiber and tannic acid (TA) reinforced methacrylate gelatin (GM)/alginate (Al) hydrogel (GM/Al/TA). PC nanofibers were coated with GM/Al/TA hydrogel to obtain a bilayer nanocomposite scaffold (Bi-TA). The GM/Al/TA hydrogel layer of Bi-TA showed antibacterial, free radical scavenging, and biocompatibility properties. Also, PC nanofiber acted as a barrier for preventing bacterial invasion and moisture loss of the hydrogel layer. The wound healing performance of the Bi-TA scaffold was investigated via a full-thickness wound model. In addition, the histopathological and immunohistochemical (IHC) stainings of transforming growth factor-β1(TGF-β1) and tumor necrosis factor-α (TNF-α) were assessed. The results indicated an enhanced wound closure rate, effective collagen deposition, quick re-epithelialization, more skin appendages, and replacement of defect area with normal skin tissue by Bi-TA scaffold compared to other groups. Additionally, the regulation of TGF-β1 and TNF-α was observed by Bi-TA dressing. Overall, the Bi-TA with appropriate structural and multifunctional properties can be an excellent candidate for developing effective dressings for wound healing applications.

Antibacterial nanofibers of pullulan/tetracycline-cyclodextrin inclusion complexes for Fast-Disintegrating oral drug delivery

Tetracycline is a widely used antibiotic suffering from poor water solubility and low bioavailability. Here, hydroxypropyl-beta-cyclodextrin (HPβCD) was used to form inclusion complexes (IC) of tetracycline with 2:1 M ratio (CD:drug). Then, tetracycline-HPβCD-IC was mixed with pullulan- a non-toxic, water-soluble biopolymer - to form nanofibrous webs via electrospinning. The electrospinning of pullulan/tetracycline-HPβCD-IC was yielded into defect-free nanofibers collected in the form of a self-standing and flexible material with the loading capacity of ∼ 7.7 % (w/w). Pullulan/tetracycline nanofibers was also generated as control sample having the same drug loading. Tetracycline was found in the amorphous state in case of pullulan/tetracycline-HPβCD nanofibers due to inclusion complexation. Through inclusion complexation with HPβCD, enhanced aqueous solubility and faster release profile were provided for pullulan/tetracycline-HPβCD-IC nanofibers compared to pullulan/tetracycline one. Additionally, pullulan/tetracycline-HPβCD-IC nanofibers readily disintegrated when wetted with artificial saliva while pullulan/tetracycline nanofibers were not completely absorbed by the same simulate environment. Electrospun nanofibers showed promising antibacterial activity against both gram-positive and gram-negative bacteria. Briefly, our findings indicated that pullulan/tetracycline-HPβCD-IC nanofibers could be an attractive material as orally fast disintegrating drug delivery system for the desired antibiotic treatment thanks to its promising physicochemical and antibacterial properties.

Bovine Serum Albumin-Coated Niclosamide-Zein Nanoparticles as Potential Injectable Medicine against COVID-19

(1) Background: COVID-19 has affected millions of people worldwide, but countries with high experimental anti-SARS-CoV-2 vaccination rates among the general population respectively show progress in achieving general herd immunity in the population (a combination of natural and vaccine-induced acquired immunity), resulting in a significant reduction in both newly detected infections and mortality rates. However, the longevity of the vaccines’ ability to provide protection against the ongoing pandemic is still unclear. Therefore, it is of utmost importance to have new medications to fight against the pandemic at the earliest point possible. Recently, it has been found that repurposing already existing drugs could, in fact, be an ideal strategy to formulate effective medication for COVID-19. Though there are many FDA-approved drugs, it has been found that niclosamide (NIC), an anthelmintic drug, has significantly high potential against the SARS-CoV-2 virus. (2) Methods: Here we deployed a simple self-assembling technique through which Zein nanoparticles were successfully used to encapsulate NIC, which was then coated with bovine serum albumin (BSA) in order to improve the drugs’ stability, injectablity, and selectivity towards the virus-infected cells. (3) Results: The particle size for the BSA-stabilized Zein-NIC nanohybrid was found to be less than 200 nm, with excellent colloidal stability and sustained drug release properties. In addition, the nanohybrid showed enhanced drug release behavior under serum conditions, indicating that such a hybrid drug delivery system could be highly beneficial for treating COVID-19 patients suffering from high endothelial glycocalyx damage followed by a cytokine storm related to the severe inflammations.

Propolis loaded and genipin-crosslinked PVA/chitosan membranes; characterization properties and cytocompatibility/genotoxicity response for wound dressing applications

Loading propolis by a simple process using genipin as a crosslinking agent and fabrication of a novel PVA/Chitosan-Propolis membrane scaffolds were reported for wound dressing applications. The research is focused on the effects of propolis on characterization properties of membrane such as chemical structure, surface morphology, degradation ratio, crystallinity, hydrophilicity, water uptake capacity, water vapour transmission rate and mechanical aspect. It was noticed that water uptake capacity and hydrophilicity properties of membrane considerably affected by the propolis. By addition of (0.50, % v/v) propolis, the contact angle of the PVA/Chitosan membrane was remarkably decreased from 86.29° ± 3 to 45 ± 2°. 3-(4,5-dimethylthiazoyl-2-yl)-2,5-diphenylte-trazolium (MTT) bromide test and SEM were used to analyse the cytocompatibility of the membranes and morphology of cells on membrane. The propolis incorporated membrane showed cell proliferation rate 176 ± 13%, 775 ± 1%, and 853 ± 23%, at 24 h, 27 h and 120 h, respectively. SEM images also supported the cell behaviour on membrane. DNA fragmentation was also investigated with genotoxicity test. The studies on the interactions between membranes and MEF cells revealed that the incorporation of propolis into membrane promoted cell proliferation. These overall results presented that propolis incorporated membranes could have potentially appealing application as scaffolds for wound healing applications.

Prevention of urinary infection through the incorporation of silver-ricinoleic acid-polystyrene nanoparticles on the catheter surface

Nosocominal infections associated with biofilm formation on urinary catheters cause serious complications. The aim of this study was to investigate the feasibility of the polyurethane (PU) catheter modified with tetracycline hydrochloride (TCH) attached Ag nanoparticles embedded PolyRicinoleic acid-Polystyrene Nanoparticles (PU-TCH-AgNPs-PRici-PS NPs) and the influence on antimicrobial and antibiofilm activity of urinary catheters infected by Escherichia coli and Staphylococcus aureus. For this purpose, AgNPs embedded PRici graft PS graft copolymers (AgNPs-PRici-g-PS) were synthesized via free radical polymerization and characterized by FTIR, HNMR and DSC. AgNPs-PRici-PS NPs were prepared and optimized by the different parameters and the optimized size of nanoparticle was found as about 150 ± 1 nm. The characterization of the nanoparticles and the morphological evaluation were carried out by FTIR and SEM. Short term stability of nanoparticles was realised at 4°C for 30 days. In vitro release profiles of TCH and Ag NPs were also investigated. The formation of biofilm on PU modified TCH-Ag NPs-PRici-PS NPs, was evaluated and the biocompatibility test of the nanoparticles was realized via the mouse fibroblast (L929) and mouse urinary bladder cells (G/G An1). This is the first time that TCH-AgNPs-PRici-PS NPs used in the modification of PU catheter demonstrated high antimicrobial and antibiofilm activities against the urinary tract infection.

Development of a novel reinforced film based on gellan gum/cellulose nanofiber/soy protein for skin tissue engineering application

Recently, the importance of using biocompatible nanocomposite film with suitable properties has attracted interest for use in potential applications in the biomedical area.

Electrospinning Proteins for Wound Healing Purposes: Opportunities and Challenges

With the growth of the aging population worldwide, chronic wounds represent an increasing burden to healthcare systems. Wound healing is complex and not only affected by the patient's physiological conditions, but also by bacterial infections and inflammation, which delay wound closure and re-epithelialization. In recent years, there has been a growing interest for electrospun polymeric wound dressings with fiber diameters in the nano- and micrometer range. Such wound dressings display a number of properties, which support and accelerate wound healing. For instance, they provide physical and mechanical protection, exhibit a high surface area, allow gas exchange, are cytocompatible and biodegradable, resemble the structure of the native extracellular matrix, and deliver antibacterial agents locally into the wound. This review paper gives an overview on cytocompatible and biodegradable fibrous wound dressings obtained by electrospinning proteins and peptides of animal and plant origin in recent years. Focus is placed on the requirements for the fabrication of such drug delivery systems by electrospinning as well as their wound healing properties and therapeutic potential. Moreover, the incorporation of antimicrobial agents into the fibers or their attachment onto the fiber surface as well as their antimicrobial activity are discussed.