Introduction Of Silver Nanoparticles Research Articles

Toxicological Effects of Colloidal Silver Nanoparticles on Rat Health: Assessing Physiological, Hematological, Biochemical, and Behavioral Parameters

Introduction: Nanotechnology, a rapidly evolving field, has introduced silver nanoparticles (AgNPs) as promising materials with diverse applications. Their unique properties have revolutionized industries, raising concerns about potential health implications. This study aims to comprehensively evaluate the toxicological effects of AgNPs on rat health through a multidimensional approach, encompassing physiological, hematological, biochemical, and behavioral assessments. Methodology: Colloidal AgNPs with a minimum purity of 99.98% were synthesized using an inductive coupled plasma (ICP) method. Sixty male specific-pathogen-free (SPF) Wistar rats were exposed to low (10 μg/kg/day) and high (100 μg/kg/day) doses of AgNPs, alongside a control group. Throughout the exposure period, comprehensive assessments, including body weight changes, food intake, water consumption, hematological and biochemical parameters, and behavioral evaluations, were systematically conducted. The statistical analysis employed a combination of one-way ANOVA and Kruskal-Wallis tests for robust data interpretation. Results: Rats exposed to low (10 μg/kg/day) and high (100 μg/kg/day) doses of AgNPs displayed no significant changes in food intake, water consumption, or blood parameters compared to the control group. However, a notable reduction in body weight was observed in the high-dose group, suggesting a potential dose-dependent impact. Biochemical analyses indicated no significant differences in liver and kidney function parameters for the low-dose group, but the high-dose group exhibited potential elevation in liver enzymes, necessitating further scrutiny. Behavioral assessments revealed no significant alterations in open-field behavior or cognitive function, indicating minimal impact on exploratory and cognitive abilities within the tested doses. Conclusion: AgNPs demonstrated minimal impact on certain parameters, the high-dose group exhibited notable body weight reduction and potential liver enzyme alterations, warranting further investigation. Behavioral assessments indicated no significant cognitive effects. These findings emphasize the importance of continued research for informed regulatory decisions and the safe utilization of AgNPs in consumer products.

Synthesis and characterization of n-isopropylacrylamide based copolymers with silver nanoparticles

In recent years, the so-called "smart" polymers, which can systematically respond to small environmental changes, such as pH, temperature and electric field, are widely used in many fields. Researchers are particularly interested in using drugs to transport to the right place in the human body. One of the types of these smart polymers are thermosensitive polymers. Among the thermosensitive polymers, the most well-known are homo- and copolymers based on N-isopropylacrylamide. In the research work, in order to improve the properties of thermosensitive polymers, silver nanoparticles were added to the hydrogel composition. Hydrogels based on N-isopropylacrylamide and 2-hydroxyethylacrylate monomers were synthesized by radical polymerization in solution (in H2O and AgNO3 solution). While the production of silver nanoparticles is based on the redox (by NaBH4 solution) mechanism, the formation of these nanoparticles in the gel was carried out by diffusion. While the introduction of silver nanoparticles into the gel was controlled by ultraviolet spectroscopy, its inclusion in the gel was confirmed using a scanning electron microscope (SEM). Meanwhile, a hydrogel containing silver nanoparticles exhibits antibacterial properties, it was investigated using biomedical tests. It has been shown here that a hydrogel containing silver has good antibacterial properties, whereas a hydrogel without silver does not have the ability to destroy bacteria.

Promising way for enhancing light absorption in silicon via silver nanoparticles: experimental and numerical study

Silver nanoparticles (Ag-Nps) were grown on the surface of a p-type crystalline silicon (C-Si) substrate using electroless metal deposition. It was found that the Ag-Nps distribution on C-Si was controlled by the silver nitrate (AgNO3) concentrations. Atomic force microscopy observations revealed the formation of a continuous layer at high concentration. In contrast, a distribution of Ag-Nps with a spherical shape was obtained at lower concentration. The samples were also examined by optical microscopy under dark field illumination. The light reflected from Ag-Nps was obtained with different colors. This difference indicates a slight change in particle size. It is demonstrated that a silicon substrate with deposited Ag-Nps shows a significant decrease in reflectance and an increase of the absorption in the region from 200 to 800 nm. Moreover, the behavior of small Ag-Nps while interacting with light (absorbed or scattered light) is theoretically described using the Mie theory based on the Drude model. The introduction of silver nanoparticles on silicon surface is used to improve the efficiency of solar cells by reducing reflection and increasing the light absorption.

Modification of AgNP-Decorated PET: A Promising Strategy for Preparation of AgNP-Filled Nuclear Pores in Polymer Membranes.

Polymer-based membranes represent an irreplaceable group of materials that can be applied in a wide range of key industrial areas, from packaging to high-end technologies. Increased selectivity to transport properties or the possibility of controlling membrane permeability by external stimuli represents a key issue in current material research. In this work, we present an unconventional approach with the introduction of silver nanoparticles (AgNPs) into membrane pores, by immobilising them onto the surface of polyethyleneterephthalate (PET) foil with subsequent physical modification by means of laser and plasma radiation prior to membrane preparation. Our results showed that the surface characteristics of AgNP-decorated PET (surface morphology, AgNP content, and depth profile) affected the distribution and concentration of AgNPs in subsequent ion-track membranes. We believe that the presented approach affecting the redistribution of AgNPs in the polymer volume may open up new possibilities for the preparation of metal nanoparticle-filled polymeric membranes. The presence of AgNPs on the pore walls can facilitate the grafting of stimuli-responsive molecules onto these active sites and may contribute to the development of intelligent membranes with controllable transport properties.

Engineering a separation membrane containing a gel layer with backbone support effect and bionic-inspired capillary effect for the efficient separation of dyes/salts

Accurate separation of dyes/salts is a crucial step in the treatment of dye-containing wastewater. Therefore, separation membranes with high permeability and high dye/salt selectivity are urgently required. In this study, an ultrathin gel layer of carboxymethyl cellulose was constructed on a poly(vinylidene fluoride) membrane surface. This gel layer contains a backbone support structure and provides the bionic-inspired capillary effect, which endows the membrane with the capability to realize the efficient separation of dyes and salts. The introduction of silver nanoparticles (Ag NPs) into the gel layer provides a skeleton support structure, which prevents the collapse of the gel layer, reduces the actual separation layer thickness, and decreases the mass transfer resistance. Moreover, the formation of capillaries between the numerous Ag NPs facilitates the rapid penetration of water molecules. Interestingly, this membrane exhibited excellent selectivity for dye/salt separation (dye removal >99.5 %, salt removal <10 %) while maintaining an exceptionally high water permeate flux (244.5 L/m2h). Moreover, the membrane exhibited excellent stability. This study demonstrates that the construction of organic/inorganic three-dimensional structures with capillary and skeletal support effects show promise potential for modification of dye/salt separation membranes.

Phyto-synthesis of silver nanoparticles from Plumeria pudica leaf extract and its application in anti-cancerous activity

In this study, we have developed an environment friendly and novel approach for the synthesis of silver nanoparticles utilising plumeria pudica leaf extract. In this technique, the leaf extract was employed as both a reducing agent for the reduction of a silver nitrate (AgNO3) solution and a capping agent, leading to the synthesis of silver nanoparticles (Ag NPs). The outcomes of these analyses revealed an average particle size of ∼19 nm as determined by SEM, while XRD measurements indicated a crystalline domain size of ∼12 nm and a lattice parameter of approximately 4.087467 Å. Furthermore, the anti-cancer potential of the synthesised silver nanoparticles was evaluated, unveiling an IC50 value of around 28 µM. This suggests that the introduced silver nanoparticles may have triggered apoptosis, consequently inducing cell death. These findings underscore the potential of utilising environmentally benign silver nanoparticles in lung cancer chemotherapy.

Investigating the effect of anode materials on the performance and microbial community in an integrated chamber-free microbial fuel cell

Conventionally, there are two basic configurations for microbial fuel cell (MFC), one with anode and cathode chambers, as known as dual-chamber MFC, one with only anode chamber and a air–cathode, called single-chamber MFC. However, electrode materials' complex configuration and high resistance limit their practical applications in power generation and wastewater purification. To this end, we constructed three MFCs using carbon felt, Ni/Ti, and Ag-Ni/Ti as anodes based on our previously constructed integrated chamber-free MFC (iMFC). After 21 days of operation, the Ag-Ni/Ti-MFC performed best in bioelectricity output and removal of target pollutants. The bioelectricity output parameters were an open-circuit voltage of 0.773 V, a maximum current density of 552.1429 mA/m2, and a power density of 426.8064 mW/m2. Furthermore, the MFC achieved removals of 67.90% for the chemical oxygen demand (COD), 55.20% for total nitrogen (TN), and 61.83% for ammonia nitrogen (NH3-N). Introducing silver nanoparticles to the transmembrane and outer membrane boosted the charge extraction efficiency in the MFCs. Moreover, 16S rDNA analysis indicated that typical electricity-producing bacteria, including Comamonas, Paraclostridium, and Asaccharospora, had a higher relative abundance in the Ag-Ni/Ti-MFC anode than in other anodes. Overall, the surface structure of different anode materials plays a critical role in bioelectricity generation and wastewater purification using iMFC by affecting the mass transfer of substrates and metabolites.

A nanofiber Murray membrane with antibacterial properties for high efficiency oily particulate filtration

Particulate air pollution represented by PM2.5 is one of the biggest environmental challenges in the 21st century. Especially in 2020, the global outbreak of COVID-19 has brought new challenges to melt-blown filter materials, such as the attenuation of filtration efficiency with breathing, even no filtration effect for viruses as their smaller diameter, the sharp decline of filter efficiency after oily filtration cycle, and its limit in some explosive occasions. Here, using the diameter difference of polystyrene (PS), polyvinylidene fluoride (PVDF) and nylon 6(PA6) fibers, we report a multistage structure nanofiber membrane (PS/PVDF/PA6&Ag MSNMs) with high efficiency, low resistance and antibacterial effect by constructing gradient pore structure and introducing silver nanoparticles (Ag NPs), overcoming the above defects. The average filtration efficiency of PS/PVDF/PA6&Ag MSNMs for diisooctyl sebacate (DEHS) monodisperse particles from 0.2 μm to 4.9 μm was 99.88%, and the pressure drop was only 128 Pa. After repeated circulation for 100 times, the filtration efficiency and pressure drop remained stable. Above all, the antibacterial nanofiber membrane with high efficiency and low resistance has been preliminarily constructed, the future research will further focus on the performance after circulation.

Facile design of antibacterial sheets of sacran and nanocellulose

Synthetic materials cause considerable damage over long-term usage. Therefore, the multiple benefits of naturally-derived polymers are being acknowledged for sustainable material fabrication. We prepared hybrid hydrogel sheets of polysaccharides, sacran and nanocellulose as soothing wound dressings. Antibacterial activity was purveyed by introducing silver nanoparticles in the polysaccharide blend; it was further dried to a film and subsequently crosslinked via thermal annealing. This step provided physical-crosslink junctions in the matrix and firm lodging of the nanoparticles. At the same time, use of harmful chemicals was circumvented. The silver nanoparticle–polysaccharide hydrogels significantly reduce the viability of different bacteria and can potentially be applied as on-demand dressings.

Photocatalytic activity of the TIO2/Ag/rGO nanocomposite

The paper presents the results of a study of the photocatalytic activity of films formed by titanium dioxide nanorods doped with silver nanoparticles and reduced graphene oxide. The obtained nanocomposite materials were studied by optical spectroscopy, scanning electron microscopy, X-ray diffractometry, and Raman spectroscopy. The photocatalytic activity of the samples was evaluated by generating a photocurrent when the surface was illuminated by a modulated light source of a xenon lamp. In addition, the photocatalytic activity of the samples was evaluated by the degradation of the methylene blue dye, which is a model. It was found that the introduction of silver nanoparticles and reduced graphene oxide into the pores of films made of titanium dioxide nanorods leads to an increase in the spectral sensitivity of the sample in the region of 400-500 nm. The increased sensitivity of the sample to visible light leads to an increase in photocurrent generation and is 2.3 times higher than that of the original sample. Degradation of the methylene blue dye after 100 minutes of irradiation in the presence of a TiO2/Ag/rGO sample was 19 %. This is 3 times higher than in TiO2 nanorods films and 2.3 times higher than TiO2/Ag films. The results of the conducted studies have shown that the improvement of photocatalytic activity is associated with a decrease in film resistance, an expansion of spectral sensitivity and an increase in the surface area of the nanorods.

Luminescence property in Er3+/Tm3+/Ag NPs doped tellurite glass applied for broadband amplifier

In this study, tellurite glasses co-doped with Er3+/Tm3+ were synthesized through the melt-quenching technique. Under 808 nm excitation, the spectral overlap of 1.53 µm band fluorescence generated by the transition of Er3+:4I13/2→4I15/2 and 1.47 µm band fluorescence generated by the transition of Tm3+:3H4→3F4 achieved the near-infrared (NIR) broadband flat fluorescence emission in the range of 1350–1650 nm, in which the most flat fluorescence emission was achieved when the doping amount of Er2O3 and Tm2O3 was 0.1 and 0.8 mol%, respectively, and the full width at half maximum (FWHM) reached 161 nm. Subsequently, the NIR fluorescence intensity was enhanced by introducing silver nanoparticles (Ag NPs) based on broadband flat fluorescence emission. The optimal conditions conducive to broadband fluorescence enhancement were explored by changing the heat-treated time that could affect the formation and growth of Ag NPs. When the amount of AgCl is 0.5 mol%, tellurite glass co-doped with Er3+/Tm3+ ions heat-treated at temperature 410 ℃ for 6 h has the best enhancement effect of 81 %. After transmission electron microscopy (TEM) measurement, the introduced Ag NPs’ diameter at this time is about 18 nm. Some important spectral parameters of Er3+ and Tm3+ ions, for instance the radiative transition probability together with radiative lifetime were calculated from the absorption spectra according to the Judd-Ofelt theory. Structural characteristics based on X-ray diffraction analysis and thermal stability based on differential scanning calorimeter analysis was presented. Based on the above research, the enhanced broadband and flat fluorescence in the 1350–1650 nm range is of great significance for the application of broadband optical amplifiers in modern WDM networks.

Dual-action silver functionalized nanostructured titanium against drug resistant bacterial and fungal species

HypothesisTitanium and its alloys are commonly used implant materials. Once inserted into the body, the interface of the biomaterials is the most likely site for the development of implant-associated infections. Imparting the titanium substrate with high-aspect-ratio nanostructures, which can be uniformly achieved using hydrothermal etching, enables a mechanical contact-killing (mechanoresponsive) mechanism of bacterial and fungal cells. Interaction between cells and the surface shows cellular inactivation via a physical mechanism meaning that careful engineering of the interface is needed to optimse the technology. This mechanism of action is only effective towards surface adsorbed microbes, thus any cells not directly in contact with the substrate will survive and limit the antimicrobial efficacy of the titanium nanostructures. Therefore, we propose that a dual-action mechanoresponsive and chemical–surface approach must be utilised to improve antimicrobial activity. The addition of antimicrobial silver nanoparticles will provide a secondary, chemical mechanism to escalate the microbial response in tandem with the physical puncture of the cells. ExperimentsHydrothermal etching is used as a facile method to impart variant nanostrucutres on the titanium substrate to increase the antimicrobial response. Increasing concentrations (0.25 M, 0.50 M, 1.0 M, 2.0 M) of sodium hydroxide etching solution were used to provide differing degrees of nanostructured morphology on the surface after 3 h of heating at 150 °C. This produced titanium nanospikes, nanoblades, and nanowires, respectively, as a function of etchant concentration. These substrates then provided an interface for the deposition of silver nanoparticles via a reduction pathway. Methicillin-resistant Staphylococcous aureus (MRSA) and Candida auris (C. auris) were used as model bacteria and fungi, respectively, to test the effectiveness of the nanostructured titanium with and without silver nanoparticles, and the bio-interactions at the interface. FindingsThe presence of nanostructure increased the bactericidal response of titanium against MRSA from ∼ 10 % on commercially pure titanium to a maximum of ∼ 60 % and increased the fungicidal response from ∼ 10 % to ∼ 70 % in C. auris. Introducing silver nanoparticles increased the microbiocidal response to ∼ 99 % towards both bacteria and fungi. Importantly, this study highlights that nanostructure alone is not sufficient to develop a highly antimicrobial titanium substrate. A dual-action, physical and chemical antimicrobial approach is better suited to produce highly effective antibacterial and antifungal surface technologies.

Flexible, Strong and Multifunctional Anf@Ag Nanocomposite Film for Human Physiology and Motion Monitoring

To expand the application range of flexible pressure sensors, endowing them with multifunction capabilities becomes extremely important. Herein, a flexible, strong and multifunctional nanocomposite film was prepared by introducing silver nanoparticles (Ag NPs) into aramid nanofiber (ANF) film using a simple two-step vacuum filtration method. When the Ag content was 27.6 vol%, the electrical resistance of the resulting ANF@Ag nanocomposite film was as low as 1.63 Ω/cm2, and the water contact angle of the nanocomposite film reached 153.9 ± 1°. Compared to the ANF film, the tensile strength of the nanocomposite film increased from 55 MPa to 66.3 MPa with an increase of 20.5%. After being applied to the human body, the nanocomposite film served as a pressure sensor that was able to recognize different stimuli for healthcare monitoring. Based on the advantages, it may become a potential candidate for electronic skin, intelligent wearable devices and medical detection equipment.

Dendritic Fibrous Colloidal Silica Internally Cross-linked by Bivalent Organic Cations: An Efficient Support for Dye Removal and the Reduction of Nitrobenzene Derivatives.

We designed a new unique amphoteric monodisperse colloid with a large complex internal structure, in which silica surfaces are bridged with an organic cross-linker. The rationale was that such colloids would be excellent adsorbents for cationic and anionic dyes and, when doped with noble metal nanoparticles, would be an excellent catalyst for the reduction of a variety of organic compounds. In the first step, the organo-silica bridging agent (bivalent organic cross-linkers) DABCO-S (silanated DABCO) was prepared through a simple nucleophilic substitution reaction between (3-chloropropyl)triethoxysilane and bivalent 1,4-diazabicyclo[2.2.2]octane (DABCO) (a strong base). In the second step, a DABCO-S bridge was introduced into dendritic fibrous nanostructured colloidal silica (DFNS) under open-vessel reflux conditions. We refer to the product obtained by incorporating DABCO-S in DFNS as DDS. The unique characteristics of DFNS are completely preserved in this new type of periodic mesoporous organo-silica-DFNS. The produced nanocomposite has a high surface area of about 807 m2 g-1, a large pore volume of 1.9 cm3 g-1, and a bimodal pore size distribution, with small 2.5 nm pores and large 30 nm pores. As such, DDS is an efficient adsorbent for dye removal from wastewater. The results show that DDS can adsorb positive and negative dyes such as methylene blue, orange II sodium salt (OR), and procion red mx-58 (PR) with a capacity of 678, 3192, and 3190 mg dye/g adsorbent. Introducing silver nanoparticles in situ into DDS leads to a composite with excellent accessibility of reactants to the Ag surface, resulting in an efficient catalytic reduction of nitro aromatic compounds (NACs) in aqueous media.

Chitosan/Silver Nanoparticle/Graphene Oxide Nanocomposites with Multi-Drug Release, Antimicrobial, and Photothermal Conversion Functions.

In this work, we designed and fabricated a multifunctional nanocomposite system that consists of chitosan, raspberry-like silver nanoparticles, and graphene oxide. The room temperature atmospheric pressure microplasma (RT-APM) process provides a rapid, facile, and environmentally-friendly method for introducing silver nanoparticles into the composite system. Our composite can achieve a pH controlled single and/or dual drug release. Under pH 7.4 for methyl blue loaded on chitosan, the drug release profile features a burst release during the first 10 h, followed by a more stabilized release of 70–80% after 40–50 h. For fluorescein sodium loaded on graphene oxide, the drug release only reached 45% towards the end of 240 h. When the composite acted as a dual drug release system, the interaction of fluorescein sodium and methyl blue slowed down the methyl blue release rate. Under pH 4, both single and dual drug systems showed a much higher release rate. In addition, our composite system demonstrated strong antibacterial abilities against E. coli and S. aureus, as well as an excellent photothermal conversion effect under irradiation of near infrared lasers. The photothermal conversion efficiency can be controlled by the laser power. These unique functionalities of our nanocomposite point to its potential application in multiple areas, such as multimodal therapeutics in healthcare, water treatment, and anti-microbials, among others.

An efficient textile-based electrode utilizing silver nanoparticles/reduced graphene oxide/cotton fabric composite for high-performance wearable supercapacitors

An efficient textile-based electrode was successfully prepared by introducing silver nanoparticles (AgNPs) on the surface of reduced graphene oxide (RGO) coated cotton fabric (CF) using a simple, cost-effective, room-temperature, rapid, and scalable electroless plating method. The Ag/RGO coated CF showed a high specific capacitance of 426±10 F/g in 0.5 M NaOH electrolyte during the CV cycles. Symmetric supercapacitor cells based on Ag/RGO/CF composite possessed outstanding cycle life (126% retention of initial specific capacitance after 1000 charge-discharge cycles) and good rate capability. The coating layer of RGO endows the electrode an excellent electrical conductivity, high surface area, and good electrical double-layer capacitance. Simultaneously, the electroless plating of silver improves the capacitive behavior due to an increase of conductivity and induce the pseudocapacitive effects. Hence, beneficial synergistic effects of RGO, AgNPs, and 3D hierarchical structure of CF lead to an excellent energy storage performance. The all-solid-state flexible symmetric supercapacitor was assembled using this composite textile, which exhibited high electrochemical performance stability under mechanical bending (89% of initial capacitance retained after 1000 bending cycles) and delivered energy density as high as 34.6 Wh kg−1 (at a power density of 125 W kg−1). Therefore, this novel and high-performance electrode is a promising candidate for the next-generation wearable supercapacitors.

9.05% HTM free perovskite solar cell with negligible hysteresis by introducing silver nanoparticles encapsulated with P4VP polymer

This study is a follow up to our previously published manuscript on “improved power conversion efficiency in Perovskite solar cell using silver nanoparticles modified photoanode”. Three more photoanodes were fabricated which are: Ag@P4VP NPs mixed with perovskite layer (S2), Ag@P4VP NPs simultaneously mixed both in TiO2 and perovskite films (S3) and P25 NP simultaneously mixed both in TiO2 and perovskite absorber (S4) and their performances were investigated systematically. The performance, especially the photocurrent, and open circuit voltage of PSCs made of Ag@P4VP NPs were significantly affected. The champion device is S3, which shows enhancement in power conversion efficiency (PCE) from 3.80 to 9.05%, short circuit current density (Jsc) from 11.04 to 15.87 mA cm−2, open circuit voltage (Voc) from 0.85 to 0.88 and fill factor (FF) from 0.41 to 0.65, which demonstrates ~ 2.38 times improvement in PCE over the control device (C). When Ag@P4VP NPs was mixed with TiO2, PCE of 5.69%, Jsc of 12.61 mA cm−2, Voc of 0.88 V and FF of 0.51 were achieved, which shows ~ 1.50 times improvement over the performance of the reference cell. Also, when Ag@P4VP NPs was mixed with the perovskite layer, PCE of 8.08%, Jsc of 14.18 mA cm−2, Voc of 0.89 V and FF of 0.64 were achieved, which shows ~ 2.13 times improvement over the performance of the pristine device. The addition of Ag@P4VP NPs enhanced exciton generation and dissociation, encouraging charge separation/transfer, as well as reducing quenching losses. For the hysteresis test, it was found that the devices with Ag@P4VP NPs have almost identical J–V curves with negligible hysteresis, which is attributed to the significant reduction of the trap density of the perovskite film when Ag@P4VP NPs is incorporated to fill the pores with high trapping rate. We however observed hysteretic behavior in devices C and S4, which makes it difficult to estimate the real PCE.

Chitosan-Based Composite Nanosilver Gel Application in Nursing Care of Intensive Care Unit Patients with Severe Burns

Burns are the most common clinical disease in daily life. Burn wounds are vulnerable to bacterial infection due to factors such as edema, hypoxia, and ischemia. However, traditional antibacterial supplements do not achieve satisfactory nursing results. Here, we use chitosan as a carrier by introducing silver nanoparticles (AgNPs) and recombinant human epidermal growth factor (rhEGF) together. We have constructed a new type of high moisture retention, high oxygen permeability, high-efficiency chitosan-nanosilver@recombinant human epidermal growth factor (CSAgNPs@ rhEGF) antibacterial hydrogel dressing. The clinical trials showed that the antibacterial effect of CS-AgNPs@rhEGF hydrogel dressings against Pseudomonas aeruginosa (Pa.) and Staphylococcus epidermidis (Se.) was significantly better than that of petroleum jelly and 1% silver sulfadiazine (1%-SSD). In addition, rhEGF promoted tissue cell proliferation and repair. Thus, the CS-AgNPs@rhEGF hydrogel dressing can significantly improve the wound healing rate and healing time in patients with severe burns compared with traditional dressings. Thus, CS-AgNPs@rhEGF hydrogel dressing is expected to provide a new choice for clinical burn patients to prevent wound infection and tissue repair, and has a broad prospect in burn wound healing.

Antibacterial and Immunomodulating Activity of Silver Nanoparticles on Mice Experimental Tuberculosis Model

The antibacterial activity of silver nanoparticles with a size of 43.6 ± 10.7 nm against strain Mycobacterium tuberculosis H37Rv was studied in vitro (the studied concentrations of silver nanoparticles were 0.1; 1; 10; 25, and 50 μg/mL) and in an experimental murine model of chronic tuberculosis. It was shown that silver nanoparticles at a concentration of 50 μg/mL suppress mycobacterial growth in vitro by 2 times. The administration of silver nanoparticles via inhalation at a dose of 0.1 mg/kg to tuberculosis-infected mice resulted in a twofold decrease in the colonization of the lungs and spleens by M. tuberculosis. In these animals, the quantity of protein in the broncho-pulmonary lavage fluid was reduced by two times, to 1908.5 ± 105.7 (P < 0.001), which indicates a decrease in the inflammatory processes in the lungs. The level of the production of reactive oxygen species by neutrophils increased, reflecting their bactericidal potential, which was reduced by 2.7 times before treatment as compared to the control group of animals (P < 0.001). After the introduction of silver nanoparticles, a recovery in the ratio of lymphocyte populations in the spleen and cytokine balance was observed. It was expressed by a decrease in the levels of IFN-γ, TNF-α, and IL-4 in the blood serum and broncho-pulmonary lavage fluid in TB mice. Thus, it was shown for the first time that the inhalation of silver nanoparticles stabilized with polyvinylpyrrolidone led not only to a noticeable bactericidal effect but also recovered the balance of the immune system of mice.

Size-Dependent Uptake and Distribution of AgNPs by Silkworms

Silk is an attractive natural fiber due to its excellent mechanical properties and biocompatibility. Xenobiotic modification of pristine silk is gaining significant attention to meet specific demands. The silk payload of xenobiotics is affected by their uptake efficiency, biodistribution, metabolism, and excretion. Herein, we systematically evaluated the effect of the nanoparticle size (20–100 nm) on the biodistribution and silk production by introducing silver nanoparticles (AgNPs) into the silkworm diet. Interestingly, the silk payload of AgNPs is highly dependent on their overall size, where 50 nm AgNPs are prone to accumulate in silk glands and reveal the highest content in the produced silk, qualifying silk antibacterial activity against both Gram-positive and Gram-negative bacteria. These findings provide new insights to understand how nanoparticle properties influence the incorporation of nanomaterials into silk and can help optimize the material design.