User:Amirah

Initial ideas

• Build a self assembling and degradable scaffold
  • Self assembly would get rid of the use of extraneous material to form proper bonds.
  • If the material is degrabale, it can degrade leaving the scaffold behind.
• Find coating to cover degradable scaffold that can select for viruses or cells that excrete scaffold material (collagen, calcuim bicarbonate etc.)
• Find coating to bind proteins needed to assemble outer scaffold layer.
  • Coating must not alter assembly or binding of scaffold
  • Coating must be very selective for protein or cells needed to form outer non-degradable layer of scaffolding.

Experimental Implementation ideas

• Use DNA as scaffold.
  • DNA is degradable
  • DNA has the ability to be self assembled into 2D structures (Rothemund), and 3D structures (Zhang)
• Build 3D structures from adaptaion of 'raster fill method' (Rothemund)
• Try the assembly of bone structures
  • Use bone morphogenic proteins, BMPs (Hosseinkhani)
  • Use mesenchymal stem cells, MSC (Hoseeinkhani)
• Improved cell/protein seeding method onto DNA scaffold
  • RGD utilized to increase cell adhesion to 3-D scaffolds
    • RGD-modified poly(L-lactic acid)
    • Use oscillatory flow perfusion instead of static perfusion
  • Electrostatic coating of DNA bipolymer (Green)

Papers

• DNA Folding
  • Rothemund P.W.K. 2006. Folding DNA to create nanoscale shapes and patterns. Nature. 440:297-302
  • Zhang Y., Seeman, N.C. 1994. The construction of a DNA truncated octahedron. J. Am. Chem. Soc. 116: 1661-1669
  • Mirkin C. A. 2000. Programming the assembly of two- and three-dimensional architectures with DNA and nanoscale inorganic building blocks.Inorg. Chem. 11: 2258-2272
• Exploration of 3-D scaffold usages and seeding abilities
  • Hosseinkhani H., Yamamoto M., Inatsugu Y., Hiraoka Y., Inoue S., Shimokawa H., Tabata Y. 2006. Enhanced ectopic bone formation using a combination of plasmid DNA impregnation into 3-D scaffold and bioreactor perfusion culture. Biomaterials. 27: 1387-1398
  • Francoli S. E, Martin I., Sie C. P., Hagg R., Tommasini R., Candrian C., Heberer M., Barbero A. 2007. Growth FActors for Clinical-Scale Expansion of Human Articular Chondrocytes: Relevance for Automated Bioreactor Systems. 13: tentative
  • Alvarez-Barreto, J. F., Sikavitsas, V. I. 2007. Improved Mesenchymal Stem Cell Seeding on RGD-Modified Poly(L-lactic acid) Scaffolds using Flow Perfusion. Macromol. Biosci. 5: 579-588.
• DNA nanoparticle seeding technology
  • Green, J. J., Chiu E., Leshchiner, E. S., Shi J., Langer R., Anderson D. G.2007. Electrostatic ligand coatings of nanoparticles enable ligand-specific gene delivery to human primary cells.Nano Lett. 4: 874-879.

Module 4 tables

	Surface display of scFv fusion?		Binding to gold?
	Glucose	Galactose	Glucose	Galactose
pCT-CON	N	Y	N	N
pAu1	N	Y	N	Y

	Temperature	# colonies
pCT-CON	30	0
pCT-CON	25	0
pAu1	30	400
pAu1	25	280