Design of nanostructured hydrogel composites with functionalized helical rosette nanotubes as in situ curable orthopedic materials

POLY 501

Lijie Zhang, Lijie_zhang@brown.edu1, Sharwatie Ramsaywack2, Hicham Fenniri, hicham.fenniri@ualberta.ca2, and Thomas J. Webster, Thomas_Webster@Brown.edu3. (1) Division of engineering, Brown University, 182 Hope street, Box D, Providence, RI 02912, (2) National Institute for Nanotechnology and Department of Chemistry, University of Alberta, 11421 Saskatchewan Drive, Edmonton, AB T6G 2M9, Canada, (3) Division of Engineering and Orthopedics, Brown University, 182 Hope Street, Barus and Holley Rm 224, Providence, RI 02912
The objective of this study is to design novel bone tissue engineering alternatives specifically injectable nanostructured scaffolds based on helical rosette nanotubes (HRNs) and hydrogels (such as poly(2-hydroxyethyl methacrylate)-pHEMA) to repair bone defects and to determine osteoblast (bone forming cell) function on these novel in situ curable bone building agents. HRNs are a new type of soft organic nanotube obtained through the self-assembly of DNA base pair building blocks in water. Previous studies have shown that HRN-K1 (with lysine side chain) improved osteoblast functions when combined with hydrogel scaffolds at low concentrations (close to 0.001 mg/ml). When combined with pHEMA, such constructs can be injected in liquid form into a bone defect, cure at short times at elevated body temperatures, and potentially increase bone formation to heal the defect. Furthermore, HRNs can be easily functionalized with arginine-glycine-aspartic acid (RGD) peptide sequences. The preliminary in vitro results show that 0.01 mg/ml HRNs composites (1%, 5%, 10% molar ratio of RGD to K side chains) embedded in and coated on hydrogels improve osteoblast adhesion compared to 0.01 mg/ml HRN-K1 (without RGD) embedded in hydrogels. Higher molar ratios of RGD (10%) on HRNs further improved osteoblast adhesion on these scaffolds. In summary, considering the flexible design of HRNs and good cytocompatibilty of HRN hydrogels, the nanostructured hydrogel matrix containing different functionalized helical rosette nanotubes have the potential to serve as novel tissue engineering scaffold materials for orthopedic applications.
 

Scaffolds and Matrices for Tissue Engineering and Regenerative Medicine Applications
6:00 PM-8:00 PM, Tuesday, August 21, 2007 BCEC -- Exhibit Hall - B2, Poster

Sci-Mix
8:00 PM-10:00 PM, Monday, August 20, 2007 BCEC -- Exhibit Hall - B2, Sci-Mix

Division of Polymer Chemistry

The 234th ACS National Meeting, Boston, MA, August 19-23, 2007