Related Hyaluronan Research & Development News:
4/23/2007 Lifecore Biomedical, Inc. announced today that it has entered into an exclusive license agreement with Cleveland Clinic to develop and commercialize hyaluronan-based products and related applications.
NOVEL Hyaluronan-based Hydrogels - Cross Linking Hydrogel Technology
The patented hyaluronan-based cross-linking hydrogel technology may be useful for products in aesthetics, cardiology, ophthalmology, orthopedics, and several other medical fields. Cleveland Clinic physicians and scientists, under the direction of Principal Inventor Anthony Calabro, Ph.D., have performed preliminary animal studies in several applications with encouraging results.
The novel hyaluronan-based hydrogels are produced through a two-step process.
The two-step process:
- Tyramine is introduced into hyaluronan (HY).
- Stable dityramine covalent cross-links are formed through an enzyme driven reaction mechanism.
Both the functional groups and the resulting cross-link structures have unique photometric properties that allow for easy evaluation of the degree of substitution and cross-linking. Importantly, the degree of substitution required is very low (4% - 6%), maintaining the native HY structure.
A benefit of the hydrogel technology is that these hydrogels can be formed under physiologic conditions. This allows for the direct inclusion of cells or bioactive agents during cross-linking, or alternatively, cross-linking directly adjacent to living tissue, maintaining cell and tissue viability.
The resulting hydrogels are optically clear with a wide range of physical properties depending on the initial HY concentration. For example, hydrogels formed from substituted HY solutions of 6.25 - 100 mg/ml display a wide spectrum of physical properties that include those of a gel, a paste, or a rubber.
The Advantages
The advantageous properties of the HY-based hydrogels may include the ability to:
- Provide easy characterization, quality control and in vivo detection
- Integrate with existing tissue matrices
- Incorporate into newly formed matrices
- Directly include cells and bioactive factors
- Maintain biocompatibility
- Control bioresorption
- Mimic the mechanical properties of normal tissues such as cartilage
- Cast easily into complicated anatomical shapes through a novel freeze/thaw technique
Hyaluronan Division Bibliography
Additional information regarding hyaluronic acid can be found in these sources:
Balazs, E.A.; T.C. Laurent; R.W. Jeanloz, Nomenclature of Hyaluronic Acid, Biochemical Journal Letters, 1986, vol. 235, pp 903.
Balazs, E.A., Physical Chemistry of Hyaluronic Acid, Federation Proceedings, 1958, vol. 17, pp 1086-1093.
Burdick, Jason A.; Chung, Cindy; Jia, Xinqiao; Randolph, Mark A.; Langer, Robert, Controlled degradation and mechanical behavior of photopolymerized hyaluronic acid networks, Biomacromolecules, 2005, vol. 6, pp 386-391.
Hu, Yongmei; Ju, Lu-Kwang, Purification of lactonic sophorolipids by crystallization, Journal of Biotechnology, 2001, vol. 87, pp 263-272.
Hwang, Jason J.; Liu, Kenneth; Stayton, Patrick S.; Hoffman, Allan S., Fabrication of crosslinked hyaluronic acid hydrogel microspheres for protein delivery, AAPS Annual Meeting 2006 in Boston, MA, 2006.
Brekke, John H.; Thacker, Kipling, Hyaluronan as a biomaterial, An Introduction to Biomaterials, 2006, pp 219-248.
Sahoo, Sujata; Chung, Cindy; Khetan, Sudhir; Burdick, Jason A.; Hyrolytically degradable hyaluronic acid hydrogels with controlled temporal structures, Biomacromolecules, 2008, epub ahead of print.