Second Generation Drug-Eluting Stents

The best source for identifying the expected mechanism of Synex implants is the manufacturer's guidance to the surgeon (obtained from Synex.com). The following explanation is a brief description of the material (which is this?). Please note that the specific guide cited refers to a generic Synex system, not a specific Type II model, the core mechanism remains the same. This is the expected mechanism of Synex 2. After the surgeon performs a spondectomy, it measures the height of the gap created in the spine and uses this information to select which implant of a particular size to use.

As a proposal for improvement of BMS, the first generation drug eluting stent (DES) consists of a permanent nonabsorbent polymer coating for accommodating the metal scaffold and selected drugs. DES provides management and localization of drugs released from damaged blood vessels, but allergies, heart attacks, and even death are still problematic. The improved DES replaces the nonabsorbable polymeric coating with a nonthrombogenic absorbable polymeric coating. The absorbable coating serves to promote endothelialization by indicating a drug release profile and to reduce the inflammatory response during polymer degradation. These improved DESs reduced the occurrence of restenosis by releasing antiproliferative agents, but still late onset thrombosis occurred. Late-onset or late-on stent thrombosis (LST)

Review of surface modification technology for next generation shape memory polymer scaffolds Tina Govindarajan and Robin Shandas *

Porous scaffolds allow drug incorporation without the need for additional polymeric coatings that are common in drug eluting stents. Various surface modification techniques have been used to condition the surface to accommodate the drug for delivery. Long-term etching of the polymer surface can result in the formation of pores which can be used to hold drugs for topical delivery. The use of photolithography or soft lithography to make porous microparticles or nanoparticles to form pores in the surface of polymer samples or to embed polymer surfaces for drug delivery is also under investigation. Sandblasting has proven to be effective in forming porous surfaces on metal stents. The aluminum coating exposed to the acidic solution forms ceramic alumina and produces nanoscale pores on the membrane for drug delivery. Acid treatment of stainless steel stents has also successfully produced porous surfaces for drug elution.

Review of surface modification technology for next generation shape memory polymer scaffolds Tina Govindarajan and Robin Shandas *

Porous surfaces formed from carbon nanoparticles embedded in polymers have been shown to be promising as a means of local drug delivery. Likewise, a cobalt-chromium alloy stent coated with a porous carbon-carbon coating also shows potential in the field of drug elution and enhancement of cell attachment. Delivery of the drug from the pores is not limited to the surface and the study also studied the use of shape memory for loading multiple pharmaceutical ingredients into the SMP and drug elution. This is particularly true for SMP stents, since loading the SMP scaffold with the pharmaceutical composition permits sustained and local drug delivery. Although drug release can be controlled by changing the proportion of comonomer, efforts to maintain shape memory effect must also be considered.

Review of surface modification technology for next generation shape memory polymer scaffolds Tina Govindarajan and Robin Shandas *