By Girish Linganna
Scientists have developed a new kind of metal mix that can be used in 3D implants for orthopaedic purposes like bones or joints. The goal of creating this alloy was to solve two major issues during surgery: bacterial infections and improved compatibility and strength.
3D implants refer to medical devices or structures that are created using three-dimensional printing technology. These implants are custom-made to fit a patient’s specific anatomy and are used in various medical fields, including orthopaedics, for the precise and personalized treatment of bone or joint conditions.
According to reports from Medical Xpress, scientists at Washington State University (WSU) have conducted laboratory tests on a new implant. This implant successfully eliminated 87 percent of bacteria that cause staph infections. Additionally, it remained strong and compatible with surrounding tissue, just like current implants in use.
~ A staph infection is a type of bacterial infection caused by the Staphylococcus bacteria. It can affect various parts of the body, leading to symptoms such as redness, swelling, pain, and pus-filled sores. Staph infections can range from mild to severe and may require treatment with antibiotics. In severe cases, if left untreated or if the infection spreads throughout the body, a staph infection can be life-threatening and may lead to death. It is important to seek medical attention promptly if you suspect a staph infection.
Currently, the implants commonly used in surgeries often result in bacterial infections. These infections often require additional surgeries to remove the implants or, in severe cases, can even lead to the amputation of limbs. However, the new metal alloy is specifically designed to prevent bacterial growth better than the ones currently in use. This reduces the likelihood of infections occurring.
The Distinguished Professor in WSU’s School of Mechanical Engineering explained that infections are a significant problem that currently lacks a solution, as implants often lack defense against infections. Instead of relying solely on drug-based infection control, the professor suggests changing the material of the implant itself to provide inherent antibacterial properties. This approach would offer a natural resistance to infections without relying on external measures.
Moreover, the new implant material is designed to be more compatible with the body and stronger compared to previous materials used in implants. This means that it provides better support to the body, reduces stress without deteriorating quickly, and seamlessly integrates with the surrounding bones for improved effectiveness.
This invention introduces an innovative implant material that not only enhances the body’s ability to combat bacterial infections but also improves compatibility and strength. This has the potential to enhance the success of orthopaedic implants and minimize complications faced by patients.
Scientists studied bacterial colonization on orthopaedic implants, manufactured Ti3Al2V alloy, and analysed alloys of Ti-Tantalum (Ta)–Copper (Cu).
~ The composition of Ti3Al2V alloy consists of titanium (Ti), aluminium (Al), and vanadium (V).
~ Ti-Tantalum (Ta) refers to an alloy that combines titanium and tantalum in its composition. This alloy is created by combining and blending the two metals in specific proportions to achieve desired properties and characteristics. The combination of titanium and tantalum can result in improved strength, corrosion resistance, and other beneficial qualities, making it suitable for various applications, including medical implants and aerospace components.
As per the study, researchers used a technique called laser powder bed fusion to fabricate a Ti3Al2V alloy.This involved combining CpTi and Ti6Al4V powders and using laser energy to fuse them together. To improve biocompatibility and add resistance against bacteria, tantalum (Ta) and copper (Cu) were included in the alloy composition. The addition of these elements enhanced the material’s ability to interact favourably with the body and reduce the risk of bacterial colonization.
~ Laser powder bed fusion is an advanced manufacturing method that utilizes a laser to selectively melt and fuse powdered materials. The process involves scanning a thin layer of powder as the laser heats and solidifies it, layer by layer, forming a solid object. This additive manufacturing technique offers precise control and allows for the creation of complex and customized structures with high accuracy.
~ The composition of a Ti3Al2V alloy involves combining two different types of titanium alloys: CpTi (commercially pure titanium) and Ti6Al4V (titanium alloyed with 6% aluminium and 4% vanadium). By mixing these two titanium alloys, the resulting alloy exhibits a combination of the desired properties of both components. This includes improved strength, corrosion resistance, and biocompatibility, making it suitable for various applications in industries such as medicine and aerospace.
In the study, the researchers examined the biological, mechanical, and tribo-biocorrosion characteristics of these alloys. They specifically looked at how well the alloys resisted bacterial infections caused by Pseudomonas aeruginosa and Staphylococcus aureus. By evaluating these properties, the researchers aimed to gain insights into the alloys’ performance and their potential for use in medical applications.
~Tribo-biocorrosion refers to the combined effect of mechanical wear (tribology) and corrosion in the presence of a biological environment. In the context of alloys used in biomedical applications, it refers to the wear-induced degradation of the material in the presence of biofluids and biological factors. This can involve the interaction between mechanical forces, corrosion processes, and biological factors, which can affect the performance and integrity of the material in biomedical settings.
~ Pseudomonas aeruginosa is a common bacterium found in various environments, including soil, water, and hospitals. It is known for its opportunistic nature and ability to cause infections, particularly in people with weakened immune systems. P. aeruginosa can lead to a range of infections, such as pneumonia, urinary tract infections, and bloodstream infections, and it is recognized as a significant threat, especially in healthcare settings.
P. aeruginosa can have detrimental effects on orthopaedic implants. When this bacterium colonizes the implant site, it can cause infections, leading to implant failure and complications. This can result in chronic infections, delayed healing, tissue damage, and loosening of the implant. Prompt detection and appropriate treatment are crucial to prevent the spread of infection and preserve the integrity and functionality of the orthopaedic implant.
After conducting their analysis, the researchers discovered that by incorporating a small amount of copper into a specific metal combination, they developed a material with remarkable antibacterial properties. Additionally, this material exhibited excellent durability and was able to withstand substantial amounts of pressure without deteriorating rapidly.
According to the study, when 3% by weight of copper (Cu) was added to the Ti3Al2V alloy, its ability to combat bacteria was significantly enhanced. This modification showed an impressive effectiveness of 78% to 86% against strains of Pseudomonas aeruginosa and Staphylococcus aureus, surpassing the performance of CpTi.
The study found that the Ti3Al2V–10Ta–3Cu alloy displayed impressive mechanical properties, such as resistance to fatigue, increased strength, and improved resistance to wear and corrosion when compared to the widely used Ti6Al4V alloy.
Additionally, experiments performed on a rat distal femur model demonstrated improved early-stage bonding between the implant and bone tissue for alloys containing 10% by weight of tantalum (Ta). This level of osseointegration surpassed what was observed with CpTi and Ti6Al4V alloys, suggesting a more favourable integration of the implant with the surrounding bone tissue.
~ “Rat distal femur” refers to the lower part of the thigh bone (femur) in rats. In this context, it typically refers to a specific area of the femur that is used as a model in research studies. Researchers often study the effects of implants or interventions on this particular region of the rat femur to understand how it may translate to similar situations in human bone tissue.
~ “Level of osseointegration” refers to the degree or extent to which an implant becomes securely integrated into surrounding bone tissue. Osseointegration is a critical factor in the success and stability of implants, particularly in orthopaedic and dental procedures. A high level of osseointegration implies a strong and stable connection between the implant and the surrounding bone, promoting long-term functional and structural integrity. It is often assessed based on factors such as bone-implant contact, bone formation around the implant, and mechanical stability.
The characteristics exhibited by the newly developed metal combination indicate that it has the potential to be a highly viable option for future load-bearing metallic implants. A respected professor at the Westinghouse school emphasized that the major benefit of this multifunctional device is its ability to not only control infections but also promote effective integration with bone tissue.
In today’s surgical field where infection is a major concern, a multifunctional device that can address both infection control and bone tissue integration is highly valuable and unparalleled.
The author is an independent Aerospace & Defence Analyst. Views expressed are personal and do not reflect the official position or policy of Financial Express Online. Reproducing this content without permission is prohibited.