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Accelerated Neutral Atom Beam (ANAB) technology for polymer-free drug elution barrier on implantable medical devices
Accelerated Neutral Atom Beam (ANAB) technology is an accelerated particle beam gaining acceptance as a tool for nanoscale surface modification of implantable devices. ANAB is created by acceleration of neutral gas atoms with very low energies under vacuum which bombard a material surface, modifying it to a shallow depth of 2-3 nm. When ANAB is applied to the surface of a medical implant coated with organic therapeutic agent, such treatment results in formation of nanometer-thin carbon-rich scaffold on the surface of the coating. The scaffold is formed due to the difference in sputtering threshold between carbon and other atoms present in the drug molecule. Once formed, such carbon-rich layer serves as a native elution barrier for the drug, slowing down its release into the body and prolonging its therapeutic effect. Importantly, such property is achieved without use of polymer binding agents that are commonly used to create elution barriers. Polymer breakdown in traditional drug coatings has been identified as detrimental. We have demonstrated an efficient creation of drug elution barrier with ANAB technology on three different classes of drugs: titanium coated with antibiotic (kanamycin), CoCr coronary stent coated with rapamycin, and titanium coated with a growth factor (BMP-2).
Accelerated Neutral Atom Beam (ANAB) technology for improved biocompatibility of implantable medical devices
Accelerated Neutral Atom Beam (ANAB) technology is an accelerated particle beam gaining acceptance as a tool for nanoscale surface modification of implantable devices. ANAB is created by acceleration of neutral gas atoms with very low energies under vacuum which bombard a material surface, modifying it to a depth of 2-3 nm. This is a non-additive technology that results in modifications of surface topography, wettability, and surface chemistry. These modifications are understood to be important in cell-surface interactions on implantable medical devices. Controlling surface properties of biomaterials is vital in improving the biocompatibility of devices by enhancing integration and reducing bacterial attachment. When treated with ANAB, materials including polymers (PEEK, polypropylene, PTFE), and metals (titanium, CoCr, stainless steel) develop a nanotextured surface of 20-50 nm from peak to peak. Such nanotexture is known to promote tissue integration. In addition, ANAB treatment increases surface hydrophilicity, another factor favorable for biocompatibility. Finally, ANAB treated surfaces demonstrate bacterial inhibition, reducing bacterial attachment to the surface and preventing colonization. This has been observed for many common gram-positive and gram-negative pathogens. FDA approvals have been recently granted to PEEK spinal fusion devices treated by ANAB; other devices are under evaluation.
