Transcript Hydroxyapatite

Kyung Jae Jeong, Ph.D., Claes H. Dohlman, M.D.,
Ph.D., and Daniel S. Kohane, M.D., Ph.D.
Harvard-MIT Health Sciences and Technology,
Department of Anesthesiology, Children’s Hospital Boston, Harvard Medical School
Massachusetts Eye and Ear Infirmary, Harvard Medical School
*The authors have no financial interest in the subject matter of this poster.
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Khan et al. (2008)
Cell migration
Cell proliferation with minimal
immune response
ECM Production
Adhesion
Good biointegration will also
reduce the danger of
bacterial/fungal infection.
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Lee et al. Nature (2007)
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Lee et al. Adv. Materials (2009)
Dopamine (or DOPA) is a major
component of mussel adhesive
protein and has good adhesive
properties.
Polydopamine coating can form on
virtually all surfaces.
Polydopamine coating can further
be used to immobilize biological
molecules which contain either thiol
or amine groups at a high density.
Chemistry is very simple.
PMMA
PMMA-RGD
MTS assay on corneal epithelial
cells
Dopa-PMMA
Dopa-PMMA-RGD
Fluorescence micrographs of epithelial cells. Nucleus
(blue) and actin cytoskeleton (red)
PMMA
PMMA-RGD
MTS assay on keratocytes
Dopa-PMMA
Dopa-PMMA-RGD
1400
Keratocytes
Epithelial Cells
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Concentration of IL-6 (pg/mL)
1200
1000
800
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600
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400
200
0
PMMA
Calcium assay. on human aortic smooth muscle cells
(HASMC). Red point corresponds to polydopamine coating.
Higher fluorescence response corresponds to higher cell
contraction.
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PMMA-RGD
Dp
Dp+RGD
TCP
LPS
IL-6 concentration from the cells seeded on various
surfaces after 24 hours. TNF- α was not detected from neither
cell types.
Polydopamine coating does not release dopamine monomer (mass spectrometry)
Minimal contraction of the aortic smooth muscle cells (Calcium Flux Assay).
Not significantly high level of proinflammatory cytokines released from the cells
seeded on the polydopamine surface (ELISA, IL-6 and TNF-α).
PMMA
Dopa-PMMA
PMMA-RGD
Dopa-RGD-PMMA
A small PMMA cylinder was pressed onto
collagen gel over night to see if there is any
adhesion at the interface.
PMMA
PMMA Cylinder
Collagen Gel
Dopa-PMMA
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Polydopamine coating enhanced the proliferation of
corneal epithelial cells and keratocytes in vitro.
Polydopamine coating is not proinflammatory and is
not expected to cause vascular constriction as its
monomer would do.
SEM images show ECM secretion from all surfaces.
Both polydopamine-coated surfaces exhibited firm
adhesion to collagen gel.
Polydopamine coating may enhance the biointegration
of Boston KPro when applied to the stem of the device.