Electrospun Chitosan Nanofibers Research Articles

A systematic investigation of solution and technological parameters for the fabrication and characterization of poly (vinyl alcohol–chitosan electrospun nanofibers

AbstractNanomaterials, particularly nanofibers are demonstrating exceptional potential for medical applications considered as promising systems for the integration of drug molecules, providing an enhancement of drug effectiveness and safety, while reducing drug side effects. Nanofibers based on two polymeric matrices poly(vinyl alcohol) (PVA) and chitosan (CS) have been demonstrated to be safe and promising materials for the drug integration and targeted drug delivery. This article studied the factors influencing on the fabrication and properties of PVA–CS nanofibers, including the impact of solution components on solution structure, rheological properties, electrospinning technology parameters, as well as the structure and thermomechanical properties of the obtained nanofibers have been investigated in details. The increasing of acetic acid concentration has the effect of pH lowering as well as electrical conductivity while heightening its viscosity. The pH, conductivity, and viscosity values of the solution rises as the CS concentration increases. Based on the Hildebrand‐Scatchard solubility theory, calculated Teas diagrams that account intermolecular interactions allow to predict low‐defect nanofibers based on PVA–CS in binary solvent systems with a greater concentration of hydrogen bonds. The optimal solution content and electrospinning parameters were determined. Infrared spectroscopy confirmed that the two polymer materials have a good interaction and the acetic acid was completely separated from the PVA–CS nanofibers. The XRD spectrum reveals that the crystal lattice parameters of the nanofibers change according to the polymer ratio. The polymers ratio also influence on the thermal and tensile properties. Such biosafe polymer materials may be considered as the promising drug delivery systems with the targeted mode of action.

Zingiber officinale and thymus vulgaris extracts co-loaded polyvinyl alcohol and chitosan electrospun nanofibers for tackling infection and wound healing promotion

Infections are severe complications associated with chronic wounds and tardy healing that should be timely treated to achieve rapid and proper tissue repair. To hinder such difficulties, a nanofibrous mat composed of polyvinyl alcohol and chitosan (PVA/CS) was developed by electrospinning method, containing thyme (Thymus vulgaris) and ginger (Zingiber officinale) extracts. The mat containing 10 wt% of the extracts (at the ratio of 50:50) exposed the nanofibers (NFs) with the nanoscale diameter (average 382 ± 60 nm), smooth surface, and defect-free morphology. Likewise, the relevant analyses of the loaded mat displayed high wettability, porosity, and liquid absorption capacity without any adverse interaction. The obtained mat also provided a high antioxidant activity, and its release profile was continuous and sustained for nearly 72 h. Besides, it inhibited the growth of both Gram-positive S. aureus and Gram-negative E. coli strains. Furthermore, the proposed mat significantly accelerated cutaneous wound healing in bacterial-infected rats by preventing bacteria growth at the wound site. At last, histopathology analysis confirmed the ample regeneration of skin structures, forming collagen fibers and appendages. Overall, the proposed mat containing ginger-thyme extracts provides multiple therapeutic capabilities with promising solutions for inhibiting wound infection and accelerating the healing process.

Recent Advancements in Electrospun Chitin and Chitosan Nanofibers for Bone Tissue Engineering Applications

Treatment of large segmental bone loss caused by fractures, osteomyelitis, and non-union results in expenses of around USD 300,000 per case. Moreover, the worst-case scenario results in amputation in 10% to 14.5% of cases. Biomaterials, cells, and regulatory elements are employed in bone tissue engineering (BTE) to create biosynthetic bone grafts with effective functionalization that can aid in the restoration of such fractured bones, preventing amputation and alleviating expenses. Chitin (CT) and chitosan (CS) are two of the most prevalent natural biopolymers utilized in the fields of biomaterials and BTE. To offer the structural and biochemical cues for augmenting bone formation, CT and CS can be employed alone or in combination with other biomaterials in the form of nanofibers (NFs). When compared with several fabrication methods available to produce scaffolds, electrospinning is regarded as superior since it enables the development of nanostructured scaffolds utilizing biopolymers. Electrospun nanofibers (ENFs) offer unique characteristics, including morphological resemblance to the extracellular matrix, high surface-area-to-volume ratio, permeability, porosity, and stability. This review elaborates on the recent strategies employed utilizing CT and CS ENFs and their biocomposites in BTE. We also summarize their implementation in supporting and delivering an osteogenic response to treat critical bone defects and their perspectives on rejuvenation. The CT- and CS-based ENF composite biomaterials show promise as potential constructions for bone tissue creation.

Chitosan electrospun nanofibers derived from Periplaneta americana residue for promoting infected wound healing

Periplaneta americana has been used medicinally for years to treat a wide variety of skin lesions or ulcers. However, a sizable portion of the drug residues that are retained after extraction are routinely thrown away, thus posing a hazard to the environment and depleting resources. In this study, low molecular weight Periplaneta americana chitosan (LPCS) and high molecular weight Periplaneta americana chitosan (HPCS) were extracted from Periplaneta americana residue (PAR) based on the conventional acid-base method and two deacetylation methods. Moreover, the physicochemical properties and structural differences between the above two chitosan and commercial chitosan (CS) were compared using different methods. Next, two nanofibers comprising different ratios of Periplaneta americana chitosan (LPCS or HPCS), polyvinyl alcohol (PVA), and polyethylene oxide (PEO) were prepared and optimized. The above nanofibers exhibited excellent mechanical properties, antibacterial properties, and biocompatibility while facilitating wound healing in an infected rat whole-layer wound model by promoting wound closure, epithelialization, collagen deposition, and inflammation reduction. In brief, this study produced an effective and affordable wound dressing and offered a suggestion for the comprehensive utilization of Periplaneta americana residue.

Electrospun chitosan nanofiber constructing superhigh-water-flux forward osmosis membrane

Forward osmosis (FO) technology exhibits great potential in seawater desalination and wastewater treatment due to its negligible energy consumption and high antifouling, however, the weak desalination capability, especially low water flux, remains challenging. Herein, a cost-effective and high-desalination-performance chitosan (CS)-based FO membrane is developed via coupling the electrospinning CS nanofibers and interfacial-polymerized polyamide (PA). The electrospun nanofibers construct the porous and hydrophilic CS layer with the large pore-diameter of ~274 nm and low thickness of ~10 μm, enabling the effective transport of water molecules, specifically, a superhigh water flux of 107.53 LMH at a low salt-water ratio of 0.24 g·L−1. In addition, such superior desalination performance of the as-prepared FO membrane is universal for the various salt species and concentrations. Our CS nanofiber-based membrane with the high separation capability of water-salt, desirable antibacterial activity, as well as the low cost, offers a roadmap toward the sustainable membrane materials.

Production of chitosan nanofibers using the HFIP/acetic acid mixture as electrospinning solvent

Chitosan nanofiber mats are of interest for biotechnological purposes owing to its physical and chemical properties, nonetheless, the production of pristine chitosan nanofibrous mats is challenging due to some of these traits restrict its solubility in most common solvents, thus limiting its electrospun processability. This work presents the production of pristine chitosan electrospun nanofibers using the 1,1,1,3,3,3-Hexafluoro-2-propanol/acetic acid binary mixture as solvent. This binary solvent improves pristine chitosan spinnability and facilitates the one-step fabrication of highly stable nanofiber mats insoluble in water and aqueous media without the need for crosslinking and neutralization, which implies no need for further washing steps, no waste production, less energy consumption, reagents saving and a significant impact on reducing total processing time compared with previously reported methodologies. Moreover, the aqueous adsorption capacity of methyl orange is improved by the microarchitecture of chitosan as-spun nanofibers produced in this work compared with chitosan powder and film, confirming an essential role of the microstructure and highlighting its potential as bioadsorbent for dye removal.

Effects of wound dressing based on the combination of silver@curcumin nanoparticles and electrospun chitosan nanofibers on wound healing

ABSTRACT Healing of various skin wounds is a lengthy process and often combined with bacterial infection and scar formation. Biomimetic electrospun nanofibrous wound dressing loaded with materials that possess properties of dual antibacterial and tissue repair would be developed to address this problem. In this study, a composite chitosan electrospun nanofibrous material containing Cur@β-CD/AgNPs nanoparticles composed of silver and curcumin possessed synergic effects on antibacterial activity and wound healing. The developed functionalized silver nanoparticles showed effective activity against both Gram-negative and Gram-positive bacteria. In vivo, Cur@β-CD/AgNPs chitosan dressing displayed enhanced wound closure rates compared to commercial AquacelAg. Moreover, Cur@β-CD/AgNPs chitosan dressing contributed to the most uniform collagen distribution by Masson’s trichrome staining. In brief, Cur@β-CD/AgNPs chitosan nanofibers work as a potential wound dressing with antibacterial and antiscarring properties.

Electrospinning of Chitosan for Antibacterial Applications—Current Trends

Chitosan is a natural biopolymer that can be suitable for a wide range of applications due to its biocompatibility, rigid structure, and biodegradability. Moreover, it has been proven to have an antibacterial effect against several bacteria strains by incorporating the advantages of the electrospinning technique, with which tailored nanofibrous scaffolds can be produced. A literature search is conducted in this review regarding the antibacterial effectiveness of chitosan-based nanofibers in the filtration, biomedicine, and food protection industries. The results are promising in terms of research into sustainable materials. This review focuses on the electrospinning of chitosan for antibacterial applications and shows current trends in this field. In addition, various aspects such as the parameters affecting the antibacterial properties of chitosan are presented, and the application areas of electrospun chitosan nanofibers in the fields of air and water filtration, food storage, wound treatment, and tissue engineering are discussed in more detail.

Chondrocyte cell adhesion on chitosan supports using single-cell atomic force microscopy

In this work, functional scaffolds based on electrospun chitosan nanofibers are unprecedentedly studied in terms of their force cell adhesion response. To prove cell compatibility of this biomaterial, chondrocyte interactions are investigated using atomic force microscopy in which a single cell is fixed to the cantilever and approached to the chitosan mat for a given contact time. Then, the cantilever is retracted and cell interactions are studied. Force jumps distribution for cell detachment is described and the adhesion energy is determined comparing nanofiber mats with homogeneous films and a BSA coated surface as control. Force adhesion on chitosan films, equals 460 ± 150 pN, is found slightly higher than on porous fiber mats (410 ± 135 pN) indicating that more cell-substrate bonds could be formed on a flat contact surface for a contact time of 60 s. The same trend was observed for a contact of 120 s between the cell and the substrate. The adhesion on hydrophilic chitosan surface at t = 60 s, is much larger than on the control surface (210 ± 90 pN) due to its positive character and ability for H-bond stabilization.

Polydopamine treatment of chitosan nanofibers for the conception of osteoinductive scaffolds for bone reconstruction

We report the influence of treatment time of electrospun chitosan nanofibers (CHT NFs) in dopamine hydrochloride bath (2 mg.mL−1 in 10 mM Tris buffer, pH 8.5) on the extent of the polydopamine (pDA) coating on NFs surface. The reaction was characterized by FTIR and SEM analysis and the cytocompatibility of the scaffolds toward MT3C3-E1 cells was assessed. Biomimetic deposition of hydroxyapatite (HA) in 1.5xSBF batch was investigated by SEM-EDS and XRD. Samples treated in dopamine bath during 2 h promoted the structural stability of NFs in PBS, provided optimal cytocompatibility and induced the in vitro biomineralization from 6 days in 1.5xSBF. The XRD and SEM-EDS investigations confirmed formation of spherical-shaped particles composed of apatitic phase. Finally, this study shows that these NFs-pDA scaffolds prepared in the optimal experimental conditions defined here are promising candidates for application as osteoinductive scaffolds for bone regeneration applied to orthopedic and dental applications.

Preparation and characterization of salicylic acid grafted chitosan electrospun fibers

Chitosan (chi) and its modified forms as electrospun nanofibers have potential applications in advanced water treatment and biomedicine. Polyethylene oxide (PEO) is an additive commonly used to facilitate the formation of chitosan electrospun fibers because PEO (Mw ≥ 400 kDa) affords chain entanglement that stabilize the electrospinning jet, leading to enhanced formation of chi-based electrospun fibers. Herein, we report on the preparation of chitosan grafted with salicylic acid and its utility to afford improved electrospun fibers with low molecular weight (LMw) PEO (Mw » 100 kDa). A comparison of the interactions between original and grafted chitosan with PEO reveals that stable supramolecular assemblies are established between grafted chitosan and PEO, which provides support that such supramolecular interactions favor formation of chitosan electrospun fibers. Moreover, a porous chitosan electrospun nanofiber was prepared through physical treatment that reveals notably higher (ca. 4-fold) dye uptake than the pristine (unmodified) chitosan electrospun nanofibers.

Cephradine drug release using electrospun chitosan nanofibers incorporated with halloysite nanoclay

Abstract The chitosan/polyvinyl alcohol/halloysite nanoclay (CS/PVA/HNC) loaded with cephradine drug electrospun nanofibers (NFs) were fabricated and characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), thermogravimetric analysis (TGA) techniques. FTIR analysis confirmed the hydrogen bonding between the polymer chain and the developed siloxane linkages. SEM analysis revealed the formation of uniform NFs having beads free and smooth surface with an average diameter in 50–200 nm range. The thermal stability of the NFs was increased by increasing the HNC concentration. The antimicrobial activity was examined against Escherichia coli and staphylococcus strains and the NFs revealed auspicious antimicrobial potential. The drug release was studied at pH 7.4 (in PBS) at 37 °C. The drug release analysis showed that 90% of the drug was released from NFs in 2 h and 40 min. Hence, the prepared NFs could be used as a potential drug carrier and release in a control manner for biomedical application.

Use of Electrospun Chitosan Nanofibers as Nanocarriers of Artemisia sieberi Extract: Evaluation of Properties and Antimicrobial effects

Use of Electrospun Chitosan Nanofibers as Nanocarriers of Artemisia sieberi Extract: Evaluation of Properties and Antimicrobial effects

Prussian blue and collagen loaded chitosan nanofibers with NIR-controlled NO release and photothermal activities for wound healing

1 Prussian blue and collagen loaded chitosan electrospun nanofibers were fabricated. 2 The chitosan nanofibers possess NIR controlled NO release and PTT activities. 3 The nanofibers displayed synergetic antibacterial against E. coli and S. aureus . 4 The nanofibers promoted collagen deposition, cell growth, and epithelialization. 5 The nanofibers provide sufficient biosafety for wound healing. Nitric oxide (NO) has emerged as a potential wound therapeutic agent due to its pivotal role in the wound healing processes. Nevertheless, NO-based therapy for clinical applications is still restricted due to its gaseous state and short half-life. Here we exploited a wound dressing by incorporating sodium nitroprusside doped prussian blue nanoparticals and Type I collagen into the chitosan/poly(vinyl alcohol) nanofibers through the electrospinning method. This hybrid nanofibrous scaffold possess the excellent abilities of NIR controlled NO release, photothermal therapy, and imitation of extra-cellular matrix-like architecture. These synergistic effects could enhance their anti-bactericidal effects in vitro and furthermore accelerate wound healing in vivo when compared to control groups. Histological analysis demonstrated the scaffold could promote fibroblast growth and accelerate epithelialization. Moreover, no apparent histological toxicology and negligible damage to major organs were observed, which provided sufficient biosafety for in vivo application. These data indicate the fabricated hybrid nanofibrous scaffold could be used as an ideal candidate for accelerating wound healing and treating chronic wounds.

Cellulose reinforced electrospun chitosan nanofibers bio-based composite sorbent for water treatment applications

Electrospun chitosan–polyethylene oxide/TEMPO-oxidized cellulose (CS–PEO/TOC) bio-based composite was fabricated for the first time for water treatment applications. This new concept allows cellulose and chitosan to be combined in a simpler and efficient way, avoiding the use of harmful solvents, compared to previously published related work. The “Sandwich-like” material is composed of a porous oxidized cellulosic fibers central core (TOC handsheet) and a thin layer of electrospun CS–PEO nanofibers on both sides of the core. Average diameters for CS–PEO and TOC were 159.3 ± 33.7 nm and 21.7 ± 5.1 µm, respectively. Fourier Transform Infrared Spectroscopy (FTIR) was carried out on the bio-based composite. Results suggest that no covalent bonds are involved but rather electrostatic interactions occur which allows bonding of the electrospun nanofiber layers on TOC core and no delamination. CS–PEO electrospinning time was varied to study the effect of nanofiber’s coating weight on strength, permeability and adsorption capacity of the bio-based material. Mechanical properties of the composite were improved over the electrospun nanofiber mat. The CS–PEO provides greater elasticity (strain%) and the TOC provides a higher tensile strength to the material. However, tensile index was reduced by 48% with electrospinning time, while burst index was almost constant. The best conditions were achieved for 2 h electrospinning time. Under these conditions, a high permeable material (290.13 L/m2 hbar) was developed. The adsorption capacity for Cu (II) ions reached up to 27% with only 12 mg of chitosan onto the CS–PEO/TOC (12.42 mg/g). The data fit better to the pseudo-second order model, suggesting chemisorption as the main mechanism involved for copper adsorption. This study opens-up potential opportunities for the development of a robust material for wastewater applications at an industrial scale.

Antibacterial Activity and Drug Loading of Moxifloxacin-Loaded Poly(Vinyl Alcohol)/Chitosan Electrospun Nanofibers

In this study, nanofibers with different ratios of poly(vinyl alcohol) and chitosan incorporated with moxifloxacin hydrochloride (MH/PVA/CS) were fabricated through the blending electrospinning, and the morphological features were tested using scanning electron microscopy (SEM). Further characterization of the new nanofiber was accomplished by Thermogravimetric analysis (TG), X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR). Antibacterial activity of the MH-loaded nanofibers at different drug loading were tested and compared with the blank group. Experimental results show that the MH/PVA/CS nanofibers exhibited the good antibacterial properties against Staphylococcus aureus and Pseudomonas aeruginosa due to the MH incorporation. Compared with blank nanofibers, MH/PVA/CS nanofibers have significantly better antibacterial properties, and different proportions of PVA and CS have a certain effect on the antibacterial activity of nanofibers. The conclusions in this paper show that MH/PVA/CS composite nanofibers may have great potential in antibacterial materials.

Electrospun chitosan nanofibers for wound healing application

Abstract Electrospun nanofibers have been considered as relatively ideal material system for the design and construction of surgical wound dressings in the past few decades. Although there are lots of other biopolymers employed for electrospinning, chitosan is one of the most important biopolymers for the fabrication of electrospun nanofibers, due to its nontoxic, antibacterial, biocompatible as well as biodegradable properties. Electrospun chitosan nanofibers with random or aligned fiber structure can further be cross-linked by physical, chemical and ionic crosslinking methods. The as-crosslinked electrospun chitosan nanofibrous membranes possess enhanced wet stability, improved mechanical property and good biocompatibility, which are necessary for wound healing application. The present work reviews the recent studies on the design and development of electrospun chitosan nanofibers and their applications for wound healing, such as antibacterial materials, hemostatic dressings, angiogenesis and immune regulation.

Study of Third-Degree Burn Wounds Debridement and Treatment by Actinidin Enzyme Immobilized on Electrospun Chitosan/PEO Nanofibers in Rats

In this study, the actinidin enzyme that was extracted from kiwi fruit was immobilized on a scaffold based on electrospun chitosan nanofibers, and its ability to treat burn wounds was investigated. Afterward, cytotoxicity of the nanofibrous patch and nanofibers with actinidin enzyme was evaluated by MTT test separately on skin fibroblast cells (AGO1522), and their efficacy was investigated on rat model’s full-thickness burn wounds. As a result, SEM showed the diameters of the fibers that were in a range of 100-200 nm depending on the electrospinning condition. MTT results confirmed the cell viability is exposing the enzyme and nanofibers. Then evaluating wound closure percentage in animal samples was analyzed by statistical tests. Considering P<0/05, a significant difference in the rate of wound closure between the groups was observed. Histopathological assays also showed the accelerating effect of the nanofibrous patch with an enzyme in epithelisation, angiogenesis, collagen deposition, and its effective role in scar formation prevention. In this study, actinidin also showed perfect compatibility with cells, and chitosan could prevent wounds infection. So using this bandage could eliminate the scars and reduce the treatment time.

The role of nanohydroxyapatite on the morphological, physical, and biological properties of chitosan nanofibers

This study aimed to evaluate the effects of nanohydroxyapatite (nHAp) particles on the morphological, chemical, physical, and biological properties of chitosan electrospun nanofibers. nHAp particles with a 1.67 Ca/P ratio were synthesized via the aqueous precipitation method, incorporated into chitosan polymer solution (0.5 wt%), and electrospun into nHAp-loaded fibers (ChHa fibers). Neat chitosan fibers (nHAp-free, Ch fibers) were used as the control. The electrospun fiber mats were characterized using morphological, topographical, chemical, thermal, and a range of biological (antibacterial, antibiofilm, cell viability, and alkaline phosphatase [ALP] activity) analyses. Data were analyzed using ANOVA and Tukey's test (α = 0.05). ChHa fibers demonstrated a bead-like morphology, with thinner (331 ± 110 nm) and smoother (Ra = 2.9 ± 0.3 μm) distribution as compared to the control fibers. Despite showing similar cell viability and ALP activity to Ch fibers, the ChHa fibers demonstrated greater antibacterial potential against most tested bacteria (except for P. intermedia), and higher antibiofilm activity against P. gingivalis biofilm. The incorporation of nHAp particles did not jeopardize the overall morphology, topography, physical, and biological characteristics of the chitosan nanofibers. The combination of nHAp particles with chitosan can be used to engineer bioactive, electrospun composite nanofibers with potential applications in regenerative dentistry.

A Biocompatible Nanofibers‐Based Microchip for Isolation and Nondestructive Release of Fetal Nucleated Red Blood Cells

AbstractThe enrichment and analysis of fetal nucleated red blood cells (fNRBCs) with fetal intact genome provide an entry for noninvasive prenatal diagnostics (NIPD) as well as intervention of birth defects. Although efficiently fishing and counting fNRBCs from maternal peripheral blood is gaining tremendous interest for decades, it has been impeded recently by its low abundance. In this study, a compatible chitosan nanofiber microchip is developed to specifically capture and nondestructively release fNRBCs from maternal blood. The substrate has 3D nanostructures formed by electrospun chitosan nanofibers, which integrates with anti‐CD147 to capture fNRBCs with an efficiency of 90%. Subsequently, dithiothreitol is employed to release the captured cells with the efficiency up to 90% while the cell viability is kept at 91.2%. Using the chip, the fNRBCs are successfully isolated from peripheral blood of ten pregnant women in the first trimester ranging from 7 to 13 weeks. Overall, this nanofibrous bioplatform combined with functionalized interface molecules offers a promising strategy to isolate fNRBCs from early gestation period, and provides new prospects for advanced studies to facilitate NIPD in future.