Vitamin-C delivery from CoCr alloy surfaces using polymer-free and polymer-based platforms for cardiovascular stent applications.
Antiproliferative drugs such as paclitaxel and sirolimus are delivered from stents to inhibit the growth of smooth muscle cells (SMCs) for preventing neointimal hyperplasia. However, these drugs delay the growth of endothelial cells (ECs) as well and cause late stent thrombosis. We recently demonstrated the use of Vitamin-C (l-ascorbic acid, l-AA) over paclitaxel and sirolimus for inhibiting SMCs growth and promoting EC growth simultaneously. In this study, we have investigated the delivery of l-AA from CoCr alloy surfaces for potential use in stents. A polymer-free phosphoric acid (PA) platform and a polymer-based poly(lactic-co-glycolic acid) (PLGA) platform were used for coating l-AA onto CoCr surfaces. For the PA platform, FTIR confirmed that the PA was coated on CoCr, while the AFM showed that the PA coating on the CoCr surface was homogeneous. The successful deposition of l-AA on PA-coated CoCr was also confirmed by FTIR. The uniform distribution of l-AA crystals on PA-coated CoCr was shown by SEM, optical profilometer, and AFM. The drug release studies showed that l-AA (276 μg/cm(2)) was burst released from the PA platform by 1 h. For the PLGA platform, SEM showed that the l-AA incorporated polymer films were smoothly and uniformly coated on CoCr. FTIR showed that l-AA was incorporated into the bulk of the PLGA film. DSC showed that the l-AA was present in an amorphous form and formed an intermolecular bonding interaction with PLGA. The drug release studies showed that l-AA was sustained released from the PLGA coated CoCr for up to 24 h. The SEM, FTIR, and DSC characterizations of samples collected post drug release shed light on the mechanism of l-AA release from PLGA coated CoCr. Thus, this study demonstrated the delivery of l-AA from biomaterial surfaces for potential applications in stents and other implantable medical devices.
Biomedical Engineering Program, The University of South Dakota , 4800 North Career Avenue, Sioux Falls, South Dakota 57107, United States.
Eagappanath
E
Thiruppathi
Gopinath
G
Mani
D000497:Alloys / Q000737:chemistry*; D001205:Ascorbic Acid / Q000008:administration & dosage* / Q000737:chemistry; D001672:Biocompatible Materials / Q000737:chemistry; D002152:Calorimetry, Differential Scanning; D002318:Cardiovascular Diseases / Q000628:therapy; D002858:Chromium Alloys / Q000737:chemistry*; D004337:Drug Carriers; D054855:Drug-Eluting Stents; D006801:Humans; D019344:Lactic Acid / Q000737:chemistry; D008422:Materials Testing; D018625:Microscopy, Atomic Force; D008855:Microscopy, Electron, Scanning; D010756:Phosphoric Acids / Q000737:chemistry; D011100:Polyglycolic Acid / Q000737:chemistry; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011108:Polymers / Q000737:chemistry*; D011474:Prosthesis Design; D011475:Prosthesis Failure; D017550:Spectroscopy, Fourier Transform Infrared; D013927:Thrombosis / Q000517:prevention & control; D013997:Time Factors
D000497:Alloys; D001672:Biocompatible Materials; D002858:Chromium Alloys; D004337:Drug Carriers; D010756:Phosphoric Acids; D011108:Polymers; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; C030242:phosphoric acid; D001205:Ascorbic Acid