Abstract
It was previously discovered that the unique structure and chemistry of bacterial cellulose (BC) permits the formation of calcium-deficient hydroxyapatite (CdHAP) nanocrystallites under aqueous conditions at ambient pH and temperature. In this study, BC was chemically modified via a limited periodate oxidation reaction to render the composite degradable and thus more suitable for bone regeneration. While native BC does not degrade in mammalian systems, periodate oxidation yields dialdehyde cellulose which breaks down at physiological pH. The composite was characterized by tensile testing, X-ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy. X-ray diffraction showed that oxidized BC retains its structure and could biomimetically form CdHAP. Degradation behavior was analyzed by incubating the samples in simulated physiological fluid (pH 7.4) at 37 °C under static and dynamic conditions. The oxidized BC and oxidized BC-CdHAP composites both lost significant mass after exposure to the simulated physiological environment. Examination of the incubation solutions by UV-Vis spectrophotometric analysis demonstrated that, while native BC released only small amounts of soluble cellulose fragments, oxidized cellulose releases carbonyl containing degradation products as well as soluble cellulose fragments. By entrapping CdHAP in a degradable hydrogel carrier, this composite should elicit bone regeneration then resorb over time to be replaced by new osseous tissue.
| Original language | English |
|---|---|
| Pages (from-to) | 887-898 |
| Number of pages | 12 |
| Journal | Cellulose |
| Volume | 16 |
| Issue number | 5 |
| DOIs | |
| State | Published - 2009 |
Funding
Acknowledgments S. A. Hutchens would like to acknowledge the Southern Regional Education Board, P.E.O. International, and The National Science Foundation for support. The authors would also like to acknowledge Dr. Elias Greenbaum. This research was supported by funding from Oak Ridge National Laboratory’s (ORNL) Technology Transfer and Economic Development Maturation Funding Program. Research at ORNL High Temperature Materials Laboratory (HTML) was sponsored by the Assistant Secretary for Energy Efficiency and Renewable Energy, Office of FreedomCAR and Vehicle Technologies, US Department of Energy. ORNL is managed by UT-Battelle, LLC, for the US Department of Energy under contract number DE-AC05-00OR22725. This work was sponsored by a contractor of the US Government under contract DE-AC05-00OR22725. Accordingly, the US Government retains a nonexclusive, royalty-free license to publish or reproduce this document, or to allow others to do so, for US Government purposes.
| Funders | Funder number |
|---|---|
| Office of FreedomCar | |
| P.E.O. International | |
| National Science Foundation | |
| U.S. Department of Energy | DE-AC05-00OR22725 |
| Office of Energy Efficiency and Renewable Energy | |
| Oak Ridge National Laboratory | |
| Government of South Australia | |
| Southern Regional Education Board |
Keywords
- Bacterial cellulose
- Hydrogel
- Hydroxyapatite composite
- Oxidized
- Resorbable