Manipulating Vivo Calcification with Injectable Hydrogels

Technology #5068

Compositions and methods for preventing calcification of hydrogels

Background: Alginate hydrogels have been used for a wide variety of tissue engineering and regenerative medicine applications due to their many desirable properties. Alginate hydrogels have favorable mass transfer properties, can be molded into specific shapes, have adjustable degradation kinetics, support a range of different cell phenotypes, may be mechanically and biochemically modified, support cell differentiation in large animal models, and may be biocompatible for delivery of cells in human trials. The most common method of incorporating bioactive molecules or cells into alginate matrices is via extrusion, where an alginate suspension is extruded through a needle to form droplets that fall into a solution that contains polyvalent cations causing alginate crosslinking. Various pre-clinical and clinical studies have reported alginate calcification, which presents a critical challenge in developing large scale applications using this hydrogel. Alginate calcification in vivo affects mass transfer in and out of the hydrogel and may prevent reabsorption and create unwanted mineralization foci within the tissue.

Technology: Inventors at Georgia Tech have developed compositions and methods of inhibiting or preventing calcification of hydrogels. More particularly, the compositions and methods having a pH lower than 7.4, forming a hydrogel by crosslinking alginate in a solution with a bisphosphonate compound, and/or forming hydrogel by crosslinking polyanionic polymer with a polyvalent cation that is not Ca2+. Bone regeneration can be accomplished by administering a hydrogel that does not encapsulate biological material that affects calcification and/or bone formation to an area of a subject’s body.

Potential Commercial Applications:

  • Bone regeneration
  • Bone formation
  • Tissue regeneration
  • Cell delivery vehicle
  • Protein delivery vehicle
  • Hard and soft tissue filler

Benefits/ Advantages:

  • Controllable: Able to control to what extent alginate hydrogels can calcify


Barbara D. Boyan - Professor Emerita - Georgia Tech Department of Biomedical Engineering

Zvi Schwartz - Professor - Georgia Tech Department of Biomedical Engineering

Hunter R. Moyer - Affiliate Researcher - Georgia Tech Department of Biomedical Engineering

Christopher S.D. Lee - Graduate Research Fellow - Georgia Tech Department of Biomedical Engineering