NanoTechnology in orthopaedics

Nanotechnology is defined as the “Production and manipulation of material on a scale of < 100 nm and integration of this nanomaterial in a microscopic and macroscopic system“.

Nanoparticles differ from large particles in applying the classical law of physics

Composed of grain size much much smaller than conventional particle but have some basic atomic structure

The behavior of nanoparticles is explained by Quantum Physics, not by classical mechanics

If grain size decrease: So increases the surface area

Examples:

The volume of 1 cm3 (filled with 1μm3) has a total surface of 6 m²

The volume of 1 cm3 (filled with 1nm3) has a total surface of 6000 m²

So reducing the grain size of orthopedics implant from μm³ to nm³ increases surface area by a factor of 1000

Nanotechnology is a transformation technology of this century

• When biomaterials are introduced into the human body, the interaction between the surface of the biomaterial and the surrounding base and soft tissue is critical to differentiation and osseointegration
• Mesenchymal stem cells are one of the first cell types involved when nanophase biomaterial is introduced into the cellular environment = Improves osteointegration by MIMICKING CELL SURFACE TOPOGRAPHY
• This is by differentiation of mesenchymal stem cell
• Adsorption of extracellular adhesion molecules for osteoblastic function

Various nonstructural materials have shown to enhance osteoblast function:

1. Nanoceramics
2. Aluminum oxide
3. Titanium dioxide
4. Carbon
5. Selenium
6. Titanium alloy
7. Cobalt chrome alloy
8. Nanocrystalline diamond

Orthopedics Applications

• Reduce the risk of implant failure by improving osteointegration
  • Modern implants have a smooth implant surface at the nanometric level, a smooth surface: Induce fibrous tissue, in contrast, nanomaterial has a rough surface: Increases osteoblast, decreases fibroblast)
• Nanocrystalline hydroxyapatite (HA): Bone defect filler
• Nanocomposite scaffolds:
  • Composed of Type I collagen and nanostructure HA used to fill the osteochondral defect
• Nanophase selenium and applied to titanium orthopedics implant
  • Inhibit the growth of malignant osteoblast
• Nanophase silver
  • Incorporated with the surface of titanium implants have a powerful antibacterial and antiadhesive effect: Last up to 30 days
• Peripheral Nerve injury
  • Nanophase silver-impregnated Type I collagen scaffold significant increases the quantity of adsorbed protein critical to nerve healing:- And significant reduces the time to nerve regeneration
• Nanophase gold
  • Excellent drug delivery system
  • In tendinopathy when given NSAIDs
• Biodegradable polypeptide nanofilm coating on total joint prosthesis the delivery of cefazolin into stimulated TJR environment and observed reduction of bacterial load.

See also: Robotic Surgery in Orthopedics