Relating nanomaterial properties and microbial toxicity

Abstract

Metal and metal oxide nanoparticles are among the most commonly used nanomaterials and their potential for adversely affecting environmental systems raises concern. Complex microbial consortia underlie environmental processes, and the potential toxicity of nanoparticles to microbial systems, and the consequent impacts on trophic balances, is particularly worrisome. The diverse array of metal and metal oxides, the different sizes and shapes that can be prepared and the variety of possible surface coatings complicate assessments of toxicity. Further muddling biocidal interpretations are the diversity of microbes and their intrinsic tolerances to stresses. Here, we review a range of studies focused on nanoparticle-microbial interactions in an effort to correlate the physical-chemical properties of engineered metal and metal oxide nanoparticles to their biological response. General conclusions regarding the parent material of the nanoparticle and the nanoparticle's size and shape on potential toxicity can be made. However, the surface coating of the material, which can be altered significantly by environmental conditions, can ameliorate or promote microbial toxicity. Understanding nanoparticle transformations and how the nanoparticle surface can be designed to control toxicity represents a key area for further study. Additionally, the vast array of microbial species and the structuring of these species within communities complicate extrapolations of nanoparticle toxicity in real world settings. Ultimately, to interpret the effect and eventual fate of engineered materials in the environment, an understanding of the relationship between nanoparticle properties and responses at the molecular, cellular and community levels will be essential.

Differential Growth of and Nanoscale TiO 2 Accumulation in Tetrahymena thermophila by Direct Feeding versus Trophic Transfer from Pseudomonas aeruginosa

“…While there are various potential nanomaterial impacts on bacteria according to nanomaterial properties, as well as exposure conditions (10), many nanomaterials such as TiO 2 are observed to adsorb to cell membranes, e.g., of Escherichia coli (11) and P. aeruginosa (17). In fact, since nanomaterials are often larger than typical bacterial cell wall openings (18), external envelope adsorption may be the prevalent mode of manufactured nanomaterial association with bacteria.…”

“…Many manufactured nanomaterials (10), including TiO 2 (11) and either cadmium telluride (CdTe) (12) or cadmium selenide (CdSe) (13) quantum dots (QDs), have been shown to impact bacterial cell membranes and interfere with bacterial population growth (12,13). In experiments with planktonic Pseudomonas aeruginosa growing in the presence of CdSe QDs, cell membranes were disrupted by reactive oxygen species, resulting in QDs entering cells (13)(14)(15).…”

MR imaging and targeting of human breast cancer cells with folate decorated nanoparticles

“…[11][12][13][14] Among the different types of nanoparticles in nanomedicine, the increasing research interest on magnetic nanoparticles (MNPs) is justied by their unique magnetic and chemical properties combined with a substantial biocompatibility. [15][16][17][18][19] Besides their employment in Magnetic Resonance Imaging (MRI) [20][21][22][23] MNPs are interestingly involved in therapy as hyperthermia agents. [24][25][26][27] In particular several iron oxide nanoparticles were approved and used for the clinical practice as negative MRI Contrast Agents, (i.e.…”

Synthesis of NiO/CNTs Nanocomposite by Direct Chemical Precipitation Method for Preparation of Voltammetric Sensor in Acetaminophen Analysis

“…In some cases, to maintain the desirable properties of nanomaterials and prevent further reaction, a stabilizer should be added to enable them to resist abrasion, wear, and corrosion. The high surface area is an important key in the application of nanomaterials as catalysts and electrodes [2][3][4][5]. This property can be used to effectively improve the efficiency of electrochemical catalysts [6].…”