An Evaluation of Acute Toxicity of Colloidal Silver Nanoparticles

Abstract

ABSTRACT. Tests for acute oral toxicity, eye irritation, corrosion and dermal toxicity of colloidal silver nanoparticles (AgNPs) were conducted in laboratory animals following OECD guidelines. Oral administration of AgNPs at a limited dose of 5,000 mg/kg produced neither mortality nor acute toxic signs throughout the observation period. Percentage of body weight gain of the mice showed no significant difference between control and treatment groups. In the hematological analysis, there was no significant difference between mice treated with AgNPs and controls. Blood chemistry analysis also showed no differences in any of the parameter examined. There was neither any gross lesion nor histopathological change observed in various organs. The results indicated that the LD 50 of colloidal AgNPs is greater than 5,000 mg/kg body weight. In acute eye irritation and corrosion study, no mortality and toxic signs were observed when various doses of colloidal AgNPs were instilled in guinea pig eyes during 72 hr observation period. However, the instillation of AgNPs at 5,000 ppm produced transient eye irritation during early 24 hr observation time. No any gross abnormality was noted in the skins of the guinea pigs exposed to various doses of colloidal AgNPs. In addition, no significant AgNPs exposure relating to dermal tissue changes was observed microscopically. In summary, these findings of all toxicity tests in this study suggest that colloidal AgNPs could be relatively safe when administered to oral, eye and skin of the animal models for short periods of time.KEY WORDS: acute toxicity, colloidal silver nanoparticles, dermal, eye, oral.J. Vet. Med. Sci. 73(11): 1417-1423, 2011 Engineered nanoparticles (NP) are defined as materials produced within the nanoscale range of 1-100 nm in length or diameter that exhibit unique novel properties of the structural integrity as well as physical and chemical properties [26]. Over the past few decades, nanomaterials have had a great impact and gained enormous attention in science, technology and business because of their potential for achieving specific processes and selectivity. Although the applications and benefits of these engineered nanomaterials are extensively and currently being widely used in modern technology and many commercial and medical sectors, there is still limited information concerning human health and environmental impacts. Several studies expected that nanoparticles could lead to unexpected health or environmental hazards because of their unique properties such as extremely high surface area and increased reactivity [7].Silver nanoparticles (AgNPs), one of the most commonly used metal-nanoparticles, have been known to have a wide range of applications including solar energy absorption coatings, chemical catalysts and especially antimicrobial agents. AgNPs have potentials for inhibitory and bactericidal effects as well as retarding the growth of mold, harmful spores and germs [5]. Compared to bulk silver metal, AgNPs are expected to have higher antimicrobial activity...

Immunomodulatory properties of silver nanoparticles contribute to anticancer strategy for murine fibrosarcoma

“…In the case of MSA binding to AgNPs, negligible variations were observed in the characteristic peak of the amide I bands, but the characteristic peak of the amide II band shifted to a 40 cm 21 higher wavenumber, suggesting that there is a coordination interaction between the silver ions and MSA. Most notably, the characteristic peak of the amide A band shifts to the higher wavenumber of 3445 cm 21 . Such a large variation further suggests that coordination has formed between AgNPs and the amine groups of MSA, which plays an important role in the formation of MSA-stabilized AgNPs.…”

“…Thus, recent findings suggest that there is a relationship between AgNPs and the immune system, however, there are almost no reports on the AgNP immunomodulation of tumor-bearing mice. Although there are several reports on the toxicity of AgNPs, [21][22][23][24][25] there is a paucity of toxicity studies on the AgNP dose-response in mice. Hence, the present investigation was designed to determine the effects of AgNPs at different doses in mice and to study their effects on murine fibrosarcoma.…”

Nanosilver – Harmful effects of biological activity

“…W badaniach przeprowadzonych zgodnie z wytycznymi TG 404 i 405 (Test Guideline -TG) Organizacji Współpracy Gospodarczej i Rozwoju (Organization Economic Cooperation and Development -OECD) nanocząstki srebra nie działały drażniąco na skórę świnek morskich (18), jednak w przypadku królików wyniki nie były jednoznaczne. U królików, którym nakładano nanocząstki wielkości 10-20 nm, wystąpi-ły objawy podrażnienia skóry (rumień i obrzęk) (19).…”

“…U świnek morskich zaobserwowano natomiast przekrwienie spojówek, które ustę-powało po 72 godz. od podania srebra koloidalnego (10-20 nm) do worka spojówkowego, co mogło wskazywać na przejściowe działanie drażniące (18).…”

“…Po 4-godzinnym inhalacyjnym narażeniu na nanocząstki srebra (18)(19)(20) Po narażeniu szczurów na nanocząstki srebra (15 nm) drogą inhalacyjną przez 4 tygodnie nie stwierdzono zmian w przyroście masy ciała, parametrach hematologicznych ani biochemicznych (5). W badaniu histopatologicznym zaobserwowano natomiast nieistotne statystycznie zmiany w wątrobie (wakuolizacja cytoplazmatyczna i martwica hepatocytów).…”