Electrospun biphasic drug release polyvinylpyrrolidone/ethyl cellulose core/sheath nanofibers

Rapid fabrication of polyoxometalate-enhanced photo responsive films from ethyl cellulose (EC) and polyvinylpyrrolidone (PVP)

Ethyl cellulose (EC), polyvinylpyrrolidone (PVP), and phosphomolybdic acid (PMoA) were the components of a new photochromic hybrid film composed of heteropoly acids (abbreviated EC-PVP/PMoA), created by solvent evaporation. The EC-PVP/PMoA mechanism, visible light photochromic behaviors, and microstructure were closely studied by transmission electron microscopy (TEM), atomic force microscopy (AFM), ultraviolet-visible (UV-visible) spectroscopy, X-ray photo electronics (XPS), and Fourier transmission infrared spectroscopy (FTIR). FTIR spectra show that neither the core structures of EC, PVP, nor the Keggin structure of PMoA in the EC-PVP/PMoA composite hybrid film were damaged during fabrication. In the presence of oxygen, the yellowish transparent hybrid film exhibited reversible photochromism and significant photochromic reactivity, becoming blue in the presence of visible light. Upon heating the film at 90 °C for 1 h its photoresponsive properties were enhanced, making the blue color more vibrant and stable due to polyethylene glycol (PEG). The XPS spectra demonstrated a proton transfer procedure during the photochromic process, and the presence of Mo+5 species indicated a photoreduction interaction between the PMoA particles and the EC-PVP matrix. To the best of our knowledge, this is the first EC-PVP combined hybrid film with POMs with promising prospects for solar UV detection and smart glass windows applications.

A new strategy for the treatment of middle ear infection using ciprofloxacin/amoxicillin-loaded ethyl cellulose/polyhydroxybutyrate nanofibers

A middle ear infection occurs due to the presence of several microorganisms behind the eardrum (tympanic membrane) and is very challenging to treat due to its unique location and requires a well-designed treatment. If not treated properly, the infection can result in severe symptoms and unavoidable side effects. In this study, excellent biocompatible ethyl cellulose (EC) and biodegradable polyhydroxybutyrate (PHB) biopolymer were used to fabricate drug-loaded nanofiber scaffolds using an electrospinning technique to overcome antibiotic overdose and insufficient efficacy of drug release during treatment. PHB polymer was produced from Halomonas sp., and the purity of PHB was found to around be 90 %. Additionally, ciprofloxacin (CIP) and amoxicillin (AMX) are highly preferable since both drugs are highly effective against gram-negative and gram-positive bacteria to treat several infections. Obtained smooth nanofibers were between 116.24 and 171.82 nm in diameter and the addition of PHB polymer and antibiotics improved the morphology of the nanofiber scaffolds. Thermal properties of the nanofiber scaffolds were tested and the highest Tg temperature resulted at 229 °C. The mechanical properties of the scaffolds were tested, and the highest tensile strength resulted in 4.65 ± 6.33 MPa. Also, drug-loaded scaffolds were treated against the most common microorganisms that cause the infection, such as S.aureus, E.coli, and P.aeruginosa, and resulted in inhibition zones between 10 and 21 mm. MTT assay was performed by culturing human adipose-derived mesenchymal stem cells (hAD MSCs) on the scaffolds. The morphology of the hAD MSCs' attachment was tested with SEM analysis and hAD MSCs were able to attach, spread, and live on each scaffold even on the day of 7. The cumulative drug release kinetics of CIP and AMX from drug-loaded scaffolds were analysed in phosphate-buffered saline (pH: 7.4) within different time intervals of up to 14 days using a UV spectrophotometer. Furthermore, the drug release showed that the First-Order and Korsmeyer-Peppas models were the most suitable kinetic models. Animal testing was performed on SD rats, matrix and collagen deposition occurred on days 5 and 10, which were observed using Hematoxylin-eosin and Masson's trichrome staining. At the highest drug concentration, a better repair effect was observed. Results were promising and showed potential for novel treatment.

Exploring temperature-responsive drug delivery with biocompatible fatty acids as phase change materials in ethyl cellulose nanofibers

This study introduces a novel temperature-responsive drug delivery system using ethyl cellulose (EC) nanofibers encapsulating a eutectic mixture of lauric acid/stearic acid (LA/SA) as phase change materials (PCMs) and Rhodamine B (RhB) as a model drug. Employing blend electrospinning, the nanofibers achieved controlled drug release responsive to temperature changes. The peak shift of the carbonyl group in FTIR analysis confirmed drug-polymer compatibility, while the absence of RhB peaks in the XRD and DSC assessments revealed RhB's amorphous distribution within the fibers. Our findings demonstrate that RhB release is dependent on its loading, with a slow initial release (<2 %) for 1 % and 5 % RhB loadings and a burst release (~12 %) for 10 % loading. Notably, the release rate was tunable at 37 °C by adjusting LA/SA concentration. The optimal LA/SA loading for temperature-responsive release is identified as 10 %. Over 240 h, there is a 32 % increase in RhB release at 37 °C, and an additional 8 % increase at 40 °C, compared to 25 °C. This research illustrates the potential of PCM-integrated nanofibers in smart drug delivery, particularly for chemotherapy, antibiotics, and anti-inflammatory drugs, showcasing an innovative approach to improving therapeutic efficiency while reducing side effects.

Hydrophilic and hydrophobic drug release from core (polyvinylpyrrolidone)-sheath (ethyl cellulose) pressure-spun fibers

A core-sheath structure is one of the methods developed to overcome the challenges often faced when using monolithic fibers for drug delivery. In this study, fibers based on polyvinylpyrrolidone (core) and ethyl cellulose (sheath) were successfully produced using a novel core-sheath pressure-spinning process. For comparison, these two polymers were also processed into as blend fibers. All samples were then investigated for their performances in releasing water-soluble ampicillin (AMP) and poorly water-soluble ibuprofen (IBU) model drugs. Scanning electron,digital and confocal microscopy confirmed that fibers with a core-sheath structure were successfully made. Fourier transform infrared spectroscopy showed the success of the pressure-spinning technique in encapsulating AMP/IBU in all fiber samples. Compared to blend fibers, the core-sheath fibers had better performance in encapsulating both water-soluble and poorly water-soluble drugs. Moreover, the core-sheath structure was able to reduce the initial burst release and provided a better sustained release profile than the blend fiber analog. In conclusion, the pressure-spinning method was capable of producing core-sheath and blend fibers that could be used for the loading of either hydrophilic or hydrophobic drugs for controlled drug delivery systems.

Recent advances in cellulose-based sustainable materials for wastewater treatment: An overview

Water pollution presents a significant challenge, impacting ecosystems and human health. The necessity for solutions to address water pollution arises from the critical need to preserve and protect the quality of water resources. Effective solutions are crucial to safeguarding ecosystems, human health, and ensuring sustainable access to clean water for current and future generations. Generally, cellulose and its derivatives are considered potential substrates for wastewater treatment. The various cellulose processing methods including acid, alkali, organic & inorganic components treatment, chemical treatment and spinning methods are highlighted. Additionally, we reviewed effective use of the cellulose derivatives (CD), including cellulose nanocrystals (CNCs), cellulose nano-fibrils (CNFs), CNPs, and bacterial nano-cellulose (BNC) on waste water (WW) treatment. The various cellulose processing methods, including spinning, mechanical, chemical, and biological approaches are also highlighted. Additionally, cellulose-based materials, including adsorbents, membranes and hydrogels are critically discussed. The review also highlighted the mechanism of adsorption, kinetics, thermodynamics, and sorption isotherm studies of adsorbents. The review concluded that the cellulose-derived materials are effective substrates for removing heavy metals, dyes, pathogenic microorganisms, and other pollutants from WW. Similarly, cellulose based materials are used for flocculants and water filtration membranes. Cellulose composites are widely used in the separation of oil and water emulsions as well as in removing dyes from wastewater. Cellulose's natural hydrophilicity makes it easier for it to interact with water molecules, making it appropriate for use in water treatment processes. Furthermore, the materials derived from cellulose have wider application in WW treatment due to their inexhaustible sources, low energy consumption, cost-effectiveness, sustainability, and renewable nature.

Development of gallic acid-loaded ethylcellulose fibers as a potential wound dressing material

In this study, novel fibers were designed based on ethylcellulose (EC), loaded with different concentrations of gallic acid (GA) using the electrospinning technique, in order to investigate the potential of these materials as wound dressings. The chemical structure and morphology, along with the antimicrobial and biocompatibility tests of the EC_GA fibers were investigated. To observe the chemical interactions between the components, fourier transform infrared spectroscopy (FTIR) was used. The morphological analyzes were performed using scanning electron microscope (SEM). The uniaxial tensile test machine was used to obtain mechanical performance of the fibers. MTT assay was applied to get the biocompatibility properties of the fibers and antimicrobial test was applied to obtain the antimicrobial activity of the fibers. Based on the obtained results, the highest viability value of 67.4 % was obtained for 10%EC_100GA on the third day of incubation, demonstrating that with the addition of a higher concentration of GA, the cell viability increases. The antimicrobial tests, evaluated against Staphylococcus (S.) aureus, Escherichia (E.) coli, Pseudomonas (Ps.) aeruginosa and Candida (C.) albicans, showed a >90 % microbial reduction capacity correlated with a logarithmic reduction ranging from 0.63 to 1, for 10%EC_100 GA. In vitro release tests of GA from the fibers showed that GA was totally released from 10%EC_100 GA fibers after 2880 min, demonstrating a controlled release profile. These findings demonstrated that EC_GA fibers may be suitable for application in biomedical fields such as wound dressing materials. However, further studies should be performed to increase the biocompatibility properties of the fibers.

Electrospun Nanofibers: Shaping the Future of Controlled and Responsive Drug Delivery

Electrospun nanofibers for drug delivery systems (DDS) introduce a revolutionary means of administering pharmaceuticals, holding promise for both improved drug efficacy and reduced side effects. These biopolymer nanofiber membranes, distinguished by their high surface area-to-volume ratio, biocompatibility, and biodegradability, are ideally suited for pharmaceutical and biomedical applications. One of their standout attributes is the capability to offer the controlled release of the active pharmaceutical ingredient (API), allowing custom-tailored release profiles to address specific diseases and administration routes. Moreover, stimuli-responsive electrospun DDS can adapt to conditions at the drug target, enhancing the precision and selectivity of drug delivery. Such localized API delivery paves the way for superior therapeutic efficiency while diminishing the risk of side effects and systemic toxicity. Electrospun nanofibers can foster better patient compliance and enhanced clinical outcomes by amplifying the therapeutic efficiency of routinely prescribed medications. This review delves into the design principles and techniques central to achieving controlled API release using electrospun membranes. The advanced drug release mechanisms of electrospun DDS highlighted in this review illustrate their versatility and potential to improve the efficacy of medical treatments.

Multi-material electrospinning: from methods to biomedical applications

Electrospinning as a versatile, simple, and cost-effective method to engineer a variety of micro or nanofibrous materials, has contributed to significant developments in the biomedical field. However, the traditional electrospinning of single material only can produce homogeneous fibrous assemblies with limited functional properties, which oftentimes fails to meet the ever-increasing requirements of biomedical applications. Thus, multi-material electrospinning referring to engineering two or more kinds of materials, has been recently developed to enable the fabrication of diversified complex fibrous structures with advanced performance for greatly promoting biomedical development. This review firstly gives an overview of multi-material electrospinning modalities, with a highlight on their features and accessibility for constructing different complex fibrous structures. A perspective of how multi-material electrospinning opens up new opportunities for specific biomedical applications, i.e., tissue engineering and drug delivery, is also offered.

Dual-Step Controlled Release of Berberine Hydrochloride from the Trans-Scale Hybrids of Nanofibers and Microparticles

In this nano era, nanomaterials and nanostructures are popular in developing novel functional materials. However, the combinations of materials at micro and macro scales can open new routes for developing novel trans-scale products with improved or even new functional performances. In this work, a brand-new hybrid, containing both nanofibers and microparticles, was fabricated using a sequential electrohydrodynamic atomization (EHDA) process. Firstly, the microparticles loaded with drug (berberine hydrochloride, BH) molecules in the cellulose acetate (CA) were fabricated using a solution electrospraying process. Later, these microparticles were suspended into a co-dissolved solution that contained BH and a hydrophilic polymer (polypyrrolidone, PVP) and were co-electrospun into the nanofiber/microparticle hybrids. The EHDA processes were recorded, and the resultant trans-scale products showed a typical hybrid topography, with microparticles distributed all over the nanofibers, which was demonstrated by SEM assessments. FTIR and XRD demonstrated that the components within the hybrids were presented in an amorphous state and had fine compatibility with each other. In vitro dissolution tests verified that the hybrids were able to provide the designed dual-step drug release profiles, a combination of the fast release step of BH from the hydrophilic PVP nanofibers through an erosion mechanism and the sustained release step of BH from the insoluble CA microparticles via a typical Fickian diffusion mechanism. The present protocols pave a new way for developing trans-scale functional materials.

Fabrication of hierarchical porous ethyl cellulose fibrous membrane by electro-centrifugal spinning for drug delivery systems with excellent integrated properties

Drug delivery systems (DDSs) based on micro-and nano- fibrous membrane have been developed for decades, in which great attention has been focused on achieving controlled drug release. However, the study on the integrated performance of these drug-loaded membranes in the use of in-vitro drug delivery dressing is lacking, as clinical medication also needs consideration from the perspectives of wound safety and patient convenience. Herein, a trilayered hierarchical porous ethyl cellulose (EC) fibrous membrane based DDS (EC-DDS) was developed by electro-centrifugal spinning. Significantly, the hierarchical porous structure of the EC-DDSs with high specific surface area (34.3 m²g^-1) and abundant long-regulative micro-and nano- channels demonstrated its merits in improving the hydrophobicity (long-term splash resistance (CA > 130°) and prolonging the drug release (the release time of ~80 % tetracycline hydrochloride (TCH) prolonged from 10 min to 24 h). Meanwhile, the trilayered EC-DDS also revealed excellent biocompatibility, antibacterial activity, air permeability, moisture permeability, water absorption capacity, mechanical strength, and flexibility. With these excellent integrated features, the EC-DDS could prevent external fluids, avoid infection, and provide comfort. Furthermore, this work also provides a new guide for the high-efficiency fabrication of porous fibrous membranes.

Biphasic drug release from electrospun structures

INTRODUCTION

Biphasic release, as a special drug-modified release profile that combines immediate and sustained release, allows fast therapeutic action and retains blood drug concentration for long periods. Electrospun nanofibers, particularly those with complex nanostructures produced by multi-fluid electrospinning processes, are potential novel biphasic drug delivery systems (DDSs).

AREAS COVERED

This review summarizes the most recent developments in electrospinning and related structures. In this review, the role of electrospun nanostructures in biphasic drug release was comprehensively explored. These electrospun nanostructures include monolithic nanofibers obtained through single-fluid blending electrospinning, core-shell and Janus nanostructures prepared via bifluid electrospinning, three-compartment nanostructures obtained via trifluid electrospinning, nanofibrous assemblies obtained through the layer-by-layer deposition of nanofibers, and the combined structure of electrospun nanofiber mats with casting films. The strategies and mechanisms through which complex structures facilitate biphasic release were analyzed.

EXPERT OPINION

Electrospun structures can provide many strategies for the development of biphasic drug release DDSs. However, many issues such as the scale-up productions of complex nanostructures, the in vivo verification of the biphasic release effects, keeping pace with the developments of multi-fluid electrospinning, drawing support from the state-of-the-art pharmaceutical excipients, and the combination with traditional pharmaceutical methods need to be addressed for real applications.

Silk Fibroin as an Efficient Biomaterial for Drug Delivery, Gene Therapy, and Wound Healing

Silk fibroin (SF), an organic material obtained from the cocoons of a silkworm Bombyx mori, is used in several applications and has a proven track record in biomedicine owing to its superior compatibility with the human body, superb mechanical characteristics, and its controllable propensity to decay. Due to its robust biocompatibility, less immunogenic, non-toxic, non-carcinogenic, and biodegradable properties, it has been widely used in biological and biomedical fields, including wound healing. The key strategies for building diverse SF-based drug delivery systems are discussed in this review, as well as the most recent ways for developing functionalized SF for controlled or redirected medicines, gene therapy, and wound healing. Understanding the features of SF and the various ways to manipulate its physicochemical and mechanical properties enables the development of more effective drug delivery devices. Drugs are encapsulated in SF-based drug delivery systems to extend their shelf life and control their release, allowing them to travel further across the bloodstream and thus extend their range of operation. Furthermore, due to their tunable properties, SF-based drug delivery systems open up new possibilities for drug delivery, gene therapy, and wound healing.

Overexpression of VEGF in dermal fibroblast cells accelerates the angiogenesis and wound healing function: in vitro and in vivo studies

Fibroblasts are the main cells of connective tissue and have pivotal roles in the proliferative and maturation phases of wound healing. These cells can secrete various cytokines, growth factors, and collagen. Vascular endothelial growth factor (VEGF) is a unique factor in the migration process of fibroblast cells through induces wound healing cascade components such as angiogenesis, collagen deposition, and epithelialization. This study aimed to create VEGF₁₆₅ overexpressing fibroblast cells to evaluate angiogenesis function in wound healing. In vitro, a novel recombinant expression vector, pcDNA3.1(-)-VEGF, was produced and transfected into the fibroblast cells. Following selecting fibroblast cells with hygromycin, recombinant cells were investigated in terms of VEGF expression by quantifying and qualifying methods. Mechanical, physical, and survival properties of polyurethane-cellulose acetate (PU-CA) scaffold were investigated. Finally, in vivo, the angiogenic potential was evaluated in four groups containing control, PU-CA, PU-CA with fibroblast cells, and VEGF-expressing cells on days 0, 2, 5, 12 and 15. Wound biopsies were harvested and the healing process was histopathologically evaluated on different days. qRT-PCR showed VEGF overexpression (sevenfold) in genetically-manipulated cells compared to fibroblast cells. Recombinant VEGF expression was also confirmed by western blotting. Manipulated fibroblast cells represented more angiogenesis than other groups on the second day after surgery, which was also confirmed by the antiCD31 antibody. The percentage of wound closure area on day 5 in genetically-manipulated Hu02 and Hu02 groups showed a significant reduction of wound area compared to other groups. These findings indicate that overexpression of VEGF₁₆₅ in fibroblast cells results in enhanced angiogenesis and formation of granulated tissue in the early stage of the healing process, which can show its therapeutic potential in patients with impaired wound healing and also provide functional support for gene therapy.

Facile microfluidic fabrication and characterization of ethyl cellulose/PVP films with neatly arranged fibers

Much attention and endeavor have been paid to developing biocompatible food packaging films. Here, ethyl cellulose (EC) and polyvinylpyrrolidone (PVP) were fabricated into films through a facile method, microfluidic spinning. Morphology observations showed that the fibers were neatly arranged with an average diameter of 1-4 μm. FTIR and X-ray diffraction analysis suggested the existence of good compatibility and interaction between EC and PVP. Thermogravimetric analysis demonstrated that PVP ameliorates the thermal properties; moreover, the tensile properties were improved, with tensile strength (TS) and Young's modulus up to 11.10 ± 1.04 MPa and 350.16 ± 45.46 MPa, respectively. The optimal formula was EC/PVP (2:3), of which the film displayed an enhanced TS of 4.61 ± 1.15 MPa and a modified water contact angle of 61.8 ± 4.4°, showing fine tensile and hydrophilic performance. This study provides a facile and green film fabrication method promising to be used for food wrapping.

Hybrid Films Prepared from a Combination of Electrospinning and Casting for Offering a Dual-Phase Drug Release

One of the most important trends in developments in electrospinning is to combine itself with traditional materials production and transformation methods to take advantage of the unique properties of nanofibers. In this research, the single-fluid blending electrospinning process was combined with the casting film method to fabricate a medicated double-layer hybrid to provide a dual-phase drug controlled release profile, with ibuprofen (IBU) as a common model of a poorly water-soluble drug and ethyl cellulose (EC) and polyvinylpyrrolidone (PVP) K60 as the polymeric excipients. Electrospun medicated IBU-PVP nanofibers (F7), casting IBU-EC films (F8) and the double-layer hybrid films (DHFs, F9) with one layer of electrospun nanofibers containing IBU and PVP and the other layer of casting films containing IBU, EC and PVP, were prepared successfully. The SEM assessments demonstrated that F7 were in linear morphologies without beads or spindles, F8 were solid films, and F9 were composed of one porous fibrous layer and one solid layer. XRD and FTIR results verified that both EC and PVP were compatible with IBU. In vitro dissolution tests indicated that F7 were able to provide a pulsatile IBU release, F8 offered a typical drug sustained release, whereas F9 were able to exhibit a dual-phase controlled release with 40.3 ± 5.1% in the first phase for a pulsatile manner and the residues were released in an extended manner in the second phase. The DHFs from a combination of electrospinning and the casting method pave a new way for developing novel functional materials.

Development of stimulus-sensitive electrospun membranes based on novel biodegradable segmented polyurethane as triggered delivery system for doxorubicin

In this work, redox-sensitive polyurethane urea (PUU) based electrospun membranes have been exploited to chemically tether a pH-sensitive doxorubicin derivative achieved by linking a lipoyl hydrazide to the drug via a hydrazone linkage. First, the lipoyl-hydrazone-doxorubicin derivative labelled as LA-Hy-Doxo has been synthesized and characterized. Then, the molecule has been tethered, via a thiol-disulfide exchange reaction, to the redox-sensitive PUU (PolyCEGS) electrospun membrane. The redox-sensitive PolyCEGS PUU has been produced by using PCL-PEG-PCL polyol and glutathione-tetramethyl ester (GSSG-OMe)₄ as a chain extender. The LA-Hy-Doxo tethered electrospun membrane has showed a dually controlled release triggered by acidic and reducing conditions, producing a significant cytotoxic effect in human breast cancer cell lines (MCF-7) which has validated the system for the post-surgical treatment of solid tumors to contrast recurrence.

Cellulose-Based Nanofibers Processing Techniques and Methods Based on Bottom-Up Approach-A Review

In the past decades, cellulose (one of the most important natural polymers), in the form of nanofibers, has received special attention. The nanofibrous morphology may provide exceptional properties to materials due to the high aspect ratio and dimensions in the nanometer range of the nanofibers. The first feature may lead to important consequences in mechanical behavior if there exists a particular orientation of fibers. On the other hand, nano-sizes provide a high surface-to-volume ratio, which can have important consequences on many properties, such as the wettability. There are two basic approaches for cellulose nanofibers preparation. The top-down approach implies the isolation/extraction of cellulose nanofibrils (CNFs) and nanocrystals (CNCs) from a variety of natural resources, whereby dimensions of isolates are limited by the source of cellulose and extraction procedures. The bottom-up approach can be considered in this context as the production of nanofibers using various spinning techniques, resulting in nonwoven mats or filaments. During the spinning, depending on the method and processing conditions, good control of the resulting nanofibers dimensions and, consequently, the properties of the produced materials, is possible. Pulp, cotton, and already isolated CNFs/CNCs may be used as precursors for spinning, alongside cellulose derivatives, namely esters and ethers. This review focuses on various spinning techniques to produce submicrometric fibers comprised of cellulose and cellulose derivatives. The spinning of cellulose requires the preparation of spinning solutions; therefore, an overview of various solvents is presented showing their influence on spinnability and resulting properties of nanofibers. In addition, it is shown how bottom-up spinning techniques can be used for recycling cellulose waste into new materials with added value. The application of produced cellulose fibers in various fields is also highlighted, ranging from drug delivery systems, high-strength nonwovens and filaments, filtration membranes, to biomedical scaffolds.

Preparation of nano sustained-release fertilizer using natural degradable polymer polylactic acid by coaxial electrospinning

Polylactic acid (PLA) is a novel biodegradable material that is widely used in fields like medicine, petrochemicals, disposable products, and has played significant role in the fast-growing agriculture sector in recent years. In this study, nanoscale sustained-release urea fiber materials were successfully fabricated by coaxial electrospinning by encapsulating urea inside polylactic acid fibers. The effects of different concentrations of PLA and urea on the preparation of fibrous membranes as well as the effects of different concentrations of PH and variations in temperature on the sustained release were investigated. The experimental results showed that the proposed method was feasible and the urea fiber membranes acidic and basic conditions as well as elevated temperatures. The sustained release time for the urea was as long as 84 d. Scanning electron microscopy and Fourier transform infrared spectrophotometry were employed to characterize the morphology of the electrospun nanofibers. Thermogravimetric analysis and differential scanning calorimetry showed that the release system was thermally stable up to a temperature of 126 °C, and urea concentration was determined by UV-Vis spectrophotometry. This method has broad application prospects in agricultural production and provides a more rational fertilizer choice for soil-free cultivation.

Electrospun ethyl cellulose/poly caprolactone/gelatin nanofibers: The investigation of mechanical, antioxidant, and antifungal properties for food packaging

The purpose of the present research was to fabricate ethylcellulose (ECL)/polycaprolactone (PCL)/gelatin (GEL) electrospun nanofibers containing Zataria multiflora essential oil (ZEO) and zinc oxide nanoparticle (ZnO) to provide an appropriate substrate for food packaging. The ECL/PCL/GEL was incorporated with ZEO and ZnO at the concentrations of 10, 20, 30 and 50 wt% and 3 wt%, respectively. The results of ECL/PCL/GEL/ZEO/ZnO nanofiber exhibited uniform morphology with a mean diameter ranging from 361.85 ± 18.7 to 467.33 ± 14.50 nm and enhanced thermal stability. The ECL/PCL/GEL/ZEO/ZnO nanofiber had the highest mechanical parameters, such as young's modulus (437.49 ± 18), tensile strength (7.88 ± 0.7), and elongation at break (5.02 ± 0.6) and water contact angle (61.13 ± 0.5), compared with the other nanofibers. The cell viability during 48 and 72 h was obtained to be about more than 80% for all the nanofibers. Additionally, the ECL/PCL/GEL incorporated with 50% ZEO and 3% ZnO displayed the highest antioxidant activity (34.61 ± 1.98%) and antifungal properties against Penicillium notatum and Aspergillus niger. In general, the ECL/PCL/GEL with the weight ratio of 20:70:10 nanofiber incorporated with 30% ZEO and 3% ZnO was obtained to have appropriate mechanical, antioxidant, and antimicrobial properties and thermal stability.

Biphasic Drug Release from Rolled-Up Gelatin Capsules with a Cylindrical Cavity

Biphasic drug delivery systems are used for quick release of a specific amount of drug for immediate amelioration of a patient’s state, followed by sustained release, to avoid repeated administration. This type of delivery is often necessary for pain management and the treatment of many pathologies, such as migraines, hypertension, and insomnia. In this work, we propose a novel architecture of a biphasic release media that does not need the rapidly disintegrating layer and that allows for easily setting the sustained release rate. A drug-containing capsule is made by rolling up a thermally crosslinked gelatin strip on which drug reservoirs are formed by casting. The quick-release reservoir (QRR) is placed at the strip’s extremity, from which the rolling starts, while the sustained-release reservoir (SRR) is formed in the middle part of the strip. The strip is rolled around a cylinder that is a few millimeters wide, which is removed after rolling. The roll is stabilized by transglutaminase-catalyzed crosslinking of the consecutive shells. A biphasic release is successfully demonstrated with the use of model fluorescent drugs for single-dye and double-dye systems in phosphate-buffered saline (PBS) solution with pH = 7.4. In vitro, the drug from the QRR, placed at the walls of the cavity of the roll, is released immediately upon the capsule’s contact with the PBS solution. The drug from the SRR, embedded between the roll’s layers, diffuses steadily, with the lag time defined by the radial position of the reservoir.

Stable Electrospinning of Core-Functionalized Coaxial Fibers Enabled by the Minimum-Energy Interface Given by Partial Core-Sheath Miscibility

Core-sheath electrospinning is a powerful tool for producing composite fibers with one or multiple encapsulated functional materials, but many material combinations are difficult or even impossible to spin together. We show that the key to success is to ensure a well-defined core-sheath interface while also maintaining a constant and minimal interfacial energy across this interface. Using a thermotropic liquid crystal as a model functional core and polyacrylic acid or styrene-butadiene-styrene block copolymer as a sheath polymer, we study the effects of using water, ethanol, or tetrahydrofuran as polymer solvent. We find that the ideal core and sheath materials are partially miscible, with their phase diagram exhibiting an inner miscibility gap. Complete immiscibility yields a relatively high interfacial tension that causes core breakup, even preventing the core from entering the fiber-producing jet, whereas the lack of a well-defined interface in the case of complete miscibility eliminates the core-sheath morphology, and it turns the core into a coagulation bath for the sheath solution, causing premature gelation in the Taylor cone. Moreover, to minimize Marangoni flows in the Taylor cone due to local interfacial tension variations, a small amount of the sheath solvent should be added to the core prior to spinning. Our findings resolve a long-standing confusion regarding guidelines for selecting core and sheath fluids in core-sheath electrospinning. These discoveries can be applied to many other material combinations than those studied here, enabling new functional composites of large interest and application potential.

Functional Hyaluronic Acid-Polylactic Acid/Silver Nanoparticles Core-Sheath Nanofiber Membranes for Prevention of Post-Operative Tendon Adhesion

In this study, we prepared core-sheath nanofiber membranes (CSNFMs) with silver nanoparticles (Ag NPs) embedding in the polylactic acid (PLA) nanofiber sheath and hyaluronic acid (HA) in the nanofiber core. The PLA/Ag NPs sheath provides mechanical support as well as anti-bacterial and anti-inflammatory properties. The controlled release of HA from the core could exert anti-adhesion effects to promote tendon sliding while reducing fibroblast attachment. From the microfibrous structural nature of CSNFMs, they function as barrier membranes to reduce fibroblast penetration without hampering nutrient transports to prevent post-operative peritendinous adhesion. As the anti-adhesion efficacy will depend on release rate of HA from the core as well as Ag NP from the sheath, we fabricated CSNFMs of comparable fiber diameter, but with thick (Tk) or thin (Tn) sheath. Similar CSNFMs with thick (Tk⁺) and thin (Tn⁺) sheath but with embedded Ag NPs in the sheath were also prepared. The physico-chemical properties of the barrier membranes were characterized in details, together with their biological response including cell penetration, cell attachment and proliferation, and cytotoxicity. Peritendinous anti-adhesion models in rabbits were used to test the efficacy of CSNFMs as anti-adhesion barriers, from gross observation, histology, and biomechanical tests. Overall, the CSNFM with thin-sheath and Ag NPs (Tn⁺) shows antibacterial activity with low cytotoxicity, prevents fibroblast penetration, and exerts the highest efficacy in reducing fibroblast attachment in vitro. From in vivo studies, the Tn⁺ membrane also shows significant improvement in preventing peritendinous adhesions as well as anti-inflammatory efficacy, compared with Tk and Tn CSNFMs and a commercial adhesion barrier film (SurgiWrap^®) made from PLA.

A Pharmacokinetic Evaluation of a Pectin-Based Oral Multiparticulate Matrix Carrier of Carbamazepine

Background

Carbamazepine is a drug used in the treatment of neurological disorders such as epilepsy. However, due to its erratic absorption, oral bioavailability is often poor. There is, therefore, the need to develop alternative formulations for carbamazepine with better pharmacokinetic characteristics.

Aim

The aim of this study was to formulate an oral modified-release multiparticulate matrix of carbamazepine from cocoa pod husk (CPH) pectin and evaluate the pharmacokinetic profile of this formulation using in vitro and in vivo models.

Methods

CPH pectin was extracted from cocoa pod husks with hot aqueous and citric acid solutions. Oral multiparticulate carbamazepine matrices were formulated from CPH pectin cross-linked with calcium. The formulation was evaluated for carbamazepine content and release profile in vitro. For in vivo pharmacokinetic profile estimation, rats were put into 4 groups of 5 animals each to receive carbamazepine multiparticulate matrix formulations A and B, carbamazepine powder, and Tegretol CR^®. Animals in each group received 200 mg/kg of each drug via the oral route. Maximum plasma concentration (C_max), area under the concentration-time curve (AUC), elimination rate constant (K_e), and terminal half-life (t_1/2) of the formulations were estimated by noncompartmental analysis.

Results

The pectin extraction from fresh cocoa pod husks using hot aqueous and citric acid solutions gave pectin yields of 9.63% and 11.54%, respectively. The drug content of carbamazepine in CPH pectin formulations A and B was 95% and 96%, respectively. There was controlled and sustained release of carbamazepine for both formulations A and B in vitro. AUC_0⟶36 (176.20 ± 7.97 µg.h/mL), C_max (8.45 ± 0.71 μg/mL), T_max (12 ± 1.28 h), and t_1/2 (13.75 ± 3.28 h) of formulation A showed a moderately enhanced and comparable pharmacokinetic profile to Tegretol CR^® (AUC_0⟶36: 155 ± 7.15 µg.h/mL, C_max: 8.24 ± 0.45 μg/mL, T_max: 8.0 ± 2.23 h, and t_1/2: 13.51 ± 2.87 h).

Conclusion

Findings from the study suggest that formulations of CPH pectin had the potential to control and maintain therapeutic concentrations of carbamazepine in circulation over a period of time in the rat model.

The efficiency of PCL/HAp electrospun nanofibers in bone regeneration: a review

Electrospinning is a method which produces various nanofiber scaffolds for different tissues was attractive for researchers. Nanofiber scaffolds could be made from several biomaterials and polymers. Quality and virtues of final scaffolds depend on used biomaterials (even about single substance, the origin is effective), additives (such as some molecules, ions, drugs, and inorganic materials), electrospinning parameter (voltage, injection speed, temperature, …), etc. In addition to its benefits, which makes it more attractive is the possibility of modifications. Common biomaterials in bone tissue engineering such as poly-caprolactone (PCL), hydroxyapatite (HAp), and their important features, electrospinning nanofibers were widely studied. Related investigations indicate the critical role of even small parameters (like the concentration of PCL or HAp) in final product properties. These changes also, cause deference in cell proliferation, adhesion, differentiation, and in vivo repair process. In this review was focussed on PCL/HAp based nanofibers and additives that researchers used for scaffold improvement. Then, reviewing properties of gained nanofibers, their effect on cell behaviour, and finally, their valency in bone tissue engineering studies (in vitro and in vivo).

Antibacterial Porous Coaxial Drug-Carrying Nanofibers for Sustained Drug-Releasing Applications

The phenomenon of drug burst release is the main problem in the field of drug delivery systems, as it means that a good therapeutic effect cannot be acheived. Nanofibers developed by electrospinning technology have large specific surface areas, high porosity, and easily controlled morphology. They are being considered as potential carriers for sustained drug release. In this paper, we obtained polycaprolactone (PCL)/polylactic acid (PLA) core-shell porous drug-carrying nanofibers by using coaxial electrospinning technology and the nonsolvent-induced phase separation method. Roxithromycin (ROX), a kind of antibacterial agent, was encapsulated in the core layer. The morphology, composition, and thermal properties of the resultant nanofibers were characterized by scanning electron microscopy (SEM), attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy, differential scanning calorimetry (DSC) and thermogravimetry analysis (TGA). Besides this, the in vitro drug release profile was investigated; it showed that the release rate of the prepared coaxial porous nanofibers with two different pore sizes was 30.10 ± 3.51% and 35.04 ± 1.98% in the first 30 min, and became 92.66 ± 3.13% and 88.94 ± 1.58% after 14 days. Compared with the coaxial nonporous nanofibers and nanofibers prepared by uniaxial electrospinning with or without pores, the prepared coaxial porous nanofibers revealed that the burst release was mitigated and the dissolution rate of the hydrophobic drugs was increased. The further antimicrobial activity demonstrated that the inhibition zone diameter of the coaxial nanofibers with two different pore sizes was 1.70 ± 0.10 cm and 1.73 ± 0.23 cm, exhibiting a good antibacterial effect against Staphylococcus aureus. Therefore, the prepared nanofibers with the coaxial porous structures could serve as promising drug delivery systems.

Statistically optimized pentazocine loaded microsphere for the sustained delivery application: Formulation and characterization

Pentazocine (PTZ) is a narcotic analgesic used to manage moderate to severe, acute and chronic pains. In this study, PTZ loaded Ethyl cellulose microsphere has been formulated for sustained release and improved bioavailability of PTZ. These microspheres were fabricated by oil in water emulsion solvent evaporation technique. A three factorial, three levels Box-Behnken design was applied to investigate the influence of different formulation components and process variables on the formulation response using the numeric approach through the design expert^® software. All the formulations were characterized for the morphology, different physicochemical properties and the results were supported with the ANOVA analysis, three dimensional contour graphs and regression equations. The maximum percentage yield was 98.67% with 98% entrapment of PTZ. The mean particle size of the formulations ranges from 50–148μm, which directly relates to the concentration of polymer and inversely proportional to the stirring speed. SEM revealed the spherical shape of PTZ microspheres with porous structures. These are physically, chemically and thermally stable as confirmed through Fourier transform infrared spectroscopy (FTIR), powder X-ray diffraction (PXRD) and thermal gravimetric (TG) analysis respectively. The microspheres provided a sustained release of the PTZ for more than 12 hours, following zero order with fickian and non fickian diffusion. The results indicate that prepared microspheres can be a potential drug delivery system (DDS) for the delivery of PTZ in the management of pains.

Electrospun Janus Beads-On-A-String Structures for Different Types of Controlled Release Profiles of Double Drugs

A side-by-side electrospinning process characterized by a home-made eccentric spinneret was established to produce the Janus beads-on-a-string products. In this study, ketoprofen (KET) and methylene blue (MB) were used as model drugs, which loaded in Janus beads-on-a-string products, in which polyvinylpyrrolidone K90 (PVP K90) and ethyl cellulose (EC) were exploited as the polymer matrices. From SEM images, distinct nanofibers and microparticles in the Janus beads-on-a-string structures could be observed clearly. X-ray diffraction demonstrated that all crystalline drugs loaded in Janus beads-on-a-string products were transferred into the amorphous state. ATR-FTIR revealed that the components of prepared Janus nanostructures were compatibility. In vitro dissolution tests showed that Janus beads-on-a-string products could provide typical double drugs controlled-release profiles, which provided a faster immediate release of MB and a slower sustained release of KET than the electrospun Janus nanofibers. Drug releases from the Janus beads-on-a-string products were controlled through a combination of erosion mechanism (linear MB-PVP sides) and a typical Fickian diffusion mechanism (bead KET-EC sides). This work developed a brand-new approach for the preparation of the Janus beads-on-a-string nanostructures using side-by-side electrospinning, and also provided a fresh idea for double drugs controlled release and the potential combined therapy.

Electrospun fixed dose combination fibers for the treatment of cardiovascular disease

Fixed dose combinations (FDCs) offer an accessible way to simplify complex therapeutic regimens by the simultaneous presentation of multiple drugs in a single entity to the patient. However, encapsulation of hydrophobic drugs into FDCs possess a number of technical challenges. Electrospinning comprises a convenient way to incorporate multiple hydrophobic drugs into a single formulation in a single step, via the use of an appropriate organic solvent system during fabrication. In this study, we report a series of novel fiber formulations comprising ethyl cellulose loaded with two hydrophobic drugs, spironolactone and nifedipine, either individually or in combination. The drugs are found to be present in the fibers in the form of amorphous solid dispersions, and these are stable at room temperature for 4 months. The products showed extended release profiles over more than 30 h. This formulation strategy offers potential to manage chronic cardiovascular conditions and overcome patient related non-adherence by providing a simplified treatment model.

Fabrication of Nanopores Polylactic Acid Microtubes by Core-Sheath Electrospinning for Capillary Vascularization

There has been substantial progress in tissue engineering of biological substitutes for medical applications. One of the major challenges in development of complex tissues is the difficulty of creating vascular networks for engineered constructs. The diameter of current artificial vascular channels is usually at millimeter or submillimeter level, while human capillaries are about 5 to 10 µm in diameter. In this paper, a novel core-sheath electrospinning process was adopted to fabricate nanoporous microtubes to mimic the structure of fenestrated capillary vessels. A mixture of polylactic acid (PLA) and polyethylene glycol (PEO) was used as the sheath solution and PEO was used as the core solution. The microtubes were observed under a scanning electron microscope and the images were analyzed by ImageJ. The diameter of the microtubes ranged from 1-8 microns. The diameter of the nanopores ranged from 100 to 800 nm. The statistical analysis showed that the microtube diameter was significantly influenced by the PEO ratio in the sheath solution, pump rate, and the viscosity gradient between the sheath and the core solution. The electrospun microtubes with nanoscale pores highly resemble human fenestrated capillaries. Therefore, the nanoporous microtubes have great potential to support vascularization in engineered tissues.

Effects of Polyvinylpyrrolidone and Ethyl Cellulose in Polyurethane Electrospun Nanofibers on Morphology and Drug Release Characteristics

Objectives

Polyurethanes (PUs) are a popular choice for composing nanofibers due to their spinnability, biocompatibility, high chemical stability, and good mechanical and elasticity properties. The desired release behaviors are also achieved by using combinations of PUs and various polymers. In this study, we investigated effects of polyvinylpyrrolidone (PVP) and ethyl cellulose (EC) on PU electrospun nanofibers in terms of morphological structures and drug release characteristics.

Materials and Methods

Nanofibers were prepared using blends of PU with either EC or PVP in different ratios by electrospinning. The effects of PVP or EC on the morphology and diameter of the prepared nanofibers were examined with scanning electron microscope (SEM). The compatibility of the components used in the formulations of nanofibers was determined by attenuated total reflection (ATR)-fourier-transform infrared (FTIR). Donepezil hydrochloride (DNP), a water soluble compound, was selected as a model drug to examine its release characteristics from both PU/PVP and PU/EC electrospun nanofibers. In vitro drug release studies from electrospun nanofibers were performed according to the method defined in the monograph as the "paddle over disk method" of United States Pharmacopeia 38.

Results

The SEM images showed that addition of EC or PVP to PU solutions did not affect the generation of nanofibers, and those formed had a smooth surface without beads in nanoscale. The ATR-FTIR spectra disclosed that EC and PVP were separately incorporated into the PU matrix. The in vitro release data indicated that the presence of EC or PVP in PU nanofibers dramatically changed the release behavior of DNP. PU/EC nanofibers (F4) provided sustained drug release with the Korsmeyer-Peppas drug release kinetic mechanism, in which the release rate was controlled by diffusion of the drug, while all of the PU/PVP nanofibers exhibited fast drug release.

Conclusion

Overall, these characteristics of PU/EC (10/8) electrospun nanofibers has suggested their potential use as a drug carrier from which water-soluble drug release may occur in a sustained fashion.

Pharmaceutical assessment of polyvinylpyrrolidone (PVP): As excipient from conventional to controlled delivery systems with a spotlight on COVID-19 inhibition

Polyvinylpyrrolidone (PVP) is a water-soluble polymer obtained by polymerization of monomer N-vinylpyrrolidone. PVP is an inert, non-toxic, temperature-resistant, pH-stable, biocompatible, biodegradable polymer that helps to encapsulate and cater both hydrophilic and lipophilic drugs. These advantages enable PVP a versatile excipient in the formulation development of broad conventional to novel controlled delivery systems. PVP has tunable properties and can be used as a brace component for gene delivery, orthopedic implants, and tissue engineering applications. Based on different molecular weights and modified forms, PVP can lead to exceptional beneficial features with varying chemical properties. Graft copolymerization and other techniques assist PVP to conjugate with poorly soluble drugs that can inflate bioavailability and even introduces the desired swelling tract for their control or sustained release. The present review provides chemistry, mechanical, physicochemical properties, evaluation parameters, dewy preparation methods of PVP derivatives intended for designing conventional to controlled systems for drug, gene, and cosmetic delivery. The past and growing interest in PVP establishes it as a promising polymer to enhance the trait and performance of current generation pharmaceutical dosage forms. Furthermore, the scrutiny explores existing patents, marketed products, new and futuristic approaches of PVP that have been identified and scope for future development, characterization, and its use. The exploration spotlights the importance and role of PVP in the design of Povidone-iodine (PVP-I) and clinical trials to assess therapeutic efficacy against the COVID-19 in the current pandemic scenario.

Synthesis, characterization and oxygen sensitivity of cyclophosphazene equipped-iridium (III) complexes

In this work, synthesis, characterization and oxygen sensing abilities of the cyclophosphazene-free and phenyl and naphtoxy-substituted cyclophosphazene bearing iridium (III) complexes (Ir-I, Ir-II and Ir-III) were presented. The complexes were characterized by NMR, absorption and emission spectroscopies, luminescence lifetime and quantum yield measurements. The molecules were successfully embedded in the ethyl cellulose matrix to fabricate the oxygen sensing electrospun mats via electrospinning technique. Oxygen induced luminescence of the iridium complexes around 600 nm has been followed as the analytical signal during oxygen sensitivity studies. They exhibited blue shifted, quenched emission towards triplet oxygen. The napthoxy substituted derivative exhibited 2.70 fold enhanced I₀/I₁₀₀ ratio compared to the free form in terms of the relative signal change. Room-temperature luminescence abilities, high photostabilities, large Stoke's shift values extending to 200 nm and high spectral response, especially between 0 and 10% pO₂ make them promising candidates as oxygen probes. The test materials can be stored at the ambient air of the laboratory for at least 24 months.

Spray-Dried Rosuvastatin Nanoparticles for Promoting Hair Growth

In this research, we examined the effect of rosuvastatin calcium-loaded nanoparticles on the hair growth-promoting activity on Albino rats. Nanoparticles were prepared using 2:1 weight ratio of drug to methyl-β-cyclodextrin with 10, 20, and 30% stabilizers (phospholipid, polyvinyl pyrrolidone K30, and Compritol 888 ATO) using nanospray dryer. Subsequently, the prepared nanoparticles were evaluated for their process yield, particle size, polydispersity index, zeta potential, and in vitro drug release as well as in vivo studies. The dried nanoparticles showed process yield values up to 84% with particle size values ranging from 218 to 6258 nm, polydispersity index values ranging from 0.32 to 0.99, and zeta potential values ranging from - 6.1 to - 11.9 mV. Combination of methyl-β-cyclodextrin with 10% polyvinyl pyrrolidone K30 accomplished nanoparticles with the lowest particle size (218 nm) and polydispersity index (0.32) values. These nanoparticles had suitable process yield value (70.5%) and were able to retard drug release. The hair growth-promoting activity for the selected nanoparticles revealed the highest hair length values in Albino rats after 14 days of the hair growth study compared with non-medicated nanoparticles, nanoparticles' physical mixture, rosuvastatin solution, and marketed minoxidil preparation groups as well as the control group. The immunohistochemistry images for both selected nanoparticles and marketed minoxidil groups showed a significant increase in the diameter of hair follicle and percent area fraction of cytokeratin 19 in the outer root sheath of hair follicle compared with other tested groups. Rosuvastatin nanoparticles prepared by nanospray drying technique could be a good competitor to minoxidil for hair growth-promoting activity. Graphical abstract.

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.

Polycaprolactone/polyvinylpyrrolidone coaxial electrospun fibers containing veratric acid-loaded chitosan nanoparticles for bone regeneration

Veratric acid (3,4-dimethoxy benzoic acid) (VA) is a hydrophobic phenolic phytocompound possessing therapeutic potential, but it has not been reported as actuating bone regeneration to date. Furthermore, delivery of hydrophobic compounds is often impeded in the body, thus depreciating their bioavailability. In this study, VA was found to have osteogenic potential and its sustained delivery was facilitated through a nanoparticle-embedded coaxial electrospinning technique. Polycaprolactone/polyvinylpyrrolidone (PCL/PVP) coaxial fibers were electrospun, encasing VA-loaded chitosan nanoparticles (CHS-NP). The fibers showed commendable physiochemical and material properties and were biocompatible with mouse mesenchymal stem cells (mMSCs). When mMSCs were grown on coaxial fibers, VA promoted these cells towards osteoblast differentiation as was reflected by calcium deposits. The mRNA expression of Runx2, an important bone transcriptional regulator, and other differentiation markers such as alkaline phosphatase, collagen type I, and osteocalcin were found to be upregulated in mMSCs grown on the PCL/PVP/CHS-NP-VA fibers. Overall, the study portrays the delivery of the phytocompound, VA, in a sustained manner to promote bone regeneration.

Large-Scale and Rapid Preparation of Nanofibrous Meshes and Their Application for Drug-Loaded Multilayer Mucoadhesive Patch Fabrication for Mouth Ulcer Treatment

Electrospinning provides a simple and convenient method to fabricate nanofibrous meshes. However, the nanofiber productivity is often limited to the laboratory scale, which cannot satisfy the requirements of practical application. In this study, we developed a novel needleless electrospinning spinneret based on a double-ring slit to fabricate drug-loaded nanofibrous meshes. In contrast to the conventional single-needle electrospinning spinneret, our needless spinneret can significantly improve nanofiber productivity due to the simultaneous formation of multiple jets during electrospinning. Curcumin-loaded poly(l-lactic acid) (PLLA) nanofiber meshes with various concentrations and on the large scale were manufactured by employing our developed needleless spinneret-based electrospinning device. We systematically investigated the drug release behaviors, antioxidant properties, anti-inflammatory attributes, and cytotoxicity of the curcumin-loaded PLLA nanofibrous meshes. Furthermore, a bilayer nanofibrous composite mesh was successfully generated by electrospinning curcumin-loaded PLLA solution and diclofenac sodium loaded poly(ethylene oxide) solution in a predetermined time sequence, which revealed potent antibacterial properties. Subsequently, novel mucoadhesive patches were assembled by combining the bilayer composite nanofibrous meshes with (hydroxypropyl)methyl cellulose based mucoadhesive film. The multilayered mucoadhesive patch has excellent adhesion properties on the porcine buccal mucosa. Overall, our double-ring slit spinneret can provide a novel method to rapidly produce large-scale drug-loaded nanofibrous meshes to fabricate mucoadhesive patches. The multiple-layered mucoadhesive patches enable the incorporation of multiple drugs with different targets of action, such as analgesic, anti-inflammatory, and antimicrobial compounds, for mouth ulcer or other oral disease treatments.

Emerging frontiers in drug release control by core-shell nanofibers: a review

In recent years, core-shell (CS) nanofiber has widely been used as a carrier for controlled drug release. This outstanding attention toward CS nanofiber is mainly due to its tremendous significance in controllable drug release in specific locations. The major advantage of CS nanofibers is forming a highly porous mesh, boosting its performance for many applications, due to its large surface-to-volume ratio. This inherently high ratio has prompted electrospun fibers to be considered one of the best drug-delivery-systems available, with the capacity to enhance properties such as cell attachment, drug loading, and mass transfer. Using electrospun fibers as CS nanofibers to incorporate different cargos such as antibiotics, anticancer agents, proteins, DNA, RNA, living cells, and diverse growth factors would considerably satisfy the need for a universal carrier in the field of nanotechnology. In addition to their high surface area, other benefit included in these nanofibers is the ability to trap drugs, easily controlled morphology, and their biomimetic characteristics. In this review, by taking the best advantages of the preparation and uses of CS nanofibers, a novel work in the domain of the controlled drug delivery by nanofiber-based scaffolds is presented.

Drug Delivery Applications of Core-Sheath Nanofibers Prepared by Coaxial Electrospinning: A Review

Electrospinning has emerged as one of the potential techniques for producing nanofibers. The use of electrospun nanofibers in drug delivery has increased rapidly over recent years due to their valuable properties, which include a large surface area, high porosity, small pore size, superior mechanical properties, and ease of surface modification. A drug loaded nanofiber membrane can be prepared via electrospinning using a model drug and polymer solution; however, the release of the drug from the nanofiber membrane in a safe and controlled way is challenging as a result of the initial burst release. Employing a core-sheath design provides a promising solution for controlling the initial burst release. Numerous studies have reported on the preparation of core-sheath nanofibers by coaxial electrospinning for drug delivery applications. This paper summarizes the physical phenomena, the effects of various parameters in coaxial electrospinning, and the usefulness of core-sheath nanofibers in drug delivery. Furthermore, this report also highlights the future challenges involved in utilizing core-sheath nanofibers for drug delivery applications.

Tunable drug release from blend poly(vinyl pyrrolidone)-ethyl cellulose nanofibers

The management of pain and inflammation arising from wounds is essential in obtaining effective healing rates. The application of a wound dressing loaded with an anti-inflammatory drug would enable both issues to be ameliorated, and the aim of this work was to fabricate such a dressing by electrospinning. Fibers comprising ethyl cellulose (EC) and poly(vinyl pyrrolidone) (PVP) loaded with naproxen (Nap) were developed to be used in the early stages of wound care. A family of PVP/EC/Nap systems was prepared by varying the PVP: EC ratio. In all cases, the products of electrospinning comprise non-woven mats of fibers which generally have smooth and cylindrical morphologies. The formulations exist as amorphous solid dispersions, and there appear to be intermolecular interactions between the three components. Adjusting the polymer ratios results in tunable drug release, and formulations have been produced which give zero-order drug release over 20 and 80 h. The fiber mats generated in this work thus have great potential to be used as dressings for the treatment of wound pain and inflammation.

Fabrication of Electrospun Polymer Nanofibers with Diverse Morphologies

Fiber structures with nanoscale diameters offer many fascinating features, such as excellent mechanical properties and high specific surface areas, making them attractive for many applications. Among a variety of technologies for preparing nanofibers, electrospinning is rapidly evolving into a simple process, which is capable of forming diverse morphologies due to its flexibility, functionality, and simplicity. In such review, more emphasis is put on the construction of polymer nanofiber structures and their potential applications. Other issues of electrospinning device, mechanism, and prospects, are also discussed. Specifically, by carefully regulating the operating condition, modifying needle device, optimizing properties of the polymer solutions, some unique structures of core⁻shell, side-by-side, multilayer, hollow interior, and high porosity can be obtained. Taken together, these well-organized polymer nanofibers can be of great interest in biomedicine, nutrition, bioengineering, pharmaceutics, and healthcare applications.