Gold nanoparticles exhibit anti-osteoarthritic effects via modulating interaction of the "microbiota-gut-joint" axis.

Osteoarthritis (OA) is a common degenerative joint disease that can cause severe pain, motor dysfunction, and even disability. A growing body of research indicates that gut microbiota and their associated metabolites are key players in maintaining bone health and in the progression of OA. Short-chain fatty acids (SCFAs) are a series of active metabolites that widely participate in bone homeostasis. Gold nanoparticles (GNPs) with outstanding anti-bacterial and anti-inflammatory properties, have been demonstrated to ameliorate excessive bone loss during the progression of osteoporosis (OP) and rheumatoid arthritis (RA). However, the protective effects of GNPs on OA progression are not clear. Here, we observed that GNPs significantly alleviated anterior cruciate ligament transection (ACLT)-induced OA in a gut microbiota-dependent manner. 16S rDNA gene sequencing showed that GNPs changed gut microbial diversity and structure, which manifested as an increase in the abundance of Akkermansia and Lactobacillus. Additionally, GNPs increased levels of SCFAs (such as butyric acid), which could have improved bone destruction by reducing the inflammatory response. Notably, GNPs modulated the dynamic balance of M1/M2 macrophages, and increased the serum levels of anti-inflammatory cytokines such as IL-10. To sum up, our study indicated that GNPs exhibited anti-osteoarthritis effects via modulating the interaction of "microbiota-gut-joint" axis, which might provide promising therapeutic strategies for OA.

Silver nanoparticle dressing: The knowledge of advantages and limits improves the indications in clinical practice.

Silver nanoparticle dressings have gained popularity recently as a way to treat challenging wounds. Notwithstanding the properties of Ag-NPS (silver nanoparticles) described by several articles, there is a lack of clinical studies that guide healthcare professionals to specific and conscious use. In this case series, Ag-NPS dressing was tested on a randomized group of 10 patients with complex wounds requiring conservative treatment. Each case was analysed, recording the patient's history, the peculiar characteristics and the progressive changes in the wound. The wound bed and the quality of the peri-wound skin improved and a decrease in signs of infection was observed. The application of the dressing was simple and comfortable for the patient and it was appreciated for its sealing ability. A few capacity restrictions showed up: those should be read as elements to improve the indications for this peculiar dressing. The thin tissue matrix of the Ag-NPS dressing does not allow for massive absorption and also performs poorly in reducing little exudate. The reduction in wound width is also limited: reconstructive surgery was required in half of the enrolled patients to achieve wound healing.

Green Synthesis of Metal-Doped ZnO Nanoparticles Using Bauhinia racemosa Lam. Extract and Evaluation of Their Photocatalysis and Biomedical Applications.

A fascinating problem in the fields of nanoscience and nanobiotechnology has recently emerged, and to tackle this, the production of metal oxide nanoparticles using plant extracts offers numerous benefits over traditional physicochemical methods. In the present investigation, ZnO nanoparticles were fabricated from Bauhinia racemosa Lam. (BR) leaves extract with various transition metal (TM) dopants (Ni, Mn, and Co). Plant leaves extract containing metal nitrate solutions were utilized as a precursor to synthesize the pristine and TM-doped ZnO nanoparticles. Structural, functional, optical, and surface properties of the fabricated samples were studied by using physicochemical and photoelectrochemical measurements. The organic pollutants tetracycline (TC), ampicillin (AMP), and amoxicillin (AMX) were used in the photocatalytic degradation assessment of the fabricated samples. Through X-ray diffraction (XRD) and transmission electron microscopy (TEM) investigation, the fabricated nanoparticles wurtzite crystal structure was verified. Moreover, Fourier transform infrared (FT-IR) analysis verified the existence of functional groups in the fabricated nanoparticles. The migration of electrons from the deep donor level and zinc interstitial to the Zn-defect and O-defect is related to the emission peaks seen at 468, 480, 534, and 450 nm in photoluminescence (PL) spectra. Co-ZnO nanoparticles demonstrated potent and excellent photocatalytic degradation performance for TC (91.09%), AMP (87.97%), and AMX (92.42%) antibiotics within 210, 180, and 150 min of visible light irradiation. Co-ZnO nanoparticles also demonstrated strong antimicrobial performance against Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, Aspergillus flavus, Aspergillus niger, and Bacillus subtilis. Further investigation of in vitro cytotoxic potential against the A549 cell line (IC50 = 24 ± 0.5 µg/mL) utilizing MTT assay and the free radical scavenging performance of Co-ZnO nanoparticles estimated by DPPH assay utilizing l-ascorbic acid as a reference was also performed. Anti-inflammatory potential is also reviewed by comparing it with the standard drug Diclofenac, and the maximum activity was obtained for Ni-ZnO nanoparticles (IC50 = 72.4 µg/mL).

Unravelling the Antimicrobial, Antibiofilm, Suppressing Fibronectin Binding Protein A (fnba) and cna Virulence Genes, Anti-Inflammatory and Antioxidant Potential of Biosynthesized Solanum lycopersicum Silver Nanoparticles.

Background and Objectives: Urinary tract infections [UTIs] are considered the third most known risk of infection in human health around the world. There is increasing appreciation for the pathogenicity of Gram-positive and Gram-negative strains in UTIs, aside from fungal infection, as they have numerous virulence factors. Materials and Methods: In this study, fifty urine samples were collected from patients suffering from UTI. Among the isolates of UTI microbes, six isolates were described as MDR isolates after an antibiotic susceptibility test carried out using ten different antibiotics. An alternative treatment for microbial elimination involved the use of biosynthesized silver nanoparticles (AgNPs) derived from Solanum lycopersicum [S. cumin]. Results: The sizes and shapes of AgNPs were characterized through TEM imaging, which showed spherical particles in a size range of 35-80 nm, of which the average size was 53 nm. Additionally, the silver nanoparticles (AgNPs) demonstrated inhibitory activity against Staphylococcus aureus (OR648079), exhibiting a 31 mm zone of inhibition at a minimum inhibitory concentration (MIC) of 4 mg/mL and a minimum bactericidal concentration (MBC) of 8 mg/mL. This was followed by Aspergillus niger (OR648075), which showed a 30 mm inhibition zone at an MIC of 16 mg/mL and a minimum fungicidal concentration (MFC) of 32 mg/mL. Then, Enterococcus faecalis (OR648078), Klebsiella pneumoniae (OR648081), and Acinetobacter baumannii (OR648080) each displayed a 29 mm zone of inhibition at an MIC of 8 mg/mL and an MBC of 16 mg/mL. The least inhibition was observed against Candida auris (OR648076), with a 25 mm inhibition zone at an MIC of 16 mg/mL and an MFC of 32 mg/mL. Furthermore, AgNPs at different concentrations removed DPPH and H2O2 at an IC50 value of 13.54 µg/mL. Also, AgNPs at 3 mg/mL showed remarkable DNA fragmentation in all bacterial strains except Enterococcus faecalis. The phytochemical analysis showed the presence of different active organic components in the plant extract, which concluded that rutin was 88.3 mg/g, garlic acid was 70.4 mg/g, and tannic acid was 23.7 mg/g. Finally, AgNPs concentrations in the range of 3-6 mg/mL showed decreased expression of two of the fundamental genes necessary for biofilm formation within Staphylococcus aureus, fnbA (6 folds), and Cna (12.5 folds) when compared with the RecA gene, which decreased by one-fold when compared with the control sample. These two genes were submitted with NCBI accession numbers [OR682119] and [OR682118], respectively. Conclusions: The findings from this study indicate that biosynthesized AgNPs from Solanum lycopersicum exhibit promising antimicrobial and antioxidant properties against UTI pathogens, including strains resistant to multiple antibiotics. This suggests their potential as an effective alternative treatment for UTIs. Further research is warranted to fully understand the mechanisms of action and to explore the therapeutic applications of these nanoparticles in combating UTIs.

Gold nanoparticles-mediated photothermal and photodynamic therapies for cancer.

Cancer remains one of the major causes of death globally, with one out of every six deaths attributed to the disease. The impact of cancer is felt on psychological, physical, and financial levels, affecting individuals, communities, and healthcare institutions. Conventional cancer treatments have many challenges and inadequacies. Nanomedicine, however, presents a promising solution by not only overcoming these problems but also offering the advantage of combined therapy for treatment-resistant cancers. Nanoparticles specifically engineered for use in nanomedicine can be efficiently targeted to cancer cells through a combination of active and passive techniques, leading to superior tumor-specific accumulation, enhanced drug availability, and reduced systemic toxicity. Among various nanoparticle formulations designed for cancer treatment, gold nanoparticles have gained prominence in the field of nanomedicine due to their photothermal, photodynamic, and immunologic effects without the need for photosensitizers or immunotherapeutic agents. To date, there is no comprehensive literature review that focuses on the photothermal, photodynamic, and immunologic effects of gold nanoparticles. In this review, significant attention has been devoted to examining the parameters pertaining to the structure of gold nanoparticles and laser characteristics, which play a crucial role in influencing the efficacy of photothermal therapy (PTT) and photodynamic therapy (PDT). Moreover, this article provides insights into the success of PTT and PDT mediated by gold nanoparticles in primary cancer treatment, as well as the immunological effects of PTT and PDT on metastasis and recurrence, providing a promising strategy for cancer therapy. In summary, gold nanoparticles, with their unique properties, have the potential for clinical application in various cancer therapies, including the treatment of primary cancer, recurrence and metastasis.

Bionic nanotheranostic for multimodal imaging-guided NIR-II-photothermal cancer therapy.

In photothermal therapy (PTT), the photothermal conversion of the second near-infrared (NIR-II) window allows deeper penetration and higher laser irradiance and is considered a promising therapeutic strategy for deep tissues. Since cancer remains a leading cause of deaths worldwide, despite the numerous treatment options, we aimed to develop an improved bionic nanotheranostic for combined imaging and photothermal cancer therapy. We combined a gold nanobipyramid (Au NBP) as a photothermal agent and MnO2 as a magnetic resonance enhancer to produce core/shell structures (Au@MnO2; AM) and modified their surfaces with homologous cancer cell plasma membranes (PM) to enable tumour targeting. The performance of the resulting Au@MnO2@PM (AMP) nanotheranostic was evaluated in vitro and in vivo. AMP exhibits photothermal properties under NIR-II laser irradiation and has multimodal in vitro imaging functions. AMP enables the computed tomography (CT), photothermal imaging (PTI), and magnetic resonance imaging (MRI) of tumours. In particular, AMP exhibited a remarkable PTT effect on cancer cells in vitro and inhibited tumour cell growth under 1064 nm laser irradiation in vivo, with no significant systemic toxicity. This study achieved tumour therapy guided by multimodal imaging, thereby demonstrating a novel strategy for the use of bionic gold nanoparticles for tumour PTT under NIR-II laser irradiation.

Multifunctional Metal-Phenolic Composites Promote Efficient Periodontitis Treatment via Antibacterial and Osteogenic Properties.

Periodontitis, a complex inflammatory disease initiated by bacterial infections, presents a significant challenge in public health. The increased levels of reactive oxygen species and the subsequent exaggerated immune response associated with periodontitis often lead to alveolar bone resorption and tooth loss. Herein, we develop multifunctional metal-phenolic composites (i.e., Au@MPN-BMP2) to address the complex nature of periodontitis, where gold nanoparticles (AuNPs) are coated by metal-phenolic networks (MPNs) and bone morphogenetic protein 2 (BMP2). In this design, MPNs exhibit remarkable antibacterial and antioxidant properties, and AuNPs and BMP2 promote osteogenic differentiation of bone marrow mesenchymal stem cells under inflammatory conditions. In a rat model of periodontitis, treatment with Au@MPN-BMP2 leads to notable therapeutic outcomes, including mitigated oxidative stress, reduced progression of inflammation, and the significant prevention of inflammatory bone loss. These results highlight the multifunctionality of Au@MPN-BMP2 nanoparticles as a promising therapeutic approach for periodontitis, addressing both microbial causative factors and an overactivated immune response. We envision that the rational design of metal-phenolic composites will provide versatile nanoplatforms for tissue regeneration and potential clinical applications.

Improved Immune Response for Colorectal Cancer Therapy Triggered by Multifunctional Nanocomposites with Self-Amplifying Antitumor Ferroptosis.

Ferroptosis, as a type of regulated cell death, can trigger the release of damage-associated molecular patterns from cancer cells and lead to the enhancement of immune recognition. Fenton reaction-mediated chemodynamic therapy could initiate ferroptosis by generating lipid peroxides, but its efficiency would be greatly restricted by the insufficient H2O2 and antioxidant system within the tumor. Herein, this work reports the successful preparation of H2O2 self-supplied and glutathione (GSH)-depletion therapeutic nanocomposites (Cu2O@Au) through in situ growth of Au nanoparticles on the surface of cuprous oxide (Cu2O) nanospheres. Upon delivery into cancer cells, the released Cu2O could consume endogenous H2S within colorectal cancer cells to form Cu31S16 nanoparticles, while the released Au NPs could catalyze glucose to generate H2O2 and gluconic acid. The self-supplying endogenous H2O2 and lower acidity could amplify the Cu ion-induced Fenton-like reaction. Meanwhile, the consumption of glucose would reduce GSH generation by disrupting the pentose phosphate pathway. Additionally, the Cu2+/Cu+ catalytic cycle promotes the depletion of GSH, leading to lipid peroxide accumulation and ferroptosis. It was found that the onset of ferroptosis triggered by Cu2O@Au could initiate immunologic cell death, promote dendritic cell maturation and T-cell infiltration, and finally enhance the antitumor efficacy of the PD-L1 antibody. In summary, this collaborative action produces a remarkable antitumor effect, which provides a promising treatment strategy for colorectal cancer.

Targeting EGFR and VEGFR-2 Kinases With Nanoparticles: A Computational Approach for Cancer Therapy Advancement.

The study investigates titanium and zinc nanoparticles as inhibitors for the epidermal growth factor receptor (EGFR) and vascular endothelial growth factor receptor-2 (VEGFR-2), pivotal regulators of cell processes. VEGFR-2 activation fuels tumor angiogenesis in cancer cells, sustaining malignant tissue expansion. Molecular docking analysis illustrates the nanoparticles' binding to the active sites, inhibiting the phosphorylation of key proteins in downstream signaling. This inhibition offers a promising therapeutic approach to impede cancer-related signaling, potentially slowing down aberrant protein cascades controlled by EGFR and VEGFR-2. The findings propose a novel avenue for cancer treatment, targeting abnormal growth pathways using titanium and zinc nanoparticles.

Characterizations of Centrifugal Electrospun Polyvinyl Alcohol/Sodium Alginate/Tamanu Oil/Silver Nanoparticles Wound Dressing.

Known for its water solubility, flexibility, strong adhesion, and eco-friendly nature, polyvinyl alcohol (PVA) is widely used in various industries. In the medical field, it is used for applications such as creating bandages and orthopaedic devices. Incorporating sodium alginate (SA) into PVA membranes enhances their structural integrity, breathability, and permeability, thereby minimising the risk of cellular damage in the wound zone. Moreover, the addition of tamanu oil (C alophyllum inophyllum L.) and silver nanoparticles, both of which are known for their antibacterial properties and benefits in traditional wound healing, further enhances the membranes' wound-healing effectiveness. Following production, the membranes undergo a series of tests designed to evaluate their physical properties as well as their antioxidant and antibacterial capabilities. Subsequently, in vitro testing is conducted using human skin cells; experiments on Wistar rats are then performed. Numerous experiments have consistently demonstrated that the performance of polyvinyl alcohol/sodium alginate/tamanu oil (PVA/SA/Oil) membrane is superior to that of polyvinyl alcohol/sodium alginate/tamanu oil/silver nanoparticles (PVA/SA/Oil/Ag NP) membrane. Specifically, the polyvinyl alcohol/sodium alginate (PVA/SA) combination exhibits an impressive wound-healing rate of 98.82% after 15 days, with cells maintaining a high viability of 92% in a nourishing environment. Moreover, these membranes exhibit exceptional resistance to the oxidation of free radicals, surpassing the 70% threshold, and they possess antibacterial activity against Staphylococcus aureus subsp. aureus in vitro. Based on the obtained results, the nanofiber membranes composed of polyvinyl alcohol/ alginate/ tamanu oil, with or without silver nanoparticles, have shown potential as wound dressings in the wound care discipline.

Mentha piperita silver nanoparticle-loaded hydrocolloid film for enhanced diabetic wound healing in rats.

OBJECTIVE: To investigate the role of Mentha piperita silver nanoparticle-loaded carbopol gel for enhanced wound healing in a diabetic rat model. This research further aims to explore bioactive compounds derived from Mentha piperita obtained from high altitude. METHOD: Methanolic extracts of Mentha piperita (MP), Mentha spicata (MS) and Mentha longifolia (ML) were used to synthesise silver nanoparticles (AgNP). AgNP synthesis was confirmed by ultraviolet-visible (UV-Vis) spectroscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The antioxidant activity was assessed by 2, 2-diphenyl-1-picrylhydrazyl (DDPH) assay. Antiglycation potential was determined by measuring the fluorescent advanced glycation end products. The bioactive compound identified in the Mentha piperita methanolic (MPM) fraction through electrospray ionisation tandem mass spectrometric analysis (ESI-MS) was responsible for the highest antiglycation. The effects of MPM and MPM.AgNP-loaded Carbopol (Sanare Lab, India) on wound healing were compared in male, alloxan-induced, diabetic albino rats (200-250g), divided into control and treated groups. Effects on wound healing were assessed via histopathology. RESULTS: UV-Vis and FTIR confirmed NP synthesis with peaks for flavonoids and polyphenols. SEM and XRD explored the cubical, 30-63nm crystalline NP. The maximum antioxidant and antiglycation potential was observed in order of; MP.AgNP>MS.AgNP>ML.AgNP. The highest antioxidant activity was observed by methanolic and aqueous MP.AgNPs (88.55% and 83.63%, respectively) at 2mg.ml-1, and (75.16% and 69.73%, respectively) at 1mg.ml-1, compared to ascorbic acid (acting as a positive control, 90.01%). MPM.AgNPs demonstrated the best antiglycation potential of 75.2% and 83.3% at 1mg.ml-1 and 2mg.ml-1, respectively, comparable to positive control (rutin: 88.1%) at 14 days post-incubation. A similar trend was observed for antimicrobial activity against Bacillus subtilis, Micrococcus luteus and Escherichia coli with an inhibition zone of 21mm, 21.6mm and 24.6mm. Rosmarinic acid was the active compound present in Mentha piperita, as identified by ESI-MS. MPM.AgNP-loaded Carbopol resulted in 100% wound closure compared with control at 20 days post-wounding. In the treatment group, re-epithelialisation was achieved by day 18, compared with 25 days for the positive control group. CONCLUSION: MPM.AgNP-loaded Carbopol demonstrated safer and more effective biological properties, hence accelerating the diabetic excision wound healing process in alloxan-induced diabetic rats.

Multifunctional Inorganic-Organic Composite Carriers for Synergistic Dual Therapy of Melanoma.

Many methods for cancer treatment have been developed. Among them photothermal therapy (PTT) has drawn the most significant attention due to its noninvasiveness, remote control activation, and low side effects. However, a limited depth of light penetration of PTT is the main drawback. To improve the therapeutic efficiency, the development of combined PTT with other therapeutic agents is highly desirable. In this work, we have designed multifunctional composite carriers based on polylactic acid (PLA) particles decorated with gold nanorods (Au NRs) as nanoheaters and selenium nanoparticles (Se NPs) for reactive oxygen species (ROS) production in order to perform a combined PTT against B16-F10 melanoma. To do this, we have optimized the synthesis of PLA particles modified with Se NPs and Au NRs (PLA-Se:Au), studied the cellular interactions of PLA particles with B16-F10 cells, and analyzed in vivo biodistribution and tumor inhibition efficiency. The results of in vitro and in vivo experiments demonstrated the synergistic effect from ROS induced by Se NPs and the heating from Au NRs. In melanoma tumor-bearing mice, intratumoral injection of PLA-Se:Au followed by laser irradiation leads to almost complete elimination of tumor tissues. Thus, the optimal photothermal properties and ROS-generating capacity allow us to recommend PLA-Se:Au as a promising candidate for the development of the combined PTT against melanoma.

Near-infrared laser-assisted Ag@Chi-PB nanocompounds for synergistically eradicating multidrug-resistant bacteria and promoting diabetic abscess healing.

Chronic wound infections, particularly multidrug-resistant microbe-caused infections, have imposed severe challenges in clinical administration. The therapeutic effectiveness of the current strategy using conventional antibiotics is extremely unsatisfactory. The development of novel treatment strategies to inhibit the infections caused by multidrug-resistant bacteria is highly desired. In this work, based on the combination of nanocompounds with the assistance of NIR laser, an antibacterial strategy was designed for MRSA-infected abscesses in diabetic mice. The nanocompounds named Ag@Chi-PB were prepared by using chitosan-coated Prussian blue (PB) as a nanocarrier for silver nanoparticles anchoring. Combined with near-infrared (NIR) laser, the nanocompounds were more efficient at killing Escherichia coli (E. coli) and Methicillin-resistant staphyllococcus aureus (MRSA) in vitro. Notably, MRSA was significantly removed in vivo and promoted diabetic abscess healing by the combined therapy of this nanocompound and NIR laser, owing to the synergistic antibacterial effect of photothermal therapy and release of Ag+. Meanwhile, the nanocompound showed satisfactory biocompatibility and superior biosafety. Collectively, the combination therapy of this nanocompound with the assistance of NIR laser may represent a promising strategy for clinical anti-infection.

Gold nanoparticles decorated on MOF derived Cu5Zn8 hollow porous carbon nanocubes for magnetic resonance imaging guided tumor microenvironment-mediated synergistic chemodynamic and photothermal therapy.

Combining chemodynamic therapy (CDT) with photothermal therapy (PTT) has developed as a promising approach for cancer treatment, as it enhances therapeutic efficiency through redox reactions and external laser induction. In this study, we designed metal organic framework (MOF) -derived Cu5Zn8/HPCNC through a carbonization process and decorated them with gold nanoparticles (Au@Cu5Zn8/HPCNC). The resulting nanoparticles were employed as a photothermal agent and Fenton catalyst. The Fenton reaction facilitated the conversation of Cu2+ to Cu+ through reaction with local H2O2, generating reactive hydroxyl radicals (·OH) with potent cytotoxic effects. To enhance the Fenton-like reaction and achieve combined therapy, laser irradiation of the Au@Cu5Zn8/HPCNC induced efficient photothermal therapy by generating localized heat. With a significantly increased absorption of Au@Cu5Zn8/HPCNC at 808 nm, the photothermal efficiency was determined to be 57.45 %. Additionally, Au@Cu5Zn8/HPCNC demonstrated potential as a contrast agent for magnetic resonance imaging (MRI) of cancers. Furthermore, the synergistic combination of PTT and CDT significantly inhibited tumor growth. This integrated approach of PTT and CDT holds great promise for cancer therapy, offering enhanced CDT and modulation of the tumor microenvironment (TME), and opening new avenues in the fight against cancer.

Bioorthogonal "Click and Release" Reaction-Triggered Aggregation of Gold Nanoparticles Combined with Released Lonidamine for Enhanced Cancer Photothermal Therapy.

Cancer has been the most deadly disease, and 13 million cancer casualties are estimated to occur each year by 2030. Gold nanoparticles (AuNPs)-based photothermal therapy (PTT) has attracted great interest due to its high spatiotemporal controllability and noninvasiveness. Due to the trade-off between particle size and photothermal efficiency of AuNPs, rational design is needed to realize aggregation of AuNPs into larger particles with desirable NIR adsorption in tumor site. Exploiting the bioorthogonal "Click and Release" (BCR) reaction between iminosydnone and cycloalkyne, aggregation of AuNPs can be achieved and attractively accompanied by the release of chemotherapeutic drug purposed to photothermal synergizing. We synthesize iminosydnone-lonidamine (ImLND) as a prodrug and choose dibenzocyclooctyne (DBCO) as the trigger of BCR reaction. A PEGylated AuNPs-based two-component nanoplatform consisting of prodrug-loaded AuNPs-ImLND and tumor-targeting peptide RGD-conjugated AuNPs-DBCO-RGD is designed. In the therapeutic regimen, AuNPs-DBCO-RGD are intravenously injected first for tumor-specific enrichment and retention. Once the arrival of AuNPs-ImLND injected later at tumor site, highly photothermally active nanoaggregates of AuNPs are formed via the BCR reaction between ImLND and DBCO. The simultaneous release of lonidamine further enhanced the therapeutic performance by sensitizing cancer cells to PTT.

Metallic nanoparticles and treatment of cutaneous leishmaniasis: A systematic review.

BACKGROUND: Cutaneous leishmaniasis (LC) is an infectious vector-borne disease caused by parasites belonging to the genus Leishmania. Metallic nanoparticles (MNPs) have been investigated as alternatives for the treatment of LC owing to their small size and high surface area. Here, we aimed to evaluate the effect of MNPs in the treatment of LC through experimental, in vitro and in vivo investigations. METHODS: The databases used were MEDLINE/ PubMed, Scopus, Web of Science, Embase, and Science Direct. Manual searches of the reference lists of the included studies and grey literature were also performed. English language and experimental in vitro and in vivo studies using different Leishmania species, both related to MNP treatment, were included. This study was registered in PROSPERO (CRD42021248245). RESULTS: A total of 93 articles were included. Silver nanoparticles are the most studied MNPs, and L. tropica is the most studied species. Among the mechanisms of action of MNPs in vitro, we highlight the production of reactive oxygen species, direct contact of MNPs with the biomolecules of the parasite, and release of metal ions. CONCLUSION: MNPs may be considered a promising alternative for the treatment of LC, but further studies are needed to define their efficacy and safety.

Nanofibers of N,N,N-trimethyl chitosan capped bimetallic nanoparticles: Preparation, characterization, wound dressing and in vivo treatment of MDR microbial infection and tracking by optical and photoacoustic imaging.

Recent advancements in wound care have led to the development of interactive wound dressings utilizing nanotechnology, aimed at enhancing healing and combating bacterial infections while adhering to established protocols. Our novel wound dressings consist of N,N,N-trimethyl chitosan capped gold­silver nanoparticles (Au-Ag-TMC-NPs), with a mean size of 108.3 ± 8.4 nm and a zeta potential of +54.4 ± 1.8 mV. These optimized nanoparticles exhibit potent antibacterial and antifungal properties, with minimum inhibitory concentrations ranging from 0.390 µg ml-1 to 3.125 µg ml-1 and also exhibited promising zones of inhibition against multi-drug resistant strains of S. aureus, E. coli, P. aeruginosa, and C. albicans. Microbial transmission electron microscopy reveals substantial damage to cell walls and DNA condensation post-treatment. Furthermore, the nanoparticles demonstrate remarkable inhibition of microbial efflux pumps and are non-hemolytic in human blood. Incorporated into polyvinyl alcohol/chitosan nanofibers, they form Au-Ag-TMC-NPs-NFs with diameters of 100-350 nm, facilitating efficient antimicrobial wound dressing. In vivo studies on MDR microbial-infected wounds in mice showed 99.34 % wound healing rate within 12 days, corroborated by analyses of wound marker protein expression levels and advanced imaging techniques such as ultrasound/photoacoustic imaging, providing real-time visualization and blood flow assessment for a comprehensive understanding of the dynamic wound healing processes.

Recent updates and feasibility of nanodrugs in the prevention and eradication of dental biofilm and its associated pathogens-A review.

OBJECTIVES: Dental biofilm is one of the most prevalent diseases in humans, which is mediated by multiple microorganisms. Globally, half of the human population suffers from dental biofilm and its associated diseases. In recent trends, nano-formulated drugs are highly attractive in the treatment of dental biofilms. However, the impact of different types of nanodrugs on the dental biofilm and its associated pathogens have not been published till date. Thus, this review focuses on the recent updates, feasibility, mechanisms, limitations, and regulations of nanodrugs applications in the prevention and eradication of dental biofilm. STUDY SELECTION, DATA AND SOURCES: A systematic search was conducted in PubMed/Google Scholar/Scopus over the past five years covering the major keywords "nanodrugs, metallic nanoparticles, metal oxide nanoparticles, natural polymers, synthetic polymers, biomaterials, dental biofilm, antibiofilm mechanism, dental pathogens", are reviewed in this study. Nearly, 100 scientific articles are selected in this relevant topic published between 2019 and 2023. Data from the selected studies dealing with nanodrugs used for biofilm treatment was qualitatively analyzed. CONCLUSIONS: The nanodrugs such as silver nanoparticles, gold nanoparticles, selenium nanoparticles, zinc oxide nanoparticles, copper oxide nanoparticles, titanium oxide nanoparticles, hydroxyapatite nanoparticles and these inorganic nanoparticles incorporated polymer-based nanocomposites, organic/inorganic nanoparticles mediated antimicrobial photodynamic therapy exhibits an excellent antibacterial and antibiofilm activity towards dental pathogens. Finally, this review highlights that bioinspired nanodrugs will be very useful to control the dental biofilm and its associated diseases. CLINICAL SIGNIFICANCE: Microbial influence on the oral environment is unavoidable; therefore, curing such dental biofilms and pathogens is essential for the impactful reflection of applying biocompatible treatments. In this direction, the current review explains the demand for the nanodrug in inhibiting biofilms for the effective exploration of employing treatments.

Gold nanobipyramids-based laser-activated sealants for effective skin sealing and repair.

Anisotropic gold nanostructures have gained increased attention for biomedical applications because of their remarkable optical properties. An emerging type of gold nanostructure-gold nanobipyramids (AuNBP)-has been shown to exhibit superior absorption properties compared to conventionally used gold nanoparticles, which makes them attractive for photothermal applications. We generated a high-shape-purity dispersion of AuNBP using a seed-mediated method and embedded them as photothermal conversion agents in a silk fibroin matrix to investigate their efficacy in photothermal sealing of incisional wounds in immunocompetent mice. These AuNBP-doped laser-activated sealants, or AuNBP-LASE were able to absorb near-infrared laser energy and convert it to heat, thereby inducing transient hyperthermia in the wound and the surrounding tissue. This photothermal conversion facilitated rapid sealing of the skin tissue by the AuNBP-LASE, which resulted in faster functional recovery of skin barrier function compared to nylon sutures at the early stages of repair. Further, the biomechanical properties of the healing skin closed with AuNBP-LASE those of intact skin more rapidly compared to incisions approximated with sutures. Histology studies indicated higher penetration of the LASE within the volume of the incision in skin tissue, lower scab formation, and a similar epidermal gap compared to conventional suturing. These results demonstrate that AuNBP-LASEs can be effective as wound approximation devices for photothermal sealing.

Activity of biogenic silver nanoparticles in planktonic and biofilm-associated Corynebacterium pseudotuberculosis.

Corynebacterium pseudotuberculosis is a gram-positive bacterium and is the etiologic agent of caseous lymphadenitis (CL) in small ruminants. This disease is characterized by the development of encapsulated granulomas in visceral and superficial lymph nodes, and its clinical treatment is refractory to antibiotic therapy. An important virulence factor of the Corynebacterium genus is the ability to produce biofilm; however, little is known about the characteristics of the biofilm produced by C. pseudotuberculosis and its resistance to antimicrobials. Silver nanoparticles (AgNPs) are considered as promising antimicrobial agents, and are known to have several advantages, such as a broad-spectrum activity, low resistance induction potential, and antibiofilm activity. Therefore, we evaluate herein the activity of AgNPs in C. pseudotuberculosis, through the determination of minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), antibiofilm activity, and visualization of AgNP-treated and AgNP-untreated biofilm through scanning electron microscopy. The AgNPs were able to completely inhibit bacterial growth and inactivate C. pseudotuberculosis at concentrations ranging from 0.08 to 0.312 mg/mL. The AgNPs reduced the formation of biofilm in reference strains and clinical isolates of C. pseudotuberculosis, with interference values greater than 80% at a concentration of 4 mg/mL, controlling the change between the planktonic and biofilm-associated forms, and preventing fixation and colonization. Scanning electron microscopy images showed a significant disruptive activity of AgNP on the consolidated biofilms. The results of this study demonstrate the potential of AgNPs as an effective therapeutic agent against CL.