In vitro and in vivo evaluation of biologically synthesized silver nanoparticles for topical applications: effect of surface coating and loading into hydrogels.
In the present study, silver nanoparticles (AgNPs) were synthesized via biological reduction of silver nitrate using extract of the fungusFusarium verticillioides(green chemistry principle). The synthesized nanoparticles were spherical and homogenous in size. AgNPs were coated with polyethylene glycol (PEG) 6000, sodium dodecyl sulfate (SDS), and β-cyclodextrin (β-CD). The averaged diameters of AgNPs were 19.2±3.6, 13±4, 14±4.4, and 15.7±4.8 nm, for PEG-, SDS-, and β-CD-coated and uncoated AgNPs, respectively. PEG-coated AgNPs showed greater stability as indicated by a decreased sedimentation rate of particles in their water dispersions. The antibacterial activities of different AgNPs dispersions were investigated against Gram-positive bacteria (methicillin-sensitive and methicillin-resistantStaphylococcus aureus) and Gram-negative bacteria (Escherichia coli) by determination of the minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs). MIC and MBC values were in the range of 0.93-7.5 and 3.75-15 µg/mL, respectively, which were superior to the reported values in literature. AgNPs-loaded hydrogels were prepared from the coated-AgNPs dispersions using several gelling agents (sodium carboxymethyl cellulose [Na CMC], sodium alginate, hydroxypropylmethyl cellulose, Pluronic F-127, and chitosan). The prepared formulations were evaluated for their viscosity, spreadability, in vitro drug release, and antibacterial activity, and the combined effect of the type of surface coating and the polymers utilized to form the gel was studied. The in vivo wound-healing activity and antibacterial efficacy of Na CMC hydrogel loaded with PEG-coated AgNPs in comparison to the commercially available silver sulfadiazine cream (Dermazin®) were evaluated. Superior antibacterial activity and wound-healing capability, with normal skin appearance and hair growth, were demonstrated for the hydrogel formulations, as compared to the silver sulfadiazine cream. Histological examination of the treated skin was performed using light microscopy, whereas the location of AgNPs in the skin epidermal layers was visualized using transmission electron microscopy.
Department of Pharmaceutics and Clinical Pharmacy, Faculty of Pharmacy, Sohag University, Sohag.
Aml I
AI
Mekkawy
Department of Microbiology and Immunology, Faculty of Medicine.
Mohamed A
MA
El-Mokhtar
Department of Botany and Microbiology, Faculty of Science.
Nivien A
NA
Nafady
Department of Botany and Microbiology, Faculty of Science.
Naeima
N
Yousef
Department of Surgery, Faculty of Medicine.
Mostafa A
MA
Hamad
Department of Pharmaceutics, Faculty of Pharmacy.
Sohair M
SM
El-Shanawany
Department of Pharmaceutics, Faculty of Pharmacy.
Ehsan H
EH
Ibrahim
Department of Pharmaceutics, Faculty of Pharmacy; Assiut International Center of Nanomedicine, Al-Rajhi Liver Hospital, Assiut University, Assiut, Egypt; Laboratory for Synthetic-Biologic Interactions, Department of Chemistry, Texas A&M University, College Station, TX, USA; Misr University for Science and Technology, 6th of October, Egypt.
Mahmoud
M
Elsabahy
D000287:Administration, Topical; D000818:Animals; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000494:pharmacology; D020099:Coated Materials, Biocompatible / Q000494:pharmacology*; D004926:Escherichia coli / Q000187:drug effects; D005260:Female; D005670:Fusarium / Q000737:chemistry*; D020100:Hydrogels / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects; D051379:Mice; D008826:Microbial Sensitivity Tests; D010316:Particle Size; D012834:Silver / Q000008:administration & dosage* / Q000494:pharmacology*; D012867:Skin / Q000187:drug effects / Q000382:microbiology / Q000473:pathology / Q000648:ultrastructure; D013056:Spectrophotometry, Ultraviolet; D055672:Static Electricity; D014945:Wound Healing / Q000187:drug effects
D000900:Anti-Bacterial Agents; D020099:Coated Materials, Biocompatible; D020100:Hydrogels; D012834:Silver
antibacterial activity; coating agents; green synthesis; hydrogel; silver nanoparticles; wound healing