The dual-therapy COMBO stent: a rationale for a light dual antiplatelet therapy treatment

Biological response of degradation products of PEO-modified magnesium on vascular tissue cells, hemocompatibility and its influence on the inflammatory response

Cardiovascular stenting is the most widely used therapy to treat coronary artery disease caused by partial or total obstruction of the artery due to atherosclerotic plaque formation, with potentially fatal effects. There are different types of stents: bare metal stents, drug-eluting stents, bioabsorbable stents and dual therapy stents. However, they can lead to long-term complications, such as in-stent restenosis and late thrombosis. To reduce these adverse effects, research has focused on biodegradable metallic stents, since they retain the mechanical properties necessary to contain the injured artery while it is being repaired and, once their function has been fulfilled, the stent degrades without altering the system or compromising the patient's health. In this work we have evaluated the biological response of the degradation products of a bare Mg based biomaterial surface-modified by the plasma electrolytic oxidation (PEO) method on vascular tissue cells, hemocompatibility and inflammatory response. The results obtained are compatible with a biosafe material for future use as a cardiovascular implant, but it is necessary to continue with in vivo and mechanical properties tests to ensure and guarantee its use. SIGNIFICANCE STATEMENT: The development of fully bioresorbable stents is a promising alternative for the management of coronary artery disease without causing long-term problems at the implantation site. In this work, the hematological and immunological biocompatibility of bare Mg modified superficially by plasma electrolytic oxidation (PEO-Mg) was evaluated by in vitro and ex vivo assays. PEO-Mg was found to be compatible with blood and immune components surrounding the implantation site with no signs of toxicity to endothelial cells, macrophages, and arterial tissue. In addition, degradation products of PEO-Mg are eliminated by phagocytosis. However, an in-depth study of the physical and mechanical properties and in vivo biocompatibility must be carried out for its future use as a biomedical implant.

The Bioengineered Combo Dual-Therapy CD34 Antibody-Covered Sirolimus-Eluting Coronary Stent in Patients with Chronic Total Occlusion Evaluated by Clinical Outcome and Optical Coherence Tomography Imaging Analysis

We sought to determine the effects of the use of a Bioengineered Combo Dual-Therapy CD34 Antibody-Covered Sirolimus-Eluting Coronary Stent (Combo^® DTS) in patients with chronic total occlusion (CTO) by evaluating clinical outcomes and by performing an optical coherence tomography (OCT) analysis. We retrospectively analyzed data from 39 patients who had successfully undergone OCT-guided revascularization of a CTO being treated with a Combo^® DTS. Clinical assessment, angiography (with quantitative coronary angiography analysis) and OCT examination were performed at baseline and at follow-up. The median follow-up period was 189 days, ranging from 157 to 615 days. At follow-up, revascularization was required due to angiographic restenosis in 40% (14 of 35) of patients. OCT analysis detected neointima proliferation in 23 (76.6%) patients. Neointima formation was often associated with microvessels in 18 patients (60%). Neoatheroslcerosis was observed in 2 (6.6%) patients. Malapposition was found in 4 patients (13.3%), and stent fractures were found in 11 patients (36.6%). Rate of strut coverage was 96.3% at follow-up. In conclusion, the implantation of a Combo^® DTS after successful CTO recanalization was associated with a restenosis rate of 40% despite good stent implantation at baseline, proven by OCT. Neointima formation was found as a main contributor to restenosis. Nevertheless, we observed a low rate of major cardiovascular events in our follow-up.

Single and multi-functional coating strategies for enhancing the biocompatibility and tissue integration of blood-contacting medical implants

Device-associated clot formation and poor tissue integration are ongoing problems with permanent and temporary implantable medical devices. These complications lead to increased rates of mortality and morbidity and impose a burden on healthcare systems. In this review, we outline the current approaches for developing single and multi-functional surface coating techniques that aim to circumvent the limitations associated with existing blood-contacting medical devices. We focus on surface coatings that possess dual hemocompatibility and biofunctionality features and discuss their advantages and shortcomings to providing a biocompatible and biodynamic interface between the medical implant and blood. Lastly, we outline the newly developed surface modification techniques that use lubricant-infused coatings and discuss their unique potential and limitations in mitigating medical device-associated complications.