ABSTRACT
Amphotericin B (AmB) is one of the most used drugs for the treatment of systemic fungal infections; however, the treatment causes several toxic manifestations, including nephrotoxicity and hemolytic anemia. Chitosan-coated poly(lactide-co-glycolide) (PLGA) nanoparticles containing AmB were developed with the aim to decrease AmB toxicity and propose the oral route for AmB delivery. In this work, the antifungal efficacy of chitosan-coated PLGA nanoparticles containing AmB was evaluated in 20 strains of fungus isolates from patients with vulvovaginal candidiasis (01 Candida glabrata and 03 Candida albicans), bloodstream infections (04 C. albicans and 01 C. tropicalis) and patients with urinary tract infection (04 Candida albicans, 02 Trichosporon asahii, 01 C. guilhermondii, 03 C. glabrata) and 01 Candida albicans ATCC 90028. Moreover, the cytotoxicity over erythrocytes was evaluated. The single-emulsion solvent evaporation method was suitable for obtaining chitosan-coated PGLA nanoparticles containing AmB. Nanoparticles were spherical in shape, presented mean particle size about 460 nm, positive zeta potential and encapsulation efficiency of 42%. Moreover, nanoparticles prolonged the AmB release. All the strains were susceptible to plain AmB and nanostructured AmB, according to EUCAST breakpoint version 8.1 (resistant > 1 µg/mL), using broth microdilution method. In C. albicans (urine, blood, and vulvovaginal secretion isolates, and 1 ATCC), the MIC value of AmB-loaded nanoparticles varied from 0.25 to 0.5 µg/mL and EUCAST varied from 0.03 to 0.5 µg/mL. In urine and vulvovaginal secretion isolates of C. glabrata, the MIC value of AmB-loaded nanoparticles varied from 0.25 to 0.5 µg/mL and EUCAST varied from 0.03 to 0.015 µg/mL. In urine isolates of C. guilhermondii, the MIC value of AmB-loaded nanoparticles was 0.12 µg/mL and EUCAST was 0.06 µg/mL. In blood isolates of C. tropicalis, the MIC value of AmB-loaded nanoparticles was 0.5 µg/mL and EUCAST was 0.25 µg/mL. Finally, in urine isolates of T asahii, the MIC value of AmB-loaded nanoparticles was 1 µg/mL and EUCAST varied from 0.5 to 1 µg/mL. In the cytotoxicity assay, plain AmB was highly hemolytic (100% in 24 h) while AmB-loaded chitosan/PLGA nanoparticles presented negligible hemolysis.
Subject(s)
Amphotericin B/pharmacology , Antifungal Agents/pharmacology , Candida/drug effects , Chitosan/metabolism , Drug Carriers/metabolism , Lactic Acid/metabolism , Polyglycolic Acid/metabolism , Trichosporon/drug effects , Animals , Candida/isolation & purification , Candidemia/microbiology , Candidiasis, Vulvovaginal/microbiology , Female , Humans , Microbial Sensitivity Tests , Nanoparticles/metabolism , Polylactic Acid-Polyglycolic Acid Copolymer , Trichosporon/isolation & purification , Urinary Tract Infections/microbiologyABSTRACT
In this study, poly(L-lactide) (PLA) nanoparticles containing amphotericin B (AmB) were developed, and the in vitro cytotoxicity to human erythrocytes and efficacy on strains of Candida spp. were evaluated. The nanoparticles were prepared using an emulsion/solvent evaporation method and were characterized with respect to size, size distribution, AmB encapsulation efficiency, AmB state of aggregation, and AmB in vitro release profile. The mean particle size was 225 nm, and the AmB encapsulation efficiency was over 69%. The AmB in vitro release profile revealed a burst effect within the first 24 h, which released approximately 10% of AmB, followed by a sustained release of approximately 30% of AmB over 30 days. The AmB nanoparticles presented a very low index of hemolysis compared to free AmB, which lysed more than 80% of erythrocytes in the first 2 h of incubation. The AmB-loaded PLA nanoparticles were as effective as free AmB against strains of Candida spp., considering their sustained release profile. Thus, PLA nanoparticles can deliver AmB with reduced toxicity while maintaining its antifungal activity.
Subject(s)
Amphotericin B/pharmacology , Amphotericin B/toxicity , Antifungal Agents/pharmacology , Antifungal Agents/toxicity , Nanoparticles/chemistry , Polyesters/chemistry , Amphotericin B/chemistry , Amphotericin B/pharmacokinetics , Antifungal Agents/chemistry , Antifungal Agents/pharmacokinetics , Candida/drug effects , Erythrocytes , Hemolysis/drug effects , Humans , Microbial Viability/drug effects , Nanoparticles/toxicity , Particle Size , Polyesters/toxicityABSTRACT
Apocynin (APO), curcumin (CUR) and vanillin (VAN) are o-methyl catechols widely studied due their antioxidant and antitumour properties. The effect of treatment with these o-methyl catechols on tamoxifen (TAM)-induced cytotoxicity in normal and tumour cells was studied. The cytotoxicity of TAM on red blood cells (RBC) was performed by haemoglobin or K(+)release and on polymorphonuclear leukocytes (PMNs) by trypan blue dye exclusion method. Cytotoxic activity was assessed in human chronic myeloid leukemia (K562) cell line by (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide). According the release of haemoglobin and K(+), the CUR showed a decrease in TAM cytotoxicity on RBC; however, in PMN, APO, CUR and VAN showed increased of these cells viability. VAN presented the highest cytotoxicity on K562 cells, followed by APO and CUR. These results point the potential therapeutic value of these o-methyl catechols with TAM, particularly of CUR, which potentiates the cytotoxic effects of TAM on K562 cells and also decreases TAM-associated cytotoxicity on RBC and PMN.
