Degenerative arthritis is no longer exclusive to the elderly population. According to the National Health Insurance Service report covering the years 2012 to 2022, there has been a 22.8% increase in the prevalence of degenerative arthritis among people between the ages of 20 and 30. This increase is attributed to prolonged periods of desk sitting and excessive lifting of heavy sports equipment, both of which can cause significant cartilage damage. While artificial joints are a common treatment, bacterial infections have posed challenges. However, a recent study has proposed an intriguing solution involving the use of mussels.
A collaborative research team, composed of Professor Hyung Joon Cha from the Department of Chemical Engineering and Convergence School of Science and Technology and Dr. Hyun Sun Choi from the Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH ), and Professor Yun Kee Jo of the Department of Biomedical Convergence Science and Technology at the Convergence College of Advanced Technology at Kyungpook National University has successfully developed a coating material for implants. This material, based on mussel adhesion proteins, is designed to release antibiotics in response to bacterial invasion. The research was recently published in the online edition of Biomaterialsa leading international journal in the field of biomaterials.
In implantological procedures, bacterial infections not only compromise the stability of the implant but also give rise to various complications. Furthermore, highly antibiotic-resistant bacteria often cause recurrent infections even after antibacterial treatment, requiring additional procedures. While there has been active exploration of antibiotic implant coating materials, numerous challenges have arisen, including physical damage to the material during the procedure and potential leakage of antibiotics within it.
In this research, the team focused their attention on DOPA, one of the amino acids found in mussel adhesion proteins. DOPA, crucial for the strong adhesion observed in mussels, forms powerful bonds with metal ions. Its interaction with ferrous metal ions is notable because it weakens as acidity (pH) decreases. Recognizing that bacterial invasion alters the body’s acidity, the team developed a new coating material for implants.
This material contains antibiotics under normal conditions, but in the event of bacterial infection and subsequent acidification, it releases 70 percent of the antibiotics in eight hours, effectively eliminating bacteria. In particular, the material exhibits remarkable durability, showing immediate antibacterial efficacy even during the bone regeneration phase (approximately four weeks) after the implant procedure.
The amount of antibiotics released by the material corresponds to the degree of bacterial infection and the researchers further validated the antibacterial efficacy of the coating material based on different bacterial concentrations. In particular, the bond between DOPA and iron ions showed remarkable resilience to external physical stimuli, making it resistant to abrasion and mechanical loads encountered during the implantation process.
Professor Hyung Joon Cha of POSTECH, who led the study, expressed his expectations by saying, “The immediate and sustained antimicrobial effect of the implant adhesive coating material has the potential to significantly improve the success rate of implant procedures.” Professor Yun Kee Jo from Kyungpook National University added, explaining the importance of the research: “By selectively releasing antibiotics in response to the actual need, this could represent a breakthrough technology to prevent the emergence of superbugs in the future.”
The research was carried out with the support of the Korean Health Technology R&D Project and the Dentistry Technology R&D Project of the Ministry of Health and Welfare, the Mid-Career Research Program and the Young Researchers of the Ministry of Science and ICT, and POSCO Holdings.