Electroactive bio-composite actuators based on cellulose acetate nanofibers with specially chopped polyaniline nanoparticles through electrospinning

The specific objective of this study was to stabilize a simple valid method to prepare pure nanorod hydroxyapatite (HA) mixed with berberine chloride (BER) and Moghat water extract (ME) as composites for incorporation into cellulose acetate (CA) nanofibers to be used as novel bone scaffolds and to determine their efficacy in bone regeneration process In Vitro. Preparation of HA/BER and HA/ME composites were performed by mixing powders using the ball-milling machine. The HA, HA/BER, and HA/ME composites at a concentration of 6.25, 12.5, 25, 50, 100, and 200 mg were mixed with CA solution (13%), then the fiber was formed using electrospinning technique. The properties of the obtained CA fibers were investigated (SEM, TEM, EDX, FTIR, TGA, water uptake, porosity, and mechanical tests). The efficacy of HA and HA composites loaded into CA nanofiber on osteoblast and osteoclast differentiation were measured by tacking ALP, osteocalcin, TRAcP, calcium, and total protein concentration. Moreover, their effects on cell differentiation (CD90 and PARP- ɣ) and death markers (GSK3b, MAPK, Wnt-5 and β-catenin) were evaluated by using ELISA and qPCR. The obtained TEM results indicated that the continuous CA and CA/HA composites electrospun fibers have ultrafine fiber diameters of about 200 nm and uniform distribution of discrete n-HA clusters throughout. In addition, hydrocortisone (HCT) was found to increase the formation of adipocytes and osteoclastic markers CD90 and p38-MAPK which indicated the bone lose process take placed. Treatment with CA loaded with HA, HA/BER or HA/ME decreased CD90, Wnt-5, PARP- ɣ, GSK3b and p38-MAPK associated elevation of osteogenic markers: ALP and osteocalcin. Moreover, HCT overexpressed RANKL and down expressed Osterix gene. Treatment with CA/HA/BER or CA/HA/ME downregulated RANKL and upregulated Osterix associated with a reduction in RANKL/OPG ratio, at p < 0.05. In conclusion, novel CA composite nanofibers (CA/HA/BER and CA/HA/ME) reversed the HCT adverse effect on osteoblast cell death through canonical and non-canonical pathways regulated by Wnt/β-catenin and Wnt/Ca(2+) pathways. Furthermore, our data confirmed that the novel scaffolds create a crosstalk between RUNX-2, RANKL, p38-MAPK, and Wnt signals which positively impact bone regeneration process. Treatment with CA/HA/BER is better compared to the treatment with CA/HA/ME. Nevertheless, both are considered as alternative biomaterial scaffolds with a potential for biomedical applications in the field of bone tissue engineering.

Development and characterization of antibacterial marine extract-infused cellulose acetate nanofibers as wound dressings for combatting multidrug-resistant wound infections

Cellulose acetate (CA) nanofibers are prepared using solution blow co-spinning (SBS) with poly(ethylene oxide) (PEO). The pure CA membranes are obtained by washing water-soluble PEO from the fibrous CA-PEO blend. Nanofibrous membranes are characterized using optical and scanning electron microscopy (SEM), differential scanning calorimetry (DSC), infrared spectroscopy (ATR-FTIR), and surface zeta potential measurements. Thermal transitions from DSC and ATR-FTIR spectra analysis were used to confirm the removal of the PEO. Although the characteristic signals of PEO are not observed by FTIR, an additional thermal step transition in CA nanofibers indicates the embedding of a small amount of PEO (up to 6 wt%). SEM analysis shows that CA-PEO blends are constituted by fibers with mean diameters from 671 to 857 nm (depending on the SBS parameters), while after PEO removal, diameters range from 567 to 605 nm. We propose a new method for staining CA-PEO membranes with iodine solution in absolute ethanol that allows the differentiation of CA and PEO components with an optical microscope. The microscopy results suggest that PEO assists in the spinning by enveloping CA nanofibers, allowing uninterrupted processing. The successful deacetylation to cellulose using an aqueous KOH solution is confirmed with zeta potential measurements and ATR-FTIR.

Preparation and characterization of self-assembled polyelectrolyte multilayered films on electrospun nanofibers

In vitro Analysis of XLAsp-P2 Peptide Loaded Cellulose Acetate Nanofiber for Wound Healing

Electrospinning emerged as a promising technique to produce scaffolds for cultivated meat in function of its simplicity, versatility, cost-effectiveness, and scalability. Cellulose acetate (CA) is a biocompatible and low-cost material that support cell adhesion and proliferation. Here we investigated CA nanofibers, associated or not with a bioactive annatto extract (CA@A), a food-dye, as potential scaffolds for cultivated meat and muscle tissue engineering. The obtained CA nanofibers were evaluated concerning its physicochemical, morphological, mechanical and biological traits. UV-vis spectroscopy and contact angle measurements confirmed the annatto extract incorporation into the CA nanofibers and the surface wettability of both scaffolds, respectively. SEM images revealed that the scaffolds are porous, containing fibers with no specific alignment. Compared with the pure CA nanofibers, CA@A nanofibers showed increased fiber diameter (420 ± 212nm vs. 284 ± 130nm). Mechanical properties revealed that the annatto extract induces a reduction of the stiffness of the scaffold. Molecular analyses revealed that while CA scaffold favored C2C12 myoblast differentiation, the annatto-loaded CA scaffold favored a proliferative state of these cells. These results suggest that the combination of cellulose acetate fibers loaded with annatto extract may be an interesting economical alternative for support long-term muscle cells culture with potential application as scaffold for cultivated meat and muscle tissue engineering.

Effect of processing parameters on the electrospinning of cellulose acetate studied by response surface methodology

Summary: A feasible method for the preparation of antimicrobial ultrafine fibers with silver nanoparticles was developed by direct electrospinning of a cellulose acetate (CA) solution with small amounts of silver nitrate followed by photoreduction. Silver nanoparticles in ultrafine CA fibers were stabilized by interactions with carbonyl oxygen atoms in CA. Ultrafine CA fibers with silver nanoparticles showed very strong antimicrobial activity.TEM image of an ultrafine CA fiber electrospun from 10 wt.‐% CA solution with 0.5 wt.‐% AgNO3.magnified imageTEM image of an ultrafine CA fiber electrospun from 10 wt.‐% CA solution with 0.5 wt.‐% AgNO3.

Introduction Electrospun polymer derived carbon nanofibers have received attention in recent years as an anode material for energy storage devices due to their enhanced surface area, single step synthesis and shorter diffusion length.[1] Due to these enhanced surface properties, carbon nanofibers showed promising performance even at high C-rate applications.[2] More often, carbon derived from Polyacrylonitrile and its composites are explored as anode material for energy storage devices due to high carbon yield.[1,3,4] However, some other polymeric carbon precursors like polypyrrole, polyvinyl alcohol, and more recently, SU-8 negative photoresist were also explored as an electrode material for a rechargeable Lithium-ion battery. Use of SU-8 facilitates fabrication of three-dimensional electrodes as it can be patterned using photolithography, but it is an expensive source for carbon. The present study is the first report, where cellulose acetate derived carbon fibers have been used as an anode for lithium-ion battery. Cellulose acetate is an inexpensive polymeric carbon precursor. Moreover, our group has recently developed template-assisted electrospinning technique to produce patterned three-dimensional cellulose acetate nanofibrous structures [5] which can be explored further for higher surface area and enhanced performance. Experimental Cellulose acetate polymer (Mw: 29,000 g/mol; Sigma Aldrich, India) was mixed with a binary solvent (acetone and dimethylamide) and the 16 wt.% solution was electrospun to form the nanofibers. As-prepared electrospun cellulose acetate nanofibers mat was regenerated to cellulose nanofabric by deacetylation in 0.05 M NaOH in ethanol, as direct carbonization of cellulose acetate fibers results in melting. After deacetylation cellulose fiber mat was stabilized at 240 °C prior to carbonization at 900 °C in inert atmosphere. Cellulose acetate derived carbon nanofabric was then directly used as a free-standing electrode without any further modification. Electrochemical performance of mat was investigated using Swagelok cell, where lithium metal was used as counter electrode. Results and discussions: Surface morphology of the electrospun fibers was investigated with scanning electron microscope (Figure 1(a)) and deacetylation of cellulose acetate fibers was confirmed by Raman spectroscopy (Figure 1 (b)). A band near 1095 cm -1 can be clearly observed only for regenerated cellulose fiber in figure 1 (b) which corresponds to C-O ring stretching mode, and confirms the conversion of cellulose acetate nanofibers to cellulose nanofibers. Electrochemical performance of cellulose acetate derived carbon fibers was studied at 37.2 mA/g current density. Figure 1(c) shows the cyclic performance of cellulose acetate derived carbon fibers for 100 cycles of charge/discharge. The reversible capacity of these carbon nanofibers was observed to be similar to polyacrylonitrile derived carbon fibers. [3,4] Specific reversible capacity after 100 cycles was found to be ~290 mAh/g. Initial lower columbic efficiency can be attributed to faradic reactions and SEI formation, which is characteristic of carbon materials. Due to the enhanced surface area of free standing carbon fiber mat and entangled three-dimensional porous structure, initial fade was significant. This may be attributed to irreversible surface adsorption of lithium ion. However, after initial 10 cycles, more than 90% of columbic efficiency was retained. Electrochemical performance at higher current densities and detailed structural analysis will be presented in conference presentation.

Multipurpose packaging system based on intelligent carboxymethyl cellulose film and activated cellulose acetate electrospun nanofibers for seafoods.

Effect of deacetylation on wicking behavior of co-electrospun cellulose acetate/polyvinyl alcohol nanofibers blend

Coumarinyl‐thiazole hybrid Schiff bases are well‐known for their broad biological activities, but their poor solubility and low bioavailability limit their therapeutic application. This study aimed to test their antibacterial and anti‐inflammatory activities, wherein, the 3‐(2‐(5‐bromo‐2‐hydroxybenzylideneamino)thiazol‐4‐yl)‐2 H ‐chromen‐2‐one ( 4e ) emerged as most potent. The compound's low cytotoxicity (92.68% cell viability on NIH3T3 cells at 100 µg/mL) and strong anti‐inflammatory activity (57.36% protein denaturation inhibition) confirmed its potential. Subsequently , 4e was successfully incorporated into a cellulose acetate (CA) nanofiber mat via electrospinning (86.00 ± 1.30% encapsulation efficiency). The antibacterial activity of the composite mat was tested against S. aureus and E. faecalis , showing that the CA/ 4e composite retained its excellent antibacterial properties. The mat exhibited a high drug release capacity (88.29 ± 0.30% at pH 7.4), with an initial rapid release (28.31 ± 1.31%) designed for immediate symptomatic relief. In conclusion, the biocompatible CA/ 4e nanofiber mat presents an effective and promising transdermal drug delivery system for this potent coumarin derivative.

Effects of thermal and chemical treatments on the structural stability of cellulose acetate nanofibers

Cellulose acetate nanofibers with photochromic property: Fabrication and characterization

In addition to a number of applications of nanofibres in technical fields such as medical, filtration and biosensing, nanofibres are recently being widely explored in terms of apparel use. Past work has focused on the functional properties of nanofibres for apparel use. Coloured nanofibres were produced to investigate their aesthetic properties for the potential application to apparel. Webs of cellulose acetate nanofibre were electrospun and dyed with a high energy level CI Disperse Red 167:1 dye and a low energy level CI Disperse Blue 56 dye using the continuous pad–dry–bake method. Results revealed that the high energy level dye produced better colour yield than the lower energy level dye. The dyed cellulose acetate nanofibres produced acceptable colorimetric values, colour yield and colour fastness. Young’s modulus of dyed nanofibres increased by threefold in comparison to the undyed cellulose acetate nanofibres. Scanning electron microscopy images showed good morphology with the smooth surface of the dyed cellulose acetate nanofibres.