Encapsulated Silver Nanoparticles Research Articles

Supramolecular-assisted nanocomposite coatings with sustainable and robust resistance to microbially mediated biofouling and corrosion

Surface-adhering biofilms contribute significantly to irreversible biofouling and corrosion, presenting a multi-trillion-dollar annual problem in public health and industry. Strategies employing antibacterial elements are emerging to fabricate multifunctional coatings that effectively combat such microbially produced damage. However, rapid, reliable, and robust surface engineering remains challenging due to stability limitations and intricate anti-biofilm additive dynamics. Herein, a silver-capsule-conjugated polyurethane coating with high stability and antimicrobial efficacy in a cooperative manner is developed through controlled supramolecular self-assembly. Polyvinylpyrrolidone (PVP)-mediated molecule entanglement breaks through the incompatibility between polymeric components and nanomaterials, strengthening the dispersion and fixation of encapsulated silver nanoparticles. The facilitation and control of the nanoscale interfacial binding significantly suppresses the aggregation of inorganic nanoparticles and consequent microcracks development, giving rise to mechanical robustness and thermal stability of the hybrid coating under extreme conditions. A synergistic combination of exposed residues, electrostatic, and coordination interactions could readily integrate the resultant coating on virtually arbitrary material surfaces. This composite coating exhibits broad-spectrum and high bactericidal efficiencies of 99.99 % against Staphylococcus aureus and Escherichia coli, as well as excellent biofilm formation suppression. Moreover, our coating has robust resistance to microbial-influenced corrosion (MIC) and can even endure 720 h of salt spray. This study deciphers a general code for creating stable and durable nanohybrid coatings to mitigate microbially related risks.

Broadband, Plasmon‐Modified SnSe2 Photodetector Based on LNOI Thin‐Film Platform

AbstractLithium niobate on insulator (LNOI) is widely recognized as an essential optoelectronic integration platform due to its unique ferroelectric properties and photorefractive effect. However, the wide bandgap and weak absorption of lithium niobate limit its further application in integrated photodetection field. To address this issue, encapsulating silver nanoparticles within the LNOI structure are proposed to manipulate the light field distribution of modified lithium niobate through the localized surface plasmon resonance (LSPR) effect and utilize the modified lithium niobate thin film as a functional substrate to tailor the optoelectronic properties of surface SnSe2 nanosheets, significantly enhancing their photodetection capabilities. The photocurrent of the SnSe2 photodetector based on LNOI with embedded Ag nanoparticles is enhanced by up to 1912 times compared to that on the original LNOI under the same conditions, which represents the highest reported plasmonic‐induced photodetection enhancement. This work deepens the basic research on plasmonic‐modified 2D materials and ferroelectric materials, which promotes the development of on‐chip photodetectors and the realization of fully functional photonic circuits that integrate all essential components on a single chip.

All-aqueous microfluidic printing of multifunctional bioactive microfibers promote whole-stage wound healing

Wound healing involves multi-stages of physiological responses, including hemostasis, inflammation, cell proliferation, and tissue remodeling. Satisfying all demands throughout different stages remains a rarely addressed challenge. Here we introduce an innovative all-aqueous microfluidic printing technique for fabricating multifunctional bioactive microfibers, effectively contributing to all four phases of the healing process. The distinctive feature of the developed microfibers lies in their capacity to be printed in a free-form manner in the aqueous-two phase system (ATPS). This is achieved through interfacial coacervation between alkyl-chitosan and alginate, with enhanced structural integrity facilitated by simultaneous crosslinking with calcium ions and alginate. The all-aqueous printed microfibers exhibit exceptional performance in terms of cell recruitment, blood cell coagulation, and hemostasis. The inclusion of a dodecyl carbon chain and amino groups in alkyl-chitosan imparts remarkable antimicrobial properties by anchoring to bacteria, complemented by potent antibacterial effects of encapsulated silver nanoparticles. Moreover, microfibers can load bioactive drugs like epidermal growth factor (EGF), preserving their activity and enhancing therapeutic effects during cell proliferation and tissue remodeling. With these sequential functions to guide the whole-stage wound healing, this work offers a versatile and robust paradigm for comprehensive wound treatment, holding great potential for optimal healing outcomes.

Fabrication of chitosan/fibrin-armored multifunctional silver nanocomposites to improve antibacterial and wound healing activities

A wound healing substitute promotes rapid tissue regeneration and protects wound sites from microbial contamination. The silver-based antiseptic frequently moist skin stains, burns and irritation, penetrates deep wounds and protects against pathogenic infections. Thus, we formulated a novel fibrin/chitosan encapsulated silver nanoparticle (CH:F:SPG-CH:SNP) composites bandage accelerating the polymicrobial wound healing. Electrospinning method was employed to form the nano-porous, inexpensive, and biocompatible smart bandages. The structural, functional, and mechanical properties were analyzed for the prepared composites. The biological capacity of prepared CH:F:SPG-CH:SNP bandage was assessed against NIH-3 T3 fibroblast and HaCaT cell lines. In vitro hemolytic assays using red blood cells were extensively studied and explored the low hemolytic effect (4.5 %). In addition, the improved drug delivery nature captured for the CH:F:SPG-CH:SNP composite bandage. Antibacterial experiments were achieved against Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus and Lactobacillus bulgaricus using zone inhibition method. Moreover, in-vivo wound healing efficacy of fabricated smart bandage was evaluated on the albino Wistar rats which revealed the significant improvement on the postoperative abdomen wounds.

Pitaya-inspired microcarrier/hydrogel composite for chronic wound healing: One-pot preparation, tailorable structures, and versatile functionalization

Development of hydrogel-based constructs that integrate active substances appears to be a promising direction for treating chronic wounds. However, their practical applications are not satisfied as expected and limited by cumbersome fabrication processes, high production costs, uncontrolled compositions, and lacking multiple functions into one platform. Herein, inspired by the structure of a pitaya, a microcarrier-embedded hydrogel-based construct is designed via one-pot microfluidic emulsification. The hydrogel matrix like the creamy white flesh of a pitaya is composed of snail mucus and alginate, possessing demanded bio-adhesion, bio-activity, and bio-compatibility. The embedded microcarriers like the small black seeds of a pitaya are composed of mesoporous silica nanoparticles and poly(lactic-co-glycolic acid), serving as an excellent device to control drug delivery. Benefited from the emulsion manipulation ability of microfluidic system, the content ratio of embedded microcarriers in hydrogel matrix, and the respective compositions of embedded microcarriers and hydrogel matrix are all variable to adapt to the individualized treatment. Importantly, the pitaya-inspired microcarrier/hydrogel composite (PMH) can be further functionalized by introducing specific actives into its hierarchical compartments. After encapsulating silver nanoparticles and angiogenic molecules into the hydrogel matrix and embedded microcarriers respectively, both in vitro and in vivo experiments demonstrate that PMH can prevent bacteria invasion, promote cell function, and accelerate wound healing under diabetic conditions with enhanced epidermis regeneration, collagen deposition, blood vessel formation, and skin function recovery. Collectively, taking advantages of its one-pot preparation, tailorable structures, and versatile functionalization, the broad application of PMH in chronic wound management and other biomedical fields is anticipated.

Silver nanoparticle incorporated calcium crosslinked hydrogel composite for reduction of methylene blue dye and nitrite sensing

The dissipative convective procedure was used, followed by the freeze-drying technique to successfully fabricate self-organized alginate/xantham gum (Alg/XG) composite materials encapsulating silver nanoparticles (AgNPs) and without nanoparticles and cross-linked with CaCl2 and prepared Alg/XG/AgNPs/Dex/Ca nanocomposite. The synthesized nanocomposite was thoroughly characterized by techniques such as Fourier transform infrared spectroscopy (FT-IR), N2 adsorption Study (BET), X-ray diffraction (XRD), Scanning electron microscopy with energy dispersive X-ray analysis (SEM-EDAX), and Transmission electron microscopy (TEM). The results revealed that Alg/XG/AgNPs/Dex/Ca composites showed remarkably porous structures with ordered capillaries. These nanocomposites were assessed for catalytic reduction of methylene blue (MB) dye. The Alg/XG/AgNPs/Dex/Ca composite competently reduced the MB dye within 50 s in the presence of NaBH4 with a rate constant of 0.31907 min−1 and also showed 98 % degradation. It was established that the reduction reaction follows pseudo-first-order kinetics. The value of △H0 is −113.85 kJ mol−1 confirmed the exothermic nature and the positive values of △S0 (259.96 J k−1mol−1) suggested good affinity of the MB dye molecules toward the absorbent. The Activation energy of the reaction is 11.65 kJ mol−1. Furthermore, as-prepared Alg/XG/Dex/AgNPs/Ca was tested for the electrochemical oxidation of nitrite, which also gave good results. It sensed the nitrite with LOD and LOQ values of 0.10 ng mL−1 and 0.36 ng mL−1, respectively, and a sensitivity of 276.4451 μA/μM/cm2 was calculated. The results reveal that synthesized nanocomposite is a promising nano-catalyst in the degradation of MB dye and the electrochemical investigation of nitrite.The use of nanoparticles-incorporated composites as catalysts opens a range of new possibilities for applications in the area of catalysis.

Tuning the energy storage performance of graphene oxide-based nanocomposite films by encapsulating silver nanoparticles

In the current designed study, we explore the dielectric and energy storage performance of silver nanoparticle decorated graphene oxide nanocomposites incorporated into chitosan blended with poly (1-vinylpyrrolidone-co-vinyl acetate) in comparison with only graphene oxide nanocomposite doped into the same blend matrix. A sustainable and eco-friendly green route approach was used to form the silver nanoparticle decorated graphene oxide nanocomposites. The nanocomposite films so fabricated using the solvent evaporation method, were subjected to various characterisation techniques such as X-ray diffraction analysis, Fourier transform infrared spectroscopy, thermal analysis, surface morphology and impedance spectroscopy. Slight decrease in crystallinity (44.3 %), difference in the positioning of infrared bands, thermal stability (up to ∼77 °C) and evenly distributed morphology depict the advantage of silver coating over graphene oxide nanoparticles in the blended nanocomposite films. A boost in the dielectric properties and energy storage ability was displayed by the silver encapsulated graphene oxide reinforced nanocomposite blend films. The dielectric properties were examined by using a Nyquist plot (Bulk resistance - 1.01 × 104 Ω). An ionic conductivity of 1.044 × 10−4 S/cm and a DC conductivity of 1.196 × 10‐−4 S/cm was observed. Of note, it can be inferred that silver nanoparticle decorated graphene oxide nanocomposites impart tremendous electrical properties to the chitosan/poly (1-vinylpyrrolidone-co-vinylacetate) films, enabling them to be used in energy storage applications.

Membrane biofouling mitigation via immobilizing AgNPs@ZIF-8 microcapsules on membrane surface for extractive membrane bioreactor

During the extractive membrane bioreactor (EMBR) process, the membrane mass transfer efficient would be significantly reduced due to the biofilm aggregation on the membrane surface. In order to mitigate the membrane biofouling, the microcapsules developed by encapsulating silver nanoparticles (AgNPs) into the zeolitic imidazolate framework-8 (ZIF-8), were immobilized on the membrane surface for the first time. The AgNPs@ZIF-8 microcapsules could ensure the well compatibility between the micromaterials and membrane surface, avoid direct exposure of AgNPs to biomass, as well as slowly release the silver ions on the membrane surface. Compared to the unmodified membrane #M0 (declined to 55% of its initial value) and ZIF-8 modified membrane #M1 (declined to 80% of its initial value), the AgNPs@ZIF-8 microcapsules-coated membrane #M2 displayed the best anti-biofouling performance with a stabilized phenol mass transfer coefficient of 31.04 × 10–7 m/s (96% of its initial value) after 14-days EMBR testing. Its excellent anti-biofouling property should be attributed to the electrostatic repulsion between membrane surface and microorganisms, antibacterial effects from ZIF-8, improved phenol affinity of the membrane, reduced membrane hydrophobicity, stable released silver ions, broad-spectrum bactericidal properties of the silver ions and reactive oxygen species.

The wound healing property of encapsulated silver nanoparticles made from aqueous extracts of Elaeis guineensis Jacq leaves

A wound can be defined as the disruption of the normal integrity of the body. the management of wounds usually ends up with scars that can cause functional harm and emotional and social distress. All these urge the need for new approaches for faster healing by anti-infective effect, moisturizing, stimulating the healing mechanisms, speeding up the wound closure and dropping scar formation, this paper aimed at evaluating the wound healing effect of cellulose nano encapsulated Elaeis guineensis silver nanoparticle. The plants were collected and formally identified at the national herbarium. After drying and grounding, the aqueous decoction was prepared. The phytochemical screening was performed on the crude extract. From the prepared extracts, the nanoparticle was prepared according to the previously described protocol. The prepared nanoparticles were encapsulated with cellulose. The cellule nanocapsules of Elaeis guineensis were tested for the in vitro anti-inflammatory effect using the heated BSA denaturation test. The acute dermal toxicity of the cellulose nano-encapsulated Elaeis guineesis silver nanoparticle was performed according to guideline 402 of the OEDC. The wound healing test was performed on rat dorsal open wounds using a series of doses of the prepared cellulose nano-encapsulated Elaeis guineesis silver nanoparticle (CNC-EgNP). The extract was revealed to contain alkaloids and polyphenols. Heterosids were not detected. The nanoparticle was successfully prepared, and nano encapsulated with cellulose was successfully done when referring to the absorption feature of the mixture. The results showed that CNC-EgNP protects the protein from heat-denaturation with up to 94.9% with 25µg/ml. Compared to diclofenac, used here as a reference, at 200 µg/ml, the CNC-EgNP seems more effective with 54,2% and 98,65% respectively. No sign of toxicity was observed from the toxicity testing. The CNC-EgNP 200mg/kg BW has the best effect as it annuls the wound after 13 days. CNC-EgNP 100 and 400 mg/kg BW and crude extracts had a statistically similar effect. All annul the wound on day 15. Up to that period, the trolamine, used here as a positive control, failed to bring to 0 the area of the wound. The results highlight the potential of the cellulose nanocapsule of Elaeis guineensis silver nanoparticle as an alternative for wound management.

Enhancement of antibacterial activity through phyto-fabrication of silver nanoparticles with Ficus thonningii aqueous extracts.

The World Health Organisation reports higher levels of bacterial resistance to cephalosporins and carbapenems of above 54%. The sufficient redox capabilities of Ficus thonningii phytochemicals for Ag+ reduction to Ag0 and ultimately aggregation to nucleation are exploited for the first time in attempting to enhance the antibacterial activity. Solution colour change to brown due to surface plasmon resonance phenomenon confirmed nanoparticle fabrication with a UV/Vis absorption peak at 426 nm. Fourier Transform Infrared spectra revealed functional groups (C=C at 1620–1680 cm−1; C=H at 1400–1600 cm−1 aromatics) for encapsulation, stabilisation, and reduction of the silver ion. The Dynamic Light Scattering technique verified F. thonningii encapsulated silver nanoparticles particle size of 57.84 nm with a negative zeta potential (−19.8 mV) as proof of stability. The surface, shape and topographical features were shown by Scanning Electron Microscopy as spherical orientations. An enhanced antimicrobial efficacy was displayed by the nanoparticles (inhibition zones of 26.1, 24.1 and 15.2 mm from 11.5, 10.6 and 6.5 mm) for Staphylococcus aureus, Streptococcus pyrogenes and Escherichia coli, respectively, compared to Flucloxacillin standard that was in the ranges of 21.5, 23.5 and 25.7 mm. The enhanced potency provides a basis for diversified approaches of generating novel drugs for treating bacterial infections.

The antibacterial and biofilm inhibition activity of encapsulated silver nanoparticles in emulsions and its synergistic effect with E. coli bacteriophage

The paper investigates the efficiency of phage-nano combinational therapy in treating planktonic and biofilm bacteria. Silver nanoparticles (AgNPs) were synthesized by olive oil as a coating emulation and characterized. Then, the antibacterial activity, biofilm inhibition, and the compatibility of phage ZCEC5 with AgNPs were evaluated. The results revealed that AgNPs were effective against a wide range of bacteria including Enterobacter spp., Listeria monocytogenes, Klebsiella pneumoniae, Salmonella Enteritidis, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Staphylococcus sciuri, with a minimum inhibitory concentration (MIC) ranging from 0.6 to 3.15% and a minimum bactericidal concentration (MBC) ranged from 3.15 to 12.5%. As a model bacteria, E. coli O157:H7 was tested against the formulated AgNPs alone, and in combination with bacteriophage ZCEC5. While the MIC and MBC for E. coli treated with the AgNPs only were 1.1% and 3.15%, respectively, when combined with phage ZCEC5 (∼108 PFU/mL), the MIC and MBC were reduced to be 0.13% and 0.25%, respectively. Therefore, this paperwork introduces an antibacterial AgNPs against a wide spectrum of Gram-positive and Gram-negative bacteria, along with a novel combinational therapy of AgNPs and bacteriophage.

Synergistic antibacterial and wound-healing applications of an imidazole-based porous organic polymer encapsulated silver nanoparticles composite

Here, a novel antibacterial agent (IM-POP-Ag) through encapsulation of Ag nanoparticles (AgNPs) into an imidazole-based porous organic polymer (IM-POP) was developed for synergistic antibacterial and wound healing. IM-POP with an ultrahigh N content of 38.42 at% was synthesized via the copolymerization of cheap and industrially mass-produced imidazole-2-carbaldehyde and melamine, via catalyst-free Schiff base chemistry, which could realize the effectively anchor of Ag on the porous skeleton (with an Ag loading of 26.01 wt%), avoiding the aggregation and reducing the toxicity of AgNPs greatly. The inherent porosity of POP realizes the effectively control on the size of AgNPs and the coordination of Ag+ changed imidazole into imidazolium, gifting the antibacterial activity to the carriers. As a result, IM-POP-Ag presented a synergistic antibacterial activity against both Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli.). For example, at the same Ag content, the survival rates of E. coli and S. aureus in response to 200 μg mL−1 IM-POP-Ag (equivalent to 50 μg mL−1 AgNPs) were 3.44 ± 0.21% and 6.34 ± 0.40%, respectively, far outperforming that of bare AgNPs (12.19 ± 0.54% and 20.20 ± 0.19%). In vivo experiments on mice testified IM-POP-Ag could significantly promote the healing rate of infected wounds which could facilitate the growth of vessel and hair follicle, accelerating epithelialization. Hence, this novel and mass-produced antibacterial agent provides a new strategy and theoretical basis for the application of AgNPs with higher efficacy and biocompatibility in the near future.

Morphology/Functionality-Tailoring of Arc-Produced Graphite Encapsulated Silver Nanoparticles for Highly Sensitive and Selective Detection of Free Cu2+, Hg2+ and Complex Cr(Iii)-Citrate

Morphology/Functionality-Tailoring of Arc-Produced Graphite Encapsulated Silver Nanoparticles for Highly Sensitive and Selective Detection of Free Cu2+, Hg2+ and Complex Cr(Iii)-Citrate

Polymer Capped Silver Nanoparticles from Ziziphus nummularia Leaves Extract: Potent Antibacterial and Antioxidant Activity

Generally, synthesis and encapsulation process improve therapeutic value of nano encapsulated drugs. The silver nanoparticles (AgNPs) biosynthesized from Ziziphus nummularia leaves and encapsulated with polyvinyl pyrrolidone (PVP) polymer as antibacterial agents, due to its high bioavailability, better encapsulation and less toxic properties. The nanoparticles (AgNPs) biosynthesized from Ziziphus nummularia leaves and capped with polyvinyl pyrrolidone (PVP) polymer, The acquired AgNPs and polymeric functionalized AgNPs were fully characterised by the UV- Visible spectroscopy , Transmission electron microscopy (TEM), X-Ray diffraction pattern (XRD) and Fourier transform infrared spectroscopy (FTIR).The crystalline Ag NPs and Polymer Functionalized AgNPs have a face-centered cubic structure with an average size of 9.20 nm, according to X-ray Diffraction spectroscopy. Fourier Transform Infrared spectroscopy revealed that biomolecules such as proteins are incapable of reducing metal ions and the formation of an encapsulating layer in terms of metal ions. High-Resolution transmission electron microscopy revealed that Polymer functionalized AgNPs ranged in size of 10 nm. AgNPs and Polymer functionalized AgNPs showed effective antimicrobial and antioxidant activity. The biosynthesized monodisperse silver nanoparticles and encapsulated silver nanoparticles demonstrated better antimicrobial and antioxidant activity which can be used in various biomedical applications.

One-step method to prepare core-shell magnetic nanocomposite encapsulating silver nanoparticles with superior catalytic and antibacterial activity

A facile one-step method for synthesis of magnetic core–shell nanocomposite composed of h-Fe3O4 (hollow Fe3O4) core and stable PDA (polydopamine) shell with functional Ag NPs (silver nanoparticles) evenly distributed between them is developed. The h-Fe3O4@Ag/PDA nanocomposite showed excellent catalytic activity in the reaction for reducing azo dyes (methyl orange, methylene blue, and congo red), and the ratios of k values to the weight of h-Fe3O4@Ag/PDA were calculated to be 0.302, 0.0545, and 0.895 min−1 mg−1, respectively. Besides, the h-Fe3O4@Ag/PDA nanocomposite also exhibited good antibacterial activity in the experiment of culturing Bacillus subtilis, and the MIC (minimum inhibitory concentration) was as low as 12.5 μg/mL. Because the Ag NPs will not be leached in the solution under the protection of the PDA shell, the catalytic and antibacterial activities of h-Fe3O4@Ag/PDA nanocomposite could maintain more than 90% after five cycles. Intriguingly, this simple synthetic method can be extended to fabricate different multifunctional nanocomposites such as the spherical SiO2@Ag/PDA and rod-like Fe2O3@Ag/PDA. Overall, the facile fabrication process, the superior catalytic and antibacterial activity, and the excellent stability, endow the h-Fe3O4@Ag/PDA to be a promising nanocomposite.

Cytotoxic and antibacterial activities of starch encapsulated photo-catalyzed phytogenic silver nanoparticles from Paeonia lactiflora flowers

Cytotoxic and antibacterial activities of starch encapsulated photo-catalyzed phytogenic silver nanoparticles from Paeonia lactiflora flowers

Synthesis of PVA Encapsulated Silver Nanoparticles as a Drug Delivery System for Doxorubicin and Curcumin

Synthesis of PVA Encapsulated Silver Nanoparticles as a Drug Delivery System for Doxorubicin and Curcumin

Synthesis of PVA Encapsulated Silver Nanoparticles as a Drug Delivery System for Doxorubicin and Curcumin

Synthesis of PVA Encapsulated Silver Nanoparticles as a Drug Delivery System for Doxorubicin and Curcumin

Synthesis, characterization, and cytotoxicity of starch-encapsulated biogenic silver nanoparticle and its improved anti-bacterial activity

The present work reported synthesis, characterization, and biocompatibility of starch encapsulated silver nanoparticles (St-PF-AgNPs) and their antibacterial activity. The synthesis of St-PF-AgNPs involved in two steps: (i) synthesis of the biogenic silver nanoparticles using the fungal extracts (PF-AgNPs); and, (ii) encapsulation of starch in PF-AgNPs (St-PF-AgNPs). The surface plasmon resonance was found at 420 nm for the PF-AgNPs while it was at 260 and 420 nm for the St-PF-AgNPs. FTIR spectrum demonstrated the capping and encapsulation of the fungal extracts and starch in PF-AgNPs and St-PF-AgNPs. The XRD and TEM-EDS confirmed the crystalline nature, spherical-shaped , and polydispersed- PF-AgNPs and St-PF-AgNPs with strong signals of Ag. The St-PF-AgNPs showed a Z-average size of 115.2 d.nm and zeta potential of −17.8 (mV) as indicated by DLS and zeta potentials. The cytotoxicity results demonstrated higher toxicity of PF-AgNPs than St-PF-AgNPs in HEK293 cells. The antibacterial activity of St-PF-AgNPs were higher than PF-AgNPs in S. aureus. Overall, this work concluded that the starch encapsulation significantly increased the antibacterial activity of PF-AgNPs and this opens a new avenue for the treatment of bacterial infections through the sustained release of PF-AgNPs to target pathogenic bacterial cells.

Antimicrobial Applications of Nanoliposome Encapsulated Silver Nanoparticles: A Potential Strategy to Overcome Bacterial Resistance

Antimicrobial Applications of Nanoliposome Encapsulated Silver Nanoparticles: A Potential Strategy to Overcome Bacterial Resistance