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Biomineralization Kinetics

  1. Dec 27, 2007 #1
    Good afternoon everyone. I hope everyone is enjoying the holidays.

    I'm interested in studying the crystallization kinetics of several different calcium phosphate phases nucleating and growing on polymeric scaffold materials. The scaffolds are meant for use in different tissue engineering applications, specifically bone regeneration. I have made non-porous discs of poly(lactic acid) filled with a bioactive filler. The discs are immersed in simulated body fluid (SBF) which is simply water prepared with ion concentrations like those found in the human body (Ca, Na, etc.). Different calcium phosphate phases grow on the surface of the scaffold at varying rates depending on a variety of system parameters (filler loading, polymer matrix material, SBF ion concentrations, surface groups, etc).

    I am trying to investigate those parameters by coorelating them to the crystallization kinetics of the different phases. I can target a specific phase of interest (the one argued to be most influential for stem cell differentiation) and work with that, but I'm encountering some problems. My main issue is that the mineral phases grow very unevenly on the surface and it is difficult to pick samples that would produce reasonable quantitative results. How would I test the crystal growth on surface over time without having to scrape off all the mineral and start over? I am looking for the mass of each (or one) phase accumulated on the surface over time without destroying each sample every time I have to take a measurement.

    I am new to crystallization studies of this nature. I have some background on classic crystallization theories in general, but I've never experimentally worked on any. Any suggestions on how I should proceed? What experimental methods should I look into?

    Any input is much appreciated. I apologize if I missed some important details in an attempt to keep it short. Just let me know.

  2. jcsd
  3. Dec 31, 2007 #2
    I can't imagine bio-mineralisation kinetics being any different from general kinetics of reactions. The factor that one might have to consider is the added catalytic effects of biological cells that might enhance the reaction rates.
  4. Jan 15, 2008 #3


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    I was once involved in a project that studied the mineralization of dentin. I had the same problem. I had to destroy at least a portion of my sample to get any data. I looked at the mineralization by electron microscopy using the backscatter image. Fancy analysis of the backscatter image was used to determine the extent of mineralization. I didn't do the analysis myself so I can't help with that, I'm afraid.

    I did come across some work in the dental literature that looked at the reflected near IR intensity which was correlated with extent of mineralization. I went so far as to order the NIR diodes but didn't go any further since I didn't have any standardized samples to calibrate the thing. I can't remember the Authors or the Journal but you should be able to find it by searching on "mineralization dentin NIR diode". Can't be many people doing it that way so it should be a short list of publications.
  5. Jan 15, 2008 #4
    Thank you very much. I will look into it.
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