A research team has created a pioneering injectable hydrogel for bone regeneration, overcoming the shortcomings of standard bone grafts and adhesion techniques.
The team, led by Professor Hyung Joon Cha from POSTECH’s Department of Chemical Engineering and the Graduate School of Convergence Science and Technology with an emphasis on Medical Science, along with Dr. Jinyoung Yun and Integrated Program student Hyun Taek Woo from the same department, has invented a unique injectable adhesive hydrogel aimed at regenerating bone. This innovative hydrogel uses safe visible light to enable cross-linking and mineralization at the same time, eliminating the need for traditional bone grafts. Their groundbreaking findings were recently published online in Biomaterials.
Bone defects can occur due to various reasons such as injuries, infections, or congenital issues, and are becoming increasingly prevalent in aging populations. Traditional treatment methods typically rely on bone grafts paired with serum or bioadhesives to repair these defects. However, current injectable hydrogels struggle to maintain their shape after insertion in the body and have insufficient adhesive strength. Furthermore, traditional approaches that use bone grafts along with adhesive materials often fail to achieve both effective “bone regeneration” and “adhesion” simultaneously.
The POSTECH research team has presented an innovative system that overcomes these challenges. Their novel hydrogel utilizes visible light, which is safe for humans, to trigger cross-linking, allowing the primary materials in the hydrogel to bond and solidify, while also fostering mineralization, which is the formation of bone-building minerals like calcium and phosphate within the hydrogel. Previous studies had explored similar uses of light but faced issues such as needing to separately prepare and mix the bone grafts and adhesives along with inadequate bonding of the main components, which tended to degrade over time.
The new hydrogel precursor includes alginate (a natural polysaccharide sourced from brown algae), mussel adhesive proteins containing RGD peptides, calcium ions, phosphonodiols, and a photoinitiator. The formulation, based on coacervation and immiscible in water, assures that the hydrogel holds its shape and position post-injection. When exposed to visible light, cross-linking takes place, and amorphous calcium phosphate—used as a bone graft material—is concurrently generated. This approach negates the need for individual bone grafts or adhesives, allowing the hydrogel to effectively promote both bone regeneration and adhesion.
In tests involving animal models with femoral bone defects, the hydrogel was successfully injected, adhered accurately, and efficiently delivered the necessary elements for bone regeneration.
Professor Cha remarked, “The injectable hydrogel system for bone regeneration created by our team stands as a promising alternative to traditional and complicated treatments for bone diseases, significantly advancing the technology for bone tissue regeneration.”
This research has received support from the Ministry of Health and Welfare’s Dental Medical Technology Research and Development Project and the Integrated End-to-End Medical Device R&D Project.
