Surface engineering at the nanoscale: A way forward to improve coronary stent efficacy.

Coronary in-stent restenosis and late stent thrombosis are the two major inadequacies of vascular stents that limit its long-term efficacy. Although restenosis has been successfully inhibited through the use of the current clinical drug-eluting stent which releases antiproliferative drugs, problems of late-stent thrombosis remain a concern due to polymer hypersensitivity and delayed re-endothelialization. Thus, the field of coronary stenting demands devices having enhanced compatibility and effectiveness to endothelial cells. Nanotechnology allows for efficient modulation of surface roughness, chemistry, feature size, and drug/biologics loading, to attain the desired biological response. Hence, surface topographical modification at the nanoscale is a plausible strategy to improve stent performance by utilizing novel design schemes that incorporate nanofeatures via the use of nanostructures, particles, or fibers, with or without the use of drugs/biologics. The main intent of this review is to deliberate on the impact of nanotechnology approaches for stent design and development and the recent advancements in this field on vascular stent performance.

Health-Related Quality of Life of Coronary Artery Disease Patients under Secondary Prevention: A Cross-Sectional Survey from South India.

BACKGROUND: Health-related quality of life (HRQOL) is emerging as an important outcome among patients with documented coronary artery disease (CAD). The primary objective of this study was to report the HRQOL of CAD patients under secondary prevention-related treatment and follow-up using the 36-Item Short Form (SF-36) tool. METHODS: This was an analytical cross-sectional survey done in a hospital/clinic setting. We recruited CAD patients 30 to 80 years old with 1 to 6 years of follow-up. Patients self-reported HRQOL using SF-36. RESULTS: We recruited 1206 patients, among whom 879 (72.9%) were male. The mean age of patients was 61.3 (9.6) years. Mean (± standard deviation) scores for physical functioning, role limitations due to physical health, pain, and general health were 66.48 ± 29.41, 78.96 ± 28.01, 80.96 ± 21.15, and 51.49 ± 20.19, respectively. The scores for role limitations due to emotional problems, energy/fatigue, emotional well-being, and social functioning were 76.62 ± 28.0, 66.18 ± 23.92, 76.91 ± 20.47, and 74.49 ± 23.55. In subgroup analysis, age, sex, type of CAD, and treatment showed no significant association with any of the 8 domains of QOL. In addition, hypertension and diabetes showed no significant association with the individual domains of HRQOL. CONCLUSION: Patients with coronary artery disease under secondary prevention-related treatment have suboptimal HRQOL under both physical and mental domains. The role of demographic factors, comorbidities, disease subtypes, and treatment options in modifying HRQOL among patients with CAD appears to be minimal.

Successful Reduction of Neointimal Hyperplasia on Stainless Steel Coronary Stents by Titania Nanotexturing.

Bare metal stents (BMSs) of stainless steel (SS) were surface engineered to develop nanoscale titania topography using a combination of physical vapor deposition and thermochemical processing. The nanoleafy architecture formed on the stent surface remained stable and adherent upon repeated crimping and expansion, as well as under flow. This titania nanoengineered stent showed a preferential proliferation of endothelial cells over smooth muscle cells in vitro, which is an essential requirement for improving the in vivo endothelialization, with concurrent reduction of intimal hyperplasia. The efficacy of this surface-modified stent was assessed after implantation in rabbit iliac arteries for 8 weeks. Significant reduction in neointimal thickening and thereby in-stent restenosis with complete endothelial coverage was observed for the nanotextured stents, compared to BMSs, even without the use of any antiproliferative agents or polymers as in drug-eluting stents. Nanotexturing of stents did not induce any inflammatory response, akin to BMSs. This study thus indicates the effectiveness of a facile titania nanotopography on SS stents for coronary applications and the possibility of bringing this low-priced material back to clinics.

Transforming Nanofibers into Woven Nanotextiles for Vascular Application.

This study investigates the unique properties, fabrication technique, and vascular applications of woven nanotextiles made from low-strength nanoyarns, which are bundles of thousands of nanofibers. An innovative robotic system was developed to meticulously interweave nanoyarns in longitudinal and transverse directions, resulting in a flexible, but strong woven product. This is the only technique for producing seamless nanotextiles in tubular form from nanofibers. The porosity and the mechanical properties of nanotextiles could be substantially tuned by altering the number of nanoyarns per unit area. Investigations of the physical and biological properties of the woven nanotextile revealed remarkable and fundamental differences from its nonwoven nanofibrous form and conventional textiles. This enhancement in the material property was attributed to the multitude of hierarchically arranged nanofibers in the woven nanotextiles. This patterned woven nanotextile architecture leads to a superhydrophilic behavior in an otherwise hydrophobic material, which in turn contributed to enhanced protein adsorption and consequent cell attachment and spreading. Short-term in vivo testing was performed, which proved that the nanotextile conduit was robust, suturable, kink proof, and nonthrombogenic and could act as an efficient embolizer when deployed into an artery.