Purification and bioactivation of 3D-printed titanium constructs for biomedical applications

Personalized, Biocompatible 3D-Printed Bone Implants

Jacek Grabarczyk, D.Sc. Eng., University Professor at the Institute of Materials Science and Engineering, Faculty of Mechanical Engineering, Lodz University of Technology, is leading a project addressing key challenges in modern regenerative medicine and implantology. Funded under the Proof of Concept action by the European Funds for a Modern Economy 2021–2027 (FENG) program and implemented by the Foundation for Polish Science (FNP), the project combines 3D printing technology with biomedical engineering to revolutionize treatment for patients requiring extensive bone reconstructions. Prof. Jacek Grabarczyk’s team is developing a technology to purify 3D-printed bone implants and coat them with a biocompatible carbon layer, aiming to eliminate the risk of complications associated with metal implant procedures. Furthermore, implants prepared in this manner ensure faster osseointegration and quicker recovery, directly improving patients' quality of life.

Today, personalized "tailor-made" implants are increasingly used in implantology. They are created using precise patient data - such as X-rays and CT scans - allowing the implants to fit the patient's unique anatomy perfectly. This approach is particularly critical when reconstructing major bone defects, such as in cancer patients who have had large sections of bone removed.

"Metal 3D printing is a technique that provides high precision and allows implants to be customized to specific defects. Implants are printed from titanium powders, which introduces the problem of residual powder particles adhering to the implant surface. These remnants present a major challenge, as they can cause the uncontrolled release of undesirable, toxic metal particles into the patient's body. To remove titanium powder residues from printed implants, we proposed a three-stage surface cleaning and modification process," says Prof. Jacek Grabarczyk.

The first step involves chemical acid etching to dissolve micrometric powder particles lingering on the implant surface. Next, plasma etching provides the surface with a suitable topography that supports tissue integration and cell growth. The implant features an openwork, porous structure reminiscent of pumice stone to maximize the contact area between the implant and the bone. This enables the bone to grow into the implant effectively and bond with it.

"The final step is coating the cleaned implant with a specialized carbon layer. Carbon is an excellent biocompatible material that creates a favorable environment for tissue integration, facilitating bone cell ingrowth through the implant. Moreover, the carbon coating acts as a protective barrier, preventing toxic metal ions from penetrating the body. As a result, implanting such purified and modified implants is safer for patients, shortens hospitalization and recovery times, and ultimately benefits both the patient and the healthcare system," emphasizes Prof. J. Grabarczyk.

This innovative three-step treatment process for personalized 3D-printed implants, designed to enhance biocompatibility, holds strong potential for patent protection. "As medical device companies increasingly turn to 3D printing for implants, the commercialization potential of this technology is substantial. Successful project outcomes could open doors to applications beyond bone implants, including dental and cranial implants, or even biocompatible joint replacements," adds Prof. Grabarczyk.

Jacek Grabarczyk, D.Sc. Eng., University Professor, has been with Lodz University of Technology since 1999. His research interests focus on biomaterials, nanotechnology, and plasma surface engineering techniques. As a member of the Institute of Materials Science and Engineering, he contributed to establishing the Nanodiam Center of Excellence. He is the author or co-author of a monograph, over 30 scientific papers, dozens of conference reports, five patents, and two industrial implementations. One of these implemented technologies—biocompatible Si-DLC coatings for bone implants—received the Siemens Research Award for pioneering industrial implementation. Prof. Jacek Grabarczyk is a member of the Polish Society for Biomaterials and a highly active academic educator. He has developed teaching content and learning outcomes for over a dozen courses across several faculties at Lodz University of Technology, and has supervised over 60 degree theses and two doctoral dissertations.