A new form of amphotericin B - the complex with copper (II) ions - downregulates sTNFR1 shedding and changes the activity of genes involved in TNF-induced pathways: AmB-Cu2+ downregulates sTNFR1 shedding and changes the activity of genes involved in TNF-induced pathways

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.

Comprehensive molecular and clinical analysis of adalimumab and etanercept therapeutic potential in patients with psoriatic arthritis

Introduction

Adalimumab and etanercept are drugs used in anti-TNF therapy in patients with psoriasis and psoriatic arthritis. Despite the molecular targeting of these drugs, the loss of pharmacological response to treatment is observed in patients. The development of personalized medicine makes it possible to use not only clinical parameters of disease severity, but also molecular marker systems.

Aim

The aim of the study was to evaluate the changes in TNF-α, TNFR1, and TNFR2 expression in relation to parameters of disease severity (PASI, BSA, DAS28) in patients treated with adalimumab and etanercept. We have attempted to determine whether changes in the TNF-α, TNFR1, and TNFR2 expression profile may be a useful molecular marker of the therapeutic potential of anti-TNF drugs.

Material and methods

The study group consisted of 3 patients initially treated with adalimumab, followed by etanercept. The control group included 20 healthy volunteers. The expression profile of TNFR1 and TNFR2 was determined at the mRNA level, while TNF-α expression was evaluated at the transcriptome and proteome levels using the RT-qPCR method (transcriptional activity assay) and MALDI-TOF MS (protein level assessment).

Results

Depending on the drug, different expression profiles of the studied cytokines are observed.

Conclusions

The obtained data indicate that TNF-α, TNFR1, and TNFR2 may be useful markers of the efficacy of anti-TNF therapy, thus complementing clinical parameters.

Amphotericin B-conjugated polypeptide hydrogels as a novel innovative strategy for fungal infections

The present work is focused on the design and development of novel amphotericin B (AmB)-conjugated biocompatible and biodegradable polypeptide hydrogels to improve the antifungal activity. Using three kinds of promoting self-assembly groups (2-naphthalene acetic acid (Nap), naproxen (Npx) and dexamethasone (Dex)) and polypeptide sequence (Phe-Phe-Asp-Lys-Tyr, FFDKY), we successfully synthesized the Nap-FFDK(AmB)Y gels, Npx-FFDK(AmB)Y gels and Dex-FFDK(AmB)Y gels. The AmB-conjugated hydrogelators are highly soluble in different aqueous solutions. The cryo-transmission electron microscopy and scanning electron microscopy micrographs of hydrogels afford nanofibres with a width of 20-50 nm. Powder X-ray diffraction analyses demonstrate that the crystalline structures of the AmB and Dex are changed into amorphous structures after the formation of hydrogels. Circular dichroism spectra of the solution of blank carriers and the corresponding drug deliveries further help elucidate the molecular arrangement in gel phase, indicating the existence of turn features. The in vitro drug releases suggest that the AmB-conjugated hydrogels are suitable as drug-controlled release vehicles for hydrophobic drugs. The antifungal effect of AmB-conjugated hydrogels significantly exhibits the antifungal activity against Candida albicans. The results of the present study indicated that the AmB-conjugated hydrogels are suitable carriers for poorly water soluble drugs and for enhancement of therapeutic efficacy of antifungal drugs.

Impact of Antibiotics on the Proliferation and Differentiation of Human Adipose-Derived Mesenchymal Stem Cells

Adipose tissue is a promising source of mesenchymal stem cells. Their potential to differentiate and regenerate other types of tissues may be affected by several factors. This may be due to in vitro cell-culture conditions, especially the supplementation with antibiotics. The aim of our study was to evaluate the effects of a penicillin-streptomycin mixture (PS), amphotericin B (AmB), a complex of AmB with copper (II) ions (AmB-Cu²⁺) and various combinations of these antibiotics on the proliferation and differentiation of adipose-derived stem cells in vitro. Normal human adipose-derived stem cells (ADSC, Lonza) were routinely maintained in a Dulbecco’s Modified Eagle Medium (DMEM) that was either supplemented with selected antibiotics or without antibiotics. The ADSC that were used for the experiment were at the second passage. The effect of antibiotics on proliferation was analyzed using the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) and sulforhodamine-B (SRB) tests. Differentiation was evaluated based on Alizarin Red staining, Oil Red O staining and determination of the expression of ADSC, osteoblast and adipocyte markers by real-time RT-qPCR. The obtained results indicate that the influence of antibiotics on adipose-derived stem cells depends on the duration of exposure and on the combination of applied compounds. We show that antibiotics alter the proliferation of cells and also promote natural osteogenesis, and adipogenesis, and that this effect is also noticeable in stimulated osteogenesis.

Biofabricated Silver Nanoparticles Synergistically Activate Amphotericin B Against Mature Biofilm Forms of Candida Albicans

Background:

Biofilm formation by Candida albicans is a significant clinical challenge. Fungal biofilms are resistant to most of the currently available antifungal agents. Amphotericin-B (AmB) is an antifungal agent used for the treatment of systematic fungal infections but it is well known for its toxicities and side-effects. Novel approaches are needed to treat these infections that can reduce its toxicities.

Objectives:

Current study aims to evaluate the efficacy of silver nanoparticles (SNPs) alone and in combination with AmB against growth and biofilm formation in C. albicans.

Methods:

Combinations of SNP-AmB were tested against planktonic growth and biofilm formation in vitro. Micro broth dilution method was used to study planktonic growth and biofilm formation. The fractional inhibitory concentration indices (FICI) were calculated by using a checkerboard format. Biofilm formation was analyzed by using XTT-metabolic assay.

Results:

MIC of AmB for developing biofilm was lowered by 16 fold in combination with SNPs. The calculated fractional inhibitory concentration indices were 0.1875 suggesting that this interaction is synergistic. Similarly, the mature biofilms were significantly prevented by SNPs-AmB combination. This interaction was synergistic. Furthermore, interaction between SNPs and AmB against planktonic growth was additive. Hemolytic activity assay was carried out on these drugs and combinations. Drug required for inhibition alone as well as in combination did not exhibit hemolytic activity.

Conclusion:

The combinations with SNPs lead to decreases in the dosage of AmB required for anti-Candida activity. SNPs-AmB combination could be an effective strategy against biofilm formed by C. albicans.

Differential expression of microRNAs and their predicted targets in renal cells exposed to amphotericin B and its complex with copper (II) ions

MicroRNAs (miRNAs) have been reported to regulate essential biological processes, and their expression was shown to be affected by pathological processes and drug-induced toxicity. Amphotericin B (AmB) can cause liver and kidney injury, but a recently developed complex of AmB with copper (II) ions (AmB-Cu²⁺) exhibits a lower toxicity to human renal cells while retaining a high antifungal activity. The aim of our study was to assess AmB-Cu²⁺-induced changes in the miRNA profile of renal cells and examine which biological processes are significantly affected by AmB-Cu²⁺. We also aimed to predict whether differentially expressed miRNAs would influence observed changes in the mRNA profile. miRNA and mRNA profiles in normal human renal proximal tubule epithelial cells (RPTEC) treated with AmB-Cu²⁺ or AmB were appointed with the use of microarray technology. For differentially expressed mRNAs, the PANTHER overrepresentation binomial test was performed. miRNA target interactions (MTIs) were predicted using the miRTar tool. The mRNA profile was much more strongly affected than the miRNA profile, in both AmB-Cu²⁺- and AmB-treated cells. AmB-Cu²⁺ influenced both the miRNA and mRNA profiles much more strongly than AmB. The most affected biological processes were intracellular signal transduction (AmB-Cu²⁺) and signal transduction (AmB). Only a few interactions between differentiating miRNAs and mRNAs were found. Changes in the profiles of genes involved in signal transduction and intracellular signal transduction may not result from interactions with differentially expressed miRNAs. Changes in the miRNA profile suggest the possible influence of tested drugs on the regulation of fibrosis via a miRNA-dependent mechanism.