PubMed Health⌕ Search

Biomedical subjects

Catherine M Goodman

Publications and source records attributed to Catherine M Goodman.

6 recordsLinked to original sources
PubMed2006

DNA-binding by functionalized gold nanoparticles: mechanism and structural requirements.

A family of nanoparticles featuring surfaces of varying hydrophobicity was synthesized. The efficiency of DNA-binding was determined, demonstrating in a fivefold modulation in binding a 37-mer DNA strand. Nanoparticle-binding causes a reversible conformational change in the DNA structure, as demonstrated by circular dichroism and fluorescence experiments. Furthermore, the affinity of the nanoparticle for the DNA can be regulated by external agents, though stability of the complex is observed at relatively high ionic strengths.

Circular Dichroism↗
PubMed2004

Surfactant layering on mixed monolayer-protected gold clusters.

Positively-charged monolayer protected gold clusters (MMPCs) were mixed with sodium dodecyl sulfate (SDS). At lower SDS concentration, the initially water-soluble particles became organic-soluble while remaining discrete. Upon further addition of SDS, the particles aggregate and become water-soluble. NaCN decomposition, TEM, and DLS characterization reveal the morphology and properties of these encapsulated assemblies.

Gold Colloid↗
PubMed2004

Control of protein structure and function through surface recognition by tailored nanoparticle scaffolds.

Thioalkyl and thioalkylated oligo(ethylene glycol) (OEG) ligands with chain-end functionality were used to fabricate water-soluble CdSe nanoparticle scaffolds. Surface recognition of chymotrypsin (ChT) was achieved using these functionalized nanoparticle scaffolds, with three levels of interaction demonstrated: no interaction (OEG terminated with hydroxyl group), inhibition with denaturation (carboxylate-terminated thioalkyl ligands), and inhibition with retention of structure (carboxylate-terminated OEG). The latter process was reversible upon an increase in ionic strength, with essentially complete restoration of enzymatic activity.

Cadmium Compounds↗
PubMed2003

Reversible "irreversible" inhibition of chymotrypsin using nanoparticle receptors.

Anionically functionalized amphiphilic nanoparticles efficiently inhibit chymotrypsin through electrostatic binding followed by protein denaturation. We demonstrate the ability to disrupt this "irreversible" inhibition of chymotrypsin through modification of the nanoparticle surface using cationic surfactants. Up to 50% of original chymotrypsin activity is rescued upon long-chain surfactant addition. Dynamic light-scattering studies demonstrate that chymotrypsin is released from the nanoparticle surface. The conformation of the rescued chymotrypsin was characterized by fluorescence and fluorescence anisotropy, indicating that chymotrypsin regains a high degree of native structure upon surfactant addition.

Carboxylic Acids↗
PubMedDate not supplied

Toxicity of gold nanoparticles functionalized with cationic and anionic side chains.

The structure and properties of gold nanoparticles make them useful for a wide array of biological application. Toxicity, however, has been observed at high concentrations using these systems. MTT, hemolysis, and bacterial viability assays were used to explore differential toxicity among the cell types used, using 2 nm core particles. These studies show that cationic particles are moderately toxic, whereas anionic particles are quite nontoxic. Concentration-dependent lysis mediated by initial electrostatic binding was observed in dye release studies using lipid vesicles, providing the probable mechanism for observed toxicity with the cationic MMPCs.

Animals↗