Silica–gentamicin nanohybrids: combating antibiotic resistance, bacterial biofilms, and in vivo toxicity

Abstract

IntroductionAntibiotic resistance is a growing concern in health care. Methicillin-resistant Staphylococcus aureus (MRSA), forming biofilms, is a common cause of resistant orthopedic implant infections. Gentamicin is a crucial antibiotic preventing orthopedic infections. Silica–gentamicin (SiO2-G) delivery systems have attracted significant interest in preventing the formation of biofilms. However, compelling scientific evidence addressing their efficacy against planktonic MRSA and MRSA biofilms is still lacking, and their safety has not extensively been studied.Materials and methodsIn this work, we have investigated the effects of SiO2-G nanohybrids against planktonic MRSA as well as MRSA and Escherichia coli biofilms and then evaluated their toxicity in zebrafish embryos, which are an excellent model for assessing the toxicity of nanotherapeutics.ResultsSiO2-G nanohybrids inhibited the growth and killed planktonic MRSA at a minimum concentration of 500 µg/mL. SiO2-G nanohybrids entirely eradicated E. coli cells in biofilms at a minimum concentration of 250 µg/mL and utterly deformed their ultrastructure through the deterioration of bacterial shapes and wrinkling of their cell walls. Zebrafish embryos exposed to SiO2-G nanohybrids (500 and 1,000 µg/mL) showed a nonsignificant increase in mortality rates, 13.4±9.4 and 15%±7.1%, respectively, mainly detected 24 hours post fertilization (hpf). Frequencies of malformations were significantly different from the control group only 24 hpf at the higher exposure concentration.ConclusionCollectively, this work provides the first comprehensive in vivo assessment of SiO2-G nanohybrids as a biocompatible drug delivery system and describes the efficacy of SiO2-G nanohybrids in combating planktonic MRSA cells and eradicating E. coli biofilms.

Antimicrobial and antihemolytic properties of a CNF/AgNP-chitosan film: A potential wound dressing material

“…All samples were then incubated at 36–37 °C for 24 h. The resulting inhibition zone was measured using a caliper [ 28 ]. Gentamicin 0.1% was used as a positive control [ 29 ], and CNF/AgNP-chitosan (100:0) was used as a negative control.…”

Advances in Nanostructures for Antimicrobial Therapy

“…SiO 2 -gentamicin nanohybrids exhibited antibacterial activity against MRSA (MIC: 500 μg/mL) and completely eradicated E. coli cells in biofilms at 250 μg/mL, causing wrinkling of bacterial cell walls and deterioration of the shapes [ 353 ]. Nanostructured Ag@SiO 2 –penicillin NPs containing 33.2 wt% of triangular Ag nanoplates and ca 2.8 wt% of grafted antibiotics showed a strong bactericidal effect against MSSA and MRSA bacteria and showed no cytotoxicity against A431 cell line [ 354 ].…”

Using essential oils to overcome bacterial biofilm formation and their antimicrobial resistance

“…Antibody-based drugs, or prebiotics and probiotics which target bacterial community communication are potential alternatives ( Harbarth et al, 2015 ). Recent novel approaches have included sequencing prokaryote genomes ( Tracanna et al, 2017 ), the use of metal, polymeric, and lipid-based nanoparticles ( Lakshminarayanan et al, 2018 ) and peptide-based antibiotics ( Roshan et al, 2018 ), nanohybrids of silica and antibiotic combination ( Mosselhy et al, 2018 ), and revitalized phage-therapy based techniques ( Kortright et al, 2019 ).…”