Evaluating Nanoparticle Interactions with SkinEPA Grant Number: R831715
Title: Evaluating Nanoparticle Interactions with Skin
Investigators: Monteiro-Riviere, Nancy A. , Riviere, Jim E.
Institution: North Carolina State University
EPA Project Officer: Hahn, Intaek
Project Period: September 18, 2004 through September 30, 2007
Project Amount: $328,972
RFA: Exploratory Research to Anticipate Future Environmental Issues: Impacts of Manufactured Nanomaterials on Human Health and the Environment (2003) RFA Text | Recipients Lists
Research Category: Health , Safer Chemicals , Nanotechnology , Health Effects
The focus of this research is to assess the nature of interaction between manufactured nanoparticles and the skin, including dermal absorption, cutaneous toxicity as well as the ability to distribute to the skin after systemic exposure. These studies will utilize iron oxide nanocrystals, cadmium selenide nanocrystals and carbon fullerene nanoparticles which are representative of the broad spectrum of nanoparticles presently being used by industry. Eight particle types selected from these commercially relevant manufactured nanoparticles will be studied to allow assessment of size, shape and composition on absorption, distribution or toxicity to the skin.
All studies will be conducted in three well-characterized in vitro skin models: human skin keratinocyte cell cultures, porcine skin flow-through diffusion cells, and the isolated perfused porcine skin flap (IPPSF). Nanoparticles will be applied topically in three exposure scenarios (neat, water, mineral oil) at two doses to assess potential dermal absorption in the diffusion cell studies and to assess cellular toxicity (light and electron microscopy, viability) and irritation (IL-8 release) in cell culture. Those particles which penetrate skin or cause direct irritation will then be completely characterized in IPPSF studies which have previously been shown to be predictive of in vivo absorption in humans. Similarly, to model nanoparticle uptake into skin after systemic exposure, nanoparticles will be infused into the arterial blood supply of the IPPSF to assess ability to distribute out of the vasculature into the skin. Deposition of particles in epidermal tissue after both infusion and topical exposure will be evaluated using high-resolution electron microscopy.
Presently, there are minimal data available on the interaction between manufactured nanoparticles and biological tissues. The basic requirement for any risk assessment includes information on hazard (e.g. toxicity) and exposure (e.g. absorption). This proposal focuses on the health effects of nanoparticle interactions with the skin. This integrated research program will generate data on the ability of nanoparticles to be toxic to keratinocytes as well as assess the ability of nanoparticles to either be absorbed into skin after topical exposure, or distribute into skin as would occur after systemic exposure by an alternate route of administration. At the conclusion of the research, the boundaries of a dermal risk assessment for manufactured nanoparticle exposure will be available.