Electrospinning for drug delivery applications: A review

Mechanically reinforced hydrogel vehicle delivering angiogenic factor for beta cell therapy

Type 1 diabetes mellitus (T1DM) is a chronic disease affecting millions worldwide. Insulin therapy is currently the golden standard for treating T1DM; however, it does not restore the normal glycaemic balance entirely, which increases the risk of secondary complications. Beta-cell therapy may be a possible way of curing T1DM and has already shown promising results in the clinic. However, low retention rates, poor cell survival, and limited therapeutic potential are ongoing challenges, thus increasing the need for better cell encapsulation devices. This study aimed to develop a mechanically reinforced vascular endothelial growth factor (VEGF)-delivering encapsulation device suitable for beta cell encapsulation and transplantation. Poly(l-lactide-co-ε-caprolactone) (PLCL)/gelatin methacryloyl (GelMA)/alginate coaxial nanofibres were produced using electrospinning and embedded in an alginate hydrogel. The encapsulation device was physically and biologically characterised and was found to be suitable for INS-1E beta cell encapsulation, vascularization, and transplantation in terms of its biocompatibility, porosity, swelling ratio and mechanical properties. Lastly, VEGF was incorporated into the hydrogel and the release kinetics and functional studies revealed a sustained release of bioactive VEGF for at least 14 days, making the modified alginate system a promising candidate for improving the beta cell survival after transplantation.

Electrospun Fibers Loaded with Probiotics: Fundamentals, Characterization, and Applications

Increasing demand for safe, efficient, and eco-friendly solutions for pharmaceutical and food industries has led researchers to explore new approaches to bacterial storage. Several advantages make electrospinning (ES) a promising technique for food systems, including simple manufacturing equipment, a relatively low spinning cost, a wide variety of spinnable materials, and a mild process that is easily controlled, which allows continuous fabrication of ultrafine polymeric fibers at submicron or nanoscales without high temperatures or high pressures. This review briefly describes recent advances in the development of electrospun fibers for loading probiotics (PRB) by focusing on ES technology, its efficiency for loading PRB into fibers (viability, digestive stability, growth rate, release, thermal stability, and interactions of fibers with PRB), and the application of PRB-loaded fibers as active packaging (spoilage/microbial control, antioxidant effect, shelf life). Based on the literature reviewed, the incorporation of PRB into electrospun fibers is both feasible and functional. However, several studies have been limited to proof-of-principle experiments and the use of model biological products. It is necessary to conduct further research to establish the industrial applicability of PRB-loaded fibers, particularly in the fields of food and medicine.

pH-sensitive release of nitric oxide gas using peptide-graphene co-assembled hybrid nanosheets

Nitric oxide (NO) donating drugs such as organic nitrates have been used to treat cardiovascular diseases for more than a century. These donors primarily produce NO systemically. It is however sometimes desirable to control the amount, location, and time of NO delivery. We present the design of a novel pH-sensitive NO release system that is achieved by the synthesis of dipeptide diphenylalanine (FF) and graphene oxide (GO) co-assembled hybrid nanosheets (termed as FF@GO) through weak molecular interactions. These hybrid nanosheets were characterised by using X-ray diffraction, Raman spectroscopy, Fourier transform infrared spectroscopy, zeta potential measurements, X-ray photoelectron spectroscopy, scanning and transmission electron microscopies. The weak molecular interactions, which include electrostatic, hydrogen bonding and π-π stacking, are pH sensitive due to the presence of carboxylic acid and amine functionalities on GO and the dipeptide building blocks. Herein, we demonstrate that this formulation can be loaded with NO gas with the dipeptide acting as an arresting agent to inhibit NO burst release at neutral pH; however, at acidic pH it is capable of releasing NO at the rate of up to 0.6 μM per minute, comparable to the amount of NO produced by healthy endothelium. In conclusion, the innovative conjugation of dipeptide with graphene can store and release NO gas under physiologically relevant concentrations in a pH-responsive manner. pH responsive NO-releasing organic-inorganic nanohybrids may prove useful for the treatment of cardiovascular diseases and other pathologies.

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.

Boosting antitumor efficacy using docetaxel-loaded nanoplatforms: from cancer therapy to regenerative medicine approaches

The intersection of nanotechnology and pharmacology has revolutionized the delivery and efficacy of chemotherapeutic agents, notably docetaxel, a key drug in cancer treatment. Traditionally limited by poor solubility and significant side effects, docetaxel's therapeutic potential has been significantly enhanced through its incorporation into nanoplatforms, such as nanofibers and nanoparticles. This advancement offers targeted delivery, controlled release, and improved bioavailability, dramatically reducing systemic toxicity and enhancing patient outcomes. Nanofibers provide a versatile scaffold for the controlled release of docetaxel, utilizing techniques like electrospinning to tailor drug release profiles. Nanoparticles, on the other hand, enable precise drug delivery to tumor cells, minimizing damage to healthy tissues through sophisticated encapsulation methods such as nanoprecipitation and emulsion. These nanotechnologies not only improve the pharmacokinetic properties of docetaxel but also open new avenues in regenerative medicine by facilitating targeted therapy and cellular regeneration. This narrative review highlights the transformative impact of docetaxel-loaded nanoplatforms in oncology and beyond, showcasing the potential of nanotechnology to overcome the limitations of traditional chemotherapy and pave the way for future innovations in drug delivery and regenerative therapies. Through these advancements, nanotechnology promises a new era of precision medicine, enhancing the efficacy of cancer treatments while minimizing adverse effects.

Swimming short fibrous nasal drops achieving intraventricular administration

Adequate drug delivery across the blood-brain barrier (BBB) is a critical factor in treating central nervous system (CNS) disorders. Inspired by swimming fish and the microstructure of the nasal cavity, this study is the first to develop swimming short fibrous nasal drops that can directly target the nasal mucosa and swim in the nasal cavity, which can effectively deliver drugs to the brain. Briefly, swimming short fibrous nasal drops with charged controlled drug release were fabricated by electrospinning, homogenization, the π-π conjugation between indole group of fibers, the benzene ring of leucine-rich repeat kinase 2 (LRRK2) inhibitor along with charge-dipole interaction between positively charged poly-lysine (PLL) and negatively charged surface of fibers; this enabled these fibers to stick to nasal mucosa, prolonged the residence time on mucosa, and prevented rapid mucociliary clearance. In vitro, swimming short fibrous nasal drops were biocompatible and inhibited microglial activation by releasing an LRRK2 inhibitor. In vivo, luciferase-labelled swimming short fibrous nasal drops delivered an LRRK2 inhibitor to the brain through the nasal mucosa, alleviating cognitive dysfunction caused by sepsis-associated encephalopathy by inhibiting microglial inflammation and improving synaptic plasticity. Thus, swimming short fibrous nasal drops is a promising strategy for the treatment of CNS diseases.

Design and development of dual drug-loaded nanofibrous inserts for ophthalmic sustained delivery of AMK and VAN: Pharmacokinetic study in rabbit's eye

Bacterial corneal keratitis is a damage to the corneal tissue that if not treated, can cause various complications like severe vision loss or even blindness. Combination therapy with two antibiotics which are effective against Gram-positive and Gram-negative bacteria offers sufficient broad-spectrum antibiotic coverage for the treatment of keratitis. Nanofibers can be a potential carrier in dual drug delivery due to their structural characteristics, specific surface area and high porosity. In order to achieve a sustained delivery of amikacin (AMK) and vancomycin (VAN), the current study designed, assessed, and compared nanofibrous inserts utilizing polyvinyl alcohol (PVA) and polycaprolactone (PCL) as biocompatible polymers. Electrospinning method was utilized to prepare two different formulations, PVA-VAN/AMK and PCL/PVA-VAN/AMK, with 351.8 ± 53.59 nm and 383.85 ± 49 nm diameters, respectively. The nanofibers were simply inserted in the cul-de-sac as a noninvasive approach for in vivo studies. The data obtained from the physicochemical and mechanical properties studies confirmed the suitability of the formulations. Antimicrobial investigations showed the antibacterial properties of synthesized nanofibers against Staphylococcus aureus and Pseudomonas aeruginosa. Both in vitro and animal studies demonstrated sustained drug release of the prepared nanofibers for 120 h. Based on the in vivo findings, the prepared nanofibers' AUC0-120 was found to be 20 to 31 times greater than the VAN and AMK solutions. Considering the results, the nanofibrous inserts can be utilized as an effective and safe system in drug delivery.

A Color-Detectable Vitamin C Controlled-Release System Fabricated Using Electrospinning

This study develops a vitamin C controlled-release system, trackable via color changes as a function of vitamin C release. The system is composed of coaxial microfibers prepared via coaxial electrospinning, with a core of poly(ethylene oxide) (PEO) incorporating vitamin C, and a shell composed of polycaprolactone (PCL) containing polydiacetylene (PDA) as the color-changing material. The shell thickness is controlled by adjusting the amount of PCL ejected during electrospinning, allowing regulation of the release rate of vitamin C. When vitamin C added to PEO penetrates the PCL layer, the color of PDA changes from blue to red, indicating a color change. The results of this study can be applied to devices that require immediate detection of vitamin C release levels.

In Situ Photoactivated Antibacterial and Antioxidant Composite Materials to Promote Bone Repair

Trauma and tumor removal usually cause bone defects; in addition, the related postoperative infection also shall be carefully considered clinically. In this study, polylactic acid (PLLA) composite fibers containing Cerium oxide (CeO2) are first prepared by electrospinning technology. Then, the PLLA/CeO2@PDA/Ag composite materials are successfully prepared by reducing silver ion (Ag+) to nano-silver (AgNPs)  coating in situ and binding AgNPs to the materials surface by mussel structure liked polydopamine (PDA). In the materials, Ag+ can be slowly released in simulated body fluids. Based on the photothermal performance of AgNPs, the photothermal conversion efficiency of the materials is 21%, under NIR 808 nm illumination. The effective photothermal conversion can help materials fighting with E. coli and S. aureus in 3 h, with an antibacterial rate of 100%. Additionally, the sustained Ag+ release contributes to the antibacterial in long term. Meanwhile, the materials can mimic the bio-behavior of superoxide dismutase and catalase in decreasing the singlet oxygen level and removing the excess reactive oxygen species. Furthermore, the materials are beneficial for cell proliferation and osteogenic differentiation in vitro. In this study, a promising bone-regenerated material with high photothermal conversion efficiency and antibacterial and anti-oxidation properties, is successfully constructed.

Synthesis and characterization of mupirocin-LDH/PVA nanofibrous composite as a dual-carrier drug release system

Nowadays, nanofibrous structures based on organic and inorganic materials are considered a drug delivery system for the controlled release of antibiotics and other antibacterial agents. The main goal of this research is a combination of the special properties of nanofibrous structure and Mupirocin-loaded Layered double hydroxide (LDH) to obtain a dual-carrier drug release system to provide long term antibacterial properties in wound healing process. Regards, unloaded layered double hydroxide (LDH) and Mupirocin-loaded LDH, which were synthesized by co-precipitation method, were added to Polyvinyl alcohol (PVA) solution in different mass ratio and electrospun using different processing conditions. The physico-chemical characterizations were performed using SEM, FTIR and tensile strength tests. The biological properties of the fabricated nanocomposites were evaluated using antibacterial test and in vitro cell culturing followed by MTT assay. The SEM results showed a bead-less and uniform morphology of nanofibrous composite containing Mupirocin(2.3 wt%)-LDH(15 wt%)/PVA with an average fiber diameter of about 270 ± 58 nm. According to the release study, the maximum release of the mupirocin drug was about 54 % in the first 6 h. The antibiogram analysis exhibited good antibacterial activity of mupirocin-loaded nanocomposite against both bacteria, especially gram-positive one. Finally, MTT assay approved the biocompatibility of the mupirocin-loaded nanocomposite. Overall, the produced nanofibrous composites would be a promising dual-carrier system for controlled release of antibiotic.

Evaluation of the wound healing efficacy of new antibacterial polymeric nanofiber based on polyethylene oxide coated with copper nanoparticles and defensin peptide: An in-vitro to in-vivo assessment

Objective

Today, designing nanofibers with antibacterial properties using electrospinning technology is one of the attractive approaches for wound healing.

Methods

& analysis: This study aims to fabricate a nanocomposite from polyethylene oxide (PEO) coated with copper nanoparticles (NPs) and defensin peptide with wound healing and antimicrobial properties in different ratios of CuNPs/defensin (2/0 mg), (1.5/0.5 mg), and (1/1 mg) in the fixed contain polymer (98 mg). Then, the nanofiber properties were investigated by SEM, tensile, DSC, and BET analysis. Also, the antibacterial properties against S. aureus and E. coli, antioxidant, and in-vivo wound healing effects and histological analysis of the designed nanocomposites were evaluated in rat models.

Results

Our SEM images showed that CuNPs and defensin were properly coated on the PEO surface. According to the tensile, DSC, and antibacterial analysis results, the most appropriate feature was related to CuNPs/defensin (1.5/0.5 mg), with maximum elasticity, heat resistance, and antibacterial activity. Furthermore, the designed nanocomposites showed the best performance as a wound closure agent by increasing dermis and epidermis volume density, stimulating fibroblast cells and collagen fiber production, and improving skin vessels.

Conclusion

According to our results, PEO nanofibers loaded with CuNPs and defensin have the best potential for wound healing, and they can be used as antibacterial materials in the textile, drug, and medical industries.

An Anthocyanin-Based Eco-Friendly Triboelectric Nanogenerator for pH Monitoring and Energy Harvesting

In recent years, renewable and sustainable triboelectric nanogenerators have attracted attention due to their high energy conversion rate, and enhancing their functionality further contributes to their applicability across various fields. A pH-sensitive triboelectric nanogenerator (pH-TENG) has been prepared by electrostatic spinning technology, with anthocyanin as the pH indicator and environmentally friendly polyvinyl alcohol (PVA) as the substrate. Among many friction-negative materials, the pH-TENG exhibits the best combination with fluorinated ethylene propylene (FEP) and yields an open-circuit voltage of 62 V, a short-circuit current of 370 nA, and a transferred charge of 21.8 nC. At a frequency of 3 Hz, it can charge a 4.7 μF capacitor to 2 V within 45 s, effectively powering a thermometer. Furthermore, the presence of anthocyanin does not affect the pH-TENG's power generation performance and enables the monitoring of a wide range of environmental pH changes, with an ΔE change of 28.8 ± 7.6. Therefore, pH-TENG prepared with environmentally friendly materials can bring new available materials to the biological and medical fields.

Spinning with exosomes: electrospun nanofibers for efficient targeting of stem cell-derived exosomes in tissue regeneration

Electrospinning technique converts polymeric solutions into nanoscale fibers using an electric field and can be used for various biomedical and clinical applications. Extracellular vesicles (EVs) are cell-derived small lipid vesicles enriched with biological cargo (proteins and nucleic acids) potential therapeutic applications. In this review, we discuss extending the scope of electrospinning by incorporating stem cell-derived EVs, particularly exosomes, into nanofibers for their effective delivery to target tissues. The parameters used during the electrospinning of biopolymers limit the stability and functional properties of cellular products. However, with careful consideration of process requirements, these can significantly improve stability, leading to longevity, effectiveness, and sustained and localized release. Electrospun nanofibers are known to encapsulate or surface-adsorb biological payloads such as therapeutic EVs, proteins, enzymes, and nucleic acids. Small EVs, specifically exosomes, have recently attracted the attention of researchers working on regeneration and tissue engineering because of their broad distribution and enormous potential as therapeutic agents. This review focuses on current developments in nanofibers for delivering therapeutic cargo molecules, with a special emphasis on exosomes. It also suggests prospective approaches that can be adapted to safely combine these two nanoscale systems and exponentially enhance their benefits in tissue engineering, medical device coating, and drug delivery applications.

Levofloxacin loaded poly (ethylene oxide)-chitosan/quercetin loaded poly (D,L-lactide-co-glycolide) core-shell electrospun nanofibers for burn wound healing

This study developed a new burn wound dressing based on core-shell nanofibers that co-deliver antibiotic and antioxidant drugs. For this purpose, poly(ethylene oxide) (PEO)-chitosan (CS)/poly(D,L-lactide-co-glycolide) (PLGA) core-shell nanofibers were fabricated through co-axial electrospinning technique. Antibiotic levofloxacin (LEV) and antioxidant quercetin (QS) were incorporated into the core and shell parts of PEO-CS/PLGA nanofibers, respectively. The drugs could bond to the polymer chains through hydrogen bonding, leading to their steady release for 168 h. An in vitro drug release study showed a burst effect followed by sustained release of LEV and QS from the nanofibers due to the Fickian diffusion. The NIH 3T3 fibroblast cell viability of the drug loaded core-shell nanofibers was comparable to that in the control (tissue culture polystyrene) implying biocompatibility of the nanofibers and their cell supportive role. However, there was no significant difference in cell viability between the drug loaded and drug free core-shell nanofibers. According to in vivo experiments, PEO-CS-LEV/PLGA-QS core-shell nanofibers could accelerate the healing process of a burn wound compared to a sterile gauze. Thanks to the synergistic therapeutic effect of LEV and QS, a significantly higher wound closure rate was recorded for the drug loaded core-shell nanofibrous dressing than the drug free nanofibers and control. Conclusively, PEO-CS-LEV/PLGA-QS core-shell nanofibers were shown to be a promising wound healing material that could drive the healing cascade through local co-delivery of LEV and QS to burn wounds.

An Insight into Viscosity and Conductivity in the Formulation of Co-axial Electrospun Carica papaya Leaf Extract

Objective: This research aimed to investigate the application of the coaxial electrospun method for the production of natural extracts (papaya leaf extract) fibre films. This was achieved through utilising different polymers and with a focus on the conductivity and the viscosity of polymer solutions as critical parameters to generate successful fibres. Significance: Electrospinning is a promising trending manufacturing method for incorporating thermolabile herbal extracts using coaxial electrospun features. However, the complexity of the electrospinning process and the feasibility of the product required precise scrutiny. Methods: The electrospinning solution parameters (conductivity and viscosity) were evaluated by employing various ratios of Eudragit L100 (EL100) and Eudragit L100-55 (EL100-55) pre-spinning polymeric blend solutions. The electrospinning process and ambient parameters were optimised. Following that, the in-silico physicochemical properties of phytochemical marker, rutin, were illustrated using SwissADME web tool. Both freeze-dried Carica papaya leaf extract and its produced films were characterised using Scanning Electron Microscopy (SEM), Attenuated Total Reflectance Fourier Transform Infrared (ATR-FTIR), polarised light microscopy, and X-Ray Powder Diffraction (XRPD). Results: The optimal values of conductivity (≈40-44 × 10-4 S/m) and viscosity (≈32-42 × 10-3 Pa·s) were determined for producing evenly distributed and small fibre diameters in SEM images. These parameters significance was highlighted in acquiring and maintaining adequate tangential stress for fibre elongation, which would consequently affect the morphology and diameter of the fibres formed. Conclusion: In conclusion, the solution, process, and ambient parameters are significant in developing natural extracts into films via electrospinning technology, and this includes the promising Carica papaya leaf extract films produced by coaxial electrospinning.

Recent advances of electrospray technique for multiparticulate preparation: Drug delivery applications

The electrospray (ES) technique has proven to be an effective and a versatile approach for crafting drug delivery carriers with diverse dimensions, multiple layers, and varying morphologies. Achieving the desired particle properties necessitates careful optimization of various experimental parameters. This review delves into the most prevalent ES system configurations employed for this purpose, such as monoaxial, coaxial, triaxial, and multi-needle setups with solid or liquid collector. In addition, this work underscores the significance of ES in drug delivery carriers and its remarkable ability to encapsulate a wide spectrum of therapeutic agents, including drugs, nucleic acids, proteins, genes and cells. Depth examination of the critical parameters governing the ES process, including the choice of polymer, surface tension, voltage settings, needle size, flow rate, collector types, and the collector distance was conducted with highlighting on their implications on particle characteristics, encompassing morphology, size distribution, and drug encapsulation efficiency. These insights illuminate ES's adaptability in customizing drug delivery systems. To conclude, this review discusses ES process optimization strategies, advantages, limitations and future directions, providing valuable guidance for researchers and practitioners navigating the dynamic landscape of modern drug delivery systems.

Electrospun Materials Based on Cellulose Acetate Loaded with Rosmarinic Acid with Antioxidant and Antifungal Properties

Fibrous cellulose acetate (CA) materials loaded with rosmarinic acid (RA) were successfully created by one-pot electrospinning. In order to improve the water solubility of the polyphenolic acid and to facilitate its release from the fibrous materials, the non-ionic water-soluble polyethylene glycol (PEG) was added. Detailed characterization of the fabricated fibrous CA/RA and CA/PEG/RA materials was performed using scanning electron microscopy (SEM), X-ray diffraction analysis (XRD), UV-Vis spectroscopy and water contact angle analysis. The optimal ratio between CA, RA and PEG for preparation of defect-free and uniform fibers was accomplished by varying their concentrations. Furthermore, the incorporation of the PEG improved the hydrophilicity and wettability of the fibrous CA materials. Moreover, PEG facilitated the RA release and over 360 min, the amount released from fibrous CA/PEG/RA fibers was 91%, while that released from CA/RA materials was 53%. Both of the RA-containing fibrous materials, with and without PEG, manifested high antioxidant activity as determined by the DPPH free radical-scavenging method. In addition, the electrospun CA/PEG/RA materials displayed good antifungal activity against C. albicans. These features make the fibrous CA/PEG/RA materials promising candidates for treatment of wound infections.

Exploring Electrospun Scaffold Innovations in Cardiovascular Therapy: A Review of Electrospinning in Cardiovascular Disease

Cardiovascular disease (CVD) remains the leading cause of mortality worldwide. In particular, patients who suffer from ischemic heart disease (IHD) that is not amenable to surgical or percutaneous revascularization techniques have limited treatment options. Furthermore, after revascularization is successfully implemented, there are a number of pathophysiological changes to the myocardium, including but not limited to ischemia-reperfusion injury, necrosis, altered inflammation, tissue remodeling, and dyskinetic wall motion. Electrospinning, a nanofiber scaffold fabrication technique, has recently emerged as an attractive option as a potential therapeutic platform for the treatment of cardiovascular disease. Electrospun scaffolds made of biocompatible materials have the ability to mimic the native extracellular matrix and are compatible with drug delivery. These inherent properties, combined with ease of customization and a low cost of production, have made electrospun scaffolds an active area of research for the treatment of cardiovascular disease. In this review, we aim to discuss the current state of electrospinning from the fundamentals of scaffold creation to the current role of electrospun materials as both bioengineered extracellular matrices and drug delivery vehicles in the treatment of CVD, with a special emphasis on the potential clinical applications in myocardial ischemia.

The Construction of Three-Layered Biomimetic Arterial Graft Balances Biomechanics and Biocompatibility for Dynamic Biological Reconstruction

The process of reconstructing an arterial graft is a complex and dynamic process that is subject to the influence of various mechanical factors, including tissue regeneration and blood pressure. The attainment of favorable remodeling outcomes is contingent upon the biocompatibility and biomechanical properties of the arterial graft. A promising strategy involves the emulation of the three-layer structure of the native artery, wherein the inner layer is composed of polycaprolactone (PCL) fibers aligned with blood flow, exhibiting excellent biocompatibility that fosters endothelial cell growth and effectively prevents platelet adhesion. The middle layer, consisting of PCL and polyurethane (PU), offers mechanical support and stability by forming a contractile smooth muscle ring and antiexpansion PU network. The outer layer, composed of PCL fibers with an irregular arrangement, promotes the growth of nerves and pericytes for long-term vascular function. Prioritizing the reconstruction of the inner and outer layers establishes a stable environment for intermediate smooth muscle growth. Our three-layer arterial graft is designed to provide the blood vessel with mechanical support and stability through nondegradable PU, while the incorporation of degradable PCL generates potential spaces for tissue ingrowth, thereby transforming our graft into a living implant.

Evaluating the protective effects of dexamethasone and electrospun mesh combination on primary human mixed retinal cells under hyperglycemic stress

Chronic inflammation is a leading cause of neurodegeneration and vision loss in hyperglycemia-associated conditions such as diabetic retinopathy. Corticosteroid injections are widely used for treatment but suffer from limitations such as rapid drug clearance, short drug half-lives and frequent administration. While drug release from biomaterial carriers can overcome these shortcomings, evaluating the combined effects of corticosteroids and polymeric matrices under hyperglycemic stress is an important step towards aiding translation. In this study, we investigated the effects of dexamethasone (DEX) and electrospun mesh combination on primary human mixed retinal cells under normal and hyperglycemic culture conditions. DEX-incorporated poly(lactide-co-glycolide) (PLGA) meshes were prepared and characterized for architecture, chemistry, drug distribution and in vitro release. The meshes exhibited cumulative in vitro drug release of 39.5 % over 2 months at a near constant rate. Under normal culture conditions, DEX-PLGA meshes promoted significantly higher viability of mixed retinal cells than the control groups but without adverse phenotypic activation. Under hyperglycemic conditions, DEX supplementation resulted in higher viability than the control, although the highest viability was achieved only when DEX was added to cells cultured on PLGA fibers. The combination of DEX and PLGA fibers also promoted higher mRNA expression of the antioxidant GSH under hyperglycemia. Importantly, the largest reduction in the production of pro-inflammatory cytokines viz., MMP-9, IL-6, IL-8 and VEGF-R1 was observed for the DEX and PLGA combination. Our study reveals a combined effect of DEX and electrospun fibers in combating hyperglycemia-driven pro-inflammatory responses, which can aid the development of DEX-loaded electrospun implants for diabetes-driven retinal conditions.

Electrospinning technologies for the delivery of Biopharmaceuticals: Current status and future trends

This review provides an in-depth exploration of electrospinning techniques employed to produce micro- or nanofibres of biopharmaceuticals using polymeric solutions or melts with high-voltage electricity. Distinct from prior reviews, the current work narrows its focus on the recent developments and advanced applications in biopharmaceutical formulations. It begins with an overview of electrospinning principles, covering both solution and melt modes. Various methods for incorporating biopharmaceuticals into electrospun fibres, such as surface adsorption, blending, emulsion, co-axial, and high-throughput electrospinning, are elaborated. The review also surveys a wide array of biopharmaceuticals formulated through electrospinning, thereby identifying both opportunities and challenges in this emerging field. Moreover, it outlines the analytical techniques for characterizing electrospun fibres and discusses the legal and regulatory requirements for their production. This work aims to offer valuable insights into the evolving realm of electrospun biopharmaceutical delivery systems.

Switchable surface and loading/release of target molecules in hierarchically porous PLA nonwovens based on shape memory effect

In this work, hierarchically porous PLA (polylactic acid) shape memory nonwovens were prepared by electrospinning its blend solution with PEO (polyethylene oxide) and subsequent water etching. Based on shape memory effect resulting from tiny crystals and the amorphous matrix of PLA, the switch between compact and porous surfaces has been achieved via cyclical hot-pressing and recovery in a hot water bath. After hot-pressing, the disappearance of hierarchical pores contributes to compact surface, enabling embedding of the target molecule in PLA nonwoven (i.e., CLOSE state). Upon exposure to heat, PLA nonwoven recovers to its permanent shape and exhibits a porous surface, providing a penetrative diffusion pathway for small molecules (i.e., OPEN state). The hierarchically porous structure and shape memory effect endow PLA nonwoven with the capability of rapid release. Our results provide a good candidate for some potential applications, such as temperature-controlled quick-release of catalysts and drugs.

Construction of antibacterial bone implants and their application in bone regeneration

Bacterial infection represents a prevalent challenge during the bone repair process, often resulting in implant failure. However, the extensive use of antibiotics has limited local antibacterial effects at the infection site and is prone to side effects. In order to address the issue of bacterial infection during the transplantation of bone implants, four types of bone scaffold implants with long-term antimicrobial functionality have been constructed, including direct contact antimicrobial scaffold, dissolution-penetration antimicrobial scaffold, photocatalytic antimicrobial scaffold, and multimodal synergistic antimicrobial scaffold. The direct contact antimicrobial scaffold involves the physical penetration or disruption of bacterial cell membranes by the scaffold surface or hindrance of bacterial adhesion through surface charge, microstructure, and other factors. The dissolution-penetration antimicrobial scaffold releases antimicrobial substances from the scaffold's interior through degradation and other means to achieve local antimicrobial effects. The photocatalytic antimicrobial scaffold utilizes the absorption of light to generate reactive oxygen species (ROS) with enhanced chemical reactivity for antimicrobial activity. ROS can cause damage to bacterial cell membranes, deoxyribonucleic acid (DNA), proteins, and other components. The multimodal synergistic antimicrobial scaffold involves the combined use of multiple antimicrobial methods to achieve synergistic effects and effectively overcome the limitations of individual antimicrobial approaches. Additionally, the biocompatibility issues of the antimicrobial bone scaffold are also discussed, including in vitro cell adhesion, proliferation, and osteogenic differentiation, as well as in vivo bone repair and vascularization. Finally, the challenges and prospects of antimicrobial bone implants are summarized. The development of antimicrobial bone implants can provide effective solutions to bacterial infection issues in bone defect repair in the foreseeable future.

Electrospun polydioxanone/fucoidan blend nanofibers loaded with anti-cancer precipitate from Jaspis diastra and paclitaxel: Physico-chemical characterization and in-vitro screening

Nanofibers for drug delivery systems have gained much attention during the past years. This paper describes for the first time the loading of a bioactive precipitate (JAD) from the marine sponge Jaspis diastra in PDX and fucoidan-PDX. JAD was characterized by LC-MS/MS and the major component was jaspamide (1) with a purity of 62.66 %. The cytotoxicity of JAD was compared with paclitaxel (PTX). JAD and PTX displayed IC50 values of 1.10 ± 0.7 μg/mL and 0.21 ± 0.12 μg/mL on skin fibroblasts L929 cells whilst their IC50 values on uveal MP41 cancer cells, were 2.10 ± 0.55 μg/mL and 1.38 ± 0.68 μg/mL, respectively. JAD was found to be less cytotoxic to healthy fibroblasts compared to PTX. JAD and PTX loaded scaffolds showed sustained release over 96 h in physiological medium which is likely to reduce the secondary cytotoxic effect induced by JAD and PTX alone. The physico-chemical properties of the loaded and unloaded scaffolds together with their degradation and action on tumor microenvironment by using L929 and MP41 cells were investigated. JAD and PTX at a concentration of 0.5 % (drug/polymer, w/w) in the electrospun mats prevented growth and proliferation of L929 and MP41 cells. Co-culture of L929 and MP41 showed that the JAD and PTX loaded mats inhibited the growth of both cells and caused cell death.

Mesoporous silica nanoparticles accommodating electrospun nanofibers as implantable local drug delivery system processed by cold atmospheric plasma and spin coating approaches

Nanofibers (NF) and nanoparticles are attractive for drug delivery to improve the drug bioavailability and administration. Easy manipulation of NF as macroscopic bulk material give rise to potential usages as implantable local drug delivery systems (LLDS) to overcome the failures of systemic drug delivery systems such as unmet personalized needs, side effects, suboptimal dosage. In this study, poly(ethylene glycol) polyethyleneimine (mPEG:PEI) copolymer blended polyϵ-caprolactone NFs, NFblendaccommodating mesoporous silica nanoparticles (MSN) as the implantable LLDS was achieved by employing spin coating and cold atmospheric plasma (CAP) as the post-process for accommodation on NFblend. The macroporous morphology, mechanical properties, wettability, andin vitrocytocompatibility of NFblendensured their potential as an implantable LLDS and superior features compared to neat NF. The electron microscopy images affirmed of NFblendrandom fiber (average diameter 832 ± 321 nm) alignments and accessible macropores before and after MSN@Cur accommodation. The blending of polymers improved the elongation of NF and the tensile strength which is attributed as beneficial for implantable LLDS. CAP treatment could significantly improve the wettability of NF observed by the contact angle changes from ∼126° to ∼50° which is critical for the accommodation of curcumin-loaded MSN (MSN@Cur) andin vitrocytocompatibility of NF. The combined CAP and spin coating as the post-processes was employed for accommodating MSN@Cur on NFblendwithout interfering with the electrospinning process. The post-processing aided fine-tuning of curcumin dosing (∼3 µg to ∼15 µg) per dose unit and sustained zero-order drug release profile could be achieved. Introducing of MSN@Cur to cells via LLDS promoted the cell proliferation compared to MSN@Cur suspension treatments and assigned as the elimination of adverse effects by nanocarriers by the dosage form integration. All in all, NFblend-MSN@Cur was shown to have high potential to be employed as an implantable LLDS. To the best of our knowledge, this is the first study in which mPEG:PEI copolymer blend NF are united with CAP and spin coating for accommodating nano-drug carriers, which allows for NF both tissue engineering and drug delivery applications.

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

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

Preparation of PCL/lecithin/bacteriocin CAMT6 antimicrobial and antioxidant nanofiber films using emulsion electrospinning: Characteristics and application in chilled salmon preservation

Multi-functional packaging materials are an important development for food preservation. Emulsion electrospinning is a novel and simple method that can be used to prepare multi-functional packaging materials, which can effectively protect the loaded active substances during the preparation process. In this study, PCL/lecithin/bacteriocin CAMT6 nanofiber films with antimicrobial and antioxidant activity were prepared by emulsion electrostatic spinning. The morphology and homogeneity of the prepared nanofibrous membranes could be improved by optimising the formulation of the emulsion for electrospinning. Analytical testing of the prepared nanofiber films revealed that the nanofibers had a core-shell structure, with bacteriocin CAMT6 effectively encapsulated in the core layer and the PCL and phospholipids homogeneously mixed to form the shell layer. Additionally, the nanofiber films had acceptable tensile properties and water absorption capacity. In chilled salmon meat, the nanofiber film effectively inhibited the growth of bacteria, slowed the oxidation of oil and slowed water loss, which was a good protective effect. This study provides a reference for the encapsulation application of food-active packaging materials and bacteriocins.

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

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

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

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

Nano-Micro Core-Shell Fibers for Efficient Pest Trapping

Insect sex pheromones as an alternative to chemical pesticides hold promising prospects in pest control. However, their burst release and duration need to be optimized. Herein, pheromone-loaded core-shell fibers composed of degradable polycaprolactone and polyhydroxybutyrate were prepared by coaxial electrospinning. The results showed that this core-shell fiber had good hydrophobic performance and thermal stability, and the light transmittance in the ultraviolet band was only below 40%, which provided protection to pheromones. The core-shell structure alleviated the burst release of pheromone in the fiber and extended the release time to about 133 days. In the field, the pheromone-loaded core-shell fibers showed the same continuous and efficient trapping of Spodoptera litura as the commercial carriers. More importantly, the electrospun fibers combined with biomaterials had a degradability unmatched by commercial carriers. The structure design strategy provides ideas for the innovative design of pheromone carriers and is a potential tool for the management of agricultural pests.

Overview of Tissue Engineering and Drug Delivery Applications of Reactive Electrospinning and Crosslinking Techniques of Polymeric Nanofibers with Highlights on Their Biocompatibility Testing and Regulatory Aspects

Traditional electrospinning is a promising technique for fabricating nanofibers for tissue engineering and drug delivery applications. The method is highly efficient in producing nanofibers with morphology and porosity similar to the extracellular matrix. Nonetheless, and in many instances, the process has faced several limitations, including weak mechanical strength, large diameter distributions, and scaling-up difficulties of its fabricated electrospun nanofibers. The constraints of the polymer solution's intrinsic properties are primarily responsible for these limitations. Reactive electrospinning constitutes a novel and modified electrospinning techniques developed to overcome those challenges and improve the properties of the fabricated fibers intended for various biomedical applications. This review mainly addresses reactive electrospinning techniques, a relatively new approach for making in situ or post-crosslinked nanofibers. It provides an overview of and discusses the recent literature about chemical and photoreactive electrospinning, their various techniques, their biomedical applications, and FDA regulatory aspects related to their approval and marketing. Another aspect highlighted in this review is the use of crosslinking and reactive electrospinning techniques to enhance the fabricated nanofibers' physicochemical and mechanical properties and make them more biocompatible and tailored for advanced intelligent drug delivery and tissue engineering applications.

Multifunctional Electrospun Nanofibers for Biosensing and Biomedical Engineering Applications

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

Electrospun Nanofiber Scaffolds Loaded with Metal-Based Nanoparticles for Wound Healing

Failures of wound healing have been a focus of research worldwide. With the continuous development of materials science, electrospun nanofiber scaffolds loaded with metal-based nanoparticles provide new ideas and methods for research into new tissue engineering materials due to their excellent antibacterial, anti-inflammatory, and wound healing abilities. In this review, the stages of extracellular matrix and wound healing, electrospun nanofiber scaffolds, metal-based nanoparticles, and metal-based nanoparticles supported by electrospun nanofiber scaffolds are reviewed, and their characteristics and applications are introduced. We discuss in detail the current research on wound healing of metal-based nanoparticles and electrospun nanofiber scaffolds loaded with metal-based nanoparticles, and we highlight the potential mechanisms and promising applications of these scaffolds for promoting wound healing.

Construction of protein-, polysaccharide- and polyphenol-based conjugates as delivery systems

Natural polymers, such as polysaccharides and proteins, have been used to prepare several delivery systems owing to their abundance, bioactivity, and biodegradability. They are usually modified or combined with small molecules to form the delivery systems needed to meet different needs in food systems. This paper reviews the interactions of proteins, polysaccharides, and polyphenols in the bulk phase and discusses the design strategies, coupling techniques, and their applications as conjugates in emulsion delivery systems, including traditional, Pickering, multilayer, and high internal-phase emulsions. Furthermore, it explores the prospects of the application of conjugates in food preservation, food development, and nanocarrier development. Currently, there are seven methods for composite delivery systems including the Maillard reaction, carbodiimide cross-linking, alkali treatment, enzymatic cross-linking, free radical induction, genipin cross-linking, and Schiff base chemical cross-linking to prepare binary and ternary conjugates of proteins, polysaccharides, and polyphenols. To design an effective target complex and its delivery system, it is helpful to understand the physicochemical properties of these biomolecules and their interactions in the bulk phase. This review summarizes the knowledge on the interaction of biological complexes in the bulk phase, preparation methods, and the preparation of stable emulsion delivery system.

Architecture of a dual biocompatible platform to immobilize genistin: fabrication with physio-chemical and in vitro evaluation

The design of biocompatible cell culture substrates and electrospun nanofibers can improve cell proliferation and behavior in laboratory conditions for tissue engineering applications in medicine. In this research, genistin was obtained by extracting from soybean meal powder, and then by adding polycaprolactone (PCL), genistin nanocapsules were prepared. For the first time, we used a lipophilic nanophase (encapsulated genistin) coated in a hydrophilic nanophase (gelatin /polyvinyl alcohol) as a dual nanosystem by the electrospinning method. In the approach, the nanofibers mimic the natural extracellular matrix, interact favorably with cells being cultured from one side, and raise the local concentration of a bioactive compound at the cell surface. The encapsulated drug which was inserted in fibers with a loading percentage of 92.01% showed appropriate and significant controlled release using high-performance liquid chromatography (HPLC). To prove the experiments, analysis using an ultraviolet-visible spectrometer (UV-Vis), 1H NMR spectrometer, Fourier transforms infrared spectrometer (FTIR), mechanical test, scanning electron microscope (SEM) and microscope transmission electron microscopy (TEM) was performed. The sample synthesized with 40% drug using the MTT method exhibited remarkable biological effects, viability, and non-toxicity. Additionally, significant proliferation and adhesion on the mouse fibroblast cell line L929 were observed within a 72-h timeframe.

Molecular complexes of drug combinations: A review of cocrystals, salts, coamorphous systems and amorphous solid dispersions

As the advancements in the medical technology and healthcare develop through the years, combinational therapy has evolved to be an important treatment modality in many disease settings, including cancer, cardiovascular disease and infectious diseases. In an effort to alleviate "pill burden" and improve patient compliance, fixed dose combinations (FDCs) have been developed to be used as effective therapeutics. Among all FDCs, the category of drug-drug molecular complexes has been proven an efficient methodology in designing and treating diseases, with many drugs being approved. Among all drug-drug molecular complexes, drug-drug cocrystals, salts, coamorphous systems and solid dispersions have been successfully developed and many have been approved by the FDA. In this review, we dwell deeply into the molecular mechanisms behind the different types of drug-drug molecular complexes, including the key functional groups involved in the intermolecular interactions, the applications of each category of molecular complexes, as well as the advantages and challenges thereof. This comprehensive review provides useful insights into the practical design and manufacture of drug-drug molecular complexes and points out the future direction for the development of new advantageous combinational therapies that benefit more patients.

In vivo anti-obesity efficacy of fucoxanthin/HP-β-CD nanofibers in high-fat diet induced obese mice

Fucoxanthin (Fx) has poor water solubility and bioavailability, which limits its application in the food industry. To improve the physicochemical properties of Fx, hydroxypropyl-β-cyclodextrin (HP-β-CD) encapsulated Fx nanofibers (Fx/HP-β-CD nanofibers) were fabricated via electrospinning without using polymer. Molecular docking analysis showed the Fx/HP-β-CD nanofibers contained Fx and HP-β-CD at 1:2. Morphological analysis revealed the nanofibers were homogeneous without beads, having a diameter around 499 nm. The thermostability of Fx was significantly improved after encapsulationg by HP-β-CD. Animal studies showed that there was a 14% decrease of body weight, 11% white adipose tissue reduction and 9% lower of liver triglyceride for the mice treated with Fx/HP-β-CD nanofibers as compared with that of Fx treated mice. The total cholesterol was reduced by 23% in mice serum after treatment with Fx/HP-β-CD as compared with that of Fx. Interestingly, the Fx/HP-β-CD in this study could attenuate the testicular histopathology in obese mice.

Biodegradable electrospun fibers as sustained-release carriers of insect pheromones for field trapping of Spodoptera litura (Lepidoptera: Noctuidae)

BACKGROUND

Insect pheromones are highly effective and environmentally friendly, and are widely used in the monitoring and trapping of pests. However, many researchers have found that various factors such as ultraviolet light and temperature in the field environment can accelerate the volatilization of pheromones, thus affecting the actual control effect. In recent years, electrospinning technology has demonstrated remarkable potential in the preparation of sustained carriers. Moreover, the utilization of biodegradable materials in electrospinning presents a promising avenue for the advancement of eco-friendly carriers.

RESULTS

In this study, homogeneous and defect-free pheromone carriers were obtained by electrospinning using fully biodegradable polyhydroxybutyrate materials and pheromones of Spodoptera litura. The electrospun fibers with porous structure could continuously release pheromone (the longest can be ≤80 days). They also had low light transmission, hydrophobic protection. More importantly, the pheromone-loaded electrospun fiber carriers showed stable release and good trapping effect in the field. They could trap pests for at least 7 weeks in the field environment without other light stabilizers added.

CONCLUSION

Sustained-release carriers constructed by electrospinning and green materials could improve the efficacy of pheromones and ensure environmental friendliness, and provided a tool for the management of S. litura and other pests and sustainable development of agricultural. © 2023 Society of Chemical Industry.

Electrospun fibers for the treatment of skin diseases

Skin diseases are among the most common diseases in the global population and with the growth of the aging population, they represent an increasing burden to healthcare systems worldwide. Even though they are rarely life-threatening, the suffering for those affected is high due to the visibility and physical discomfort related to these diseases. Typical symptoms of skin diseases include an inflamed, swollen or itchy skin, and therefore, there is a high demand for effective therapy options. In recent years, electrospinning has attracted considerable interest in the field of drug delivery. The technique allows producing multifunctional drug-loaded fibrous patches from various natural and synthetic polymers with fiber diameters in the nano- and micrometer range, suitable for the treatment of a wide variety of skin diseases. The great potential of electrospun fiber patches not only lies in their tunable drug release properties and the possibility to entrap a variety of therapeutic compounds, but they also provide physical and mechanical protection to the impaired skin area, exhibit a high surface area, allow gas exchange, absorb exudate due to their porous structure and are cytocompatible and biodegradable. In the case of wound healing, cell adhesion is promoted due to the resemblance of the electrospun fibers to the structure of the native extracellular matrix. This review gives an overview of the potential applications of electrospun fibers in skin therapy. In addition to the treatment of bacterial, diabetic and burn wounds, focus is placed on inflammatory diseases such as atopic dermatitis and psoriasis, and therapeutic options for the treatment of skin cancer, acne vulgaris and herpes labialis are discussed. While we aim to emphasize the great potential of electrospun fiber patches for the treatment of skin diseases with this review paper, we also highlight challenges and limitations of current research in the field.

Hydrophobic Tetracycline Immobilized in Fibrous Hyaluronan Regulates Adhesive Collagen-Based Hydrogel Stability for Infected Wound Healing

Collagen-based hydrogels have a significant impact on wound healing, but they suffer from structural instability and bacterial invasion in infected wounds. Here, electrospun nanofibers of esterified hyaluronan (HA-Bn/T) are developed to immobilize the hydrophobic antibacterial drug tetracycline by π-π stacking interaction. Dopamine-modified hyaluronan and HA-Bn/T are employed simultaneously to stabilize the structure of collagen-based hydrogel by chemically interweaving the collagen fibril network and decreasing the rate of collagen degradation. This renders it injectable for in situ gelation, with suitable skin adhesion properties and long-lasting drug release capability. This hybridized interwoven hydrogel promotes the proliferation and migration of L929 cells and vascularization in vitro. It presents satisfactory antibacterial ability against Staphylococcus aureus and Escherichia coli. The structure also retains the functional protein environment provided by collagen fiber, inhibits the bacterial environment of infected wounds, and modulates local inflammation, resulting in neovascularization, collagen deposition, and partial follicular regeneration. This strategy offers a new solution for infected wound healing.

Large-Scale Development of Antibacterial Scaffolds: Gentamicin Sulfate-Loaded Biodegradable Nanofibers for Gastrointestinal Applications

The ever-increasing demands of modern medicine drive the development of novel drug delivery materials. In particular, nanofibers are promising for such materials due to their favorable properties. However, most development is still carried out through laboratory techniques that do not allow extensive and reproducible characterization of materials, which slows medical research. In this work, we focus on the large-scale fabrication and testing of specific antibacterial nanofibrous materials to prevent the postoperative complications associated with the occurrence of bacterial infection. Poly-ε-caprolactone with gentamicin sulfate (antibiotic) in different concentrations was electrospun via a needleless device. The amount of antibiotics was proven by elemental analysis, UV spectrophotometry, and HPLC. The cytocompatibility of the materials was verified in vitro according to ISO 10993-5. The cell adhesion and proliferation were assessed after 2, 7, 14, and 21 days using the CCK-8 metabolic assay, fluorescence, and scanning electron microscopy. The tested nanofiber materials supported cell growth. Antibacterial tests were performed to confirm the release of gentamicin sulfate, and its antibacterial properties were proven toward Staphylococcus gallinarum and Escherichia coli bacteria. The effect of ethylene oxide sterilization was also studied. The sterilized nanofibrous layers are cytocompatible while antibacterial and therefore suitable for medical applications.

Tri-Layer Core-Shell Fibers from Coaxial Electrospinning for a Modified Release of Metronidazole

Polymers are the backbone of drug delivery. Electrospinning has greatly enriched the strategies that have been explored for developing novel drug delivery systems using polymers during the past two decades. In this study, four different kinds of polymers, i.e., the water-soluble polymer poly (vinyl alcohol) (PVA), the insoluble polymer poly(ε-caprolactone) (PCL), the insoluble polymer Eudragit RL100 (ERL100) and the pH-sensitive polymer Eudragit S100 (ES100) were successfully converted into types of tri-layer tri-polymer core-shell fibers through bi-fluid coaxial electrospinning. During the coaxial process, the model drug metronidazole (MTD) was loaded into the shell working fluid, which was an emulsion. The micro-formation mechanism of the tri-layer core-shell fibers from the coaxial emulsion electrospinning was proposed. Scanning electron microscope and transmission electron microscope evaluations verified the linear morphology of the resultant fibers and their obvious tri-layer multiple-chamber structures. X-ray diffraction and Fourier transform infrared spectroscopy measurements demonstrated that the drug MTD presented in the fibers in an amorphous state and was compatible with the three polymeric matrices. In vitro dissolution tests verified that the three kinds of polymer could act in a synergistic manner for a prolonged sustained-release profile of MTD in the gut. The drug controlled-release mechanisms were suggested in detail. The protocols reported here pioneer a new route for creating a tri-layer core-shell structure from both aqueous and organic solvents, and a new strategy for developing advanced drug delivery systems with sophisticated drug controlled-release profiles.

Electrospun Nanofibers for Biomedical, Sensing, and Energy Harvesting Functions

The process of electrospinning is over a century old, yet novel material and method achievements, and later the addition of nanomaterials in polymeric solutions, have spurred a significant increase in research innovations with several unique applications. Significant improvements have been achieved in the development of electrospun nanofibrous matrices, which include tailoring compositions of polymers with active agents, surface functionalization with nanoparticles, and encapsulation of functional materials within the nanofibers. Recently, sequentially combining fabrication of nanofibers with 3D printing was reported by our group and the synergistic process offers fiber membrane functionalities having the mechanical strength offered by 3D printed scaffolds. Recent developments in electrospun nanofibers are enumerated here with special emphasis on biomedical technologies, chemical and biological sensing, and energy harvesting aspects in the context of e-textile and tactile sensing. Energy harvesting offers significant advantages in many applications, such as biomedical technologies and critical infrastructure protection by using the concept of finite state machines and edge computing. Many other uses of devices using electrospun nanofibers, either as standalone or conjoined with 3D printed materials, are envisaged. The focus of this review is to highlight selected novel applications in biomedical technologies, chem.-bio sensing, and broadly in energy harvesting for use in internet of things (IoT) devices. The article concludes with a brief projection of the future direction of electrospun nanofibers, limitations, and how synergetic combination of the two processes will open pathways for future discoveries.

Biopolymer- and Natural Fiber-Based Biomimetic Tissues to Realize Smart Cosmeceuticals and Nutraceuticals Using an Innovative Approach

More sustainable and smart cosmeceuticals and nutraceuticals are necessary due to the ecological transition. In this study, a pullulan-based water solution containing chitin nanofibril-nano-lignin (CN-LG) complexes that encapsulate fish collagen polypeptide, allantoin and nicotinamide was electrospun onto a nonwoven substrate made of bamboo fibers to obtain a smart nanostructured bilayer system for releasing active molecules onto the skin or other body tissues. Infrared spectroscopy was used to characterize the composition of the bilayer system before and after rapid washing of the sample with distilled water and liquids mimicking physiological fluids. The viability of keratinocytes was studied as well as the antioxidant activity, protective activity towards UV light, metalloproteinase release of aged fibroblasts and the inhibitor activity against collagen degradation. Immunomodulatory tests were performed to investigate the anti-inflammatory activity of the bilayer system as well as its indirect antimicrobial activity. The results indicate that the bilayer system can be used in the production of innovative sustainable cosmeceuticals. In general, the adopted strategy can be extended to several smart treatments for fast release that can be commercialized as solid products, thus avoiding the use of preservatives and water.

Pressure-Spun Fibrous Surgical Sutures for Localized Antibacterial Delivery: Development, Characterization, and In Vitro Evaluation

Surgical sutures designed to prevent infection are critical in addressing antibiotic-resistant pathogens that cause surgical site infections. Instead of antibiotics, alternative materials such as biocides have been assessed for coating commercially used sutures due to emerging antibiotic resistance concerns worldwide. This study has a new approach to the development of fibrous surgical sutures with the ability to deliver localized antibacterial agents. A new manufacturing process based on pressure spinning was used for the first time in the production of fibrous surgical sutures by physically blending antibacterial triclosan (Tri) agent with poly(lactic-co-glycolic acid) (PLGA) and poly(ethylene oxide) (PEO) polymers. Fibrous surgical sutures with virgin PLGA, virgin PEO, different ratios of PLGA-PEO, and different ratios of Tri-loaded PLGA-PEO fibrous sutures were produced to mimic the FDA- and NICE-approved PLGA-based sutures available in the market and compared for their characteristics. They were also tested simultaneously with commercially available sutures to compare their in vitro biodegradation, antibacterial, drug release, and cytotoxicity properties. After in vitro antibacterial testing for 24 h, sutures having 285 ± 12 μg/mg Tri loading were selected as a model for further testing as they exhibited antibacterial activity against all tested bacteria strains. The selected model of antibacterial fibrous sutures exhibited an initial burst of Tri release within 24 h, followed by a sustained release for the remaining time until the sutures completely degraded within 21 days. The cell viability assay showed that these surgical sutures had no cytotoxic effect on mammalian cells.

Strategies for Development of Synthetic Heart Valve Tissue Engineering Scaffolds

The current clinical solutions, including mechanical and bioprosthetic valves for valvular heart diseases, are plagued by coagulation, calcification, nondurability, and the inability to grow with patients. The tissue engineering approach attempts to resolve these shortcomings by producing heart valve scaffolds that may deliver patients a life-long solution. Heart valve scaffolds serve as a three-dimensional support structure made of biocompatible materials that provide adequate porosity for cell infiltration, and nutrient and waste transport, sponsor cell adhesion, proliferation, and differentiation, and allow for extracellular matrix production that together contributes to the generation of functional neotissue. The foundation of successful heart valve tissue engineering is replicating native heart valve architecture, mechanics, and cellular attributes through appropriate biomaterials and scaffold designs. This article reviews biomaterials, the fabrication of heart valve scaffolds, and their in-vitro and in-vivo evaluations applied for heart valve tissue engineering.

Electrospun fiber-based micro- and nano-system for delivery of high concentrated quercetin to cancer cells

The anticancer potential of quercetin (Q), a plant-derived flavonoid, and underlining molecular mechanisms are widely documented in cellular models in vitro. However, biomedical applications of Q are limited due to its low bioavailability and hydrophilicity. In the present study, the electrospinning approach was used to obtain polylactide (PLA) and PLA and polyethylene oxide (PEO)-based micro- and nanofibers containing Q, namely PLA/Q and PLA/PEO/Q, respectively, in a form of non-woven fabrics. The structure and physico-chemical properties of Q-loaded fibers were characterized by scanning electron and atomic force microscopy (SEM and AFM), X-ray powder diffraction (XRD), differential scanning calorimetry (DSC), goniometry and FTIR and Raman spectroscopy. The anticancer action of PLA/Q and PLA/PEO/Q was revealed using two types of cancer and nine cell lines, namely osteosarcoma (MG-63, U-2 OS, SaOS-2 cells) and breast cancer (SK-BR-3, MCF-7, MDA-MB-231, MDA-MB-468, Hs 578T, and BT-20 cells). The anticancer activity of Q-loaded fibers was more pronounced than the action of free Q. PLA/Q and PLA/PEO/Q promoted cell cycle arrest, oxidative stress and apoptotic cell death that was not overcome by heat shock protein (HSP)-mediated adaptive response. PLA/Q and PLA/PEO/Q were biocompatible and safe, as judged by in vitro testing using normal fibroblasts. We postulate that PLA/Q and PLA/PEO/Q with Q releasing activity can be considered as a novel and more efficient micro- and nano-system to deliver Q and eliminate phenotypically different cancer cells.

Solvent electrospinning amorphous solid dispersions with high itraconazole, celecoxib, mebendazole and fenofibrate drug loading and release potential

In this work, the feasibility of ultra-high drug loaded amorphous solid dispersions (ASDs) for the poorly soluble itraconazole, mebendazole and celecoxib via solvent electrospinning in combination with poly(2-ethyl-2-oxazoline) and fenofibrate in combination with polyvinylpyrrolidone is demonstrated. By lowering the polymer concentration in the electrospinning solution below its individual spinnable limit, ASDs with a drug content of up to 80 wt% are obtained. This is attributed to drug-polymer interactions not being limited by default to hydrogen bonds, as also Van der Waals interactions can result in high drug loadings. The theoretically predicted miscibility by the Flory-Huggins theory is corroborated by the experimental findings based on (modulated) differential scanning calorimetry and x-ray diffraction. Globally, the maximally obtained amorphous drug loadings are higher compared to the loadings found in literature. Additionally, non-sink dissolution tests demonstrate an increase in solubility of up to 50 times compared to their crystalline counterparts. Moreover, due to the lack of precipitation biocompatible PEtOx succeeds in stabilizing the dissolved drug and inhibiting its instant precipitation. The current work thus demonstrates the broader applicability of the electrospinning technique for the production of physically stable ASDs with ultra-high drug loadings, a result which has been validated for several Biopharmaceutics Classification System class II drugs.

Current advances of nanocellulose application in biomedical field

Nanocellulose (NC) is a natural fiber that can be extracted in fibrils or crystals form from different natural sources, including plants, bacteria, and algae. In recent years, nanocellulose has emerged as a sustainable biomaterial for various medicinal applications including drug delivery systems, wound healing, tissue engineering, and antimicrobial treatment due to its biocompatibility, low cytotoxicity, and exceptional water holding capacity for cell immobilization. Many antimicrobial products can be produced due to the chemical functionality of nanocellulose, such disposable antibacterial smart masks for healthcare use. This article discusses comprehensively three types of nanocellulose: cellulose nanocrystals (CNC), cellulose nanofibrils (CNF), and bacterial nanocellulose (BNC) in view of their structural and functional properties, extraction methods, and the distinctive biomedical applications based on the recently published work. On top of that, the biosafety profile and the future perspectives of nanocellulose-based biomaterials have been further discussed in this review.

From Poly(glycerol itaconate) Gels to Novel Nonwoven Materials for Biomedical Applications

Electrospinning is a process that has attracted significant interest in recent years. It provides the opportunity to produce nanofibers that mimic the extracellular matrix. As a result, it is possible to use the nonwovens as scaffolds characterized by high cellular adhesion. This work focused on the synthesis of poly(glycerol itaconate) (PGItc) and preparation of nonwovens based on PGItc gels and polylactide. PGItc gels were synthesized by a reaction between itaconic anhydride and glycerol. The use of a mixture of PGItc and PLA allowed us to obtain a material with different properties than with stand-alone polymers. In this study, we present the influence of the chosen ratios of polymers and the OH/COOH ratio in the synthesized PGItc on the properties of the obtained materials. The addition of PGItc results in hydrophilization of the nonwovens' surface without disrupting the high porosity of the fibrous structure. Spectral and thermal analyzes are presented, along with SEM imagining. The preliminary cytotoxicity research showed that nonwovens were non-cytotoxic materials. It also helped to pre-determine the potential application of PGItc + PLA nonwovens as subcutaneous tissue fillers or drug delivery systems.