Browsing by Author "Ritu Raj Patel"

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A novel nanotherapeutic approach: Dual action of green-synthesized silver nanoparticles from Clerodendrum serratum against MDR-ESKAPE pathogens with wound healing potential
(Editions de Sante, 2025) Ritu Raj Patel; Pandey Priya Arun; Vidyasagar; Aradhana Mishra; Sudhir Kumar Singh; Samer Singh; Brahmeshwar Mishra; Meenakshi Singh
The rapid emergence of multidrug-resistant (MDR) ESKAPE pathogens in healthcare settings, particularly chronic wound infections presents a critical challenge. Moreover, with antibiotic resistance reaching alarming levels and conventional treatments failing against biofilm-associated infections, there is an urgent need to develop novel and effective therapeutic strategies. In this study, silver nanoparticles (AgNPs) synthesized via a green method using Clerodendrum serratum leaf extract, along with their polyethylene glycol-coated derivative (PEG-AgNPs), were evaluated for their antibacterial and wound-healing potential. PEG-AgNPs demonstrated superior antibacterial efficacy, with significantly lower minimum inhibitory concentration (MIC) values (0.3906–12.5 μg/mL) compared to AgNPs (3.125–25 μg/mL). Time-kill studies further confirmed that PEG-AgNPs exhibited enhanced bactericidal properties. Mechanistic investigations revealed that their antibacterial activity resulted from bacterial cell membrane rupture, leading to cytoplasmic content leakage, as confirmed by FACS analysis. Furthermore, biofilm formation by these pathogens was evaluated, and the nanoparticles demonstrated remarkable anti-biofilm potency, particularly against Acinetobacter baumannii and Pseudomonas aeruginosa. The LC-MS analysis of C. serratum leaf extract revealed bioactive phytoconstituents, which were subjected to molecular docking studies against biofilm-forming factors in P. aeruginosa and A. baumannii confirming strong binding interactions. Additionally, the prepared nanoparticle-based gel formulations significantly enhanced in vivo wound healing in both uninfected and infected (A. baumannii and P. aeruginosa) wounds, highlighting their potential as dual-action therapeutic agents for inhibiting MDR pathogens and simultaneously promoting tissue regeneration. Therefore, these findings suggest that green synthesized nanoparticles, particularly PEG-AgNPs hold promise as novel interventions for combating MDR-ESKAPE infected wounds. © 2025 Elsevier B.V.
Exploring Metal Complexes for Cancer Treatment: Mechanistic Insights and Therapeutic Potential
(Elsevier B.V., 2025) Pandey Priya Arun; Ritu Raj Patel; Sudhir Kumar Singh; Kailash Parmar; Meenakshi Singh
Recent research in the field of cancer therapeutics has explored various potential drug treatments supported by metal- based scaffolds, following the investigation and clinical application of cisplatin, which has emerged as an active anti- cancer drug. Organometallic compounds have gained significant attention in cancer therapy due to their unique ability to interact with biomolecules, providing targeted and efficient anticancer activity. This has led to the development of metallodrugs, which encompass metal-based compounds with a wider range of functionalities and mechanisms of action compared to organic molecules. However, platinum-based metal complexes have limitations in their spectrum of anti-cancer activities, often resulting in side effects and resistance. To address these challenges, extensive research has been conducted to study and develop effective alternatives to platinum-based anticancer medications, encompassing metals such as ruthenium, vanadium, copper, iron, manganese, zinc, and cobalt. Metallodrugs represent a promising new category of potential cancer treatments, renewing interest in pursuing effective anti-cancer therapies. Nanomedicine strategies offer an efficient drug delivery platform to overcome the limitations of conventional chemotherapy and enhance therapeutic efficacy. Multifunctional nanomaterials have demonstrated the ability to improve drug delivery by increasing bioavailability and optimizing pharmacokinetics, thereby enhancing the effectiveness of chemotherapeutic agents in overcoming multidrug resistance (MDR). By gaining a deeper understanding of their distinct characteristics and mechanisms of action, there is potential to explore avenues for developing targeted and effective anti-cancer treatments. This review explores the intricate details of various metal complexes, highlighting their unique properties and modes of action in combating cancer while providing valuable insights into their potential as promising agents for developing effective and targeted anticancer therapies, paving the way for future advancements in the field. © 2025 Elsevier B.V.
Facile green synthesis of silver nanoparticles derived from the medicinal plant Clerodendrum serratum and its biological activity against Mycobacterium species
(Elsevier Ltd, 2024) Vidyasagar; Ritu Raj Patel; Sudhir Kumar Singh; Deepa Dehari; Gopal Nath; Meenakshi Singh
The emergence of multidrug-resistant mycobacterial strains is a significant crisis that has led to higher treatment failure rates and more toxic and expensive medications for tuberculosis (TB). The urgent need to develop novel therapeutics has galvanized research interest towards developing alternative antimicrobials such as silver nanoparticles (AgNPs). The current study focused on the anti-mycobacterial activity of green-synthesized AgNPs and its polyethylene glycol encapsulated derivative (PEG-AgNPs) with improved stability using the leaves extract of Clerodendrum serratum. Different characterization methods were used to analyze them. DLS analysis revealed a lower polydispersity index of PEG-AgNPs, suggesting a more uniform size distribution than that of AgNPs. The HR-TEM results revealed that the AgNPs and PEG-AgNPs have predominantly spherical shapes in the size range of 9–35 nm and 15–60 nm, respectively, while positive values of Zeta potential indicate their stability. FTIR-ATR analysis confirmed the presence of functional groups responsible for reducing and capping the bio-reduced AgNPs, whereas the XRD data established its crystalline nature. Impressively, the PEG-AgNPs exhibited maximum inhibitory activity against different Tubercular and Non-Tuberculous Mycobacterium species i.e., Mycobacterium smegmatis, Mycobacterium fortuitum and Mycobacterium marinum, relative to those of AgNPs and Linezolid. The flow cytometry assay showed that the anti-mycobacterial action was mediated by an increase in cell wall permeability. Notably, the results of AFM confirm their ability to inhibit mycobacterial biofilm significantly. We demonstrated the nontoxic nature of these AgNPs, explicated by the absence of hemolytic activity against human RBCs. Overall, the results suggest that PEG-AgNPs could offer a novel therapeutic approach with potential anti-mycobacterial activity and can overcome the limitations of existing TB therapies. © 2024 The Authors
Fmoc-Appended Redox Active Aromatic Amino Acids Capped Nanoparticles Embodied Sustainable Antibacterial Catalytic Hydrogels for the Production of Value-Added Chemical
(John Wiley and Sons Inc, 2025) Swaraj Ganesh Gaonkar; Ritu Raj Patel; Meenakshi Singh; Biplab Mondal; Sunil Kumar Meena; Subhasish Roy
In this study, the hydrogelations of Fmoc-Tyr-OH (Fmoc-Y) and Fmoc-Trp-OH (Fmoc-W) have been investigated in 50 mm phosphate buffer (saline) of pH 7.4. Gold and silver nanoparticles have been synthesized in situ within these hydrogels under physiological conditions without using any toxic reducing agents to achieve hybrid hydrogels formation successfully. The nanoparticles formation kinetics have been monitored through UV-vis spectroscopy. Native and hybrid hydrogels have been characterized by using UV-vis, fluorescence, FTIR, XRD, FE-SEM, and HR-TEM analyses. Rheological measurements revealed their mechanical strength and thixotropic behaviour. Moreover, both native and hybrid hydrogels show potent antibacterial activities against both Gram-positive and Gram-negative bacteria. Interestingly, these as-synthesized gold nanoparticles containing hybrid hydrogels and their xerogels exhibited excellent catalytic activities for the reduction of p-nitrophenol (p-NP) to p-aminophenol (p-AP), monitored through time-dependent UV-vis spectroscopy. These catalysts retained their activities over multiple cycles, highlighting their reusability and stability. To the best of our literature knowledge, this is a green, sustainable, fastest, economical and effective reduction reaction of hazardous p-NP using amino acids-stabilized gold nanoparticles containing xerogels in water ever reported to produce value-added chemical precursor p-AP for the syntheses of various drug molecules. This is a minimalistic approach to device biomaterials-based advanced sustainable system for environmental remediation and value-added chemical production. © 2025 Wiley-VCH GmbH.
Green synthesis of silver nanoparticles: methods, biological applications, delivery and toxicity
(Royal Society of Chemistry, 2023) None Vidyasagar; Ritu Raj Patel; Sudhir Kumar Singh; Meenakshi Singh
The advent of nanotechnology profoundly transformed the pharmaceutical sciences and greatly enhanced the diagnostics and treatment of various diseases that threaten human life. Several metallic nanoparticles are extensively used as nanomedicines due to their potential therapeutic applications. Among them, silver nanoparticles are remarkable due to their unique chemical and physical properties. This review discusses types of nanoparticles, and green synthesis methods along with their reduction mechanisms, involving economically viable reducing materials like algae, seaweeds and flowers. Apart from environment-friendly methods, several biological activities such as wound healing, antibacterial, antifungal, anti-tumour, anti-viral, etc., are described in detail. Consequently, we have focused on how silver nanoparticles enhance targeted drug delivery and the mechanism of drug release along with their toxic effects. © 2023 RSC.
Mycobacterial biofilms: Understanding the genetic factors playing significant role in pathogenesis, resistance and diagnosis
(Elsevier Inc., 2024) Ritu Raj Patel; Pandey Priya Arun; Sudhir Kumar Singh; Meenakshi Singh
Even though the genus Mycobacterium is a diverse group consisting of a majority of environmental bacteria known as non-tuberculous mycobacteria (NTM), it also contains some of the deadliest pathogens (Mycobacterium tuberculosis) in history associated with chronic disease called tuberculosis (TB). Formation of biofilm is one of the unique strategies employed by mycobacteria to enhance their ability to survive in hostile conditions. Biofilm formation by Mycobacterium species is an emerging area of research with significant implications for understanding its pathogenesis and treatment of related infections, specifically TB. This review provides an overview of the biofilm-forming abilities of different species of Mycobacterium and the genetic factors influencing biofilm formation with a detailed focus on M. tuberculosis. Biofilm-mediated resistance is a significant challenge as it can limit antibiotic penetration and promote the survival of dormant mycobacterial cells. Key genetic factors promoting biofilm formation have been explored such as the mmpL genes involved in lipid transport and cell wall integrity as well as the groEL gene essential for mature biofilm formation. Additionally, biofilm-mediated antibiotic resistance and pathogenesis highlighting the specific niches, sites of infection along with the possible mechanisms of biofilm dissemination have been discussed. Furthermore, drug targets within mycobacterial biofilm and their role as potential biomarkers in the development of rapid diagnostic tools have been highlighted. The review summarises the current understanding of the complex nature of Mycobacterium biofilm and its clinical implications, paving the way for advancements in the field of disease diagnosis, management and treatment against its multi-drug resistant species. © 2024 Elsevier Inc.
Overcoming antimicrobial resistance: Phage therapy as a promising solution to combat ESKAPE pathogens
(Elsevier B.V., 2025) Ritu Raj Patel; Pandey Priya Arun; Sudhir Kumar Singh; Meenakshi Singh
Objective The global escalation of antimicrobial resistance (AMR) has intensified the search for alternative therapies, with bacteriophage (phage) therapy re-emerging as a promising solution. This review aims to critically evaluate the therapeutic potential of phage therapy against multidrug-resistant (MDR) ESKAPE pathogens, which are major contributors to hospital-acquired infections. The review discusses the distinct antibacterial strategies of phage namely, targeted lysis, enzymatic biofilm disruption, and synergy with antibiotics. Methods A comprehensive literature review was conducted focusing on the mechanisms of phage antibacterial activity and the molecular regulation of lytic and lysogenic life cycles, highlighting the therapeutic importance of the lytic-lysogenic switch. It also explores the integration of nanotechnology-based delivery systems that enhances therapeutic efficacy. Recent advances in phage engineering, including CRISPR-Cas technologies and synthetic biology approaches, were also analyzed to understand their contribution to optimizing phage efficacy. Results Phage therapy demonstrates multiple antibacterial mechanisms, including targeted bacterial lysis, enzymatic biofilm disruption, and synergistic interactions with antibiotics. Advanced delivery systems such as liposomes, hydrogels, nanofibers, and nanoemulsions enhance phage stability and retention by overcoming physiological barriers like gastric acidity, enzymatic degradation, and immune clearance. Clinical evidence from compassionate use cases and early-phase trials highlights the safety and therapeutic promise of phage therapy. Conclusions Phage therapy represents a versatile and sustainable approach to combat multidrug-resistant infections. While regulatory, resistance, and scalability challenges remain, continued integration of microbiology, nanotechnology, and clinical research may enable its transition from experimental to mainstream therapeutic application in the post-antibiotic era. © 2025 Elsevier Ltd and International Society of Antimicrobial Chemotherapy.
Recent advances in inhibitor development and metabolic targeting in tuberculosis therapy
(Academic Press, 2025) Ritu Raj Patel; Vidyasagar; Sudhir Kumar Singh; Meenakshi Singh
Despite being a preventable and treatable disease, tuberculosis (TB) remained the second leading infectious cause of death globally in 2022, surpassed only by COVID-19. The death rate from TB is influenced by numerous factors that include antibiotic drug resistance, noncompliance with chemotherapy by patients, concurrent infection with the human immunodeficiency virus, delayed diagnosis, varying effectiveness of the Bacille-Calmette-Guerin vaccine, and other factors. Even with the recent advances in our knowledge of Mycobacterium tuberculosis and the accessibility of advanced genomic tools such as proteomics and microarrays, alongside modern methodologies, the pursuit of next-generation inhibitors targeting distinct or multiple molecular pathways remains essential to combat the increasing antimicrobial resistance. Hence, there is an urgent need to identify and develop new drug targets against TB that have unique mechanisms. Novel therapeutic targets might encompass gene products associated with various aspects of mycobacterial biology, such as transcription, metabolism, cell wall formation, persistence, and pathogenesis. This review focuses on the present state of our knowledge and comprehension regarding various inhibitors targeting key metabolic pathways of M. tuberculosis. The discussion encompasses small molecule, synthetic, peptide, natural product and microbial inhibitors and navigates through promising candidates in different phases of clinical development. Additionally, we explore the crucial enzymes and targets involved in metabolic pathways, highlighting their inhibitors. The metabolic pathways explored include nucleotide synthesis, mycolic acid synthesis, peptidoglycan biosynthesis, and energy metabolism. Furthermore, advancements in genetic approaches like CRISPRi and conditional expression systems are discussed, focusing on their role in elucidating gene essentiality and vulnerability in Mycobacteria. © 2025 Elsevier Ltd