Enhanced antibacterial effects of green synthesized ZnO NPs using Aristolochia indica against Multi-drug resistant bacterial pathogens from Diabetic Foot Ulcer

Catharanthus roseus-mediated CuAl2O4 nanocomposites for evaluation of killing kinetics

The present article portrayed on the killing kinetic of human pathogenic bacteria using bioinspired mesoporous CuAl2O4 nanocomposites (NCs). The NCs was fabricated using leaf extract of medicinal plant Catharanthus roseus (CR) as a green reducer and stabilizer. As bio-fabricated material was calcined at 800 °C and characterized by several analytical techniques like X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FT-IR), Ultraviolet-Visible Diffuse Reflectance Spectroscopy (UV-DRS), Energy Dispersive X-Ray Spectroscopy (EDS), X-Ray Photoelectron Spectroscopy (XPS), Raman, Brunauer-Emmett-Teller (BET), Scanning Electron Microscopy (SEM), and Transmission Electron Microscopy (TEM) to authenticate its structure, phase, chemical bonding, chemical state, size and morphology behaviors. XRD and TEM revealed a reduced crystallite and nanoscale sizes of biosynthesized NCs. Moreover, XRD study exposed a cubic-structure of material, while transmission electron microscopy rendered an average particles size in range 10-15 nm. However, BET profile advocates a mesoporous nature of the particles. An effective biological molecular docking modulation assessed by substituting natural inhibitor by bioinspired NCs, while the protein PDB ID 4Z8D FabH as a receptor site for the present investigation. After assessment of molecular docking examination, the antibacterial activity of bioinspired NCs were performed against Staphylococcus aureus, Bacillus subtillis, Klebsiella pneumoniae and Escherichia coli using agar-well method. The broth culture method was employed on different pathogenic strains by kinetic growth assays and colony forming unit.

Aristolochia bracteolata flower extract based phytosynthesis and characterization of AgNPs: Antimicrobial, antidiabetic, and antioxidant activities potential assessment

The study was carried out to evaluate the effectiveness of the Aristolochia bracteolata water flower extract-mediated AgNPs synthesis and assess their antimicrobial potential. According to the experimental and analytical results, A. bracteolata flower extract can produce valuable AgNPs. The characteristic features of these AgNPs were assessed with UV-visible spectrophotometer, Fourier transform-infrared spectroscopy, Transmission Electron Microscope, Scanning Electron Microscopy, as well as. Under UV-vis. spectrum results, showed major peak at 430 nm and recorded essential functional groups responsible for reducing, capping, and stabilizing AgNPs by FT-IR analysis. In addition, the size and shape of the synthesized AgNPs were found as 21.11-25.17 nm and spherical/octahedral shape. The A. bracteolata fabricated NPs showed remarkable antimicrobial activity against fish bacterial pathogens (V. parahaemolytics, Serratia sp., B. subtilis, and E. coli) as well as common fungal pathogens (A. niger, C. albicans, A. flavus, and A. terreus) at the quantity of 100 μg mL-1 than positive controls. Nevertheless, it was not effective against human bacterial pathogens. It concludes that AgNPs synthesized from A. bracteolata aqueous flower extract have excellent antimicrobial activity and may have a variety of biomedical applications.

Zinc Oxide-Based Nanomaterials for Microbiostatic Activities: A Review

The world is fighting infectious diseases. Therefore, effective antimicrobials are required to prevent the spread of microbes and protect human health. Zinc oxide (ZnO) nano-materials are known for their antimicrobial activities. Because of their distinctive physical and chemical characteristics, they can be used in medical and environmental applications. ZnO-based composites are among the leading sources of antimicrobial research. They are effective at killing (microbicidal) and inhibiting the growth (microbiostatic) of numerous microorganisms, such as bacteria, viruses, and fungi. Although most studies have focused on the microbicidal features, there is a lack of reviews on their microbiostatic effects. This review provides a detailed overview of available reports on the microbiostatic activities of ZnO-based nano-materials against different microorganisms. Additionally, the factors that affect the efficacy of these materials, their time course, and a comparison of the available antimicrobials are highlighted in this review. The basic properties of ZnO, challenges of working with microorganisms, and working mechanisms of microbiostatic activities are also examined. This review underscores the importance of further research to better understand ZnO-based nano-materials for controlling microbial growth.

Insights into the mechanisms of diabetic wounds: pathophysiology, molecular targets, and treatment strategies through conventional and alternative therapies

Diabetes mellitus is a prevalent cause of mortality worldwide and can lead to several secondary issues, including DWs, which are caused by hyperglycemia, diabetic neuropathy, anemia, and ischemia. Roughly 15% of diabetic patient's experience complications related to DWs, with 25% at risk of lower limb amputations. A conventional management protocol is currently used for treating diabetic foot syndrome, which involves therapy using various substances, such as bFGF, pDGF, VEGF, EGF, IGF-I, TGF-β, skin substitutes, cytokine stimulators, cytokine inhibitors, MMPs inhibitors, gene and stem cell therapies, ECM, and angiogenesis stimulators. The protocol also includes wound cleaning, laser therapy, antibiotics, skin substitutes, HOTC therapy, and removing dead tissue. It has been observed that treatment with numerous plants and their active constituents, including Globularia Arabica, Rhus coriaria L., Neolamarckia cadamba, Olea europaea, Salvia kronenburgii, Moringa oleifera, Syzygium aromaticum, Combretum molle, and Myrtus communis, has been found to promote wound healing, reduce inflammation, stimulate angiogenesis, and cytokines production, increase growth factors production, promote keratinocyte production, and encourage fibroblast proliferation. These therapies may also reduce the need for amputations. However, there is still limited information on how to prevent and manage DWs, and further research is needed to fully understand the role of alternative treatments in managing complications of DWs. The conventional management protocol for treating diabetic foot syndrome can be expensive and may cause adverse side effects. Alternative therapies, such as medicinal plants and green synthesis of nano-formulations, may provide efficient and affordable treatments for DWs.

Green synthesis of zinc oxide nanoparticles using novel bacterium strain (Bacillus subtilis NH1-8) and their in vitro antibacterial and antibiofilm activities against Salmonellatyphimurium

Zinc oxide nanoparticles (ZnO NPs) are used in a range of applications, including food packaging, preservation, and storage. In the current investigation, extracellular green synthesis of ZnO NPs through an simple, eco-friendly, and rapid approach using a novel bacterial strain (Bacillus subtilis NH1-8) was studied. To assess the morphological, optical, and structural properties of ZnO NPs, transmission electron microscopy (TEM), energy-dispersive X-ray (EDX), scanning electron microscopy (SEM), fourier transform infrared (FTIR) spectroscopy, ultraviolet-visible (UV-vis) spectroscopy, and X-ray diffraction (XRD) techniques were carried out. In addition, disk diffusion, minimum bactericidal concentration (MBC), and minimum inhibitory concentration (MIC) methods were performed to determine the antibacterial activity of ZnO NPs. The average size of biosynthesized ZnO NPs was 39 nm, exhibiting semi-spherical, which was confirmed by TEM analyses. The UV-vis spectroscopy exhibited the absorption peak at 200-800nm. The ZnO NPs have shown effective antimicrobial and antibiofilm activities against S. typhimurium. Thus, biosynthesized ZnO NPs could be exploited as a breakthrough technology in the surface coating of food containers and cans to minimize contamination by S. typhimurium.

Aldose Reductase and Protein Glycation Inhibitory Activity of Dark Chocolate-Assisted Zinc Oxide Nanoparticles

Introduction One of the most common health issues that the global population is dealing with is the associated complications of diabetes, which encompasses cataracts, peripheral neuropathy, vascular damage, impaired wound healing, retinal issues, and arterial wall stiffening. The present study is aimed to evaluate the effect of dark chocolate and its assisted zinc oxide nanoparticles against diabetes-associated complications. Materials and methods Zinc oxide nanoparticles were synthesized using commercially dark chocolate (DC-ZnO NP). The synthesized DC-ZnO NPs were evaluated against recombinant aldose reductase (AR) activity and the formation of advanced glycation end products (AGEs). Aminoguanidine and gallic acid were used as reference standards for AGE assay and sorbitol accumulation inhibition, respectively. Results The results of the present study showed that green synthesized DC-ZnO NP had a significant dose-dependent inhibitory activity on both AR and AGEs. The inhibitory activity was compared to that of quercetin and aminoguanidine, respectively. Conclusion Targeting the endogenous antioxidant systems like AGEs and AR enzymes seems to provide a promising therapeutic approach, thus concluding that ZnO-NP could be a promising agent for treating diabetes-related complications such as diabetic retinopathy, diabetic nephropathy, and diabetic neuropathy that provide grounds for further clinical investigations and trials.

Biosynthesis of Functional Silver Nanoparticles Using Callus and Hairy Root Cultures of Aristolochia manshuriensis

This study delves into the novel utilization of Aristolochia manshuriensis cultured cells for extracellular silver nanoparticles (AgNPs) synthesis without the need for additional substances. The presence of elemental silver has been verified using energy-dispersive X-ray spectroscopy, while distinct surface plasmon resonance peaks were revealed by UV-Vis spectra. Transmission and scanning electron microscopy indicated that the AgNPs, ranging in size from 10 to 40 nm, exhibited a spherical morphology. Fourier-transform infrared analysis validated the abilty of A. manshuriensis extract components to serve as both reducing and capping agents for metal ions. In the context of cytotoxicity on embryonic fibroblast (NIH 3T3) and mouse neuroblastoma (N2A) cells, AgNPs demonstrated varying effects. Specifically, nanoparticles derived from callus cultures exhibited an IC50 of 2.8 µg/mL, effectively inhibiting N2A growth, whereas AgNPs sourced from hairy roots only achieved this only at concentrations of 50 µg/mL and above. Notably, all studied AgNPs' treatment-induced cytotoxicity in fibroblast cells, yielding IC50 values ranging from 7.2 to 36.3 µg/mL. Furthermore, the findings unveiled the efficacy of the synthesized AgNPs against pathogenic microorganisms impacting both plants and animals, including Agrobacterium rhizogenes, A. tumefaciens, Bacillus subtilis, and Escherichia coli. These findings underscore the effectiveness of biotechnological methodologies in offering advanced and enhanced green nanotechnology alternatives for generating nanoparticles with applications in combating cancer and infectious disorders.

Zinc Oxide Nanoparticles Biosynthesized by Eriobotrya japonica Leaf Extract: Characterization, Insecticidal and Antibacterial Properties

Zinc oxide nanoparticles (ZnO-NPs) have gained significant attention in nanotechnology due to their unique properties and potential applications in various fields, including insecticidal and antibacterial activities. The ZnO-NPs were biosynthesized by Eriobotrya japonica leaf extract and characterized by various techniques such as UV-visible (UV-vis) spectrophotometer, X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), dynamic light scattering (DLS), and zeta potential analysis. The results of SEM revealed that NPs were irregular and spherical-shaped, with a diameter between 5 and 27 nm. Meanwhile, DLS supported that the measured size distributions were 202.8 and 94.7 nm at 11.1° and 90.0°, respectively, which supported the polydisperse nature of NPs, and the corresponding zeta potential was -20.4 mV. The insecticidal activity of the produced ZnO-NPs was determined against the adult stage of coleopteran pests, Sitophilus oryzae (Linnaeus) (Curculionidae) and Tribolium castaneum (Herbst) (Tenebrionidae). The LC50 values of ZnO-NPs against adults of S. oryzae and T. castaneum at 24 h of exposure were 7125.35 and 5642.65 μg/mL, respectively, whereas the LC90 values were 121,824.56 and 66,825.76 μg/mL, respectively. Moreover, the biosynthesized nanoparticles exhibited antibacterial activity against three potato bacterial pathogens, and the size of the inhibition zone was concentration-dependent. The data showed that the inhibition zone size increased with an increase in the concentration of nanoparticles for all bacterial isolates tested. The highest inhibition zone was observed for Ralstonia solanacearum at a concentration of 5 µg/mL, followed by Pectobacterium atrosepticum and P. carotovorum. Eventually, ZnO-NPs could be successfully used as an influential agent in pest management programs against stored-product pests and potato bacterial diseases.

Recent development of metal oxides and chalcogenides as antimicrobial agents

Pathogenic microbes are a major concern in hospitals and other healthcare facilities because they affect the proper performance of medical devices, surgical devices, etc. Due to the antimicrobial resistance or multidrug resistance, combatting these microbial infections has grown to be a significant research area in science and medicine as well as a critical health concern. Antibiotic resistance is where microbes acquire and innately exhibit resistance to antimicrobial agents. Therefore, the development of materials with promising antimicrobial strategy is a necessity. Amongst other available antimicrobial agents, metal oxide and chalcogenide-based materials have shown to be promising antimicrobial agents due to their inherent antimicrobial activity as well as their ability to kill and inhibit the growth of microbes effectively. Moreover, other features including the superior efficacy, low toxicity, tunable structure, and band gap energy has makes metal oxides (i.e. TiO₂, ZnO, SnO₂ and CeO₂ in particular) and chalcogenides (Ag₂S, MoS₂, and CuS) promising candidates for antimicrobial applications as illustrated by examples discussed in this review.

Advanced polymer hydrogels that promote diabetic ulcer healing: mechanisms, classifications, and medical applications

Diabetic ulcers (DUs) are one of the most serious complications of diabetes mellitus. The application of a functional dressing is a crucial step in DU treatment and is associated with the patient's recovery and prognosis. However, traditional dressings with a simple structure and a single function cannot meet clinical requirements. Therefore, researchers have turned their attention to advanced polymer dressings and hydrogels to solve the therapeutic bottleneck of DU treatment. Hydrogels are a class of gels with a three-dimensional network structure that have good moisturizing properties and permeability and promote autolytic debridement and material exchange. Moreover, hydrogels mimic the natural environment of the extracellular matrix, providing suitable surroundings for cell proliferation. Thus, hydrogels with different mechanical strengths and biological properties have been extensively explored as DU dressing platforms. In this review, we define different types of hydrogels and elaborate the mechanisms by which they repair DUs. Moreover, we summarize the pathological process of DUs and review various additives used for their treatment. Finally, we examine the limitations and obstacles that exist in the development of the clinically relevant applications of these appealing technologies. This review defines different types of hydrogels and carefully elaborate the mechanisms by which they repair diabetic ulcers (DUs), summarizes the pathological process of DUs, and reviews various bioactivators used for their treatment.

Multi-drug resistant ESKAPE pathogens and the uses of plants as their antimicrobial agents

Infections by ESKAPE (Enterococcus sp., Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.) pathogens cause major concern due to their multi-drug resistance (MDR). The ESKAPE pathogens are frequently linked to greater mortality, diseases, and economic burden in healthcare worldwide. Therefore, the use of plants as a natural source of antimicrobial agents provide a solution as they are easily available and safe to use. These natural drugs can also be enhanced by incorporating silver nanoparticles and combining them with existing antibiotics. By focussing the attention on the ESKAPE organisms, the MDR issue can be addressed much better.

Emerging Antimicrobial and Immunomodulatory Fiber-Based Scaffolding Systems for Treating Diabetic Foot Ulcers

Diabetic foot ulcers (DFUs) are one of the main complications of diabetes and are characterized by their complexity and severity, which are frequently aggravated by overexpressed inflammatory factors and polymicrobial infections. Most dressing systems offer a passive action in the treatment of DFUs, being frequently combined with antibiotic or immunomodulatory therapies. However, in many instances due to these combined therapies' inability to properly fight microbial presence, and provide a suitable, breathable and moist environment that is also capable of protecting the site from secondary microbial invasions or further harm, aggravation of the wound state is unavoidable and lower limb amputations are necessary. Considering these limitations and knowing of the urgent demand for new and more effective therapeutic systems for DFU care that will guarantee the quality of life for patients, research in this field has boomed in the last few years. In this review, the emerging innovations in DFU dressing systems via fiber-based scaffolds modified with bioactive compounds have been compiled; data focused on the innovations introduced in the last five years (2017-2022). A generalized overview of the classifications and constraints associated with DFUs healing and the bioactive agents, both antimicrobial and immunomodulatory, that can contribute actively to surpass such issues, has also been provided.

Smart nano-in-microparticles to tackle bacterial infections in skin tissue engineering

Chronic wounds (resulting from underlying disease, metabolic disorders, infections, trauma, and even tumours) pose significant health problems. In this work, microparticles, based on polysaccharides (maltodextrin or dextran) and amino acids, and doped with antibacterial nanoparticles (CuO or ZnO NPs) are designed. Smart nano-in-microparticles with a hierarchical 3D structure are developed. The ultimate goal aims at an innovative platform to achieve skin repair and to manage skin colonization by avoiding infection that could delay and even impair the healing process. The microparticles are prepared by spray-drying and cross-linked by heating, to obtain insoluble scaffolds able to facilitate cell proliferation in the wound bed. The nano-in-microparticles are characterized using a multidisciplinary approach: chemico-physical properties (SEM, SEM-EDX, size distribution, swelling and degradation properties, structural characterization - FTIR, XRPD, SAXS - mechanical properties, surface zeta potential) and preclinical properties (in vitro biocompatibility and whole-blood clotting properties, release studies and antimicrobial properties, and in vivo safety and efficacy on murine burn/excisional wound model) were assessed. The hierarchical 3D nano-in microparticles demonstrate to promote skin tissue repair in a preclinical study, indicating that this platform deserves particular attention and further investigation will promote the prototypes translation to clinics.

Photothermally responsive chitosan-coated iron oxide nanoparticles for enhanced eradication of bacterial biofilms

This work developed a pH/NIR responsive antibacterial agent (CS-FeNPs) composed of chitosan (CS) and Fe₃O₄ nanoparticles (FeNPs). CS triggers bacterial attraction through surface charge, while Fe acts as a photothermal agent (PTA). The CS-Fe NPs exhibited antibacterial and antibiofilm activity against both bacteria (G+/G-). However, higher activity was observed against bacteria (G-) due to electrostatic interactions. The CS-FeNPs bind with the bacterial membrane through electrostatic interactions and disturb bacterial cells. Later, in an acidic environment, CS-FeNPs bind with bacterial membrane, and NIR irradiation leads the antibacterial activity. CS-FeNPs exhibited a potential photothermal conversion efficiency (η) of 21.53 %. Thus, it converts NIR irradiation into heat to kill the bacterial pathogen. The CS-FeNPs were found to be less cytotoxic with great antibacterial efficiency on planktonic bacteria and their biofilm, which indicates that they deserve to develop potential and safe treatment strategies for the treatment of bacterial infections.

Influence of sugar concentration on the vesicle compactness, deformation and membrane poration induced by anionic nanoparticles

Sugar plays a vital role in the structural and functional characteristics of cells. Hence, the interaction of NPs with cell membranes in the presence of sugar concentrations is important for medicinal and pharmacological innovations. This study integrated three tools: giant unilamellar vesicles (GUVs), anionic magnetite nanoparticles (NPs), and sugar concentrations, to understand a simplified mechanism for interactions between the vesicle membranes and NPs under various sugar concentrations. We focused on changing the sugar concentration in aqueous solution; more precisely, sucrose inside the GUVs and glucose outside with equal osmolarity. 1,2-dioleoyl-sn-glycero-3-phospho-(1′-rac-glycerol) (sodium salt) (DOPG) and 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) were used to prepare the charged membranes of 40mole%DOPG/60mole%DOPC-GUVs, whereas only DOPC was used to prepare the neutral membranes. Phase contrast fluorescence microscopy shows that the adherence of 18 nm magnetite NPs with anionic charge depends on the sugar concentration. The alterations of GUVs induced by the NPs are characterized in terms of i) vesicle compactness, ii) deformation, and iii) membrane poration. The presence of sugar provides additional structural stability to the GUVs and reduces the effects of the NPs with respect to these parameters; more precisely, the higher the sugar concentration, the smaller the alteration induced by the NPs. The differences in NPs effects are explained by the change in the type of interaction between sugar molecules and lipid membranes, namely enthalpy and entropy-driven interaction, respectively. In addition, such alterations are influenced by the surface charge density of the lipid bilayer. The surface pressure of membranes due to the adsorption of NPs is responsible for inducing the poration in membranes. The differences in deformation and poration in charged and neutral GUVs under various sugar concentrations are discussed based on the structure of the head of lipid molecules.

A Critical Review of the Antimicrobial and Antibiofilm Activities of Green-Synthesized Plant-Based Metallic Nanoparticles

Metallic nanoparticles (MNPs) produced by green synthesis using plant extracts have attracted huge interest in the scientific community due to their excellent antibacterial, antifungal and antibiofilm activities. To evaluate these pharmacological properties, several methods or protocols have been successfully developed and implemented. Although these protocols were mostly inspired by the guidelines from national and international regulatory bodies, they suffer from a glaring absence of standardization of the experimental conditions. This situation leads to a lack of reproducibility and comparability of data from different study settings. To minimize these problems, guidelines for the antimicrobial and antibiofilm evaluation of MNPs should be developed by specialists in the field. Being aware of the immensity of the workload and the efforts required to achieve this, we set out to undertake a meticulous literature review of different experimental protocols and laboratory conditions used for the antimicrobial and antibiofilm evaluation of MNPs that could be used as a basis for future guidelines. This review also brings together all the discrepancies resulting from the different experimental designs and emphasizes their impact on the biological activities as well as their interpretation. Finally, the paper proposes a general overview that requires extensive experimental investigations to set the stage for the future development of effective antimicrobial MNPs using green synthesis.

Exploring the Journey of Zinc Oxide Nanoparticles (ZnO-NPs) toward Biomedical Applications

The field of nanotechnology is concerned with the creation and application of materials having a nanoscale spatial dimensioning. Having a considerable surface area to volume ratio, nanoparticles have particularly unique properties. Several chemical and physical strategies have been used to prepare zinc oxide nanoparticles (ZnO-NPs). Still, biological methods using green or natural routes in various underlying substances (e.g., plant extracts, enzymes, and microorganisms) can be more environmentally friendly and cost-effective than chemical and/or physical methods in the long run. ZnO-NPs are now being studied as antibacterial agents in nanoscale and microscale formulations. The purpose of this study is to analyze the prevalent traditional method of generating ZnO-NPs, as well as its harmful side effects, and how it might be addressed utilizing an eco-friendly green approach. The study's primary focus is on the potential biomedical applications of green synthesized ZnO-NPs. Biocompatibility and biomedical qualities have been improved in green-synthesized ZnO-NPs over their traditionally produced counterparts, making them excellent antibacterial and cancer-fighting drugs. Additionally, these ZnO-NPs are beneficial when combined with the healing processes of wounds and biosensing components to trace small portions of biomarkers linked with various disorders. It has also been discovered that ZnO-NPs can distribute and sense drugs. Green-synthesized ZnO-NPs are compared to traditionally synthesized ones in this review, which shows that they have outstanding potential as a potent biological agent, as well as related hazardous properties.

Recent progress of phytogenic synthesis of ZnO, SnO2, and CeO2 nanomaterials

A critical investigation on the fabrication of metal oxide nanoparticles (NPs) such as ZnO, SnO₂, and CeO₂ NPs synthesized from green and phytogenic method using plants and various plant parts have been compiled. In this review, different plant extraction methods, synthesis methods, characterization techniques, effects of plant extract on the physical, chemical, and optical properties of green synthesized ZnO, SnO₂, and CeO₂ NPs also have been compiled and discussed. Effect of several parameters on the size, morphology, and optical band gap energy of metal oxide have been explored. Moreover, the role of solvents has been found important and discussed. Extract composition i.e. phytochemicals also found to affect the morphology and size of the synthesized ZnO, SnO₂, and CeO₂ NPs. It was found that, there is no universal extraction method that is ideal and extraction techniques is unique to the plant type, plant parts, and solvent used.

Leveraging Potential of Nanotherapeutics in Management of Diabetic Foot Ulcer

Diabetic foot ulcers (DFUs) are the most common complications associated with diabetes mellitus. DFUs are displayed as open sores or wounds located on the bottom of the foot as a secondary complication of diabetes mellitus (DM). DFUs are associated with significant morbidity and mortality and can subsequently lead to hospitalization and lower limb amputation if not recognized and treated on time. An immense challenge to conventional treatments is caused by the chronic nature of diabetic foot syndrome and it has led to the emergence of nanotechnology-based therapeutics. The greatest advantages of these nanotherapeutics are their unique biological, chemical, and physical properties. The present review highlights the augmentation of bacterial infections relating to delayed healing of DFUs and the potential of nanotherapeutics such as polymeric nanoparticles, metallic nanoparticles, siRNA-based nanoparticles, lipid nanoparticles, and nanofibers in accelerating wound healing in diabetic foot ulcers.

Zinc oxide and zinc oxide-based nanostructures: biogenic and phytogenic synthesis, properties and applications

Zinc oxide nanoparticles (ZnO NPs) are considered as very significant and essential material due to its multifunctional properties, stability, low cost and wide usage. Many green and biogenic approaches for ZnO NPs synthesis have been reported using various sources such as plants and microorganisms. Plants contain biomolecules that can act as capping, oxidizing and reducing agents that increase the rate of reaction and stabilizes the NPs. This review emphasizes and compiles different types of plants and parts of plant used for the synthesis of ZnO and its potential applications at one place. The influence of biogenic and phytogenic synthesized ZnO on its properties and possible mechanisms for its fabrication has been discussed. This review also highlights the potential applications and future prospects of phytogenic synthesized ZnO in the field of energy production and storage, sun light harvesting, environmental remediation, and biological applications.

Chemotaxonomy of the ethnic antidote Aristolochia indica for aristolochic acid content: Implications of anti-phospholipase activity and genotoxicity study

ETHNOPHARMACOLOGICAL RELEVANCE

Aristolochia indica L. (Aristolochiaceae) is a common medicinal plant described in many traditional medicine as well as in Ayurveda used against snakebites. Besides, the plant has also been reported traditionally against fever, rheumatic arthritis, madness, liver ailments, dyspepsia, oedema, leishmaniasis, leprosy, dysmenorrhoea, sexual diseases etc. The plant is known to contain its major bioactive constituent aristolochic acid (AA) known for its anti-snake venom, abortifacient, antimicrobial and antioxidant properties.

MATERIALS AND METHODS

This present work describes a validated, fast and reproducible high performance thin layer chromatography (HPTLC) method to estimate AA from the roots of 20 chemotypes of A. indica procured from 20 diverse geographical locations from the state of West Bengal, India. Further, an evidence-based approach was adopted to investigate the reported anti-venom activity of the aqueous extracts of the A. indica roots by assessing its phospholipase A₂ (PLA₂) inhibitory properties since PLA₂ is a major component of many snake-venoms. Finally, the cytotoxicity and genotoxicity of the aqueous root extract of the Purulia (AI 1) chemotype were assessed at various concentrations using Allium cepa root meristematic cells.

RESULTS

The highest amount of AA (7643.67 μg/g) was determined in the roots of A. indica chemotype collected from Purulia district followed by the chemotypes collected from Murshidabad, Jalpaiguri and Birbhum districts (7398.34, 7345.09 and 6809.97 μg/g respectively). This study not only determines AA in the plants to select pharmacologically elite chemotypes of A. indica, but it also identifies high AA producing A. indica for further domestication and propagation of the plants for pharmacological and industrial applications. The method was validated via analyzing inter-day and intra-day precision, repeatability, reproducibility, instrumental precision, limit of detection (LOD) and limit of quantification (LOQ) and specificity. Chemotypes with high AA content exhibited superior anti-PLA₂ activity by selectively inhibiting human-group PLA₂. Moreover, A. indica root extract significantly inhibited mitosis in Allium cepa root tips as a potent clastogen.

CONCLUSIONS

The present quick, reproducible and validated HPTLC method provides an easy tool to determine AA in natural A. indica plant populations as well as in food and dietary supplements, a potential antivenin at one hand and a possible cause of aristolochic acid nephropathy (AAN) at another. Besides, the cytotoxic and mitotoxic properties of the root extracts should be used with caution especially for oral administration.

Development of bactericidal spinel ferrite nanoparticles with effective biocompatibility for potential wound healing applications

The current study was devised to explore the antibacterial activity and underlying mechanism of spinel ferrite nanoparticles (NPs) along with their biocompatibility and wound healing potentials. In this regard, nickel ferrite and zinc/nickel ferrite NPs were synthesized via a modified co-precipitation method and were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy Energy-dispersive X-ray spectroscopy (EDX). The biocompatibility of the synthesized NPs with human dermal fibroblast (HDF) and red blood cells (RBCs) was assessed. The biocompatible concentrations of the NPs were used to investigate the antimicrobial activity against various pathogenic Gram-negative and Gram-positive bacteria. The mode of bactericidal action was also explored. In vitro scratch assay was performed to evaluate the wound healing potential of NPs. The SEM-EDX analysis showed that the average particles size of nickel ferrite and zinc/nickel ferrite were 49 and 46 nm, respectively, with appropriate elemental composition and homogenous distribution. The XRD pattern showed all the characteristic diffraction peaks of spinel ferrite NPs, which confirmed the synthesis of the pure phase cubic spinel structure. The biocompatible concentration of nickel ferrite and zinc/nickel ferrite NPs was found to be 250 and 125 μg ml-1, respectively. Both the NPs showed inhibition against all the selected strains in the concentration range of 50 to 1000 μg ml-1. Studies on the underlying antimicrobial mechanism revealed damage to the cell membrane, protein leakage, and intracellular reactive oxygen species production. The in vitro scratch assay confirmed the migration and proliferation of fibroblast with artificial wound shrinkage. This study shows that nickel ferrite and zinc/nickel ferrite NPs could be a strong candidate for antibacterial and wound healing nano-drugs.

The challenges and applications of nanotechnology against bacterial resistance

Bacterial resistance to the antibiotics develops rapidly and is increasingly serious health concern in the world. It is an insoluble topic due to the multiple resistant mechanisms. The overexpression of relative activities of the efflux pump has proven to be a frequent and important source of bacterial resistance. Efflux transporters in the membrane from the resistant bacteria could play a key role to inhibit the intracellular drug intake and impede the drug activities. However, nanoparticles (NPs), one of the most frequently used encapsulation materials, could increase the intracellular accumulation of the drug and inhibit the transporter activity effectively. The rational and successful application of nanotechnology is a key factor in overcoming bacterial resistance. Furthermore, nanoparticles such as metallic, carbon nanotubes and so on, may prevent the development of drug resistance and be associated with antibiotic agents, inhibiting biofilm formation or increasing the access into the target cell and exterminating the bacteria eventually. In the current study, the mechanisms of bacterial resistance are discussed and summarized. Additionally, the opportunities and challenges in the use of nanoparticles against bacterial resistance are also illuminated. At the same time, the use of nanoparticles to combat multidrug-resistant bacteria is also investigated by coupling natural antimicrobials or other alternatives. In short, we have provided a new perspective for the application of nanoparticles against multidrug-resistant bacteria.

Physics Comes to the Aid of Medicine-Clinically-Relevant Microorganisms through the Eyes of Atomic Force Microscope

Despite the hope that was raised with the implementation of antibiotics to the treatment of infections in medical practice, the initial enthusiasm has substantially faded due to increasing drug resistance in pathogenic microorganisms. Therefore, there is a need for novel analytical and diagnostic methods in order to extend our knowledge regarding the mode of action of the conventional and novel antimicrobial agents from a perspective of single microbial cells as well as their communities growing in infected sites, i.e., biofilms. In recent years, atomic force microscopy (AFM) has been mostly used to study different aspects of the pathophysiology of noninfectious conditions with attempts to characterize morphological and rheological properties of tissues, individual mammalian cells as well as their organelles and extracellular matrix, and cells’ mechanical changes upon exposure to different stimuli. At the same time, an ever-growing number of studies have demonstrated AFM as a valuable approach in studying microorganisms in regard to changes in their morphology and nanomechanical properties, e.g., stiffness in response to antimicrobial treatment or interaction with a substrate as well as the mechanisms behind their virulence. This review summarizes recent developments and the authors’ point of view on AFM-based evaluation of microorganisms’ response to applied antimicrobial treatment within a group of selected bacteria, fungi, and viruses. The AFM potential in development of modern diagnostic and therapeutic methods for combating of infections caused by drug-resistant bacterial strains is also discussed.

Nanotechnology-driven advances in the treatment of diabetic wounds

Diabetic foot ulcers (DFUs) are chronic severe complications of diabetes disease and remain a worldwide clinical challenge with social and economic consequences. Diabetic wounds can cause infection, amputation of lower extremities, and even death. Several factors including impaired angiogenesis, vascular insufficiency, and bacterial infections result in a delayed process of wound healing in diabetic patients. Treatment of wound infections using traditional antibiotics has become a critical status. Thus, finding new therapeutic strategies to manage diabetic wounds is urgently needed. Nanotechnology has emerged as an efficient approach for this purpose. This review aimed to summarize recent advances using nanotechnology for the treatment of diabetic wounds.

Biosynthesis of Metal Nanoparticles from Leaves of Ficus palmata and Evaluation of Their Anti-inflammatory and Anti-diabetic Activities

Metal nanoparticles (AgNPs and ZnONPs) were synthesized using a green methodology with the green leaves extract of the Bedu (Ficus palmata) tree as a reducing agent and the support of natural fibers. The synthesized AgNPs and ZnONPs were characterized by several techniques, including ultraviolet-visible spectral analysis, powder X-ray diffraction crystal analysis, scanning electron microscopy, EDAX, transmission electron microscopy, and Fourier transform infrared spectroscopy, which confirmed that the synthesized particles are in the nano range (1-100 nm), i.e., 30 nm for AgNPs with polydispersity and a spherical shape, whereas the average size of synthesized ZnONPs is 34 nm and they seem to exhibit a distorted spherical shape. The results of thermogravimetric analysis confirmed a weight loss of 18.02% for AgNPs under exothermic conditions due to the desorption of water, and ZnONPs show weight loss between 265 and 500 °C. Both synthesized MNPs are highly thermally stable. Anti-inflammatory and anti-diabetic studies of metal NPs have been evaluated. The AgNPs and ZnONPs of F. palmata leaves showed remarkably highly potent activity for respective strains. In vitro anti-diabetic activity was found for inhibition of α-amylases and α-glucosidases by synthesized silver nanoparticles.

Green Synthesis of ZnO Nanostructures Using Salvadora Persica Leaf Extract: Applications for Photocatalytic Degradation of Methylene Blue Dye

Various ZnO nanomaterials such as nanorods, nanoparticles, and nanosheets were synthesized using Salvadora persica leaf extract via the sol–gel method. The prepared nanomaterials possess a large number of nanocavities. The synthesized nanomaterials were characterized using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), UV-visible diffuse reflectance studies (UV-DRS), scanning electron microscopy (SEM), and high resolution transmission electron microscopy (HT-TEM), and these nanomaterials were used to test photocatalytic applications for the degradation of highly hazardous methylene blue dye. The degradation efficiency was higher for materials with nanorods and nanosheets with nanocavities; this was due to the presence of the nanocavities, which made the catalyst more sensitive to light absorption. This method offers a green synthesis of different nanomaterials in bulk quantity at low cost.

Preparation and Characterization of Zinc Oxide Nanoparticles Using Leaf Extract of Sambucus ebulus

Plants are one of the best sources to obtain a variety of natural surfactants in the field of green synthesizing material. Sambucus ebulus, which has unique natural properties, has been considered a promising material in traditional Asian medicine. In this context, zinc oxide nanoparticles (ZnO NPs) were prepared using S. ebulus leaf extract, and their physicochemical properties were investigated. X-ray diffraction (XRD) results revealed that the prepared ZnO NPs are highly crystalline, having a wurtzite crystal structure. The average crystallite size of prepared NPs was around 17 nm. Green synthesized NPs showed excellent absorption in the UV region as well as strong yellow-orange emission at room temperature. Prepared nanoparticles exhibited good antibacterial activity against various organisms and a passable photocatalytic degradation of methylene blue dye pollutants. The obtained results demonstrated that the biosynthesized ZnO NPs reveal interesting characteristics for various potential applications in the future.

Oscillating of physicochemical and biological properties of metal particles on their sonochemical treatment

Different metal particles are increasingly used to target bacteria as an alternative to antibiotics. Despite numerous data about treating bacterial infections, the utilization of metal particles in antibacterial coatings for implantable devices and medicinal materials promoting wound healing. The antibacterial mechanisms of nanoscale and microscale particles are poorly understood, but the currently accepted mechanisms include oxidative stress induction, metal ion release, and non-oxidative mechanisms. Thus, investigation of the antibacterial mechanisms of nanostructured metal particles is very important for the development of more effective antimicrobial materials. However, it is very difficult to develop a proper model for revealing the antibacterial mechanisms due to difficulty to choose a method that allows obtaining materials of various properties under approximately the same conditions. In this paper, we propose a green and feasible technique to create critical conditions for modification of zinc particles at highly non-equilibrium states. We demonstrate that the sonication process can be useful for fabrication the materials with oscillating physical, chemical and antibacterial properties. We believe this method besides medical applications can be also used in natural science basic research as an experimental tool for modelling the physical and chemical processes. After the sonication, the zinc particles exhibit a different surface morphology and amount of leached Zn²⁺ ions compared to initial ones. It has been revealed that oscillations of the Zn²⁺ ions concentration lead to oscillation the antibacterial properties. Thus, the properties of the materials can be easily altered by adjusting the ultrasound energy dissipated via varying the sonication.

Myristica fragrans bio-active ester functionalized ZnO nanoparticles exhibit antibacterial and antibiofilm activities in clinical isolates

We provide a novel one-step/one-pot bio-inspired method of synthesis for Myristica fragrans leaf ester (MFLE) capped‑zinc oxide nanoparticles (MFLE-ZnONPs). Antibacterial and antbiofilm efficacies of MFLE-ZnONPs were tested against the multi-drug resistant (MDR) Escherichia coli (E. coli-336), methicillin-resistant Staphylococcus aureus (MRSA-1) and methicillin-sensitive (MSSA-2) clinical isolates. Antibacterial screening using well diffusion assay revealed the cytotoxicity of MFLE-ZnONPs in the range of 500-2000 μg/ml. MFLE-ZnONPs significantly increased the zone of growth inhibition of E. coli-336 (17.0 ± 0.5 to 19.25 ± 1.0 mm), MSSA-2 (16.75 ± 0.8 to 19.0 ± 0.7 mm) and MRSA-1 (16.25 ± 1.0 to 18.25 ± 0.5 mm), respectively. The minimum inhibitory concentration (MIC) and minimum bactericidal concentrations (MBC) against E. coli-336, MRSA-1 and MSSA-2 were found to be 1500, 1000 and 500 μg/ml, and 2500, 2000 and 1500 μg/ml, respectively. A time and dose dependent reduction in the cell proliferation were also found at the respective MICs of tested strains. Scanning electron microscopy (SEM) of MFLE-ZnONPs-treated strains exhibited cellular damage via loss of native rod and coccoid shapes because of the formation of pits and cavities. E. coli-336 and MRSA-1 strains at their MICs (1500 and 1000 μg/ml) sharply reduced the biofilm production to 51% and 24%. The physico-chemical characterization via x-ray diffraction (XRD) ascertained the crystallinity and an average size of MFLE-ZnONPs as 48.32 ± 2.5 nm. Gas chromatography-mass spectroscopy (GC-MS) analysis of MFLE-ZnONPs unravelled the involvement of two bio-active esters (1) butyl 3-oxobut-2-yl ester and (2) α-monoolein) as surface capping/stabilizing agents. Fourier transform infrared (FTIR) analysis of MFLE and MFLE-ZnONPs showed the association of amines, alkanes, aldehydes, amides, carbonyl and amines functional groups in the corona formation. Overall, our data provide novel insights on the rapid development of eco-friendly, cost-effective bio-synthesis of MFLE-ZnONPs, showing their putative application as nano-antibiotics against MDR clinical isolates.

Potential bactericidal activity of S. nux-vomica-ZnO nanocomposite against multidrug-resistant bacterial pathogens and wound-healing properties

Multidrug resistance in bacterial strains has become the greatest challenge for healthcare professionals for treating non-healing ulcers such as diabetic foot infections (DFI). Plant-mediated synthesis of S. nux-vomica-ZnO nanocomposite appears as a potential new alternative therapeutic agent that might be capable of tackling antibiotic-resistant bacterial pathogens and for treating a non-healing ulcer. The aim of the study was to investigate the antibacterial potential of S. nux-vomica-ZnO nanocomposite biosynthesised from Strychnos nux-vomica against multidrug-resistant organisms (MDROs) from DFU, wound-healing properties, and cytotoxic effects. The antibacterial potential was assessed by minimum inhibitory concentration (MIC)/ minimum bactericidal concentration (MBC) assays, time-kill kinetics, protein-leakage, and flow cytometric analysis. The wound-healing properties were assessed by scratch assay on mouse L929 fibroblastic cell line to quantify cell migration towards the injured area. Cytotoxicity was assessed using 3-[4,5-dimethyl-2-thiazol-yl]-2,5-diphenyl- 2H-tetrazolium bromide (MTT) cellular viability assay on the L929 cell line and human embryonic kidney epithelial (HEK-293) cell line. Strychnos nux-vomica-ZnO nanocomposite at a size range of 10-12 nm exhibited significant bactericidal potency at a concentration of 100-200 μg/ml against MDR-Methicillin-resistant Staphylococcus aureus, MDR-Escherichia coli, MDR-Pseudomonas aeruginosa, MDR-Acinetobacter baumannii, and also against standard bacterial strains S. aureus ATCC 29213, E. coli ATCC 25922, P. aeruginosa ATCC 27853, E. faecalis ATCC 29212. S. nux-vomica-ZnO nanocomposite also exhibited wound-healing and reduced cytotoxic properties at the antimicrobially active concentrations. Our findings thus suggested remarkable bactericidal properties of S. nux-vomica-ZnO nanocomposite and can be further exploited towards for the development of an antibacterial agent against the threatening superbugs.

Self-Sterilizing and Regeneratable Microchip for the Precise Capture and Recovery of Viable Circulating Tumor Cells from Patients with Cancer

Cancer cells metastasize and are transported in the bloodstream, easily reaching any site in the body through the blood circulation. A method designed to assess the number of circulating tumor cells (CTCs) should be validated as a clinical tool for predicting the response to therapy and monitoring the disease progression in patients with cancer. Although CTCs are detectable in many cases, they remain unavailable for clinic usage because of their high testing cost, tedious operation, and poor clinical relevance. Herein, we developed a regeneratable microchip for isolating CTCs, which is available for robust cell heterogeneity assays on-site without the need for a sterile environment. The ivy-like hierarchical roughened zinc oxide (ZnO) nanograss interface was synthesized and directly integrated into the microfluidic devices and enables effective CTC capture and flexible, nontoxic CTC release during incubation in a mildly acidic solution, thus enabling cellular and molecular analyses. The microchip can be regenerated and recycled to capture CTCs with the remaining ZnO without affecting the efficiency, even after countless cycles of cell release. Moreover, microbial infection is avoided during its storage, distribution, and even in the open space usage, which ideally appeals to the demands of point-of-care (POC) and home testing and meets to the requirements for blood examinations in undeveloped or resource-limited settings. Furthermore, the findings generated using this platform based on the cocktail of antiepithelial cell adhesion molecule and antivimentin antibodies indicate that CTC capture was more precise and reasonable for patients with advanced cancer.

Synthesis and characterization of ZnO phytonanocomposite using Strychnos nux-vomica L. (Loganiaceae) and antimicrobial activity against multidrug-resistant bacterial strains from diabetic foot ulcer

Nanobiotechnology has been emerged as an efficient technology for the development of antimicrobial nanoparticles through an eco-friendly approach. In this study, green synthesized phytonanocomposite of ZnO from Strychnos nux-vomica leaf aqueous extract was characterized by X-ray diffraction analysis (XRD), UV–visible-spectroscopy, Photoluminescence spectroscopy (PL), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), High-resolution Transmission Electron Microscopy (HR-TEM), and Energy dispersive X-ray analysis (EDX). Antibacterial activity was investigated against multidrug-resistant bacteria (MDR) isolated from diabetic foot ulcers (DFUs), such as MDR–methicillin resistant Staphylococcus aureus (MRSA), MDR–Escherichia coli, MDR–Pseudomonas aeruginosa, MDR–Acinetobacter baumannii, as well as against standard bacterial strains, S. aureus ATCC 29213, E. coli ATCC 25922, P. aeruginosa ATCC 27853, and E. faecalis ATCC 29212 through disc diffusion assays on Muller Hinton Agar. The characterization studies revealed a size-controlled synthesis of quasi-spherical hexagonal wurtzite structured ZnO phytonanocomposite with an average size of 15.52 nm. Additionally, remarkable bactericidal activities against MDR clinical as well as ATCC bacterial strains were exhibited, with a maximum zone of inhibition of 22.33 ± 1.53 mm (against S. aureus ATCC 29213) and 22.33 ± 1.16 mm (MDR–MRSA) at a concentration of 400 µg/mL. This study thus established the possibility of developing antimicrobial ZnO nanocomposite of Strychnos nux-vomica leaf extract to combat developing drug resistance currently being experienced in health care facilities.