Phospholipid-based multifunctional coating via layer-by-layer self-assembly for biomedical applications

As an important class of biomaterials，bionics inspired materials has been widely used in creating extracorporeal and implantable medical devices. However, specific service environment is often faced with multiple requirements rather than single function. Herein, we designed a phospholipid-based multifunctional coating with phospholipids-based polymers, type I collagen (Col-I) and Arg-Glu-Asp-Val (REDV) peptide, via layer-by-layer assembly. The successful synthesis of the polymers and the coating is proved by a series of characterization methods including Fourier transforming infrared spectra (FTIR), proton nuclear magnetic resonance (¹H NMR), ultraviolet-visible spectra (UV) and X-ray photoelectron spectroscopy (XPS), while the assembly process and quality change of the coating were monitored via quartz crystal microbalance (QCM). Besides, hydrophilicity and roughness of this coating was analyzed via water contact angle (WCA) and atomic force microscope (AFM), respectively. Finally, results from platelet adhesion, activation assay, smooth muscle cells (SMCs) and endothelial cells (ECs) cultures indicated that the multifunctional coating could strongly inhibit platelet adhesion and SMCs proliferation, hence provide practical application of the coating with good biocompatibility, especially the anticoagulant property and cell compatibility. It is expected that this coating may be used in blood-contacting fields such as cardiovascular stent or other devices in the future.

Randomized comparison of sirolimus-eluting and everolimus-eluting coronary stents in the treatment of total coronary occlusions: results from the chronic coronary occlusion treated by everolimus-eluting stent randomized trial

BACKGROUND

Patients with coronary total occlusions are at especially high risk for restenosis and new revascularizations. Sirolimus-eluting stents dramatically improved the clinical outcome of this subset of patients in randomized trials, but other drug-eluting stents, mainly the everolimus-eluting stent (currently the most frequently used stent), have not yet been evaluated in patients with coronary total occlusions. The objective was to compare the second-generation everolimus-eluting stent with the first-generation sirolimus-eluting stent in patients with coronary total occlusions.

METHODS AND RESULTS

A total of 207 patients with coronary total occlusions and estimated time since occlusion >2 weeks were randomized to everolimus- or sirolimus-eluting stent. The primary end point was in-stent late loss at 9-month angiographic follow-up (noninferiority trial). Clinical follow-up was performed at 1 and 12 months. In-stent late loss at 9 months was 0.29±0.60 versus 0.13±0.69 mm in patients allocated to sirolimus- and everolimus-eluting stent, respectively. The observed difference in in-stent late loss between both groups was -0.16 mm (95% confidence interval, 0.04 to -0.36 mm; P for noninferiority <0.01). The rate of binary angiographic restenosis was 10.8% and 9.1% in patients allocated to sirolimus- and everolimus-eluting stent, respectively (P=0.709), whereas the rate of vessel reocclusion was 3.2% and 1.1%, respectively (P=0.339). At 12 months, the rate of major adverse events was 15.9% versus 11.1% with sirolimus- and everolimus-eluting stent, respectively (P=0.335), and probable or definitive stent thrombosis occurred in 3.0% and 0.0% of patients, respectively (P=0.075).

CONCLUSIONS

In patients with coronary total occlusions, everolimus-eluting stent is as effective as sirolimus-eluting stent.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00793221.

Avoiding restenosis: is there a role for glucocorticoids in the drug-eluting stent era?

Restenosis is an important limitation of percutaneous coronary interventions (PCI). In-stent restenosis is mainly due to neointimal hyperplasia, a proliferative process modulated by inflammatory mechanisms. Numerous technical and pharmacological means have been tested to reduce restenosis rates, with frequently disappointing clinical results. Drug-eluting stents (DES) have demonstrated a high efficacy in reducing restenosis, but there are some associated problems that limit its generalized utilization. Glucocorticoids (GC), as potent anti-inflammatory agents, may exert beneficial effects on neointimal proliferation. Clinical studies with oral and intracoronary GC therapy have demonstrated reduction in restenosis rates in selected patients. Although further investigations are warranted, GC might have a potential role for restenosis prevention in selected cases.

[Intracranial atherosclerosis]

Until recently, intracranial atheromatosis was a probably underdiagnosed clinicopathological entity that was rarely studied in depth. In the last years the advance and expansion in the use of non-invasive diagnostic tools have led intracranial atheromatosis to the front page among the most prevalent causes of stroke worldwide. Important efforts have been accomplished with the aim of identifying markers of poor outcome, which, besides the underlying mechanisms of cerebral ischemia in these patients, are the most important factors on which clinical and therapeutic decisions should be based. To date, the therapeutic armamentarium is scarce and far from optimun, regarding medical and endovascular measures. In this review we address the most important aspects of the natural history and cure treatment of intracranial atheromatosis.

Improving the drug selection and development process for combination devices

Combination devices are at the interface of both pharmaceutical and medical device research. While there have been several notable successes in bringing combination devices to market there are drug selection criteria that both the pharmaceutical and medical device companies need to consider. A successful combination device creates a product that has efficacy greater than the sum of the parts. However, failure to address some aspects of the drug or biologic properties in enough detail could result in a suboptimal product, creating a challenging legacy for future iterations. This review addresses the many dimensions including opportunities and challenges of combination device development from both the device and pharmaceutical perspectives.

Meta-analysis comparing the effect of drug-eluting versus bare metal stents on risk of acute myocardial infarction during follow-up

The only clinical benefit of drug-eluting stents (DESs) over bare metal stents (BMSs) is a significant decrease in the need for new revascularization procedures. We evaluated whether DESs also decrease the incidence of myocardial infarction at midterm. We performed a meta-analysis from 25 randomized trials comparing commercially available DESs with BMSs that included 9,791 patients overall. There was no heterogeneity across the trials included (Q test for heterogeneity, p = 0.68). Of the 9,791 patients included in all the trials, 364 developed an acute myocardial infarction during follow-up (6 to 12 months). The risk of myocardial infarction was significantly lower in patients allocated to DESs (3.3% vs 4.2% in those allocated to BMSs, odds ratio 0.79, 95% confidence interval 0.64 to 0.97, p = 0.03). In conclusion, the significant decrease in angiographic restenosis associated with the use of DESs leads not only to a decreased need for subsequent revascularization procedures but also a decreased incidence of myocardial infarction during the first 12 months after stent implantation.