Silver Mesoporous Silica Nanoparticles: Fabrication to Combination Therapies for Cancer and Infection

Enrofloxacin‑silver composite nano-emulsion as a scalable synergetic antibacterial platform for accelerating infected wound healing

The colonization of bacterial pathogens is a major concern in wound infection and becoming a notable medical issue. Enrofloxacin (ENR) can be applied to treat skin infections, while poor water solubility and bioavailability limit its clinical application. Nanostructured lipid carriers (NLCs) enhance the solubility and bioavailability of drugs by encapsulating them, making them effective for the topical treatment of skin wound infections. Additionally, to enhance treatment efficacy and further improve wound healing, silver nanoparticles (AgNPs) were attached to the aforementioned matrix, which also improved its colloidal stability and reduced toxicity. Herein, a scalable poly (vinyl alcohol) modified NLCs-based antibacterial platform was fabricated by high-pressure homogenization method, to co-load ENR and AgNPs for treating the bacterial-infected wounds. The growth of common wound bacterial pathogens (Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa) was synergistically inhibited by released ENR and Ag+ from the poly (vinyl alcohol) modified enrofloxacin‑silver composite nano-emulsion (ENR@PVA-NLCs/AgNPs). In the in vivo wound model, the Staphylococcus aureus-infected wound in rat almost completely disappeared after treatment with ENR@PVA-NLCs/AgNPs, and no suppuration symptom was observed. Importantly, this nanoplatform had negligible side effects in vivo. Taken together, the above results strongly demonstrate the promising potential of ENR@PVA-NLCs/AgNPs as a synergistic therapeutic agent for clinical wound infections.

Recent advances in nanomaterials and their mechanisms for infected wounds management

Wounds infected by bacteria pose a considerable challenge in the field of healthcare, particularly with the increasing prevalence of antibiotic-resistant pathogens. Traditional antibiotics often fail to achieve effective results due to limited penetration, resistance development, and inadequate local concentration at wound sites. These limitations necessitate the exploration of alternative strategies that can overcome the drawbacks of conventional therapies. Nanomaterials have emerged as a promising solution for tackling bacterial infections and facilitating wound healing, thanks to their distinct physicochemical characteristics and multifunctional capabilities. This review highlights the latest developments in nanomaterials that demonstrated enhanced antibacterial efficacy and improved wound healing outcomes. The antibacterial mechanisms of nanomaterials are varied, including ion release, chemodynamic therapy, photothermal/photodynamic therapy, electrostatic interactions, and delivery of antibacterial drugs, which not only combat bacterial infections but also address the challenges posed by biofilms and antibiotic resistance. Furthermore, these nanomaterials create an optimal environment for tissue regeneration, promoting faster wound closure. By leveraging the unique attributes of nanomaterials, there is a significant opportunity to revolutionize the management of infected wounds and markedly improve patient outcomes.

Silver immobilized magnetic iron nanoparticles fabricated via green method for detection of cobalt in water and their antibacterial activity

This study reports the eco-friendly synthesis of silver immobilized magnetic iron nanoparticles (MAgNPs) using Zingiber officinale (ginger) peel extract, which serves as a reducing and stabilizing agent. Employing a green synthesis approach, these nanoparticles are fabricated to address environmental and health-related applications. The synthesized MAgNPs demonstrated significant performance in detecting cobalt (Co2+) ion in water, with a detection limit reaching as low as 10-9M. Moreover, the antibacterial activity tests against E. coli and S. aureus exhibited substantial inhibition zones measuring up to 18.8 mm for MAgNPs at a concentration of 125 µg/mL. Structural and physicochemical characterizations were carried out using techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), Energy dispersive X-ray, UV-vis spectroscopy, Fourier-transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA), which confirmed the successful coating of silver on magnetic nanoparticles. The BET analysis revealed a specific surface area of 99.304 m2/g, indicating a high potential for adsorptive applications. This work not only highlights the use of natural waste in nanotechnology but also contributes to the development of nanomaterials with promising applications in the environmental and healthcare sectors, thereby supporting sustainable material development.

Conductive Superhydrophobic Smart Coatings Based on Spherical Silver Nanoparticles and Waterborne Polyurethane for Flexible and Wearable Electronics

The development of flexible smart conductive fabrics is crucial for applications in smart healthcare and signal transmission during hazardous rescue operations. However, environmental challenges such as moisture, dirt, mechanical abrasion, and bacteria can significantly impair their electronic performance. Herein, we introduce a novel two-layered coating strategy that integrates silver nanoparticles (Ag NPs) and modified silica nanoparticles (QSi) with waterborne polyurethane (WPU) to develop multifunctional superhydrophobic conductive coatings. The inner composite layer, combining WPU with Ag NPs, guarantees high conductivity (5.22 S·cm-1) and mechanical durability. The outer shell layer, created by spraying a mixture of WPU and QSi, provides a robust superhydrophobic barrier, maintaining a water contact angle above 150° and resistance below 80 Ω even after 200 kneading cycles. Additionally, the coated fabric exhibits satisfactory self-cleaning, antifouling, low water adhesion (32.95 μN), drag reduction (supporting approximately 11 times its weight on water), and appreciable antibacterial activity (>99.99%), ensuring its long-term stability in harsh conditions. By integrating conductivity with superhydrophobicity, flexibility, and wearability, this smart fabric presents a promising strategy for precise underwater detection, such as monitoring swimming movements or finger bending, while also offering safety alert signals in challenging wet environments.

Nanomaterials: leading immunogenic cell death-based cancer therapies

The field of oncology has transformed in recent years, with treatments shifting from traditional surgical resection and radiation therapy to more diverse and customized approaches, one of which is immunotherapy. ICD (immunogenic cell death) belongs to a class of regulatory cell death modalities that reactivate the immune response by facilitating the interaction between apoptotic cells and immune cells and releasing specific signaling molecules, and DAMPs (damage-associated molecular patterns). The inducers of ICD can elevate the expression of specific proteins to optimize the TME (tumor microenvironment). The use of nanotechnology has shown its unique potential. Nanomaterials, due to their tunability, targeting, and biocompatibility, have become powerful tools for drug delivery, immunomodulators, etc., and have shown significant efficacy in clinical trials. In particular, these nanomaterials can effectively activate the ICD, trigger a potent anti-tumor immune response, and maintain long-term tumor suppression. Different types of nanomaterials, such as biological cell membrane-modified nanoparticles, self-assembled nanostructures, metallic nanoparticles, mesoporous materials, and hydrogels, play their respective roles in ICD induction due to their unique structures and mechanisms of action. Therefore, this review will explore the latest advances in the application of these common nanomaterials in tumor ICD induction and discuss how they can provide new strategies and tools for cancer therapy. By gaining a deeper understanding of the mechanism of action of these nanomaterials, researchers can develop more precise and effective therapeutic approaches to improve the prognosis and quality of life of cancer patients. Moreover, these strategies hold the promise to overcome resistance to conventional therapies, minimize side effects, and lead to more personalized treatment regimens, ultimately benefiting cancer treatment.

Amine-functionalized mesoporous silica nanoparticles decorated by silver nanoparticles for delivery of doxorubicin in breast and cervical cancer cells

Nanocarriers have demonstrated promising potential in the delivery of various anticancer drugs and in improving the efficiency of the treatment. In this study, silver nanoparticles (AgNPs) were green-synthesized using the extracts of different parts of the pomegranate plant, including the peel, flower petals, and calyx. To obtain the most efficient extract used for the green synthesis of AgNPs, all three types of synthesized nanoparticles were characterized. Then, (3-Aminopropyl) triethoxysilane-functionalized mesoporous silica nanoparticles (MSNs-APTES) decorated with AgNPs were fabricated via a one-pot green-synthesis method. AgNPs were directly coated on the surface of MSNs-APTES by adding pomegranate extract enriched with a source of reducing agent leading to converting the silver ion to AgNPs. The MSN-APTES-AgNPs (MSNs-AgNPs) have been thoroughly characterized using nanoparticle characterization techniques. In addition, DNA cleavage and hemolysis activities of the synthesized nanoparticles were analyzed, confirming the biocompatibility of synthesized nanoparticles. The Doxorubicin (DOX, as a breast/cervical anti-cancer drug) loading (42.8%) and release profiles were investigated via UV-visible spectroscopy. The fibroblast, breast cancer, and cervical cancer cells' viability against DOX-loaded nanoparticles were also studied. The results of this high drug loading, uniform shape, and small functionalized nanoparticles demonstrated its great potential for breast and cervical cancer management.

Anti-inflammatory action of silver nanoparticles in vivo: systematic review and meta-analysis

The aim of this study was to systematically review the literature to investigate whether silver nanoparticles (AgNPs) have an anti-inflammatory effect in vivo. The guidelines of PRISMA were applied, and a registration was made in PROSPERO. A personalized search of the PubMed, Web of Science, Scopus, Embase, Lilacs, and Google Scholar databases was conducted in September 2023. For the data analysis, the inverse variance in the random effects model was used. The tools of SYRCLE and GRADE were used to assess the risk of bias and the certainty of evidence, respectively. From the 9185 identified studies, 5685 duplicate studies were excluded; 52 were read in full text, and 7 were included in this review. Six studies were evaluated by the meta-analysis, and an increase in anti-inflammatory molecules (SMD -5.22; PI [-6.50, -3.94]) and an increase in anti-inflammatory ones (SMD 5.75; PI [3.79, 7.72]) were observed. Qualitative analysis showed a reduction in pro-inflammatory proteins and in the COX-2 pathway. It was concluded that AgNPs present an anti-inflammatory action in vivo through mechanisms involving the reduction of pro-inflammatory molecules and proteins, the increase of anti-inflammatory molecules, and selective inhibition of the COX-2 pathway.

Nanoparticles in Periodontitis Therapy: A Review of the Current Situation

Periodontitis is a disease of inflammation that affects the tissues supporting the periodontium. It is triggered by an immunological reaction of the gums to plaque, which leads to the destruction of periodontal attachment structures. Periodontitis is one of the most commonly recognized dental disorders in the world and a major factor in the loss of adult teeth. Scaling and root planing remain crucial for managing patients with persistent periodontitis. Nevertheless, exclusive reliance on mechanical interventions like periodontal surgery, extractions, and root planning is insufficient to halt the progression of periodontitis. In response to the problem of bacterial resistance, some researchers are committed to finding alternative therapies to antibiotics. In addition, some scholars focus on finding new materials to provide a powerful microenvironment for periodontal tissue regeneration and promote osteogenic repair. Nanoparticles possess distinct therapeutic qualities, including exceptional antibacterial, anti-inflammatory, and antioxidant properties, immunomodulatory capacities, and the promotion of bone regeneration ability, which made them can be used for the treatment of periodontitis. However, there are many problems that limit the clinical translation of nanoparticles, such as toxic accumulation in cells, poor correlation between in vitro and in vivo, and poor animal-to-human transmissibility. In this paper, we review the present researches on nanoparticles in periodontitis treatment from the perspective of three main categories: inorganic nanoparticles, organic nanoparticles, and nanocomposites (including nanofibers, hydrogels, and membranes). The aim of this review is to provide a comprehensive and recent update on nanoparticles-based therapies for periodontitis. The conclusion section summarizes the opportunities and challenges in the design and clinical translation of nanoparticles for the treatment of periodontitis.

Mesoporous Oxidized Mn-Ca Nanoparticles as Potential Antimicrobial Agents for Wound Healing

Managing chronic non-healing wounds presents a significant clinical challenge due to their frequent bacterial infections. Mesoporous silica-based materials possess robust wound-healing capabilities attributed to their renowned antimicrobial properties. The current study details the advancement of mesoporous silicon-loaded MnO and CaO molecules (HMn-Ca) against bacterial infections and chronic non-healing wounds. HMn-Ca was synthesized by reducing manganese chloride and calcium chloride by urotropine solution with mesoporous silicon as the template, thereby transforming the manganese and calcium ions on the framework of mesoporous silicon. The developed HMn-Ca was investigated using scanning electron microscopy (SEM), transmission electron microscope (TEM), ultraviolet-visible (UV-visible), and visible spectrophotometry, followed by the determination of Zeta potential. The production of reactive oxygen species (ROS) was determined by using the 3,3,5,5-tetramethylbenzidine (TMB) oxidation reaction. The wound healing effectiveness of the synthesized HMn-Ca is evaluated in a bacterial-infected mouse model. The loading of MnO and CaO inside mesoporous silicon enhanced the generation of ROS and the capacity of bacterial capture, subsequently decomposing the bacterial membrane, leading to the puncturing of the bacterial membrane, followed by cellular demise. As a result, treatment with HMn-Ca could improve the healing of the bacterial-infected wound, illustrating a straightforward yet potent method for engineering nanozymes tailored for antibacterial therapy.

Multifunctional mesoporous silica nanoparticles for biomedical applications

Mesoporous silica nanoparticles (MSNs) are recognized as a prime example of nanotechnology applied in the biomedical field, due to their easily tunable structure and composition, diverse surface functionalization properties, and excellent biocompatibility. Over the past two decades, researchers have developed a wide variety of MSNs-based nanoplatforms through careful design and controlled preparation techniques, demonstrating their adaptability to various biomedical application scenarios. With the continuous breakthroughs of MSNs in the fields of biosensing, disease diagnosis and treatment, tissue engineering, etc., MSNs are gradually moving from basic research to clinical trials. In this review, we provide a detailed summary of MSNs in the biomedical field, beginning with a comprehensive overview of their development history. We then discuss the types of MSNs-based nanostructured architectures, as well as the classification of MSNs-based nanocomposites according to the elements existed in various inorganic functional components. Subsequently, we summarize the primary purposes of surface-functionalized modifications of MSNs. In the following, we discuss the biomedical applications of MSNs, and highlight the MSNs-based targeted therapeutic modalities currently developed. Given the importance of clinical translation, we also summarize the progress of MSNs in clinical trials. Finally, we take a perspective on the future direction and remaining challenges of MSNs in the biomedical field.

Ag-Doped Metal-Organic Frameworks' Heterostructure for Sonodynamic Therapy of Deep-Seated Cancer and Bacterial Infection

Metal-organic frameworks (MOF) have attracted great potential in sonodynamic therapy (SDT) owing to large sonosensitizers' loading and fast reactive oxygen species' (ROS) diffusion; however, the low ligand-to-metal charge transfer efficiency sharply impairs the SDT effect. Herein, we report the design of MIL@Ag heterostructures with high electron-hole pairs separation efficiency and enhanced diverse ROS generation ability for deep-seated cancer treatment and bacterial infection. The MIL@Ag heterostructure is composed of Ti-based MOFs (named MIL), on which are in situ assembled silver nanoparticles (Ag NPs). The electrochemical experiments and density functional theory calculations verify that the introduction of Ag NPs can significantly improve the electron transfer efficiency and O2 adsorption capacity of MIL. Under ultrasound irradiation, the doped Ag NPs can trap the activated electrons from MIL to reduce surrounding O2 and produce superoxide radicals (•O2-), while the activated holes enable oxidizing H2O to produce hydroxyl radicals (•OH). Thus, they efficiently improve the therapeutic efficiency of SDT. MIL@Ag-PEG-mediated SDT implements A549 cancer cells' killing under a tissue barrier of 2 cm and eradicates the bacterial infection of Staphylococcus aureus, thus promoting wound healing. Therefore, MIL@Ag-PEG provides a promising strategy for augmenting SDT performance by rational heterostructure design of sonosensitizers.

Enhancing the therapeutic efficacy of nanoparticles for cancer treatment using versatile targeted strategies

Poor targeting of therapeutics leading to severe adverse effects on normal tissues is considered one of the obstacles in cancer therapy. To help overcome this, nanoscale drug delivery systems have provided an alternative avenue for improving the therapeutic potential of various agents and bioactive molecules through the enhanced permeability and retention (EPR) effect. Nanosystems with cancer-targeted ligands can achieve effective delivery to the tumor cells utilizing cell surface-specific receptors, the tumor vasculature and antigens with high accuracy and affinity. Additionally, stimuli-responsive nanoplatforms have also been considered as a promising and effective targeting strategy against tumors, as these nanoplatforms maintain their stealth feature under normal conditions, but upon homing in on cancerous lesions or their microenvironment, are responsive and release their cargoes. In this review, we comprehensively summarize the field of active targeting drug delivery systems and a number of stimuli-responsive release studies in the context of emerging nanoplatform development, and also discuss how this knowledge can contribute to further improvements in clinical practice.

Mesoporous silica-coated silver nanoparticles as ciprofloxacin/siRNA carriers for accelerated infected wound healing

The colonization of bacterial pathogens is a major concern in wound infection and becoming a public health issue. Herein, a core–shell structured Ag@MSN (silver core embedded with mesoporous silica, AM)-based nanoplatform was elaborately fabricated to co-load ciprofloxacin (CFL) and tumor necrosis factor-α (TNF-α) small interfering RNA (siTNF-α) (AMPC@siTNF-α) for treating the bacterial-infected wound. The growth of bacterial pathogens was mostly inhibited by released silver ions (Ag⁺) and CFL from AMPC@siTNF-α. Meanwhile, the loaded siTNF-α was internalized by macrophage cells, which silenced the expression of TNF-α (a pro-inflammatory cytokine) in macrophage cells and accelerated the wound healing process by reducing inflammation response. In the in vivo wound model, the Escherichia coli (E. coli)-infected wound in mice almost completely disappeared after treatment with AMPC@siTNF-α, and no suppuration symptom was observed during the course of the treatment. Importantly, this nanoplatform had negligible side effects both in vitro and in vivo. Taken together, this study strongly demonstrates the promising potential of AMPC@siTNF-α as a synergistic therapeutic agent for clinical wound infections.