Evaluation of the flexural mechanical properties of various thermoplastic denture base polymers.

This study evaluated the flexural mechanical properties of various thermoplastic denture base polymers (six polyamides, four acrylic resins, polyester, polypropylene, and polycarbonate) by three different testing conditions; specimens were tested in water bath at 37°C (Wet/Water, by ISO 20795-1), or in ambient air (Wet/Air) after being immersed in distilled water for 50 h, or after desiccation for 7 days (Dry/Air). The mean ultimate flexural strength (UFS) and flexural modulus (FM) for most products ranged from 27 to 61 MPa and from 611 to 1,783 MPa respectively, which failed to meet the minimum requirements of the international standard, except for polycarbonate (89 and 2,245 MPa). The mean UFS and FM values were ranked Dry/Air>Wet/Air>Wet/Water (p<0.05). In conclusion, the flexural mechanical properties of denture base polymers varied with the products and were significantly affected by the testing medium (air or water) and specimen conditions (wet or dry).

Study protocol for a randomised controlled trial: harmonising optimal strategy for treatment of coronary artery stenosis - coronary intervention with next-generation drug-eluting stent platforms and abbreviated dual antiplatelet therapy (HOST-IDEA) trial.

INTRODUCTION: We have recently seen the introduction of newer generation drug-eluting stents with ultrathin struts that use advanced polymer technologies. However, the efficacy and safety of these newest stents have not yet been fully explored. In addition, there are still controversies over the optimal duration of dual antiplatelet therapy (DAPT) after stent implantation, particularly for ultrathin stents with the newest polymer technologies. METHODS AND ANALYSIS: The HOST-IDEA trial is a randomised, open-label, multicentre, non-inferiority trial and the first study to directly compare two of these ultrathin sirolimus-eluting stents: Orsiro stent with biodegradable polymer, and polymer-free Coroflex ISAR (CX-ISAR) stent. This study has a scheme of 2×2 factorial design according to the stent type and DAPT duration (3 vs 12 months). A total of 2152 patients will be randomised and stratified to demonstrate the non-inferiority of CX-ISAR to Orsiro, or of the abbreviated DAPT duration to the conventional 12 months (both in 1:1 ratio). For the comparison of stent type, the primary endpoint is target lesion failure (TLF), which is a composite of cardiac death, target vessel-related myocardial infarction and clinically driven target lesion revascularisation. For the comparison of DAPT duration, the net adverse clinical event is the coprimary endpoint, which is defined as a composite of TLF, definite/probable stent thrombosis and major bleeding. ETHIC APPROVAL AND DISSEMINATION: All the institutions involved in this study are required to have ethical approval prior to patient enrolment. This multicentre study will recruit patients through competitive registration, but institutions that have not yet obtained ethical approvals have made it impossible to enrol patients in a centralised web database. The final results will be presented at relevant international conferences and will be materialised in the form of papers. TRIAL REGISTRATION NUMBER: NCT02601157; Pre-results.

Impact of diabetes mellitus on angiographic and clinical outcomes in the drug-eluting stents era.

The effect of diabetes mellitus (DM) on angiographic restenosis and clinical outcomes after implantation of drug-eluting stents (DESs) has not been investigated in real-world practice. This study consisted of 226 patients who had DM and 560 patients who did not who underwent DES implantation between February 2003 and December 2003. We retrospectively compared the incidence of 6-month angiographic restenosis and 9-month major adverse cardiac events (MACEs), defined as cardiac death, myocardial infarction, and target lesion revascularization, between patients with and without DM. The 6-month angiographic restenotic rate (10.1% vs 8.2%, p = 0.41) and late loss (0.41 +/- 0.63 vs 0.36 +/- 0.65, p = 0.31) were similar between patients with and without DM. In addition, incidences of MACEs (4.9% vs 4.8%, p = 1.00) and target lesion revascularization (4.4% vs 4.1%, p = 0.84) were similar. Patients who had insulin-dependent DM manifested higher prevalences of restenosis (25.0% vs 8.5%, p = 0.04) and MACEs (17.2% vs 3.1%, p = 0.01) compared with patients who had non-insulin-dependent DM. In conclusion, in this study of real-world patients who underwent DES implantation, patients who had DM had restenotic rates and clinical outcomes that were similar to those in patients who did not have DM.

Epicardial delivery of VEGF and cardiac stem cells guided by 3-dimensional PLLA mat enhancing cardiac regeneration and angiogenesis in acute myocardial infarction.

Congestive heart failure is mostly resulted in a consequence of the limited myocardial regeneration capacity after acute myocardial infarction. Targeted delivery of proangiogenic factors and/or stem cells to the ischemic myocardium is a promising strategy for enhancing their local and sustained therapeutic effects. Herein, we designed an epicardial delivery system of vascular endothelial growth factor (VEGF) and cardiac stem cells (CSCs) using poly(l-lactic acid) (PLLA) mat applied to the acutely infarcted myocardium. The fibrous VEGF-loaded PLLA mat was fabricated by an electrospinning method using PLLA solution emulsified VEGF. This mat not only allowed for sustained release of VEGF for 4weeks but boosted migration and proliferation of both endothelial cells and CSCs in vitro. Furthermore, sustained release of VEGF showed a positive effect on in vitro capillary-like network formation of endothelial cells compared with bolus treatment of VEGF. PLLA mat provided a permissive 3-dimensional (3D) substratum that led to spontaneous cardiomyogenic differentiation of CSCs in vitro. Notably, sustained stimulation by VEGF-loaded PLLA mat resulted in a substantial increase in the expression of proangiogenic mRNAs of CSCs in vitro. The epicardially implanted VEGF-loaded PLLA mat showed modest effects on angiogenesis and cardiomyogenesis in the acutely infarcted hearts. However, co-implantation of VEGF and CSCs using the PLLA mat showed meaningful therapeutic effects on angiogenesis and cardiomyogenesis compared with controls, leading to reduced cardiac remodeling and enhanced global cardiac function. Collectively, the PLLA mat allowed a smart cargo that enabled the sustained release of VEGF and the delivery of CSCs, thereby synergistically inducing angiogenesis and cardiomyogenesis in acute myocardial infarction.

Clinical outcomes between different stent designs with the same polymer and drug: comparison between the Taxus Express and Taxus Liberte stents.

BACKGROUND/AIMS: The Taxus Liberte stent (Boston Scientific Co.) evolved from the Taxus Express stent, with enhanced stent deliverability and uniform drug delivery. This study was designed to compare angiographic and clinical outcomes in real-world practice between the Taxus Liberte and Taxus Express stents. METHODS: Between 2006 and 2008, 240 patients receiving the Taxus Liberte stent at three centers were registered and compared to historical control patients who had received the Taxus Express stent (n = 272). After propensity score matching, 173 patients treated with the Taxus Liberte stent and the same number of patients treated with the Taxus Express stent were selected. The primary outcome was a composite of major adverse cardiac events (MACE), including cardiac death, myocardial infarction (MI), ischemia driven target vessel revascularization (TVR), and stent thrombosis (ST) at 1 year. An additional angiographic assessment was conducted at 9 to 12 months. RESULTS: The study showed no significant difference between the Taxus Express and Taxus Liberte stents (death, 1.73% vs. 2.31%, p = 1.000; MI, 0% vs. 1.73%, p = 0.2478; TVR, 2.31% vs. 1.16%, p = 0.6848; and ST, 0% vs. 1.16%, p = 0.4986). The total MACE rate at 1 year did not differ between the groups (4.05% in Taxus Express vs. 4.05% in Taxus Liberte, p = 1.000). In addition, the binary restenosis rate did not differ (2.25% in Taxus Express vs. 1.80% in Taxus Liberte, p = 0.6848). CONCLUSIONS: In real-world experience with the two Taxus stent designs, both stents showed similarly good clinical and angiographic outcomes at 1 year. A long-term follow-up study is warranted.