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Silver Nanoparticles and Ionic Silver Have Opposite Effects on Spontaneous Activity and Pharmacological Responses in Neuronal Networks In Vitro
Citation:
Strickland, J., J. Crooks, D. Hall, K. Dreher, AND Tim Shafer. Silver Nanoparticles and Ionic Silver Have Opposite Effects on Spontaneous Activity and Pharmacological Responses in Neuronal Networks In Vitro. Presented at Society of Toxicology Meeting, Phoenix, AZ, March 23 - 27, 2014.
Impact/Purpose:
Abstract to be presented at the Society of Toxicology Meeting, March 23-27, 2014, Phoenix, AZ
Description:
CONTROL ID: 1850472 CONTACT (NAME ONLY): Timothy Shafer Abstract Details PRESENTATION TYPE: Platform or Poster CURRENT CATEGORY: Nanotoxicology, In Vitro | Neurotoxicity, General | Neurotoxicity, Metals KEYWORDS: Nanoparticle, Neurotoxicity, microelectrode array. DATE/TIME LAST MODIFIED: September 30, 2013, 2:35 PM DATE/TIME SUBMITTED: Abstract TITLE: SILVER NANOPARTICLES AND IONIC SILVER HAVE OPPOSITE EFFECTS ON SPONTANEOUS ACTIVITY AND PHARMACOLOGICAL RESPONSES IN NEURONAL NETWORKS IN VITRO AUTHORS (LAST NAME, FIRST NAME): Strickland, Jenna D.1; Crooks, James2; Hall, Diana2; Dreher, Kevin2; Shafer, Timothy J.2 SPONSOR NAME: None INSTITUTIONS (ALL): 1. NCSU, Raleigh, NC, United States. 2. NHEERL, ORD, U.S. Environmental Protection Agency, Research Triangle Park, NC, United States. ABSTRACT BODY: Silver nanoparticles (Ag NP) are used in a wide range of consumer and medical products because of their antimicrobial properties. In vivo studies have demonstrated that Ag NPs translocate to distal organs, including the brain, following inhalation and ingestion. Thus, it is essential to examine neuronal function as part of assessing potential human health impacts of Ag NPs. The present study examined effects of AgNO3, 3 citrate coated and 3 PVP coated Ag NPs (10, 50, and 75 nm) on network function in primary cultures of cortical neurons using microelectrode array recordings. Non-cytotoxic concentrations of Ag NPs and AgNO3 (0.078-0.63 and 0.08-1.7 μg/ml, respectively) were determined after a 48 hr exposure using Cell Titer Blue and Neutral Red assays. Between days 12-19 in vitro, baseline activity (1 hr) was recorded prior to exposure to Ag NPs. Changes in number of total spikes (TS) and number of active electrodes (AE), relative to controls, were assessed 1, 24 and 48 hr after exposure to FBS pre-coated Ag NP suspensions or AgNO3. After 48 hr, the response to a challenge with the GABAA antagonist, bicuculline (BIC; 25 µM), was assessed. Citrate coated 10 nm Ag NP caused statistically significant concentration-related increases in AEs at 24 hr. After BIC treatment, PVP coated 75 nm Ag NP caused statistically significant increases in AE (0.6 μg/ml) and TS (0.3 μg/ml). AgNO3 had opposite effects on TS and AEs, causing statistically significant decreases in AEs (0.9 and 1.7 μg/ml), negative concentration-related trends in AEs at 24 and 48 hr, and a significant concentration-related decrease in TS following BIC challenge. These results indicate that Ag NP size and coating affect their ability to disrupt either spontaneous or GABAA receptor mediated neuronal activity in vitro. In addition, the direction of the effect on neuronal activity for Ag NP was opposite that of AgNO3, indicating ionic silver does not mediate these effects. (This abstract does not reflect USEPA Policy.)