Preparation and characterization of electrospun alginate nanofibers loaded with ciprofloxacin hydrochloride

Polysaccharide base electrospun nanofibrous scaffolds for cartilage tissue engineering: Challenges and opportunities

Polysaccharides, known as naturally abundant macromolecular materials which can be easily modified chemically, have always attracted scientists' interest due to their outstanding properties in tissue engineering. Moreover, their intrinsic similarity to cartilage ECM components, biocompatibility, and non-harsh processing conditions make polysaccharides an excellent option for cartilage tissue engineering. Imitating the natural ECM structure to form a fibrous scaffold at the nanometer scale in order to recreate the optimal environment for cartilage regeneration has always been attractive for researchers in the past few years. However, there are some challenges for polysaccharides electrospun nanofibers preparation, such as poor solubility (Alginate, cellulose, chitin), high viscosity (alginate, chitosan, and Hyaluronic acid), high surface tension, etc. Several methods are reported in the literature for facing polysaccharide electrospinning issues, such as using carrier polymers, modification of polysaccharides, and using different solvent systems. In this review, considering the importance of polysaccharide-based electrospun nanofibers in cartilage tissue engineering applications, the main achievements in the past few years, and challenges for their electrospinning process are discussed. After careful investigation of reported studies in the last few years, alginate, chitosan, hyaluronic acid, chondroitin sulfate, and cellulose were chosen as the main polysaccharide base electrospun nanofibers used for cartilage regeneration.

Heat-treated alginate-polycaprolactone core-shell nanofibers by emulsion electrospinning process for biomedical applications

Fabrication of Core-shell nanofibrous mat which is a promising tool for a wide range of applications in tissue engineering can be developed using water in oil (W/O) or oil in water (O/W) emulsion electrospinning. In this study, for the first time, we fabricated an O/W emulsion-based electrospun core-shell mat using polycaprolactone (PCL) as a core and the blend solution of alginate (Alg) and polyethylene oxide (PEO) as shell material. To achieve a stable core-shell mat, firstly, Alg was modified with heat treatment to decrease the molecular weight of Alg. Then, to improve the chain flexibility of Alg, PEO as a second polymer was added to facilitate its electrospinnability. The different volume ratios of O/W were then fabricated by adding PCL to the Alg-PEO solution to find an optimized emulsion solution. The morphology, swelling, and porosity of the construct were evaluated. At the same time, the mechanical characteristic of fibers was evaluated in both dry and wet conditions. This study also examined cell-scaffold interactions to address the need for a scaffolding material to be suitable for tissue engineering and biomedical applications. Finally, the result exhibited a distinct core-shell structure with better mechanical properties compared to the Alg-PEO.

Functionally multifaceted alginate/curdlan/agarose-based bilayer fibro-porous dressings for addressing full-thickness diabetic wounds

Full-thickness diabetic wounds are chronic injuries characterized by bleeding, excessive exude, and prolonged inflammation. Single-layer dressings fail to address their disturbed pathophysiology. Therefore, bilayer dressings with structural and compositional differences in each layer have gained attention. We hypothesized that natural polymer (alginate, curdlan, and agarose) based bilayer dressings with inherent healing properties could effectively resolve these issues. Hence, bilayer dressings were fabricated by electrospinning curdlan/agarose/ polyvinyl alcohol blend (top layer) on an alginate/agarose/polyvinyl alcohol-based lyophilized porous (bottom) layer. Ciprofloxacin was incorporated in both layers as a potential antibacterial drug. The bilayer dressing exhibited high swelling (~1300 %), biocompatibility (>90 % with NIH 3T3 and L929 mouse fibroblasts), and hemocompatibility (hemolysis <5 %). In vitro, scratch assay revealed a faster wound closure (~ 95-100 %) than control. Inhibition zone assay revealed antibacterial activity against Staphylococcus aureus and Escherichia coli. Real-time (in vitro) gene expression experiments performed using human THP-1 macrophages exhibited a significant increase in anti-inflammatory cytokines (4.51 fold in IL-10) and a decrease in pro-inflammatory cytokines (1.42 fold in IL-6) in comparison to lipopolysaccharide. Thus, fabricated dressings with high swelling, hemostatic, immunomodulatory, and antibacterial characteristics can serve as potential multifunctional and sustainable templates for healing full-thickness diabetic wounds.

Functional electrospun nanofibers: fabrication, properties, and applications in wound-healing process

Electrostatic spinning as a technique for producing nanoscale fibers has recently attracted increasing attention due to its simplicity, versatility, and loadability. Nanofibers prepared by electrostatic spinning have been widely studied, especially in biomedical applications, because of their high specific surface area, high porosity, easy size control, and easy surface functionalization. Wound healing is a highly complex and dynamic process that is a crucial step in the body's healing process to recover from tissue injury or other forms of damage. Single-component nanofibers are more or less limited in terms of structural properties and do not fully satisfy various needs of the materials. This review aims to provide an in-depth analysis of the literature on the use of electrostatically spun nanofibers to promote wound healing, to overview the infinite possibilities for researchers to tap into their biomedical applications through functional composite modification of nanofibers for advanced and multifunctional materials, and to propose directions and perspectives for future research.

Marine-derived polysaccharides and their therapeutic potential in wound healing application - A review

Polysaccharides originating from marine sources have been studied as potential material for use in wound dressings because of their desirable characteristics of biocompatibility, biodegradability, and low toxicity. Marine-derived polysaccharides used as wound dressing, provide several benefits such as promoting wound healing by providing a moist environment that facilitates cell migration and proliferation. They can also act as a barrier against external contaminants and provide a protective layer to prevent further damage to the wound. Research studies have shown that marine-derived polysaccharides can be used to develop different types of wound dressings such as hydrogels, films, and fibres. These dressings can be personalised to meet specific requirements based on the type and severity of the wound. For instance, hydrogels can be used for deep wounds to provide a moist environment, while films can be used for superficial wounds to provide a protective barrier. Additionally, these polysaccharides can be modified to improve their properties, such as enhancing their mechanical strength or increasing their ability to release bioactive molecules that can promote wound healing. Overall, marine-derived polysaccharides show great promise for developing effective and safe wound dressings for various wound types.

Multifunctional Electrospun Nanofibers for Biosensing and Biomedical Engineering Applications

Nanotechnology is experiencing unprecedented developments, leading to the advancement of functional nanomaterials. The properties that stand out include remarkable porosity, high-specific surface area, excellent loading capacity, easy modification, and low cost make electrospun nanofibers. In the biomedical field, especially in biosensors, they exhibit amazing potential. This review introduces the principle of electrospinning, describes several structures and biomaterials of electrospun nanofibers used for biomedicine, and summarizes the applications of this technology in biosensors and other biomedical applications. In addition, the technical challenges and limitations of electrospinning for biomedicine are discussed; however, more research work is needed to elucidate its full potential.

Fucoidan- and Ciprofloxacin-Doped Plasma-Activated Polymer Coatings on Biodegradable Zinc: Hemocompatibility and Drug Release

Blood-contacting medical devices such as biodegradable metallic bone implant materials are expected to show excellent hemocompatibility both in vitro and in vivo. Different approaches are being studied and used to modify biomaterial surfaces for enhanced biocompatibility and hemocompatibility. However, the composition of degradable biomaterial must address several drawbacks at once. Iron-reinforced zinc material was used as a metallic substrate with improved mechanical properties when compared with those of pure zinc. Poly(lactic) acid (PLA) or polyethylenimine (PEI) was selected as a polymeric matrix for further doping with antibiotic ciprofloxacin (CPR) and marine-sourced polysaccharide fucoidan (FU), which are known for their antibacterial and potential anticoagulant properties, respectively. Radiofrequency air plasma was employed to induce metallic/polymer-coated surface activation before further modification with FU/CPR. Sample surface morphology and composition were studied and evaluated (contact angle measurements, AFM, SEM, and FT-IR) along with the hemolysis ratio and platelet adhesion test. Successful doping of the polymer layer by FU/CRP was confirmed. While PEI induced severe hemolysis over 12%, the PLA-coated samples exhibited even lower hemolysis (∼2%) than uncoated samples while the uncoated samples showed the lowest platelet adhesion. Moreover, gradual antibiotic release from PLA determined by the electrochemical methods using screen-printed carbon electrodes was observed after 24, 48, and 72 h, making the PLA-coated zinc-based material an attractive candidate for biodegradable material design.

Chitosan/poly (3-hydroxy butyric acid-co-3-hydroxy valeric acid) electrospun nanofibers with cephradine for superficial incisional skin wound infection management

The belated and compromised incisional skin wound healing caused by the invading of methicillin-resistance staphylococcus aureus is a serious problem in clinic. Designing a new therapeutic strategy to inhibit the growth of invading bacteria at post-surgical site might be helpful in fast healing of post-surgical wounds. In this study, we developed cephradine (Ceph) encapsulated chitosan and poly (3-hydroxy butyric acid-co-3-hydroxy valeric acid, (PHBV)) hybrid nanofibers (Ceph-CHP NFs) employing an electrospinning method to revamp the Ceph bioavailability at the post-surgical wound site to prevent the growth of invading bacteria and trigger the wound healing process. The fabricated nanofibers revealed smooth and uniform surface with a diameter range of 160 ± 25 to 190 ± 55 nm, depending on Ceph concentration. Further, the electrospun hybrid nanofibers exhibited a higher entrapment efficiency (EE) and drug loading capacity (DLC) nearly 72.8 ± 5.2 % and 16.5 ± 3.2 %, respectively. Moreover, the Ceph-CHP NFs showed high swelling rate and biodegradation in presence of lysozyme in contrast to blank CHP NFs. Ceph-CHP NFs exhibited fast drug release in initial few hours followed by slow and controlled drug release drug up to 48 h with a constant rate. In-vitro antimicrobial studies indicated the heightened efficacy of Ceph-CHP NFs against MRSA clinical isolates and exhibited no visible cytotoxicity against keratinocytes, HC11 and L929 cells. Lastly, Ceph-CHP NFs showed the enhanced wound healing and bacterial clearance from post-surgical wound compared to Ceph in C57BL/6 mice skin model. Overall, our results showed that Ceph-CHP NFs might be used as a promising wound dressing material for MRSA-infected post-surgical wounds.

Recent Advances in Functional Wound Dressings

Significance: Nowadays, the wound dressing is no longer limited to its primary wound protection ability. Hydrogel, sponge-like material, three dimensional-printed mesh, and nanofiber-based dressings with incorporation of functional components, such as nanomaterials, growth factors, enzymes, antimicrobial agents, and electronics, are able to not only prevent/treat infection but also accelerate the wound healing and monitor the wound-healing status. Recent Advances: The advances in nanotechnologies and materials science have paved the way to incorporate various functional components into the dressings, which can facilitate wound healing and monitor different biological parameters in the wound area. In this review, we mainly focus on the discussion of recently developed functional wound dressings. Critical Issues: Understanding the structure and composition of wound dressings is important to correlate their functions with the outcome of wound management. Future Directions: "All-in-one" dressings that integrate multiple functions (e.g., monitoring, antimicrobial, pain relief, immune modulation, and regeneration) could be effective for wound repair and regeneration.

Exploring the Impact of Alginate-PVA Ratio and the Addition of Bioactive Substances on the Performance of Hybrid Hydrogel Membranes as Potential Wound Dressings

Healthcare professionals face an ongoing challenge in managing both acute and chronic wounds, given the potential impact on patients' quality of life and the limited availability of expensive treatment options. Hydrogel wound dressings offer a promising solution for effective wound care due to their affordability, ease of use, and ability to incorporate bioactive substances that enhance the wound healing process. Our study aimed to develop and evaluate hybrid hydrogel membranes enriched with bioactive components such as collagen and hyaluronic acid. We utilized both natural and synthetic polymers and employed a scalable, non-toxic, and environmentally friendly production process. We conducted extensive testing, including an in vitro assessment of moisture content, moisture uptake, swelling rate, gel fraction, biodegradation, water vapor transmission rate, protein denaturation, and protein adsorption. We evaluated the biocompatibility of the hydrogel membranes through cellular assays and performed instrumental tests using scanning electron microscopy and rheological analysis. Our findings demonstrate that the biohybrid hydrogel membranes exhibit cumulative properties with a favorable swelling ratio, optimal permeation properties, and good biocompatibility, all achieved with minimal concentrations of bioactive agents.

Organomodified nanoclay with boron compounds is improving structural and antibacterial properties of nanofibrous matrices

In this study, nanofibrous polymeric matrices were successfully developed with nanoclay, montmorillonite (MMT) and various boron (B) compounds, which were known to have positive effects on the wound healing with elevated antibacterial properties. For this purpose, MMT was modified with quaternary ammonium salt, trimethyl octadecyl ammonium bromide (TMOD), and boron compounds, boron nitride (BN), zinc borate (ZB), or phenylboronic acid (PBA) were adsorbed on organomodified MMT (OMMT). Then, poly (lactic acid) (PLA) based nanofibrous PLA-OMMT/B composites were fabricated via electrospinning. Modification of MMT nanoparticles with TMOD occurred through ion-exchange reaction and led to better homogenous fibrous structures which exhibited dramatic inhibition for gram-positive bacteria. Moreover, composites with ZB and PBA demonstrated both bacteriostatic and bactericidal effects for gram-positive and gram-negative bacteria. The chemical structures of the matrices were evaluated through ATR-FTIR and supported the intercalated composite formation. The thermal and mechanical stabilities of PLA matrices were also enhanced after OMMT and B incorporation. The lowest breaking strain value was recorded for PLA-OMMT/PBA composite compared to other B composites. The 100% and 50% extracts of the PLA-OMMT matrices showed modest cytotoxic effect on the human dermal fibroblasts (NHDF) on the second day culture that probably originated from TMOD. These results demonstrated that PLA-OMMT/B matrices, especially PBA including matrices, can be used as replaceable wound dressings that have limited interaction with cells but exhibit antibacterial activity and support the early stages of wound healing both morphologically and chemically.

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

Introduction

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

Purpose

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

Methods

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

Results

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

Conclusion

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

Electrospun fibers as carriers for topical drug delivery and release in skin bandages and patches for atopic dermatitis treatment

The skin is a complex layer system and the most important barrier between the environment and the organism. In this review, we describe some widespread skin problems, with a focus on eczema, which are affecting more and more people all over the world. Most of treatment methods for atopic dermatitis (AD) are focused on increasing skin moisture and protecting from bacterial infection and external irritation. Topical and transdermal treatments have specific requirements for drug delivery. Breathability, flexibility, good mechanical properties, biocompatibility, and efficacy are important for the patches used for skin. Up to today, electrospun fibers are mostly used for wound dressing. Their properties, however, meet the requirements for skin patches for the treatment of AD. Active agents can be incorporated into fibers by blending, coaxial or side-by-side electrospinning, and also by physical absorption post-processing. Drug release from the electrospun membranes is affected by drug and polymer properties and the technique used to combine them into the patch. We describe in detail the in vitro release mechanisms, parameters affecting the drug transport, and their kinetics, including theoretical approaches. In addition, we present the current research on skin patch design. This review summarizes the current extensive know-how on electrospun fibers as skin drug delivery systems, while underlining the advantages in their prospective use as patches for atopic dermatitis. This article is categorized under: Implantable Materials and Surgical Technologies > Nanomaterials and Implants Implantable Materials and Surgical Technologies > Nanotechnology in Tissue Repair and Replacement Therapeutic Approaches and Drug Discovery > Emerging Technologies.

Green approaches for extraction, chemical modification and processing of marine polysaccharides for biomedical applications

Over the past few decades, natural-origin polysaccharides have received increasing attention across different fields of application, including biomedicine and biotechnology, because of their specific physicochemical and biological properties that have afforded the fabrication of a plethora of multifunctional devices for healthcare applications. More recently, marine raw materials from fisheries and aquaculture have emerged as a highly sustainable approach to convert marine biomass into added-value polysaccharides for human benefit. Nowadays, significant efforts have been made to combine such circular bio-based approach with cost-effective and environmentally-friendly technologies that enable the isolation of marine-origin polysaccharides up to the final construction of a biomedical device, thus developing an entirely sustainable pipeline. In this regard, the present review intends to provide an up-to-date outlook on the current green extraction methodologies of marine-origin polysaccharides and their molecular engineering toolbox for designing a multitude of biomaterial platforms for healthcare. Furthermore, we discuss how to foster circular bio-based approaches to pursue the further development of added-value biomedical devices, while preserving the marine ecosystem.

Recent advancements and perspective of ciprofloxacin-based antimicrobial polymers

In recent years, microbial pathogens, which are major sources of infections, have become a widespread concern across the world. The number of deaths caused by infectious diseases is continually rising, according to World Health Organization records. Antimicrobial resistance, particularly resistance to several drugs, is steadily growing in percentages of organisms. Ciprofloxacin is a second-generation fluoroquinolone with significant antimicrobial activity and pharmacokinetic characteristics. According to studies, many bacteria are resistant to the antibiotic ciprofloxacin. In this article, we look into polymers as ciprofloxacin macromolecular carriers with a wide range of antibacterial activity. We also discuss the latter form of coupling, in which ciprofloxacin and polymers are covalently bonded. This article also discusses the use of antimicrobial polymers in combination with ciprofloxacin in a various sectors. The current review article provides an overview of publications in the last five years on polymer loaded or modified with ciprofloxacin having applications in numerous sectors.

Essential Oil—Loaded Nanofibers for Pharmaceutical and Biomedical Applications: A Systematic Mini-Review

Essential oils (EOs) have been widely exploited for their biological properties (mainly as antimicrobials) in the food industry. Encapsulation of EOs has opened the way to the utilization of EOs in the pharmaceutical and biomedical fields. Electrospinning (ES) has proved a convenient and versatile method for the encapsulation of EOs into multifunctional nanofibers. Within the last five years (2017–2022), many research articles have been published reporting the use of ES for the fabrication of essential oil—loaded nanofibers (EONFs). The objective of the present mini-review article is to elucidate the potential of EONFs in the pharmaceutical and biomedical fields and to highlight their advantages over traditional polymeric films. An overview of the conventional ES and coaxial ES technologies for the preparation of EONFs is also included. Even though EONFs are promising systems for the delivery of EOs, gaps in the literature can be recognized (e.g., stability studies) emphasizing that more research work is needed in this field to fully unravel the potential of EONFs.

Comparison of Nozzle-Based and Nozzle-Free Electrospinning for Preparation of Fast-Dissolving Nanofibers Loaded with Ciprofloxacin

The study aimed to prepare ciprofloxacin-loaded polyvinylpyrrolidone electrospun nanofibers for oral drug delivery, using a conventional nozzle-based and a lab-built nozzle-free electrospinning equipment. To produce nanofibers, electrospinning is the process most often used. However, from the industry’s point of view, conventional electrospinning does not have sufficiently high productivity. By omitting the nozzle, productivity can be increased, and so the development of nozzle-free processes is worthwhile. In this study, a solution of ciprofloxacin and polyvinylpyrrolidone was electrospun under similar conditions, using both single-nozzle and nozzle-free methods. The two electrospinning methods were compared by investigating the morphological and physicochemical properties, homogeneity, in vitro drug release, and cytotoxicity. The stability of the nanofibers was monitored from different aspects in a 26 month stability study. The results showed that the use of the nozzle-free electrospinning was preferable due to a higher throughput, improved homogeneity, and the enhanced stability of nanofiber mats, compared to the nozzle-based method. Nevertheless, fast dissolving nanofibers loaded with poorly water-soluble ciprofloxacin were produced by both electrospinning methods. The beneficial properties of these nanofibers can be exploited in innovative drug development; e.g., nanofibers can be formulated into orodispersible films or per os tablets.

Polysaccharide-based nanofibers for pharmaceutical and biomedical applications: A review

Nanofibers are fibrous nanocarriers that can be synthesized from natural polymers, synthetic polymers, semiconducting materials, composite materials, and carbon-based materials. Recently, natural polysaccharides-based nanofibers are gaining attention in the field of pharmaceuticals and biomedical as these are biocompatible, biodegradable, non-toxic, and economic. Nanofibers can deliver a significant amount of drug to the targeted site and provide effective interaction of therapeutic agent at the site of action due to a larger surface area. Other important advantages of nanofibers are low density, high porosity, small pore size, high mechanical strength, and low cost. In this review, natural polysaccharides such as alginate, pullulan, hyaluronic acid, dextran, cellulose, chondroitin sulfate, chitosan, xanthan gum, and gellan gum are discussed for their characteristics, pharmaceutical utility, and biomedical applications. The authors have given particular emphasis to the several fabrication processes that utilize these polysaccharides to form nanofibers, and their recent updates in pharmaceutical applications such as drug delivery, tissue engineering, skin disorders, wound-healing dressings, cancer therapy, bioactive molecules delivery, anti-infectives, and solubility enhancement. Despite these many advantages, nanofibers have been explored less for their scale-up and applications in advanced therapeutic delivery.

Electrospinning Drug-Loaded Alginate-Based Nanofibers towards Developing a Drug Release Rate Catalog

Electrospinning natural polymers represents a developing interest in the field of biomaterials. Electrospun nanofibers have been shown to facilitate tissue regeneration and emulate body tissue, making them ideal for modern biomedical applications. These water-soluble natural polymers including alginate, have also shown promise as drug delivery vehicles. However, many biopolymers including alginate are inherently charged, making the formation of nanofibers difficult. To better understand the potential of natural polymer-based fibers in drug delivery applications, fiber formulations and drug loading concentrations of alginate-based scaffolds were investigated. It was found electrospinning poly(vinyl alcohol) with alginate facilitated fiber formation while the co-polymer agarose showed minor improvement in terms of alginate electrospinnability. Once uniform fibers were formed, the antibiotic ciprofloxacin was added into the polymer electrospinning solution to yield drug-loaded nanofibers. These optimized parameters coupled with small molecule release rate data from the drug-loaded, alginate-based fibers have been used to establish a catalog of small molecule release profiles. In the future, this catalog will be further expanded to include drug release rate data from other innately charged natural polymer-based fibers such as chitosan. It is anticipated that the cataloged profiles can be applied in the further development of biomaterials used in drug delivery.

ELECTROSPUN SODIUM ALGINATE/POLY(ETHYLENE OXIDE) NANOFIBERS FOR WOUND HEALING APPLICATIONS: CHALLENGES AND FUTURE DIRECTIONS

Alginate is an interesting natural biopolymer to be considered for biomedical applications due to its advantages and good biological properties. These biological properties make electrospun alginate nanofibers suitable for various uses in the biomedical field, such as wound healing dressings, drug delivery systems, or both. Unfortunately, the fabrication of alginate nanofibers by electrospinning is very challenging because of the high viscosity of the solution, high surface tension and rigidity in water due to hydrogen bonding, and also their diaxial linkages. This review presents an overview of the factors affecting the electrospinning process of sodium alginate/poly(ethylene oxide) (SA/PEO), the application of SA/PEO in drug delivery systems for wound healing applications, and the degradation and swelling properties of SA/PEO. The challenges and future directions of SA/PEO in the medical field are also discussed.

Self-Enriching Electrospun Biosensors for Impedimetric Sensing of Zika Virus

Zika virus (ZIKV) infection is associated with the Guillain-Barré syndrome, and when non-vector congenital transmission occurs, fetal brain abnormalities are expected. After ZIKV infection, the blood, breast milk, and other body fluids contain low viral loads. Their detection is challenging as it requires the processing of larger input volumes of the clinical samples. Pre-enrichment is a valuable strategy to increase the analyte concentration. Therefore, the authors propose the use of a hierarchal composite polyaniline-(electrospun nanofiber) hydrogel mat (ENM) for the simultaneous enrichment and impedimetric sensing of ZIKV viral particles. The electrospinning conditions of polyvinyl alcohol and alginate, including blend formulation, were optimized through a factorial design. Disintegration and gelatinization were controlled via cross-linking to improve the hydrogel properties. Hierarchization was achieved by in situ chemical deposition of conductive polyaniline. The carboxyl groups of the ENM were used for the covalent immobilization of anti-ZIKV polyclonal antibodies used in the specific recognition of ZIKV within the medium of Vero cell culture. The specific capture and desorption of virions were studied at different pHs. ENMs were characterized by scanning electron microscopy and FTIR. Atomic force microscopy along with UV-vis and electrochemical impedance spectroscopies was used to monitor the antibody immobilization, ZIKV capture, and elution processes. Our results show that 14.2 mg (0.25 cm³) of ENM can capture 38.7 ± 2.5 μg of ZIKV with a desorption rate of 99.97% (38.29 ± 2.7 μg ZIKV), which is reusable for at least three times. Therefore, the capture capacity (micrograms of ZIKV captured per milligram of ENM) of polyaniline-hierarchized mats was 2.72 μg ZIKV/mg. The impedance LOD value was determined to be 2.76 μg of ZIKV particles (approximately 6.6 × 103 PFU/mL). As a result, we present a fast small-scale purification system that can simultaneously monitor ZIKV electrochemically and optically.

A review on Biopolymer-derived Electrospun Nanofibers for Biomedical and Antiviral Applications

Unique aspects of polymer-derived nanofibers provide significant potential in the area of biomedical and health care applications. Much research has demonstrated several plausible nanofibers to overcome the modern-day challenges in...

Photoactive electrospun cellulose acetate/polyethylene oxide/methylene blue and trilayered cellulose acetate/polyethylene oxide/silk fibroin/ciprofloxacin nanofibers for chronic wound healing

This study aimed to synthesize cellulose acetate (CA)-based electrospun nanofibers as drug delivery dressings for chronic wound healing. For the first time, CA was blended with polyethylene oxide (PEO) using acetone and formic acid. Methylene blue (MB) was incorporated into monolayered random CA/PEO nanofibers. They had a diameter of 400-600 nm, were hydrophilic, and generated reactive oxygen species upon irradiation. Thus, they mediated antimicrobial photodynamic inactivation (aPDI) against isolated biofilm-forming Staphylococcus aureus, Klebsiella pneumoniae, and Pseudomonas aeruginosa. Bacterial survival, biofilm mass, and produced pyocyanin of the treated groups declined by 90%, 80%, and 3 folds, respectively. On the other hand, ciprofloxacin (Cipro) was loaded into an innovative trilayered aligned nanofiber consisting of CA/PEO surrounding a blank layer of silk fibroin. Cipro and MB release followed the Korsmeyer-Peppas model. An infected diabetic wound mouse model was established and treated with either MB-aPDI or Cipro. A combined therapy group of MB-aPDI followed by Cipro was included. The combined therapy showed significantly better results than monotherapies delineated by elevation in re-epithelization, collagen deposition, CD34, and TGF-β expression, along with a decline in CD95+ cells. This study deduced that drug-loaded CA electrospun nanofibers might be exploited in multimodal chronic wound healing.

Nanofiber as a novel vehicle for transdermal delivery of therapeutic agents: challenges and opportunities

Background

Transdermal delivery of drugs is a quite challenging task for pharmaceutical scientists. The transdermal route is preferred over the oral route due to various advantages like avoidance of the first-pass effect, non-invasiveness, and high patient compliance. Therefore, it is necessary to develop an effective carrier system that enables the effective passage of the drug through the dermal barrier.

Main body of abstract

Various novel drug delivery systems are used to enhance the permeation of a variety of drugs through the skin barrier. Researchers around the globe have explored nanofibers for the transdermal delivery of various therapeutic agents. Nanofibers are designed to have a high concentration of therapeutic agents in them promoting their flux through various skin layers. Polymeric nanofibers can be explored for the loading of both hydrophilic and lipophilic drugs. Biopolymer-based nanofibers have been also explored for transdermal delivery. They are capable of controlling the release of therapeutic agents for a prolonged time.

Short conclusion

The literature presented in this review paper provides significant proof that nanofibers will have an intense impact on the transdermal delivery of different bioactive molecules in the future.

Graphic abstract

Alginate and alginate composites for biomedical applications

Alginate is an edible heteropolysaccharide that abundantly available in the brown seaweed and the capsule of bacteria such as Azotobacter sp. and Pseudomonas sp. Owing to alginate gel forming capability, it is widely used in food, textile and paper industries; and to a lesser extent in biomedical applications as biomaterial to promote wound healing and tissue regeneration. This is evident from the rising use of alginate-based dressing for heavily exuding wound and their mass availability in the market nowadays. However, alginate also has limitation. When in contact with physiological environment, alginate could gelate into softer structure, consequently limits its potential in the soft tissue regeneration and becomes inappropriate for the usage related to load bearing body parts. To cater this problem, wide range of materials have been added to alginate structure, producing sturdy composite materials. For instance, the incorporation of adhesive peptide and natural polymer or synthetic polymer to alginate moieties creates an improved composite material, which not only possesses better mechanical properties compared to native alginate, but also grants additional healing capability and promote better tissue regeneration. In addition, drug release kinetic and cell viability can be further improved when alginate composite is used as encapsulating agent. In this review, preparation of alginate and alginate composite in various forms (fibre, bead, hydrogel, and 3D-printed matrices) used for biomedical application is described first, followed by the discussion of latest trend related to alginate composite utilization in wound dressing, drug delivery, and tissue engineering applications.

Design of new bioinspired GO-COOH decorated alginate/gelatin hybrid scaffolds with nanofibrous architecture: structural, mechanical and biological investigations

The current research study deals with the design and investigation of novel bioinspired and biocompatible GO-COOH decorated hybrid polymeric scaffolds with nanofibrous architecture as biomaterials with highly appropriate features for functional restoration of damaged tissue. Gelatin and alginate, two biobased-polymers with excellent biocompatibility, high microenvironment biomimicry and ability for proper guidance of cell development in combination with carboxylated graphene oxide (GO-COOH), embody the matrix of electrospun hybrid scaffolds. The underlying principle is based on various types of interactions that can take place between the functionalities of the system's entities (proved by DLS) and their synergy in improving the structural integrity, mechanical tailorability and biological performances of the new nanofibrous GO-COOH decorated hybrid scaffolds. The nanofibrous structure along with the presence of GO-COOH are established by SEM. The new covalent bonds formed between various functionalities of the protein-polysaccharide-GO-COOH system are proved by FTIR and XPS. The physico-chemical state of GO-COOH lattices within the hybrid structures is investigated by Raman spectrometry. The interpenetrated network of bicomponent structures determines a 10-fold increase of Young's modulus as compared to monocomponent counterparts while the dispersion of GO-COOH significantly increases the elasticity of materials. The biological results (MTT and LDH assays) indicate a good cytocompatibility of crosslinked bicomponent AGS scaffolds; the metabolic cellular activity is substantially improved following the GO-COOH addition, suggesting that GO-COOH can support the cell adhesion, growth and proliferation.

Simple and green synthesis of calcium alginate/AgCl nanocomposites with low-smoke flame-retardant and antimicrobial properties

Fire hazards and infectious diseases result in great threats to public safety and human health, thus developing multi-functional materials to deal with these issues is critical and yet has remained challenging to date. In this work, we report a facile and eco-friendly synthetic approach for the preparation of calcium alginate/silver chloride (CA/AgCl) nanocomposites with dual functions of excellent flame-retardant and antibacterial activity. Multi characterization techniques and antibacterial assays were performed to investigate the flame-retardant and antibacterial properties of the CA/AgCl nanocomposites. The obtained results show that the CA/AgCl nanocomposites exhibited much higher limiting oxygen index value (> 60%) than that of CA (48%) with a UL-94 rating of V-0. Moreover, CA/AgCl particularly displayed an efficiently smoke-suppressive feature by achieving a total smoke release value of 2.7 m²/m², which was reduced by 91%, compared to CA. The antibacterial rates of the CA/AgCl nanocomposites against E. coli and S. aureus were measured to be 99.67% and 99.77%, respectively, while CA showed quite weak antibacterial rates. In addition, the flame-retardant and antibacterial mechanisms were analyzed and proposed based on the experimental data. This study provides a novel nanocomposite material with both flame-retardant and antibacterial properties which show promising application prospects in the fields of decorative materials and textile industry.

How does counter-cation substitution influence inter- and intramolecular hydrogen bonding and electrospinnability of alginates

Despite numerous applications of nanofibrous alginate (Alg) mat, its facile fabrication via electrospinning is still challenging. The low alginate content compared to the carrier polymer and existence of impurities are the main drawbacks of existing approaches. The purpose of this research is both to study and improve alginate electrospinnability by focusing on the effect of inter- and intramolecular hydrogen bonding. Based on hard and soft acids and bases (HSAB) theory, the Na⁺ cations (carboxylate counter-cation) were substituted with a harder acid, Li⁺ cation, to increase the strength of ionic interaction and decrease the density of hydrogen bonding. Viscosity and electrical conductivity measurements as well as FTIR and ¹H NMR revealed a lower intramolecular hydrogen bonding density in Li-Alg. SEM images showed improvement of alginate electrospinnability for Li-Alg compared to the salts of Na-Alg and K-Alg. This study sheds more light on underlying reasons hindering alginate electrospinning and introduces a simple method for fabrication of nanofibers with high alginate content.

Nanofiber Technology for Regenerative Engineering

Regenerative engineering is powerfully emerging as a successful strategy for the regeneration of complex tissues and biological organs using a convergent approach that integrates several fields of expertise. This innovative and disruptive approach has spurred the demands for more choice of biomaterials with distinctive biological recognition properties. An ideal biomaterial is one that closely mimics the hierarchical architecture and features of the extracellular matrices (ECM) of native tissues. Nanofabrication technology presents an excellent springboard for the development of nanofiber scaffolds that can have positive interactions in the immediate cellular environment and stimulate specific regenerative cascades at the molecular level to yield healthy tissues. This paper systematically reviews the electrospinning process technology and its utility in matrix-based regenerative engineering, focusing mainly on musculoskeletal tissues. It briefly outlines the electrospinning/three-dimensional printing system duality and concludes with a discussion on the technology outlook and future directions of nanofiber matrices.

Electrospun vancomycin-loaded nanofibers for management of methicillin-resistant Staphylococcus aureus-induced skin infections

Skin damage exposes the underlying layers to bacterial invasion, leading to skin and soft tissue infections. Several pathogens have developed resistance against conventional topical antimicrobial treatments and rendered them less effective. Recently, several nanomedical strategies have emerged as a potential approach to improve therapeutic outcomes of treating bacterial skin infections. In the current study, nanofibers were utilized for topical delivery of the antimicrobial drug vancomycin and evaluated as a promising tool for treatment of topical skin infections. Vancomycin-loaded nanofibers were prepared via electrospinning technique, and vancomycin-loaded nanofibers of the optimal composition exhibited nanosized uniform smooth fibers (ca. 200 nm diameter), high drug entrapment efficiency and sustained drug release patterns over 48 h. In vitro cytotoxicity assays, using several cell lines, revealed the biocompatibility of the drug-loaded nanofibers. In vitro antibacterial studies showed sustained antibacterial activity of the vancomycin-loaded nanofibers against methicillin-resistant Staphylococcus aureus (MRSA), in comparison to the free drug. The nanofibers were then tested in animal model of superficial MRSA skin infection and demonstrated a superior antibacterial efficiency, as compared to animals treated with the free vancomycin solution. Hence, nanofibers might provide an efficient nanodevice to overcome MRSA-induced skin infections and a promising topical delivery vehicle for antimicrobial drugs.

A novel hemostat and antibacterial nanofibrous scaffold based on poly(vinyl alcohol)/poly(lactic acid)

Today, an advanced wound dressing with the ability of blood clotting and antibacterial activity is the main subject of many studies to consider their necessity in modern society. In this study, it was aimed to present a novel scaffold with both abilities simultaneously. Poly(vinyl alcohol)/poly(lactic acid) nanofibrous scaffolds containing ceftriaxone antimicrobial agent (PVA-CTX/PLA) and tranexamic acid coagulant (PVA-CTX-TXA/PLA) were fabricated by electrospinning method. Morphology, antimicrobial activity, blood coagulation and bioavailability indexes, and swelling ability (gel formation) of produced samples were determined. Morphological results showed that the hybrid nanofibers were form successfully. The antibacterial efficiency of them against Gram-negative ( Escherichia coli) and Gram-positive ( Staphylococcus aureus) bacteria was more than 90% for PVA-CTX/PLA and it reached 100% for PVA-CTX-TXA/PLA. Both PVA-CTX-TXA/PLA and PVA-TXA/PLA scaffolds showed acceptable blood coagulation ability with an average absorption of 0.043 and 0.036 nm, respectively. PVA-CTX-TXA/PLA scaffolds had a gel formation ability of about 45 min. All scaffolds were successful in cell proliferation (L929 fibroblast cell) after 48 h.

Electrospinning Highly Concentrated Sodium Alginate Nanofibres without Surfactants by Adding Fluorescent Carbon Dots

In this study, sodium alginate (SA) nanofibres were obtained by electrospinning via the assistance of traditional poly(ethyl oxide) (PEO) and dimethyl sulfoxide (DMSO) with a high SA/PEO ratio of up to 94:6. However, surfactants with more or less toxicities were replaced by nontoxic and fluorescent carbon dots (CDs) to improve spinnability. Experimental details were conducted by fixing the ratio of SA/PEO to 90:10. Then, the electrospinning products of solutions with different compositions were observed with scanning electron microscopy. Properties such as conductivity, surface tension and rheology of the solutions were investigated to determine the key influencing factors. Moreover, since CDs have excellent fluorescence properties, the fluorescent properties of the nanofibre membrane that was blended with CDs were then collected. In addition, in vitro cytotoxicity assessment of the nanofibres were conducted to evaluate the toxicities and biocompatibility.

Electrospun Alginate Nanofibers Toward Various Applications: A Review

Alginate has been a material of choice for a spectrum of applications, ranging from metal adsorption to wound dressing. Electrospinning has added a new dimension to polymeric materials, including alginate, which can be processed to their nanosize levels in order to afford unique nanostructured materials with fascinating properties. The resulting nanostructured materials often feature high porosity, stability, permeability, and a large surface-to-volume ratio. In the present review, recent trends on electrospun alginate nanofibers from over the past 10 years toward advanced applications are discussed. The application of electrospun alginate nanofibers in various fields such as bioremediation, scaffolds for skin tissue engineering, drug delivery, and sensors are also elucidated.

Applications of Electrospun Nanofibers with Antioxidant Properties: A Review

Antioxidants can be encapsulated to enhance their solubility or bioavailability or to protect them from external factors. Electrospinning has proven to be an excellent option for applications in nanotechnology, as electrospun nanofibers can provide the necessary environment for antioxidant encapsulation. Forty-nine papers related to antioxidants loaded onto electrospun nanofibers were categorized and reviewed to identify applications and new trends. Medical and food fields were commonly proposed for the newly obtained composites. Among the polymers used as a matrix for the electrospinning process, synthetic poly (lactic acid) and polycaprolactone were the most widely used. In addition, natural compounds and extracts were identified as antioxidants that help to inhibit free radical and oxidative damage in tissues and foods. The most recurrent active compounds used were tannic acid (polyphenol), quercetin (flavonoid), curcumin (polyphenol), and vitamin B6 (pyridoxine). The incorporation of active compounds in nanofibers often improves their bioavailability, giving them increased stability, changing the mechanical properties of polymers, enhancing nanofiber biocompatibility, and offering novel properties for the required field. Although most of the polymers used were synthetic, natural polymers such as silk fibroin, chitosan, cellulose, pullulan, polyhydroxybutyrate, and zein have proven to be proper matrices for this purpose.

The application of nanomaterial science in the formulation a novel antibiotic: Assessment of the antifungal properties of mucoadhesive clotrimazole loaded nanofiber versus vaginal films

Candidiasis is the origin of several chronic diseases and causes a wide range of symptoms from mucosal to systemic and deadly infections. Vaginal patches are one of the best drug delivery systems for the treatment of fungal infections in the vaginal environment, so a mucoadhesive film containing drugs such as clotrimazole and metronidazole is commercially available for patients. In the present study, a physicochemical comparison is made between clotrimazole loaded film and nanofiber fabricated with the new hybrid mucoadhesive formulation of dextran and alginate. Toxicity testing was performed using the MTT assay. Bioadhesion and antifungal effects were investigated for fibers and films. The release behavior of clotrimazole from two systems was evaluated by Franz cell in each case. The most important difference between nanofibrous and film mats were obtained in antifungal, mucoadhesive, Young's modulus and morphology. The nanofiber has a higher antifungal effect and two-fold adhesive to the mouse tissue, than film. The inherent flexibility of nanofiber obviated the need for a plasticizer, which may have cytotoxic side effects. The Clotrimazole loaded nanofibrous of Alginate/Dextran mats were successfully electrospun. They exhibited more bioadhesive with higher and faster antifungal properties versus similar formulation film. Further in vivo investigation is required for their application in vaginal candidiasis.

Magnetic proline-based ionic liquid surfactant as a nano-carrier for hydrophobic drug delivery

Biofriendly and magnetic proline based ionic liquid surfactant demonstrated for drug delivery system.