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Nanoparticles Delivering Drugs Can Kill Skin, Breast Cancer Cells
[ScienceDaily]
ScienceDaily (Dec. 24, 2008) — Researchers in Pennsylvania are reporting for the first time that nanoparticles 1/5,000 the diameter of a human hair encapsulating an experimental anticancer agent, kill human melanoma and drug-resistant breast cancer cells growing in laboratory cultures.
The discovery could lead to the development of a new generation of anti-cancer drugs that are safer and more effective than conventional chemotherapy agents, the scientists suggest.
The research is scheduled for the Dec. 10 issue of ACS' Nano Letters, a monthly journal.
In the new study, Mark Kester, James Adair and colleagues at Penn State's Hershey Medical Center and University Park campus point out that certain nanoparticles have shown promise as drug delivery vehicles. However, many of these particles will not dissolve in body fluids and are toxic to cells, making them unsuitable for drug delivery in humans. Although promising as an anti-cancer agent, ceramide also is insoluble in the blood stream making delivery to cancer cells difficult.
The scientists report a potential solution with development of calcium phosphate nanocomposite particles (CPNPs). The particles are soluble and with ceramide encapsulated with the calcium phosphate, effectively make ceramide soluble. With ceramide encapsulated inside, the CPNPs killed 95 percent of human melanoma cells and was "highly effective" against human breast cancer cells that are normally resistant to anticancer drugs, the researchers say.
ABSTRACT: Encapsulation of Organic Molecules in Calcium Phosphate Nanocomposite Particles for Intracellular Imaging and Drug Delivery
[Nano Letters]
Encapsulation of imaging agents and drugs in calcium phosphate nanoparticles (CPNPs) has potential as a nontoxic, bioresorbable vehicle for drug delivery to cells and tumors. The objectives of this study were to develop a calcium phosphate nanoparticle encapsulation system for organic dyes and therapeutic drugs so that advanced fluoresence methods could be used to assess the efficiency of drug delivery and possible mechanisms of nanoparticle bioabsorption. Highly concentrated CPNPs encapsulating a variety of organic fluorophores were successfully synthesized. Well-dispersed CPNPs encapsulating Cy3 amidite exhibited nearly a 5-fold increase in fluorescence quantum yield when compared to the free dye in PBS. FCS diffusion data and cell staining were used to show pH-dependent dissolution of the particles and cellular uptake, respectively. Furthermore, an experimental hydrophobic cell growth inhibitor, ceramide, was successfully delivered in vitro to human vascular smooth muscle cells via encapsulation in CPNPs. These studies demonstrate that CPNPs are effective carriers of dyes and drugs for bioimaging and, potentially, for therapeutic intervention.
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