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

A one-step method for generating antimicrobial nanofibre meshes via coaxial electrospinning

Respiratory diseases, including influenza, infectious pneumonia, and severe acute respiratory syndrome (SARS), are a leading cause of morbidity and mortality worldwide. The recent COVID-19 pandemic claimed over 6.9 million lives globally. With the possibility of future pandemics, the creation of affordable antimicrobial meshes for protective gear, such as facemasks, is essential. Electrospinning has been a focus for much of this research, but most approaches are complex and expensive, often wasting raw materials by distributing antiviral agents throughout the mesh despite the fact they can only be active if at the fibre surface. Here, we report a low cost and efficient one-step method to produce nanofibre meshes with antimicrobial activity, including against SARS-CoV-2. Cetrimonium bromide (CTAB) was deposited directly onto the surface of polycaprolactone (PCL) fibres by coaxial electrospinning. The CTAB-coated samples have denser meshes with finer nanofibres than non-coated PCL fibres (mean diameter: ∼300 nm versus ∼900 nm, with mean pore size: ∼300 nm versus > 600 nm). The formulations have > 90% coating efficiency and exhibit a burst release of CTAB upon coming into contact with aqueous media. The CTAB-coated materials have strong antibacterial activity against Staphylococcus aureus (ca. 100%) and Pseudomonas aeruginosa (96.5 ± 4.1%) bacteria, as well as potent antiviral activity with over 99.9% efficacy against both respiratory syncytial virus and SARS-CoV-2. The CTAB-coated nanofibre mesh thus has great potential to form a mask material for preventing both bacterial and viral respiratory infections.

An emerging terpolymeric nanoparticle pore former as an internal recrystallization inhibitor of celecoxib in controlled release amorphous solid dispersion beads: Experimental studies and molecular dynamics analysis

Solid oral controlled release formulations feature numerous clinical advantages for drug candidates with adequate solubility and dissolution rate. However, most new chemical entities exhibit poor water solubility, and hence are exempt from such benefits. Although combining drug amorphization with controlled release formulation is promising to elevate drug solubility, like other supersaturating systems, the problem of drug recrystallization has yet to be resolved, particularly within the dosage form. Here, we explored the potential of an emerging, non-leachable terpolymer nanoparticle (TPN) pore former as an internal recrystallization inhibitor within controlled release amorphous solid dispersion (CRASD) beads comprising a poorly soluble drug (celecoxib) reservoir and insoluble polymer (ethylcellulose) membrane. Compared to conventional pore former, polyvinylpyrrolidone (PVP), TPN-containing membranes exhibited superior structural integrity, less crystal formation at the CRASD bead surface, and greater extent of celecoxib release. All-atom molecular dynamics analyses revealed that in the presence of TPN, intra-molecular bonding, crystal formation tendency, diffusion coefficient, and molecular flexibility of celecoxib were reduced, while intermolecular H-bonding was increased as compared to PVP. This work suggests that selection of a pore former that promotes prolonged molecular separation within a nanoporous controlled release membrane structure may serve as an effective strategy to enhance amorphicity preservation inside CRASD.

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

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

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

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

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

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

Ethyl cellulose/gelatin/β-cyclodextrin/curcumin nanofibrous membrane with antibacterial and formaldehyde adsorbable capabilities for lightweight and high-performance air filtration

Functionalization of bio-based nanofibers is the development tendency of high-performance air filter. However, the conventional structural optimization strategy based on high solution conductivity greatly hinders the development of fully bio-based air filter, and not conducive to sustainable development. This work fabricated fully bio-based nanofibrous membrane with formaldehyde-adsorbable and antibacterial capabilities by electrospinning low-conductivity solution for high-performance air filtration and applied to lightweight mask. The "water-like" ethyl cellulose (EC) was selected as the base polymer to "nourish" functional materials of gelatin (GE), β-cyclodextrin (βCD), and curcumin (Cur), thus forming a solution system with high binding energy differences and electrospinning into ultrafine bimodal nanofibers. The filtration efficiency for 0.3 μm NaCl particles, pressure drop, and quality factor were 99.25 %, 53 Pa, and 0.092 Pa-1, respectively; the bacteriostatic rates against Escherichia coli and Staphylococcus aureus were 99.9 % and 99.4 %, respectively; the formaldehyde adsorption capacity was 442 μg/g. This is the first report on antibacterial and formaldehyde-adsorbable high-performance air filter entirely made from bio-based materials. This simple strategy will greatly broaden the selection of materials for preparing high-performance multifunctional air filter, and promote the development of bio-based air filter.

Fabrication of colon-targeted ethyl cellulose/gelatin hybrid nanofibers: Regulation of quercetin release and its anticancer activity

A colon-targeted delivery system that can efficiently deliver and release quercetin is essential to improve its bioavailability. We previously found that hydrophobic ethyl cellulose (EC) nanofibers could efficiently deliver quercetin to colon, but the release of quercetin was limited. To address this problem, hydrophilic gelatin (GN) was used as a regulator, and quercetin-loaded nanofibers with different mass ratios of EC to GN (3:1, 1:1, 1:2, 1:3) were fabricated by electrospinning. All nanofibers had a cylindrical morphology and high encapsulation efficiency (over 94 %), and there existed molecular interactions among quercetin, EC, and GN. The high GN content reduced the thermal stability of nanofibers but increased their surface wettability. Besides, these nanofibers had good stability in acidic and aqueous foods. Importantly, the release of quercetin in the simulated gastrointestinal fluid was <3 %. The addition of GN was beneficial to the release of quercetin in colon, and nanofibers with EC to GN being 1:3 had a more preferable release performance. The anticancer activity of nanofibers against HCT-116 cells was proved by inhibiting cell viability through the induction of apoptosis. Therefore, these nanofibers are potential carriers for efficient colon-targeted delivery of bioactive compounds in the food industry.

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

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

An ecofriendly coaxial antibacterial and anticorrosion nanofiber pullulan-ethyl cellulose embedded with carvacrol coating for protection against marine corrosion

Coaxial electrospun coatings with antibacterial and anticorrosion properties have a marked potential to protect against corrosion in marine environments. Ethyl cellulose is a promising biopolymer for corrosion caused by microorganisms owing to its high mechanical strength, nontoxicity, and biodegradability. In this study, a coaxial electrospun coating loaded with antibacterial carvacrol (CV) in the core and anticorrosion pullulan (Pu) and ethyl cellulose (EC) as a shell layer was successfully fabricated. The formation of core-shell structure was confirmed using transmission electron microscopy. Pu-EC@CV coaxial nanofiber had small diameters, uniform distribution, smooth surface, strong hydrophobicity, and no fractures. Electrochemical impedance spectroscopy was used to analyze corrosion of the electrospun coating surface in a medium containing bacterial solution. The results indicated significant corrosion resistance of the coating surface. In addition, the antibacterial activity and mechanism of coaxial electrospun were studied. The Pu-EC@CV nanofiber coating exhibited excellent antibacterial properties by effectively increasing the permeability of cell membranes and killing bacteria, as determined by plate counts, scanning electron microscopy, cell membrane permeability, and the activity of alkaline phosphatase. In summary, the coaxial electrospun pullulan-ethyl cellulose embedded with CV coating can be used as antibacterial and anticorrosion materials and may have potential applications in the field of marine corrosion.

Green synthesize of nano-MOF-ethylcellulose composite fibers for efficient adsorption of Congo red from water

Two novel MOF- ethyl cellulose (EC)- based nanocomposites have been designed and synthesized in water by electrospinning and applied for adsorption of congo red (CR) in water. Nano- Zeolitic Imidazolate Framework-67 (ZIF-67), and Materials of Institute Lavoisier (MIL-88A) were synthesized in aqueous solutions by a green method. To enhance the dye adsorption capacity and stability of MOFs, they have been incorporated into EC nanofiber to prepare composite adsorbents. The performance of both composites in the absorption of CR, a common pollutant in some industrial wastewaters, has then been investigated. Various parameters including initial dye concentration, the dosage of the adsorbent, pH, temperature and contact time were optimized. The results indicated 99.8 and 90.9% adsorption of CR by EC/ZIF-67 and EC/MIL-88A, respectively at pH = 7 and temperature at 25 °C after 50 min. Furthermore, the synthesized composites were separated conveniently and successfully reused five times without significant loss of their adsorption activity. For both composites, the adsorption behavior can be explained by pseudo-second-order kinetics, Intraparticular diffiusion and Elovich models demonstrated that the experimental data well matched to the pseudo-second-order kinetics. Intraparticular diffiusion model showed that the adsorption of CR on EC/ZIF-67 and EC/MIL-88a took place in one and two steps, respectively. Freundlich isotherm models and thermodynamic analysis indicated exothermic and spontaneous adsorption.

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

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

Development of Nanofibers with Embedded Liposomes Containing an Immunomodulatory Drug Using Green Electrospinning

Conventional treatments for chronic wounds are often ineffective, thus new therapeutic approaches are needed, such as the delivery of immunomodulatory drugs that can reduce inflammation, restore immune cell function, and facilitate tissue regeneration. A potential drug for such an approach is simvastatin, which has major drawbacks including poor solubility and chemical instability. With the aim of developing a dressing for wound healing, simvastatin and an antioxidant were incorporated into alginate/poly(ethylene oxide) nanofibers by green electrospinning without the use of organic solvents, thanks to their prior encapsulation into liposomes. The composite liposome-nanofiber formulations exhibited fibrillar morphology (160-312 nm) and unprecedentedly high phospholipid and drug content (76%). Transmission electron microscopy revealed dried liposomes as bright ellipsoidal spots homogeneously distributed over the nanofibers. After nanofiber hydration, the liposomes reconstituted in two size populations (~140 and ~435 nm), as revealed by cutting-edge MADLS^® analysis. Lastly, in vitro assays demonstrated that composite liposome-nanofiber formulations are superior to liposomal formulations due to a better safety profile in keratinocytes and peripheral blood mononuclear cells. Furthermore, both formulations exhibited similarly advantageous immunomodulatory effects, measured as decreased inflammation in vitro. A synergistic combination of the two nanodelivery systems shows promise for the development of efficient dressings for chronic wound treatment.

Fabrication and characterization of anti-rosacea 3D nanofibrous customized sheet masks as a novel scaffold for repurposed use of spironolactone with pre-clinical studies

The repurposed oral use of spironolactone (SP) as an anti-rosacea drug faces many challenges that hinder its efficacy and compliance. In this study, a topically applied nanofibers (NFs) scaffold was evaluated as a promising nanocarrier that enhances SP activity and avoids the friction routine that exaggerates rosacea patients' inflamed, sensitive skin. SP-loaded poly-vinylpyrrolidone (40% PVP) nanofibers (SP-PVP NFs) were electrospun. Scanning electron microscopy showed that SP-PVP NFs have a smooth homogenous surface with a diameter of about 426.60 nm. Wettability, solid state, and mechanical properties of NFs were evaluated. Encapsulation efficiency and drug loading were 96.34% ± 1.20 and 11.89% ± 0.15, respectively. The in vitro release study showed a higher amount of SP released over pure SP with a controlled release pattern. Ex vivo results showed that the permeated amount of SP from SP-PVP NFs sheets was 4.1 times greater than that of pure SP gel. A higher percentage of SP was retained in different skin layers. Moreover, the in vivo anti-rosacea efficacy of SP-PVP NFs using croton oil challenge showed a significant reduction in erythema score compared to the pure SP. The stability and safety of NFs mats were proved, indicating that SP-PVP NFs are promising carriers of SP.

Enhancement of Release and Solubility of Curcumin from Electrospun PEO-EC-PVP Tripolymer-Based Nanofibers: A Study on the Effect of Hydrogenated Castor Oil

This study reveals the state-of-the-art fabrication of a tripolymer-based electrospun nanofiber (NF) system to enhance the release, solubility, and transdermal penetration of curcumin (Cur) with the aid of in situ release of infused castor oil (Co). In this regard, Cur-loaded Co-infused polyethylene oxide (PEO), ethyl cellulose (EC), and polyvinyl pyrrolidone (PVP) tripolymer-based NF systems were developed to produce a hybridized transdermal skin patch. Weight percentages of 1-4% Cur and 3-10% of Co were blended with PEO-EC-PEO and PEO-EC-PVP polymer systems. The prepared NFs were characterized by SEM, TEM, FT-IR analysis, PXRD, differential scanning calorimetry (DSC), and XPS. Dialysis membranes and vertical Franz diffusion cells were used to study the in vitro drug release and transdermal penetration, respectively. The results indicated that maintaining a Cur concentration of 1-3 wt % with 3 wt % Co in both PEO-EC-Co-Cur@PEO and PEO-EC-Co-Cur@PVP gave rise to nanofibers with lowered diameters (144.83 ± 48.05-209.26 ± 41.80 nm and 190.20 ± 59.42-404.59 ± 45.31 nm). Lowered crystallinity observed from the PXRD patterns and the disappearance of exothermic peaks corresponding to the melting point of Cur suggested the formation of an amorphous NF structure. Furthermore, the XPS data revealed that the Cur loading will possibly take place at the inner interface of PEO-EC-Co-PEO and PEO-EC-Co-PVP NFs rather than on the surface. The beneficiary role of Co on the release and dermal penetration of Cur was further confirmed from the respective release data which indicated that PEO-EC-Co-Cur@PEO would lead to a rapid release (4-5 h), while PEO-EC-Co-Cur@PVP would lead to a sustained release over a period of 24 h in the presence of Co. Transdermal penetration of the released Cur was further evidenced with the development of color in the receiver compartment of the diffusion cell. DPPH results further corroborated that a sustained antioxidant activity is observed in the released Cur where the free-radical scavenging activity is intact even after subjecting to an electrospinning process and under extreme freeze-thaw conditions.

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

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

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

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

Physicomechanical properties and in vitro release behaviors of electrospun ibuprofen-loaded blend PEO/EC fibers

Electrospinning is a fiber manufacturing technique with the possibility of encapsulating high levels of small molecule drugs while providing controlled release rates. In this study, electrospun blend fibers were produced from polyethylene oxide (PEO) and ethyl cellulose (EC) at various compositions to encapsulate a poorly water-soluble drug of ibuprofen (IBP) at 30% loading. Microscopic evaluation showed smooth and defect-free fiber morphologies for blank and IBP-loaded PEO/EC fibers. The average fiber diameters and fiber yields suggested a potential optimization on the blend fiber composition for the electrospun drug-eluting PEO/EC fibers, where the highest average fiber diameter and fiber yield occurred at 50PEO/50EC fiber composition. Surface wettability studies demonstrated the effects on surface hydrophobicity from blend fibers of water-soluble PEO and hydrophobic EC as well as the incorporation of IBP. In addition, blend fibers containing more PEO promoted the water absorption rates through dissolution of the polymer matrix. Furthermore, results from mechanical testing of the blend fibers showed the highest fiber elastic modulus and tensile strength at fiber compositions in between 75PEO/25EC and 50PEO/50EC, corresponding to the average fiber diameter measurements. The in vitro IBP release rates demonstrated a dependence on the EC compositions supported by the surface wettability and water absorption rate studies. In general, our work demonstrated the ability to electrospin blank and IBP-loaded PEO/EC fibers with the scientific understandings of EC compositions on modulations of fiber physicomechanical properties and in vitro drug release rates. The findings from the work indicated the potential engineering and pharmaceutical applications of electrospun drug-eluting fibers for topical drug delivery.

Dissolving microneedle-encapsulated drug-loaded nanoparticles and recombinant humanized collagen type III for the treatment of chronic wound via anti-inflammation and enhanced cell proliferation and angiogenesis

Nowadays, diabetic chronic wounds impose a heavy burden on patients and the medical system. Persistent inflammation and poor tissue remodeling severely limit the healing of chronic wounds. For these issues, the first recombinant humanized collagen type III (rhCol III) and naproxen (Nap) loaded poly(lactic-co-glycolic acid) (PLGA) nanoparticle incorporated hyaluronic acid (HA) microneedle (MN) was fabricated for diabetic chronic wound therapy. As the tailored rhCol III was synthesized based on the Gly483-Pro512 segment, which contained the highly adhesive fragments (GER, GEK) in the human collagen type III sequence, it possessed strong cell adhesion. The mechanical strength of the prepared MN was enough to overcome the tissue barrier of necrosis/hyperkeratosis in a minimally invasive way after being applied in wounds. Subsequently, rhCol III and Nap@PLGA nanoparticles were rapidly released to the wound site within a few minutes. The prepared MN possessed favourable biocompatibility and could effectively facilitate the proliferation and migration of fibroblasts and endothelial cells. Furthermore, the regenerative efficacy of the MN was evaluated in vivo using the diabetic rat full-thickness skin wound model. These results illustrated that the prepared MN could accelerate wound closure by reducing the inflammatory response and enhancing angiogenesis or collagen deposition, indicating their significant application value in wound dressings for chronic wound repair.

Cellulose nanocrystals: Fundamentals and biomedical applications

The present review explores the recent developments of cellulose nanocrystals, a class of captivating nanomaterials in variety of applications. CNCs are made by acid hydrolysing cellulosic materials like wood, cotton, tunicate, flax fibers by sonochemistry. It has many desirable properties, including a high tensile strength, wide surface area, stiffness, exceptional colloidal stability, and the ability to be modified. CNCs are colloidally stable, hydrophilic, and rigid rod-shaped bio-based nanomaterials in the form of rigid rods with high strength and surface area that has a diverse set of applications and properties. The intriguing features emerging from numerous fibers studies, such as renewable character and biodegradability, piqued the curiosity of many researchers who worked on lowering the size of these fibers. Physicochemical properties such as rheological, mechanical, thermal, lipid crystalline, swelling capacity, microstructural properties result in affecting surface-area to volume ratio and crystallinity of cellulose nanocrystals. The present article highlights the fundamentals of cellulose nanocrystals such as sources, isolation, fabrication, properties and surface modification with an emphasis on plethora of biomedical applications. Selected nanocellulose studies with significant findings on cellular labelling and bioimaging, tissue engineering, biosensors, gene delivery, anti-viral property, anti-bacterial property, ocular delivery, modified drug release, anti-cancer activity and enzyme immobilization are emphasized.

An Overview of Cellulose Derivatives-Based Dressings for Wound-Healing Management

Presently, notwithstanding the progress regarding wound-healing management, the treatment of the majority of skin lesions still represents a serious challenge for biomedical and pharmaceutical industries. Thus, the attention of the researchers has turned to the development of novel materials based on cellulose derivatives. Cellulose derivatives are semi-synthetic biopolymers, which exhibit high solubility in water and represent an advantageous alternative to water-insoluble cellulose. These biopolymers possess excellent properties, such as biocompatibility, biodegradability, sustainability, non-toxicity, non-immunogenicity, thermo-gelling behavior, mechanical strength, abundance, low costs, antibacterial effect, and high hydrophilicity. They have an efficient ability to absorb and retain a large quantity of wound exudates in the interstitial sites of their networks and can maintain optimal local moisture. Cellulose derivatives also represent a proper scaffold to incorporate various bioactive agents with beneficial therapeutic effects on skin tissue restoration. Due to these suitable and versatile characteristics, cellulose derivatives are attractive and captivating materials for wound-healing applications. This review presents an extensive overview of recent research regarding promising cellulose derivatives-based materials for the development of multiple biomedical and pharmaceutical applications, such as wound dressings, drug delivery devices, and tissue engineering.

A Recent Update on Drug Delivery Systems for Pain Management

Pain remains a global health challenge affecting approximately 1.5 billion people worldwide. Pain has been an implicit variable in the equation of human life for many centuries considering different types and the magnitude of pain. Therefore, developing an efficacious drug delivery system for pain management remains an open challenge for researchers in the field of medicine. Lack of therapeutic efficacy still persists, despite high throughput studies in the field of pain management. Research scientists have been exploiting different alternatives to curb the adverse side effects of pain medications or attempting a more substantial approach to minimize the prevalence of pain. Various drug delivery systems have been developed such as nanoparticles, microparticles to curb adverse side effects of pain medications or minimize the prevalence of pain. This literature review firstly provides a brief introduction of pain as a sensation and its pharmacological interventions. Second, it highlights the most recent studies in the pharmaceutical field for pain management and serves as a strong base for future developments. Herein, we have classified drug delivery systems based on their sizes such as nano, micro, and macro systems, and for each of the reviewed systems, design, formulation strategies, and drug release performance has been discussed.

Multifunctional Role of Polyvinylpyrrolidone in Pharmaceutical Formulations

Polyvinylpyrrolidone (PVP), a non-ionic polymer, has been employed in multifarious fields such as paper, fibers and textiles, ceramics, and pharmaceutics due to its superior properties. Especially in pharmacy, the properties of inertness, non-toxicity, and biocompatibility make it a versatile excipient for both conventional formulations and novel controlled or targeted delivery systems, serving as a binder, coating agent, suspending agent, pore-former, solubilizer, stabilizer, etc. PVP with different molecular weights (MWs) and concentrations is used in a variety of formulations for different purposes. In this review, PVP-related researches mainly in recent 10 years were collected, and its main pharmaceutical applications were summarized as follows: (i) improving the bioavailability and stability of drugs, (ii) improving the physicomechanical properties of preparations, (iii) adjusting the release rate of drugs, and (iv) prolonging the in vivo circulation time of liposomes. Most of these applications could be explained by the viscosity, solubility, hydrophilicity, and hydrogen bond-forming ability of PVP, and the specific action mechanisms for each application were also tried to figure out. The effect of PVP on bioavailability improvement establishes it as a promising polymer in the emerging controlled or targeted formulations, attracting growing interest on it. Therefore, given its irreplaceability and tremendous opportunities for future developments, this review aims to provide an informative reference about current roles of PVP in pharmacy for interested readers.

Nanofibrous cosmetic face mask for transdermal delivery of nano gold: synthesis, characterization, release and zebra fish employed toxicity studies

This study involves the generation of gold nanoparticles (Au NPs) via a novel natural/non-toxic methodology using tea and orange-peel extracts. These were then embedded into a novel blend composed of a polyethylene oxide and gelatin (PEO-Gel) fibre mat. The scanning electron microscopy results indicated that the addition of both collagen (COL) and ascorbic acid (AA) into the PEO-Gel system (PEO-Gel-AA-COL system) enhances the Au NP incorporation into nanofibres leading to a diameter of 164.60 ± 20.95 and 192.43 ± 39.14 nm in contrast to the spraying observed with the Au PEO-Gel system alone. Releasing studies conducted over 30 min indicated that the PEO-Gel-AA-COL-orange peel Au (OpAu) system accounts for a higher content of Au release than the green tea Au (GtAu) NP system where a maximum release could be attained within 10-30 min depending on the amount of Au NPs that have been incorporated. Moreover, the transdermal diffusion studies conducted using Strat membrane indicated that Au NPs from both formulations (PEO-Gel-AA-COL-GtAu nanofibre, PEO-Gel-AA-COL-OpAu nanofibre) have diffused through the stratum corneum and trapped in the dermis and epidermis indicating its transdermal deliverability. Additionally, 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay revealed that nanofibres have similar radical scavenging activity like AA standard. Toxicity evaluation on a zebra fish embryo model confirmed that both GtAu NPs and OpAu NPs do not induce any teratogenic activity and are safe to be used in the range of 1.0-167 µg ml-1.

Silver sulfadiazine-loaded electrospun ethyl cellulose/polylactic acid/collagen nanofibrous mats with antibacterial properties for wound healing

Recently, the electrospun nanofiber mats with appropriate properties for applications in the biomedical area has been more considered. In this regard, we successfully fabricated a novel antibacterial nanofiber mat (ethyl cellulose/poly lactic acid/collagen) (EC/PLA/collagen) incorporated with silver sulfadiazine (AgSD) and then analyzed with the required tests. AgSD was loaded in the developed mats with different contents (0.25%, 0.5% and 0.75%) and then electrospun to prepare nanofiber mats. To check the chemical structure of the developed mat, Fourier transform infrared spectroscopy (FTIR) was assessed. Surface morphological studies were performed by Scanning Electron Microscopy (SEM), which displayed uniform nanofiber mats without any bead formation. When the hydrophilicity was enhanced by decreasing the blending ratios of EC/PLA, the thermal stability of the nanofibers was reduced. The water contact angle (WCA) of NFs enhanced by decreasing the blending ratios of EC/PLA. The antibacterial properties showed the inhibition activity against Bacillus (9.71 ± 1.15 mm) and E. coli (12.46 ± 1.31 mm) bacteria. Besides, nanofibers have improved cell proliferation and adhesion with any cytotoxic effect on NIH 3T3 fibroblast cells. According these results, it seems that the developed mats would be effective scaffold for application in wound dressings.

Frequency and waveform dependence of alternating current electrospinning and their uses for drug dissolution enhancement

The effect of different frequencies and waveforms was investigated for the first time on alternating current electrospinning (ACES). PVPVA64, a polyvinylpyrrolidone-vinyl acetate copolymer was selected for the experiments as an important matrix for amorphous solid dispersions but never processed with ACES. It has been proved that ACES could be operated in a wide range of frequencies (40-250 Hz) and using different waveforms (sinusoidal, square, triangle, saw tooth) without significant changes in fiber morphology. Nevertheless, deterioration of the fiber formation process could be also observed especially at high frequencies. The developed PVPVA64-based fibers containing small amounts of additives (polyethylene oxide (PEO) and sodium dodecyl sulfate (SDS)) served as an excellent carrier for spironolactone (SPIR), a poorly soluble antihypertensive drug. As a result of the amorphously dispersed SPIR and the large surface area of the AC electrospun fibers immediate drug release could be achieved.

Recent advances in composites based on cellulose derivatives for biomedical applications

Cellulose derivatives represent a viable alternative to pure cellulose due to their solubility in water and common organic solvents. This, coupled with their low cost, biocompatibility, and biodegradability, makes them an attractive choice for applications related to the biomedicine and bioanalysis area. Cellulose derivatives-based composites with improved properties were researched as films and membranes for osseointegration, hemodialysis and biosensors, smart textile fibers, tissue engineering scaffolds, hydrogels and nanoparticles for drug delivery. The different preparation strategies of these polymeric composites as well as the most recent available experimental results were described in this review. General aspects such as structure and properties of cellulose extracted from plants or bacterial sources, types of cellulose derivatives and their synthesis methods were also discussed. Finally, the future perspectives related to composites based on cellulose derivatives were highlighted and some conclusions regarding the reviewed applications were drawn.

Long-Term Effect against Methicillin-Resistant Staphylococcus aureus of Emodin Released from Coaxial Electrospinning Nanofiber Membranes with a Biphasic Profile

Methicillin-resistant Staphylococcus aureus (MRSA) is a serious and rapidly growing threat to human beings. Emodin has a potent activity against MRSA; however, its usage is limited due to high hydrophobicity and low oral bioavailability. Thus, the coaxial electrospinning nanofibers encapsulating emodin in the core of hydrophilic poly (vinylpyrrolidone), with a hygroscopic cellulose acetate sheath, have been fabricated to provide long-term effect against MRSA. Scanning electron microscopy and transmission electron microscopy confirmed the nanofibers had a linear morphology with nanometer in diameter, smooth surface, and core-shell structure. Attenuated total reflection-Fourier transform infrared spectra, X-ray diffraction patterns, and differential scanning calorimetric analyses verified emodin existed in amorphous form in the nanofibers. The nanofibers have 99.38 ± 1.00% entrapment efficiency of emodin and 167.8 ± 0.20% swelling ratio. Emodin released from nanofibers showed a biphasic drug release profile with an initial rapid release followed by a slower sustained release. CCK-8 assays confirmed the nontoxic nature of the emodin-loaded nanofibers to HaCaT cells. The anti-MRSA activity of the nanofibers can persist up to 9 days in AATCC147 and soft-agar overlay assays. These findings suggest that the emodin-loaded electrospun nanofibers with core-shell structure could be used as topical drug delivery system for wound infected by MRSA.

Fabrication and characterization of a novel polysaccharide based composite nanofiber films with tunable physical properties

In this study, the pullulan/ethyl cellulose composite nanofiber films with tunable physical properties were fabricated by blend electrospinning process. The solution properties of polysaccharide polymers were investigated and related with the morphology of the nanofiber films, and the results showed that the addition of ethyl cellulose caused decreasing viscosity and conductivity of solutions, which gave rise to the smaller fiber diameter. The Fourier transform infrared spectroscopy indicated that pullulan and ethyl cellulose chains interacted with each other through hydrogen bonding. X-ray diffraction analysis showed that electrospinning process retarded the crystallization of polysaccharide molecules. Thermal analysis showed that the composite nanofiber films possessed higher melting temperature and degradation temperature than the pure pullulan nanofiber film. Water contact angle and water stability test proved that the composite nanofiber films possessed tunable surface wettability (94.6°-120.1°) and improved water stability. The mechanical test showed that the composite nanofiber films had enhanced mechanical strength.

MOF-derived novel porous Fe3O4@C nanocomposites as smart nanomedical platforms for combined cancer therapy: magnetic-triggered synergistic hyperthermia and chemotherapy

Smart Fe₃O₄@C-PVP@DOX nanomedical platforms hold great potential application in the precise treatments of clinical cancer.

Recent developments in the use of organic-inorganic nanohybrids for drug delivery

Organic-inorganic nanohybrid (OINH) structures providing a versatile platform for drug delivery with improved characteristics are an area which has gained recent attention. Much effort has been taken to develop these structures to provide a viable treatment options for much alarming diseases such as cancer, bone destruction, neurological disorders, and so on. This review focuses on current work carried out in producing different types of hybrid drug carriers identifying their properties, fabrication techniques, and areas where they have been applied. A brief introduction on understating the requirement for blending organic-inorganic components into a nanohybrid drug carrier is followed with an elaboration given about the different types of OINHs developed currently highlighting their properties and applications. Then, different fabrication techniques are discussed given attention to surface functionalization, one-pot synthesis, wrapping, and electrospinning methods. Finally, it is concluded by briefing the challenges that are remaining to be addressed to obtain multipurpose nanohybrid drug carriers with wider applicability. This article is categorized under: Therapeutic Approaches and Drug Discovery > Emerging Technologies.

Electrospun oral formulations for combined photo-chemotherapy of colon cancer

In this work, we report new formulations for the combined photo-chemotherapy of colon cancer. Fibers were fabricated via coaxial-electrospinning with the intent of targeting delivery of the anti-cancer drug carmofur (CAR) and the photosensitizer rose bengal (RB) selectively to the colon site. The fibers comprised a hydroxypropyl methylcellulose (HPMC) core loaded with the active ingredients, and a pH-sensitive Eudragit L100-55 shell. The fibers were found to be homogeneous and cylindrical and have visible core-shell structures. X-ray diffraction and differential scanning calorimetry demonstrated that both CAR and RB were present in the fibers in the amorphous physical form. In vitro drug release studies showed that the fibers have the potential to selectively deliver drugs to the colon, with only 10-15 % release noted in the acidic conditions of the stomach but sustained release at pH 7.4. Cytotoxicity studies were undertaken on human dermal fibroblast (HDF) and colon cancer (Caco-2) cells, and the influence of light on cell death was also explored. The fibers loaded with CAR alone showed obvious toxicity to both cell lines, with and without the application of light. The RB-loaded fibers led to high viability (ca. 80% for both cell types) in the absence of light, but much greater toxicity was noted (30-50%) with light. The same trends were observed with the formulation containing both CAR and RB, but with lower viabilities. The RB and RB/CAR loaded systems show clear selectivity for cancerous over non-cancerous cells. Finally, mucoadhesion studies revealed there were strong adhesive forces between the rat colonic mucosa and the fibers after they had passed through an acidic environment. Such electrospun fibers thus could have potential in the development of oral therapies for colon cancer.

Electrospun fibers and their application in drug controlled release, biological dressings, tissue repair, and enzyme immobilization

Electrospinning is a method of preparing microfibers or nanofibers by using an electrostatic force to stretch the electrospinning fluid. Electrospinning has gained considerable attention in many fields due to its ability to produce continuous fibers from a variety of polymers and composites in a simple way. Electrospun nanofibers have many merits such as diverse chemical composition, easily adjustable structure, adjustable diameter, high surface area, high porosity, and good pore connectivity, which give them broad application prospects in the biomedical field. This review systematically introduced the factors influencing electrospinning, the types of electrospun fibers, the types of electrospinning, and the detailed applications of electrospun fibers in controlled drug release, biological dressings, tissue repair and enzyme immobilization fields. The latest progress of using electrospun fibers in these fields was summarized, and the main challenges to be solved in electrospinning technology were put forward.

The effect of collection substrate on electrospun ciprofloxacin-loaded poly(vinylpyrrolidone) and ethyl cellulose nanofibers as potential wound dressing materials

In this work, nanofibers based on hydrophilic poly(vinylpyrrolidone) (PVP) and hydrophobic ethyl cellulose (EC) were generated via electrospinning. A model antibiotic, ciprofloxacin (CIF), was also incorporated into the fibers. Fibers were collected on both a foil substrate and a commercial gauze, the latter in the interests of developing a smart fabric. Electron microscopy images revealed that the fibers collected on both foil and fabric were homogeneous and cylindrical. Infrared spectroscopy, X-ray diffraction and differential scanning calorimetry demonstrated that CIF was successfully loaded into the fibers and present in the amorphous physical form. In vitro drug release tests were conducted to simulate drug release from the formulations into a wound site, and as expected the hydrophilic fibers showed much faster release than their hydrophobic analogues. CIF was released through a combined mechanism of polymer erosion and drug diffusion, and the EC nanofibers displayed close to zero-order release over three days. Fibroblast cells are able to grow and proliferate on the fibers. Finally, inhibition zone assays revealed that the growth of both Gram positive and Gram negative bacteria could be effectively inhibited as a result of the presence of CIF in the fibers. There were no marked differences between the fibers collected on foil and on gauze, and electrospinning can be performed directly onto a gauze substrate to prepare a smart fabric.