Novel polymer covered gold nanocage for smart drug delivery.Byline: ANI London, Nov 2 (ANI): Scientists at Washington University in St. Louis “Washington University” redirects here. For other uses, see Washington (disambiguation). Washington University in St. Louis is a private, coeducational, research university located in St. Louis, Missouri. have developed a smart gold nanocage covered with a polymer which can act as an effective drug delivery system. The nanocage is filled with a medicinal substance, such as a chemotherapy drug or bactericide bac·te·ri·cide or bac·te·ri·o·cide n. An agent that destroys bacteria. bac·te  ri·cid .esigned in Younan Xia's lab, the
cage releases carefully titrated ti·trate tr. & intr.v. ti·trat·ed, ti·trat·ing, ti·trates To determine the concentration of (a solution) by titration or perform the operation of titration. amounts of a drug only near the tissue that is the drug's intended target, thus maximizing the drug's beneficial effects while minimizing its side effects Side effects Effects of a proposed project on other parts of the firm. . It's actually the absorption component that the scientists exploit to open and close the nanocages. The polymer, poly(N-isopropylacrylamide), and its derivatives has what's called a critical temperature and when it reaches this temperature it undergoes a transformation called a phase change. If the temperature is lower than the critical temperature, the polymer chains are water-loving and stand out from the cage like brushes. The brushes seal the cage's pores and prevent its cargo from leaking out. On the other hand, if the temperature is above the critical temperature, the polymer chains shun water, shrink together and collapse. As they shrink, the pores of the cage open, and its contents flood out Verb 1. flood out - charge someone with too many tasks deluge, overwhelm burden, saddle, charge - impose a task upon, assign a responsibility to; "He charged her with cleaning up all the files over the weekend" . "It's a bit counter-intuitive. Typically when you go to higher temperature, a molecule will expand, but this one does the opposite," Nature quoted Xia as saying. Like everything else about this system, the polymer is tunable and the scientists can control its critical temperature by altering its composition. For medical applications, they tune the critical temperature to one right above body temperature (37 degrees Celsius) but well below 42 degrees Celsius (107 degree Fahrenheit), the temperature at which heat would begin to kill cells. The researchers loaded capsules with doxorubicin doxorubicin /doxo·ru·bi·cin/ (dok?so-roo´bi-sin) an antineoplastic antibiotic, produced by Streptomyces peucetius, which binds to DNA and inhibits nucleic acid synthesis; used as the hydrochloride salt and as a liposome-encased , a common chemotherapy drug and, triggered the drug's release with a laser, which killed breast cancer cells cells once believed to be peculiar to cancers, but now know to be epithelial cells differing in no respect from those found elsewhere in the body, and distinguished only by peculiarity of location and grouping. See also: Cancer growing in wells on a plastic plate. And finally, they loaded the capsules with an enzyme that snips open the cell walls of bacteria and used them to kill a bacterium that is a normal part of the flora of our mouths and throats. The study was published in the journal Nature Materials. (ANI) Copyright 2009 Asian News International The Asian News International (ANI) agency provides multimedia news to China and 50 bureaus in India. It covers virtually all of South Asia since its foundation and presently claims, on its official website, to be the leading South Asia-wide news agency. (ANI) - All Rights Reserved. Provided by Syndigate.info an Albawaba.com company |
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