QNRF-funded researchers develop innovative and effective biodegradable materials

Every year, around 2.2 million bone grafting surgeries are performed worldwide to place new bone or replacement material as implants to aid in healing. Often a second surgery is then required to remove the implant after the fracture has healed or the desired bone growth has been achieved.

The removal of implants has long been a controversial issue. The need for a second surgery not only exposes patients to health risks but also causes them a considerable financial and psychological burden. Similarly, these surgeries also use up valuable health care resources.

Therefore, surgeons and patients around the world are increasingly using temporary orthopedic implants constructed from biodegradable materials that aid the healing process and degrade in a timely manner as the bone regrowth process completes. These implants eliminate the need for any subsequent surgeries and the associated medical, social, and economic costs.

However, their usage poses several complex challenges, ranging from problematic mechanical properties of materials to their inability to degrade in a timely manner. To tackle these challenges, a team of researchers from Texas A&M University at Qatar, led by Prof. Bilal Mansoor, conducted a research project titled, ‘Microstructure Design of Biocompatible Magnesium Alloys for Biodegradable Medical Implants — In vitro and In vivo Validation,’ (NPRP8-856-2-364; Resubmission of NPRP7-879-2-324), funded under Qatar National Research Fund’s flagship National Priorities Research Program (NPRP).

The research team decided to work with magnesium alloys as they have attracted attention as viable candidates for biodegradable orthopedic implants due to the resemblance of their physical and mechanical properties to the human cortical bone. Magnesium’s important role in maintaining healthy bones, increasing bone density, and its involvement in cellular functions such as protein synthesis makes it a perfect choice to build implants. However, while magnesium possesses adequate degradation kinetics, it lacks adequate mechanical properties and exhibits cytotoxic characteristics, making it unsuitable for use in healing bones and fractures.

According to Dr. Mansoor and his research team, the solution for this lies in altering the microstructure design of magnesium so it can be used as biodegradable implants. To achieve this, the team used unique material processing techniques that enable microstructural modifications leading to improved mechanical properties. The team was able to successfully improve the strength of the modified magnesium alloys by nearly 50% while retaining its suitable degradation profile for selected cases.

The performance, suitability, and degradation aspects of the alloy developed by Dr. Mansoor’s team were evaluated through cytotoxicity tests done in collaboration with experts from Hamad Medical Corporation and Qatar University. The tests confirmed that the alloy was not cytotoxic to normal cells. Moreover, a humane study in which the alloys were implanted in rats achieved desirable results as the bones were completely healed and new bone formation was completed within eight weeks.

This important development indicates that processed magnesium alloys with designed microstructures can be deployed therapeutically in a range of orthopedic, cardiovascular, and tissue engineering applications. Its use will not only remove the need for performing surgeries to remove implants but also eliminate the risks and economic costs attached to it.

This innovation also promises a significant societal and economic impact on the healthcare system and people of Qatar and has the potential to improve the quality of life and help heal patients around the world.