Human serum albumin directed formation of cadmium telluride quantum dots: Applications in biosensing, anti-bacterial activities and cell cytotoxicity measurements

Although cadmium-based quantum dots (QDs) are highly promising candidates for numerous biological applications, their intrinsic toxicity limits their pertinency in living systems. Surface functionalization of QDs with appropriate molecules could reduce the toxicity level. Herein, we have synthesized the smaller sized (1-5 nm) aqueous-compatible biogenic CdTe QDs using human serum albumin (HSA) as a surface passivating agent via a greener approach. HSA-functionalized CdTe QDs have been explored in multiple in vitro sensing and biological applications, namely, (1) sensing, (2) anti-bacterial and (3) anti-cancer properties. Using CdTe-HSA QDs as a fluorescence probe, a simple fluorometric method has been developed for highly sensitive and selective detection of blood marker bilirubin and hazardous Hg2+ ion with a limit of detection (LOD) of 3.38 and 0.53 ng/mL, respectively. CdTe-HSA QDs also acts as a sensor for standard antibiotics, tetracycline and rifampicin with LOD values of 41.34 and 114.99 ng/mL, respectively. Nano-sized biogenic CdTe-HSA QDs have shown promising anti-bacterial activities against both gram-negative, E. coli and gram-positive, E. faecalis strains confirming more effectiveness against E. faecalis strains. The treatment of human cervical cancer cell lines (HeLa cells) with the synthesized QDs reflected the proficient cytotoxic properties of QDs.

Green synthesis of silver nanoparticles employing hamdard joshanda extract: putative antimicrobial potential against gram positive and gram negative bacteria

The bio-mediated synthesis of nanoparticles offers a sustainable and eco-friendly approach. In the present study, silver nanoparticles (AgNPs) were synthesized using Joshanda extract, a commercially available herbal formulation derived from a traditional medicinal plant, as a reducing and stabilizing agent. The as-synthesized AgNPs were characterized using UV-Vis spectroscopy, dynamic light scattering (DLS), X-ray Diffraction (XRD) study, and Fourier-transform infrared (FTIR) analysis. UV-Vis spectroscopy exhibited a prominent absorption peak at 430 nm, confirming the formation of AgNPs. DLS analysis revealed the size distribution of the nanoparticles, ranging from 80 to 100 nm, and zeta potential measurements indicated a surface charge of - 14.4 mV. The XRD analysis provide evidence for the presence of a face-centered cubic structure within the silver nanoparticles. FTIR analysis further elucidated the interaction of bioactive compounds from the Joshanda extract with the AgNPs' surface. Strong peaks at 765-829 cm-1 indicated C-Cl stretching vibrations of alkyl halides, while the stretching of alkenes C=C was observed at 1641 cm-1. Moreover, the presence of alcohols and phenol (OH) groups was identified at 3448 cm-1, suggesting their involvement in nanoparticle stabilization. The antimicrobial potential of the synthesized AgNPs was evaluated against both gram-negative Pseudomonas aeruginosa and gram-positive Streptococcus mutans using zone of inhibition assays. The AgNPs exhibited remarkable inhibitory effects against both types of bacteria. Additionally, AgNPs-treated groups demonstrated a significant increase in reactive oxygen species (ROS) levels, indicating potential of as-synthesized AgNPs in disruption of the target microbial membranes. Furthermore, the as-synthesized AgNPs exhibited notable anti-biofilm properties by effectively hindering the development of mature biofilms. This study highlights the efficient green synthesis of AgNPs using Joshanda extract and also provides insights into their physico-chemical properties of as-synthesized nanoparticles. The demonstrated antimicrobial activity against both gram-negative and gram-positive bacteria, along with biofilm inhibition potential, underscores the promising applications of the as-synthesized AgNPs in the field of biomedical and environmental sciences. The study bridges traditional knowledge with contemporary nanotechnology, offering a novel avenue for the development of eco-friendly antimicrobial agents.

Bioactivity and mechanism of action of sanguinarine and its derivatives in the past 10 years

Sanguinarine is a quaternary ammonium benzophenanthine alkaloid found in traditional herbs such as Chelidonium, Corydalis, Sanguinarum, and Borovula. It has been proven to possess broad-spectrum biological activities, such as antitumor, anti-inflammatory, antiosteoporosis, neuroprotective, and antipathogenic microorganism activities. In this paper, recent progress on the biological activity and mechanism of action of sanguinarine and its derivatives over the past ten years is reviewed. The results showed that the biological activities of hematarginine and its derivatives are related mainly to the JAK/STAT, PI3K/Akt/mTOR, NF-κB, TGF-β, MAPK and Wnt/β-catenin signaling pathways. The limitations of using sanguinarine in clinical application are also discussed, and the research prospects of this subject are outlined. In general, sanguinarine, a natural medicine, has many pharmacological effects, but its toxicity and safety in clinical application still need to be further studied. This review provides useful information for the development of sanguinarine-based bioactive agents.

Synthesis and molecular docking study of α-aminophosphonates as potential multi-targeting antibacterial agents

Antibacterial compounds that reduce extracellular polymeric substances (EPS) are needed to avoid bacterial biofilms in water pipelines. Herein, green one-pot synthesis of α-aminophosphonates (α-Amps) [A-G] was achieved by using ionic liquid (IL) as a Lewis acid catalyst. The synthesized α-Amp analogues were tested against different bacteria such as Bacillus subtilis, Escherichia coli, and Pseudomonas aeruginosa. The representative [B] analogue showed an efficient antibacterial effect with MIC values of 3.13 μg/mL for E. coli, P. aeruginosa, and 6.25 μg/mL for B. subtilis. Additionally, a strong ability to eliminate the mature bacterial biofilm, with super-MIC values of 12.5 μg/mL for E. coli, P. aeruginosa, and 25 μg/mL for B. subtilis. Moreover, bacterial cell disruption by ROS formation was also tested, and the compound [B] revealed the highest ROS level compared to other compounds and the control, and efficiently destroyed the extracellular polymeric substances (EPS). The docking study confirmed strong interactions between [B] analogue and protein structures with a binding affinity of -6.65 kCal/mol for the lyase protein of gram-positive bacteria and -6.46 kCal/mol for DNA gyrase of gram-negative bacteria. The results showed that α-Amps moiety is a promising candidate for developing novel antibacterial and anti-biofilm agents for clean water supply.

Multi-functional bandage - bioactive glass/metal oxides/alginate composites based regenerative membrane facilitating re-epithelialization in diabetic wounds with sustained drug delivery and anti-bactericidal efficacy

Chronic wounds, especially diabetic, foot and pressure ulcers are a major health problem affecting >10 % of the world's populace. Calcium phosphate materials, particularly, bioactive glasses (BG), used as a potential material for hard and soft tissue repair. This study combines nanostructured 45S5 BG with titania (TiO2) and alumina (Al2O3) into a composite via simple sol-gel method. Prepared composites with alginate (Alg) formed a bioactive nanocomposite hydrogel membrane via freezing method. X-ray diffraction revealed formation of two phases such as Na1.8Ca1.1Si6O14 and β-Na2Ca4(PO4)2SiO4 in the silica network. Fourier transformed InfraRed spectroscopy confirmed the network formation and cross-linking between composite and alginate. <2 % hemolysis, optimal in vitro degradation and porosity was systematically evaluated up to 7 days, resulting in increasing membrane bioactivity. Significant cytocompatibility, cell migration and proliferation and a 3-4-fold increase in Collagen (Col) and Vascular Endothelial Growth Factor (VEGF) expression were obtained. Sustained delivery of 80 % Dox in 24 h and effective growth reduction of S. aureus and destruction of biofilm development against E. coli and S. aureus within 24 h. Anatomical fin regeneration, rapid re-epithelialization and wound closure were achieved within 14 days in both zebrafish and in streptozotocin (STZ) induced rat in vivo animal models with optimal blood glucose levels. Hence, the fabricated bioactive membrane can act as effective wound dressing material, for diabetic chronic infectious wounds.

Highly biocidal poly(vinyl alcohol)-hydantoin/starch hybrid gels: A "Trojan Horse" for Bacillus subtilis

HYPOTHESIS

Poly (vinyl alcohol) (PVA) cryogels can be functionalized with n-Halamines to confer biocidal features useful for their application as wound-dressing tools. Their efficacy can be boosted by stably embedding a polymeric bacterial food source (e.g., starch) in the gel matrix. The bioavailability of the food source lures bacteria inside the gel network via chemotactic mechanisms, promoting their contact with the biocidal functionalities and their consequent inactivation.

EXPERIMENTS

The synthesis of a novel hydantoin-functionalized PVA (H-PVA-hyd) is proposed. The newly synthesized H-PVA-hyd polymer was introduced in the formulation of H-PVA-based cryogels. To promote the cryogelation of the systems we exploited phase-separation mechanisms employing either a PVA carrying residual acetate groups (L-PVA) or starch as phase-segregating components. The permanence of the biocidal functionality after swelling was investigated via proton nuclear magnetic resonance (1H NMR) and Fourier transform infrared (FT-IR) microscopy. The activated H-PVA-hyd cryogels have been tested against bacteria with amylolytic activity (Bacillus subtilis) and the outcomes were analyzed by direct observation via confocal laser scanning microscopy (CLSM).

FINDINGS

The cryogels containing starch resulted in being the most effective (up to 90% bacterial killing), despite carrying a lower amount of hydantoin groups than their starch-free counterparts, suggesting that their improved efficacy relies on a "Trojan Horse" type of mechanism.

One Pot Synthesis and Biological Activity Studies of New Spirooxindoles

This article reports one-pot synthesis of ten novel spirooxindoles using 5-methyl-2-thiohydantoin, isatin derivatives, and malononitrile in good to high yields (65-90%.). The structures of the synthesized compounds were deduced by 1H NMR, 13C NMR, FT-IR, and Mass spectral data. The antibacterial activity of the compounds was evaluated against two Gram-positive bacteria (Staphylococcus aureus and Bacillus subtilis) and two Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa) based on the Kirby-Bauer method. According to the obtained data, the synthesized compounds show more activity against Gram-positive bacteria than Gram-negative bacteria. Also, the antioxidant activity of these compounds was measured using the DPPH radical scavenging test method, which showed good to excellent activity (59.65-94.03%). Among them, the chlorinated derivatives (4f-j) exhibited more antioxidant activity (84.85-94.03%) than the other compounds (4a-e) (56.65-74.4%) and even ascorbic acid as a standard antioxidant compound (82.3%).

Medulla Tetrapanacis water extract alleviates inflammation and infection by regulating macrophage polarization through MAPK signaling pathway

Medulla Tetrapanacis (MT) is a commonly used herb to promote lactation and manage mastitis in lactating mothers. However, its anti-inflammatory and anti-bacterial effects are currently unknown. We hypothesized that MT water extract possesses anti-inflammatory and anti-bacterial effects by modulating macrophage polarization to reduce the release of inflammatory mediators and phagocytosis via inactivation of MAPKs pathways. The chemical composition of the MT water extract was analyzed by UPLC-Orbitrap-mass spectrometry. The anti-inflammatory and anti-bacterial properties of the MT water extract were examined using LPS-stimulated inflammation and Staphylococcus aureus infection model in RAW 264.7 cells, respectively. The underlying mechanism of action of the MT water extract was also investigated. We identified eight compounds by UPLC-Orbitrap-mass spectrometry that are abundant within the MT water extract. MT water extract significantly suppressed LPS-induced nitric oxide, TNF-α and IL-6 secretion in RAW 264.7 cells which was accompanied by the promotion of macrophage polarization from pro-inflammatory towards anti-inflammatory phenotypes. MT water extract significantly suppressed the LPS-induced MAPK activation. Finally, MT water extract decreased the phagocytic capacity of the RAW 264.7 cells against S. aureus infection. MT water extract could suppress LPS-induced inflammation by promoting macrophages towards an anti-inflammatory phenotype. In addition, MT also inhibited the growth of S. aureus.

Revolutionary Pyrazole-based Aza-BODIPY: Harnessing Photothermal Power Against Cancer Cells and Bacteria

In the realm of cancer therapy and treatment of bacterial infection, photothermal therapy (PTT) stands out as a potential strategy. The challenge, however, is to create photothermal agents that can perform both imaging and PTT, a so-called theranostic agent. Photothermal agents that absorb and emit in the near-infrared region (750-900 nm) have recently received a lot of attention due to the extensive penetration of NIR light in biological tissues. In this study, we combined pyrazole with aza-BODIPY (PY-AZB) to develop a novel photothermal agent. PY-AZB demonstrated great photostability with a photothermal conversion efficiency (PCE) of up to 33 %. Additionally, PY-AZB can permeate cancer cells at a fast accumulation rate in less than 6 hours, according to the confocal images. Furthermore, in vitro photothermal therapy results showed that PY-AZB effectively eliminated cancer cells by up to 70 %. Interestingly, PY-AZB exhibited antibacterial activities against both gram-negative bacteria, Escherichia coli 780, and gram-positive bacteria, Staphylococcus aureus 1466. The results exhibit a satisfactory bactericidal effect against bacteria, with a killing efficiency of up to 100 % upon laser irradiation. As a result, PY-AZB may provide a viable option for photothermal treatment.

Comparative Evaluation of Antibacterial and Anti-Adherent Properties between Titanium Oxide, Silver Dioxide-Coated, and Conventional Orthodontic Wires Against Streptococcus Sanguis Causing Gingivitis

Objective

To compare the antibacterial and anti-adherent properties of conventional stainless steel (SS) orthodontic wires and surface-modified silver dioxide-coated and titanium oxide-coated SS orthodontic wires against Streptococcus sanguis causing gingivitis.

Materials and Methods

The study used 60 orthodontic SS wire specimens, organized into six groups of ten each. The control group had uncoated wires, and the experimental group featured wires coated with silver dioxide and titanium oxide. Surface modification was done using DC sputtering, and microbiological tests assessed the antibacterial and anti-adherent properties of the AgO2- and TiO2-coated wires.

Results

This study demonstrated the antibacterial effect against S. sanguis in orthodontic wires coated with the photocatalytic AgO2 and TiO2 compared to the uncoated wires. Also, this study demonstrated an anti-adherent effect in the AgO2- and TiO2-coated orthodontic wires. Moreover, the bacterial accumulation on orthodontic wires coated with AgO2 and TiO2 was lower compared to that on the uncoated wires.

Conclusion

During orthodontic treatment, the formation of dental plaque can be prevented by coating the surface of stainless-steel orthodontic wires with photocatalytic AgO2 and TiO2. Compared to silver dioxide, the titanium oxide-coated SS orthodontic wires showed better antibacterial and anti-adherent properties.

Banana fibre-chitosan-guar gum composite as an alternative wound healing material

Bio-composites, which can be obtained from the renewable natural resources, are fascinating material for use as sustainable biomaterials with essential properties like biodegradable, bio-compatibility as well cyto-compatibility etc. These properties are useful for bio-medical including wound healing applications. In this study, fibre obtained banana pseudo stem of banana plant, which is otherwise wasted, was used as a material along with chitosan and guar gum to fabricate a banana fibre-biopolymer composite patch. The physiochemical properties of the patches were examined using Fourier Transformed Infra-red spectrophotometer (FT-IR), tensile tester, Scanning Electron Microscope (SEM), contact angle tester, swelling and degradation studies. We further demonstrated that a herbal drug, Nirgundi could be loaded to the patch showed controlled its release at different pHs. The patch had good antibacterial property and supported proliferation of mouse fibroblast cells. The study thus indicates that banana fibre-chitosan-guar gum composite can be developed into an alternative wound healing material.

Unleashing the potential of tungsten disulfide: Current trends in biosensing and nanomedicine applications

The discovery of graphene ignites a great deal of interest in the research and advancement of two-dimensional (2D) layered materials. Within it, semiconducting transition metal dichalcogenides (TMDCs) are highly regarded due to their exceptional electrical and optoelectronic properties. Tungsten disulfide (WS2) is a TMDC with intriguing properties, such as biocompatibility, tunable bandgap, and outstanding photoelectric characteristics. These features make it a potential candidate for chemical sensing, biosensing, and tumor therapy. Despite the numerous reviews on the synthesis and application of TMDCs in the biomedical field, no comprehensive study still summarizes and unifies the research trends of WS2 from synthesis to biomedical applications. Therefore, this review aims to present a complete and thorough analysis of the current research trends in WS2 across several biomedical domains, including biosensing and nanomedicine, covering antibacterial applications, tissue engineering, drug delivery, and anticancer treatments. Finally, this review also discusses the potential opportunities and obstacles associated with WS2 to deliver a new outlook for advancing its progress in biomedical research.

Designing of bis-organosilanes as dual chemosensor for Sn(II) and Al(III) ions: Antibacterial activity and in silico molecular docking study

Here, in this article, we present the design and synthesis of 1,2,3-triazole allied Schiff base functionalized organosilanes 6(a-e) utilising single step approach. These compounds were further characterised using NMR (1H, 13C) and mass spectrometry. Furthermore, UV-Visible and fluorescence spectroscopy showed that compound 6a had a high selectivityto Sn(II) and Al(III) metal ions compared to other relevant metal ions with lowlimit of detection (LOD) values. Suppression of -C=N isomerization, constrained intramolecular charge transfer (ICT), and complexation with Sn(II)/Al(III) ions (Chelation Enhanced Fluorescence (CHEF)) results in probe 6a's enhanced turn on fluorescence toward the detection of Sn(II) and Al(III) ions. Probe 6a was a strong candidate for the detection of Sn(II) and Al(III) ions due to its selectivity, reversibility, and competitiveness. Since the detecting phenomenon can be reversed, the sensor 6a perfectly mimics the INHIBIT molecular logic gate. Also, computational study utilising DFT technique was used to shed light on the complexation mode of 6a with Sn(II) and Al(III) metal ions. The compound 6a's antibacterial activity has also been successfully tested against Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria. Additionally, the compound 6a was docked to the E. coli and S. aureus proteins, which exhibited excellent results with binding energies of -7.18 Kcal mol-1 and -7.05 Kcal mol-1, respectively. As both in-vitro and docking studies demonstrated anti-bacterial activity of the probe 6a, it may be anticipated that the probe has potential to serve as anti-bacterial drug in nearly future.

Evaluation of Yield, Chemical Profile, and Antimicrobial Activity of Teucrium polium L. Essential Oil Used in Iranian Folk Medicine

Teucrium polium L. is used to treat many diseases like abdominal pains, indigestion, colds, and reproductive system diseases in Iranian folk medicine. This study was designed to investigate the yield, chemical profile of essential oil, and antibacterial and antifungal activity of this species. The flowering aerial parts of T. polium were collected from the Margh region of Kashan, Iran. The essential oil of the plant was extracted and separated using the Clevenger apparatus and analyzed using gas chromatography-mass spectrometry (GC-MS). The antimicrobial activity of the essential oil against a variety of standard microbial strains was investigated with the Agar well-diffusion method and determination of the lowest growth inhibitory and lethal concentration (MIC and MBC). The results showed that the yield of T. polium essential oil (TPEO) was 0.5778%. Based on the results of GC-MS, 76 compounds (99.3%) were identified in the TPEO, of which α-pinene (9.67%), β-caryophyllene (8.07%), β-pinene (5.04%), nerolidol (4.94%), and oleic acid (4.57%) were the dominant components. The results of antimicrobial tests showed that the TPEO on Staphylococcus aureus created the largest zone of inhibition (~ 14.29 mm). The dominant inhibitory activity of this essential oil was against Gram-negative bacteria Escherichia coli (~ 9.00 mm), which was almost similar to rifampin (~ 11 mm). It seems that the predominance of terpenoid and acidic compounds of the essential oil is one of the possible factors of the anti-bacterial activity of this essential oil. Therefore, the TPEO may be a promising and potential strategy to inhibit some bacterial strains.

Preparation and characterization of ι-carrageenan nanocomposite hydrogels with dual anti-HPV and anti-bacterial activities

Sexually transmitted diseases (STDs) are usually caused by co-infections of bacteria and viruses. However, there is a lack of products that possess both antibacterial and antiviral activities without using chemical drugs. Here, we developed a carrageenan silver nanoparticle composite hydrogel (IC-AgNPs-Gel) based on the antiviral activity of iota carrageenan (IC) and the antibacterial effect of silver nanoparticles (AgNPs) to prevent STDs. IC-AgNPs-Gel showed excellent biocompatibility, hemostasis, antibacterial and antiviral effects. IC-AgNPs-Gel not only effectively prevented S. aureus, E. coli, P. aeruginosa, and C. albicans without using antibiotics, but also significantly inhibited human papilloma virus (HPV)-16 and HPV-6 without using chemotherapy drugs. Moreover, IC-AgNPs-Gel showed the effects of accelerating infected wound healing and reducing inflammation in a rat wound model infected with S. aureus. Therefore, the multifunctional hydrogel shows great potential application prospect in preventing STDs.

Surface defect engineered-Mg-based implants enable the dual functions of superhydrophobic and synergetic photothermal/chemodynamic therapy

Promoting metallic magnesium (Mg)-based implants to treat bone diseases in clinics, such as osteosarcoma and bacterial infection, remains a challenging topic. Herein, an iron hydroxide-based composite coating with a two-stage nanosheet-like structure was fabricated on Mg alloy, and this was followed by a thermal reduction treatment to break some of the surface Fe-OH bonds. The coating demonstrated three positive changes in properties due to the defects. First, the removal of -OH made the coating superhydrophobic, and it had self-cleaning and antifouling properties. This is beneficial for keeping the implants clean and for anti-corrosion before implantation into the human body. Furthermore, the superhydrophobicity could be removed by immersing the implant in a 75% ethanol solution, to further facilitate biological action during service. Second, the color of the coating changed from yellow to brown-black, leading to an increase in the light absorption, which resulted in an excellent photothermal effect. Third, the defects increased the Fe²⁺ content in the coating and highly improved peroxidase activity. Thus, the defect coating exhibited synergistic photothermal/chemodynamic therapeutic effects for bacteria and tumors. Moreover, the coating substantially enhanced the anti-corrosion and biocompatibility of the Mg alloys. Therefore, this study offers a novel multi-functional Mg-based implant for osteosarcoma therapy.

Heterocyclic pyrimidine derivatives as promising antibacterial agents

Antibiotic resistance is a growing public health concern. The quest to understand the underlying mechanisms of drug resistance needs to be accompanied by an expanded arsenal of drugs. This calls for the development of new compounds with anti-bacterial properties. The ease of functionalization of the pyrimidine core, to produce structurally distinct compound libraries, has made pyrimidine a privileged structure for identifying anti-bacterial hits. The activity of pyrimidine derivatives can be attributed to the various subunits linked with the main core, especially at C-2 or C-4 or C-6. Particularly, presence of NH2 attached to C-2 of the pyrimidine nucleus has been shown to enhance the anti-bacterial activity against pathogenic Gram-positive and Gram-negative bacteria. The diversity of synthetic routes used for the synthesis of such compounds, the reported biological activities, and a growing need to develop novel anti-bacterial agents warrant a review that presents recent reports on the synthesis and anti-bacterial activities of pyrimidine-containing compounds.

Exploring in vitro and in silico Biological Activities of Calligonum Comosum and Rumex Vesicarius: Implications on Anticancer and Antibacterial Therapeutics

Introduction

The adverse effects of clinically used anti-cancer medication and the rise in resistive micro-organisms have limited therapeutic options. Multiple anti-cancer drugs are derived from medicinal herbs which also have shown anti-bacterial effects. This study aimed to identify the optimal extraction solvent for detecting the cytotoxic and anti-bacterial effects of Calligonum comosum (C. Comosum) and Rumex vesicarius (R. Vesicarius) extracts. Additionally, the study aimed to identify active metabolites and assess their potential as future drug candidates for anti-cancer and anti-bacterial therapeutics.

Methods

Leaves from both plants were extracted using ethanol, ethyl acetate, chloroform, and water. The cytotoxic effects of the extracts were tested on liver, colon, and breast cancer cell lines. Apoptosis was assessed using High Content Imaging (HCI) and the ApoTox triplex Glo assay. The anti-bacterial effects were determined using agar-well diffusion. Liquid chromatography-mass spectrometry (LC-MS) was used to tentatively identify the secondary metabolites. In silico computational studies were conducted to determine the metabolites' mode of action, safety, and pharmacokinetic properties.

Results

The ethanolic extract of C. Comosum exhibited potent cytotoxicity on breast cancer cell lines, with IC50 values of 54.97 μg/mL and 58 μg/mL for KAIMRC2 and MDA-MB-231, respectively. It also induced apoptosis in colon and breast cancer cell lines. All tested extracts of C. Comosum and R. Vesicarius demonstrated anti-bacterial activity against Staphylococcus aureus and Escherichia coli. Seven active metabolites were identified, one of which is Kaempferol 3-O-Glucoside-7-O-Rhamnoside, which showed strong (predicted) anti-cancer activity. Kaempferol 3-O-Glucoside-7-O-Rhamnoside and Quercetin-3-O-Glucuronide also exhibited potential anti-bacterial effects on gram-positive and negative bacteria.

Conclusion

Ethanol extraction of C. Comosum solubilizes active metabolites with potential therapeutic applications in cancer treatment and bacterial infections. Kaempferol 3-O-Glucoside-7-O-Rhamnoside, in particular, shows promise as a dual therapeutic drug candidate for further research and development to improve its efficacy, safety, and pharmacokinetic profile.

ATP-triggered, selective superoxide radical generating oxidase-mimetic cerium oxide nanozyme exhibiting efficient antibacterial activity at physiological pH

Bacterial infections are considered as one of the major health threats to the global population. The advent of bacterial species with antibiotic resistance has attracted significant efforts to develop novel materials and strategies to effectively avoid the resistance with enhanced antibacterial potential. In this work, we have developed oxidase-mimetic cerium oxide nanoparticles (CeO2 NPs), which exhibit nanozyme activity at physiological pH in the presence of adenosine triphosphate (ATP). The oxidase-mimetic activity was confirmed to involve superoxide radicals using p-benzoquinone and dihydroethidium. Using indole propionic acid, ethanol, and terephthalic acid, it was confirmed that the oxidase-mimetic activity of CeO2 NPs with ATP does not involve the formation of hydroxyl radicals. CeO2 NPs with ATP produced a strong antibacterial activity against Staphylococcus aureus and Escherichia coli within 3 - 6 hrs. The bacterial cell morphology analysis suggested that superoxide radicals generated during the oxidase-mimetic activity of CeO2 NPs with ATP cause distortion of paired and tetrad arrangement (Staphylococcus aureus), loss of cytoplasmic content, damage, and pore formation in the cell wall (Escherichia coli) that led to the death of bacteria. Further, the live/dead assay also concludes the time-dependent death of bacterial cells with the highest death in the cell population exposed to CeO2 NPs and ATP. Thus, the antibacterial activity at physiological pH by superoxide radical generating oxidase-mimetic CeO2 NPs could be further extended to other pathogenic bacterial species.

Tailored biomedical materials for wound healing

Wound healing is a long-term, multi-stage biological process that mainly includes haemostatic, inflammatory, proliferative and tissue remodelling phases. Controlling infection and inflammation and promoting tissue regeneration can contribute well to wound healing. Smart biomaterials offer significant advantages in wound healing because of their ability to control wound healing in time and space. Understanding how biomaterials are designed for different stages of wound healing will facilitate future personalized material tailoring for different wounds, making them beneficial for wound therapy. This review summarizes the design approaches of biomaterials in the field of anti-inflammatory, antimicrobial and tissue regeneration, highlights the advanced precise control achieved by biomaterials in different stages of wound healing and outlines the clinical and practical applications of biomaterials in wound healing.

Poly(lactic acid)/cholecalciferol based composites for active food packaging application

Poly(lactic acid) (PLA) based sustainable composites incorporated with cholecalciferol (Vitamin D3) (CC) at different concentrations (1, 3, 5 and 10 wt%) were prepared using solvent casting method. Performance analysis of PLA/CC composite films in terms of food packaging properties like thermal, optical, oxygen barrier, mechanical, anti-bacterial as well as anti-oxidant effect is carried out. The PLA/CC-5 composite showed complete blockage of UV-B light at 320 nm, which is known to significantly induce the photo-chemical degradation of polymers. The incorporation of CC in the PLA matrix brought in improvement in mechanical and oxygen barrier properties. The PLA composite films showed effective antibacterial activity against food borne bacteria (S. aureus and E. coli), in addition to excellent antioxidant activity. All these important traits exhibited by PLA/CC composite films suggest its potential for food packaging application.

Quinoline derivatives volunteering against antimicrobial resistance: rational approaches, design strategies, structure activity relationship and mechanistic insights

Emergence of antimicrobial resistance has become a great threat to human species as there is shortage of development of new antimicrobial agents. So, its mandatary to combat AMR by initiating research and developing new novel antimicrobial agents. Among phytoconstituents, Quinoline (nitrogen containing heterocyclic) have played a wide role in providing new bioactive molecules. So, this review provides rational approaches, design strategies, structure activity relationship and mechanistic insights of newly developed quinoline derivatives as antimicrobial agents.

Selective preparation of crystalline or fibrous nano-cellulose carboxylate to fabricate an anti-bacterial hydrogel in co-operation with ZnO and recycled gelatin

Bio-polymeric based nano-composites and hydrogels are newsworthy nano-biomaterials. Herein, crystalline or fibrous nano-cellulose carboxylate (NCCC and NCCF) were selectively prepared via the controllable direct oxidative-hydrolysis of MC in alkaline NaClO₂ at 1:2 mol ratio, 90 °C, and 24 h for NCCC and at 1:1 mol ratio, 70 °C, and 20 h for NCCF. Characterization of NCCC and NCCF were performed by comparative Fourier transform infrared (FT-IR) spectroscopy, field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), thermal gravimetric analysis (TGA), and energy dispersive X-ray spectroscopy (EDS). Then, NCCC was cross-linked to the recycled gelatin (Gel) from the medicine capsules and the as-prepared nano-ZnO by maleic anhydride (MA) to give the novel hydrogel Gel/MA/NCCC/nano-ZnO. Nano-ZnO plays multi-roles in this hydrogel preparation, as either catalyst for the esterification of cellulose hydroxyls and amidation of gelatin amino groups or as the anti-bacterial part of hydrogel. The in vitro anti-bacterial activity results against the three gram-negative and gram-positive bacteria by well diffusion method confirmed Gel/MA/NCCC/nano-ZnO as an antibacterial agent with the activity order of P. aeruginosa > S. aureus > E. coli. The top anti-bacterial activity of this hydrogel against the gram-negative resistant bacteria of P. aeruginosa suggests its potential for biomedical applications.

Isolating Fistulifera pelliculosa from the northern Bohai Sea and analyzing biochemical composition, antibacterial and nutrient removal potential

The microalgae located near the estuary of the Liaohe River along the coast of Panjin have long been in an area with large fluctuations in salinity, temperature, and nutrients, and have high-quality alternatives for high-value metabolites. Three strains of microalgae were screened and the biomass of microalgae could be optimized 0.313-0.790 g L^-1 in 10 L bioreactor. The determination results of bioactive substances in these three microalgae showed that, the amount of fucoxanthin in the growth phase II (14 days) was maximum, at 5.354, 6.284 and 14.837 mg g^-1 respectively. The diatoxanthin of Dut-wj-J1 in growth phase III (21 days) could reach 5.158 mg g^-1. Dut-wj-J4 had the highest lipid production efficiency (9.45 mg L^-1 d^-1) followed by Dut-wj-J2 (8.49 mg L^-1 d^-1) and Dut-wj-J1 (8.18 mg L^-1 d^-1) respectively. These bioactive substances have inhibition zones of 7-13 mm against all four strains of bacteria ie., Acetobacter, Rhodococcus erythropolis, Escherichia coli and Bacillus subtilis Cohn respectively. In addition, these microalgae can play a potential role in nutrient enrichment in eutrophic seawater. The NO₃^- degradation rates of these three algae in the first 14 days were 75.0 %, 45.8 % and 100 % respectively, as well as the PO₄^- degradation rates in the first 7 days were 94.8 %, 100 % and 80.9 % respectively. This work manifests the plasticity of algae isolated from the Bohai Sea and provides useful insights for further joint production of bioactive substances.

Untargeted metabolomics description of propolis's in vitro antibacterial mechanisms against Clostridium perfringens

Propolis is a natural resinous substance that is collected by honeybees (Apis mellifera) with promising antibacterial effects. Here, we examined the antibacterial activity of Chinese propolis against Clostridium perfringens, a bacterial pathogen that threatens food safety and causes intestinal erosion. The inhibitory effects of the ethanolic extract of Chinese propolis (CPE) on human-associated C. perfringens strains were determined by using the circle of inhibition, the minimum inhibitory concentrations, and bactericidal concentrations. CPE also induced morphological elongation, bacterial cell wall damage, and intracellular material leakage in C. perfringens. Untargeted HPLC-qTOF-MS-based metabolomics analysis of the bacterial metabolic compounds revealed that propolis triggered glycerophospholipid metabolism, one carbon pool by folate, and d-glutamine and d-glutamate metabolism alterations in C. perfringens. Finally, caffeic acid phenethyl ester was identified as the key active ingredient in CPE. This study suggested the usage of propolis as an alternative to antibiotics in controlling C. perfringens.

Bergenia stracheyi extract-based hybrid hydrogels of biocompatible polymers with good adhesive, stretching, swelling, self-healing, antibacterial, and antioxidant properties

An ultra-stretchable, quickly self-healable, adhesive hydrogel with efficient anti-oxidant and anti-bacterial activities makes it potential wound dressing material, particularly in healing skin wounds. However, it is highly challenging to prepare such hydrogels with a facile and efficient material design. Given this, we opine the synthesis of medicinal plant Bergenia stracheyi extract-loaded hybrid hydrogels of biocompatible and biodegradable polymers like Gelatin, Hydroxypropyl cellulose, and Polyethylene glycol with acrylic acid via in situ free radical polymerization reaction. The selected plant extract is rich in phenols, flavonoids, and tannins and found to have important therapeutic benefits such as anti-ulcer, anti-Human Immunodeficiency Virus, anti-inflammatory, and burn wound healing effects. The polyphenolic compounds in the plant extract interacted strongly via hydrogen bonding with -OH, -NH₂, -COOH, and C-O-C groups of the macromolecules. The synthesized hydrogels were characterized by fourier transform infrared spectroscopy and rheology. The as-prepared hydrogels demonstrate ideal tissue adhesion, excellent stretchability, good mechanical strength, broad-band anti-bacterial capability, and efficient anti-oxidant properties, in addition to quick self-healing and moderate swelling properties. Thus, the aforementioned properties attract the potential use of these materials in the biomedical field.

In vitro evaluation of the potential use of snake-derived peptides in the treatment of respiratory infections using inhalation therapy: A proof of concept study

Inhalation therapy using nebulisers is an attractive non-invasive route for drug delivery, particularly for the treatment of lung infections with anti-inflammatory and anti-microbial compounds. This study evaluated the suitability of three snake-derived peptides (termed Sn1b, SnE1 and SnE1-F), which we have recently shown have potent anti-inflammatory and bacteriostatic activities, for nebulisation using a vibrating mesh nebuliser (VMN). The effect of nebulisation on peptide concentration, stability and function were assessed, prior to progression to aerodynamic particle size distribution, and in vitro drug delivery in simulated adult spontaneous breathing and mechanical ventilated patient models. When nebulised, all three peptides exhibited similar functions to their non-nebulised counterparts and were found to be respirable during simulated mechanical ventilation. Based on the assessment of the droplet distributions of nebulised peptides using a Next Generation Impactor (NGI) demonstrated that if administered in vivo each peptide would likely be delivered to the lower airways. These data suggest that nebulisation using a VMN is a viable means of anti-microbial / anti-inflammatory peptide delivery targeting microbial respiratory infections, and possibly even systemic infections.

A novel water-soluble chitosan grafted with nerol: Synthesis, characterization and biological activity

In order to improve the antibacterial activity of chitosan and change its solubility, a novel water-soluble chitosan (CS)-nerol (N) derivative (CS-N) was prepared via Schiff base reaction and grafting reaction. FT-IR, NMR, XRD, TGA and SEM were used to characterize the structure and physicochemical properties, and in vitro antibacterial, antioxidant, and cellular assays were used to test for bioactivity and safety. The results revealed that the C6 hydroxyl group of CS was substituted with N, with a degree of substitution of 38 % for CS-N. Furthermore, compared to CS, CS-N demonstrated superior antibacterial activity against Escherichia coli and Staphylococcus aureus, as well as significant DPPH and ABTS free radical scavenging activity. Most importantly, CS-N did not harm HaCaT cells. In conclusion, this study provides a promising strategy for the design of chitosan derivatives with significant potential for application in pharmaceutical, food and cosmetic applications.

In silico evaluation of usnic acid derivatives to discover potential antibacterial drugs against DNA gyrase B and DNA topoisomerase IV

Due to the rising increase in infectious diseases brought on by bacteria and anti-bacterial drug resistance, antibacterial therapy has become difficult. The majority of first-line antibiotics are no longer effective against numerous germs, posing a new hazard to global human health in the 21st century. Through the drug-likeness screening, 184 usnic acid derivatives were selected from an in-house database of 340 usnic acid compounds. The pharmacokinetics (ADMET) prediction produced fifteen hit compounds, of which the lead molecule was subsequently obtained through a molecular docking investigation. The lead compounds, labelled compound-277 and compound-276, respectively, with the substantial binding affinity towards the enzymes were obtained through further docking simulation on the DNA gyrase and DNA topoisomerase proteins. Additionally, molecular dynamic (MD) simulation was performed for 300 ns on the lead compounds in order to confirm the stability of the docked complexes and the binding pose discovered during docking tests. Due to their intriguing pharmacological characteristics, these substances may be promising therapeutic candidate for anti-bacterial medication.Communicated by Ramaswamy H. Sarma.

Stable superhydrophobic coating on Zr-based bulk metallic glass exhibiting excellent antibacterial property and cytocompatibility

A central challenge in the study of clinical medicine is to reduce the infection rate of implants without affecting cell adhesion and reproduction. For the first time, we prepared a robust and stable superhydrophobic Zn/pDop/SA coating on Zr₅₆Al₁₆Co₂₈ bulk metallic glass by electrodeposition that exhibits a maximum water contact angle of 158° and a sliding angle less than 1°. The growth of the coating micro-nano structure was controlled by changing the electrodeposition process parameters. The coating showed excellent antimicrobial adhesion properties in the environment to avoid bacteria adhesion and can transform from superhydrophobic to hydrophilic in body fluids to promote cell adhesion. The biodegradation of the Zn crystal structure was responsible for the hydrophobic transformation of the coating and the rough surface after biodegradation provided a point of adhesion for the cells. By designing a uniform crater structure on the substrate as an "armour" and co-depositing dopamine into the coating, the coating's wear resistance was greatly improved. The superhydrophobic coating can maintain stable superhydrophobicity in high temperature environment, air and UV irradiation. This study opens new horizons for the surface modification of bulk metallic glass and promotes its application in the medical field.

Injectable carboxymethyl chitosan-based hydrogel for simultaneous anti-tumor recurrence and anti-bacterial applications

The postoperative recurrence has adversely affected the treatment of tumors. Besides, the potential bacterial infection at the wound site may lead to a series of tissue necrosis. Here, we developed an injectable γ-polyglutamic acid/carboxymethyl chitosan/polydopamine hydrogel (PCP) for simultaneously reducing the postoperative infection and preventing the tumor recurrence. On the one hand, the aqueous solution of carboxymethyl chitosan oxidized the dopamine into polydopamine; on the other, the carboxymethyl chitosan was cross-linked with the activated γ-polyglutamic acid to form a hydrogel. After local implantation, the PCP hydrogel effectively killed tumor cells and bacteria under 808 nm laser irradiation. In addition, carboxymethyl chitosan rendered the hydrogel with anti-bacterial properties as well as anti-tumor efficiencies. The anti-tumor recurrence and anti-bacterial efficiencies of PCP hydrogel were proved on a tumor-removed mouse model and a Staphylococcus aureus-infected mouse model, respectively. Moreover, the hydrogel has the advantages of good biocompatibility and simple preparation, and thus has potential application prospects in the prevention of tumor recurrence and wound bacterial infection.

Chitosan -based nanoniosome for potential wound healing applications: Synergy of controlled drug release and antibacterial activity

This study aims to develop a niosomal platform which can delivery drugs such as tetracycline hydrochloride (TCH) to treat bacterial infections in wounds. To this end, chitosan (CS) was used to obtain a controlled drug release and at the same time antibacterial activity. By design of experiments the niosome encapsulated TCH (TCH-Nio) were optimized for their particle size and encapsulation efficiency, followed by analysis of the release profile of TCH and stability of TCH-Nio and TCH-Nio@CS. The antibacterial activity and cytotoxicity of the fabricated nanoparticles were investigated as well. The release rate of TCH from TCH-Nio@CS in all conditions is less than TCH-Nio. In addition, higher temperature increases the release rate of drug from these formulations. The size, polydispersity index, and encapsulation efficacy of TCH-Nio and TCH-Nio@CS were more stable in 4 °C compared to 25 °C. TCH, TCH-Nio, and TCH-Nio@CS had MIC values of 7.82, 3.91, and 1.95 μg/mL for Escherichia coli, 3.91, 1.95, and 0.98 μg/mL for Pseudomonas aeruginosa, and 1.96, 0.98, and 0.49 μg/mL for Staphylococcus aureus, respectively. Coating of chitosan on niosome encapsulated TCH (TCH-Nio@CS) led to a reduced burst release of TCH from niosome (TCH-Nio), and enabled 2-fold higher antibacterial and anti-biofilm activity against the tested bacterial pathogens E. coli, P. aeruginosa and S. aureus, compared to the uncoated TCH-Nio, and 4-folder higher than the TCH solution, suggesting the synergetic effect of niosome encapsulation and chitosan coating. Moreover, the formulated niosomes displayed no in vitro toxicity toward the human foreskin fibroblast cells (HFF). Both TCH-Nio and TCH-Nio@CS were found to down-regulate the expression of certain biofilm genes, i.e., csgA, ndvB, and icaA in the tested bacteria, which might partially explain the improved antibacterial activity compared to TCH. The obtained results demonstrated that TCH-Nio@CS is capable of controlled drug release, leading to high antibacterial efficacy. The established platform of TCH-Nio@CS enlighten a clinic potential toward the treatment of bacterial infections in skin wounds, dental implants and urinary catheter.

Sulfated polysaccharides as multi target molecules to fight COVID 19 and comorbidities

The majority of research to combat SARS-CoV-2 infection exploits the adaptive immune system, but innate immunity, the first line of defense against pathogenic microbes, is equally important in understanding and controlling infectious diseases. Various cellular mechanisms provide physiochemical barriers to microbe infection in mucosal membranes and epithelia, with extracellular polysaccharides, particularly sulfated polysaccharides, being among the most widespread and potent extracellular and secreted molecules blocking and deactivating bacteria, fungi, and viruses. New research reveals that a range of polysaccharides effectively inhibits COV-2 infection of mammalian cells in culture. This review provides an overview of sulfated polysaccharides nomenclature, its significance as immunomodulators, antioxidants, antitumors, anticoagulants, antibacterial, and as potent antivirals. It summarizes current research on various interactions of sulfated polysaccharide with a range of viruses, including SARS-CoV-2, and their application for potential treatments for COVID-19. These molecules interact with biochemical signaling in immune cell responses, by actions in oxidative reactions, cytokine signaling, receptor binding, and through antiviral and antibacterial toxicity. These properties provide the potential for the development of novel therapeutic treatments for SARS-CoV-2 and other infectious diseases from modified polysaccharides.

Chitosan-based multifunctional hydrogel for sequential wound inflammation elimination, infection inhibition, and wound healing

In this study, a composite hydrogel (QMPD hydrogel) composed of methacrylate anhydride (MA) grafted quaternary ammonium chitosan (QCS-MA), polyvinylpyrrolidone (PVP), and dopamine (DA) was designed for the sequential wound inflammation elimination, infection inhibition, and wound healing. The QMPD hydrogel formation was initiated by the ultraviolet light-triggered polymerization of QCS-MA. Furthermore, hydrogen bonds, electrostatic interactions, and "π-π" stacking between QCS-MA, PVP, and DA were involved in the hydrogel formation. In this hydrogel, the quaternary ammonium groups of quaternary ammonium chitosan and the photothermal conversion of polydopamine are capable of killing bacteria on wounds, which showed the bacteriostatic ratios of 85.6 % and 92.5 % toward Escherichia coli and Staphylococcus aureus, respectively. Moreover, the oxidation of DA sufficiently scavenged free radicals and introduced the QMPD hydrogel with good anti-oxidant and anti-inflammatory abilities. Together with the extracellular matrix-mimic tropical structure, the QMPD hydrogel significantly promoted the wound management of mice. Therefore, the QMPD hydrogel is expected to provide a new method for the design of wound healing dressings.

Sustainable synthesis of biogenic ZnO NPs for mitigation of emerging pollutants and pathogens

Groundwater pollution is mostly caused by overuse of fertilizers, pesticides, contemporary agricultural practices, anthropogenic activities, home waste disposal, and the rapid expansion of the chemical industry. Drinking tainted water on a regular basis can have detrimental consequences on human health as well on environment. Nanoparticles (NPs) based contaminants alleviation strategy found to be most efficient, cost-effective and reliable. In this study, ZnO NPs were synthesized via citrus limon leaves extract as a sustainable/cost-effective method. Diverse microscopic and spectroscopic studies confirmed the formation of spherical ZnO NPs with size range 15-25 nm. Reactive green-19 (RG-19) was degraded photocatalytically under direct solar irradiation (degradation efficiency ∼ 92%, rate constant 0.03 min ^-1, 80 min) in the presence of ZnO NPs. These ZnO NPs also demonstrated highly substantial antibacterial action against two pathogenic Gram-positive (Bacillus subtilis, zone of clearance: 8.6 mm) and Gram-negative (Escherichia coli, zone of clearance: 9.8 mm) bacteria. Thus, the present study demonstrates the effective/sustainable NPs based platform for water remediation.

Antimicrobial activity of synthesized graphene oxide-selenium nanocomposites: A mechanistic insight

Nanoparticles have recently gained interest as an anti-bacterial agent due to their large surface area/volume ratio and potential to compromise the integrity of bacterial cell membranes. Due to its versatility and anti-bacterial activity, graphene-based materials have drawn significant interest in biomedical applications. One of the greatest threats to life in the modern technological era is the pervasiveness of infectious diseases since bacteria cells are constantly updating themselves to resist antibiotics. In this presented study, GO-Se nanocomposite has been synthesized using polymer solution via a simple dispersion method. The structural and physicochemical properties of nanocomposite were investigated in detail. Staphylococcus aureus, Proteus vulgaris, and Bacillus subtilis bacterial strains were employed to study the anti-bacterial activity of GO-Se nanocomposite. The results show that the synthesized nanocomposites have good efficacy as an anti-bacterial agent. UV-vis spectroscopy, FTIR spectroscopy, HRTEM, XPS, and Raman spectroscopy were used to analyze the as-prepared GO and GO-Se nanocomposite.

Anti-bacterial and arsenic remediation insights in aqueous systems onto heterogeneous metal oxide (Cu0.52Al0.1Fe0.47O4)/rGO hybrid: an approach towards airborne microbial degradation

Copper-based ternary metal oxide (i.e., Cu0.52Al0.01Fe0.47O4) impregnated reduced graphene oxide nanohybrid is verified for microbial and arsenic treatment. Growth inhibition of colonies are observed around 99.99% (E. coli), and 99.83% (S. aureus) at 10-20 μg/mL of hybrid dosage, respectively. The inhibition rates for both the colonies are increased to 99.9998% at 80 μg/mL. TEM images have shown insight of cell-content/lipid leakage behavior after inoculating with the hybrid. The efficient hindrance towards microbial colony growth is attributed to better charge transfer, reactive oxygen species generation, and metal-ion release. Maximum arsenic sorption capacities are observed around 248 and 314 mg/g for As(III), and As(V), respectively (C_i ~ 500 ppm). Surface morphology studies onto arsenic adsorption are reported with atomic force microscope, and FT-IR/Raman analysis. A detailed discussion onto individual spectra of As 3d spectra confirmed the occurrence of redox transformation in arsenic species [As(III)]. The variation in the quantity (at. %) of oxygen functional groups in O1s spectra (i.e., M-O, M-OH, and -OH₂) onto the hybrid supported the ligand-exchange behavior. Cyclic voltammetry study in arsenic electrolytes (10 µM - 1 mM) provides the occurrence of various in-situ electrochemical reactions supporting the redox activity. A significant electromagnetic wave absorption characteristics of the present hybrid is proposed with plausible airborne antimicrobial-agent abilities.

Potential Antimicrobial and Antibiofilm Properties of Copper Oxide Nanoparticles: Time-Kill Kinetic Essay and Ultrastructure of Pathogenic Bacterial Cells

Mycosynthesis of nanoparticle (NP) production is a potential ecofriendly technology for large scale production. In the present study, copper oxide nanoparticles (CuONPs) have been synthesized from the live cell filtrate of the fungus Penicillium chrysogenum. The created CuONPs were characterized via several techniques, namely Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), transmission electron microscope (TEM), scanning electron microscope (SEM), and energy-dispersive X-ray spectroscopy (EDX). Furthermore, the biosynthesized CuONPs were performed against biofilm forming Klebsiella oxytoca ATCC 51,983, Escherichia coli ATCC 35,218, Staphylococcus aureus ATCC 25,923, and Bacillus cereus ATCC 11,778. The anti-bacterial activity result was shown with the zone of inhibition determined to be 14 ± 0.31 mm, 16 ± 0.53 mm, 11 ± 0.57 mm, and 10 ± 0.57 mm respectively. Klebsiella oxytoca and Escherichia coli were more susceptible to CuONPs with minimal inhibitory concentration (MIC) values 6.25 and 3.12 µg/mL, respectively, while for Staphylococcus aureus and Bacillus cereus, MIC value was 12.5 and 25 μg/mL, respectively. The minimum biofilm inhibition concentration (MBIC) result was more evident, that the CuONPs have excellent anti-biofilm activity at sub-MIC levels reducing biofilm formation by 49% and 59% against Klebsiella oxytoca and Escherichia coli, while the results indicated that the MBIC of CuONPs on Bacillus cereus and Staphylococcus aureus was higher than 200 μg/mL and 256 μg/mL, respectively, suggesting that these CuONPs could not inhibit mature formatted biofilm of Bacillus cereus and Staphylococcus aureus in vitro. Overall, all the results were clearly confirmed that the CuONPs have excellent anti-biofilm ability against Klebsiella oxytoca and Escherichia coli. The prepared CuONPs offer a smart approach for biomedical therapy of resistant microorganisms because of its promoted antimicrobial action, but only for specified purposes.

Natural cocktail of bioactive factors conjugated on nanofibrous dressing for improved wound healing

Any interference in the timely and orderly progression through all the phases of healing process can turn a minor injury into a chronic wound. Most of the wound dressings available in the market are moderately effective and have not shown satisfactory improvement in healing. Along with the appropriate wound management, it is imperative for a dressing to facilitate the wound repair process too. In the present research, we hypothesize to improve the wound healing process by applying cost effective natural cocktail of various bioactive factors. Bovine colostrum contains high levels of immunoglobulins, lactoferrin, hormones and cytokines which play significant role in wound healing. Hence, multifunctional colostrum conjugated PCL-PEG based nanofibrous dressings were developed and analyzed for their physicochemical properties and cellular responses. The dressings were also evaluated for cell migration, antioxidant, anti-inflammatory and anti-bacterial properties. In-vivo wound healing ability was validated on a rat wound model. Numerous growth factors present in the colostrum showed their role in stimulation of skin repair and regeneration by direct action on genetic material. Significantly less inflammation in colostrum treated wounds was observed due to anti-inflammatory properties of lactoferrin. Thus obtained results confirmed the suitability of these multifunctional colostrum conjugated nanofibrous dressings for improved wound healing.

Cichorium intybus bio-callus synthesized silver nanoparticles: A promising antioxidant, antibacterial and anticancer compound

Cichorium intybus, commonly called chicory, has been widely used as a coffee substitute. It display a wide range of natural compounds and medicinally uses in treatment of gastrointestinal disorders. This study synthesized silver nanoparticles (Ci-AgNPs) using C. intybus leaf-derived callus extract to evaluate phytochemical content, antibacterial, antioxidant and anti-proliferative activities against human breast cancer cells (MDA-MB231). The optimal shape, size and stability of Ci-AgNPs was confirmed using UV-visible spectrophotometry, FESEM, EDX, XRD, DLS, Zeta potential, FTIR and sp-ICP-MS studies. The antibacterial activity of Ci-AgNPs was assessed using disk diffusion method against Staphylococcus aureus and Escherichia coli, and they displayed distinct zones of inhibition. Colorimetric phytochemical analysis of Ci-AgNPs revealed their higher total phenolic (TP) and total flavonoid (TF) content. Ci-AgNPs also indicated a high level of antioxidant activity using FRAP and DPPH assays. The Ci-AgNPs were investigated for their anticancer activities on the cancerous MDA-MB231 cells viability and apoptosis using MTT and flow cytometry, respectively. Ci-AgNPs showed dose dependent cytotoxicity against MDA-MB231 cells with IC50 value of 187.6 μg/mL at 48 h through induction of apoptosis. The biocompatibility test showed that Ci-AgNPs induced neglectable cytotoxicity (lower than 3 %) toward human erythrocytes. This is the first study that reports the bio-callus mediated synthesis of silver nanoparticle using C. intybus callus extract which provided a promising anticancer activity against human breast cancer MDA-MB231 cells and therefore could be used as an alternative and interesting benign strategy for biosynthesis of silver nanoparticles useful in cancer therapy.

Anti-bacterial and Anti-biofilm Effects of Equol on Yersinia enterocolitica

Yersinia enterocolitica has clinical significance due to its etiological role in yersiniosis and gastroenteritis. This study was designed to assess anti-bacterial and anti-biofilm effects of equol on Y. enterocolitica via phenotypic and genetic analyses. To determine its anti-bacterial activity, minimum inhibitory concentrations (MICs) of equol against clinically isolated Y. enterocolitica strains were analyzed. Subsequently, it was confirmed that the sub-MIC90 value of equol could inhibit biofilm formation and reduce preformed biofilm. Furthermore, it was found that equol could reduce the expression of biofilm-related (hmsT) gene in Y. enterocolitica. This study also demonstrated that equol not only reduced levels of bacterial motility, but also decreased the expression of a motility-related (flhDC) gene in Y. enterocolitica. XTT [2,3-bis (2-metoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide] reduction analysis revealed that equol attenuated cellular metabolic activities in Y. enterocolitica biofilm. Additionally, changes in biomass and cell density in equol-treated biofilms were visualized using a confocal laser scanning microscope. In conclusion, this study suggests that equol is a potential anti-bacterial and anti-biofilm agent to treat Y. enterocolitica.

Carbonized lotus leaf/ZnO/Au for enhanced synergistic mechanical and photocatalytic bactericidal activity under visible light irradiation

Nowadays, bacterial resistance has continued to be a troublesome issue caused by the abuse of antibiotics, and it is the paramount difficulty in resolving the bacterial proliferation and infection. In this study, fresh lotus leaf was treated with Zn²⁺ followed by sintered and modification with gold nanoparticles through the photoreduction process sequentially, and thus a composite of micro/nanostructured carbonized lotus leaf/ZnO/Au (C-LL/ZnO/Au) was obtained to explore its bactericidal properties. C-LL/ZnO/Au retained the papillary structure of fresh lotus leaf and showed great mechanical bactericidal performance and photocatalytic sterilization. The antibacterial rate of mechanical sterilization for C-LL/ZnO/Au amount to 79.5% in 30 min, 4.7 times of fresh lotus leaf's figure under the same conditions. Furthermore, in C-LL/ZnO/Au, the introduction of gold nanoparticles heightened light absorbance through localized surface plasmon resonance (LSPR) effect and separation efficiency of photogenerated electron-hole pairs, which showed improved photocatalytic sterilization than that of carbonized lotus leaf/ZnO (C-LL/ZnO). Carbonized lotus leaf/ZnO/Au exhibited prominent photocatalytic and mechanical synergistic antibacterial performance against E. coli: all the bacteria were inactivated within 30 min under visible light. The approach presented here could be applied to a variety of biomass materials, which holds a promising application potential in biomedical, public health and other fields.

Two new neolignans and an indole alkaloid from the stems of Nauclea officinalis and their biological activities

A pair of new diastereoisomers neolignans (1-2) and a new alkaloid (7) were isolated from the stems of Nauclea officinalis: naucleaoxyneolignoside A (1), naucleaoxyneolignoside B (2), (2S,3S)-javaniside (7), together with nine known compounds, 2S-3,3-di-(4-hydroxy-3-methoxyphenyl)-propane-1,2-diol (3), threo-1,2-bis-(4-hydroxy-3-methoxyphenyl)-propane-1,3-diol (4), nauclefine (5), angustidine (6), naucleoxoside A (8), naucleoxoside B (9), angustoline (10), (3S,19S)-3,14-dihydroangustoline (11), and (3S,19R)-3,14-dihydroangustoline (12).The structures of 1, 2 and 7 were elucidated by extensive spectroscopic methods and the known compounds were identified by comparison of their data with those reported in the literature. The absolution configurations of 1, 2, 7,11 and 12 were confirmed by the quantum chemical CD calculation method. Compounds 1-9 showed weak to moderate inhibitory activity on nitric oxide (NO) production induced by lipopolysaccharide in mouse macrophage RAW 264.7 cells in vitro with IC₅₀ values comparable to that of dexamethasone. In addition, compounds 1-9 were evaluated for the antibacterial and cytotoxic effects, and the results revealed that these compounds showed no anti-bacterial activity, and compounds 3-6 showed modest cytotoxic activity.

Anti-bacterial monoclonal antibodies: next generation therapy against superbugs

Prior to the nineteenth century, infectious disease was one of the leading causes of death. Human life expectancy has roughly doubled over the past century as a result of the development of antibiotics and vaccines. However, the emergence of antibiotic-resistant superbugs brings new challenges. The side effects of broad-spectrum antibiotics, such as causing antimicrobial resistance and destroying the normal flora, often limit their applications. Furthermore, the development of new antibiotics has lagged far behind the emergence and spread of antibiotic resistance. On the other hand, the genome complexity of bacteria makes it difficult to create effective vaccines. Therefore, novel therapeutic agents in supplement to antibiotics and vaccines are urgently needed to improve the treatment of infections. In recent years, monoclonal antibodies (mAbs) have achieved remarkable clinical success in a variety of fields. In the treatment of infectious diseases, mAbs can play functions through multiple mechanisms, including toxins neutralization, virulence factors inhibition, complement-mediated killing activity, and opsonic phagocytosis. Toxins and bacterial surface components are good targets to generate antibodies against. The U.S. FDA has approved three monoclonal antibody drugs, and there are numerous candidates in the preclinical or clinical trial stages. This article reviews recent advances in the research and development of anti-bacterial monoclonal antibody drugs in order to provide a valuable reference for future studies in this area. KEY POINTS: • Novel drugs against antibiotic-resistant superbugs are urgently required • Monoclonal antibodies can treat bacterial infections through multiple mechanisms • There are many anti-bacterial monoclonal antibodies developed in recent years and some candidates have entered the preclinical or clinical stages of development.

One-step surface modification strategy with composition-tunable microgels: From bactericidal surface to cell-friendly surface

As modifiers for biomaterial surfaces, soft colloidal particles not only have good film-forming properties, but can also contribute to the function of the biomaterial via their chemical and biological properties. This general approach has proven effective for surface modification, but little is known about methods to control the properties of the colloidal particles to regulate film formation and biological function. In this work, we prepared poly (N-isopropylacrylamide) microgels (ZQP) containing both a zwitterionic component (Z) to provide anti-fouling functionality, and a quaternary ammonium salt (Q) to give bactericidal functionality. Fine-tuning of the Z and Q contents allowed the preparation of microgels over a range of particle size, size distribution, charge, and film-forming capability. The films showed anti-adhesion and contact-killing properties versus Escherichia coli (E. Coli), depending on the chemical composition. They also showed excellent cytocompatibility relative to L929 cells. A variety of microgel-coated substrates (silicon wafer, PDMS, PU, PVC) showed long-term anti-bacterial activity and resistance to chemical and mechanical treatments. It is concluded that this approach allows the preparation of effective bactericidal, cytocompatible surfaces. The properties can be fine-tuned by regulation of the microgel composition, and the method is applicable universally, i.e., independent of substrate.

Biomedical applications of L-alanine produced by Pediococcus acidilactici BD16 (alaD+)

L-alanine possesses extensive physiological functionality and tremendous pharmacological significance, therefore could be considered as potential ingredient for food, pharmaceutical, and personal care products. However, therapeutic properties of L-alanine still need to be addressed in detail to further strengthen its utilization as a viable ingredient for developing natural therapeutics with minimum side effects. Thus, the present study was aimed to explore the anticipated therapeutic potential of L-alanine, produced microbially using a lactic acid bacterial strain Pediococcus acidilactici BD16 (alaD⁺) expressing L-alanine dehydrogenase enzyme. The anticipated therapeutic potential of L-alanine was assessed in terms of anti-proliferative, anti-bacterial, and anti-urolithiatic properties. Anti-bacterial assays revealed that L-alanine successfully inhibited growth and in vitro proliferation of important human pathogens including Enterococcus faecalis, Escherichia coli, Klebsiella pneumonia, Staphylococcus aureus, Streptococcus mutans, and Vibrio cholerae in a concentration-dependent manner. Current investigation has also revealed its significant anti-proliferative potential against human lung adenocarcinoma (A549; IC₅₀ 7.32 μM) and mammary gland adenocarcinoma (MCF-7; IC₅₀ 8.81 μM) cells. The anti-urolithiatic potential of L-alanine was augmented over three different phases, viz., nucleation inhibition, aggregation inhibition, and oxalate depletion. Further, an in vitro cell culture-based kidney stone dissolution model using HEK293-T cells was also established to further strengthen its anti-urolithiatic potential. This is probably the first in vitro cell culture-based model which experimentally validates the immense therapeutic efficacy of L-alanine in treating urolithiasis disease. KEY POINTS: • Assessment of therapeutic potential of L-alanine produced by LAB. • L-alanine exhibited significant anti-proliferative and anti-bacterial activities. • L-alanine as potential anti-urolithiatic agent.

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

The integration of silver nanoparticles (Ag NPs) with mesoporous silica nanoparticles (MSNs) protects the former from aggregation and promotes the controlled release of silver ions, resulting in therapeutic significance on cancer and infection. The unique size, shape, pore structure and silver distribution of silver mesoporous silica nanoparticles (Ag-MSNs) embellish them with the potential to perform combined imaging and therapeutic actions via modulating optical and drug release properties. Here, we comprehensively review the recent progress in the fabrication and application of Ag-MSNs for combination therapies for cancer and infection. We first elaborate on the fabrication of star-shaped structure, core-shell structure, and Janus structure Ag-MSNs. We then highlight Ag-MSNs as a multifunctional nanoplatform to surface-enhanced Raman scattering-based detection, non-photo-based cancer theranostics and photo-based cancer theranostics. In addition, we detail Ag-MSNs for combined antibacterial therapy via drug delivery and phototherapy. Overall, we summarize the challenges and future perspectives of Ag-MSNs that make them promising for diagnosis and therapy of cancer and infection.

A review on synthetic account of 1,2,4-oxadiazoles as anti-infective agents

Most of the currently marketed drugs consist of heterocyclic scaffolds containing nitrogen and or oxygen as heteroatoms in their structures. Several research groups have synthesized diversely substituted 1,2,4-oxadiazoles as anti-infective agents having anti-bacterial, anti-viral, anti-leishmanial, etc. activities. For the first time, the present review article will provide the coverage of synthetic account of 1,2,4-oxadiazoles as anti-infective agents along with their potential for SAR, activity potential, promising target for mode of action. The efforts have been made to provide the chemical intuitions to the reader to design new chemical entity with potential of anti-infective activity. This review will mark the impact as the valuable, comprehensive and pioneered work along with the library of synthetic strategies for the organic and medicinal chemists for further refinement of 1,2,4-oxadiazole as anti-infective agents.

Cytokine expression and anti-microbial effectiveness of different calcium hydroxide dilutions: An In Vitro study

Aims

To determine the cytokine expression by human gingival fibroblasts in response to different calcium hydroxide (Ca(OH)₂) dilutions and test the effectiveness of these dilutions in root canal dentin infected with Enterococcus faecalis (E. faecalis).

Methods

UltraCal XS Ca(OH)₂ dilutions were prepared (60, 10, and 1 mg\mL) and co-cultured with gingival fibroblasts for 24 and 48 hours. Untreated cells were used as controls. Expressions of interleukin (IL-1β), tumour necrosis factor alpha (TNF-α), transforming growth factor beta (TGF-β), and IL-10 were analysed with real-time polymerase chain reaction (PCR). Root canals of extracted human teeth were inoculated with E. faecalis. After 21 days, canals were medicated with Ca(OH)₂ dilutions for 7 days. Samples were taken to determine bacterial reduction using quantitative PCR. Analysis of variance, Tukey post-test, and Wilcoxon matched pair test were used for statistics.

Results

IL-1β and TNF-α expressions of all Ca(OH)₂ dilutions were higher at 24 and 48 hours compared to the control. Similarly, all Ca(OH)₂ dilutions induced TGF-β expression at 24 hours compared to the control and continued to be higher in 60 mg/mL groups at 48 hours. In contrast, IL-10 was constitutively expressed by untreated cells in the control group and was down-regulated significantly by all Ca(OH)₂ dilutions at 24 and 48 hours. All dilutions demonstrated a significant E. faecalis reduction (P < 0.001) with no significant difference between dilution groups (P > 0.05).

Conclusions

All Ca(OH)₂ dilutions had a differential inflammatory effect on fibroblasts and had a down-regulation effect to IL-10. All dilutions tested were effective against E. faecalis, with 60 mg/mL having the highest bacterial reduction.

Evaluation of the properties and antibacterial activity of microchitosan film impregnated with Shirazi thyme (Zataria multiflora) and garlic (Allium sativum) essential oils

BACKGROUND

Recent research has shown that chitosan has good moisture-absorbing properties at the micro and nanoscale, and seems to be a good candidate for the production of biodegradable moisture-absorbing films.

AIMS

The aim of this study was to evaluate the properties and antibacterial activity of starch-based microchitosan (MCH) films impregnated with two essential oils (EOs).

METHODS

MCH films with varying thicknesses were made from cornstarch (6%), microchitosan (1%), glycerol (2.25%), and/or EOs (2%), and their characteristics, including swelling degree (SD), tensile strength (TS), and elongation at break (EB%), were examined. The film structures were confirmed by X-ray diffraction (XRD), scanning electron microscopy (SEM), and atomic force microscopy (AFM). To determine the antibacterial activity against Escherichia coli and Staphylococcus aureus, two EOs of Shirazi thyme, garlic, and a mixture of them were used in the experimentation.

RESULTS

The EB% and TS had a linear relationship with the thickness of samples and improved by increasing the thickness of films. The XRD pattern showed that the MCH films had an amorphous structure. SEM of the films showed a homogeneous dispersion of MCH in the starch matrix without any porosity. The AFM images showed a simultaneous increase in the thickness of the MCH films and surface roughness. The film was able to absorb water up to 15.78 times its weight in 48 h. The inhibition zone of films containing 2% thyme EO was 42.0 mm for S. aureus and 12.3 mm for E. coli (P<0.05).

CONCLUSION

MCH film containing Shirazi thyme can be described as a moisture-absorbing antibacterial pad and is a new idea for active food packaging to increase the shelf life of foods with fully degradable properties.