BACKGROUND:  Current endovascular procedures for the treatment of vascular diseases use a number of metallic devices including guidewires, stents and coils. A popular material for these metallic devices is NiTi and CoCr. Although this material is commonly used, it has several limitations. First, the device generates friction during the installation procedure as the device rubs against the plastic catheter used during installation. A second problem is that once a metal device is placed in an artery, the patient needs to be on blood thinning medications for a long time. This problem can be mitigated by covering the device with native tissues and cells.

INNOVATION:  Researchers at UCLA have discovered a method of treating Nitinol sheets, wires, or stents that overcomes the limitations of these devices in current practice. The devices are treated with a type of light, causing them to take on super hydrophilic properties. This conversion increases the affinity between the device and vascular tissue, resulting in the acceleration of the healing process and a reduction in clotting. The hydrophilic device also demonstrates less friction during insertion or delivery.

POTENTIAL APPLICATIONS 

• Conversion of normally hydrophobic metallic materials to super hydrophilic nature
• Installation of NiTi or CrCo sheets, wires, or stents with less friction than current methods

ADVANTAGES

• Hydrophilic conversion reduces friction between device and catheter during insertion or delivery; hydrophilic properties not easily reversed
• Increased affinity between the device and vascular tissue, resulting in accelerated healing and reduced clotting

DEVELOPMENT-TO-DATE:  NiTi and CrCo samples were treated a type of light and demonstrated to convert to hydrophilic properties. After the conversion, the NiTi sheet with hydrophilic conversion showed faster endothelial migration and faster healing that the sheet without conversion.

Reference: UCLA Case No. 2008-007