Promoting vascular healing using nanofibrous ticagrelor-eluting stents

Nanomedicine for Diagnosis and Treatment of Atherosclerosis

With the changing disease spectrum, atherosclerosis has become increasingly prevalent worldwide and the associated diseases have emerged as the leading cause of death. Due to their fascinating physical, chemical, and biological characteristics, nanomaterials are regarded as a promising tool to tackle enormous challenges in medicine. The emerging discipline of nanomedicine has filled a huge application gap in the atherosclerotic field, ushering a new generation of diagnosis and treatment strategies. Herein, based on the essential pathogenic contributors of atherogenesis, as well as the distinct composition/structural characteristics, synthesis strategies, and surface design of nanoplatforms, the three major application branches (nanodiagnosis, nanotherapy, and nanotheranostic) of nanomedicine in atherosclerosis are elaborated. Then, state-of-art studies containing a sequence of representative and significant achievements are summarized in detail with an emphasis on the intrinsic interaction/relationship between nanomedicines and atherosclerosis. Particularly, attention is paid to the biosafety of nanomedicines, which aims to pave the way for future clinical translation of this burgeoning field. Finally, this comprehensive review is concluded by proposing unresolved key scientific issues and sharing the vision and expectation for the future, fully elucidating the closed loop from atherogenesis to the application paradigm of nanomedicines for advancing the early achievement of clinical applications.

Recent advance in treatment of atherosclerosis: Key targets and plaque-positioned delivery strategies

Atherosclerosis, a chronic inflammatory disease of vascular wall, is a progressive pathophysiological process with lipids oxidation/depositing initiation and innate/adaptive immune responses. The coordination of multi systems covering oxidative stress, dysfunctional endothelium, diseased lipid uptake, cell apoptosis, thrombotic and pro-inflammatory responding as well as switched SMCs contributes to plaque growth. In this circumstance, inevitably, targeting these processes is considered to be effective for treating atherosclerosis. Arriving, retention and working of payload candidates mediated by targets in lesion direct ultimate therapeutic outcomes. Accumulating a series of scientific studies and clinical practice in the past decades, lesion homing delivery strategies including stent/balloon/nanoparticle-based transportation worked as the potent promotor to ensure a therapeutic effect. The objective of this review is to achieve a very brief summary about the effective therapeutic methods cooperating specifical targets and positioning-delivery strategies in atherosclerosis for better outcomes.

First Experience of Three Neurovascular Centers With the p64MW-HPC, a Low-Profile Flow Diverter Designed for Proximal Cerebral Vessels With Antithrombotic Coating

Background: In the last decade, flow diversion (FD) has been established as hemodynamic treatment for cerebral aneurysms arising from proximal and distal cerebral arteries. However, two significant limitations remain—the need for 0.027” microcatheters required for delivery of most flow diverting stents (FDS), and long-term dual anti-platelet therapy (DAPT) in order to prevent FDS-associated thromboembolism, at the cost of increasing the risk for hemorrhage. This study reports the experience of three neurovascular centers with the p64MW-HPC, a FDS with anti-thrombotic coating that is implantable via a 0.021” microcatheter.

Materials and methods: Three neurovascular centers contributed to this retrospective analysis of patients that had been treated with the p64MW-HPC between March 2020 and March 2021. Clinical data, aneurysm characteristics, and follow-up results, including procedural and post-procedural complications, were recorded. The hemodynamic effect was assessed using the O'Kelly–Marotta Scale (OKM).

Results: Thirty-two patients (22 female, mean age 57.1 years) with 33 aneurysms (27 anterior circulation and six posterior circulation) were successfully treated with the p64MW-HPC. In 30/32 patients (93.75%), aneurysmal perfusion was significantly reduced immediately post implantation. Follow-up imaging was available for 23 aneurysms. Delayed aneurysm perfusion (OKM A3: 8.7%), reduction in aneurysm size (OKM B1-3: 26.1%), or sufficient separation from the parent vessel (OKM C1-3 and D1: 65.2%) was demonstrated at the last available follow-up after a mean of 5.9 months. In two cases, device thrombosis after early discontinuation of DAPT occurred. One delayed rupture caused a caroticocavernous fistula. The complications were treated sufficiently and all patients recovered without permanent significant morbidity.

Conclusion: Treatment with the p64MW-HPC is safe and feasible and achieves good early aneurysm occlusion rates in the proximal intracranial circulation, which are comparable to those of well-established FDS. Sudden interruption of DAPT in the early post-interventional phase can cause in-stent thrombosis despite the HPC surface modification. Deliverability via the 0.021” microcatheter facilitates treatment in challenging vascular anatomies.

The role of P2Y12 receptor inhibition in ischemic stroke on microglia, platelets and vascular smooth muscle cells

P2Y12 receptors on platelets have long been the main target of antiplatelet drugs. However, a growing number of studies have revealed that P2Y12 receptor activation on microglia and vascular smooth muscle cells (VSMCs) also aggravates ischemic stroke injury. The proliferation and migration of VSMCs in the vascular wall have important influence on the early lesion of atherosclerosis, which may lead to the origin of cerebral ischemic attack of atherosclerosis. Blockage of cellular P2Y12 receptors could inhibit microglial activation, block formation of platelet-leukocyte aggregates, reduce proinflammatory cytokine levels and suppress migration and proliferation of VSMCs, implying that apart from anti-thrombotic effect, P2Y12 inhibitors have additional neuroprotective, anti-inflammatory and anti-atherosclerotic therapeutic benefits against ischemic stroke. In this review, we will summarize recent advances in studies on P2Y12 receptors and emphatically introduce their significance in microglia, platelets and VSMCs after ischemic stroke, discussing how to exert the beneficial effects of P2Y12 inhibition.

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.

The pleiotropic effects of antithrombotic drugs in the metabolic-cardiovascular-neurodegenerative disease continuum: impact beyond reduced clotting

Antithrombotic drugs are widely used for primary and secondary prevention, as well as treatment of many cardiovascular disorders. Over the past few decades, major advances in the pharmacology of these agents have been made with the introduction of new drug classes as novel therapeutic options. Accumulating evidence indicates that the beneficial outcomes of some of these antithrombotic agents are not solely related to their ability to reduce thrombosis. Here, we review the evidence supporting established and potential pleiotropic effects of four novel classes of antithrombotic drugs, adenosine diphosphate (ADP) P2Y12-receptor antagonists, Glycoprotein IIb/IIIa receptor Inhibitors, and Direct Oral Anticoagulants (DOACs), which include Direct Factor Xa (FXa) and Direct Thrombin Inhibitors. Specifically, we discuss the molecular evidence supporting such pleiotropic effects in the context of cardiovascular disease (CVD) including endothelial dysfunction (ED), atherosclerosis, cardiac injury, stroke, and arrhythmia. Importantly, we highlight the role of DOACs in mitigating metabolic dysfunction-associated cardiovascular derangements. We also postulate that DOACs modulate perivascular adipose tissue inflammation and thus, may reverse cardiovascular dysfunction early in the course of the metabolic syndrome. In this regard, we argue that some antithrombotic agents can reverse the neurovascular damage in Alzheimer's and Parkinson's brain and following traumatic brain injury (TBI). Overall, we attempt to provide an up-to-date comprehensive review of the less-recognized, beneficial molecular aspects of antithrombotic therapy beyond reduced thrombus formation. We also make a solid argument for the need of further mechanistic analysis of the pleiotropic effects of antithrombotic drugs in the future.

Recent advances in nanomaterials for therapy and diagnosis for atherosclerosis

Atherosclerosis is a chronic inflammatory disease driven by lipid accumulation in arteries, leading to narrowing and thrombosis. It affects the heart, brain, and peripheral vessels and is the leading cause of mortality in the United States. Researchers have strived to design nanomaterials of various functions, ranging from non-invasive imaging contrast agents, targeted therapeutic delivery systems to multifunctional nanoagents able to target, diagnose, and treat atherosclerosis. Therefore, this review aims to summarize recent progress (2017-now) in the development of nanomaterials and their applications to improve atherosclerosis diagnosis and therapy during the preclinical and clinical stages of the disease.

Nanostructured Titanium for Improved Endothelial Biocompatibility and Reduced Platelet Adhesion in Stent Applications

Although coronary stents have improved the early and long-term consequences of arterial lesions, the prevention of restenosis and late stent thrombosis is key to prevent a new obstruction of the vessel. Here we aimed at improving the tissue response to stents through surface modification. For that purpose, we used two different approaches, the use of nanostructuration by electrochemical anodization and the addition of a quercitrin (QR) coating to the Ti surface. Four surfaces (Ti, NN, TiQR and NNQR) were characterized by atomic force microscopy, scanning electronic microscopy and contact angle analysis and QR content was evaluated by fluorescent staining. Cell adhesion, cytotoxicity, metabolic activity and nitric oxide (NO) production was evaluated on primary human umbilical cord endothelial cells (HUVECs). Platelet adhesion, hemolysis rate and Staphylococcus epidermidis CECT 4184 adhesion at 30 min were analyzed. Nanostructuration induced an increase on surface roughness, and QR coating decreased the contact angle. All surfaces were biocompatible, with no hemolysis rate and lower platelet adhesion was found in NN surfaces. Finally, S. epidermidis adhesion was lower on TiQR surfaces compared to Ti. In conclusion, our results suggest that NN structuration could improve biocompatibility of bare metal stents on endothelial cells and reduce platelet adhesion. Moreover, QR coating could reduce bacterial adhesion.