Coadministration of Liposomal Amphotericin B and Contrast Medium Does Not Increase Risk of Kidney Injury

Conjugates of amphotericin B to resolve challenges associated with its delivery

INTRODUCTION

Amphotericin B (AmB), a promising antifungal and antileishmanial drug, acts on the membrane of microorganisms. The clinical use of AmB is limited due to issues associated with its delivery including poor solubility and bioavailability, instability in acidic media, poor intestinal permeability, dose and aggregation state dependent toxicity, parenteral administration, and requirement of cold chain for transport and storage, etc.

AREAS COVERED

Scientists have formulated and explored various covalent conjugates of AmB to reduce its toxicity with increase in solubility, oral bioavailability, and payload or loading of AmB by using various polymers, lipids, carbon-based nanocarriers, metallic nanoparticles, and vesicular carriers, etc. In this article, we have reviewed various conjugates of AmB with polymers and nanomaterials explored for its delivery to give a deep insight regarding further exploration in future.

EXPERT OPINION

Covalent conjugates of AmB have been investigated by scientists, and preliminary in vitro and animal investigations have given successful results, which are required to be validated further with systematic investigation on safety and therapeutic efficacy in animals followed by clinical trials.

Self-Assembling Myristoylated Human α-Defensin 5 as a Next-Generation Nanobiotics Potentiates Therapeutic Efficacy in Bacterial Infection

The increasing prevalence of antibacterial resistance globally underscores the urgent need to the update of antibiotics. Here, we describe a strategy for inducing the self-assembly of a host-defense antimicrobial peptide (AMP) into nanoparticle antibiotics (termed nanobiotics) with significantly improved pharmacological properties. Our strategy involves the myristoylation of human α-defensin 5 (HD5) as a therapeutic target and subsequent self-assembly in aqueous media in the absence of exogenous excipients. Compared with its parent HD5, the C-terminally myristoylated HD5 (HD5-myr)-assembled nanobiotic exhibited significantly enhanced broad-spectrum bactericidal activity in vitro. Mechanistically, it selectively killed Escherichia coli ( E. coli) and methicillin-resistant Staphylococcus aureus (MRSA) through disruption of the cell wall and/or membrane structure. The in vivo results further demonstrated that the HD5-myr nanobiotic protected against skin infection by MRSA and rescued mice from E. coli-induced sepsis by lowering the systemic bacterial burden and alleviating organ damage. The self-assembled HD5-myr nanobiotic also showed negligible hemolytic activity and substantially low toxicity in animals. Our findings validate this design rationale as a simple yet versatile strategy for generating AMP-derived nanobiotics with excellent in vivo tolerability. This advancement will likely have a broad impact on antibiotic discovery and development efforts aimed at combating antibacterial resistance.

Retrospective Cohort Analysis of Liposomal Amphotericin B Nephrotoxicity in Patients with Hematological Malignancies

We retrospectively examined the incidence, onset, risk factors, and outcomes of renal injury during 103 treatment courses of liposomal amphotericin B (L-AMB) in 97 adult patients with hematological malignancies. All the patients were analyzed before, during, and after the administration of L-AMB, and renal injury was graded according to the RIFLE criteria (risk, injury, failure, loss of function, end-stage renal disease). Most patients (87.3%) received L-AMB at 3 mg/kg of body weight/day. Nearly two-thirds (61.7%) of the treatment courses did not meet any RIFLE category for renal injury, while 19.4% of patients were classified at risk, 13.6% met an injury classification, and 5.8% were categorized as developing renal failure. However, 15% of the patients developed renal injury within 48 h of the onset of multiorgan failure associated with sepsis, bleeding, or progressing malignancy. When these patients were analyzed as a competing risk for L-AMB-associated renal injury (RIFLE category I or above) in a multivariate Cox regression model, receipt of cyclosporine (subhazard ratio [SHR], 2.62; 95% confidence interval [CI], 1.10 to 6.27; P = 0.03), cyclosporine plus furosemide at ≥40 mg/day (SHR, 5.46; 95% CI, 1.89 to 15.74; P = 0.002), or cyclosporine plus foscarnet (SHR, 9.03; 95% CI, 3.68 to 22.14; P < 0.0001) were the only comedications significantly associated with increased rates of renal injury. The cumulative incidence of L-AMB renal injury during the first 10 days of therapy was 7% overall but only 3% in patients who were not receiving cyclosporine. Hence, the renal risk of L-AMB therapy may be lessened if patients are switched to alternative agents after 7 to 10 days or if aggressive diuresis and/or foscarnet is avoided, especially among patients receiving calcineurin inhibitors.