Incorporating small molecules or biologics into nanofibers for optimized drug release: A review

Design and Fabrication of Sustained Bacterial Release Scaffolds to Support the Microbiome

Fibres in the micro- and nanometre scale are suited to a broad range of applications, including drug delivery and tissue engineering. Electrospinning is the manufacturing method of choice, but it has some limitations. Novel pressure-driven fibre-forming techniques, like pressurised gyration (PG), overcome these limitations; however, the compatibility of PG with biological materials has not yet been evaluated in detail. For the first time, this limitation of PG was investigated by optimising PG for microbial cell processing and incorporating bacterial cultures into fibrous polymeric scaffolds for sustained release. Multiple polymer-solvent systems were trialled, including polyvinylpyrrolidone (PVP)/phosphate-buffered saline (PBS) 25% w/v, polyethylene oxide (PEO)/PBS 20% w/v, and PVP/ethanol 20% w/v. Rheological studies revealed the surface tension of the PVP/PBS, PEO/PBS, and PVP/ethanol polymer-solvent systems to be 73.2, 73.9, and 22.6 mN/m, respectively. Scanning electron microscopy showed the median fibre diameters to be between 9.8 μm and 26.1 μm, with PVP producing larger fibres. Overnight Bacillus subtilis cultures were then incorporated into the chosen polymeric solutions and processed into fibres using PG. The produced cell-loaded fibres were incubated in LB broth to assess the cell viability of the encapsulated cells. Colony counts post-incubation showed the PVP/PBS 25% fibres resulted in 60% bacterial growth, and PEO/PBS 20% fibres led to 47% bacterial growth, whereas PVP/ethanol 20% fibres did not lead to any bacterial growth. Based on the results gathered during this study, it can be concluded that PG offers a promising way of encapsulating cells and other sensitive biological products while having many notable advantages compared to electrospinning. This research demonstrates proof of concept research-based evidence and showcases the potential of pressurised gyration as a key disruptive innovation in probiotic delivery system design and manufacturing.

Development and Evaluation of Different Electrospun Cysteamine-Loaded Nanofibrous Webs: A Promising Option for Treating a Rare Lysosomal Storage Disorder

Nanofibers can be utilized to overcome the challenges faced by conventional ophthalmic formulations. This study aimed to develop and characterize cysteamine (Cys)-loaded nanofiber-based ophthalmic inserts (OIs) as a potential candidate for the treatment of ophthalmic cystinosis using water-soluble polyvinyl alcohol (PVA)/poloxamer 407 (PO-407) and water-insoluble tetraethoxysilane (TEOS)/PVA nanofibers. Plain and Cys-loaded fibers in different proportions were prepared by the electrospinning method and studied for their morphological, physicochemical, release study, cytocompatibility effects, and stability study. The fiber formation was confirmed by scanning electron microscopy, while Fourier transform infrared spectra showed the most critical peaks for the Cys and the excipients. The release of the Cys was fast from the two polymeric matrices (≤20 min). The release from TEOS/PVA nanofibers is characterized by Case II transport (0.75 < β < 1), while the release from PVA/PO-407 nanofibers follows Fickian diffusion (β < 0.75). The cytocompatibility of compositions was confirmed by hen eggs tested on the chorioallantoic membrane (HET-CAM) of chick embryos. All formulations remained stable under stress conditions (40 ± 2 °C, 75 ± 5% relative humidity) regarding morphology and physicochemical characteristics. The developed nanofibrous mats could be an excellent alternative to available Cys drops, with better stability and convenience of self-administration as OIs.

Angiogenesis in bone tissue engineering via ceramic scaffolds: A review of concepts and recent advancements

Due to organ donor shortages, long transplant waitlists, and the complications/limitations associated with auto and allotransplantation, biomaterials and tissue-engineered models are gaining attention as feasible alternatives for replacing and reconstructing damaged organs and tissues. Among various tissue engineering applications, bone tissue engineering has become a promising strategy to replace or repair damaged bone. We aimed to provide an overview of bioactive ceramic scaffolds in bone tissue engineering, focusing on angiogenesis and the effect of different biofunctionalization strategies. Different routes to angiogenesis, including chemical induction through signaling molecules immobilized covalently or non-covalently, in situ secretion of angiogenic growth factors, and the degradation of inorganic scaffolds, are described. Physical induction mechanisms are also discussed, followed by a review of methods for fabricating bioactive ceramic scaffolds via microfabrication methods, such as photolithography and 3D printing. Finally, the strengths and weaknesses of the commonly used methodologies and future directions are discussed.

Preparation of astaxanthin-loaded composite micelles with coaxial electrospray technology for enhanced oral bioavailability and improved antioxidation capability

BACKGROUND

Astaxanthin (AST) is approved by the US Food and Drug Administration (FDA) as a safe dietary supplement for humans. As a potent lipid-soluble keto-carotenoid, it is widely used in food, cosmetics, and the pharmaceutical industry. However, its low solubility limits its powerful biological activity and its application in these fields. This study aims to develop a delivery system to address the low solubility and bioavailability of AST and to enhance its antioxidant capacity.

RESULTS

Astaxanthin-loaded composite micelles were successfully prepared via coaxial electrospray technology. Astaxanthin existed in the amorphous state in the electro-sprayed formulation with an approximate particle size of 186.28 nm and with a polydispersity index of 0.243. In this delivery system, Soluplus and copovidone (PVPVA 64) were the main polymeric matrix for AST, which then released the drug upon contact with aqueous media, resulting in an overall increase in drug solubility and a release rate of 94.08%. Meanwhile, lecithin, and Polyethylene glycol-grafted Chitosan (PEG-g-CS) could support the absorption of AST in the gastrointestinal tract, assisting transmembrane transport. The relative bioavailability reached about 308.33% and the reactive oxygen species (ROS) scavenging efficiency of the formulation was 44.10%, which was 1.57 times higher than that of free astaxanthin (28.10%) when both were at the same concentration level based on astaxanthin.

CONCLUSION

Coaxial electrospray could be applied to prepare a composite micelles system for the delivery of poorly water-soluble active ingredients in functional food, cosmetics, and medicine. © 2023 Society of Chemical Industry.

Silk fibroin-derived electrospun materials for biomedical applications: A review

Electrospinning is a versatile technique for fabricating polymeric fibers with diameters ranging from micro- to nanoscale, exhibiting multiple morphologies and arrangements. By combining silk fibroin (SF) with synthetic and/or natural polymers, electrospun materials with outstanding biological, chemical, electrical, physical, mechanical, and optical properties can be achieved, fulfilling the evolving biomedical demands. This review highlights the remarkable versatility of SF-derived electrospun materials, specifically focusing on their application in tissue regeneration (including cartilage, cornea, nerves, blood vessels, bones, and skin), disease treatment (such as cancer and diabetes), and the development of controlled drug delivery systems. Additionally, we explore the potential future trends in utilizing these nanofibrous materials for creating intelligent biomaterials, incorporating biosensors and wearable sensors for monitoring human health, and also discuss the bottlenecks for its widespread use. This comprehensive overview illuminates the significant impact and exciting prospects of SF-derived electrospun materials in advancing biomedical research and applications.

Nanofibers of Glycyrrhizin/Hydroxypropyl-β-Cyclodextrin Inclusion Complex: Enhanced Solubility Profile and Anti-inflammatory Effect of Glycyrrhizin

Despite having a wide range of therapeutic advantages, glycyrrhizin (GL) has few commercial applications due to its poor aqueous solubility. In this study, we combined the benefits of hydroxypropyl β-cyclodextrin (HP-βCD) supramolecular inclusion complexes and electrospun nanofibers to improve the solubility and therapeutic potential of GL. A molecular inclusion complex containing GL and HP-βCD was prepared by lyophilization at a 1:2 molar ratio. GL and hydroxypropyl β-cyclodextrin inclusion complexes were also incorporated into hyaluronic acid (HA) nanofibers. Prepared NF was analyzed for physical, chemical, thermal, and pharmaceutical properties. Additionally, a rat model of carrageenan-induced hind paw edema and macrophage cell lines was used to evaluate the anti-inflammatory activity of GL-HP-βCD NF. The DSC and XRD analyses clearly showed the amorphous state of GL in nanofibers. In comparison to pure GL, GL-HP-βCD NF displayed improved release (46.6 ± 2.16% in 5 min) and dissolution profiles (water dissolvability ≤ 6 s). Phase solubility results showed a four-fold increase in GL solubility in GL-HP-βCD NF. In vitro experiments on cell lines showed that inflammatory markers like IL-1β, TNF-α, and IL-6 were significantly lower in GL-HP-βCD NF compared to pure GL (p < 0.01 and p < 0.05). According to in vivo results, the prepared nanofiber exhibits a better anti-inflammatory effect than pure GL (63.4% inhibition vs 53.7% inhibition). The findings presented here suggested that GL-HP-βCD NF could serve as a useful strategy for improving the therapeutic effects of GL.

Research progress of polyphenols in nanoformulations for antibacterial application

Infectious disease is one of the top 10 causes of death worldwide, especially in low-income countries. The extensive use of antibiotics has led to an increase in antibiotic resistance, which poses a critical threat to human health globally. Natural products such as polyphenolic compounds and their derivatives have been shown the positive therapeutic effects in antibacterial therapy. However, the inherent physicochemical properties of polyphenolic compounds and their derivatives limit their pharmaceutical effects, such as short half-lives, chemical instability, low bioavailability, and poor water solubility. Nanoformulations have shown promising advantages in improving antibacterial activity by controlling the release of drugs and enhancing the bioavailability of polyphenols. In this review, we listed the classification and antibacterial mechanisms of the polyphenolic compounds. More importantly, the nanoformulations for the delivery of polyphenols as the antibacterial agent were summarized, including different types of nanoparticles (NPs) such as polymer-based NPs, metal-based NPs, lipid-based NPs, and nanoscaffolds such as nanogels, nanofibers, and nanoemulsions. At the same time, we also presented the potential biological applications of the nano-system to enhance the antibacterial ability of polyphenols, aiming to provide a new therapeutic perspective for the antibiotic-free treatment of infectious diseases.

Electrospun Scaffolds Enriched with Nanoparticle-Associated DNA: General Properties, DNA Release and Cell Transfection

Biomaterial-mediated, spatially localized gene delivery is important for the development of cell-populated scaffolds used in tissue engineering. Cells adhering to or penetrating into such a scaffold are to be transfected with a preloaded gene that induces the production of secreted proteins or cell reprogramming. In the present study, we produced silica nanoparticles-associated pDNA and electrospun scaffolds loaded with such nanoparticles, and studied the release of pDNA from scaffolds and cell-to-scaffold interactions in terms of cell viability and pDNA transfection efficacy. The pDNA-coated nanoparticles were characterized with dynamic light scattering and transmission electron microscopy. Particle sizes ranging from 56 to 78 nm were indicative of their potential for cell transfection. The scaffolds were characterized using scanning electron microscopy, X-ray photoelectron spectroscopy, stress-loading tests and interaction with HEK293T cells. It was found that the properties of materials and the pDNA released vary, depending on the scaffold's composition. The scaffolds loaded with pDNA-nanoparticles do not have a pronounced cytotoxic effect, and can be recommended for cell transfection. It was found that (pDNA-NPs) + PEI9-loaded scaffold demonstrates good potential for cell transfection. Thus, electrospun scaffolds suitable for the transfection of inhabiting cells are eligible for use in tissue engineering.

Evolving Trends in Nanofibers for Topical Delivery of Therapeutics in Skin Disorders

Nanotechnology has yielded nanostructure-based drug delivery approaches, among which nanofibers have been explored and researched for the potential topical delivery of therapeutics. Nanofibers are filaments or thread-like structures in the nanometer size range that are fabricated using various polymers, such as natural or synthetic polymers or their combination. The size or diameter of the nanofibers depends upon the polymers, the techniques of preparation, and the design specification. The four major processing techniques, phase separation, self-assembly, template synthesis, and electrospinning, are most commonly used for the fabrication of nanofibers. Nanofibers have a unique structure that needs a multimethod approach to study their morphology and characterization parameters. They are gaining attention as drug delivery carriers, and the substantially vast surface area of the skin makes it a potentially promising strategy for topical drug products for various skin disorders such as psoriasis, skin cancers, skin wounds, bacterial and fungal infections, etc. However, the large-scale production of nanofibers with desired properties remains challenging, as the widely used electrospinning processes have certain limitations, such as poor yield, use of high voltage, and difficulty in achieving in situ nanofiber deposition on various substrates. This review highlights the insights into fabrication strategies, applications, recent clinical trials, and patents of nanofibers for different skin disorders in detail. Additionally, it discusses case studies of its effective utilization in the treatment of various skin disorders for a better understanding for readers.

Rotary Jet Spinning (RJS): A Key Process to Produce Biopolymeric Wound Dressings

Wounds result from different causes (e.g., trauma, surgeries, and diabetic ulcers), requiring even extended periods of intensive care for healing, according to the patient's organism and treatment. Currently, wound dressings generated by polymeric fibers at micro and nanometric scales are promising for healing the injured area. They offer great surface area and porosity, mimicking the fibrous extracellular matrix structure, facilitating cell adhesion, migration, and proliferation, and accelerating the wound healing process. Such properties resulted in countless applications of these materials in biomedical and tissue engineering, also as drug delivery systems for bioactive molecules to help tissue regeneration. The techniques used to engineer these fibers include spinning methods (electro-, rotary jet-), airbrushing, and 3D printing. These techniques have important advantages, such as easy-handle procedure and process parameters variability (type of polymer), but encounter some scalability problems. RJS is described as a simple and low-cost technique resulting in high efficiency and yield for fiber production, also capable of bioactive agents' incorporation to improve the healing potential of RJS wound dressings. This review addresses the use of RJS to produce polymeric fibers, describing the concept, type of configuration, comparison to other spinning techniques, most commonly used polymers, and the relevant parameters that influence the manufacture of the fibers, for the ultimate use in the development of wound dressings.

Smart Thermoresponsive Electrospun Nanofibers with On-Demand Release of Carbon Quantum Dots for Cellular Uptake

Developing a smart responsive surface for on-demand delivery of organic, inorganic, and biological cargo in vitro cellular uptake is always in constant demand. Herein, we present carbon quantum dot (CQD)-loaded (poly(N-isopropylacrylamide) (PNIPAAm)/poly(methyl methacrylate (PMMA)) blend nanofiber sheets having a thermoresponsive nature. As a model cargo, fluorescent CQDs are used for the demonstration of the on-demand delivery mechanism. In addition, a thermoresponsive nature is produced by the PNIPAAm polymer in the nanofiber matrix while the PMMA polymer provides extra stability and firmness to the nanofibers against the sudden dissolution of the nanofibers in aqueous media. The synthesis of CQDs and their loading into a blend nanofiber matrix are confirmed using fluorescence spectrophotometry, transmission electron microscopy, and fluorescence microscopy. The morphologies and diameters of the nanofibers are analyzed by scanning electron microscopy. Burst effect analysis proves that 30% (w/w) PNIPAAm-containing nanofibers possess the highest stability with the least dissolution in aqueous media. Thermoresponsiveness of the nanofibers is further confirmed through water contact angle measurements. Quantitative fluorescence results show that more than 80% of loaded CQDs can be released upon thermal stimulation. The fluorescence micrographs reveal that the blend nanofiber sheets can effectively improve the cellular uptake of CQDs by simply increasing the local concentrations via applying thermal stimulation as the released mechanism.

Emulsion electrospinning of sodium alginate/poly(ε-caprolactone) core/shell nanofibers for biomedical applications

Electrospun nanofibers have shown great potential as drug vehicles and tissue engineering scaffolds. However, the successful encapsulation of multiple hydrophilic/hydrophobic therapeutic compounds is still challenging. Herein, sodium alginate/poly(ε-caprolactone) core/shell nanofibers were fabricated via water-in-oil emulsion electrospinning. The sodium alginate concentration, water-to-oil ratio, and surfactant concentration were optimized for the maximum stability of the emulsion. The results demonstrated that an increasing water-to-oil ratio results in more deviation from Newtonian fluid and leads to a broader distribution of the fibers' diameters. Moreover, increasing poly(ε-caprolactone) concentration increases loss and storage moduli and increases the diameter of the resulting fibers. The nanofibers' characteristics were investigated by scanning electron microscopy, transmission electron microscopy, confocal laser scanning microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, and water contact angle measurements. It was observed that using an emulsion composition of 10% (w/v) PCL and a water-to-oil ratio of 0.1 results in smooth, cylindrical, and uniform core/shell nanofibers with PCL in the shell and ALG in the core. The in vitro cell culture study demonstrated the favorable biocompatibility of nanofibers. Overall, this study provides a promising and trustworthy material for biomedical applications.

Preparation and Characterization of Doxycycline-Loaded Electrospun PLA/HAP Nanofibers as a Drug Delivery System

The present study aimed to prepare nanofibers by electrospinning in the system polylactic acid-hydroxyapatite-doxycycline (PLA-HAP-Doxy) to be used as a drug delivery vehicle. Two different routes were employed for the preparation of Doxy-containing nanofibers: Immobilization on the electrospun mat’s surface and encapsulation in the fiber structure. The nanofibers obtained by Doxy encapsulation were characterized using Fourier transform infrared (FTIR) spectroscopy, thermogravimetric (TG) and differential thermal analyses (DTA) and scanning electron microscopy (SEM). The adsorption properties of pure PLA and PLA-HAP nanofibers were investigated for solutions with different Doxy concentrations (3, 7 and 12 wt%). Moreover, the desorption properties of the active substance were tested in two different fluids, simulated body fluid (SBF) and phosphate buffer solution (PBS), to evidence the drug release properties. In vitro drug release studies were performed and different drug release kinetics were assessed to confirm the use of these nanofiber materials as efficient drug delivery vehicles. The obtained results indicate that the PLA-HAP-Doxy is a promising system for biomedical applications, the samples with 3 and 7 wt% of Doxy-loaded PLA-HAP nanofibers prepared by physical adsorption are the most acceptable membranes to provide prolonged release in PBS/SBF rather than an immediate release of Doxy.

Physicomechanical characterization and tablet compression of theophylline nanofibrous mats prepared by conventional and ultrasound enhanced electrospinning

Theophylline (TEO) nanofibers with polyethylene oxide (PEO) were prepared by conventional electrospinning (ES) and novel needleless ultrasound-enhanced electrospinning (USES). They were compared for Young's modulus, elongation at rupture and rupture stress, tabletability and drug release. Placebo (PEO) or drug-loaded (PEO/TEO 90:10) nanofibers were examined by scanning electron microscopy (SEM), powder X-ray diffraction (PXRD), differential scanning calorimetry (DSC) and infrared spectroscopy (ATR-FTIR). Nanofibers prepared by USES were thinner than ES nanofibers and drug-loaded nanofibers thinner than placebo. Drug was mostly amorphous and interacted weakly with PEO. Mats generated by USES and also drug-loaded mats demonstrated higher Young's modulus (stiffness) and higher rupture stress. Under compression, USES and drug-loaded nanofibers demonstrated greater compaction work, higher yield pressure (Heckel and K-L models), and produced stronger tablets than ES and placebo respectively. Principal Component Analysis revealed two significant components explaining 91.05% of the variance. The first comprised the compaction work, yield pressure (ductility) and Young's modulus that were positively intercorrelated and elongation at rupture that was correlated negatively. The second comprised the mat rupture stress and tablet breaking load. Drug release from nanofibrous tablets was faster than tablets of physical mixture but there was no difference between the tablets of the two electrospinning methods.

Nanofiber Systems as Herbal Bioactive Compounds Carriers: Current Applications in Healthcare

Nanofibers have emerged as a potential novel platform due to their physicochemical properties for healthcare applications. Nanofibers’ advantages rely on their high specific surface-area-to-volume and highly porous mesh. Their peculiar assembly allows cell accommodation, nutrient infiltration, gas exchange, waste excretion, high drug release rate, and stable structure. This review provided comprehensive information on the design and development of natural-based polymer nanofibers with the incorporation of herbal medicines for the treatment of common diseases and their in vivo studies. Natural and synthetic polymers have been widely used for the fabrication of nanofibers capable of mimicking extracellular matrix structure. Among them, natural polymers are preferred because of their biocompatibility, biodegradability, and similarity with extracellular matrix proteins. Herbal bioactive compounds from natural extracts have raised special interest due to their prominent beneficial properties in healthcare. Nanofiber properties allow these systems to serve as bioactive compound carriers to generate functional matrices with antimicrobial, anti-inflammatory, antioxidant, antiseptic, anti-viral, and other properties which have been studied in vitro and in vivo, mostly to prove their wound healing capacity and anti-inflammation properties.

Preparation and functional evaluation of electrospun polymeric nanofibers as a new system for sustained topical ocular delivery of itraconazole

Due to the rapid clearance of external agents from the surface of the cornea, conventional ocular formulations usually require frequent and long duration of administration to achieve a therapeutic level of the drug on the cornea which can be conquered using prolonged-release nanofibrous inserts. In the present study, for the first time, polymeric nanofibers of itraconazole (ITZ), a potent triazole antifungal agent, were prepared as ocular inserts to enhance the topical ocular delivery of the drug. Three different nanofibers were prepared by electrospinning using polyvinyl alcohol-cellulose acetate and polycaprolactone-polyethylene glycol 12 000 polymeric blends. Nanofibers indicated uniform structures with the mean diameter ranging between 137 and 180 nm. Differential scanning calorimetry and Fourier-transform infrared spectroscopy confirmed the amorphous state of the drug in the formulations and the no drug-polymer interaction. Appropriate stability, suitable flexibility, and 2.2-3.9 MPa tensile strength were observed. Formulations indicated antifungal efficacy against Candida albicans and Aspergillus fumigatus and cell viability >70% at different concentrations. Results of bioassay against Candida albicans exhibited prolonged in vitro release of 50-70% of ITZ for almost 55 days. The results suggested that the nanofibers could be considered suitable for prolonged delivery of the ITZ as an antifungal requiring frequent and long duration of administration.

Multi-Organs-on-Chips for Testing Small-Molecule Drugs: Challenges and Perspectives

Organ-on-a-chip technology has been used in testing small-molecule drugs for screening potential therapeutics and regulatory protocols. The technology is expected to boost the development of novel therapies and accelerate the discovery of drug combinations in the coming years. This has led to the development of multi-organ-on-a-chip (MOC) for recapitulating various organs involved in the drug-body interactions. In this review, we discuss the current MOCs used in screening small-molecule drugs and then focus on the dynamic process of drug absorption, distribution, metabolism, and excretion. We also address appropriate materials used for MOCs at low cost and scale-up capacity suitable for high-performance analysis of drugs and commercial high-throughput screening platforms.

Preparation of Nanofibers Mats Derived from Task-Specific Polymeric Ionic Liquid for Sensing and Catalytic Applications

Nanofibers mats derived from the task-specific functionalized polymeric ionic liquids based on homocysteine thiolactone are obtained by electrospinning them as blends with polyvinylpyrrolidone. The presence of this functional moiety allowed the post-functionalization of these mats through the aminolysis of the thiolactone ring in the presence of an amine by a thiol–alkene “click” reaction. Under controlled experimental conditions the modification can be performed introducing different functionalization and crosslinking of the electrospun fibers, while maintaining the nanostructure obtained by the electrospinning. Initial studies suggest that the nanofibers based on these functionalized polymeric ionic liquids can be used in both sensing and catalytic applications.

Weibull Modeling of Controlled Drug Release from Ag-PMA Nanosystems

Traditional pharmacotherapy suffers from multiple drawbacks that hamper patient treatment such as antibiotic resistances or low drug selectivity and toxicity during systemic applications. Some functional hybrid nanomaterials are designed to handle the drug release process under remote-control. More attention has recently been paid to synthetic polyelectrolytes for their intrinsic properties which allow them to rearrange into compact structures, ideal to be used as drug carriers or probes influencing biochemical processes. The presence of Ag nanoparticles (NPs) in the Poly methyl acrylate (PMA) matrix leads to an enhancement of drug release efficiency, even using a low-power laser whose wavelength is far from the Ag Surface Plasmon Resonance (SPR) peak. Further, compared to the colloids, the nanofiber-based drug delivery system has shown shorter response time and more precise control over the release rate. The efficiency and timing of involved drug release mechanisms has been estimated by the Weibull distribution function, whose parameters indicate that the release mechanism of nanofibers obeys Fick's first law while a non-Fickian character controlled by diffusion and relaxation of polymer chains occurs in the colloidal phase.

Fabrication of amphotericin B-loaded electrospun core-shell nanofibers as a novel dressing for superficial mycoses and cutaneous leishmaniasis

Amphotericin B (AmB) is an antifungal and antiparasitic agent that is the main drug used for the treatment of mycoses infections and leishmaniasis. However, its high toxicity and side effects are the main difficulties attributed to its application. In this study, to minimize its harmful effects, AmB-loaded core-shell nanofibers were fabricated, using polyvinyl alcohol, chitosan, and AmB as the core, and polyethylene oxide and gelatin as the shell-forming components. The nanofibers were characterized, using scanning electron microscopy, transmission electron microscopy, Fourier-transform infrared spectroscopy, tensile test, drug release, and MTT assay. The results showed that the prepared nanofibers were smooth and had a core-shell structure with almost no cytotoxicity against fibroblast cells and the release study suggested that the core-shell structure decreased the burst release. The disk diffusion assay revealed that the nanofibrous mats at different AmB concentrations exhibited significant activity against all the eight evaluated fungal species with the inhibition zones of 1.4-2.6 cm. The flow cytometry assay also showed that the prepared nanofibrous mat significantly killed Leishmania major promastigotes up to 84%. The obtained results indicated that this AmB-loaded nanofibrous system could be a suitable candidate for a topical drug delivery system for the treatment of both superficial mycoses and cutaneous leishmaniasis.

Electrospun PVP/PVA Nanofiber Mat as a Novel Potential Transdermal Drug-Delivery System for Buprenorphine: A Solution Needed for Pain Management

Over the past several decades, the formulation of novel nanofiber-based drug-delivery systems has been a frequent focus of scientists around the world. Aiming to introduce a novel nanofibrous transdermal drug-delivery system to treat pain, the nanofiber mats of buprenorphine-loaded poly (vinyl pyrrolidone) (Bup/PVP) and buprenorphine-loaded poly(vinyl alcohol)/poly(vinyl pyrrolidone) (Bup/PVP/PVA) were successfully fabricated by the electrospinning process for transdermal drug delivery. Similarly, PVP and PVP/PVA nanofibers were fabricated in the same conditions for comparison. The viscosity and electrical conductivity of all electrospinning solutions were measured, and nanofiber mats were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), Fourier transform infrared (FT-IR) spectroscopy and contact angle analysis. The conductivity of PVP and PVP/PVA solutions showed a considerable increase by the addition of buprenorphine due to the polarity of buprenorphine. SEM images showed a smooth, fine and porous nanofibrous structure without any adhesion or knot for all of the samples. The contact angle analysis showed the increased hydrophilicity and wettability of PVP/PVA and Bup/PVP/PVA nanofibers compared to PVP and Bup/PVP nanofibers which can be attributed to the addition of PVA. Attenuated total reflectance (ATR) FT-IR results confirmed that the electrospinning process did not affect the chemical integrity of the drug. For the modification of the drug release rate, the cross-linking of nanofiber mats was carried out using glutaraldehyde. Drug release measurements using high-performance liquid chromatography (HPLC) analysis demonstrated that Bup/PVP/PVA nanofibers exhibited better physical and chemical properties compared to Bup/PVP. Furthermore, the cross-linking of nanofibers led to an increase in drug release time. Thus, the novel buprenorphine-loaded nanofibers can be efficient biomaterial patches for transdermal delivery against pain improving carrier retention and providing a controlled release of the drug.

Fast Dissolution Electrospun Medicated Nanofibers for Effective Delivery of Poorly Water-Soluble Drugs

BACKGROUND

Electrospinning is developing rapidly from an earlier laboratory method into an industrial process. The clinical applications are approached in various ways through electrospun medicated nanofibers. The fast-dissolving oral drug delivery system (DDS) among them is one of the most promising routes in the near future for commercial applications.

METHODS

Related papers are investigated, including the latest research results, on electrospun nanofiber-based fast-dissolution DDSs.

RESULTS

Several relative topics have been concluded: 1) the development of electrospinning, ranging from 1-fluid blending to multi-fluid process and potential applications in the formation of medicated nanofibers involving poorly water-soluble drugs; 2) Selection of appropriate polymer matrices and drug carriers for filament formation; 3) Types of poorly water-soluble drugs ideal for fast oral delivery; 4) The methods for evaluating fast-dissolving nanofibers; 5) The mechanisms that promote the fast dissolution of poorly water-soluble drugs by electrospun nanofibers; 6) the important issues for further development of electrospun medicated nanofibers as oral fast-dissolving drug delivery systems. Conclusions & Perspectives: The unique properties of electrospun-medicated nanofibers can be used as oral fast dissolving DDSs of poorly water-soluble drugs. However, some significant issues need to be investigated, such as scalable productions and solid dosage form conversions.

Wound dressings as growth factor delivery platforms for chronic wound healing

Introduction: Years of tissue engineering research have clearly demonstrated the potential of integrating growth factors (GFs) into scaffolds for tissue regeneration, a concept that has recently been applied to wound dressings. The old concept of wound dressings that only take a passive role in wound healing has now been overtaken, and advanced dressings which can take an active part in wound healing, are of current research interest.Areas covered: In this review we will focus on the recent strategies for the delivery of GFs to wound sites with an emphasis on the different approaches used to achieve fine tuning of spatial and temporal concentrations to achieve therapeutic efficacy.Expert opinion: The use of GFs to accelerate wound healing and reduce scar formation is now considered a feasible therapeutic approach in patients with a high risk of infections and complications. The integration of micro - and nanotechnologies into wound dressings could be the key to overcome the inherent instability of GFs and offer adequate control over the release rate. Many investigations have led to encouraging outcomes in various in vitro and in vivo wound models, and it is expected that some of these technologies will satisfy clinical needs and will enter commercialization.

A Review on Ocular Novel Drug Delivery Systems of Antifungal Drugs: Functional Evaluation and Comparison of Conventional and Novel Dosage Forms

Ocular fungal infections affect more than one million people annually worldwide. They can lead to impaired vision or even complete blindness, so they should be treated immediately to prevent such consequences. Although topical administration has always been the most common route of ocular drug delivery owing to high patient acceptance, reduced side effects, and the possibility of self-administration, its limited ocular bioavailability poses a major challenge. As a result, attention has recently been drawn to the design and development of novel drug delivery systems (NDDS) that can overcome the challenges of conventional dosage forms. This research is the first to review and classify the studies which have designed and developed topical ocular NDDS with the aim to compare the performance and antifungal activity of these novel systems with conventional forms. According to the results, all studies seemed to confirm the superiority of NDDS over conventional forms in cases of released and permeated drug and antifungal activity. The NDDS were used specifically to improve ocular delivery by slowing down the release rate, increasing drug permeation, and subsequently increasing the antifungal effects of the active pharmaceutical ingredients. Hence, further studies on NDDS may aid the optimization of ocular drug delivery of antifungal drugs.

Effectiveness of Core-Shell Nanofibers Incorporating Amphotericin B by Solution Blow Spinning Against Leishmania and Candida Species

The aim of this study was to develop polymeric nanofibers for controlled administration of Amphotericin B (AmpB), using the solution centrifugation technique, characterizing its microstructural and physical properties, release rate, and activity against Leishmania and Candida species. The core-shell nanofibers incorporated with AmpB were synthesized by Solution Blow Spinning (SBS) and characterized by scanning electron microscopy (SEM), differential scanning calorimetry, X-Ray diffraction, and drug release assay. In vitro leishmanicidal and antifungal activity were also evaluated. Fibrous membranes with uniform morphology and smooth surfaces were produced. The intensity of the diffraction peaks becomes slightly more pronounced, assuming the increased crystallization in PLA/PEG at high AmpB loadings. Drug release occurred and the solutions with nanofibers to encourage greater incorporation of AmpB showed a higher concentration. In the results of the experiment with promastigotes, the wells treated with nanofibers containing concentrations of AmpB at 0.25, 0.5, and 1%, did not have any viable cells, similar to the positive control. Various concentrations of AmpB improved the inhibition of fungal growth. The delivery system based on PLA/PEG nanofibers was properly developed for AmpB, presenting a controlled release and a successful encapsulation, as well as antifungal and antileishmanial activity.

Electrospun nanofibers: A nanotechnological approach for drug delivery and dissolution optimization in poorly water-soluble drugs

Electrospinning is a novel and sophisticated technique for the production of nanofibers with high surface area, extreme porous structure, small pore size, and surface morphologies that make them suitable for biomedical and bioengineering applications, which can provide solutions to current drug delivery issues of poorly water-soluble drugs. Electrospun nanofibers can be obtained through different methods asides from the conventional one, such as coaxial, multi-jet, side by side, emulsion, and melt electrospinning. In general, the application of an electric potential to a polymer solution causes a charged liquid jet that moves downfield to an oppositely charged collector, where the nanofibers are deposited. Plenty of polymers that differ in their origin, degradation character and water affinity are used during the process. Physicochemical properties of the drug, polymer(s), and solvent systems need to be addressed to guarantee successful manufacturing. Therefore, this review summarizes the recent progress in electrospun nanofibers for their use as a nanotechnological tool for dissolution optimization and drug delivery systems for poorly water-soluble drugs.

Preparation and Characterization of Fenofibrate-Loaded PVP Electrospun Microfibrous Sheets

Fenofibrate-loaded electrospun microfibrous sheets were prepared in an attempt to enhance the dissolution of the poorly soluble antihyperlipidemic agent and to improve its bioavailability. Physicochemical changes that appeared during the electrospinning process were monitored using a wide array of solid-state characterization techniques, including attenuated total reflectance Fourier-transformed infrared spectroscopy and positron annihilation lifetime spectroscopy, while fiber morphology was monitored via scanning electron microscopy. Dissolution studies carried out both in 0.025 M sodium dodecyl sulfate and in water revealed an immediate release of the active agent, with an approximately 40-fold release rate enhancement in water when compared to the micronized active agent. The dramatic increase in dissolution was attributed partially to the amorphous form of the originally crystalline active agent and the rapid disintegration of the electrospun microfibrous sheet due to its high surface area and porosity. The obtained results could pave the way for a formulation of the frequently used antihyperlipidemic agent with increased bioavailability.

Glucantime-loaded electrospun core-shell nanofibers composed of poly(ethylene oxide)/gelatin-poly(vinyl alcohol)/chitosan as dressing for cutaneous leishmaniasis

Leishmaniasis, one of the main concerns of the World Health Organization, is a parasitic disease caused by Leishmania species. The main objective of this study was to prepare a topical drug delivery system that can deliver glucantime to the site of cutaneous Leishmania wounds. Using the electrospinning method, a core-shell nanofibrous mat composed of macromolecules including polyethylene oxide, gelatin, poly (vinyl alcohol) and chitosan was prepared. The prepared nanofibers were characterized by scanning electron microscopy (SEM), transmission electron microscopy, Fourier transform infrared spectroscopy (FT-IR), tensile test and in vitro drug release test. The anti-Leishmania activities of drug-loaded nanofibers against Leishmania promastigotes and its cytotoxicity on fibroblasts were determined respectively by flow-cytometry and indirect MTT methods. Results of morphological studies showed that uniform nanofibers were prepared without any bead with average diameter of 404 nm. The TEM investigation confirmed the core-shell structure of the fibers. The in-vitro drug release assay was executed using Franz diffusion cell, which indicted 84% of glucantime was released during the first 9 h. The results indicated that 4 and 6 cm² of nanofibers mat were significantly killed promatigotes up to 78%. Moreover, the MTT assay also showed that the fabricated nanofibers do not possess any cytotoxicity towards fibroblast cells.

Influence of Aqueous Solubility-Enhancing Excipients on the Microstructural Characteristics of Furosemide-Loaded Electrospun Nanofibers

Electrospun nanofibers were prepared from furosemide-containing hydroxypropyl cellulose and poly(vinylpyrrolidone) aqueous solutions using different solubility enhancers. In one case, a solubilizer, triethanolamine, was applied, while in the other case a pH-modifier, sodium hydroxide, was applied. Scanning electron microscopy (SEM) was carried out for morphological characterization of the fibers. The SEM images indicated similar mean diameter size of the two fibrous formulations. However, in contrast to the NaOH-containing fibers of normal diameter distribution, the triethanolamine-containing fibers showed approximately normal diameter distribution, possibly due to their plasticizing effect and the consequent slightly ribbon-like morphology. Attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), powder X-ray diffraction (XRD) and positron annihilation lifetime spectroscopy (PALS) were applied for microstructural characterization. The FTIR measurements confirmed that furosemide salt was formed in both cases. There was no sign of any crystallinity based on the XRD measurements. However, the PALS highlighted the differences in the average o-Ps lifetime values and distributions of the furosemide-loaded fibrous formulations. The two types of electrospun nanofibrous formulations containing amorphous furosemide salt showed similar macrostructures but different microstructural characteristics depending on the type of solubility enhancers, which lead to altered storage stability.

Double stimuli-responsive cellulose nanocrystals reinforced electrospun PHBV composites membrane for intelligent drug release

Double stimuli-responsive functionalized cellulose nanocrystal-poly[2-(dimethylamino)ethyl methacrylate] (CNC-g-PDMAEMA) reinforced poly(3-hydroxybutyrate-co-3-hydroxy valerate) (PHBV) electrospun composite membranes were explored as drug delivery vehicles using tetracycline hydrochloride (TH) as a model drug. It was found that rigid CNC-g-PDMAEMA nanoparticles enhanced thermal, crystallization and hydrophilic properties of PHBV. Moreover, great improvements in fiber diameter uniformity, crystallization ability and maximum decomposition temperature (T_max) could be achieved at 6 wt% CNC-g-PDMAEMA. Furthermore, by introducing stimuli-responsive CNC-g-PDMAEMA nanofillers, intelligent and long-term sustained release behavior of composite membranes could be achieved. The releasing mechanism of composite membranes based on zero order, first order, Higuchi and Korsmeyere-Peppas mathematical models was clearly demonstrated, giving effective technical guidance for practical drug delivery systems.

Crosslinked Hyaluronan Electrospun Nanofibers for Ferulic Acid Ocular Delivery

Electrospun nanofibers are gaining interest as ocular drug delivery platforms that may adapt to the eye surface and provide sustained release. The aim of this work was to design an innovative ophthalmic insert composed of hyaluronan (HA) nanofibers for the dual delivery of an antioxidant (ferulic acid, FA) and an antimicrobial peptide (ε-polylysine, ε-PL). Polyvinylpyrrolidone (PVP) was added to facilitate the electrospinning process. Fibers with diameters of approx. 100 nm were obtained with PVP 5%-HA 0.8% w/v and PVP 10%-HA 0.5% w/v mixtures in ethanol:water 4:6 v/v. An increase in PVP concentration to 20% w/v in both presence and absence of HA rendered fibers of approx. 1 µm. PVP 5%-HA 0.8% w/v fibers were loaded with 83.3 ± 14.0 µg FA per mg. After nanofibers crosslinking with ε-PL, blank and FA-loaded inserts showed a mean thickness of 270 ± 21 µm and 273 ± 41 µm, respectively. Blank and FA-loaded inserts completely released ε-PL within 30 min under sink conditions, whereas FA-loaded inserts released the antioxidant within 20 min. Both blank and FA-loaded inserts were challenged against Pseudomonas aeruginosa and Staphylococcus aureus, demonstrating their efficacy against relevant microbial species.

Electrospun nanofibers: a promising horizon toward the detection and treatment of cancer

Due to the increase in the number of cancer patients, because of environmental parameters, high stress, low immunity, etc., there is an urgent need to develop cost-effective sensors for early targeted detection of cancerous cells with adequate selectivity and efficiency. Early disease diagnosis is important, as it is necessary to start treatments before disease progression. On the other hand, we need new, more efficient cancer treatment approaches with minimized side effects, more biocompatibility, and easy disposal. Nanobiotechnology is a field that can assist in developing new diagnostic and treatment approaches, specifically in fatal cancers. Herein, a study on the different applications of nanofibers in cancer detection as well as its treatment has been done. Here, a very brief survey on the main structure of biosensors and their different categories has been conducted and will precede the discussion of the study to serve as a reference and guide the reader's understanding.

Electrospun Nanofibers as Carriers of Microorganisms, Stem Cells, Proteins, and Nucleic Acids in Therapeutic and Other Applications

Electrospinning is a technique that uses polymer solutions and strong electric fields to produce nano-sized fibers that have wide-ranging applications. We present here an overview of the use of electrospinning to incorporate biological products into nanofibers, including microorganisms, cells, proteins, and nucleic acids. Although the conditions used during electrospinning limit the already problematic viability/stability of such biological products, their effective incorporation into nanofibers has been shown to be feasible. Synthetic polymers have been more frequently applied to make nanofibers than natural polymers. Polymer blends are commonly used to achieve favorable physical properties of nanofibers. The majority of nanofibers that contain biological product have been designed for therapeutic applications. The incorporation of these biological products into nanofibers can promote their stability or viability, and also allow their delivery to a desired tissue or organ. Other applications include plant protection in agriculture, fermentation in the food industry, biocatalytic environmental remediation, and biosensing. Live cells that have been incorporated into nanofibers include bacteria and fungi. Nanofibers have served as scaffolds for stem cells seeded on a surface, to enable their delivery and application in tissue regeneration and wound healing. Viruses incorporated into nanofibers have been used in gene delivery, as well as in therapies against bacterial infections and cancers. Proteins (hormones, growth factors, and enzymes) and nucleic acids (DNA and RNA) have been incorporated into nanofibers, mainly to treat diseases and enhance their stability. To summarize, incorporation of biological products into nanofibers has numerous advantages, such as providing protection and facilitating controlled delivery from a solid form with a large surface area. Future studies should address the challenge of transferring nanofibers with biological products into practical and industrial use.

Rapid Release Polymeric Fibers for Inhibition of Porphyromonas gingivalis Adherence to Streptococcus gordonii

Active agents targeting key bacterial interactions that initiate biofilm formation in the oral cavity, may alter periodontitis progression; however, to date, specifically-targeted prophylactic and treatment strategies have been limited. Previously we developed a peptide, BAR (SspB Adherence Region), that inhibits oral P. gingivalis/S. gordonii biofilm formation in vitro and in vivo, and BAR nanoparticles that increase BAR effectiveness via multivalency and prolonged delivery. However, limited BAR loading and nanoparticle retention in the oral cavity can result in inadequate release and efficaciousness. Given this, an effective delivery platform that can release concentrations of BAR suitable for twice-daily applications, may offer an alternative that enhances loading, ease of administration, and retention in the oral cavity. With this in mind, the study objectives were to develop and characterize a rapid-release platform, composed of polymeric electrospun fibers (EFs) that encapsulate BAR, and to evaluate fiber safety and functionality against P. gingivalis/S. gordonii biofilms in vitro. Poly(lactic-co-glycolic acid) (PLGA), poly(L-lactic acid) (PLLA), and polycaprolactone (PCL) were electrospun alone or blended with polyethylene oxide (PEO), to provide high BAR loading and rapid-release. The most promising formulation, 10:90 PLGA:PEO EFs, provided 95% BAR release after 4 h, dose-dependent inhibition of biofilm formation (IC50 = 1.3 μM), disruption of established dual-species biofilms (IC50 = 2 μM), and maintained high cell viability. These results suggest that BAR-incorporated EFs may provide a safe and specifically-targeted rapid-release platform to inhibit and disrupt dual-species biofilms, that we envision may be applied twice-daily to exert prophylactic effect in the oral cavity.

Preformulation Study of Electrospun Haemanthamine-Loaded Amphiphilic Nanofibers Intended for a Solid Template for Self-Assembled Liposomes

Haemanthamine (HAE) has been proven as a potential anticancer agent. However, the therapeutic use of this plant-origin alkaloid to date is limited due to the chemical instability and poorly water-soluble characteristics of the agent. To overcome these challenges, we developed novel amphiphilic electrospun nanofibers (NFs) loaded with HAE, phosphatidylcholine (PC) and polyvinylpyrrolidone (PVP), and intended for a stabilizing platform (template) of self-assembled liposomes of the active agent. The NFs were fabricated with a solvent-based electrospinning method. The chemical structure of HAE and the geometric properties, molecular interactions and physical solid-state properties of the NFs were investigated using nuclear magnetic resonance (NMR) spectroscopy, scanning electron microscopy (SEM), photon correlation spectroscopy (PCS), Fourier transform infrared (FTIR) spectroscopy, X-ray powder diffraction (XRPD) and differential scanning calorimetry (DSC), respectively. An in-house dialysis-based dissolution method was used to investigate the drug release in vitro. The HAE-loaded fibers showed a nanoscale size ranging from 197 nm to 534 nm. The liposomes with a diameter between 63 nm and 401 nm were spontaneously formed as the NFs were exposed to water. HAE dispersed inside liposomes showed a tri-modal dissolution behavior. In conclusion, the present amphiphilic NFs loaded with HAE are an alternative approach for the formulation of a liposomal drug delivery system and stabilization of the liposomes of the present alkaloid.

Comparison of Traditional and Ultrasound-Enhanced Electrospinning in Fabricating Nanofibrous Drug Delivery Systems

We investigated nozzleless ultrasound-enhanced electrospinning (USES) as means to generate nanofibrous drug delivery systems (DDSs) for pharmaceutical and biomedical applications. Traditional electrospinning (TES) equipped with a conventional spinneret was used as a reference method. High-molecular polyethylene oxide (PEO) and chitosan were used as carrier polymers and theophylline anhydrate as a water-soluble model drug. The nanofibers were electrospun with the diluted mixture (7:3) of aqueous acetic acid (90% v/v) and formic acid solution (90% v/v) (with a total solid content of 3% w/v). The fiber diameter and morphology of the nanofibrous DDSs were modulated by varying ultrasonic parameters in the USES process (i.e., frequency, pulse repetition frequency and cycles per pulse). We found that the USES technology produced nanofibers with higher fiber diameter (402 ± 127 nm) than TES (77 ± 21 nm). An increase of a burst count in USES increased the fiber diameter (555 ± 265 nm) and the variation in fiber size. The slight-to-moderate changes in a solid state (crystallinity) were detected when compared the nanofibers generated by TES and USES. In conclusion, USES provides a promising alternative for aqueous-based fabrication of nanofibrous DDSs for pharmaceutical and biomedical applications.

Quasi-Dynamic Dissolution of Electrospun Polymeric Nanofibers Loaded with Piroxicam

We investigated and monitored in situ the wetting and dissolution properties of polymeric nanofibers and determined the solid-state of a drug during dissolution. Piroxicam (PRX) was used as a low-dose and poorly-soluble model drug, and hydroxypropyl methylcellulose (HPMC) and polydextrose (PD) were used as carrier polymers for electrospinning (ES). The initial-stage dissolution of the nanofibers was monitored in situ with three-dimensional white light microscopic interferometry (SWLI) and high-resolution optical microscopy. The physical solid-state characterization of nanofibers was performed with Raman spectroscopy, X-ray powder diffraction (XRPD), and scanning electron microscopy (SEM). We showed that PRX recrystallizes in a microcrystalline form immediately after wetting of nanofibers, which could lead to enhanced dissolution of drug. Initiation of crystal formation was detected by SWLI, indicating: (1) that PRX was partially released from the nanofibers, and (2) that the solid-state form of PRX changed from amorphous to crystalline. The amount, shape, and size of the PRX crystals depended on the carrier polymer used in the nanofibers and dissolution media (pH). In conclusion, the present nanofibers loaded with PRX exhibit a quasi-dynamic dissolution via recrystallization. SWLI enables a rapid, non-contacting, and non-destructive method for in situ monitoring the early-stage dissolution of nanofibers and regional mapping of crystalline changes (re-crystallization) during wetting. Such analysis is crucial because the wetting and dissolution of nanofibers can greatly influence the performance of nanofibrous drug delivery systems in pharmaceutical and biomedical applications.

The Effects of Vinegar Processing on the Changes in the Physical Properties of Frankincense Related to the Absorption of the Main Boswellic Acids

Boswellic acids (BAs), as the main components of frankincense, exhibit notable anti-inflammatory properties. However, their pharmaceutical development has been severely limited by their poor oral bioavailability. Traditional Chinese medicinal processing, called Pao Zhi, is believed to improve bioavailability, yet the mechanism is still completely unclear. Previous research suggested that the bioavailability of a drug can be influenced by physical properties. This paper was designed to investigate the physical properties of frankincense and processed frankincense, including the surface morphology, particle size, polydispersity index (PDI), zeta potential (ZP), specific surface area, porosity, and viscosity. The differences in the intestinal absorption characteristics and equilibrium solubilities between frankincense and processed frankincense were determined by an ultra-high-performance liquid chromatography coupled with a triple quadrupole electrospray tandem mass spectrometry (UHPLC-TQ-MS) analysis method. The results showed that vinegar processing can alter the surface morphology, decrease the particle size and PDI, raise the absolute values of the ZP, specific surface area and porosity, and drop the viscosity of frankincense. Meanwhile, the rates of absorption and dissolution of the main BAs were increased after the processing of frankincense. The present study proves that the physical properties were changed after processing, in which case the bioavailability of frankincense was enhanced.

Polyvinylpyrrolidone/cellulose acetate electrospun composite nanofibres loaded by glycerine and garlic extract with in vitro antibacterial activity and release behaviour test

The antibacterial activity of garlic (Allium sativum) is believed to be due to its organosulfur compounds, which can supposedly be used further in biomedical applications. This paper reported the use of electrospinning to encapsulate a garlic extract and glycerine in nanofibrous mats. Polyvinylpyrrolidone (PVP) and cellulose acetate (CA) were the building blocks of the composite fibres that served as the hydrophilic matrix to encapsulate the garlic extract with glycerine added mainly to improve the mechanical characteristics of the composite fibres. The combinations of the fibres were PVP/CA, PVP/CA/garlic, PVP/CA/glycerine, and PVP/CA/glycerine/garlic. The characterizations included the morphology, chemical interaction, swelling degree, weight loss, acidity level, wettability, in vitro antibacterial test, and release behaviour test. The composite nanofibrous mats were uniform, bead-free with a size ranging from 350 nm to 900 nm. The Fourier-transform infrared spectra proved the presence of the garlic extract and glycerine in the fibres. The swelling degree test showed that the fibrous mats generally did have maximum swelling degrees above 100% except for the PVP/CA fibrous mat, whose maximum value was not achieved within 48 hours. The fibrous mat with glycerine showed generally larger weight loss compared to the fibrous mats without glycerine. The result of the contact angle measurement proved that the composite fibres are all hydrophilic with the PVP/CA/glycerine/garlic fibres being the least hydrophilic. The pH level of the fibre mats was from 3.7 to 4.0 due to the use of acetic acid. The Young's modulus and ultimate tensile strength of the mats were significantly reduced due to the presence of glycerine. The encapsulation of the garlic extract in the fibres did not eliminate the antibacterial activity of the garlic extract, as proven in the in vitro antibacterial test. The release of the garlic extract from the composite PVP/CA/glycerine/garlic fibres was found to be the largest due to the large diameter of the fibres, while the blend of PVP with CA successfully reduced the rate of release due to the insolubility of CA. We successfully encapsulated the garlic extract and glycerine in the PVP/CA nanofibrous mats with antibacterial activity.