Identifying specific protein residues that guide surface interactions and orientation on silica nanoparticles.

We identify specific acylphosphatase (AcP) residues that interact with silica nanoparticles (SNPs) using a combined NMR spectroscopy and proteomics-mass spectrometry approach. AcP associated with 4- and 15-nm diameter SNPs through a common and specific interaction surface formed by amino acids from the two α-helices of the protein. Greater retention of native protein structure was obtained on 4-nm SNPs than on 15-nm particles, presumably due to greater surface curvature-induced protein stabilization with the smaller SNPs.

Engineering Nanomaterials for Biomedical Applications Requires Understanding the Nano-Bio Interface: A Perspective.

The promise of nanobiomaterials for diagnostic and therapeutic biomedical applications has been widely reported throughout the scientific community, and great strides have been made in those directions. And yet, the translation of nanomaterial-based therapeutics to clinical applications remains an elusive target. Many challenges have blocked the usage of nanomaterials in biomedicine, including potential toxicity, immunogenicity, and decreased efficacy.

Position-specific chemical modification and quantitative proteomics disclose protein orientation adsorbed on silica nanoparticles.

We describe a method for determining the orientation of cytochrome c, RNase A, and lysozyme on silica nanoparticles (SNPs) using chemical modification combined with proteolysis-mass spectrometry. The proteins interacted with SNPs through preferential adsorption sites, which are dependent on SNP diameter; 4 nm SNPs induce greater structural stabilization than 15 nm particles, presumably due to greater surface curvature of the former. These results suggest that nanoparticle size and protein structure influence protein orientation on SNPs.

Thrombus inducing property of atomically thin graphene oxide sheets.

Graphene oxide (GO), the new two-dimensional carbon nanomaterial, is extensively investigated for potential biomedical applications. Thus, it is pertinent to critically evaluate its untoward effects on physiology of tissue systems including blood platelets, the cells responsible for maintenance of hemostasis and thrombus formation. Here we report for the first time that atomically thin GO sheets elicited strong aggregatory response in platelets through activation of Src kinases and release of calcium from intracellular stores.

Negative regulation of fibrin polymerization and clot formation by nanoparticles of silver.

Thrombolytic therapy in acute stroke has reduced ischemia; however, it is also associated with increased incidence of intracerebral hemorrhage and expanding stroke. Platelets and fibrin are the major components of thrombi. Since fibrin is available in large concentration at lesion sites and in all types of thrombi, it is an obvious target for majority of antithrombotic therapies.

Characterization of antiplatelet properties of silver nanoparticles.

Thrombotic disorders have emerged as serious threat to society. As anticoagulant and thrombolytic therapies are usually associated with serious bleeding complications, the focus has now shifted to regulating and maintaining platelets in an inactive state. In the present study we show that nanosilver has an innate antiplatelet property and effectively prevents integrin-mediated platelet responses, both in vivo and in vitro, in a concentration-dependent manner.

Retracted: Characterization of enhanced antibacterial effects of novel silver nanoparticles.

In the present study, we report the preparation of silver nanoparticles in the range of 10-15 nm with increased stability and enhanced anti-bacterial potency. The morphology of the nanoparticles was characterized by transmission electron microscopy. The antibacterial effect of silver nanoparticles used in this study was found to be far more potent than that described in the earlier reports.