Search

Background Short-term dual antiplatelet therapy (DAPT) is a suitable strategy after stent implantation especially in patients at high risk for bleeding. The thromboresistant characteristics and the healing profile permanent polymer stents such as the Resolute Onyx- drug-eluting stent (DES) has never been tested against the current approved stents for short-term DAPT, the polymer free (PF) biolimus-eluting stent (PF-BES) and bare metal stents (BMS) in dedicated preclinical models. Methods An ex-vivo porcine arteriovenous shunt and in-vivo flow loop model were used to evaluate thromboresistance. The healing profile was assessed in the rabbit model at 28 days by confocal microscopy (CM), scanning electron microscopy (SEM) and histology. Onyx-DES was separately compared with Onyx-BMS in first experiment and PF-BES in second experiment. Results In an ex-vivo shunt model, CM and SEM showed significantly less platelet adhesion for Onyx-DES relative to Onyx-BMS and PF-BES. In a flow loop model using human blood, platelet adhesion was also significantly less in Onyx-DES as compared to PF-BES and Onyx-BMS. In the healing study, Onyx-BMS showed significantly greater healing profile relative to Onyx-DES as expected, whereas Onyx-DES showed equivalent endothelial coverage by SEM and significantly less Evan's blue uptake and comparable colocalization of p120 and vascular endothelial-cadherin when compared with PF-BES. Conclusions Onyx-DES showed qualities of thomboresistance and healing which appear to be compatible with short-term DAPT. Thromboresistance was superior to PF-BES and healing was equivalent to PF-BES in this pre-clinical study. Onyx-DES might provide advantages when considering short-term DAPT especially in patients at high risk of bleeding.

Background Polymer-coating represents one of components of drug-eluting stents (DES) to have experienced a more intensive technological evolution. Polymer-free DES (PF-DES) have offered promising angiographic results, with earlier complete re-endothelization, potentially reducing the thrombotic risk and offering the option of a shorter antiplatelet therapy. However, contrasting prognostic data have been reported so far with PF-DES. Therefore, the aim of the present study was to perform a comprehensive updated meta-analysis of randomized trials (RCT) comparing the impact of PF-DES vs polymer- coated DES (PC-DES) on clinical outcome. Methods Literature and main scientific session abstracts were searched for RCTs comparing PF-DES vs PC-DES for the treatment of CAD. The primary efficacy endpoint was mortality, secondary endpoints were cardiovascular death, myocardial infarction, target lesion revascularization (TLR) and stent thrombosis. Results We included 16 randomized clinical trials, with a total of 15,689 patients, including 50.6% randomized to PF-DES. At a median follow-up of 24 months, PF-DES were associated to a significant reduction in mortality as compared to PC-DES (0.82 [0.68, 0.99], p = .03, I2 = 0%; phet = 0.93). However, no significant benefit was observed in terms of cardiovascular death or major ischemic endpoints (respectively CV death: OR [95% CI] = 0.92 [0.71, 1.18] p = .50, I2 = 0.50; phet = 0.84; MI: OR [95% CI] = 1.08 [0.90, 1.29], p = .42; I2 = 0%, phet = 0.98; TLR: OR [95% CI] = 1.02 [0.78, 1.32], p = .91; I2 = 0.63 phet = 0.0003; ST: OR [95% CI] = 0.98 [0.87, 1.10], p = .72; I2 = 0% phet = 0.64). By meta-regression analysis, the mortality benefits of PF-DES were not conditioned by the rate of diabetes mellitus or acute coronary syndromes. Conclusions Based on the current meta-analysis, PF-DES are associated to a significant reduction in mortality as compared to PC-DES, but not in the occurrence of major ischemic events. Future larger studies are certainly needed to further investigate and confirm our findings, especially in particular subsets of patients, such as those with high bleeding risk or acute myocardial infarction.

An efficient and reliable transfer for graphene onto the substrates of interests acts as the crucial bridge between the graphene synthesis and applications. The main reason that this issue has not been fully addressed is the use of a polymer medium to protect the one-atom-thick material during the transfer process. Here we demonstrate a general and scalable method to transfer chemical-vapor-deposited graphene onto arbitrary surfaces without any polymers, which yields the transfer of macroscopically and microscopically clean, continuous and uniform graphene samples onto a wide variety of substrates, as well as the scalable layer-by-layer graphene epitaxial structures. Moreover, the transferred graphene exhibits an overall 100% enhancement in the electrical conductivity compared with the conventional method, so that various high-performance flexible transparent electrodes can be demonstrated. We believe that this new transfer technique will offer the opportunities to the industrialization of next generations of flexible electronics and other graphene-based disruptive technologies.

The fluoropolymer paclitaxel-eluting stent (FP-PES; Eluvia, Boston Scientific, Marlborough, Massachusetts) is the new-generation drug-eluting stent, allowing controlled and sustained paclitaxel release over 12 months after stent implantation. To date, however, there are few data regarding vascular

Despite impressive improvements in drug-eluting stent (DES) technologies, patients with diabetes remain at high risk for adverse events after percutaneous revascularization. Among novel DES, the Cre8 polymer-free amphilimus-eluting stent (AES) has shown promising results [(1)][1]. Recently, we

The paper reports the synthesis and characterization of curcumin (CUR) and beta-cyclodextrin (β-CD) based inclusion complexes (ICs) prepared using co-solvent (IC-1) and common solvent (IC-2) precipitation techniques. The complexes were subjected to thermal and microstructural characterization to study the complexation behavior of the ICs. IC-2 exhibited a complete encapsulation of CUR with β-CD from both sides. The morphological and in-vitro release of CUR in Phosphate Buffer Saline (PBS) was evaluated. The fabrication of nanoparticles (NPs) of IC-2 led to the finest particle diameter (~ 350 nm) and minimal diameter variation using the Taguchi design of experiments. The study demonstrates the possibility to fabricate optimally controlled NPs of CUR/ β-CD IC, exhibiting the significant potential to be electrosprayed on biomedical surfaces of implants and devices with enhanced efficacy and stability of CUR release.

In this study, sirolimus (SRL) was loaded within biomimetic apatite formed on cobalt-chromium (Co-Cr) alloy, which has been reported for the first time, to inhibit the in-stent restenosis. Two different groups of loading SRL within biomimetic apatite were prepared: Group A (mono-layer of apatite/SRL) and Group B (bi-layer of apatite/SRL). Group A and Group B showed the biphasic pattern of SRL release up to 40 and 90days, respectively. The attachment of human artery smooth muscle cell (HASMC) for both Group A and Group B was significantly inhibited, and proliferation dramatically decreased with the release of SRL. Noteworthily, biomimetic apatite alone also suppressed the SMC proliferation. The porous biomimetic apatite uniformly covered Co-Cr stent without crack or webbings. After balloon expansion, the integrity of biomimetic apatite was sufficient to resist delamination or destruction. Thus, this study demonstrated that biomimetic apatite is a promising drug carrier for potential use in stents.

Background To assess clinical outcomes of patients needing short dual antiplatelet therapy (S-DAPT) after PCI with Cre8 polymer-free amphilimus eluting-stent (AES). The Cre8-AES with pure i-Carbofilm coating was supposed to induce faster stent endothelialization and reduce device thrombogenicity. Methods We performed a sub-analysis of unrestricted consecutive patients treated with Cre8-AES between August 2011 and January 2015. Two groups were formed: 1) patients discharged with S-DAPT (≤ 3-month), because of high bleeding risk or attending urgent non-cardiac surgery; and 2) patients discharged with Recommended DAPT duration (R-DAPT; ≥ 6-month). The primary ischemic- and bleeding-safety endpoints were Target Vessel Failure (TVF, composite endpoint of cardiac-death, target vessel-myocardial infarction and target vessel-revascularization), and major-bleeding (BARC ≥ type-3a) at 6-month and 1-year. Results 106 patients (8.7%) were discharged with ≤ 3-month DAPT (83 ± 19 days; S-DAPT group) and 1102 patients (90.6%) with ≥ 6-month DAPT (342 ± 62 days; R-DAPT group). Between S-DAPT and R-DAPT groups no significant differences were observed in TVF at 1-year (5.7% vs 5.1%); 1-year BARC major bleeding rate was higher in S-DAPT group (3.4% vs 0.2%, p = 0.007) with all bleeding events occurred within 3 months. The landmark analysis (started at 90 days, ended at 1 year) showed no differences in BARC major bleedings between groups (0% vs. 0.3%). Conclusions The results of this multicenter registry show that the use of Cre8 AES in patients needing short DAPT (≤ 3-month) was safe regarding ischemic events and could favor a reduction of bleeding events related to the recommended DAPT. A large randomized trial is necessary to support these preliminary findings.

Objectives This study sought to assess the safety and effectiveness of the drug-filled stent (DFS) (Medtronic, Santa Rosa, California) in the treatment of patients with coronary artery disease. Background Polymer-free drug-eluting stents have the potential to improve clinical outcomes and facilitate shorter durations of dual antiplatelet therapy. The polymer-free DFS is made from a trilayered continuous wire with an outer cobalt chromium layer, a middle tantalum layer, and an inner lumen coated with sirolimus. Small laser-drilled holes on the abluminal stent surface control drug elution. Methods The RevElution trial enrolled 100 patients with de novo coronary lesions 2.25 to 3.50 mm in diameter and length ≤27 mm in 2 cohorts of 50 patients for angiographic, intravascular ultrasound, and clinical assessment at 9 or 24 months, with optical coherence tomography performed in a subset of 30 patients at each time period. The primary endpoint was angiographic in-stent late lumen loss at 9 months compared with Resolute zotarolimus-eluting stent (Medtronic) historical control data. Results Fifty patients with 56 lesions were treated with DFS in the 9-month cohort. In-stent late lumen loss was 0.26 ± 0.28 mm for DFS and 0.36 ± 0.52 mm for Resolute (pnoninferiority Conclusions At 9 months, the polymer-free DFS was safe and effective with high rates of early strut coverage and noninferior late lumen loss compared to Resolute. (Medtronic RevElution Trial [RevElution]; NCT02480348)

Vessel healing seems to be associated with stent strut coverage at an early post-implantation stage and is potentially related to stent thrombosis ([1][1]). We report the results of a randomized controlled trial to assess the timing and degree of intracoronary healing of 2 different sirolimus

A polymer-based coronary drug-eluting stent might induce inflammation and stent thrombosis of the vessel wall due to the presence of the polymer. Therefore, the purpose of this study was to compare synthetic poly lactic–glycolic acid (PLGA)-based tacrolimus (TCL)-eluting stents (PLGA-TES) and polymer-free TCL-eluting stents (PF-TES) in in vitro and in vivo models. The PF-TES was deposited with a TiO2 thin film onto a bare metal stent (BMS) using plasma-enhanced chemical vapor deposition (PECVD). The surface morphologies of the stents were investigated by scanning electron microscopy and energy dispersive X-ray spectroscopy methods. The effect of the drugs released from the stents on smooth muscle cell (SMC) proliferation and platelet adhesion were examined. Animal studies were performed with four study groups; 1) BMS, 2) N-TiO2, 3) PLGA-TES, and 4) PF-TES. Further, after 4 weeks of implantation, the vessels surrounding the stents were isolated and then subjected to various analyses. In this study, the stent was deposited with a very thin and uniform TiO2 film. The platelet adhesion on the TiO2 surfaces was less than that on the BMS surface. The drug was uniformly coated on the stent surface with a concentration of 1.184 μg/mm2. SMC proliferation was significantly inhibited in the TCL-eluting stent group (62.8 %, 42.3 %, n = 7, p

Drug release profile due to the presence of polymer as well as chronic outward force of the self-expanding stent may lead to critical difference in the vessel responses in peripheral artery disease. The aim of this study was to compare the healing responses in vessels treated with polymer free

No randomized studies have compared paclitaxel-eluting stents with self-expanding bare-metal stents as a primary objective for the treatment of femoropopliteal lesions. The primary objective of the BATTLE trial is to demonstrate the clinical superiority of Zilver PTX (Cook) versus Misago (Terumo) in

In the SORT OUT IX trial, the biolimus A9-coated BioFreedom stent, a stainless steel drug-coated stent devoid of polymer (BF-BES), did not show noninferiority to the biodegradable polymer ultrathin strut sirolimus-eluting Orsiro stent (O-SES). The aim of this substudy was to compare the clinical

A polymer-free biolimus A9 coated and eluting stent (PF-BCS) followed by 1-month dual antiplatelet therapy has been shown to be safer and more effective than a bare-metal stent in high bleeding risk patients undergoing PCI in a clinical trial setting. However, little is known about the performance

Although recent randomized control trial reported that the polymer-coated, paclitaxel-eluting stent (Eluvia) was non-inferior to the polymer-free, paclitaxel-coated stent (Zilver PTX) for femoropopliteal (FP) artery lesion, there are no intravascular ultrasound (IVUS) data about the difference of

Recently, polymer free fracturing fluid was investigated to reduce formation and fracture conductivity damage during and after hydraulic fracture treatment. This fluid system uses a viscoelastic surfactant (VES). Some shortcomings of VES fluid such as excessive leakoff and the limit of temperature range have limited the use of the conventional VES fluid. On the basis of the conventional VES fracturing fluid system, a new anionic VES fracturing fluid “D3F-AS05” was developed through an extensive experiments. The fluid utilizes a specially formulated anionic surfactant. Analysis of laboratory tests indicates that the new fluid has good viscosity stability with high ability of carrying sand; the fluid also has low fluid loss and low frictional resistance. On the other hand, more than 97% returned permeability was achieved, which indicates low formation damage after gel-breaking. The temperature stability of the new fluids extended to more than 90 °C. This allowed the fluid to be used in the deep well with a high injection rate. This paper provides the procedures and the chemical additive of the new fluid and has focused on the performance of the fluid under different concentrations. The paper also illustrates the effect of the fluid in fracture geometry with a field application result.

The increased risk of late ischemic events with drug eluting stents (DES) may, in part, be due to persistent inflammation and delayed vascular healing induced by their durable polymer (DP) coating. Biodegradable-polymer (BP-) and polymer-free (PF-) DES were developed in an attempt to mitigate this

Permanent-polymer everolimus-eluting stents (EES) have proven in several randomized trials and observational registries to provide satisfactory safety and effectiveness results in patients undergoing percutaneous coronary intervention. However, the permanence of synthetic polymer still poses a

Polymer-free drug-coated stents (PF DCS) avoid the concern for inflammatory material responses, but pose challenges in providing controlled drug release and sustained tissue retention. We used immunofluorescence (IF) methods to contrast the arterial distribution of Sirolimus and the highly

Despite all the benefits of drug-eluting stents (DES), concerns have been raised over their long-term safety, with particular reference to stent thrombosis. In an effort to address these concerns, newer stents have been developed that include: DES with biodegradable polymers, DES that are polymer free, stents with novel coatings, and completely biodegradable stents. Many of these stents are currently undergoing pre-clinical and clinical trials; however, early results seem promising. This paper reviews the current status of this new technology, together with other new coronary devices such as bifurcation stents and drug-eluting balloons, as efforts continue to design the ideal coronary stent.

The increased risk of late ischemic events with drug eluting stents (DES) may, in part, be due to persistent inflammation and delayed vascular healing induced by their durable polymer (DP) coating. Biodegradable-polymer (BP-) and polymer-free (PF-) DES were developed in an attempt to mitigate this

Polymer-free drug-eluting stents(PF-DES) were developed to mitigate the risk of late ischemic events observed with durable-polymer DES (DP-DES). However, trial results are inconsistent with longer-term safety and efficacy of PF-DES unknown. We performed a meta-analysis of randomized controlled

The purpose of this all-comers registry was to assess the safety and efficacy of a polymer-free sirolimus coated, ultrathin strut drug eluting stent (PF-SES) with a focus on acute coronary syndrome (ACS). Elective coronary artery disease (CAD) patients on short (≤ 6 months) and long (> 6 months)

We sought to evaluate the angiographic efficacy and clinical safety and effectiveness of the combined sirolimus-eluting CD34 antibody coated Combo stent (OrbusNeich Medical, Ft. Lauderdale, Florida) in a randomized trial designed to enable its approval by the China Food and Drug Administration.

Current literature has limited data on efficacy of polymer-free drug-coated stents (PFS) in treatment of coronary artery disease. The objective of our meta-analysis is to assess the efficacy of PFS compared to polymer-based drug-eluting stents (PBS) from currently published randomized controlled

Patients with diabetes mellitus (DM) remain at higher risk for stent restenosis and adverse cardiovascular events, even in the drug-eluting stent era. The polymer free (PF) Amphilimus-eluting stent (AES) has shown promising preliminary results in patients with DM. The aim of this study was to

US guidelines currently recommend 12 months of uninterrupted DAPT after implantation of DES. Prolonged and more powerful DAPT regimens have offered benefit by reducing VLST, but at the cost of increased risk of bleeding. There is an emerging need for new stents that are less dependent on prolonged

Non-exponential fluorescence decays due to the photochemical reaction of 10-cyano-9-tert-butyl-anthracene towards the Dewar isomer are analyzed to gain information on the free volume of a polymer glass (poly- n -butyl-methacrylate) at different temperatures. The simple model of a multiexponential fitting procedure is well suited to following the temperature dependence in the envelope of this distribution qualitatively, but it fails to detect finer structures. More demanding methods (maximum entropy and exponential series) result in at least trimodal distributions indicating preferred polymer free volume voids within a broad distribution. Increasing temperature favours the decay time range associated with the largest free volume void.