To repair or replace bone tissue, surgeons sometimes graft material from another part of a patient’s skeleton onto the damaged site. But harvesting healthy replacement tissue can be as painful as it sounds and can do lasting harm to the spot from which it’s taken.
Bovine bone material is a safe and abundant alternative that avoids these complications, but it comes with its own problems, according to Hyo Jeong Kim of Pohang University of Science & Technology (POSTECH).
To avoid triggering an immune response in humans, the bone must first shed its bovine biochemistry, including removing its collagen and other structural proteins. This makes the material brittle. Substances such as cellulose gum can restore some of the lost cohesion, but these binders struggle to keep grafts anchored to bones in the blood and water of the human body.
To alleviate these problems, researchers led by Kim, POSTECH’s Hyung Joon Cha, and Sang Ho Jun of Anam Hospital turned to a biocompatible binder based on two polyelectrolytes: hyaluronic acid and positively charged adhesive proteins from mussels (Adv. Healthcare Mater. 2016, DOI: 10.1002/adhm.201601169). Bovine bone particles treated with the binder remained stable and sticky in blood and water. Furthermore, studies in rats showed that implanted material also promoted bone regeneration.
Kim reported the results Tuesday at the American Chemical Society national meeting in San Francisco during a session sponsored by the Division of Polymer Chemistry.
The work is impressive, commented Hoyong Chung, but the mussel-based adhesive itself is not new and is one of a number of emerging and promising biomedical materials. In fact, Chung recently unveiled a bioinspired adhesive with his colleagues at Florida State University (ACS Appl. Mater. Interfaces 2017, DOI: 10.1021/acsami.6b14599).
Still, he said, the POSTECH work does stand apart because of the data demonstrating bone generation. “Generally, this type of in vivo test is a very important first step toward practical clinical application.”