Green synthesis of Ag and Cu-doped Bismuth oxide nanoparticles: Revealing synergistic antimicrobial and selective cytotoxic potentials for biomedical advancements

BACKGROUND

Nanotechnology has emerged as a transformative realm of exploration across diverse scientific domains. A particular focus lies on metal oxide nanoparticles, which boast distinctive physicochemical attributes on the nanoscale. Of note, green synthesis has emerged as a promising avenue, leveraging plant extracts as both reduction and capping agents. This approach offers environmentally friendly and cost-effective avenues for generating monodispersed nanoparticles with precise morphologies.

METHODS

In this investigation, we embarked on the synthesis of Bismuth oxide nanoparticles, both in their pure form and doped with silver (Ag) and copper (Cu). This synthesis harnessed the potential of Biebersteinia multifida extract as a versatile reducing agent. To comprehensively characterize the synthesized nanoparticles, a suite of analytical techniques was employed, including energy-dispersive X-ray spectroscopy, field-emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), UV-Vis spectroscopy, and Raman spectroscopy.

RESULTS

The synthesized nanoparticles underwent a rigorous assessment. Their antibacterial attributes were probed, revealing a pronounced enhancement in antibiofilm activity against Pseudomonas aeruginosa and Staphylococcus aureus bacteria upon metal nanoparticle doping. Furthermore, their potential for combating cancer was scrutinized, with the nanoparticles exhibiting selective cytotoxicity towards cancer cells, U87, compared to normal 3T3 cells. Notably, among the doped nanoparticles, Cu-doped variants demonstrated the highest potency, further underscoring their promising potential.

CONCLUSION

In conclusion, the present study underscores the efficacy of green synthesized Bismuth oxide nanoparticles, particularly those doped with Ag and Cu, in augmenting antibacterial efficacy, bolstering biofilm inhibition, and manifesting selective cytotoxicity against cancer cells. These findings portend a promising trajectory for these nanoparticles in the spheres of biomedicine and therapeutics. As we look ahead, a deeper elucidation of their mechanistic underpinnings and in vivo investigations are essential to fully unlock their potential for forthcoming biomedical applications.

Advances of liposomal mediated nanocarriers for the treatment of dermatophyte infections

Due to the adverse effects associated with long-term administration of antifungal drugs used for treating dermatophytic lesions like tinea unguium, there is a critical need for novel antifungal therapies that exhibit improved absorption and minimal adverse effects. Nanoformulations offer a promising solution in this regard. Topical formulations may penetrate the upper layers of the skin, such as the stratum corneum, and release an appropriate amount of drugs in therapeutic quantities. Liposomes, particularly nanosized ones, used as topical medication delivery systems for the skin, may have various roles depending on their size, lipid and cholesterol content, ingredient percentage, lamellarity, and surface charge. Liposomes can enhance permeability through the stratum corneum, minimize systemic effects due to their localizing properties, and overcome various challenges in cutaneous drug delivery. Antifungal medications encapsulated in liposomes, including fluconazole, ketoconazole, croconazole, econazole, terbinafine hydrochloride, tolnaftate, and miconazole, have demonstrated improved skin penetration and localization. This review discusses the traditional treatment of dermatophytes and liposomal formulations. Additionally, promising liposomal formulations that may soon be available in the market are introduced. The objective of this review is to provide a comprehensive understanding of dermatophyte infections and the role of liposomes in enhancing treatment.

In vitro antifungal potency of the moronecidin-like peptide against Candida albicans, Candida glabrata, and Candida tropicalis

Background and Objectives

The aim of this study was to investigate the in vitro antifungal potency of the moronecidin-like peptide against Candida albicans, Candida glabrata, and Candida tropicalis.

Materials and Methods

To evaluate the antifungal effect of moronecidin-like peptide, the protocol presented in CLSI M27-A3 and CLSI M27-S4 was used and the minimum inhibitory concentration was determined.

Results

The minimum inhibitory effect of moronecidin-like peptide composition was 8 µg/ml for Candida tropicalis and Candida albicans and 32 µg/ml for Candida glabrata. The MIC of nystatin was determined to be 1.25 µg/ml for Candida glabrata and Candida albicans and 0.625 µg/ml for Candida tropicalis strains. The MFC composition of the moronecidin-like peptide was determined for Candida tropicalis and Candida albicans strains 8 µg/ml and for Candida glabrata strain 64 µg/ml. The results of cytotoxicity and hemolysis of the moronecidin peptide test on macrophage showed that moronecidin peptide has no cytotoxicity and toxicity properties.

Conclusion

According to the results of the present study, the moronecidin-like peptide could be a new strategy in the treatment of infections caused by Candida strains. The discovery of the exact mechanism of which requires extensive clinical studies in this field.

Fungal keratitis in Iran: Risk factors, clinical features, and mycological profile

Introduction

This study was intended to investigate the clinical features and predisposing factors of fungal keratitis (FK), as well as molecular identification and antifungal susceptibility of causative agents in Tehran, Iran.

Methods

This cross-sectional study was carried out from April 2019 to May 2021. All fungi isolates were identified using conventional methods and were confirmed by DNA-PCR-based molecular assays. Matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) was used to identify yeast species. Minimum inhibitory concentrations (MIC) of eight antifungal agents were assessed according to the European Committee on Antimicrobial Susceptibility Testing (EUCAST) microbroth dilution reference method.

Results

Fungal etiology was confirmed in 86 (7.23%) of 1189 corneal ulcers. A significant predisposing factor for FK was ocular trauma caused by plant materials. Therapeutic penetrating keratoplasty (PKP) was required in 60.4% of cases. The predominant fungal species isolated was Fusarium spp. (39.5%) followed by Aspergillus spp. (32.5%) and Candida spp. (16.2%).

Discussion

The MIC results indicate that amphotericin B may be appropriate for treating FK caused by Fusarium species. FK caused by Candida spp. can be treated with flucytosine, voriconazole, posaconazole, miconazole, and caspofungin. In developing countries such as Iran, corneal infection due to filamentous fungi is a common cause of corneal damage. In this region, fungal keratitis is observed primarily within the context of agricultural activity and subsequent ocular trauma. Fungal keratitis can be managed better with understanding the "local" etiologies and antifungal susceptibility patterns.

Identification of Candida spp. isolated from oral mucosa in patients with leukemias and lymphomas in Iran

Background and Objectives: Oral candidiasis is a serious problem for immunocompromised patients, especially patients with hematological malignancies. After becoming a systemic candidiasis it is difficult to diagnose, control and treat in indi- viduals with hematological malignancies. The aim of this study was to diagnose candidiasis in the oral mucosa of patients with leukemias and lymphomas in a timely manner in order to prevent their progression to systemic candidiasis. Materials and Methods: In this cross sectional study, 50 clinical samples were collected from the mouth of patients with hematological malignancies undergoing chemotherapy from the oncology units of teaching hospitals in Kerman, Iran. Pa- tients were from Kerman, Sistan-Baluchestan and Hormozgan in south-eastern Iran. Sampling was restricted to patients with diagnosed acute lymphoid leukemia (ALL); acute myeloid leukemia (AML); chronic lymphoid leukemia (CLL); chronic myeloid leukemia (CML); Hodgkin’s lymphoma (HL) and non-Hodgkin’s lymphoma (NHL). Presumptive species identi- fication of fungi was performed using conventional methods like colony characteristics on CHROMagar Candida medium, germ tube production, and assessing the morphology fungi on corn meal agar. Confirmation of presumptive candida isolates was performed using PCR-RFLP. Results: From a total of 50, 14 patients (28%) had positive oral candidiasis. Candida albicans (57.14%) was the most com- mon species followed by Candida glabrata (14.28%), Candida parapsilosis (14.28%), Candida krusei (7.14%) and Candida kefyr (7.14%). Candida albicans had the highest rate of oral infection in ALL (35.71%) and then NHL (28.57%) patients. Conclusion: The results indicate that oral candidiasis is a prevalent fungal infection in the patients with hematologic ma- lignancies with C. albicans being the main etiological agent. However, other species of Candida cause similar infections in these patients.

Identification of Candida spp. isolated from oral mucosa in patients with leukemias and lymphomas in Iran

BACKGROUND AND OBJECTIVES

Oral candidiasis is a serious problem for immunocompromised patients, especially patients with hematological malignancies. After becoming a systemic candidiasis it is difficult to diagnose, control and treat in individuals with hematological malignancies. The aim of this study was to diagnose candidiasis in the oral mucosa of patients with leukemias and lymphomas in a timely manner in order to prevent their progression to systemic candidiasis.

MATERIALS AND METHODS

In this cross sectional study, 50 clinical samples were collected from the mouth of patients with hematological malignancies undergoing chemotherapy from the oncology units of teaching hospitals in Kerman, Iran. Patients were from Kerman, Sistan-Baluchestan and Hormozgan in south-eastern Iran. Sampling was restricted to patients with diagnosed acute lymphoid leukemia (ALL); acute myeloid leukemia (AML); chronic lymphoid leukemia (CLL); chronic myeloid leukemia (CML); Hodgkin's lymphoma (HL) and non-Hodgkin's lymphoma (NHL). Presumptive species identification of fungi was performed using conventional methods like colony characteristics on CHROMagar Candida medium, germ tube production, and assessing the morphology fungi on corn meal agar. Confirmation of presumptive candida isolates was performed using PCR-RFLP.

RESULTS

From a total of 50, 14 patients (28%) had positive oral candidiasis. Candida albicans (57.14%) was the most common species followed by Candida glabrata (14.28%), Candida parapsilosis (14.28%), Candida krusei (7.14%) and Candida kefyr (7.14%). Candida albicans had the highest rate of oral infection in ALL (35.71%) and then NHL (28.57%) patients.

CONCLUSION

The results indicate that oral candidiasis is a prevalent fungal infection in the patients with hematologic malignancies with C. albicans being the main etiological agent. However, other species of Candida cause similar infections in these patients.

Effect of biogenic selenium nanoparticles on ERG11 and CDR1 gene expression in both fluconazole-resistant and -susceptible Candida albicans isolates

Background and Purpose

Candida albicans is the most common Candida species (sp.) isolated from fungal infections. Azole resistance in Candida species has been considerably increased in the last decades. Given the toxicity of the antimicrobial drugs, resistance to antifungal agents, and drug interactions, the identification of new antifungal agents seems essential. In this study, we assessed the antifungal effects of biogenic selenium nanoparticles on C. albicans and determined the expression of ERG11 and CDR1 genes.

Materials and Methods

Selenium nanoparticles were synthesized with Bacillus sp. MSH-1. The ultrastructure of selenium nanoparticles was evaluated with a transmission electron microscope. The antifungal susceptibility test was performed according to the modified Clinical and Laboratory Standards Institute M27-A3 standard protocol. The expression levels of the CDR1 and ERG11 genes were analyzed using the quantitative real-time polymerase chain reaction (PCR) assay.

Results

The azole-resistant C. albicans and wild type C. albicans strains were inhibited by 100 and 70 µg/mL of selenium nanoparticle concentrations, respectively. The expression of CDR1 and ERG11 genes was significantly down-regulated in these selenium nanoparticle concentrations.

Conclusion

As the findings indicated, selenium nanoparticles had an appropriate antifungal activity against fluconazole-resistant and -susceptible C.albicans strains. Accordingly, these nanoparticles reduced the expression of CDR1 and ERG11 genes associated with azole resistance. Further studies are needed to investigate the synergistic effects of selenium nanoparticles using other antifungal drugs.

Mechanisms of resistance to fluconazole in Candida albicans clinical isolates from Iranian HIV-infected patients with oropharyngeal candidiasis

OBJECTIVES

The opportunistic pathogen Candida albicans is the major agent of oropharyngeal candidiasis (OPC) in HIV/AIDS patients. The increased use of fluconazole can lead to the emergence of azole-resistant strains and treatment failures in PLWH (people living with HIV) receiving long-term therapy for OPC. The purpose of this study was to evaluate CDR1, CDR2, MDR1, and ERG11 gene expression in C. albicans clinically isolated from HIV-infected patients in Iran.

PATIENTS AND METHODS

In this study, we evaluated the molecular mechanisms of azole resistance in 20 fluconazole-resistant C. albicans isolates obtained from Iranian HIV-infected patients with oropharyngeal candidiasis by Real-Time polymerase chain reaction.

RESULTS

The overexpression of drug efflux pump CDR1 gene was found to be the major resistance mechanism observed in these isolates. The overexpression of the CDR1 gene correlated strongly with increasing resistance to fluconazole (P<0.05). Additionally, an increased level of mRNA in ERG11 was not observed in any of the tested isolates.

CONCLUSIONS

Our findings suggested that the CDR1 gene expression to fluconazole resistance in C. albicans is greater than other known genes.