| The cytotoxicity of water-soluble and water-suspendable nanoparticles is a sensitive function of their surface derivatization or surface coating, particle size or specific surface area, and crystalline phase (for nanocrystals). In many different human cell lines, the cytotoxicity of a nanomaterial has been shown to change up to 8 orders of magnitude with relatively minor alterations in its structure. Cellular viability was determined through live/dead staining and LDH release. If the nanomaterial was deemed cytotoxic, further biochemical endpoints were tested. In almost all cases, when the nanoparticles were brought into the aqueous phase reactive species were formed. Ex vivo chemiluminescent analysis qualitatively assessed the presence of RS, and evaluated the effect of choice of solvent, suspension agitation, and light exposure. Liquid atomic force microscopy (AFM) was utilized to examine the interaction of nanomaterials with artificial membranes, illustrating the use of in situ AFM to directly observe the interactions of a model nanoparticle with a model cell membrane. By using in vitro, ex vivo, and in situ techniques, this work demonstrates both a strategy for enhancing the toxicity of nanomaterials for certain applications such as cancer therapeutics or bactericides, as well as a remediation for the possible unwarranted biological effects of nanoparticles. |
