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Biomedical subjects

Hongmei Huang

Publications and source records attributed to Hongmei Huang.

4 recordsLinked to original sources
PubMed2006

Magnetically assisted and accelerated self-assembly of strawberry-like nano/microparticles.

Precisely controlling multiple components of functional materials with well-defined shapes and dimensions on the micro/nanometer scale promises to provide new electronic, magnetic, mechanical, and optical properties for novel sensors, circuits, and other materials application. Here for the first time we introduce a novel method to reliably pattern strawberry-like microspheres by employing magnetically directed and accelerated self-assembly of nano/microparticles in aqueous solution, without the use of a template (such as molds or grooves). The results show that 100-1000 nm paramagnetic "decorating particles" rapidly self-assembled onto the surface of fluorescent 4-5 mum spherical magnetized "core particles", producing strawberry-like particles with stable and precisely arranged microstructures. Magnetic CrO2 nanorods, approximately 60 nm in diameter and 300 nm long, attached to the nonplanar surface of the 4-5 microm polystyrene core microspheres, serve as nanometer magnetic traps, so as to attract and confine paramagnetic decorating particles. The ease and speed, with which these particles can be fabricated with the aid of magnetic force, and the flexibility to tailor their chemical and physical properties through the choice of decorating particles, should facilitate their use for practical application in materials science, biology, and technology.

Algorithms↗
PubMed2004

Monitoring molecular beacon/DNA interactions using atomic force microscopy.

The molecular beacon (MB) is a new fluorescence probe containing a single-stranded oligonucleotide with a probe sequence embedded in complementary sequences that form a hairpin stem. Due to the inherent fluorescent signal transduction mechanism, an MB functions as a sensitive probe with a high signal-to-background ratio for real-time monitoring and provides a variety of exciting opportunities in DNA, RNA, and protein studies. To better understand the properties of MBs, the specific interactions between MB and target DNA (complementary and one-base mismatch) have been directly investigated by atomic force microscopy. The interaction force between a linear DNA probe and the target DNA was also detected and compared to that between MB and target DNA. The results demonstrate the high specificity of the MB/target DNA compared to the linear DNA/target DNA interaction.

DNA↗
PubMed2003

DNA-dependent protein kinase inhibitors as drug candidates for the treatment of cancer.

Cancer presents a difficult challenge for oncologists, as there are few therapies that specifically target disease cells. Existing treatment strategies rely heavily on physical and chemical agents that nonspecifically affect DNA metabolism. To improve the effectiveness of these treatments, we have identified a new class of protein kinase inhibitor that targets a major DNA repair pathway. A representative of this class, 1-(2-hydroxy-4-morpholin-4-yl-phenyl)-ethanone, inhibits the DNA-dependent protein kinase (DNA-PK) and differs significantly from previously studied DNA-PK inhibitors both structurally and functionally. DNA-PK participates in the cellular response to and repair of chromosomal DNA double-strand breaks (DSBs). These new selective inhibitors recapitulate the phenotype of DNA-PK defective cell lines including those from SCID mice. These compounds directly inhibit the repair of DNA DSBs and consequently enhance the cytotoxicity of physical and chemical agents that induce DSBs but not other DNA lesions. In contrast to previously studied DNA-PK inhibitors, these compounds appear benign, exhibiting no toxic effects in the absence of DSB-inducing treatments. Most importantly, 1-(2-hydroxy-4-morpholin-4-yl-phenyl)-ethanone synergistically enhances radiation-induced tumor control in a mouse-human xenograft assay. These studies validate DNA-PK as a cancer drug target and suggest a new approach for enhancing the effects of existing cancer therapies.

Animals↗