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VERSION:2.0
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METHOD:PUBLISH
BEGIN:VEVENT
DTSTAMP:20260918T153339Z
LAST-MODIFIED:20121116T203436Z
DTSTART:20091023T160000Z
DTEND:20091023T170000Z
UID:event509@bu.edu
URL:http://physics.bu.edu/internal/events/show/509
SUMMARY:Early stage mineralization of extracellular matrix proteins probed 
	at the nanoscale by synchrotron imaging methods
DESCRIPTION:Featuring Elaine DiMasi\, NSLS\, Brookhaven National Laboratory
	\nHosted by: Ophelia Tsui\n\nPart of the Biophysics/Condensed Matter Semina
	r Series.\n\nAbstract:\nWe are studying biological mineralization and its c
	ontrol by the protein matrix that exists in tissue such as bone.  Biominera
	ls are organized over a hierarchy of length scales\, and their formation re
	mains a fascinating unsolved problem important for technology and medicine.
	\nExtracellular matrix (ECM) proteins are part of the puzzle. The proteins 
	themselves self-assemble to form structures that affect mineralization and 
	also provide feedback to mineralizing cells such as osteoblasts.   We prese
	nt a model system of ECM proteins\, which form micron-scale fibers arranged
	 in a mesh of 10 micron scale. \nUsing scanning probe microscopy to measure
	 the elastic properties\, we show that different ECM proteins thicken and s
	tiffen to different extents when mineralized in-vitro with calcium phosphat
	e.  This is evidence of mineralization\, probed at very early growth stages
	 before mineral particles can be imaged by electron microscopy or detected 
	with synchrotron x-ray diffraction.  To discover the location and atomic co
	ordination of Calcium in these early-stage mineralized ECMs\, we use soft x
	-ray transmission microscopy at the synchrotron source.  In this measuremen
	t a 50-nm soft x-ray beam is used to obtain a spatially resolved map of Ca 
	in the proteins.\n\nWe will also discuss the state of the art in synchrotro
	n imaging of biominerals\, pointing out new directions and making an appeal
	 for involvement of a larger user base – and a larger funding base!  
	Such methods can and should continue to be extended to other composite mate
	rials.
LOCATION:SCI 352\, 590 Commonwealth Avenue\, 02215
STATUS:CONFIRMED
CLASS:PUBLIC
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