Electrospinning of thermoplastic carboxymethyl cellulose/poly(ethylene oxide) nanofibers for use in drug-release systems

Electrospun multi-chamber core-shell nanofibers and their controlled release behaviors: A review

Core-shell structure is a concentric circle structure found in nature. The rapid development of electrospinning technology provides more approaches for the production of core-shell nanofibers. The nanoscale effects and expansive specific surface area of core-shell nanofibers can facilitate the dissolution of drugs. By employing ingenious structural designs and judicious polymer selection, specialized nanofiber drug delivery systems can be prepared to achieve controlled drug release. The synergistic combination of core-shell structure and materials exhibits a strong strategy for enhancing the drug utilization efficiency and customizing the release profile of drugs. Consequently, multi-chamber core-shell nanofibers hold great promise for highly efficient disease treatment. However, little attention concentration is focused on the effect of multi-chamber core-shell nanofibers on controlled release of drugs. In this review, we introduced different fabrication techniques for multi-chamber core-shell nanostructures, including advanced electrospinning technologies and surface functionalization. Subsequently, we reviewed the different controlled drug release behaviors of multi-chamber core-shell nanofibers and their potential needs for disease treatment. The comprehensive elucidation of controlled release behaviors based on electrospun multi-chamber core-shell nanostructures could inspire the exploration of novel controlled delivery systems. Furthermore, once these fibers with customizable drug release profiles move toward industrial mass production, they will potentially promote the development of pharmacy and the treatment of various diseases. This article is categorized under: Therapeutic Approaches and Drug Discovery > Emerging Technologies.

Comparative study of drug release from electrospun nanofibers loaded with clotrimazole via two different approaches using a fully automated sequential injection system

The development of new drug delivery platforms including the use of nanotechnology has been found of great interest in recent years. Two different loading approaches of the model antimycotic drug clotrimazole into the nanofibrous polycaprolactone and polydioxanone structures including electrospinning of a drug-polymer blend and impregnation of nanofibers with drug have been tested. The final amount of clotrimazole in the nanofibrous materials was determined by HPLC analysis and Raman spectroscopy. The electrospinning of blend approach allowed the adsorption of clotrimazole in a quantity of up to 30 % using mixtures with polymer/clotrimazole ratios from 2:1 to 8:1 (w/w). Ethanolic clotrimazole solutions with concentrations from 2.5 to 3.5 mg L-1 were used for adsorbing clotrimazole in blank nanofibers for 1-3 h with final clotrimazole content ranging from 3.0 to 5.7 %. Furthermore, a comparative liberation study including comparison with commercially available creams was carried out in low pressure flow system. The results obtained confirmed well controlled release of clotrimazole from both types of nanofibers. Compared to commercial pharmaceutical formulations containing 1 % clotrimazole where first-order release kinetics was observed, nanofibrous materials provided linear controlled release (zero-order kinetics) in the tested 3 h period.

Emerging Polymer-Based Nanosystem Strategies in the Delivery of Antifungal Drugs

Nanosystems-based antifungal agents have emerged as an effective strategy to address issues related to drug resistance, drug release, and toxicity. Among the diverse materials employed for antifungal drug delivery, polymers, including polysaccharides, proteins, and polyesters, have gained significant attention due to their versatility. Considering the complex nature of fungal infections and their varying sites, it is crucial for researchers to carefully select appropriate polymers based on specific scenarios when designing antifungal agent delivery nanosystems. This review provides an overview of the various types of nanoparticles used in antifungal drug delivery systems, with a particular emphasis on the types of polymers used. The review focuses on the application of drug delivery systems and the release behavior of these systems. Furthermore, the review summarizes the critical physical properties and relevant information utilized in antifungal polymer nanomedicine delivery systems and briefly discusses the application prospects of these systems.

Water-Resistant Photo-Crosslinked PEO/PEGDA Electrospun Nanofibers for Application in Catalysis

Catalysts are used for producing the vast majority of chemical products. Usually, catalytic membranes are inorganic. However, when dealing with reactions conducted at low temperatures, such as in the production of fine chemicals, polymeric catalytic membranes are preferred due to a more competitive cost and easier tunability compared to inorganic ones. In the present work, nanofibrous mats made of poly(ethylene oxide), PEO, and poly(ethylene glycol) diacrylate, PEGDA, blends with the Au/Pd catalyst are proposed as catalytic membranes for water phase and low-temperature reactions. While PEO is a water-soluble polymer, its blending with PEGDA can be exploited to make the overall PEO/PEGDA blend nanofibers water-resistant upon photo-crosslinking. Thus, after the optimization of the blend solution (PEO molecular weight, PEO/PEGDA ratio, photoinitiator amount), electrospinning process, and UV irradiation time, the resulting nanofibrous mat is able to maintain the nanostructure in water. The addition of the Au₆/Pd₁ catalyst (supported on TiO₂) in the PEO/PEGDA blend allows the production of a catalytic nanofibrous membrane. The reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP), taken as a water phase model reaction, demonstrates the potential usage of PEO-based membranes in catalysis.

Electrospun hybrid nanofibers: Fabrication, characterization, and biomedical applications

Nanotechnology is one of the most promising technologies available today, holding tremendous potential for biomedical and healthcare applications. In this field, there is an increasing interest in the use of polymeric micro/nanofibers for the construction of biomedical structures. Due to its potential applications in various fields like pharmaceutics and biomedicine, the electrospinning process has gained considerable attention for producing nano-sized fibers. Electrospun nanofiber membranes have been used in drug delivery, controlled drug release, regenerative medicine, tissue engineering, biosensing, stent coating, implants, cosmetics, facial masks, and theranostics. Various natural and synthetic polymers have been successfully electrospun into ultrafine fibers. Although biopolymers demonstrate exciting properties such as good biocompatibility, non-toxicity, and biodegradability, they possess poor mechanical properties. Hybrid nanofibers from bio and synthetic nanofibers combine the characteristics of biopolymers with those of synthetic polymers, such as high mechanical strength and stability. In addition, a variety of functional agents, such as nanoparticles and biomolecules, can be incorporated into nanofibers to create multifunctional hybrid nanofibers. Due to the remarkable properties of hybrid nanofibers, the latest research on the unique properties of hybrid nanofibers is highlighted in this study. Moreover, various established hybrid nanofiber fabrication techniques, especially the electrospinning-based methods, as well as emerging strategies for the characterization of hybrid nanofibers, are summarized. Finally, the development and application of electrospun hybrid nanofibers in biomedical applications are discussed.

Multifunctional Scaffolds Based on Emulsion and Coaxial Electrospinning Incorporation of Hydroxyapatite for Bone Tissue Regeneration

Tissue engineering is nowadays a powerful tool to restore damaged tissues and recover their normal functionality. Advantages over other current methods are well established, although a continuous evolution is still necessary to improve the final performance and the range of applications. Trends are nowadays focused on the development of multifunctional scaffolds with hierarchical structures and the capability to render a sustained delivery of bioactive molecules under an appropriate stimulus. Nanocomposites incorporating hydroxyapatite nanoparticles (HAp NPs) have a predominant role in bone tissue regeneration due to their high capacity to enhance osteoinduction, osteoconduction, and osteointegration, as well as their encapsulation efficiency and protection capability of bioactive agents. Selection of appropriated polymeric matrices is fundamental and consequently great efforts have been invested to increase the range of properties of available materials through copolymerization, blending, or combining structures constituted by different materials. Scaffolds can be obtained from different processes that differ in characteristics, such as texture or porosity. Probably, electrospinning has the greater relevance, since the obtained nanofiber membranes have a great similarity with the extracellular matrix and, in addition, they can easily incorporate functional and bioactive compounds. Coaxial and emulsion electrospinning processes appear ideal to generate complex systems able to incorporate highly different agents. The present review is mainly focused on the recent works performed with Hap-loaded scaffolds having at least one structural layer composed of core/shell nanofibers.

New Application Field of Polyethylene Oxide: PEO Nanofibers as Epoxy Toughener for Effective CFRP Delamination Resistance Improvement

Delamination is the most severe weakness affecting all composite materials with a laminar structure. Nanofibrous mat interleaving is a smart way to increase the interlaminar fracture toughness: the use of thermoplastic polymers, such as poly(ε-caprolactone) and polyamides (Nylons), as nonwovens is common and well established. Here, electrospun polyethylene oxide (PEO) nanofibers are proposed as reinforcing layers for hindering delamination in epoxy-based carbon fiber-reinforced polymer (CFRP) laminates. While PEO nanofibers are well known and successfully applied in medicine and healthcare, to date, their use as composite tougheners is undiscovered, resulting in the first investigation in this application field. The PEO-modified CFRP laminate shows a significant improvement in the interlaminar fracture toughness under Mode I loading: +60% and +221% in G I,C and G I,R, respectively. The high matrix toughening is confirmed by the crack path analysis, showing multiple crack planes, and by the delamination surfaces, revealing that extensive phase separation phenomena occur. Under Mode II loading, the G II enhancement is almost 20%. Despite a widespread phase separation occurring upon composite curing, washings in water do not affect the surface delamination morphology, suggesting a sufficient humidity resistance of the PEO-modified laminate. Moreover, it almost maintains both the original stiffness and glass transition temperature (T g), as assessed via three-point bending and dynamic mechanical analysis tests. The achieved results pave the way for using PEO nanofibrous membranes as a new effective solution for hindering delamination in epoxy-based composite laminates.

Preparation nanocapsules chitosan modified with selenium extracted from the Lactobacillus acidophilus and their anticancer properties

This study synthesized new modified imaging nanocapsules (NCs) of gallium@deferoxamine/folic acid/chitosan/polyaniline/polyvinyl alcohol (Ga@DFA/FA/CS/PANI/PVA) containing Morus nigra extract by selenium nanoparticles prepared from Lactobacillus acidophilus. Se nanoparticles were then deposited on (Ga@DFA/FA/CS/PANI/PVA) using the impregnation method. The modified contrast agents were further mixed with M. nigra extract, and their antibacterial activities were investigated by applying them on L929 cell lines. The influence of variable factors including surfactant, solvent, aqueous phase, pH, buffer, minimum Inhibitory concentration (MIC), minimum bactericidal concentration (MBC), cytotoxicity on cancer cells., antibiotic, antibiogram, release and loading, stirring effect, the concentration of nanoparticle, olive oil, and thermotical methods was investigated. The structure and morphology of the synthesized contrast agents were characterized by zeta potential sizer analysis (ZPS), X-Ray diffraction (XRD), Fourier-transform infrared (FT-IR), energy dispersive X-ray (EDX), ultraviolet-visible (UV-Vis) spectra, and scanning electron microscope (SEM). The experimental section was conducted and monitored by response surface methods (RSM) and MTT, MIC, MBC, and cancer cytotoxic conversion assay. Antibiogram testing of NCs on Pseudomonas aeruginosa bacteria was successful, and MIC = 2 factor was obtained with less harmful effect.

An overview on electrospinning and its advancement toward hard and soft tissue engineering applications

One of the emerging technologies of the recent times harboring nanotechnology to fabricate nanofibers for various biomedical and environmental applications are electrospinning (nanofiber technology). Their relative ease in use, simplicity, functionality and diversity has surpassed the pitfalls encountered with the conventional method of generating fibers. This review aims to provide an overview of electrospinning, principle, methods, feed materials, and applications toward tissue engineering. To begin with, evolution of electrospinning and its typical apparatus have been briefed. Simultaneously, discussion on the production of nanofibers with diversified feed materials such as polymers, small molecules, colloids, and nanoparticles and its transformation into a powerful technology has been dealt with. Further, highlights on the application of nanofibers in tissue engineering and the commercialized products developed using nanofiber technology have been summed up. With this rapidly emerging technology, there would be a great demand pertaining to scalability and environmental challenge toward tissue engineering applications.

Polyethylenimine-Functionalized Nanofiber Nonwovens Electrospun from Cotton Cellulose for Wound Dressing with High Drug Loading and Sustained Release Properties

Electrospun cellulose nanofiber nonwovens have shown promise in wound dressing owing to the highly interconnected pore structure, high hydrophilicity coupled with other coveted characteristics of biodegradability, biocompatibility and renewability. However, electrospun cellulose wound dressings with loaded drugs for better wound healing have been rarely reported. In this study, a novel wound dressing with a high drug loading capacity and sustained drug release properties was successfully fabricated via electropinning of cellulose followed by polyethylenimine (PEI)-functionalization. Remarkably, the grafted PEI chains on the surface of electrospun cellulose nanofibers provided numerous active amino groups, while the highly porous structure of nonwovens could be well retained after modification, which resulted in enhanced adsorption performance against the anionic drug of sodium salicylate (NaSA). More specifically, when immersed in 100 mg/L NaSA solution for 24 h, the as-prepared cellulose-PEI nonwoven displayed a multilayer adsorption behavior. And at the optimal pH of 3, a high drug loading capacity of 78 mg/g could be achieved, which was 20 times higher than that of pristine electrospun cellulose nonwoven. Furthermore, it was discovered that the NaSA-loaded cellulose-PEI could continuously release the drug for 12 h in simulated body fluid (SBF), indicating the versatility of cellulose-PEI as an advanced wound dressing with drug carrier functionalities.

Recent trends in therapeutic application of engineered blood purification materials for kidney disease

Blood purification is a commonly used method to remove excess metabolic waste in the blood in renal replacement therapy. The sufficient removal of these toxins from blood can reduce complications and improve survival lifetime in dialysis patients. However, the current biological blood purification materials in clinical practice are not ideal, where there is an unmet need for producing novel materials that have better biocompatibility, reduced toxicity, and, in particular, more efficient toxin clearance rates and a lower cost of production. Given this, this review has carefully summarized newly developed engineered different structural biomedical materials for blood purification in terms of types and structure characteristics of blood purification materials, the production process, as well as interfacial chemical adsorption properties or mechanisms. This study may provide a valuable reference for fabricating a user-friendly purification device that is more suitable for clinical blood purification applications in dialysis patients.

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

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

Pleurotus eryngii polysaccharide nanofiber containing pomegranate peel polyphenol/chitosan nanoparticles for control of E. coli O157:H7

Pomegranate peel polyphenols (PPP), which are natural, safe, and green antibacterial agents, were introduced and embedded in chitosan to form stable nanoparticles. The PPP@chitosan nanoparticles (PPP@CNPs) were further electrospun into nanofibers based on Pleurotus eryngii polysaccharide (PEP). The preferable distribution of particle size, polydispersity index, and zeta potential was realized through the addition of PPP at 3 mg/mL, which achieved the highest encapsulation rate of 23.71 ± 0.51%. The tensile strength and elongation at break of nanofibers reached 15.76 MPa and 0.69% with the addition of 1% PEP through electrospinning. The results of scanning electron microscopy (SEM) and atomic force microscopy (AFM) demonstrated that the addition of nanoparticles increased the diameter of PEP nanofibers from 148 nm to 163 nm, and the surface roughness of the fibers also increased. Meanwhile, the addition of nanoparticles improved the thermal stability of PEP nanofibers. PPP@CNPs/PEP nanofibers can inhibit the growth of E. coli O157:H7 on pork and cucumber surfaces during the five-days storage, and the inhibition rates were all above 95%. Besides, the nanofibers did not have any impact on the color and texture of foods.

Recent Advances in Cellulose-Based Structures as the Wound-Healing Biomaterials: A Clinically Oriented Review

Application of wound-healing/dressing biomaterials is amongst the most promising approaches for wound repair through protection from pathogen invasion/contamination, maintaining moisture, absorbing exudates, modulating inflammation, and facilitating the healing process. A wide range of materials are used to fabricate wound-healing/dressing biomaterials. Active wound-healing/dressings are next-generation alternatives for passive biomaterials, which provide a physical barrier and induce different biological activities, such as antibacterial, antioxidant, and proliferative effects. Cellulose-based biomaterials are particularly promising due to their tunable physical, chemical, mechanical, and biological properties, accessibility, low cost, and biocompatibility. A thorough description and analysis of wound-healing/dressing structures fabricated from cellulose-based biomaterials is discussed in this review. We emphasize and highlight the fabrication methods, applied bioactive molecules, and discuss the obtained results from in vitro and in vivo models of cellulose-based wound-healing biomaterials. This review paper revealed that cellulose-based biomaterials have promising potential as the wound-dressing/healing materials and can be integrated with various bioactive agents. Overall, cellulose-based biomaterials are shown to be effective and sophisticated structures for delivery applications, safe and multi-customizable dressings, or grafts for wound-healing applications.

New method of creating hybrid of buprenorphine loaded rifampin/polyethylene glycol/alginate nanoparticles

An indicator for cytochrome P450 enzymes which have the most fundamental role in methadone metabolism in the liver. In this study preparation in vitro, in vivo release and biological activities of Fe₃O₄@ZnO/rifampin/polyethylene glycol/buprenorphine/alginate nanoparticles investigated. Rifampin is activator for the cytochrome P-3 enzymes which can detoxify residual drugs in the liver. This paper examines the changes pH, absorption rate, drug release, in vivo test (30 rats) in selected Wistar rats. All rats were either orally addicted to morphine after 21 days. After establishing dependence based on an observation of behavioral parameters the ability to quit the new drug was evaluated. In vitro and in vitro tests on antibacterial activity and multiple intestinal inflammation in addicts were conducted. Recent drug delivery systems that use polymers cause more sustainability of drug in the body and also prevent drug interactions. This research showed the success of decreasing consumption dose of the drug from 0.004 to 0.0005 mg, increasing lifetime from 24 to 32 h to 72-96 h, and decreasing the number of hepatic tissues that were damaged. The results of this investigation were confirmed by clinical tests and the dyeing process of mason tri‑chromium and hematoxylin and eosin.

Three-Dimensional Coating of SF/PLGA Coaxial Nanofiber Membranes on Surfaces of Calcium Phosphate Cement for Enhanced Bone Regeneration

Calcium phosphate cements (CPCs) have been widely used for the study of bone regeneration because of their excellent physical and chemical properties, but poor biocompatibility and lack of osteoinductivity limit potential clinical applications. To overcome these limitations, and based on our previous research, CPC scaffolds were prepared with CPC as the principal material and polyethylene glycol (PEG) as a porogen to introduce interconnected macropores. Using a bespoke electrospinning auxiliary receiver, silk fibroin (SF)/poly(lactide-co-glycolide) (PLGA) coaxial nanofibers containing dexamethasone (DXM) and recombinant human bone morphogenetic protein-2 (rhBMP2) were fabricated which were coated on the surface of the CPC. By comparing the surface morphology by SEM, hydrophilicity, results of FTIR spectroscopy, and mechanical properties of the composite materials fabricated using different electrospinning times (20, 40, 60 min), the CPC surface constructed by electrospinning for 40 min was found to exhibit the most appropriate physical and chemical properties. Therefore, composite materials were built for further study by electrospinning for 40 min. The osteogenic capacity of the SF/PLGA/CPC, SF-DXM/PLGA/CPC, and SF-DXM/PLGA-rhBMP2/CPC scaffolds was evaluated by in vitro cell culture with rat bone marrow mesenchymal stem cells (BMSCs) and using a rat cranial defect repair model. ALP activity, calcium deposition levels, upregulation of osteogenic genes, and bone regeneration in skull defects in rats with SF-DXM/PLGA-rhBMP2/CPC implants were significantly higher than in rats implanted with the other scaffolds. These results suggest that drug-loaded coaxial nanofiber coatings prepared on a CPC surface can continuously and effectively release bioactive drugs and further stimulate osteogenesis. Therefore, the SF-DXM/PLGA-rhBMP2/CPC scaffolds prepared in this study demonstrated the most significant potential for the treatment of bone defects.

Electrospun Nanocomposites Containing Cellulose and Its Derivatives Modified with Specialized Biomolecules for an Enhanced Wound Healing

Wound healing requires careful, directed, and effective therapies to prevent infections and accelerate tissue regeneration. In light of these demands, active biomolecules with antibacterial properties and/or healing capacities have been functionalized onto nanostructured polymeric dressings and their synergistic effect examined. In this work, various antibiotics, nanoparticles, and natural extract-derived products that were used in association with electrospun nanocomposites containing cellulose, cellulose acetate and different types of nanocellulose (cellulose nanocrystals, cellulose nanofibrils, and bacterial cellulose) have been reviewed. Renewable, natural-origin compounds are gaining more relevance each day as potential alternatives to synthetic materials, since the former undesirable footprints in biomedicine, the environment, and the ecosystems are reaching concerning levels. Therefore, cellulose and its derivatives have been the object of numerous biomedical studies, in which their biocompatibility, biodegradability, and, most importantly, sustainability and abundance, have been determinant. A complete overview of the recently produced cellulose-containing nanofibrous meshes for wound healing applications was provided. Moreover, the current challenges that are faced by cellulose acetate- and nanocellulose-containing wound dressing formulations, processed by electrospinning, were also enumerated.

New and Enzymatic Targeted Magnetic Macromolecular Nanodrug System Which Delivers Methadone and Rifampin Simultaneously

An indicator for cytochrome P450 (CYP-450) enzymes includes CYP-450 which has the most fundamental role in methadone metabolism in the liver. The aim of this study is to design and interface a macromolecular nanodrug system to deliver rifampin (RIF) and methadone (MTD) simultaneously to the liver based on magnetic nanoparticles (MNPs). RIF increases the metabolism of MTD in the liver. In this study, MTD was linked to a magnetic nanocapsule including RIF by a heterocyclic linker. This heterocyclic linker was prepared in five steps. Fourier transform infrared spectroscopy and NMR indicated the synthesis of the heterocyclic linker, scanning electron microscopy and confocal fluorescence microscopy exhibited the morphology of NPs and loading MTD. Atomic force microscopy was applied to indicate the three-dimensional topology of NPs and the conglomeration on them. Magnetization properties of loaded and unloaded NPs were characterized by vibrating-sample magnetometer. These patterns indicated superparamagnetic properties of MNPs therefore these NPs do not retain any magnetism after removal of a magnetic field. In vitro release studies of RIF and MTD by UV-vis measurements in several buffer solutions demonstrated that behavior of drug release is related to pH. The histopathology study was performed on the liver of rats injected with MTD, morphine (MOR), and the prepared drug. Cytotoxicity of the prepared sample on MCF-7 cell line assay was assessed via 3-[4, 5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide solution. The histopathology study indicated that the cotreatment of the synthesized drug attenuated hepatic lesions. Delivery of RIF and MTD simultaneously to the liver by MNPs (1) increases MTD metabolism because of increasing CYP-450 enzymes induced by RIF and (2) decreases hepatic lesions via injection of the synthesized drug with cotreatment by MOR.

Fabrication and Characterization of Carboxymethyl Starch/Poly(l-Lactide) Acid/β-Tricalcium Phosphate Composite Nanofibers via Electrospinning

A natural polymer of carboxymethyl starch (CMS) was used in combination with the inorganic mineral of β-Tricalcium Phosphate (β-TCP) and Poly l-lactide (PLLA) to prepare composite nanofibers with the potential to be used as a biomedical membrane. β-TCP contents varied in the range of 0.25% to 1% in the composition of PLLA and CMS. A mixed composition of these organic and inorganic materials was electro-spun to produce composite nanofibers. Morphological investigation indicated that smooth and uniform nanofibers could be produced via this technique. The average of the nanofiber diameters was slightly increased from 190 to 265 nm with the β-TCP content but some agglomeration of particles began to impede in the fiber at a higher content of β-TCP. It was observed that the fibers were damaged at a higher content of β-TCP nanoparticles. With the presence of higher β-TCP, the wettability of the PLLA was also improved, as indicated by the water contact angle measurement from 127.3° to 118°. The crystallization in the composite decreased, as shown in the changes in glass transition (T_g) and melting temperature (T_m) by differential scanning calorimeter (DSC) and X-ray diffraction analysis. Increases in β-TCP contributed to weaker mechanical strength, from 8.5 to 5.7 MPa, due to imperfect fiber structure.

Crosslinked-polyvinyl alcohol-carboxymethyl cellulose/ZnO nanocomposite fibrous mats containing erythromycin (PVA-CMC/ZnO-EM): Fabrication, characterization and in-vitro release and anti-bacterial properties

Recently, nanocomposite nanofibers have been extensively used for biomedical applications. It is expected that simultaneous incorporation of antibiotic drugs and ZnO nanoparticles into nanofiber resulted in providing the synergistic anti-bacterial effect. The main aim of the present study is to fabricate polyvinyl alcohol (PVA)/carboxymethyl cellulose (CMC)-ZnO nanocomposite fibrous mats containing erythromycin (EM) drug and crosslink them using 2% glutaraldehyde vapor and 3% AlCl₃ alcoholic solution. The fabricated nanofibers characterized via TGA, FTIR, TEM, and SEM, indicating that the addition of ZnO nanoparticles and EM molecules into the fabricated nanofibers resulted in changing their average diameter. Their anti-bacterial activity was studied against S. aureus and E. coli and found that PVA-CMC/ZnO-EM nanofibers show excellent antimicrobial activity. In-vitro release profile showed that EM release from PVA-CMC/ZnO-EM nanofibers was slowly increased. Sustained drug release profile and excellent anti-bacterial activity of PVA-CMC/ZnO-EM nanofiber indicated that it was an ideal biomaterial for wound dressings.

Effect of Thermal Treatment on Crystallinity of Poly(ethylene oxide) Electrospun Fibers

Post-process thermal treatment of electrospun fibers obtained from poly(ethylene oxide) (PEO) water and methanol solutions was examined. PEO fibers from methanol solution showed larger diameters as observed by scanning electron microscopy. Fibers both from water and methanol solutions exhibited a significant dimensional stability and surface cracking during the specific exposure time after thermal treatments at 40, 50, and 60 °C. Changes in crystallinity after the thermal treatment were studied by wide-angle X-ray diffraction. The kinetics of secondary crystallization were positively influenced by the as-processed level of the amorphous phase and temperature of thermal treatment. Samples treated at 60 °C were degraded by thermooxidation within the time.

Producing hybrid nanofiber-based on /PAN/Fe3 O4 /zeolite/nettle plant extract/urease and a deformed coaxial natural polymer to reduce toxicity materials in the blood of dialysis patients

On incidence of kidney failure, the concentration of urea increases and there is need for patients to visit the hospital all through the week for blood purification. However, current hemodialysis has been found to reduce only 66-75% urea in the blood of patients. The main goal of this article is to observe the effect of biocompatible and high mechanical hemodiafiltration in reducing urea and creatinine within the shortest time frame, using two methods of Nano electrospinning fiber (hybrid and coaxial). Hybrid electrospinning was made by zeolite 940-HOA(beta), Fe₃ O₄ , polyacrylonitrile as well as the addition of nettle plant's leaf extract. Dispersing solution and enzymes were added to two different syringes and was used in making hybrid nanofibers by the electrospinning process. Nessler's Reagent adsorption method was used for measuring the concentration of ammonia after urease enzyme activation. Second coaxial filter was made by the core-shell electrospinning system and cellulose acetate phthalate (CAP) as well as polyurethane (PU) were utilized. The data show hybrid hemodiafiltration with enzyme coating, decomposed urea and enzymes were activated for two days after electrospinning. The core-shell filtration can also reduce creatinine. Core-shell CAP-PU nanofiber was previously used for intravaginal drug delivery and PU was used as an artificial renal microfluidic chip. Thus, our study focused on using CAP-PU to reduce creatinine in dialysis patients. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 107A: 1736-1743, 2019.

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

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

Separation Emulsion via Non-Ionic Surfactant: An Optimization

Achieving emulsion stability in the petroleum industry is a major challenge due to several problems encountered in the oil refining process, such as corrosion in equipment, high-pressure drops in pipelines, and catalyst poisoning in upstream facilities. Thus, several methods are applied for emulsion treatment and chemical treatment using surface-active agents, a fundamental method in the petroleum industry. The present work investigated the performance of a non-ionic surfactant in separating water in a crude oil emulsion via the bottle test technique. Then, a Fractional Factorial Design (2K−1) was used to characterise the effect of significant variables. In particular, a Pareto chart was employed and factors such as demulsifier dosage, toluene concentration, pressure, sitting time, and temperature were investigated. Accordingly, the parameters applied were further analysed using a Central Composite Design (CCD) based on the Response Surface Method (RSM). The experimental results based on analysis of Variance (ANOVA) show that demulsifier dosage, temperature, and sedimentation times were the main variables affecting the dehydration process, with the highest F-values being 564.74, 94.53 and 78.65 respectively. The increase in the surfactant dosage before critical concentration, temperature and sitting time leads to boosting dehydration efficiency. In addition, a mathematical model was established for the variables, with a coefficient of determination value of 0.9688. Finally, numerical optimisation was performed on the variables and the results show that the optimal values are 1000 ppm, 15.5 mL, −400 mmHg, 120 min, and 90 °C, for demulsifier dosage, toluene concentration, pressure, sitting time, and temperature, respectively.

Recent Progress in Coaxial Electrospinning: New Parameters, Various Structures, and Wide Applications

Electrospinning, a common method for synthesizing 1D nanostructures, has contributed to developments in the electrical, electrochemical, biomedical, and environmental fields. Recently, a coaxial electrospinning process has been used to fabricate new nanostructures with advanced performance, but intricate and delicate process conditions hinder reproducibility and mass production. Herein, recent progress in new emerging parameters for successful coaxial electrospinning, and the various nanostructures and critical application areas resulting from these activities. Relationships between the new parameters and final product characteristics are described, new possibilities for nanostructures achievable via coaxial electrospinning are identified, and new research directions with a view to future applications are suggested.

Nanocellulose-Based Antibacterial Materials

In recent years, nanocellulose-based antimicrobial materials have attracted a great deal of attention due to their unique and potentially useful features. In this review, several representative types of nanocellulose and modification methods for antimicrobial applications are mainly focused on. Recent literature related with the preparation and applications of nanocellulose-based antimicrobial materials is reviewed. The fabrication of nanocellulose-based antimicrobial materials for wound dressings, drug carriers, and packaging materials is the focus of the research. The most important additives employed in the preparation of nanocellulose-based antimicrobial materials are presented, such as antibiotics, metal, and metal oxide nanoparticles, as well as chitosan. These nanocellulose-based antimicrobial materials can benefit many applications including wound dressings, drug carriers, and packaging materials. Finally, the challenges of industrial production and potentials for development of nanocellulose-based antimicrobial materials are discussed.

Nano-hydroxyapatite polymeric hydrogels for dye removal

Herein, two kinds of nano-hydroxyapatite were synthesized from Clam and Magellan shell by wet chemical precipitation method. Mainly, carboxymethyl cellulose/acrylamide/nano-hydroxyapatite composite hydrogels were developed via a free-radical polymerization process and investigated as a sorbent for Acid Blue 113 (AB) from aqueous AB solution. The swelled and kinetic behaviours of hydrogels were investigated using a gravimetric method. The swelling properties of the CMC-AM-hydrogels were influenced by the calcium electrolytes (Ca²⁺) content in nano-hydroxyapatites. The diffusion coefficient value increased with the increase of nano-hydroxyapatite content in the CMC-AM/nHA-CS (0.22353–0.27681 cm² s⁻¹) and CMC-AM/nHA-MS (0.22377–0.29737 cm² s⁻¹) hydrogels. The mechanism of water diffusion was found to be anomalous transport. The CMC-AM/nHA-MS hydrogels showed high AB absorption efficiency and adsorption capacities. These results explained that the nano-hydroxyapatites of Magellan shells based hydrogels are attractive nanocomposite hydrogels for the adsorption of dye in the water purification applications.

Schematic diagram of nHA and nHA based hydrogels development via wet chemical and free-radical polymerization process and absorbent process of nHA hydrogel.

Effect of Nanofibrillated Cellulose Content on the Temperature and Near Infrared Responses of Polyvinyl Butyral Nanofibers-Containing Bilayer Hydrogel System

A novel kind of nanofibrillated cellulose (NFC) reinforced polyvinyl butyral (PVB) nanofibers-containing bilayer hydrogel system was successfully fabricated via the combination of a one-step, in-situ, free radical polymerization and electrospinning. The hydrogel owned high mechanical strength, thermoresponsive, and near infrared bending/unbending properties. The cross-linking density of hydrogels enhanced along with the increase of NFC content. The addition of NFC and PVB nanofibers presented tiny influence on the variation of chemical bond and volume phase transition temperature. The combination between NFC and PVB nanofibers enhanced the mechanical strength and decreased the strain value, which built the base for high bonding strength of two layers and efficient thermoresponsive and near infrared responses. With the increase of NFC content, the bending degree became smaller. The bilayer hydrogel dimensions affected the deformation degree. Bilayer hydrogels with different NFC content own different deformation abilities, which can be designed as different parts of soft actuators and provide superior performance to satisfy various practical application demands.

Nanoencapsulation of Aloe vera in Synthetic and Naturally Occurring Polymers by Electrohydrodynamic Processing of Interest in Food Technology and Bioactive Packaging

This work originally reports on the use of electrohydrodynamic processing (EHDP) to encapsulate Aloe vera (AV, Aloe barbadensis Miller) using both synthetic polymers, i.e., polyvinylpyrrolidone (PVP) and poly(vinyl alcohol) (PVOH), and naturally occurring polymers, i.e., barley starch (BS), whey protein concentrate (WPC), and maltodextrin. The AV leaf juice was used as the water-based solvent for EHDP, and the resultant biopolymer solution properties were evaluated to determine their effect on the process. Morphological analysis revealed that, at the optimal processing conditions, synthetic polymers mainly produced fiber-like structures, while naturally occurring polymers generated capsules. Average sizes ranged from 100 nm to above 3 μm. As a result of their different and optimal morphology and, hence, higher AV content, PVP, in the form of nanofibers, and WPC, of nanocapsules, were further selected to study the AV stability against ultraviolet (UV) light exposure. Fourier transform infrared (FTIR) spectroscopy confirmed the successful encapsulation of AV in the biopolymer matrices, presenting both encapsulants a high chemical interaction with the bioactive components. Ultraviolet-visible (UV-vis) spectroscopy showed that, while PVP nanofibers offered a poor effect on the AV degradation during UV light exposure (∼10% of stability after 5 h), WPC nanobeads delivered excellent protection (stability of >95% after 6 h). This was ascribed to positive interactions between WPC and the hydrophilic components of AV and the inherent UV-blocking and oxygen barrier properties provided by the protein. Therefore, electrospraying of food hydrocolloids interestingly appears as a novel potential nanotechnology tool toward the formulation of more stable functional foods and nutraceuticals.