UoH team develops new alloys for stronger medical implants

Hyderabad: The University of Hyderabad (UoH) researchers, along with research partners at IIT Delhi, IIT Bhubaneswar and CSIR-CECRI Karaikudi, have developed a new family of metal alloys that could make hip joints, bone plates and other medical implants stronger, safer and longer-lasting.

Most metal implants in use today are made from conventional alloys built around a single main metal. Over years inside the body, these can wear down, corrode, and release metal ions into the surrounding tissue. Many are also far stiffer than natural bone, which can cause the implant to gradually loosen, often meaning another surgery for the patient.

Instead of starting with one base metal and adding small amounts of others, the UoH-led team blended titanium (Ti), cobalt (Co) and chromium (Cr) in equal or near-equal proportions. Alloys made this way are known as multi-principal element alloys (MPEAs) as no single metal dominates, and elements work together to produce a combination of properties that none of them offers on its own, researchers said.

The new alloys combine high strength with excellent resistance to wear, which is essential for joints that move millions of times over a patient’s lifetime, they said, adding that alloys’ flexibility is a better match for human bone than conventional implant metals, significantly reducing the risk of the implant loosening.

According to researchers, the alloys showed excellent resistance to corrosion in laboratory tests using fluids that mimic conditions inside the human body. Cell studies confirmed the alloys are highly biocompatible, supporting healthy cell growth without any toxic effects.

The results showed that TiCoCr-based alloys are highly promising candidates for the next generation of medical implants: ones that last longer and are safer for patients.

The work forms part of the doctoral thesis of Mr Nanda Kishore Karnam, a doctoral student working under the supervision of Prof Koteswararao V Rajulapati, School of Engineering Sciences and Technology (SEST), University of Hyderabad. The study has been published in Advanced Healthcare Materials, a leading international peer-reviewed journal published by Wiley.