Reinforcing decellularized small intestine submucosa with cellulose acetate nanofibrous and silver nanoparticles as a scaffold for wound healing applications.

BACKGROUND: The formation of chronic wounds accounts for considerable costs in health care systems. Despite the several benefits of decellularized small intestinal submucosa (SIS) as an appropriate scaffold for different tissue regeneration, it has shortcomings such as lack of antibacterial features and inappropriate mechanical properties for skin tissue regeneration. We aimed to examine the efficacy and safety of decellularized SIS scaffold enhanced with cellulose acetate (CA) and silver (Ag) nanoparticles (NPs) for healing full-thickness wounds. METHODS AND RESULTS: The scaffolds were prepared by decellularizing bovine SIS and electrospinning CA/Ag nanoparticles and characterized using a transmission electron microscope (TEM), scanning electron microscope (SEM), tensile testing, and X-ray diffraction. In vivo evaluations were performed using full-thickness excisions covered with sterile gauze as the control group, SIS, SIS/CA, and SIS/CA/Ag scaffolds on the dorsum of twenty male Wistar rats divided into four groups randomly with 21-days follow-up. All in vivo specimens underwent Masson's trichrome (MT) staining for evaluation of collagen deposition, transforming growth factor-ß (TGF-ß) immunohistochemistry (IHC), and Haematoxylin Eosin (H&E) staining. The IHC and MT data were analyzed with the ImageJ tool by measuring the stained area. The TEM results revealed that Ag nanoparticles are successfully incorporated into CA nanofibers. Assessment of scaffolds hydrophilicity demonstrated that the contact angle of SIS/CA/Ag scaffold was the lowest. The in vivo results indicated that the SIS/CA/Ag scaffold had the most significant wound closure. H&E staining of the in vivo specimens showed the formation of epidermal layers in the SIS/CA/Ag group on day 21. The percentage of the stained area of MT and TGF-ß IHC staining's was highest in the SIS/CA/Ag group. CONCLUSION: The decellularized SIS/CA/Ag scaffolds provided the most significant wound closure compared to other groups and caused the formation of epidermal layers and skin appendages. Additionally, the collagen deposition and expression of TGF-ß increased significantly in SIS/CA/Ag group.

Wood inspired biobased nanocomposite films composed of xylans, lignosulfonates and cellulose nanofibers for active food packaging.

The growing concerns on environmental pollution and sustainability have raised the interest on the development of functional biobased materials for different applications, including food packaging, as an alternative to the fossil resources-based counterparts, currently available in the market. In this work, functional wood inspired biopolymeric nanocomposite films were prepared by solvent casting of suspensions containing commercial beechwood xylans, cellulose nanofibers (CNF) and lignosulfonates (magnesium or sodium), in a proportion of 2:5:3 wt%, respectively. All films presented good homogeneity, translucency, and thermal stability up to 153 °C. The incorporation of CNF into the xylan/lignosulfonates matrix provided good mechanical properties to the films (Young's modulus between 1.08 and 3.79 GPa and tensile strength between 12.75 and 14.02 MPa). The presence of lignosulfonates imparted the films with antioxidant capacity (DPPH radical scavenging activity from 71.6 to 82.4 %) and UV barrier properties (transmittance ≤19.1 % (200-400 nm)). Moreover, the films obtained are able to successfully delay the browning of packaged fruit stored over 7 days at 4 °C. Overall, the obtained results show the potential of using low-cost and eco-friendly resources for the development of sustainable active food packaging materials.

Enhancing Mechanical and Antimicrobial Properties of Dialdehyde Cellulose-Silver Nanoparticle Composites through Ammoniated Nanocellulose Modification.

Given the widespread prevalence of viruses, there is an escalating demand for antimicrobial composites. Although the composite of dialdehyde cellulose and silver nanoparticles (DAC@Ag1) exhibits excellent antibacterial properties, its weak mechanical characteristics hinder its practical applicability. To address this limitation, cellulose nanofibers (CNFs) were initially ammoniated to yield N-CNF, which was subsequently incorporated into DAC@Ag1 as an enhancer, forming DAC@Ag1/N-CNF. We systematically investigated the optimal amount of N-CNF and characterized the DAC@Ag1/N-CNF using FT-IR, XPS, and XRD analyses to evaluate its additional properties. Notably, the optimal mass ratio of N-CNF to DAC@Ag1 was found to be 5:5, resulting in a substantial enhancement in mechanical properties, with a 139.8% increase in tensile elongation and a 33.1% increase in strength, reaching 10% and 125.24 MPa, respectively, compared to DAC@Ag1 alone. Furthermore, the inhibition zones against Escherichia coli and Staphylococcus aureus were significantly expanded to 7.9 mm and 15.9 mm, respectively, surpassing those of DAC@Ag1 alone by 154.8% and 467.9%, indicating remarkable improvements in antimicrobial efficacy. Mechanism analysis highlighted synergistic effects from chemical covalent bonding and hydrogen bonding in the DAC@Ag1/N-CNF, enhancing the mechanical and antimicrobial properties significantly. The addition of N-CNF markedly augmented the properties of the composite film, thereby facilitating its broader application in the antimicrobial field.

Physicomechanical characterizations and in vitro release studies of electrospun ethyl cellulose fibers, solvent cast carboxymethyl cellulose films, and their composites.

Frequent change of wound dressings introduces wound inflammation and infections. In this study, we electrospun phenytoin (PHT) loaded ethyl cellulose (EC) microfibers and solvent cast tetracycline hydrochloride (TCH) loaded carboxymethyl cellulose (CMC) films with the aim to demonstrate tailorable in vitro drug release behaviors suitable for long-term use of wound dressings. Results from tensile testing showed a significant decrease in average elastic moduli from 8.8 ± 0.6 to 3.3 ± 0.3 MPa after incorporating PHT into EC fibers. PHT-loaded EC fibers displayed a slow and zero-ordered release up to 80 % of the total drug at 48 h, while TCH-loaded CMC films demonstrated a rapid and complete release within 30 min. Furthermore, drug-loaded EC/CMC composites were fabricated into fiber-in-film and fiber-on-film composites. Fiber-in-film composites showed stage release of TCH and PHT at 8 h, while fiber-on-film composites demonstrated simultaneous release of PHT and TCH with a prolonged release of TCH from CMC films. In general, electrospun PHT-loaded EC microfibers, solvent cast TCH-loaded CMC films, and their composites were studied to provide a fundamental scientific understanding on the novelty of the ability to modulate drug release characteristics based on the composite designs.

Bacterial cellulose-based hydrogel with regulated rehydration and enhanced antibacterial activity for wound healing.

Bacterial cellulose (BC) hydrogels are promising medical biomaterials that have been widely used for tissue repair, wound healing and cartilage engineering. However, the high water content of BC hydrogels increases the difficulty of storage and transportation. Moreover, they will lose their original hydrogel structure after dehydration, which severely limits their practical applications. Introducing the bio-based polyelectrolytes is expected to solve this problem. Here, we modified BC and combined it with quaternized chitosan (QCS) via a chemical reaction to obtain a dehydrated dialdehyde bacterial cellulose/quaternized chitosan (DBC/QCS) hydrogel with repeated swelling behavior and good antibacterial properties. The hydrogel can recover the initial state on the macro scale with a swelling ratio over 1000 % and possesses excellent antimicrobial properties against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) with a killing rate of 80.8 % and 81.3 %, respectively. In addition, the hydrogel has excellent biocompatibility, which is conducive to the stretching of L929 cells. After 14 d of in vivo wound modeling in rats, it was found that the hydrogel loaded with pirfenidone (PFD) could promote collagen deposition and accelerate wound healing with scar prevention. This rehydratable hydrogel can be stored and transported under dry conditions, which is promising for practical applications.

Facile crosslinking methods for water-durable oven-dried cellulose nanofibril foams and their application as dye adsorbents.

The potential applications of cellulose nanofibril-based foam materials can be expanded by their enhanced water durability. This study proposes two crosslinking methods to improve the water durability of the oven-dried carboxymethylated cellulose nanofibril (CMCNF) foam. The first method involves the addition of a crosslinker, polyamideamine epichlorohydrin. The second method is the self-crosslinking of CMCNFs via heat treatment at 140 °C for less than an hour, which is a simple way to crosslink CMCNF-based materials. Both crosslinking methods resulted in excellent water durability and wet resilience of the foams, which also exhibited high water absorbency. Furthermore, neither method affected the structural nor mechanical properties of the oven-dried CMCNF foams. In particular, self-crosslinking by heat treatment proved to be as effective as using a crosslinking agent. Compared to the freeze-dried foam, the oven-dried foam exhibited slower methylene blue (MB) dye adsorption but a higher maximum adsorption capacity (238-250 mg/g), attributed to the closed pore structure and a larger specific surface area. In addition, the isotherm and reusability of the foam for MB adsorption were investigated. These crosslinking processes expanded the potential use of oven-dried CMCNF foams as adsorbents for cationic dyes.

Preparation and sustained release of diatomite incorporated and Eudragit L100 coated hydroxypropyl cellulose/chitosan aerogel microspheres.

The drug encapsulation efficiency, release rate and time, sustained release, and stimulus-response of carriers are very important for drug delivery. However, these always cannot obtained for the carrier with a single component. To improve the comprehensive performance of chitosan-based carriers for 5-Fu delivery, diatomite-incorporated hydroxypropyl cellulose/chitosan (DE/HPC/CS) composite aerogel microspheres were fabricated for the release of 5-fluorouracil (5-Fu), and the release performance was regulated with the content of diatomite, pH value, and external coating material. Firstly, the 5-Fu loaded DE/HPC/CS composite aerogel microspheres and Eudragit L100 coated microspheres were prepared with cross-linking followed by freeze-drying, and characterized by SEM, EDS, FTIR, XRD, DSC, TG, and swelling. The obtained aerogel microspheres have a diameter of about 0.5 mm, the weight percentage of F and Si elements on the surface are 0.55 % and 0.78 % respectively. The glass transition temperature increased from 179 °C to 181 °C and 185 °C with the incorporation of DE and coating of Eudragit, and the equilibrium swelling percentage of DE/HPC/CS (1.5:3:2) carriers are 101.52 %, 45.27 %, 67.32 % at pH 1.2, 5.0, 7.4, respectively. Then, the effect of DE content on the drug loading efficiency of DE/HPC/CS@5-Fu was investigated, with the increase of DE content, the highest encapsulation efficiency was 82.6 %. Finally, the release behavior of DE incorporated and Eudragit L100 Coated microspheres were investigated under different pH values, and evaluated with four kinetic models. The results revealed that the release rate of 5-Fu decreased with the increase of DE content, sustained release with extending time and pH-responsive were observed for the Eudragit-coated aerogel microspheres.

Facile fabrication of temperature/pH dual sensitive hydrogels based on cellulose and polysuccinimide through aqueous amino-succinimide reaction.

A temperature/pH dual sensitive hydrogel with a semi-interpenetrating network (semi-IPN) structure was synthesized through an aqueous amino-succinimide reaction between water-soluble polysuccinimide and polyethyleneimine in the presence of thermosensitive cellulose derivatives. Single-factor experiments were carried out to optimize the preparation conditions of the semi-IPN hydrogel. The swelling behavior and cytotoxicity assay of the hydrogel were tested. Finally, taking 5- fluorouracil (5-Fu) as a model drug, the release performance of the 5-Fu-loaded hydrogel was investigated. The results indicated that the swelling ratio (SR) first decreased and then increased when the pH of the solutions ascended from 2 to 10. The SR decreased with the increase in temperature. In addition, the swelling behavior of the hydrogel was reversible and reproducible under different pH values and temperatures. The prepared hydrogels had good cytocompatibility. The release behavior of 5-Fu was most consistent with the Korsmeyer-Peppas model and followed the case II diffusion. The acidic environment was beneficial for the release of 5-Fu. The preparation process of the semi-IPN hydrogel is simple and the reaction can proceed quickly in water. The strategy introduced here has great potential for application in the preparation of drug carriers.

All-polysaccharide, self-healing, pH-sensitive, in situ-forming hydrogel of carboxymethyl chitosan and aldehyde-functionalized hydroxyethyl cellulose.

In situ forming hydrogels are promising for biomedical applications, especially in drug delivery. The precursor solution can be injected at the target site, where it undergoes a sol-gel transition to afford a hydrogel. In this sense, the most significant characteristic of these hydrogels is fast gelation behavior after injection. This study describes an all-polysaccharide, rapidly in situ-forming hydrogel composed of carboxymethyl chitosan (CMCHT) and hydroxyethyl cellulose functionalized with aldehyde groups (HEC-Ald). The HEC-Ald was synthesized through acetal functionalization, followed by acid deprotection. This innovative approach avoids cleavage of pyran rings, as is inherent in the periodate oxidation approach, which is the most common method currently employed for adding aldehyde groups to polysaccharides. The resulting hydrogel exhibited fast stress relaxation, self-healing properties, and pH sensitivity, which allowed it to control the release of an encapsulated model drug in response to the medium pH. Based on the collected data, the HEC-Ald/CMCHT hydrogels show promise as pH-sensitive drug carriers.

Design of biodegradable cellulose filtration material with high efficiency and breathability.

Using respiratory protective equipment is one of the relevant preventive measures for infectious diseases, including COVID-19, and for various occupational respiratory hazards. Because experienced discomfort may result in a decrease in the utilization of respirators, it is important to enhance the material properties to resolve suboptimal usage. We combined several technologies to produce a filtration material that met requirements set by a cross-disciplinary interview study on the usability of protective equipment. Improved breathability, environmental sustainability, and comfort of the material were achieved by electrospinning poly(ethylene oxide) (PEO) nanofibers on a thin foam-formed fabric from regenerated cellulose fibers. The high filtration efficiency of sub-micron-sized diethylhexyl sebacate (DEHS) aerosol particles resulted from the small mean segment length of 0.35 µm of the nanofiber network. For a particle diameter of 0.6 µm, the filtration efficiency of a single PEO layer varied in the range of 80-97 % depending on the coat weight. The corresponding pressure drop had the level of 20-90 Pa for the airflow velocity of 5.3 cm/s. Using a multilayer structure, a very high filtration efficiency of 99.5 % was obtained with only a slightly higher pressure drop. This opens a route toward designing sustainable personal protective media with improved user experience.

Silk fibroin and hydroxypropyl cellulose composite injectable hydrogel-containing extracellular vesicles for myocardial infarction repair.

Extracellular vesicles (EVs) have been recognized as one of the promising specific drugs for myocardial infarction (MI) prognosis. Nevertheless, low intramyocardial retention of EVs remains a major impediment to their clinical application. In this study, we developed a silk fibroin/hydroxypropyl cellulose (SF/HPC) composite hydrogel combined with AC16 cell-derived EVs targeted modification by folic acid for the treatment of acute myocardial infarction repair. EVs were functionalized by distearoylphosphatidyl ethanolamine-polyethylene glycol (DSPE-PEG-FA) via noncovalent interaction for targeting and accelerating myocardial infarction repair.In vitro, cytocompatibility analyses revealed that the as-prepared hydrogels had excellent cell viability by MTT assay and the functionalized EVs had higher cell migration by scratch assay.In vivo, the composite hydrogels can promote myocardial tissue repair effects by delaying the process of myocardial fibrosis and promoting angiogenesis of infarct area in MI rat model.

Mechanical biomimetic silk nano fiber-magnesium ion complex/hydroxyethylcellulose/glycerol hydrogel dressing with angiogenic capacity for accelerating scarless diabetic wound healing.

Quick scarless healing remains a key issue for diabetic wounds. Here, a stretchable elastomeric hydrogel dressing composed of hydroxyethylcellulose (HEC), silk nano fiber-magnesium ion complex (Mg2+-SNF) and glycerol (Gly) was developed to optimize mechanical niche, anti-inflammatory and angiogenic behavior simultaneously. The composite hydrogel dressing exhibited skin-like elasticity (175.1 ± 23.9 %) and modulus (156.7 ± 2.5 KPa) while Mg2+-SNF complex endowed the dressing with angiogenesis, both favoring quick scarless skin regeneration. In vitro cell studies revealed that the hydrogel dressing stimulated fibroblast proliferation, endothelial cell migration and vessel-like tube formation, and also induced anti-inflammatory behavior of macrophages. In vivo results revealed accelerated healing of diabetic wounds. The improved granulation ingrowth and collagen deposition suggested high quality repair. Both thinner epidermal layer and low collagen I/III ratio of the regenerated skin confirmed scarless tissue formation. This bioactive hydrogel dressing has promising potential to address the multifaceted challenges of diabetic wound management.

A novel colormetric and light-up fluorescent sensor from flavonol derivative grafted cellulose for rapid and sensitive detection of Hg2+ and its applications in biological and environmental system.

Mercury ion (Hg2+) is one of harmful heavy metal ions that can accumulate inside the human organism and cause some health problems. In the article, a highly effective fluorescent probe named EC-T-PCBM was prepared by grafting flavonol derivatives onto ethyl cellulose for the specific recognition of Hg2+. EC-T-PCBM exhibited a remarkable fluorescence light-up response toward Hg2+ with excellent sensitivity. EC-T-PCBM possessed several prominent sensing properties for Hg2+, such as low detection limit (43.9 nM), short response time (5 min), and wide detection pH range (6-9). The response mechanism of EC-T-PCBM to Hg2+ has been verified through 1H NMR titration and DFT computation. Additionally, EC-T-PCBM not only can be used for accurately determining trace amount of Hg2+ in actual environmental water samples, but also can serve as a portable and rapid device by loading it on test strips for sensitive and selective visualization of Hg2+. More importantly, the confocal fluorescence imaging of onion cells suggested the favorable cell membrane permeability of EC-T-PCBM and its prominent ability to continuously monitor the enrichment from Hg2+ within fresh plant tissues.

Cellulose acetate nanofiber modified with polydopamine polymerized MOFs for efficient removal of noxious organic dyes.

The need to effectively remove toxic organic dyes from aquatic systems has become an increasingly critical issue in the recent years. In pursuit of this objective, polydopamine (PDA)-binary ZIF-8/UiO-66 (MOFs) was synthesized and incorporated into cellulose acetate (CA), producing ZIF-8/UiO-66/PDA@CA composite nanofibers under meticulously optimized conditions. The potential of fabricated nanofibers to remove cationic methylene blue (MB) dye was investigated. Various analysis tools including FTIR, XRD, SEM, zeta potential, BET, tensile strength testing, and XPS were employed. Results revealed a substantial leap in tensile strength, with ZIF-8/UiO-66/PDA@CA registering an impressive 2.8 MPa, as a marked improvement over the neat CA nanofibers (1.1 MPa). ZIF-8/UiO-66/PDA@CA nanofibers exhibit an outstanding adsorption capacity of 82 mg/g, notably outperforming the 22.4 mg/g capacity of neat CA nanofibers. In binary dye systems, these nanofibers exhibit a striking maximum adsorption capacity of 108 mg/g, establishing their eminence in addressing the complexities of wastewater treatment. Furthermore, the adsorption data fitted to the Langmuir isotherm, and the pseudo-second-order kinetic model. The fabricated nanofiber demonstrates good reproducibility and durability, consistently upholding its performance over five cycles. This suite of remarkable attributes collectively underscores its potential as a robust, durable, and highly promising solution for the effective and efficient removal of pernicious MB dye, in the context of both water quality improvement and environmental preservation.

Diosgenin loaded cellulose nanoonion impedes different stages of protein aggregation induced cell death via alleviating mitochondrial dysfunction and upregulation of autophagy.

Protein aggregation is a multifaceted phenomenon prevalent in the progression of neurodegenerative diseases, yielding aggregates of diverse sizes. Recently, increased attention has been directed towards early protein aggregates due to their pronounced toxicity, largely stemming from inflammation mediated by reactive oxygen species (ROS). This study advocates for a therapeutic approach focusing on inflammation control rather than mere ROS inhibition in the context of neurodegenerative disorders. Here, we introduced Camellia sinensis cellulose nanoonion (CS-CNO) as an innovative, biocompatible nanocarrier for encapsulating the phytosteroid diosgenin (DGN@CS-CNO). The resulting nano-assembly, manifesting as spherical entities with dimensions averaging ~180-220 nm, exhibits a remarkable capacity for the gradual and sustained release of approximately 39-44 % of DGN over a 60-hour time frame. DGN@CS-CNO displays a striking ability to inhibit or disassemble various phases of hen egg white lysozyme (HEWL) protein aggregates, including the early (HEWLEA) and late (HEWLLA) stages. In vitro experiments employing HEK293 cells underscore the potential of DGN@CS-CNO in mitigating cell death provoked by protein aggregation. This effect is achieved by ameliorating ROS-mediated inflammation and countering mitochondrial dysfunction, as evidenced by alterations in TNFα, TLR4, and MT-CO1 protein expression. Western blot analyses reveal that the gradual and sustained release of DGN from DGN@CS-CNO induces autophagy, a pivotal process in dismantling intracellular amyloid deposits. In summary, this study not only illuminates a path forward but also presents a compelling case for the utilization of phytosteroid as a formidable strategy against neuroinflammation incited by protein aggregation.

Active cellulose acetate/purple sweet potato anthocyanins@cyclodextrin metal-organic framework/eugenol colorimetric film for pork preservation.

As a natural pH-sensing colorant, purple sweet potato anthocyanins (PSPAs) have demonstrated great potential in colorimetric film for freshness monitoring. However, the photothermal instability of PSPAs is still a challengeable issue. Herein, γ-cyclodextrin metal-organic framework (CD-MOF) loaded with PSPAs (PSPAs@CD-MOF, i.e., PM) and eugenol (EUG) were incorporated in cellulose acetate (CA) matrix for developing a smart active colorimetric film of CA/PM/EUG, where PM and EUG were hydrogen-bonded with CA. Attentions were focused on the photothermal colorimetric stability, colorimetric response, and antibacterial activity of the films. The presence of PM and EUG endowed the film outstanding UV-blocking performance and enhanced the barrier against water vapor and oxygen. Target film of CA/PM15/EUG10 had good photothermal colorimetric stability due to the protection of CD-MOF on PSPAs and the color changes with pH-stimuli were sensitive and reversible. In addition to antioxidant activity, CA/PM15/EUG10 had antibacterial activity against Escherichia coli and Staphylococcus aureus. The application trial results indicated that the CA/PM15/EUG10 was valid to indicate pork freshness and extended the shelf-life by 100 % at 25 °C, which has demonstrated a good perspective on smart active packaging for freshness monitoring and shelf-life extension.

Highly transparent sustainable biogel electrolyte based on cellulose acetate for application in electrochemical devices.

In this study, an easy and low-cost production method for a cellulose acetate-based gel polymer containing lithium perchlorate and propylene carbonate is described, as well as the investigation of its properties for potential use as an electrolyte in electrochemical devices. Cellulose acetate, a biopolymer derived from natural matrix, is colourless and transparent, as confirmed by the UV-Vis spectroscopy, with 85 % transparency in visible spectrum. The gels were prepared and tested at different concentrations and proportions to optimise their properties. Thermogravimetry, XRD, and FTIR analyses revealed crucial characteristics, including a substantial 90 % mass loss between 150 and 250 °C, a semi-crystalline nature with complete salt dissociation within the polymer matrix, and a decrease in intensity at 1780 cm-1 with increasing Li+ ion concentration, suggesting an improvement in ionic conduction capacity. In terms of electrochemical performance, the gel containing 10 % by mass of cellulose acetate and 1.4 M of LiClO4 emerged as the most promising. It exhibited a conductivity of 2.3 × 10-4 S.cm-1 at 25 °C and 3.0 × 10-4 S.cm-1 at 80 °C. Additionally, it demonstrated an ideal shape of cyclic voltammetry curves and stability after 400 cycles, establishing its suitability as an electrolyte in electrochemical devices.

Fabrication of multifunctional ethyl cellulose/gelatin-based composite nanofilm for the pork preservation and freshness monitoring.

In this study, an active and intelligent nanofilm for monitoring and maintaining the freshness of pork was developed using ethyl cellulose/gelatin matrix through electrospinning, with the addition of natural purple sweet potato anthocyanin. The nanofilm exhibited discernible color variations in response to pH changes, and it demonstrated a higher sensitivity towards volatile ammonia compared with casting film. Notably, the experimental findings regarding the wettability and pH response performance indicated that the water contact angle between 70° and 85° was more favorable for the smart response of pH sensitivity. Furthermore, the film exhibited desirable antioxidant activities, water vapor barrier properties and also good antimicrobial activities with the incorporation of ε-polylysine, suggesting the potential as a food packaging film. Furthermore, the application preservation outcomes revealed that the pork packed with the nanofilm can prolong shelf life to 6 days, more importantly, a distinct color change aligned closely with the points indicating the deterioration of the pork was observed, changing from light pink (indicating freshness) to light brown (indicating secondary freshness) and then to brownish green (indicating spoilage). Hence, the application of this multifunctional film in intelligent packaging holds great potential for both real-time indication and efficient preservation of the freshness of animal-derived food items.

A disposable paper-based electrochemical biosensor decorated by electrospun cellulose acetate nanofibers for highly sensitive bio-detection.

Paper-based electrochemical sensors have the characteristics of flexibility, biocompatibility, environmental protection, low cost, wide availability, and hydropathy, which make them very suitable for the development and application of biological detection. This work proposes electrospun cellulose acetate nanofiber (CA NF)-decorated paper-based screen-printed (PBSP) electrode electrochemical sensors. The CA NFs were directly collected on the PBSP electrode through an electrospinning technique at an optimized voltage of 16 kV for 10 min. The sensor was functionalized with different bio-sensitive materials for detecting different targets, and its sensing capability was evaluated by CV, DPV, and chronoamperometry methods. The test results demonstrated that the CA NFs enhanced the detection sensitivity of the PBSP electrode, and the sensor showed good stability, repeatability, and specificity (p < 0.01, N = 3). The electrochemical sensing of the CA NF-decorated PBSP electrode exhibited a short detection duration of ∼5-7 min and detection ranges of 1 nmol mL-1-100 µmol mL-1, 100 fg mL-1-10 µg mL-1, and 1.5 × 102-106 CFU mL-1 and limits of detection of 0.71 nmol mL-1, 89.1 fg mL-1, and 30 CFU mL-1 for glucose, Ag85B protein, and E. coli O157:H7, respectively. These CA NF-decorated PBSP sensors can be used as a general electrochemical tool to detect, for example, organic substances, proteins, and bacteria, which are expected to achieve point-of-care testing of pathogenic microorganisms and have wide application prospects in biomedicine, clinical diagnosis, environmental monitoring, and food safety.