The Safety and Immunostimulatory Properties of Amorphous Silica Nanoparticles <10 nm in Diameter
type: CreativeWork
description: Humans are exposed to high levels of amorphous silica on a daily basis, via the diet and the use of cosmetic and pharmaceutical products. Amorphous silica particles (10-200 nm) have also been developed for use in biomedical applications, including as binding agents in tissue repair, drug and gene therapy delivery agents, coatings for medical contrast agents and as vaccine adjuvants. Numerous studies have already been conducted to evaluate the cellular toxicity of these silica particles but still little is known about their effects both in vitro and in vivo, especially of nanosilica particles under 10 nm in diameter. The aim of this thesis was to investigate the cellular and in vivo activity of < 10 nm diameter nanosilica particles with different properties (e.g., size and dissolution rate in dilute conditions) as it may infer upon safety after exposure via the diet and intravenous administration (biomedical applications). First, the cytotoxicity of sub-10 nm nanosilica particles, fully characterized by size, dissolution rate, zeta-potential and by NMR spectroscopy, on immune cell function was assessed using transformed and cancerous cell lines and primary cells. The particles were toxic to the immune cells in a dose dependent manner and impaired certain cellular functions. Primary cells were most susceptible to nanosilica induced death and, of the primary cells, phagocytes were most susceptible to its cytotoxicity. Further investigations were conducted to assess the effect of nanosilica on T cells, as there was evidence suggesting that nanosilica particles were directly interacting with these cells. Nanosilica particles 3.6 nm in diameter were found to have a significant effect on T cell function. The particles induced numerous markers of T cell activation, including CD25 and CD69 on CD4 T cells, CD8 T cells, gamma-delta T cells and NK/NKT cells, CD95 on CD4 and CD8 T cells, CD40L, FoxP3, LAP, GARP on CD4 T cells, and IFN-gamma production, but it did not induce T ce…
abstract: Humans are exposed to high levels of amorphous silica on a daily basis, via the diet and the use of cosmetic and pharmaceutical products. Amorphous silica particles (10-200 nm) have also been developed for use in biomedical applications, including as binding agents in tissue repair, drug and gene therapy delivery agents, coatings for medical contrast agents and as vaccine adjuvants. Numerous studies have already been conducted to evaluate the cellular toxicity of these silica particles but still little is known about their effects both in vitro and in vivo, especially of nanosilica particles under 10 nm in diameter. The aim of this thesis was to investigate the cellular and in vivo activity of < 10 nm diameter nanosilica particles with different properties (e.g., size and dissolution rate in dilute conditions) as it may infer upon safety after exposure via the diet and intravenous administration (biomedical applications). First, the cytotoxicity of sub-10 nm nanosilica particles, fully characterized by size, dissolution rate, zeta-potential and by NMR spectroscopy, on immune cell function was assessed using transformed and cancerous cell lines and primary cells. The particles were toxic to the immune cells in a dose dependent manner and impaired certain cellular functions. Primary cells were most susceptible to nanosilica induced death and, of the primary cells, phagocytes were most susceptible to its cytotoxicity. Further investigations were conducted to assess the effect of nanosilica on T cells, as there was evidence suggesting that nanosilica particles were directly interacting with these cells. Nanosilica particles 3.6 nm in diameter were found to have a significant effect on T cell function. The particles induced numerous markers of T cell activation, including CD25 and CD69 on CD4 T cells, CD8 T cells, gamma-delta T cells and NK/NKT cells, CD95 on CD4 and CD8 T cells, CD40L, FoxP3, LAP, GARP on CD4 T cells, and IFN-gamma production, but it did not induce T ce…
author: Vis, Bradley
language: en
keywords: T cell activation, toxicity, amorphous silica nanoparticles, synthesis, primary peripheral cells, safety
license: https://www.repository.cam.ac.uk/bitstreams/f1e1315a-327a-482a-a680-5653be9bf89e/download
license: https://www.rioxx.net/licenses/all-rights-reserved/
date published: 2018-02-07
date modified: 2026-07-24T01:33:15Z
provider: Cambridge University
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Cambridge

PropertyValue
property ID: DOI
value: 10.17863/CAM.20804