Antimicrobial and cytotoxic activity of green synthesis silver nanoparticles targeting skin and soft tissue infectious agents

Anti-Candida activity and biocompatibility of silver nanoparticles associated with denture glaze: a new approach to the management of denture stomatitis

The association of silver nanoparticles (AgNps) to sealant agent Palaseal® can be a promising alternative for complete denture wearers who may develop denture stomatitis (DS). The study aimed to evaluate the anti-Candida and biocompatible potential of silver nanoparticles synthesized by three routes associated with denture glaze to prevent and/or treat oral candidiasis. Surface acrylic resin specimens were treated with different associations of glaze with AgNps (VER+AgUV, VER+AgTurk and VER+AgGm). As controls, specimens were treated with glaze+nystatin (VER+Nyst), glaze only (VER) or submerged in PBS (PBS). Afterwards, Candida albicans biofilm was developed for 24 h, 15 d and 30 d. Subsequently, the biofilm was quantified by CFU/mL, XTT assay and confocal laser scanning microscopy. Fibroblasts were submitted to conditioned medium with the same associations for 24, 48 and 72 h and LIVE/DEAD® viability test was carried out. Regardless of the period, there was a significant reduction (p < 0.01) of viable fungal cells load, as well as inhibition of fungal metabolic activity, in specimens treated with glaze+AgNps associations, compared to VER and PBS. The anti-Candida effects of the associations were similar to the VER+Nyst group, with emphasis on VER+AgGm, which showed the highest percentage values of non-viable fungal cells maintained over time. The associations did not prove toxicity to fibroblasts. The AgNps exerted antimicrobial activity against C. albicans biofilms and are biocompatible. The most effective results were achieved with the association of glaze+silver nanoparticles synthesized by the green chemistry method (AgGm), proving to be an innovative alternative in the management of DS.

Enhancing Dental Alginate with Syzygium aromaticum, Zingiber officinale and Green Silver Nanoparticles: A Nature-Enhanced Approach for Superior Infection Control

OBJECTIVES

The study addresses the challenge of cross-infection in dentistry, focusing on improving disinfection protocols for dental hydrocolloid gel materials. This research aimed to incorporate chlorhexidine, natural plant extracts, and green-synthesized silver nanoparticles (AgNPs) into dental alginate to enhance safety and hygiene standards in dental practices.

METHODS

Conventional dental alginate served as the control, with experimental groups including alginate modified with 0.2% chlorhexidine (CHX-group) and alginate incorporating AgNPs synthesized from Syzygium aromaticum (SA) and Zingiber officinale (ZO) extracts (SA + AgNPs and ZO + AgNPs groups). Plant extracts were analyzed via GC/MS to confirm their composition. UV-visible spectroscopy, SEM, and EDX characterized the synthesized AgNPs. Antimicrobial efficacy against Candida albicans, Streptococcus mutans, and methicillin-resistant and methicillin-sensitive Staphylococcus aureus was evaluated using agar well diffusion assays. The dimensional accuracy of alginate impressions was assessed according to ISO 21563:2021 standards.

RESULTS

Chemical analysis of SA and ZO extracts identified 60 and 43 active compounds, respectively, supporting their use in AgNP synthesis. UV-visible spectroscopy, SEM, and EDX confirmed the formation of spherical AgNPs using SA and ZO extracts. Modified groups showed inhibitory activity against Streptococcus mutans and methicillin-resistant (MRSA) and methicillin-sensitive Staphylococcus aureus (MSSA), in contrast to the unmodified control. Both AgNP-modified groups demonstrated efficacy comparable to the CHX-group against MRSA and MSSA, with SA + AgNP showing superior performance against C. albicans. The dimensional accuracy of all groups was within clinically acceptable ranges as reported in the literature (0.027-0.083 mm).

DISCUSSION

CHX, silver nitrate, and green-synthesized AgNPs present promising options for developing self-disinfecting alginate impression materials. Utilizing plant extracts in AgNP synthesis offers a safe, efficient, and synergistic approach between metal ions and phytotherapeutic agents. This approach could potentially enhance disinfection efficacy without compromising material performance, improving dental safety and hygiene.

Synergistic Antimicrobial Activity of Biogenic Silver Nanoparticles and Acanthospermum australe Essential Oil against Skin Infection Pathogens

In response to the steady increase in antimicrobial-resistant strains, the World Health Organisation has emphasised the need to investigate new antimicrobial agents and alternative therapies that improve the spectrum of activity and reduce the dose required, thus improving safety. This study focused on the characterisation of Acanthospermum australe essential oil and green-synthesis silver nanoparticles (AgNP), evaluating their cytotoxicity in human cells, antimicrobial activity and synergistic effect against pathogens causing skin infections. The main components of the essential oil were germacrene A (24.07%), γ-cadinene (21.47%) and trans-caryophyllene (14.97%). Spherical AgNP with a diameter of 15 ± 3 nm were synthesised. The essential oil showed antimicrobial activity against dermatophytes and Malassezia globosa, while AgNP were found to be active against bacteria, yeasts and dermatophytes. Both compounds were found to be primarily non-cytotoxic at the concentrations required to inhibit microbial growth. Furthermore, the combined use of essential oil and AgNP showed a synergistic antimicrobial effect against dermatophytes and M. globosa. In conclusion, the results suggest that the combined use of bioactive compounds from natural sources, such as essential oil and biogenic AgNP, has the potential to improve antimicrobial efficacy against specific skin pathogens, particularly Microsporum canis, Nannizzia gypsea and M. globosa.

Antimicrobial and Antibiofilm Potential of Green-Synthesized Graphene-Silver Nanocomposite against Multidrug-Resistant Nosocomial Pathogens

Hospital-acquired infections (HAIs) pose a significant risk to global health, impacting millions of individuals globally. These infections have increased rates of morbidity and mortality due to the prevalence of widespread antimicrobial resistance (AMR). Graphene-based nanoparticles (GBNs) are known to possess extensive antimicrobial properties by inflicting damage to the cell membrane, suppressing virulence, and inhibiting microbial biofilms. Developing alternative therapies for HAIs and addressing AMR can be made easier and more affordable by combining nanoparticles with medicinal plants harboring antimicrobial properties. Hence, this study was undertaken to develop a novel graphene-silver nanocomposite via green synthesis using Trillium govanianum plant extract as a reducing agent. The resulting nanocomposite comprised silver nanoparticles embedded in graphene sheets. The antibacterial and antifungal properties of graphene-silver nanocomposites were investigated against several nosocomial pathogens, namely, Candida auris, Candida glabrata, Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, and Pseudomonas aeruginosa. The nanocomposite displayed broad-range antimicrobial potential against the test pathogens, with minimum inhibitory concentrations (MICs) ranging between 31.25 and 125.0 µg/mL, and biofilm inhibition up to 80-96%. Moreover, nanocomposite-functionalized urinary catheters demonstrated hemocompatibility towards sheep erythrocytes and imparted anti-fouling activity to the biomaterial, while also displaying biocompatibility towards HEK 293 cells. Collectively, this investigation highlights the possible application of green-synthesized GBNs as an effective alternative to conventional antibiotics for combating multidrug-resistant pathogens.

Biological activity of silver nanoparticles synthesized using viticultural waste

This research paper presents a novel approach to the green synthesis of silver nanoparticles (AgNPs) using viticultural waste, allowing to obtain NP dispersions with distinct properties and morphologies (monodisperse and polydisperse AgNPs, referred to as mAgNPs and pAgNPs) and to compare their biological activities. Our synthesis method utilized the ethanolic extract of Vitis vinifera pruning residues, resulting in the production of mAgNPs and pAgNPs with average sizes of 12 ± 5 nm and 19 ± 14 nm, respectively. Both these AgNPs preparations demonstrated an exceptional stability in terms of size distribution, which was maintained for one year. Antimicrobial testing revealed that both types of AgNPs inhibited either the growth of planktonic cells or the metabolic activity of biofilm sessile cells in Gram-negative bacteria and yeasts. No comparable activity was found towards Gram-positives. Overall, pAgNPs exhibited a higher antimicrobial efficacy compared to their monodisperse counterparts, suggesting that their size and shape may provide a broader spectrum of interactions with target cells. Both AgNP preparations showed no cytotoxicity towards a human keratinocyte cell line. Furthermore, in vivo tests using a silkworm animal model indicated the biocompatibility of the phytosynthesized AgNPs, as they had no adverse effects on insect larvae viability. These findings emphasize the potential of targeted AgNPs synthesized from viticultural waste as environmentally friendly antimicrobial agents with minimal impact on higher organisms.

Thermal and biological properties of novel sodium carboxymethylcellulose-PPFMA nanocomposites containing biosynthesized Ag-ZnO hybrid filler

The aim of this study was to produce new nanocomposites with antimicrobial, antioxidant and anticancer properties that can be used in biomedical research based on carboxymethyl cellulose (NaCMC) biopolymer. First, poly(2-oxo-2-(pentafluorophenoxy)ethyl-2-methylprop-2-enoate) (PPFMA) was synthesized and characterized by FTIR and NMR techniques. It was then blended with NaCMC by in situ/hydrothermal method to produce a semi-synthetic functional material. Changes in the FTIR data of the blend and the single Tg value from DSC confirmed the compatibility of the blend. To enhance the thermal and biological properties of the NaCMC-PPFMA blend, biosynthesized Ag-ZnONPs were hydrothermally incorporated into the blend at different weight ratios. The prepared materials were characterized by SEM, EDX, TEM, XRD and FTIR. The thermal stability of the materials was determined by thermogravimetric analysis (TGA), and glass transition temperatures (Tg) was determined by differential scanning calorimeter (DSC). The oxidant, antioxidant, antimicrobial, and cytotoxic properties of PPFMA, Ag-ZnONPs, PPFMA-NaCMC blend, and nanocomposites were investigated in detail. The total oxidant state (TOS) value of the NaCMC-PPFMA blend, which was 0.72 μmol equivalent H2O2/L, increased to 7.2-10.4 μmol equivalent H2O2/L with the addition of Ag-ZnONPs. Ag-ZnONPs decreased total antioxidant state (TAS) levels of the nanocomposites while increasing their oxidant activity. Therefore, an increase in the antimicrobial activity of the nanocomposites was observed. Adding Ag-ZnONPs to the NaCMC-PPFMA blend increased the thermal stability by 22 °C and the Tg value by 9 °C. Finally, the potential of Ag-ZnONPs containing nanocomposites in wound healing therapies was examined. The findings suggest that nanocomposites prepared by incorporating Ag-ZnONPs into the semi-synthetic NaCMC-PPFMA blend can be a source of bio-safe raw materials and can be used as potential wound healers.

The Promise of Metal-Doped Iron Oxide Nanoparticles as Antimicrobial Agent

Antibiotic resistance (AMR) is one of the pressing global public health concerns and projections indicate a potential 10 million fatalities by the year 2050. The decreasing effectiveness of commercially available antibiotics due to the drug resistance phenomenon has spurred research efforts to develop potent and safe antimicrobial agents. Iron oxide nanoparticles (IONPs), especially when doped with metals, have emerged as a promising avenue for combating microbial infections. Like IONPs, the antimicrobial activities of doped-IONPs are also linked to their surface charge, size, and shape. Doping metals on nanoparticles can alter the size and magnetic properties by reducing the energy band gap and combining electronic charges with spins. Furthermore, smaller metal-doped nanoparticles tend to exhibit enhanced antimicrobial activity due to their higher surface-to-volume ratio, facilitating greater interaction with bacterial cells. Moreover, metal doping can also lead to increased charge density in magnetic nanoparticles and thereby elevate reactive oxygen species (ROS) generation. These ROS play a vital role to disrupt bacterial cell membrane, proteins, or nucleic acids. In this review, we compared the antimicrobial activities of different doped-IONPs, elucidated their mechanism(s), and put forth opinions for improved biocompatibility.

Nanoparticles assisted intra and transdermic delivery of antifungal ointment: an updated review

This review paper highlights the trans-dermic delivery of nanoparticles (NPs) based antifungal ointments with the help of nanotechnology. It also describes the novel trans-dermal approach utilizing various nanoparticles which enables an efficient delivery to the target site. This current review gives an overview about past research and developments as well as the current nanoparticle-based ointments. This review also presents data regarding types, causes of infection, and different pathogens within their infection site. It also gives information about antifungal ointments with their activity and side effects of antifungal medicines. Additionally, this review also focuses on the future aspects of the topical administration of nanoparticle-based antifungal ointments. These nanoparticles can encapsulate multiple antifungal drugs as a combination therapy targeting different aspects of fungal infection. Nanoparticles can be designed in such a way that they can specifically target fungal cells and do not affect healthy cells. Nanoparticle based antifungal ointments exhibit outstanding potential to treat fungal diseases. As further research and advancements evolve in nanotechnology, we expect more development of nanoparticle-based antifungal formulations shortly. This paper discusses all the past and future applications, recent trends, and developments in the various field and also shows its bright prospective in the upcoming years.

Implementation of Silver Nanoparticles Green Synthesized with Leaf Extract of Coccinia grandis as Antimicrobial Agents Against Head and Neck Infection MDR Pathogens

BACKGROUND

Head and neck infections (HNI) associated with multidrug resistance (MDR) offer several health issues on a global scale due to inaccurate diagnosis.

OBJECTIVES

This study aimed to identify the bacteria and Candidal isolates and implement the silver nanoparticles green synthesized with leaf extract of Coccinia grandis (Cg-AgNPs) as a therapeutic approach against HNI pathogens.

METHODS

The Cg-AgNPs were characterized by the UV-visible spectrophotometer, FT-IR analysis, Zeta particle size, Zeta potential, and field emission scanning electron microscope (FESEM) analysis to validate the synthesis of nanoparticles. Additionally, the antimicrobial activity of Cg-AgNPs was presented by the zone of inhibition (ZOI), minimum inhibitory concentration (MIC), minimum bactericidal/fungicidal concentration (MBC/MFC), and antibiofilm assay. Moreover, the cell wall rupture assay was visualized on SEM for the morphological study of antimicrobial activities, and the in-vivo toxicity was performed in a swiss mice model to evaluate the impact of Cg-AgNPs on various biological parameters.

RESULTS

Different bacterial strains (Staphylococcus aureus, Acinetobacter baumannii, Klebsiella pneumoniae, and Pseudomonas aeruginosa) and Candida sp. (Candida albicans, Candida tropicalis, Candida orthopsilosis, and Candida glabrata) were identified. The MIC, MBC, and antibiofilm potential of Cg-AgNPs were found to be highest against A. baumannii: 1.25 μg/ml, 5 μg/ml, and 85.01±5.19% respectively. However, C. albicans and C. orthopsilosis revealed 23 mm and 21 mm of ZOI. Subsequently, the micromorphology of the cell wall rupture assay confirmed the efficacy of Cg-AgNPs, and no significant alterations were seen in biochemical and hematological parameters on the swiss mice model in both acute and subacute toxicity studies.

CONCLUSION

The green synthesized Cg-AgNPs have multifunctional activities like antibacterial, anticandidal, and antibiofilm activity with no toxicity and can be introduced against the HNI pathogens.

Green Synthesis of Silver Nanoparticles Using Jacobaea maritima and the Evaluation of Their Antibacterial and Anticancer Activities

Much attention has been gained on green silver nanoparticles (green-AgNPs) in the medical field due to their remarkable effects against multi-drug resistant (MDR) microorganisms and targeted cancer treatment. In the current study, we demonstrated a simple and environment-friendly (i.e., green) AgNP synthesis utilizing Jacobaea maritima aqueous leaf extract. This leaf is well-known for its medicinal properties and acts as a reducing and stabilizing agent. Nanoparticle preparation with the desired size and shape was controlled by distinct parameters; for instance, temperature, extract concentration of salt, and pH. The characterization of biosynthesized AgNPs was performed by the UV-spectroscopy technique, dynamic light scattering, scanning electron microscopy, X-ray diffraction, and Fourier-transform infrared. The successful formation of AgNPs was confirmed by a surface plasmon resonance at 422 nm using UV-visible spectroscopy and color change observation with a particle size of 37± 10 nm and a zeta potential of -10.9 ± 2.3 mV. SEM further confirmed the spherical size and shape of AgNPs with a size varying from 28 to 52 nm. Antibacterial activity of the AgNPs was confirmed against all Gram-negative and Gram-positive bacterial reference and MDR strains that were used in different inhibitory rates, and the highest effect was on the E-coli reference strain (MIC = 25 μg/mL). The anticancer study of AgNPs exhibited an IC50 of 1.37 μg/mL and 1.98 μg/mL against MCF-7 (breast cancer cells) and A549 (lung cancer cells), respectively. Therefore, this green synthesis of AgNPs could have a potential clinical application, and further in vivo study is required to assess their safety and efficacy.

Microalga Broths Synthesize Antibacterial and Non-Cytotoxic Silver Nanoparticles Showing Synergy with Antibiotics and Bacterial ROS Induction and Can Be Reused for Successive AgNP Batches

The era of increasing bacterial antibiotic resistance requires new approaches to fight infections. With this purpose, silver-based nanomaterials are a reality in some fields and promise new developments. We report the green synthesis of silver nanoparticles (AgNPs) using culture broths from a microalga. Broths from two media, with different compositions and pHs and sampled at two growth phases, produced eight AgNP types. Nanoparticles harvested after several synthesis periods showed differences in antibacterial activity and stability. Moreover, an evaluation of the broths for several consecutive syntheses did not find relevant kinetics or activity differences until the third round. Physicochemical characteristics of the AgNPs (core and hydrodynamic sizes, Z-potential, crystallinity, and corona composition) were determined, observing differences depending on the broths used. AgNPs showed good antibacterial activity at concentrations producing no or low cytotoxicity on cultured eukaryotic cells. All the AgNPs had high levels of synergy against Escherichia coli and Staphylococcus aureus with the classic antibiotics streptomycin and kanamycin, but with ampicillin only against S. aureus and tetracycline against E. coli. Differences in the synergy levels were also dependent on the types of AgNPs. We also found that, for some AgNPs, the killing of bacteria started before the massive accumulation of ROS.

Biological properties of experimental dental alginate modified for self-disinfection using green nanotechnology

OBJECTIVES

Disinfection of alginate impression materials is a mandatory step to prevent cross-infection in dental clinics. However, alginate disinfection methods are time-consuming and exert a negative impact on accuracy and mechanical properties. Thus, this study aimed to prepare disinfecting agents (CHX and AgNO3) and silver nanoparticles reduced by a natural plant extract to produce a self-disinfecting dental alginate.

METHODS

Conventional alginate impression material was used in this study. Silver nitrate (0.2% AgNO3 group) and chlorohexidine (0.2% CHX group) solutions were prepared using distilled water, and these solutions were later employed for alginate preparation. Moreover, a 90% aqueous plant extract was prepared from Boswellia sacra (BS) oleoresin and used to reduce silver nitrate to form silver nanoparticles that were incorporated in the dental alginate preparation (BS+AgNPs group). The plant extract was characterized by gas chromatography/mass spectrometry (GC/MS) analysis while green-synthesized silver nanoparticles (AgNPs) were characterized by UV-visible (UV-vis) spectroscopy and scanning electron microscopy (SEM). An agar disc diffusion assay was used to test the antimicrobial activity against Candida albicans, Streptococcus mutans, Escherichia coli, methicillin-resistant and susceptible Staphylococcus aureus strains, and Micrococcus luteus. Agar plates were incubated at 37 ± 1 °C for 24 h to allow microbial growth. Diameters of the circular inhibition zones formed around each specimen were measured digitally by using ImageJ software.

RESULTS

Chemical analysis of the plant extract revealed the presence of 41 volatile and semi-volatile active compounds. UV-Vis spectrophotometry, SEM, and EDX confirmed the formation of spherical silver nanoparticles using the BS extract. CHX, AgNO3, and the BS+AgNPs modified groups showed significantly larger inhibition zones than the control group against all tested strains. BS+AgNPs and CHX groups showed comparable efficacy against all tested strains except for Staphylococcus aureus, where the CHX-modified alginate had a significantly higher effect.

CONCLUSIONS AND CLINICAL RELEVANCE

CHX, silver nitrate, and biosynthesized silver nanoparticles could be promising inexpensive potential candidates for the preparation of a self-disinfecting alginate impression material without affecting its performance. Green synthesis of metal nanoparticles using Boswellia sacra extract could be a very safe, efficient, and nontoxic way with the additional advantage of a synergistic action between metal ions and the phytotherapeutic agents of the plant extract.

Exploring the Biomedical Applications of Biosynthesized Silver Nanoparticles Using Perilla frutescens Flavonoid Extract: Antibacterial, Antioxidant, and Cell Toxicity Properties against Colon Cancer Cells

The present study reports the biomimetic synthesis of silver nanoparticles (AgNPs) using a simple, cost effective and eco-friendly method. In this method, the flavonoid extract of Perilla frutescens (PFFE) was used as a bioreduction agent for the reduction of metallic silver into nanosilver, called P. frutescens flavonoid extract silver nanoparticles (PFFE-AgNPs). The Ultraviolet-Visible (UV-Vis) spectrum showed a characteristic absorption peak at 440 nm that confirmed the synthesis of PFFE-AgNPs. A Fourier transform infrared spectroscopic (FTIR) analysis of the PFFE-AgNPs revealed that flavonoids are involved in the bioreduction and capping processes. X-ray diffraction (XRD) and selected area electron diffraction (SAED) patterns confirmed the face-centered cubic (FCC) crystal structure of PFFE-AgNPs. A transmission electron microscopic (TEM) analysis indicated that the synthesized PFFE-AgNPs are 20 to 70 nm in size with spherical morphology and without any aggregation. Dynamic light scattering (DLS) studies showed that the average hydrodynamic size was 44 nm. A polydispersity index (PDI) of 0.321 denotes the monodispersed nature of PFFE-AgNPs. Further, a highly negative surface charge or zeta potential value (-30 mV) indicates the repulsion, non-aggregation, and stability of PFFE-AgNPs. PFFE-AgNPs showed cytotoxic effects against cancer cell lines, including human colon carcinoma (COLO205) and mouse melanoma (B16F10), with IC50 concentrations of 59.57 and 69.33 μg/mL, respectively. PFFE-AgNPs showed a significant inhibition of both Gram-positive (Listeria monocytogens and Enterococcus faecalis) and Gram-negative (Salmonella typhi and Acinetobacter baumannii) bacteria pathogens. PFFE-AgNPs exhibited in vitro antioxidant activity by quenching 1,1-diphenyl-2-picrylhydrazyl (DPPH) and hydrogen peroxide (H2O2) free radicals with IC50 values of 72.81 and 92.48 µg/mL, respectively. In this study, we also explained the plausible mechanisms of the biosynthesis, anticancer, and antibacterial effects of PFFE-AgNPs. Overall, these findings suggest that PFFE-AgNPs have potential as a multi-functional nanomaterial for biomedical applications, particularly in cancer therapy and infection control. However, it is important to note that further research is needed to determine the safety and efficacy of these nanoparticles in vivo, as well as to explore their potential in other areas of medicine.

Confronting antifungal resistance, tolerance, and persistence: Advances in drug target discovery and delivery systems

Human pathogenic fungi pose a serious threat to human health and safety. Unfortunately, the limited number of antifungal options is exacerbated by the continuous emergence of drug-resistant variants, leading to frequent drug treatment failures. Recent studies have also highlighted the clinical importance of other modes of fungal survival of antifungal treatment, including drug tolerance and persistence, pointing to the complexity of the fungal response to antifungal drugs. A lack of understanding of the fungal drug response has hampered the identification of new targets, the development of alternative antifungal strategies and the design of appropriate delivery systems. In this review we summarize recent advances in the study of antifungal resistance, tolerance and persistence, with an emphasis on promising drug targets and drug delivery systems that may yield important insights into the development of new or improved antifungal therapies against fungal infections.

Exploring the Antimicrobial, Anticancer, and Apoptosis Inducing Ability of Biofabricated Silver Nanoparticles Using Lagerstroemia speciosa Flower Buds against the Human Osteosarcoma (MG-63) Cell Line via Flow Cytometry

Biosynthesized nano-composites, such as silver nanoparticles (AgNPs), can be engineered to function as smart nano-biomedicine platforms for the detection and management of diverse ailments, such as infectious diseases and cancer. This study determined the eco-friendly fabrication of silver nanoparticles using Lagerstroemia speciosa (L.) Pers. flower buds and their efficacy against antimicrobial and anticancer activities. The UV-Visible spectrum was found at 413 nm showing a typical resonance spectrum for L. speciosa flower bud extract-assisted silver nanoparticles (Ls-AgNPs). Fourier transform infrared analysis revealed the presence of amines, halides, and halogen compounds, which were involved in the reduction and capping agent of AgNP formation. X-ray diffraction analysis revealed the face-centered cubic crystals of NPs. Energy dispersive X-ray verified the weight of 39.80% of silver (Ag), TEM analysis revealed the particles were spherical with a 10.27 to 62.5 nm range, and dynamic light scattering recorded the average particle size around 58.5 nm. Zeta potential showed a significant value at -39.4 mV, and finally, thermo-gravimetric analysis reported higher thermal stability of Ls-AgNPs. Further, the obtained Ls-AgNPs displayed good antimicrobial activity against clinical pathogens. In addition, a dose-dependent decrease in the anticancer activity by MTT assay on the osteosarcoma (MG-63) cell line showed a decrease in the cell viability with increasing in the concentration of Ls-AgNPs with an IC₅₀ value of 37.57 µg/mL. Subsequently, an apoptotic/necrosis study was conducted with the help of Annexin-V/PI assay, and the results indicated a significant rise in early and late apoptosis cell populations. Therefore, green synthesized Ls-AgNPs were found to have potent antimicrobial and anticancer properties making them fascinating choices for future bio-medical implementations.

Antibacterial and anticancer activities of green-synthesized silver nanoparticles using Photinia glabra fruit extract

Aims: We prepared Photinia glabra (PG) aqueous fruit extract, utilized it to synthesize silver nanoparticles (PG-Ag NPs) and evaluated the antibacterial and anticancer activities of the nanoparticles (NPs). Materials & methods: Silver nitrate aqueous solution was reduced to PG-Ag NPs using aqueous PG fruit extract. NP shape, size, composition and functionalization were determined using transmission electron microscopy, x-ray photoelectron spectroscopy, Fourier transform infrared and x-ray diffraction. Results & conclusions: PG-Ag NPs were spherical, approximately 39-77 nm-sized, functionalized surfaces with notable antibacterial activity against both Escherichia coli and Staphylococcus aureus, with an MIC <30 ug/ml and cytotoxicity toward esophageal cancer cells, with IC50 values less than 20 ug/ml. PG-Ag@rt NPs have been shown to be a potent antibacterial and anticancer agent, and their enriched particle surfaces can be conjugated with other compounds for multibiomedical applications.

Rotheca serrata Flower Bud Extract Mediated Bio-Friendly Preparation of Silver Nanoparticles: Their Characterizations, Anticancer, and Apoptosis Inducing Ability against Pancreatic Ductal Adenocarcinoma Cell Line

Over past decades, the green method of synthesizing metal nanoparticles has acquired more attentiveness by scientific consensus because of its industrial and biomedical applications. This study focuses on the anti-proliferative effectiveness of AgNPs synthesized from Rotheca serrata (L.) Steane & Mabb. flower bud extract against the PANC-1 cell line in vitro. Various analytical instruments were utilized to visualize the formation of RsFb-AgNPs, such as UV-Vis spectroscopy, FT-IR, SEM, EDS, TEM, XRD, Zeta potential, and DLS analysis. The biosynthesis of RsFb-AgNPs was observed by a change in color and UV-Vis spectroscopy (415 nm). The FT-IR spectra exhibited the existence of many functional groups. XRD confirmed the crystallinity of the AgNPs. Morphology and elemental mapping were assessed by SEM and EDS analysis. The TEM micrograph revealed spherical-shaped particles with sizes ranging from 12 to 40 nm. Zeta potential and DLS analysis were used to measure surface charge and particle size. Biological properties, including the antioxidant, antimicrobial, and anticancer properties of synthesized RsFb-AgNPs, exhibited dose-dependent activities. In DPPH assay, synthesized RsFb-AgNPs inhibited the scavenging of free radicals in a dose-dependent manner. In addition, the resultant RsFb-AgNPs displayed moderate antimicrobial activity against tested pathogens. Further, the anti-proliferative efficacy of biosynthesized RsFb-AgNPs was determined against the PANC-1 cell line using the MTT assay. The results revealed a dose-dependent decrease in viability of cancer cells with an IC50 value of 36.01 µg/mL. Flow cytometry was then used to confirm the apoptotic effects by double staining with annexin V/PI. In response to the pancreatic ductal adenocarinoma cell line, the results showed notable early and late apoptosis cell population percentages. In conclusion, the synthesized RsFb-AgNPs revealed a potential anticancer agent that can induce apoptosis in the PANC-1 cells.

Mesoporous silica SBA-15 composite for the delivery of amoxicillin against S. aureus skin infection

By subcutaneous injection of an amoxicillin-loaded nanocomposite, the skin bacterial infection of mice was well alleviated, and wound recovery was improved.

Antibacterial efficacy of silver nanoparticles (AgNPs) against metallo-β-lactamase and extended spectrum β-lactamase producing clinically procured isolates of Pseudomonas aeruginosa

Resistance to carbapenems is a global threat, especially in developing countries with limited health resources. Prevalence, antibiogram, PCR detection of antibiotic resistance genes, and potency of Silver Nanoparticles (AgNPs) against multidrug-resistant (MDR) Pseudomonas aeruginosa were studied. Kirby-Bauer disc method and PCR were used to study antibiogram and drug resistance genes respectively in 255 isolates of Pseudomonas aeruginosa obtained from a tertiary care hospital. Silver nitrate (AgNO₃) precursor salts were reacted with Aspergillus flavus culture filtrate to trigger the extracellular mycosynthesis of AgNPs. Mycosynthesis was first monitored regularly by visible ultraviolet spectroscopy that recorded AgNP peaks of approximately 400-470 nm. Confirmation by Transmission electron micrographs provided confirmation of AgNPs formed within a range of 5-30 nm. Individual and combined antibacterial activity of ten antibiotics and AgNPs was analyzed. Pearson correlation coefficients (r) were calculated for phenotypic and genotypic multidrug resistance. Data were evaluated using SPSS version 20. p-value < 0.05 was considered statistically significant. 61.5% were carbapenemase producers (p < 0.01). The recorded frequency of bla_IMP-1, bla_SHV, bla_VIM, bla_OXA, and bla_TEM were 13%, 32%, 15%, 21%, and 43%, respectively. The reducing order of antimicrobial activity of antibiotics and AgNPs was piperacillin/tazobactam + AgNPs (31 mm), cefoxitin + AgNPs (30 mm) > amikacin + AgNPs (25 mm) > aztreonam + AgNPs (23 mm) > meropenem + AgNPs (22 mm) > imipenem + AgNPs (20 mm) > gentamycin + AgNPs (17 mm) > ciprofloxacin + AgNPs (16 mm) > cefoperazone/sulbactam + AgNPs (14 mm) ≥ ceftazidime + AgNPs (14 mm). The conjugated effect of AgNPs plus antibiotics showed a 0.15-3.51 (average of 2.09) fold-area augmentation of antimicrobial activity. AgNPs conjugated with antibiotics effectively inhibited MDR Pseudomonas aeruginosa. To the best of our understanding, this is an inaugural report from Punjab Pakistan enlisting co-expression of Metallo-β-lactamases, extended-spectrum β-lactamases, and AmpC-β-lactamase plus activity of antibiotic-AgNPs.

Green Extracellular Synthesis of Silver Nanoparticles by Pseudomonas alloputida, Their Growth and Biofilm-Formation Inhibitory Activities and Synergic Behavior with Three Classical Antibiotics

Bacterial resistance to antibiotics is on the rise and hinders the fight against bacterial infections, which are expected to cause millions of deaths by 2050. New antibiotics are difficult to find, so alternatives are needed. One could be metal-based drugs, such as silver nanoparticles (AgNPs). In general, chemical methods for AgNPs' production are potentially toxic, and the physical ones expensive, while green approaches are not. In this paper, we present the green synthesis of AgNPs using two Pseudomonas alloputida B003 UAM culture broths, sampled from their exponential and stationary growth phases. AgNPs were physicochemically characterized by transmission electron microscopy (TEM), total reflection X-ray fluorescence (TXRF), infrared spectroscopy (FTIR), dynamic light scattering (DLS), and X-ray diffraction (XRD), showing differential characteristics depending on the synthesis method used. Antibacterial activity was tested in three assays, and we compared the growth and biofilm-formation inhibition of six test bacteria: Bacillus subtilis, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Staphylococcus aureus, and Staphylococcus epidermidis. We also monitored nanoparticles' synergic behavior through the growth inhibition of E. coli and S. aureus by three classical antibiotics: ampicillin, nalidixic acid, and streptomycin. The results indicate that very good AgNP activity was obtained with particularly low MICs for the three tested strains of P. aeruginosa. A good synergistic effect on streptomycin activity was observed for all the nanoparticles. For ampicillin, a synergic effect was detected only against S. aureus. ROS production was found to be related to the AgNPs' antibacterial activity.

Biogenic silver nanoparticles as antifungal agents

In recent years, an increase in multidrug-resistant fungal strains has been observed, which, together with the limited number of clinically available antifungal agents, highlights the need for the development of new antifungal agents. Due to the proven antifungal activity of silver nanoparticles (AgNPs), there is a growing interest in their use in the treatment of fungal infections. Nanoparticles are usually synthesised through a variety of physical and chemical processes that are costly and pollute the environment. For this reason, biogenic synthesis is emerging as an environmentally friendly technology and new strategies are increasingly based on the use of biogenic AgNPs as antifungal agents for clinical use. The aim of this review is to compare the antifungal activity of different biogenic AgNPs and to summarise the current knowledge on the mechanisms of action and resistance of fungi to AgNPs. Finally, a general analysis of the toxicity of biogenic AgNPs in human and veterinary medicine is performed.

Potential effects of noni (Morinda citrifolia L.) fruits extract against obsessive-compulsive disorder in marble burying and nestlet shredding behavior mice models

Obsessive-compulsive disorder (OCD) is a chronic and complex psychiatric disorder that usually includes both obsessions and compulsions. Morinda citrifolia L. (Noni) is a functional food and it is a well-known plant due to its potential therapeutic effects on human health in many disorders including neurological and neurodegenerative diseases. The purpose of this study was to evaluate the potential effect of M. citrifolia fruits extract (MCFE) against obsessive-compulsive disorder using the marble burying and nestlet shredding behavior mice models. In addition, brain neurotransmitters such as dopamine (DA), serotonin and noradrenaline (NA) were also assessed. Five mice were placed in each of the different groups, and the treatment was given to the animals for a period of 15 days. The marble burying test was evaluated for 30 min on days 1, 7, and 14 while the nestlet shredding test was evaluated for 60 min on days 2, 8, and 15. Treatments with MCFE (100 and 200 mg/kg, p.o.) significantly improved in both behavior tasks when compared to the control group. In addition, diazepam (2 mg/kg, i.p.) and fluoxetine (15 mg/kg, p.o.) were also significantly improved in both tasks when compared with the control mice. Further locomotor activity study revealed that MCFE and fluoxetine did not affect the locomotor functions when compared to vehicle treated mice. In contrast, diazepam significantly decreased locomotion when compared to the control group. The significant amelioration of biogenic amines were observed in the MCFE-treated animals with increased serotonin levels. The histopathology of the brain, liver, and kidney tissues after MCFE administration revealed normal morphological structure with no signs of toxicity or abnormalities. All these results together suggest that MCFE can be a potential drug candidate for the treatment of OCD. Future research should focus on theidentification and the anti-compulsive activity of the constituents from M. citrifolia.

Molecular mechanisms of the antibacterial activity of polyimide fibers in a skin-wound model with Gram-positive and Gram-negative bacterial infection in vivo

Recently, the need for antibacterial dressings has amplified because of the increase of traumatic injuries. However, there is still a lack of ideal, natural antibacterial dressings that show an efficient antibacterial property with no toxicity. Polyimide (PI) used as an implantable and flexible material has been recently reported as a mixture of particles showing more desirable antibacterial properties. However, we have identified a novel type of natural polyimide (PI) fiber that revealed antibacterial properties by itself for the first time. The PI fiber material is mainly composed of C, N, and O, and contains a small amount of Ca and Cl; the characteristic peaks of polyimide appear at 1774 cm-1, 1713 cm-1, 1370 cm-1, 1087 cm-1, and 722 cm-1. PI fibers displayed significant antibacterial activities against Escherichia coli (as a Gram-negative bacteria model) and methicillin-resistant Staphylococcus aureus (MRSA, as a Gram-positive bacteria model) according to the time-kill kinetics in vitro, and PI fibers damaged both bacterial cell walls directly. PI fibers efficiently ameliorated a local infection in vivo, inhibited the bacterial burden, decreased infiltrating macrophages, and accelerated wound healing in an E. coli- or MRSA-infected wound model. In conclusion, PI fibers used in the present study may act as potent antibacterial dressings protecting from MRSA or E. coli infections and as promising candidates for antimicrobial materials for trauma and surgical applications.

Antifungal Carvacrol Loaded Chitosan Nanoparticles

The increased prevalence and incidence of fungal infections, of which Candida albicans represents one of the most life-threatening organisms, is prompting the scientific community to develop novel antifungal molecules. Many essential oils components are attracting attention for their interesting antifungal activities. Given the chemical and physical characteristics of these compounds, the use of appropriate nanodelivery systems is becoming increasingly widespread. In this study, chitosan nanoparticles were prepared using an ionic gelation procedure and loaded with the phenolic monoterpene carvacrol. After a bioassay guided optimization, the best nanoparticle formulation was structurally characterized by means of different spectroscopic (UV, FTIR and DLS) and microscopy techniques (SEM) and described for their functional features (encapsulation efficiency, loading capacity and release kinetics). The antifungal activity of this formulation was assayed with different Candida spp., both in planktonic and biofilm forms. From these studies, it emerged that the carvacrol loaded nanoparticles were particularly active against planktonic forms and that the antibiofilm activity was highly dependent on the species tested, with the C. tropicalis and C. krusei strains resulting as the most susceptible.

The Emerging Role of Ionic Liquid-Based Approaches for Enhanced Skin Permeation of Bioactive Molecules: A Snapshot of the Past Couple of Years

Topical and transdermal delivery systems are of undeniable significance and ubiquity in healthcare, to facilitate the delivery of active pharmaceutical ingredients, respectively, onto or across the skin to enter systemic circulation. From ancient ointments and potions to modern micro/nanotechnological devices, a variety of approaches has been explored over the ages to improve the skin permeation of diverse medicines and cosmetics. Amongst the latest investigational dermal permeation enhancers, ionic liquids have been gaining momentum, and recent years have been prolific in this regard. As such, this review offers an outline of current methods for enhancing percutaneous permeation, highlighting selected reports where ionic liquid-based approaches have been investigated for this purpose. Future perspectives on use of ionic liquids for topical delivery of bioactive peptides are also presented.

In Vitro Antifungal Activity of Silver Nanoparticles Biosynthesized with Beech Bark Extract

Biosynthesis is a green method for the synthesis of silver nanoparticles (AgNPs). This study aimed to assess the antifungal activity of two silver nanoparticle solutions, synthesized using beech bark extract (BBE) and acetate and nitrate silver salts (AgNP Acetate BBE and AgNP Nitrate BBE), their influence on biofilm production, their potential synergistic effects with fluconazole, on different Candida spp., and their influence on virulence factors of C. albicans (germ tube production, gene expression for ALS3, SAP2, HSP70). Both the AgNP BBEs presented different minimum inhibitory concentrations for all the studied Candida spp., but biofilm production was inhibited only for C. albicans and C. guilliermondii. The growth rates of all the studied Candida spp. were inhibited in the presence of both AgNP BBEs, except for C. auris. Synergistic activity was observed for C. parapsilosis and C. guilliermondii, for different combinations of fluconazole with both the AgNP BBEs. The germ tube production of C. albicans was slightly inhibited by the AgNP BBEs. Only AgNP Acetate BBE was able to down-regulate the expression of SAP2. Overall, we can conclude that, even if more studies are necessary, AgNPs synthesized with beech bark extract might be an interesting alternative to classic antifungal treatments.