Potential lipid-based strategies of amphotericin B designed for oral administration in clinical application

Antifungal Plant Defensins as an Alternative Tool to Combat Candidiasis

Currently, the spread of fungal infections is becoming an urgent problem. Fungi of the Candida genus are opportunistic microorganisms that cause superficial and life-threatening systemic candidiasis in immunocompromised patients. The list of antifungal drugs for the treatment of candidiasis is very limited, while the prevalence of resistant strains is growing rapidly. Therefore, the search for new antimycotics, including those exhibiting immunomodulatory properties, is of great importance. Plenty of natural compounds with antifungal activities may be extremely useful in solving this problem. This review evaluates the features of natural antimicrobial peptides, namely plant defensins as possible prototypes of new anticandidal agents. Plant defensins are important components of the innate immune system, which provides the first line of defense against pathogens. The introduction presents a brief summary regarding pathogenic Candida species, the pathogenesis of candidiasis, and the mechanisms of antimycotic resistance. Then, the structural features of plant defensins, their anticandidal activities, their mechanisms of action on yeast-like fungi, their ability to prevent adhesion and biofilm formation, and their combined action with conventional antimycotics are described. The possible mechanisms of fungal resistance to plant defensins, their cytotoxic activity, and their effectiveness in in vivo experiments are also discussed. In addition, for the first time for plant defensins, knowledge about their immunomodulatory effects is also presented.

Advances in nanotechnology for improving the targeted delivery and activity of amphotericin B (2011-2023): a systematic review

Amphotericin B (AmB) is a broad-spectrum therapeutic and effective drug, but it has serious side effects of toxicity and solubility. Therefore, reducing its toxicity should be considered in therapeutic applications. Nanotechnology has paved the way to improve drug delivery systems and reduce toxicity. The present study, for the first time, comprehensively reviews the studies from 2011 to 2023 on reducing the in vitro toxicity of AmB. The findings showed that loading AmB with micellar structures, nanostructured lipid carriers, liposomes, emulsions, poly lactide-co-glycolide acid, chitosan, dendrimers, and other polymeric nanoparticles increases the biocompatibility and efficacy of the drug and significantly reduces toxicity. In addition, modified carbon nanoparticles (including graphene, carbon nanotubes, and carbon dots) with positively charged amine groups, PEI, and other components showed favorable drug delivery properties. Uncoated and coated magnetic nanoparticles and silver NPs-AmB composites had less cytotoxicity and more antifungal activity than free AmB. Citrate-reduced GNPs and lipoic acid-functionalized GNPs were also effective nanocarriers to reduce AmB cytotoxicity and improve anti-leishmania efficacy. In addition, zinc oxide-NPs and PEGylated zinc oxide-NPs showed favorable antifungal activity and negligible toxicity. According to a review study, carbon-based nanoparticles, metal nanoparticles, and especially polymer nanoparticles caused some reduction in the toxicity and improved solubility of AmB in water. Overall, considering the discussed nanocarriers, further research on the application of nanotechnology as a cost-effective candidate to improve the efficiency and reduce the cytotoxicity of AmB is recommended.

Multi-functional Chitosan Polymeric Micelles for improving the oral bioavailability of Paclitaxel based on synergistic effect

A novel multi-functional micelle delivery system was developed for enhancing the oral absorption of paclitaxel (PTX). The delivery carriers were constructed by modifying chitosan-stearic acid (CS-SA) micelles with L-carnitine (LC) and co-encapsulating quercetin (Que), and the PTX-loaded micelles were prepared by film-sonication dispersing technique. The as-prepared micelles showed homogeneous spherical shapes with a small particle size of 148.3 ± 1.7 nm, high drug loading of 7.05% and low critical micelle concentration (CMC) of 16.89 µg/ml. Compared to the in-house PTX formulation similar to the commercial injection Taxol™, the target PTX-loaded micelles had obvious sustained-release effects and exhibited an oral relative bioavailability of 168.08%. The cellular uptake studies of Caco-2 cells confirmed the micellar modification of LC and the co-loading of Que played important roles in promoting the absorption of drug loaded in micelles. The CYP3A4 enzyme test demonstrated the micelles had an inhibitory effect on the metabolic enzyme due to the presence of Que. These findings confirmed the potential of the multi-functional chitosan polymeric micelles based on synergistic effect as an effective oral delivery system.

Advancements and challenges in antifungal therapeutic development

Over recent decades, the global burden of fungal disease has expanded dramatically. It is estimated that fungal disease kills approximately 1.5 million individuals annually; however, the true worldwide burden of fungal infection is thought to be higher due to existing gaps in diagnostics and clinical understanding of mycotic disease. The development of resistance to antifungals across diverse pathogenic fungal genera is an increasingly common and devastating phenomenon due to the dearth of available antifungal classes. These factors necessitate a coordinated response by researchers, clinicians, public health agencies, and the pharmaceutical industry to develop new antifungal strategies, as the burden of fungal disease continues to grow. This review provides a comprehensive overview of the new antifungal therapeutics currently in clinical trials, highlighting their spectra of activity and progress toward clinical implementation. We also profile up-and-coming intracellular proteins and pathways primed for the development of novel antifungals targeting their activity. Ultimately, we aim to emphasize the importance of increased investment into antifungal therapeutics in the current continually evolving landscape of infectious disease.

Carrier-Tumor Cell Membrane Interactions for Optimized Delivery of a Promising Drug, 4(RS)-4-F4t-Neuroprostane

Nanomedicines engineered to deliver molecules with therapeutic potentials, overcoming drawbacks such as poor solubility, toxicity or a short half-life, are targeted towards their cellular destination either passively or through various elements of cell membranes. The differences in the physicochemical properties of the cell membrane between tumor and nontumor cells have been reported, but they are not systematically used for drug delivery purposes. Thus, in this study, a new approach based on a match between the liposome compositions, i.e., membrane fluidity, to selectively interact with the targeted cell membrane was used. Lipid-based carriers of two different fluidities were designed and used to deliver 4(RS)-4-F4t-Neuroprostane (F4t-NeuroP), a potential antitumor molecule derived from docosahexaenoic acid (DHA). Based on its hydrophobic character, F4t-NeuroP was added to the lipid mixture prior to liposome formation, a protocol that yielded over 80% encapsulation efficiency in both rigid and fluid liposomes. The presence of the active molecule did not modify the liposome size but increased the liposome negative charge and the liposome membrane fluidity, which suggested that the active molecule was accommodated in the lipid membrane. F4t-NeuroP integration in liposomes with a fluid character allowed for the selective targeting of the metastatic prostate cell line PC-3 vs. fibroblast controls. A significant decrease in viability (40%) was observed for the PC-3 cancer line in the presence of F4t-NeuroP fluid liposomes, whereas rigid F4t-NeuroP liposomes did not alter the PC-3 cell viability. These findings demonstrate that liposomes encapsulating F4t-NeuroP or other related molecules may be an interesting model of drug carriers based on membrane fluidity.

Prevention and management of antibiotic associated acute kidney injury in critically ill patients: new insights

PURPOSE OF REVIEW

Drug associated kidney injury (D-AKI) occurs in 19-26% of hospitalized patients and ranks as the third to fifth leading cause of acute kidney injury (AKI) in the intensive care unit (ICU). Given the high use of antimicrobials in the ICU and the emergence of new resistant organisms, the implementation of preventive measures to reduce the incidence of D-AKI has become increasingly important.

RECENT FINDINGS

Artificial intelligence is showcasing its capabilities in early recognition of at-risk patients for acquiring AKI. Furthermore, novel synthetic medications and formulations have demonstrated reduced nephrotoxicity compared to their traditional counterparts in animal models and/or limited clinical evaluations, offering promise in the prevention of D-AKI. Nephroprotective antioxidant agents have had limited translation from animal studies to clinical practice. The control of modifiable risk factors remains pivotal in avoiding D-AKI.

SUMMARY

The use of both old and new antimicrobials is increasingly important in combating the rise of resistant organisms. Advances in technology, such as artificial intelligence, and alternative formulations of traditional antimicrobials offer promise in reducing the incidence of D-AKI, while antioxidant medications may aid in minimizing nephrotoxicity. However, maintaining haemodynamic stability using isotonic fluids, drug monitoring, and reducing nephrotoxic burden combined with vigilant antimicrobial stewardship remain the core preventive measures for mitigating D-AKI while optimizing effective antimicrobial therapy.

Antifungals: From Pharmacokinetics to Clinical Practice

The use of antifungal drugs started in the 1950s with polyenes nystatin, natamycin and amphotericin B-deoxycholate (AmB). Until the present day, AmB has been considered to be a hallmark in the treatment of invasive systemic fungal infections. Nevertheless, the success and the use of AmB were associated with severe adverse effects which stimulated the development of new antifungal drugs such as azoles, pyrimidine antimetabolite, mitotic inhibitors, allylamines and echinochandins. However, all of these drugs presented one or more limitations associated with adverse reactions, administration route and more recently the development of resistance. To worsen this scenario, there has been an increase in fungal infections, especially in invasive systemic fungal infections that are particularly difficult to diagnose and treat. In 2022, the World Health Organization (WHO) published the first fungal priority pathogens list, alerting people to the increased incidence of invasive systemic fungal infections and to the associated risk of mortality/morbidity. The report also emphasized the need to rationally use existing drugs and develop new drugs. In this review, we performed an overview of the history of antifungals and their classification, mechanism of action, pharmacokinetic/pharmacodynamic (PK/PD) characteristics and clinical applications. In parallel, we also addressed the contribution of fungi biology and genetics to the development of resistance to antifungal drugs. Considering that drug effectiveness also depends on the mammalian host, we provide an overview on the roles of therapeutic drug monitoring and pharmacogenomics as means to improve the outcome, prevent/reduce antifungal toxicity and prevent the emergence of antifungal resistance. Finally, we present the new antifungals and their main characteristics.