Nanotechnology

Engineering the Future

By Allyson Clark

Smart Medicine

Aspirin• Inhibits the enzyme cyclooxygenase 2 (COX-2) so the brain

does not receive a signal interpreted as pain• Nonselective and goes throughout the body, not just the

area harmed

http://easydiagnosis.com/articles/images/aspirin.jpg

http://www.greatbigstuff.com/prodpics/aspirin-blank.jpg

Smart Medicine• Goal:

– Create a system of drug delivery that delivers any drug at the right time in the right amount

– target only malignant cells and not affect healthy tissue

• How?– Nanoshells– Hydrogels– Nanoparticles– Magnetic herding– Drug releasing, tube, and cell chambers

http://www.fh.huji.ac.il/~roib/coreshell_files/image002.gif

http://www.materials.qmul.ac.uk/postgrad/images/high-m-hydrogel.jpg

hydrogel

nanoshell

Nanoshells• Beads that are three millionths of an inch wide with an outer

metal wall and an inner silicon core• Has the ability to absorb or scatter specific wavelengths of

light• Can convert light to heat and “cook” harmful cells• Can trigger drug delivery devices

http://nano.cancer.gov/resource_center/nanotech_nanoshells.asp

Hydrogels• 3D highly hydrophilic network that can absorb

compounds• Expands in water but does not dissolve• Can control the rate at which it releases drugs

http://www.chem.stevens.edu/content_images/porous_hydrogel.gif

Electronic microscopy view of porous hydrogel.

Magnetic Herding• Manipulates colloidal objects• Biology is mostly composed of colloidal material,

things larger than 10 billionths of a meter that don’t settle

• Very few things in nature are magnetically susceptible

http://www.pnas.org/cgi/content/full/102/25/8860/FIG3

Bead transport under fields rotating out-of-plane.

Copyright ©2005 by the National Academy of Sciences PNAT

Yellen, Benjamin B. et al. (2005) Proc. Natl. Acad. Sci. USA 102, 8860-8864

Fig. 1. Bead levitation and microtweezing by magnetic traps

Nanoparticles• Drugs can be linked to nanoparticles• Nanoparticles can store pharmaceutical agents and release

them at the desired target• Allows us to see cells and molecules conventional imaging

does not allow us to detect

http://nano.cancer.gov/resource_center/nano_critical.asp#why

Drug-releasing, Tube, and Cell Chambers

• Chambers have semi-permeable membranes that use diffusion to control the release rate of medicine

• Tubes release potent drugs very slowly while chambers release at fairly fast rates

• Cell chambers can be used to produce compounds, such as insulin, inside the body

http://www.nature.com/nbt/journal/v21/n10/full/nbt876.html

Drug-releasing chamber

Truly Smart Medicine?• An “ideal” drug delivery system would be able to

determine when and if a dose was needed and would deliver it automatically

• We’re not there yet, but we’re getting closer every day!

Works Cited• http://www.math.uci.edu/~cristini/publications/nanochap.pdf• http://circ.ahajournals.org/cgi/content/full/107/8/1092• http://nano.cancer.gov/resource_center/nano_critical.asp• http://www.nature.com/nbt/journal/v21/n10/full/nbt876.html• http://www2.mdanderson.org/depts/oncolog/articles/03/7-8-julaug/7-8-03

-1.html

• http://www.economist.com/printedition/displayStory.cfm?Story_ID=916725

• http://www.nature.com/materials/nanozone/news/010927/portal/011004-2.html

• http://health.howstuffworks.com/aspirin3.htm

Works Cited (cont.)• http://courses.csusm.edu/biol356bm/Powerpoints/

drug_delivery_nano.pdf• http://leeexplore.leee.org/eil5/9589/30307/01392308.pdf?

arnumber=1392308• http://www.pnas.org/cgi/content/full/102/25/8860• http://www.sciencedaily.com/releases/

2005/06/050621074514.htm• Nanoscale Technology in Biological Systems Greco, Ralph S.