Injectable hydrogel uses visible light to regenerate bone, boost adhesion without grafts

Editor's Note

Researchers at Pohang University of Science & Technology (POSTECH) have pioneered a hydrogel that regenerates bone and adheres to tissue using only visible light—eliminating the need for traditional bone grafts or adhesives. As detailed in a December 2024 article from ScienceDaily, this injectable hydrogel offers a breakthrough solution to the longstanding challenges in treating bone defects, especially in aging populations. Unlike conventional bone grafts that require a mix of graft material and adhesives—and often struggle to maintain structural integrity or achieve both adhesion and regeneration—the hydrogel does both at once.

According to the article, the team, led by Professor Hyung Joon Cha and collaborators, designed a precursor hydrogel that includes alginate, mussel-inspired adhesive proteins, calcium ions, phosphonodiols, and a photoinitiator. When exposed to harmless visible light, the hydrogel undergoes cross-linking (to harden the material) and mineralization (to generate bone-building calcium phosphate) simultaneously. This coacervate-based hydrogel—immiscible in water—maintains its form and placement after injection, the outlet reports. This property is crucial in clinical settings, where injectable materials often disperse or fail to hold shape in complex tissue environments.

Animal model testing confirmed the hydrogel’s ability to adhere to femoral bone defects and deliver regenerative elements effectively. Previous approaches to light-activated bone repair struggled with multi-step preparation and weak integration of materials, resulting in short-lived or incomplete outcomes. By contrast, POSTECH’s hydrogel enables a single-step procedure that merges bone formation with tissue adhesion, boosting both surgical efficiency and therapeutic outcomes.

The article quotes Professor Cha as stating the technology represents “an innovative alternative to conventional complex treatments for bone diseases” and holds potential to “greatly advance bone tissue regeneration.” The research received funding from South Korea’s Ministry of Health and Welfare through dental and medical device R&D initiatives, showing its translational potential.