Dual drug-loaded coaxial nanofibers for the treatment of corneal abrasion

Coaxial Electrospun Polycaprolactone/Gelatin Nanofiber Membrane Loaded with Salidroside and Cryptotanshinone Synergistically Promotes Vascularization and Osteogenesis

Background

Salidroside (SAL) is the most effective component of Rhodiola rosea, a traditional Chinese medicine. Cryptotanshinone (CT) is the main fat-soluble extract of Salvia miltiorrhiza, exhibiting considerable potential for application in osteogenesis. Herein, a polycaprolactone/gelatin nanofiber membrane loaded with CT and SAL (PSGC membrane) was successfully fabricated via coaxial electrospinning and characterized.

Methods and Results

This membrane capable of sustained and controlled drug release was employed in this study. Co-culturing the membrane with bone marrow mesenchymal stem cells and human umbilical vein endothelial cells revealed excellent biocompatibility and demonstrated osteogenic and angiogenic capabilities. Furthermore, drug release from the PSGC membrane activated the Wnt/β-catenin signaling pathway and promoted osteogenic differentiation and vascularization. Evaluation of the membrane's vascularization and osteogenic capacities involved transplantation onto a rat's subcutaneous area and assessing rat cranium defects for bone regeneration, respectively. Microcomputed tomography, histological tests, immunohistochemistry, and immunofluorescence staining confirmed the membrane's outstanding angiogenic capacity two weeks post-operation, with a higher incidence of osteogenesis observed in rat cranial defects eight weeks post-surgery.

Conclusion

Overall, the SAL- and CT-loaded coaxial electrospun nanofiber membrane synergistically enhances bone repair and regeneration.

Dual Drug-Loaded Coaxial Nanofiber Dressings for the Treatment of Diabetic Foot Ulcer

Introduction

Diabetes mellitus is frequently associated with foot ulcers, which pose significant health risks and complications. Impaired wound healing in diabetic patients is attributed to multiple factors, including hyperglycemia, neuropathy, chronic inflammation, oxidative damage, and decreased vascularization.

Rationale

To address these challenges, this project aims to develop bioactive, fast-dissolving nanofiber dressings composed of polyvinylpyrrolidone loaded with a combination of an antibiotic (moxifloxacin or fusidic acid) and anti-inflammatory drug (pirfenidone) using electrospinning technique to prevent the bacterial growth, reduce inflammation, and expedite wound healing in diabetic wounds.

Results

The fabricated drug-loaded fibers exhibited diameters of 443 ± 67 nm for moxifloxacin/pirfenidone nanofibers and 488 ± 92 nm for fusidic acid/pirfenidone nanofibers. The encapsulation efficiency, drug loading and drug release studies for the moxifloxacin/pirfenidone nanofibers were found to be 70 ± 3% and 20 ± 1 µg/mg, respectively, for moxifloxacin, and 96 ± 6% and 28 ± 2 µg/mg, respectively, for pirfenidone, with a complete release of both drugs within 24 hours, whereas the fusidic acid/pirfenidone nanofibers were found to be 95 ± 6% and 28 ± 2 µg/mg, respectively, for fusidic acid and 102 ± 5% and 30 ± 2 µg/mg, respectively, for pirfenidone, with a release rate of 66% for fusidic acid and 80%, for pirfenidone after 24 hours. The efficacy of the prepared nanofiber formulations in accelerating wound healing was evaluated using an induced diabetic rat model. All tested formulations showed an earlier complete closure of the wound compared to the controls, which was also supported by the histopathological assessment. Notably, the combination of fusidic acid and pirfenidone nanofibers demonstrated wound healing acceleration on day 8, earlier than all tested groups.

Conclusion

These findings highlight the potential of the drug-loaded nanofibrous system as a promising medicated wound dressing for diabetic foot applications.

A Periosteum-Bioinspired Electrospun Janus Membrane with Antibacterial and Osteogenic Dual Function

For a guided bone regeneration membrane, it is critical to possess osteogenic capability while inhibiting infection caused by bacteria. Inspired by the bilayer structure of the native periosteum, an electrospun Janus membrane with osteogenic and antibacterial dual-function is fabricated for guided bone regeneration. Hydrophilic moxifloxacin (MXF) and hydrophobic icariin (ICA) are loaded in the nanofibers made of a mixture of polycaprolactone and gelatin at the top and bottom layers, respectively, leading to the opposing hydrophilic/hydrophobic properties of the bilayer Janus membranes. The as-obtained Janus membrane exhibits excellent physical properties (tensile strength > 6.0 MPa) and robust biocompatibility, indicating the immense potential as a suitable replacement for the native periosteum. The membrane has a superior surface morphology and outstanding degradation performance in vitro. Besides, the rapid release of MXF and the slow release of ICA can meet the different needs of drug release rates. Only ≈30% ICA is released from the as-obtained Janus membrane after 21 d while almost 80% MXF is released. Mimicking the bilayer structure of the native periosteum, the electrospun Janus membrane containing ICA and MXF exhibits excellent comprehensive properties, which provides a promising strategy for preparing multifunctional scaffolds for tissue engineering.

Fabrication and evaluation of ribavirin-loaded electrospun nanofibers as an antimicrobial wound dressing

Background

Skin is regarded as an essential first line of defense against harmful pathogens and it hosts an ecosystem of microorganisms that create a widely diverse skin microbiome. In chronic wounds, alterations in the host-microbe interactions occur forming polymicrobial biofilms that hinder the process of wound healing. Ribavirin, an antiviral drug, possesses antimicrobial activity, especially against Pseudomonas aeruginosa and Candida albicans, which are known as the main opportunistic pathogens in chronic wounds.

Rationale

In this study, electrospun nanofiber systems loaded with ribavirin were developed as a potential wound dressing for topical application in chronic wounds. Ribavirin was chosen in this study owing to the emerging cases of antimicrobial (antibiotics and antifungal) resistance and the low attempts to discover new antimicrobial agents, which encouraged the repurposing use of current medication as an alternative solution in case of resistance to the available agents. Additionally, the unique mechanism of action of ribavirin, i.e., perturbing the bacterial virulence system without killing or stopping their growth and rendering the pathogens disarmed, might be a promising choice to prevent drug resistance. Cyclodextrin (CD) was utilized to formulate ribavirin as an electrospun nanofibers delivery system to enhance the absorption and accelerate the release of ribavirin for topical use.

Results

The results demonstrated a successful ribavirin nanofibers fabrication that lacked beads and pores on the nanofibrous surfaces. Ribavirin underwent a physical transformation from crystalline to amorphous form, as confirmed by X-ray diffraction analysis. This change occurred due to the molecular dispersion after the electrospinning process. Additionally, the CD enhanced the encapsulation efficiency of ribavirin in the nanofibers as observed from the drug-loading results. Polyvinylpyrrolidone (PVP) and CD increased ribavirin released into the solution and the disintegration of fibrous mats which shrank and eventually dissolved into a gel-like substance as the ribavirin-loaded fibers began to break down from their border toward the midpoint. Cytotoxicity of ribavirin and CD was evaluated against human dermal fibroblasts (HFF-1) and the results showed a relatively safe profile of ribavirin upon 24-hour cell exposure, while CD was safe within 24- and 48-hour.

Conclusion

This study provides valuable insights into the potential application of our nanofibrous system for treating chronic wounds; however, further antimicrobial and in-vivo studies are required to confirm its safety and effectiveness.

Pirfenidone: A Promising Drug in Ocular Therapeutics

Pirfenidone, initially indicated for lung fibrosis, has gone beyond its original purpose, and shown promise in eye care. This detailed review tracks its evolution from lung treatment to aiding eye healing as evidenced by published literature. Pirfenidone's multifaceted attributes extend to mitigating corneal fibrosis, inflammation, and trauma. Through rigorous investigations, its efficacy emerges in diabetic retinopathy, macular degeneration, and postoperative glaucoma interventions. As an unheralded protagonist, pirfenidone reshapes ocular care paradigms, inviting renewed research opportunities.

Application of Electrospun Drug-Loaded Nanofibers in Cancer Therapy

In the 21st century, chemotherapy stands as a primary treatment method for prevalent diseases, yet drug resistance remains a pressing challenge. Utilizing electrospinning to support chemotherapy drugs offers sustained and controlled release methods in contrast to oral and implantable drug delivery modes, which enable localized treatment of distinct tumor types. Moreover, the core-sheath structure in electrospinning bears advantages in dual-drug loading: the core and sheath layers can carry different drugs, facilitating collaborative treatment to counter chemotherapy drug resistance. This approach minimizes patient discomfort associated with multiple-drug administration. Electrospun fibers not only transport drugs but can also integrate metal particles and targeted compounds, enabling combinations of chemotherapy with magnetic and heat therapies for comprehensive cancer treatment. This review delves into electrospinning preparation techniques and drug delivery methods tailored to various cancers, foreseeing their promising roles in cancer treatment.

Advanced 3D Electrospinning "Xspin" System: Fabrication of Bifiber Floating Oral Pharmaceutical Scaffolds for Controlled Drug Delivery

Electrospinning has become a widely used and efficient method for manufacturing nanofibers from diverse polymers. This study introduces an advanced electrospinning technique, Xspin - a multi-functional 3D printing platform coupled with electrospinning system, integrating a customised 3D printhead, MaGIC - Multi-channeled and Guided Inner Controlling printheads. The Xspin system represents a cutting-edge fusion of electrospinning and 3D printing technologies within the realm of pharmaceutical sciences and biomaterials. This innovative platform excels in the production of novel fiber with various materials and allows for the creation of highly customized fiber structures, a capability hitherto unattainable through conventional electrospinning methodologies. By integrating the benefits of electrospinning with the precision of 3D printing, the Xspin system offers enhanced control over the scaffold morphology and drug release kinetics. Herein, we fabricated a model floating pharmaceutical dosage for the dual delivery of curcumin and ritonavir and thoroughly characterized the product. Fourier transform infrared (FTIR) spectroscopy demonstrated that curcumin chemically reacted with the polymer during the Xspin process. Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) confirmed the solid-state properties of the active pharmaceutical ingredient after Xspin processing. Scanning electron microscopy (SEM) revealed the surface morphology of the Xspin-produced fibers, confirming the presence of the bifiber structure. To optimize the quality and diameter control of the electrospun fibers, a design of experiment (DoE) approach based on quality by design (QbD) principles was utilized. The bifibers expanded to approximately 10-11 times their original size after freeze-drying and effectively entrapped 87% curcumin and 84% ritonavir. In vitro release studies demonstrated that the Xspin system released 35% more ritonavir than traditional pharmaceutical pills in 2 h, with curcumin showing complete release in pH 1.2 in 5 min, simulating stomach media. Furthermore, the absorption rate of curcumin was controlled by the characteristics of the linked polymer, which enables both drugs to be absorbed at the desired time. Additionally, multivariate statistical analyses (ANOVA, pareto chart, etc.) were conducted to gain better insights and understanding of the results such as discern statistical differences among the studied groups. Overall, the Xspin system shows significant potential for manufacturing nanofiber pharmaceutical dosages with precise drug release capabilities, offering new opportunities for controlled drug delivery applications.

Development of progesterone electrospun nanofibers to coat Arabin pessaries as a dual preventive and therapeutic approach for preterm labor

Preterm labor is a growing health problem that causes newborn death, and safe and effective therapy is significantly needed. Arabin pessaries and progesterone are preventive and therapeutic approaches that can be applied to managing the short cervix; hence, reducing the risk of preterm labor. The main goal of current work is to fabricate a novel nanofiber formulation based on polycaprolactone (PCL) and loaded with progesterone to coat for Arabin pessaries to be used as dual preventive and therapeutic approaches for local vaginal delivery. Several important criteria were considered in this study to assess the prepared nanofibers (i.e.; nanofiber diameter, progesterone loading efficiency, progesterone release profiles and in vitro cytotoxicity assessment). The results showed a dimeter of 397 ± 88 nm, drug loading of 142 ± 3 µg/mg and encapsulation efficiency of 99 ± 2 % for the progesterone-loaded nanofibers. Approximately, 17 % of progesterone was released from the nanofibers after 90 days. The in vitro assessment showed that the application of progesterone is safe upon 24 and 48-hours incubation on HFF-1 cell line at concentrations ≤ 32 µg/mL and within 72-hours at a dose of ≤ 8 µg/mL. To conclude, the data recommended that progesterone-loaded nanofibers can coat the Arabin pessaries with the potential of being a safe and effective dual preventive and therapeutic tool for preterm labor.

Eflornithine Hydrochloride-Loaded Electrospun Nanofibers as a Potential Face Mask for Hirsutism Application

Hirsutism is a distressing condition that can affect women's self-esteem due to the excessive amount of hair growth in different body parts, including the face. A temporary managing option is to develop a self-care routine to remove unwanted hair through shaving or waxing. Laser or electrolysis are alternative methods, but in some cases, the use of medications, such as the topical cream Vaniqa®, can help in reducing the growth of unwanted hair. Electrospun fibers have been used in several drug delivery applications, including skin care products, owing to their biocompatibility, biodegradability, high surface area-to-volume ratio, and dry nature that can release the encapsulated drugs with maximum skin penetration. Therefore, polyvinyl pyrrolidone (PVP) fibers were fabricated in combination with hyaluronic acid to deliver the active compound of Vaniqa®, i.e., Eflornithine hydrochloride (EFH), as a face mask to inhibit excess facial hair growth. The prepared drug-loaded fibers showed a diameter of 490 ± 140 nm, with an encapsulation efficiency of 88 ± 7% and a drug loading capacity of 92 ± 7 μg/mg. The in vitro drug release of EFH-loaded fibers exhibited an initial burst release of 80% in the first 5 min, followed by a complete release after 360 min, owing to the rapid disintegration of the fibrous mat (2 s). The in vitro cytotoxicity indicated a high safety profile of EFH at all tested concentrations (500-15.625 μg/mL) after 24-h exposure to human dermal fibroblast (HFF-1) cells. Therefore, this drug-loaded nanofibrous system can be considered a potentially medicated face mask for the management of hirsutism, along with the moisturizing effect that it possesses. Topical applications of the developed system showed reduced hair growth in mice to a certain extent.

Solid implantable devices for sustained drug delivery

Implantable drug delivery systems (IDDS) are an attractive alternative to conventional drug administration routes. Oral and injectable drug administration are the most common routes for drug delivery providing peaks of drug concentrations in blood after administration followed by concentration decay after a few hours. Therefore, constant drug administration is required to keep drug levels within the therapeutic window of the drug. Moreover, oral drug delivery presents alternative challenges due to drug degradation within the gastrointestinal tract or first pass metabolism. IDDS can be used to provide sustained drug delivery for prolonged periods of time. The use of this type of systems is especially interesting for the treatment of chronic conditions where patient adherence to conventional treatments can be challenging. These systems are normally used for systemic drug delivery. However, IDDS can be used for localised administration to maximise the amount of drug delivered within the active site while reducing systemic exposure. This review will cover current applications of IDDS focusing on the materials used to prepare this type of systems and the main therapeutic areas of application.

Electrospun Nanofiber Composites for Drug Delivery: A Review on Current Progresses

A medication’s approximate release profile should be sustained in order to generate the desired therapeutic effect. The drug’s release site, duration, and rate must all be adjusted to the drug’s therapeutic aim. However, when designing drug delivery systems, this may be a considerable hurdle. Electrospinning is a promising method of creating a nanofibrous membrane since it enables drugs to be placed in the nanofiber composite and released over time. Nanofiber composites designed through electrospinning for drug release purposes are commonly constructed of simple structures. This nanofiber composite produces matrices with nanoscale fiber structure, large surface area to volume ratio, and a high porosity with small pore size. The nanofiber composite’s large surface area to volume ratio can aid with cell binding and multiplication, drug loading, and mass transfer processes. The nanofiber composite acts as a container for drugs that can be customized to a wide range of drug release kinetics. Drugs may be electrospun after being dissolved or dispersed in the polymer solution, or they can be physically or chemically bound to the nanofiber surface. The composition and internal structure of the nanofibers are crucial for medicine release patterns.

Advancement of Nanofibrous Mats and Common Useful Drug Delivery Applications

Electrospinning enables simple and cost-effective production of polymer nanofibers from different polymer materials. Drug delivery systems are capable of achieving maximum drug treatment benefits by significantly reducing adverse complications. Electrospun nanofibers have recently attracted considerable attention owing to their distinctive properties, including flexibility and biocompatibility. The implementation of functional constituents within nanostructure fibers blends is an effective technique for the administration of a variety of drugs in animal research, broadening the nanofiber capability and reliability. The nanofibrous mesh and its various application purposes are discussed in terms of a summary of recent research, emphasizing the ease of streaming and a large number of combinations of this approach, which could lead to a breakthrough in targeted therapy.

Fast-Dissolving Nifedipine and Atorvastatin Calcium Electrospun Nanofibers as a Potential Buccal Delivery System

Geriatric patients are more likely to suffer from multiple chronic diseases that require using several drugs, which are commonly ingested. However, to enhance geriatric patients’ convenience, the electrospun nanofiber system was previously proven to be a successful alternative for the existing oral dosage forms, i.e., tablets and capsules. These nanofibers prepared either as single- or multi-layered fibers could hold at least one active compound in each layer. They might also be fabricated as ultra-disintegrated fibrous films for oral cavity administration, i.e., buccal or sublingual, to improve the bioavailability and intake of the administered drugs. Therefore, in this work, a combination of nifedipine and atorvastatin calcium, which are frequently prescribed for hypertension and hyperlipidemia patients, respectively, was prepared in a coaxial electrospinning system for buccal administration. Scanning electron microscopy image showed the successful preparation of smooth, non-beaded, and non-porous surfaces of the drug-loaded nanofibers with an average fiber diameter of 968 ± 198 nm. In contrast, transmission electron microscopy distinguished the inner and outer layers of those nanofibers. The disintegration of the drug-loaded nanofibers was ≤12 s, allowing the rapid release of nifedipine and atorvastatin calcium to 61% and 47%, respectively, after 10 min, while a complete drug release was achieved after 120 min. In vitro, a drug permeation study using Franz diffusion showed that the permeation of both drugs from the core–shell nanofibers was enhanced significantly (p < 0.05) compared to the drugs in a solution form. In conclusion, the development of drug-loaded nanofibers containing nifedipine and atorvastatin calcium can be a potential buccal delivery system.

Utilising Co-Axial Electrospinning as a Taste-Masking Technology for Paediatric Drug Delivery

The present study describes the use of two taste-masking polymers to fabricate a formulation of chlorpheniramine maleate for paediatric administration. Co-axial electrospinning was utilized to create layered nanofibres; the two polymers, Eudragit® E PO and Kollicoat® Smartseal, were alternated between the core and the shell of the system in order to identify the optimum taste-masked formulation. The drug was loaded in the core on all occasions. It was found that the formulation with Kollicoat® Smartseal in the core with the drug, and Eudragit® E PO in the shell showed the most effective taste-masking compared to the other formulations. These fibres were in the nano-range and had smooth morphology as verified by scanning electron microscopy. Solid-state characterization and thermal analysis confirmed that amorphous solid dispersions were formed upon electrospinning. The Insent E-tongue was used to assess the taste-masking efficiency of the samples, and it was found that this formulation was undetectable by the bitter sensor, indicating successful taste-masking compared to the raw version of the drug. The E-tongue also confirmed the drug's bitterness threshold as compared to quinine HCl dihydrate, a parameter that is useful for formulation design and taste-masking planning.

A Systematic Review of Drug-Loaded Electrospun Nanofiber-Based Ophthalmic Inserts

Currently, ocular inserts and nanoparticles have received much attention due to the limited bioavailability of conventional eye preparations and the toxicity problems of systemic drug administration. The current systematic review aims to present recent studies on the use of electrospun nanofiber-based ocular inserts to improve the bioavailability of drugs used for different ophthalmic diseases. A systematic search was performed in PubMed, Ovid Medline, Web of Science, ScienceDirect, Scopus, Reaxys, Google Scholar, and Google Patents/Espacenet taking "drug-loaded", "nanofibers", and "ophthalmic inserts" and their equivalent terms as keywords. The search was limited to original and peer-reviewed studies published in 2011-2021 in English language. Only 13 out of 795 articles and 15 out of 197 patents were included. All results revealed the success of nanofiber-based ocular inserts in targeting and improved bioavailability. Ocular inserts based on nanofibers can be used as safe, efficient carriers for the treatment of anterior and posterior eye diseases.

Drug delivery to the anterior segment of the eye: A review of current and future treatment strategies

Research in the development of ophthalmic drug formulations and innovative technologies over the past few decades has been directed at improving the penetration of medications delivered to the eye. Currently, approximately 90% of all ophthalmic drug formulations (e.g. liposomes, micelles) are applied as eye drops. The major challenge of topical eye drops is low bioavailability, need for frequent instillation due to the short half-life, poor drug solubility, and potential side effects. Recent research has been focused on improving topical drug delivery devices by increasing ocular residence time, overcoming physiological and anatomical barriers, and developing medical devices and drug formulations to increase the duration of action of the active drugs. Researchers have developed innovative technologies and formulations ranging from sub-micron to macroscopic size such as prodrugs, enhancers, mucus-penetrating particles (MPPs), therapeutic contact lenses, and collagen corneal shields. Another approach towards the development of effective topical drug delivery is embedding therapeutic formulations in microdevices designed for sustained release of the active drugs. The goal is to optimize the delivery of ophthalmic medications by achieving high drug concentration with prolonged duration of action that is convenient for patients to administer.

Fabrication and Characterization of Fast-Dissolving Films Containing Escitalopram/Quetiapine for the Treatment of Major Depressive Disorder

Major depressive disorder (MMD) is a leading cause of disability worldwide. Approximately one-third of patients with MDD fail to achieve response or remission leading to treatment-resistant depression (TRD). One of the psychopharmacological strategies to overcome TRD is using a combination of an antipsychotic as an augmenting agent with selective serotonin reuptake inhibitors (SSRIs). Among which, an atypical antipsychotic, quetiapine (QUE), and an SSRI, escitalopram (ESC), were formulated as a fixed-dose combination as a fast-dissolving film by coaxial electrospinning. The resultant fiber’s morphology was studied. SEM images showed that the drug-loaded fibers were smooth, un-beaded, and non-porous with a fiber diameter of 0.9 ± 0.1 µm, while the TEM images illustrated the distinctive layers of the core and shell, confirming the successful preparation of these fibers. Differential scanning calorimetry (DSC) and X-ray diffraction (XRD) studies confirmed that both drugs were amorphously distributed within the drug-loaded fibers. The drug-loaded fibers exhibited a disintegration time of 2 s, which accelerated the release of both drugs (50% after 5 min) making it an attractive formulation for oral mucosal delivery. The ex vivo permeability study demonstrated that QUE was permeated through the buccal membrane, but not ESC that might be hindered by the buccal epithelium and the intercellular lipids. Overall, the developed coaxial fibers could be a potential buccal dosage form that could be attributed to higher acceptability and adherence among vulnerable patients, particularly mentally ill patients.

Electrospinning for drug delivery applications: A review

Drug delivery devices are promising tools in the pharmaceutical field, as they are able to maximize the therapeutic effects of the delivered drug while minimizing the undesired side effects. In the past years, electrospun nanofibers attracted rising attention due to their unique features, like biocompatibility and broad flexibility. Incorporation of active principles in nanofibrous meshes proved to be an efficient method for in situ delivery of a wide range of drugs, expanding the possibility and applicability of those devices. In this review, the principle of electrospinning and different fields of applications are treated to give an overview of the recent literature, underlining the easy tuning and endless combination of this technique, that in the future could be the new frontier of personalized medicine.

In vitro and in vivo biological assessment of dual drug-loaded coaxial nanofibers for the treatment of corneal abrasion

The treatment of corneal abrasion currently involves the topical administration of antibiotics, with moxifloxacin HCl (0.5% w/v) eye drops being one of the most widely used treatments. Our previous work (Tawfik et al., 2020) involved the development of coaxial poly-lactic-co-glycolic acid (PLGA) and polyvinylpyrrolidone (PVP) nanofibers loaded with the antibiotic moxifloxacin HCl and the anti-scarring agent pirfenidone in the core (PVP) and shell (PLGA) respectively, with a view to the system comprising an ocular insert for the combination therapy of corneal abrasion. In this study, we examine the antimicrobial, anti-scarring and pharmacokinetic properties of the fibers alongside consideration of their toxicity and propensity for irritation. Minimum inhibitory concentration and zone of inhibition studies against S. aureus and P. aeruginosa were performed, while fibroblast cell viability and α-smooth muscle actin (α-SMA, a biomarker for scar formation) were measured using MTT and Western Blot assays, respectively. Pharmacokinetic studies and efficacy against infection were performed using a rabbit model, while ocular irritancy was assessed using the Draize test. The studies demonstrated that the antimicrobial activity of the moxifloxacin HCl was preserved following encapsulation into the nanofibers, while the downregulation of α-SMA was demonstrated using concentrations below the IC₂₀ values (concentration required to decrease corneal fibroblast viability by no more than 20%). The pharmacokinetic study showed retention and sustained release of the moxifloxacin HCl over a 24-hour period, in contrast to equivalent eye drops which required four times daily dosing. Evidence of low level (according to the MMTS scale) irritation was detected for the nanofiber systems. Overall, the study has demonstrated that the dual drug-loaded nanofiber system shows potential for once daily dosing as an ocular insert for the treatment of corneal abrasion.

Core-shell chitosan/PVA-based nanofibrous scaffolds loaded with Satureja mutica or Oliveria decumbens essential oils as enhanced antimicrobial wound dressing

Wounds are prone to bacterial infections, which cause a delayed healing process. Regarding the emergence of bacterial resistance to common antibiotics, using natural antimicrobial agents can be beneficial. Chitosan is a biological polymer, which has shown partial antioxidant and antimicrobial activities. In this study, core-shell nanofibrous scaffolds composed of chitosan (CS)/polyvinyl alcohol (PVA) as the core and polyvinylpyrrolidone (PVP)/ maltodextrin (MD) as the shell were developed. Satureja mutica (S. mutica) or Oliveria decumbens (O. decumbens) essential oil (EO) was encapsulated into the core of the produced scaffolds. The broth microdilution analysis showed significant antimicrobial activity of the EOs. The SEM analysis indicated that the unloaded and loaded core-shell scaffolds with S. mutica or O. decumbens EO had a uniform, beadless structure with fiber mean diameters of 210 ± 50, 250 ± 45, and 225 ± 46 nm, respectively. The CS/PVA-PVP/MD and CS/PVA/EO-PVP/MD scaffolds indicated suitable mechanical properties. The addition of the studied EOs enhanced the antioxidant activity of the scaffolds. The antimicrobial test of produced scaffolds showed that loading of 10% S. mutica or O. decumbens EO could broaden the microbicidal activity of the CS/PVA-PVP/MD scaffolds. These results revealed that the CS/PVA/EO-PVP/MD nanofibrous scaffolds are promising candidates for wound dressing.

A Potential Alternative Orodispersible Formulation to Prednisolone Sodium Phosphate Orally Disintegrating Tablets

The orally disintegrating tablet (ODT) has shown vast potential as an alternative oral dosage form to conventional tablets wherein they can disintegrate rapidly (≤30 s) upon contact with saliva fluid and should have an acceptable mouthfeel as long as their weight doesn’t exceed 500 mg. However, owing to the bitterness of several active ingredients, there is a need to find a suitable alternative to ODTs that maintains their features and can be taste-masked more simply and inexpensively. Therefore, electrospun nanofibers and solvent-cast oral dispersible films (ODFs) are used in this study as potential OD formulations for prednisolone sodium phosphate (PSP) that is commercially available as ODTs. The encapsulation efficiency (EE%) of the ODFs was higher (≈100%) compared to the nanofibers (≈87%), while the disintegration time was considerably faster for the electrospun nanofibers (≈30 s) than the solvent-cast ODFs (≈700 s). Hence, accelerated release rate of PSP from the nanofibers was obtained, due to their higher surface area and characteristic surface morphology that permitted higher wettability and thus, faster erosion. Taste-assessment study using the electronic-tongue quantified the bitterness threshold of the drug and its aversiveness concentration (2.79 mM). Therefore, a taste-masking strategy would be useful when further formulating PSP as an OD formulation.

The Delivery of the Novel Drug 'Halicin' Using Electrospun Fibers for the Treatment of Pressure Ulcer against Pathogenic Bacteria

Pressure ulcer or bedsore is a form of skin infection that commonly occurs with patients admitted to the hospital for an extended period of time, which might lead to severe complications in the absence of medical attention, resulting in infection either by drug-sensitive or drug-resistant bacteria. Halicin, a newly discovered drug effective against several bacterial strains, including multidrug-resistant bacteria, was investigated to reduce bacterial infection burden. This study aims to formulate halicin into electrospun fibers to be applied in bedsores as antibacterial dressing to assess its efficacy against gram-positive (Staphylococcus aureus) and gram-negative bacteria (Escherichia coli and Acinetobacter baumannii) by studying the minimum inhibitory concentration (MIC) and bacterial zone of inhibition assays. The diameters of inhibition growth zones were measured, and the results have shown that the drug-loaded fibers were able to inhibit the growth of bacteria compared to the halicin discs. The release profile of the drug-loaded fibers exhibited a complete release of the drug after 2 h. The results demonstrated that the drug-loaded fibers could successfully release the drug while retaining their biological activity and they may be used as a potential antimicrobial dressing for patients with pressure ulcers caused by multidrug resistant bacteria.

Application of blocking and immobilization of electrospun fiber in the biomedical field

The fiber obtained by electrospinning technology is a kind of biomaterial with excellent properties, which not only has a unique micro-nanostructure that gives it a large specific surface area and porosity, but also has satisfactory biocompatibility and degradability (if the spinning material used is a degradable polymer). These biomaterials provide a suitable place for cell attachment and proliferation, and can also achieve immobilization. On the other hand, its large porosity and three-dimensional spatial structure show unique blocking properties in drug delivery applications in order to achieve the purpose of slow release or even controlled release. The immobilization effect or blocking effect of these materials is mainly reflected in the hollow or core-shell structure. The purpose of this paper is to understand the application of the electrospun fiber based on biodegradable polymers (aliphatic polyesters) in the biomedical field, especially the immobilization or blocking effect of the electrospun fiber membrane on cells, drugs or enzymes. This paper focuses on the performance of these materials in tissue engineering, wound dressing, drug delivery system, and enzyme immobilization technology. Finally, based on the existing research basis of the electrospun fiber in the biomedical field, a potential research direction in the future is put forward, and few suggestions are also given for the technical problems that urgently need to be solved.