BME PPT - Nanostructured Metallic implants.pptx

Nanostructured metallic implants are advanced materials engineered at the nanoscale to enhance the performance, biocompatibility, and longevity of implants used in medical applications. These implants can include orthopedic, dental, and cardiovascular devices, and their nanostructuring can significantly improve their mechanical and biological properties.

1. 9 Nanostructured Metallic Implants Dr. D. Sudar vizhi , Assistant Professor ( Sl.G ), Department of Biomedical Engineering

2. NANOSTRUCTURED METALLIC IMPLANTS Metals with grain sizes below one micron are known as nanostructured metals and typically consist of crystalline or quasicrystalline particles/grains with sizes ranging from 1 to 100 nm.

3. NANOSTRUCTURED METALLIC IMPLANTS Bone is a nanophase material composed of collagen protein that has nanometer features, and nanophase hydroxyapatite . Similar to collagen, the other proteins of the extracellular matrix of the bone also possess features such as size, folding, and patterns at the nanoscale . This suggests that osteoblasts (bone-forming cells) are adapted to features at the nanoscale and hence, a nanostructured implant can promote new bone formation.

4. NANOSTRUCTURED METALLIC IMPLANTS Reduction in grain size of the material from conventional micron size to nanometer size is also accompanied by changes in the properties, such as Increased number of grain boundaries Increase of grain boundary volume Higher surface area Higher surface roughness Higher wettability characterized by lower contact angles

5. NANOSTRUCTURED METALLIC IMPLANTS The increase in the wettability and other surface features, in particular the high surface roughness, enhances the adsorption of proteins on the implant from bone marrow, blood, and other tissues. The initial adsorption of proteins, which mediate the cell attachment, enhances the osteoblast functions on the implant surface, and leads to the earlier integration of the implant with the tissue.

6. NANOSTRUCTURED METALLIC IMPLANTS The effects of nanophase metallic materials on cellular functions have been studied. The osteoblast cells were seeded on pure Ti, Ti6Al4Mo and Co28Cr6Mo compacts. The compacts were formed from their respective metallic particulates of either submicron or nanosize (largest size < 2.5 μm ) particulates and conventional micron size (smallest size > 7.5 μm ) particulates by compression at room temperature. Interestingly, the osteoblast attachment is more on Ti compared to Ti6Al4Mo and Co28Cr6Mo nanophases , but the net effect is nearly the same on all three metallic system, which have different compositions and elements.

7. GOLD NANOPARTICLES Gold nanoparticles strongly absorb light in the near-infrared (800–200 nm) region, while both blood and soft tissues are highly transparent in this region. So, by shining a laser light, the gold particles can be selectively heated if embedded in soft tissues. Thus, gold nanoparticles –laser light interaction can be used to perform a variety of biomedical applications, from local treatments to emit signals for imaging. For example, they can be tuned to destroy cancer tumors by local heating.

8. GOLD NANOPARTICLES They can be modified by attaching a range of biomolecules such as antibodies, and targeted to specific tissue or tumors. Also, they can be adopted to carry drugs, genes, or even cradle restorative stem cells. For example, they can be used for the treatment of cancer either by targeting them to attach to the cancer to locate by imaging techniques to destroy the cancer by selective local heating nor delivery of drugs with laser. Alternatively, they are used to locate the damaged areas on arteries and then deliver stem cells to build new blood vessel.

9. GOLD NANOPARTICLES Biologically active molecular networks consisting of phage (viruses that infect only bacteria) directly assembled with gold nanoparticles , have been fabricated recently to build a matrix that can support stem cells. These networks have both the physical and biological features within a single entity and can be used as biological sensors, cell-targeting agents, and as scaffolds to grow needed tissue in vitro or in vivo.

10. TITANIUM NANOPARTICLES Nanostructured titanium with very low elastic modulus, but with very high strength, is also commercially available. Using the high strength titanium, it is now possible to design hollow implants similar to bone, including mechanical properties.