Kidney Stone Crystallization
Scanning electron microscopy images of calcium oxalate monohydrate crystals demonstrating how inhibitors affect crystal shape.Copyright 2014 American Chemical Society. Reprinted with permission from Farmanesh, Sahar, Sriram Ramamoorthy, Jihae Chung, et al. "Specificity of Growth Inhibitors and their Cooperative Effects in Calcium Oxalate Monohydrate Crystallization." Journal of the American Chemical Society. January 1, 2014, Vol. 136, No. 1, pp 367-376. (Figure 3 on page 371.) http://pubs.acs.org/doi/abs/10.1021/ja410623q
Students learn how crystallization and inhibition occur by examining calcium oxalate crystals with and without inhibitors that are capable of altering crystallization. Kidney stones are composed of calcium oxalate crystals, and engineers and doctors experiment with these crystals to determine how growth is affected when a potential drug is introduced. Students play the role of engineers by trying to determine which inhibitor would be the best for blocking crystallization.
Crystals are present in many forms in the human body, and some can cause damage. Kidney stones form when the concentration of certain ions reaches high levels of supersaturation, forming crystals that block waste from exiting the body. The body naturally attempts to inhibit crystallization with other ions, however more help is necessary in most cases. Biomedical and chemical engineers and doctors design drugs to inhibit crystallization and prevent future blockages.
After this activity, students should be able to:
- Identify which inhibitor is more effective.
- Explain why one molecule is more likely to inhibit than another.
- Identify to which face an inhibitor binds.