A fast and sensitive colorimetric sensor for residual chlorine detection made with oxidized cellulose.

Residual chlorine from widespread disinfection processes forms byproducts in water that are harmful to humans and ecosystems. Portable sensors are essential tools for the on-site monitoring of residual chlorine in environmental samples. Here, an inexpensive colorimetric sensor was developed by grafting via amidation the chromogen orthotolidine (OTO) to the surface of a TEMPO-oxidized cellulose filter paper (O-TOFP). A thorough characterization of the sensor strip demonstrated that it was highly stable and that it could be stored for a long period before usage. O-TOFP had a fast response time of 30 s, was highly selective for residual chlorine ions (ClO-) with an accuracy of at least 95 %, and exhibited an excellent limit of detection of only 0.045 mg/L when combined with smartphone image acquisition. With its many positive features, the easy-to-use and robust O-TOFP sensor described here could become a useful tool for the determination of residual chlorine in different water samples.

Oxidized cellulose microneedle patch combined with vascular embolization and local delivery of timolol maleate for hemangiomas.

Hemangiomas are superficial tumors characterized by dense vascular structures that often affect the patient's aesthetic appearance due to the obvious red appearance on the skin. Current treatments, especially timolol maleate in the form of eye drops and hydrogels, suffer from low transdermal drug delivery rates, resulting in prolonged treatment time. To address this challenge, our study introduced a soluble microneedle patch with dextran as the main material to form microcatheters for sustained delivery of timolol maleate. In addition, we proposed a vascular embolization strategy to disrupt the blood supply in hemangiomas. Oxidized cellulose (C-cellulose) was selected for its excellent hemostatic properties. We incorporated C-cellulose into dextran microneedles to facilitate thrombosis in the vascular-rich areas of hemangiomas. The innovative microneedle patch we developed can penetrate the skin to a depth of 430 µm and dissolve rapidly within 3 minutes, ensuring direct drug delivery to the subcutaneous layer. Notably, the treated skin area regained its original appearance within two hours after treatment. In addition to excellent skin permeability and rapid dissolution, these patches significantly promoted apoptosis and inhibited cell migration in mouse hemangioendothelioma EOMA cells. Our results demonstrate that this approach not only achieves significant tumor inhibition in a mouse hemangioma model, but also represents a more effective, convenient, and non-invasive treatment option. Therefore, dextran/C-cellulose/timolol maleate microneedle patch (MNs/Timolol) has broad clinical application prospects in the treatment of hemangiomas, minimizing the risk of additional damage and improving treatment efficacy.

Hydrophobic, ultraviolet radiation-shielding, and antioxidant functionalities of TEMPO-oxidized cellulose nanofibril film coated with modified lignin nanoparticles.

In this study, lignin nanoparticles (LN) and octadecylamine-modified LN (LN-ODA) were utilized as coating materials to enhance the hydrophobic, antioxidant, and ultraviolet radiation-shielding (UV-shielding) properties of a TEMPO-oxidized nanocellulose film (TOCNF). The water contact angle (WCA) of the TOCNF was approximately 53° and remained stable for 1 min, while the modified LN-ODA-coated TOCNF reached over 130° and maintained approximately 85° for an hour. Pure TOCNF exhibited low antioxidant properties (4.7 %), which were significantly enhanced in TOCNF-LN (81.6 %) and modified LN-ODA (10.3 % to 27.5 %). Modified LN-ODA-coated TOCNF exhibited antioxidant properties two to six times higher than those of pure TOCNF. Modified LN-ODA exhibited thermal degradation max (Tmax) at 421 °C, while pure LN showed the main degradation temperature at approximately Tmax 330 °C. The thermal stability of TOCNF-LN-ODA-coated materials remained consistent with that of pure TOCNF, while the crystallinity index of the sample showed a slight decrease due to the amorphous nature of the lignin structure. The tensile strength of TOCNF was approximately 114.1 MPa and decreased to 80.1, 51.3, and 30.3 MPa for LN-ODA coating at 5, 10, and 15 g/m2, respectively.

Green reduction of ZnO nanoparticles using cationic dialdehyde cellulose (cDAC) for efficient Congo red dye removal.

More sustainable materials have been becoming an important concern of worldwide scientists, and cellulosic materials are one alternative in water decontamination. An efficient strategy to improve removal capacity is functionalizing or incorporating nanomaterials in cellulose-based materials. The new hybrid cDAC/ZnONPs was produced by green synthesis of zinc oxide nanoparticles (ZnONPs), promoting the in situ reduction and immobilization on the cationic dialdehyde cellulose microfibers (cDAC) surface to remove Congo red dye from water. cDAC/ZnONPs was characterized by scanning electron microscopy (SEM-EDS) and infrared spectroscopy (FTIR), which showed efficient nanoparticles reduction. Adsorption efficiency on cationic cellulose surface was investigated by pH, contact time, initial concentration, and dye selectivity tests. The material followed the H isotherm model, which resulted in a maximum adsorption capacity of 1091.16 mg/g. Herein, was developed an efficient and ecologically correct new adsorbent, highly effective in Congo red dye adsorption even at high concentrations, suitable for the remediation of contaminated industrial effluents.

A novel strategy and characteristics of PVA/citric acid cross-linked hydrophilic elastic sponge of cellulose based on medicinal herb residue.

A new ultra-hydrophilic elastic sponge composite has been proposed. Medicinal herbs, commonly used in herbal medicine and subsequently discarded, are rich in natural polymer substances, making them promising candidates for various material industries. TEMPO-oxidized cellulose was extracted from medicinal herb residue, and the physicochemical properties of an ultra-hydrophilic elastic sponge, prepared through a PVA and CA impregnate cross-linking process, were investigated. The fabricated composite sponge exhibited an increase in compressive stress-strain proportional to the PVA cross-linking concentration, and its water retention capability was assessed through retention tests. Swelling tests for various solvents were conducted to evaluate the potential use of the sponge in diverse industries, revealing the highest swelling ratio in water. Pressure distribution measurements using prescale film indicated that the sponge's shock absorption capacity was enhanced by PVA cross-linking, leading to improved pressure dispersion.

Paper substrate designed with TEMPO-oxidized cellulose nanofibers/cationic guar gum hydrogel and its application in a colorimetric biosensor for rapid bacteria detection.

The monitoring of foodborne bacterial contamination requires simple and convenient biosensors. This work describes a novel paper-based colorimetric biosensor for the rapid and sensitive bacteria detection. The biosensor was constructed via the encapsulation of D-alanyl-D-alanine capped gold nanoparticles (DADA-AuNPs) in a modified paper that was fabricated by the freeze-drying of TEMPO-oxidized cellulose nanofibers/cationic guar gum composite hydrogel-modified filter paper. The results indicated that the size of DADA-AuNPs largely determined the color of their aqueous system and they exhibited light red to dark red as their size increased from around 6 to 36 nm. All these different sized DADA-AuNPs turned into colorless when encountered with either S. aureus or E. coli. In particular, the smaller the DADA-AuNPs size, the faster the discoloration. The encapsulation of DADA-AuNPs into modified paper negligibly changed their responsiveness towards bacteria. In comparison to the original filter paper and oven-dried hydrogel-modified filter paper, the freeze-dried hydrogel-modified paper was demonstrated to be a better substrate for the encapsulation of DADA-AuNPs since they could be loaded with a larger amount of DADA-AuNPs in a faster way and showed a better perceivable color. This work demonstrated a promising paper-based colorimetric biosensor for the facile and rapid detection of bacteria.

Electric-field-sensitive hydrogel based on pineapple peel oxidized hydroxyethyl cellulose/gelatin/Hericium erinaceus residues chitosan and its study in curcumin delivery.

This study focused on synthesis of innovative hydrogels with electric field response from modified pineapple peel cellulose and hericium erinaceus chitosan and gelatin based on Schiff base reaction. A series of hydrogels were prepared by oxidized hydroxyethyl cellulose, gelatin and chitosan at different deacetylation degree via mild Schiff base reaction. Subsequently experiments towards the characterization of oxidized hydroxyethyl cellulose/gelatin/chitosan (OHGCS) hydrogel polymers were carried out by FTIR/XRD/XPS, swelling performances and electric response properties. The prepared hydrogels exhibited stable and reversible bending behaviors under repeated on-off switching of electric fields, affected by ionic strength, electric voltage and pH changes. The swelling ratio of OHGCS hydrogels was found reduced as deacetylation degree increasing and reached the maximum ratio âˆ¼ 2250 % for OHGCS-1. In vitro drug releasing study showed the both curcumin loading capacity and release amount of Cur-OHGCS hydrogels arrived about 90 % during 6 h. Antioxidation assessments showed that the curcumin-loaded hydrogels had good antioxidation activities, in which, 10 mg Cur-OHGCS-1 hydrogel could reach to the maximum of about 90 % DPPH scavenging ratio. These results indicate the OHGCS hydrogels have potentials in sensor and drug delivery system.

Algal growth inhibition test with TEMPO-oxidized cellulose nanofibers.

Ecotoxicity data on cellulose nanofibers (CNFs) are limited despite their wide potential applications prospects, such as structural and packaging materials, filters, coatings, foods, and cosmetics. In this study, toxicity tests of 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO)-oxidized CNFs (TEMPO-CNFs), which are one of the major CNF products commercially available in Japan, on the green alga Raphidocelis subcapitata were conducted. As nanomaterials are considered difficult-to-test substances, the Organisation for Economic Co-operation and Development has released a guidance document that provides considerations regarding ecotoxicity tests of nanomaterials. In the algal growth inhibition tests of TEMPO-CNFs, there were specific issues to be examined, including the effects of medium components on the characteristics of TEMPO-CNFs, CNF interference with algal density measurements, algal interference with CNF measurements, and the effects of ion concentration changes in the test medium by the addition of CNFs on algal growth. To examine these issues, we conducted preliminary studies and established a suitable test method for algal growth inhibition tests of TEMPO-CNFs. We confirmed that the components in the medium for algal growth inhibition tests had negligible effects on the characteristics (zeta-potential, viscosity, and morphology) and concentration stability of TEMPO-CNFs and that in vitro and in vivo fluorescence measurements were applicable for estimating the algal densities, without interference by TEMPO-CNFs. In contrast, we observed that the grown algae interfered with the CNF concentration measurements. Therefore, we established a method to correct the measured CNF concentrations by estimating the algal contribution. Furthermore, we found that the nutrient salt concentrations in the medium changed due to interactions with CNFs; however, this change did not affect algal growth. Based on the results of the preliminary studies, algal growth inhibition tests of TEMPO-CNFs were conducted using in vitro and in vivo fluorescence measurements, along with measurements of CNFs and ion concentrations in the test dispersions. The test results showed that no growth inhibition was observed on growth rate or yield even at the maximum CNF concentration of 100 mg/L, suggesting that the ecological effect of TEMPO-CNFs on algae was relatively low. The results of this study will be valuable for conducting ecotoxicity assessments on additional CNFs and comparable nanomaterials in future studies.

Platelet Vesicles Synergetic with Biosynthetic Cellulose Aerogels for Ultra-Fast Hemostasis and Wound Healing.

Achieving hemostasis in penetrating and irregular wounds is challenging because the hemostasis factor cannot arrive at the bleeding site, and substantial bleeding will wash away the blood clot. Since the inherently gradual nature of blood clot formation takes time, a physical barrier is needed before blood clot formation. Herein, an ultra-light and shape memory hemostatic aerogel consisting of oxidized bacterial cellulose (OBC) and platelet extracellular vesicles (pVEs) is reported. The OBC-pVEs aerogel provides a physical barrier for the bleeding site by self-expansion, absorbing the liquid from blood to concentrate platelets and clotting factors and accelerating the clot formation by activating platelets and transforming fibrinogen into fibrin. In the rat liver and tail injury models, the blood loss decreases by 73% and 59%, and the bleeding times are reduced by 55% and 62%, respectively. OBC-pVEs aerogel has also been shown to accelerate wound healing. In conclusion, this work introduces an effective tool for treating deep, non-compressible, and irregular wounds and offers valuable strategies for trauma bleeding and wound treatment.

Effect of TEMPO-oxidized bacterial cellulose nanofibers stabilized Pickering emulsion of cinnamon essential oil on structure and properties of gelatin composite films.

Pure gelatin film often exhibits high hydrophilicity and a lack of antibacterial activity, hindering its practical application in the field of food preservation. To address these issues, we incorporated 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO)-oxidized bacterial cellulose (TOBC) nanofibers stabilized cinnamon essential oil (CEO) Pickering emulsions into the gelatin matrix to develop active food packaging films. The study revealed that the good distribution of emulsion droplets in the film matrix. While with increasing Pickering emulsion proportion, the microstructures of composite films were more heterogeneous, showing some pores or cavities. In addition, the insertion of TOBC-stabilized CEO emulsions could improve the elongation at break (EAB), water-resistance, UV blocking ability, and antibacterial activity of film, but reduced its tensile strength (TS) and water vapor barrier properties (WVP). Notably, the film prepared with 4 % TOBC-stabilized CEO Pickering emulsion demonstrated enhanced preservation of strawberries. Overall, the as-prepared gelatin-based active composite films have considerable potential for food packaging.

Photocrosslinkable and hydroplasicable UV-shielding nanocellulose films facilitated by hydroxyl-yne click reaction.

Sustainably-sourced functional nanocellulose materials are vitally important for the green and sustainable development. Herein, we reported photocrosslinkable and hydroplasticable TEMPO-oxidized cellulose nanofiber phenyl propylene ketone ethers (TOCNPPK) films with excellent ultraviolet (UV) shielding, highly reversible processability, and extended mechanical properties, which were facilitated by green hydroxyl-yne click reaction. The introduction of conjugated aromatic ring and vinyl bonds (-C=C-) had been demonstrated the key for the improved overall performance of resultant TOCNPPK, which not only endowed the TOCNPPK with nearly 100 % UV shielding, but also enabled it to be formed into diverse 3D shapes (helix, ring and letters "N, F, U") via the facile hydrosetting method. The photocrosslinkable-enhanced mechanical performance of TOCNPPK films was also attributed to -C=C- which could crosslink via [2π + 2π] cycloaddition reactions under UV-irradiation. The ultimate stress of TOCNPPK films was as high as 210.0 ± 22.8 MPa and the Young's modulus was 11.5 ± 0.7 GPa, much superior to those of 128.6 ± 8.5 MPa and 9.2 ± 0.6 GPa for pristine TOCN films. Furthermore, the TOCNPPK had been demonstrated as efficient nanofillers for both hydrophilic polyvinyl alcohol and lipophilic polycaprolactone to develop advanced biodegradable composite films with the integration of good water-wetting resistance, excellent UV blocking, and photo-enhanced mechanical performance.

Highly Electroactive Tissue Engineering Scaffolds Based on Nanocellulose/Sulfonated Carbon Nanotube Composite Hydrogels for Myocardial Tissue Repair.

Myocardial infarction (MI) has been a serious threat to the health of modern people for a long time. The introduction of tissue engineering (TE) therapy into the treatment of MI is one of the most promising therapeutic schedules. Considering the intrinsic electrophysiological activity of cardiac tissue, we utilized 2,2,6,6-tetramethylpiperidinyl-1-oxyl (TEMPO)-oxidized cellulose nanofibrils (TOCNs) with excellent biocompatibility as the substrate, and sulfonated carbon nanotubes (SCNTs) with remarkable conductivity and water dispersibility as the electrically active material, to prepare TOCN-SCNT composite hydrogels. By adjusting the content of SCNTs from 0 to 5 wt %, TOCN-SCNT hydrogels exhibited conductivity ranging from 5.2 × 10-6 to 6.2 × 10-2 S cm-1. Just with 1 wt % incorporation of SCNTs, the hydrogel played a role in promoting the adhesive growth and proliferation of cells. The hydrogel expressed higher Connexin 43 (Cx-43) and cardiac troponin-T proteins compared with controls, demonstrating great potential in constructing a myocardial TE scaffold.

Cu-vitamin B3 donut-like MOFs incorporated into TEMPO-oxidized bacterial cellulose nanofibers for wound healing.

In this study, a novel multifunctional nanocomposite wound dressing was developed, consisting of TEMPO-oxidized bacterial cellulose (TOBC) nanofibers functionalized with donut-like copper-based metal-organic frameworks (CuVB3 MOFs). These CuVB3 MOFs were constructed using copper nodes linked by vitamin B3 molecules, resulting in a copper nicotinate crystal structure as confirmed by X-ray diffraction. Electron microscopy confirmed the presence of donut-like microstructures with uniform element distribution in the synthesized MOFs. Through the incorporation of CuVB3 MOFs into the TOBC nanofibers, innovative TOBC-CuVB3 nanocomposites were created. Biocompatibility testing using the MTT assay demonstrated enhanced cell viability of over 115% for the TOBC-CuVB3 nanocomposite. Acridine Orange staining revealed a ratio of 88-92% live cells on the wound dressings. Furthermore, fibroblast cells cultured on TOBC-CuVB3 exhibited expanded morphologies with long filopodia. The agar diffusion method exhibited improved antibacterial activity against both Gram-positive and Gram-negative bacterial strains, correlating with increased CuVB3 concentration in the samples. In vitro cellular scratch assays demonstrated excellent wound healing potential, with a closure rate of over 98% for wounds treated with the TOBC-CuVB3 nanocomposite. These findings underscore the synergistic effects of copper, vitamin B3, and TOBC nanofibers in the wound healing process.

One-pot and one-step preparation of "living" cellulose nanofiber hydrogel with active double-bond via chemical vapor deposition.

Due to the existence of water, it is still a challenge to conduct chemical modification on cellulose nanofiber (CNF) hydrogels with active double bonds. A simple one-pot and one-step method for constructing "living" CNF hydrogel with double bond was created at room temperature. The chemical vapor deposition (CVD) of methacryloyl chloride (MACl) was used to introduce physical-trapped, chemical-anchored and functional double bonds into TEMPO-oxidized cellulose nanofiber (TOCN) hydrogels. TOCN hydrogel could be fabricated within just 0.5 h, the minimum dosage of MACl could be reduced to 3.22 mg/g (MACl/TOCN hydrogel). Furthermore, the CVD methods showed high efficiency for mass production and recyclability. Moreover, the chemical "living" reactivity of the introduced double bonds were verified by the freezing and UV crosslinking, radical polymerization and thiol-ene click reaction. Compared with pure TOCN hydrogel, the obtained functionalized TOCN hydrogel exhibited remarkable improvements in mechanical properties, with enhancements of 12.34 times and 2.04 times, as well as an increase in hydrophobicity by 2.14 times and a fluorescence performance improvement of 2.93 times.

Modulation of composite hydrogel consisting of TEMPO-oxidized cellulose nanofibers and cationic guar gum.

The applications of hydrogels are prominently affected by the modulation of their structure and performance. We herein systematically implemented the modulation of an all-polysaccharide hydrogel consisting of TEMPO-oxidized cellulose nanofibers (TOCN) and cationic guar gum (CGG). Four different factors including the carboxylate content and size of TOCN, the freezing-thawing treatment and solid content of hydrogel were studied to disclose their influence on the structure and property of TOCN/CGG hydrogel. The results indicated that the increase of carboxylate content of TOCN, the number of freezing-thawing cycles and solid content all increased the crosslinking density of hydrogel as a result of the improved interactions. Accordingly, the hydrogels exhibited more compact structures and enhanced rheological properties. The influence of TOCN size on the hydrogel structure and property was demonstrated to be dependent on the compromise between the exposed functional groups of TOCN and their ability in generating entanglements inside the hydrogel. This work helps shed light on the modulation of hydrogel structure and performance, which might facilitate the exploration of hydrogel applications.

Ionic liquid-mediated regeneration of cellulose dramatically improves decrystallization, TEMPO-mediated oxidation and alkyl/alkenyl succinylation.

This work demonstrated a successful strategy that simple ionic liquids (ILs) mediated pretreatment could effectively reduce crystallinity of cellulose from 71 % to 46 % (by C2MIM.Cl) and 53 % (by C4MIM.Cl). The IL-mediated regeneration of cellulose greatly promoted its reactivity for TEMPO-catalyzed oxidation, which the resulting COO- density (mmol/g) increased from 2.00 for non-IL-treated cellulose to 3.23 (by C2MIM.Cl) and 3.42 (C4MIM.Cl); and degree of oxidation enhanced from 35 % to 59 % and 62 %, respectively. More significantly, the yield of oxidized cellulose increased from 4 % to 45-46 %, by 11-fold. IL-regenerated cellulose can also be directly subjected to alkyl/alkenyl succinylation without TEMPO-mediated oxidation, producing nanoparticles with properties similar to oxidized celluloses (55-74 nm in size, -70-79 mV zeta-potential and 0.23-0.26 PDI); but in a much higher overall yield (87-95 %) than IL-regeneration-coupling-TEMPO-oxidation (34-45 %). Alkyl/alkenyl succinylated TEMPO-oxidized cellulose showed 2-2.5 times higher ABTS* scavenging ability than non-oxidized cellulose; however, alkyl/alkenyl succinylation also resulted in a significant decline in Fe2+ chelating property.

Understanding viscoelastic behavior of hybrid nanocellulose film based on rheological and electrostatic observation in blended suspension.

The effects of TEMPO-mediated oxidized cellulose nanofibril (TOCN) on the viscoelastic behavior and phase of cellulose nanocrystal (CNC) in suspension and film were investigated using polarized optical microscopy, rotational rheometry, and dynamic mechanical analysis. The sodium cation from TOCN changed the electrostatic state of CNC by screening the CNC surface charge. The volume inflation of TOCN locally increased the CNC concentration in the suspension. In turn, the CNC-CNC interactions increased the viscosity and the yield stress. Based on the experimental observation, the changing mechanisms of electrostatic state and particular interaction in the TOCN/CNC suspensions were suggested. In the hybrid film, the time dependency of complex moduli was changed owing to the different networking between CNCs and TOCNs. The CNC-CNC contacts easily collapsed by strain, while the TOCN-TOCN entanglements were slowly altered. This study provides a fundamental understanding of CNC behavior for optimizing processes and composite properties.

Tuning of water resistance and protein adsorption capacity of porous cellulose nanofiber particles prepared by spray drying with cross-linking reaction.

Porous particles composed of 2,2,6,6-tetramethylpiperidinyl-1-oxyl-oxidized cellulose nanofiber (TOCN) as building block, i.e., porous TOCN particles, are attracting attention due to their environmental friendliness, superior properties, such as easy handling, large surface area, and high adsorption capacity. However, the instability of TOCNs in aqueous environments limits their applications. An effective solution to improve water resistance of TOCN particles is to reduce the hydrophilicity of TOCNs by forming chemical bonds with a cross-linker. In this study, Carbodilite, a common, easy-to-use, commercially available cross-linker with carbodiimide groups, was used to investigate a chemical cross-linking strategy for porous TOCN particles prepared by spray drying. The water resistance of cross-linked TOCN particles was evaluated through morphological observation by SEM images. The presence of polycarbodiimide significantly increased water resistance of cross-linked TOCN particles up to 24 h. This study demonstrates the trade-off between water resistance and adsorption efficiency according to cross-linker concentrations. These data are useful for interface science of TOCNs in liquids, assisting in controlling specific properties of porous TOCN particles for particular applications in adsorption and separation.

Grafting natural nicotinamide on tempo-oxidized cellulose nanofibrils to prepare flexible and transparent nanocomposite films with fascinating mechanical strength and UV shielding performance.

Light pollution from ultraviolet (UV) radiation is gaining growing concerns, as the emissions and burning of fossil fuels destroyed the ozone layer. Seeking a solution against skin exposure to excessive radiation is an urgent requirement. In this study, nicotinamide (NA), the main component of vitamin B3, was introduced as a new modifier into Tempo-oxidized cellulose nanofibrils (TOCNFs) together with the physical cross-linking with tannin acid (TA) to improve anti-UV performance of the nanocomposite films. Incorporation of NA into the films presents distinguished UV shielding capability UVB wavelength range from 200 nm to 320 nm (NTA1-5) due to the introduced functional groups like CO and benzene rings. Moreover, mechanical properties were notably enhanced, which overcome the low strength of common nanocellulosic materials. The stress increased from 69.8 MPa to 116.3 MPa, and the toughness can reach 131.58 MJ/m3 by tuning the additional amount of NA. Meanwhile, TGA and DTG analysis demonstrated that the incorporation of amide bonds and TA into the composite films greatly improved the thermal stability. Thus, the proposed materials fabricated from natural biomolecules show great potential in serving as new kinds of UV-resistant products in the application areas of sunscreen, protective clothing, and building materials.

TEMPO-oxidized cellulose for in situ synthesis of Pt nanoparticles. Study of catalytic and antimicrobial properties.

In this work, platinum nanoparticles (PtNPs) were synthesized by a modified polyol process using TEMPO-oxidized nanocellulose (TOCN) as a stabilizing and co-reducing agent. Different ratios of TOCN nanocellulose to Pt4+ ions were studied to establish the optimum stabilizing effect of PtNPs. The effect of different pH of aqueous TOCN suspensions on the morphology of PtNPs was also examined. It was proved that PtNPs can be obtained solely in the presence of TOCN without the use of an additional reducing agent or ethylene glycol. The morphology and structural properties of the nanocellulose­platinum nanoparticles composites were assessed using spectroscopic, microscopic and diffraction techniques, The catalytic performance in 4-nitrophenol reduction was evaluated. Significant differences in reaction rate constants k were found depending on the pH of the TOCN suspension applied during Pt4+ reduction. The crucial effect of reaction conditions on PtNPs performance was confirmed in tests of antibacterial efficacy against E. coli.