Delayed re-endothelialization is one of the major disadvantages in synthetic vascular grafts, especially in small-diameter grafts (inner diameter <6 mm), leading to thrombosis and stenosis of the grafts. Simvastatin, a serum cholesterol-lowering drug, has promotional effects on endothelial progenitor cell (EPC) mobilization from bone marrow and recruitment to sites of vascular injury exhibiting acceleration of re-endothelialization. In this study, we prepared double-layer vascular patches from Thai silk fibroin/gelatin with gelatin hydrogel incorporating simvastatin-micelles (SM) for sustained release of simvastatin to recruit circulation EPCs. To enhance simvastatin solubility, simvastatin was entrapped in micelles of l-lactic acid oligomer-grafted gelatin. The drug loading efficiency was at 4.1 ± 0.5 μg/mg micelles. SM had a chemoattractive effect on EPCs comparable to nonmodified simvastatin. Gelatin hydrogel incorporating SM at 100 μM of simvastatin (GSM100) could enhance in vitro EPC activities of adhesion and proliferation. In vitro results showed the initial cell adhesion of 86%, specific growth rate of 15.33×10(-3) h(-1), and population doubling time of 46.21 h. In vivo implantation of the patches incorporating SM significantly increased the recruitment of circulating EPCs. From the results of immunofluorescence staining, they demonstrated the complete re-endothelialization on the implanted patches containing SM at 2 weeks after implantation in rat carotid arteries. The gelatin hydrogel incorporating SM could be an effective inner layer of multifunctional vascular grafts to accelerate re-endothelialization in vascular tissue engineering.

Prehypertension and serum uric acid are emerging as independent risk factors for arterial stiffness and may also predict cardiovascular diseases. Previous studies have demonstrated the association between serum uric acid and arterial stiffness in hypertensive adults, but there are limited studies in prehypertensive adults. We compared the serum uric acid (SUA) and cardio-ankle vascular index (CAVI) between normotensive and prehypertensive participants. The association between SUA, prehypertension and CAVI were investigated. One hundred and eighteen participants were recruited and divided into two groups according to their blood pressure (normotensive, 53 and prehypertensive, 65). Blood pressure, resting heart rate, pulsatile stress, height, waist circumference and body composition were measured. After an overnight fast, blood samples were collected to measure lipid profile and SUA levels. Arterial stiffness was assessed according to the CAVI. The results showed that the SUA and CAVI of the prehypertensive group were significantly higher than those of the normotensive group. Multiple regression analysis demonstrated that CAVI was significantly correlated with age, systolic blood pressure and SUA. Furthermore, prehypertension and high SUA were significantly associated with increased risk of abnormal CAVI (relative risk, 2.696; 95% CI, 1.552-4.683; p < .001). The study demonstrated that prehypertension and high SUA significantly increased the risk of arterial stiffness as assessed by CAVI.

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Sericin, one of the two main proteins of silk cocoon besides fibroin, has been wildly used as ingredient in cosmetic products and nutrition supplements; however there are considerable controversial reports on its toxicity to cells and its advantages. This work aimed to investigate cell biocompatibility of sericin both in the systems of blended silk fibroin/sericin and pure sericin films using L929 mouse fibroblasts. The effect of concentration of commercial heat extracted sericin on cell viability was first investigated in the system of silk fibroin/sericin (F/S) films using 2 types of silk fibroin, Bombyx mori Nangnoi Srisaket 1 and Bombyx mori Jul 1/1. For both types of silk fibroin, it was found the lower cell number attached and proliferated on the blended F/S films at all sericin concentrations, compared to that on glass and pure fibroin. However, proliferation rate of cells cultured on the blended F/S films was similar to that of cells cultured on glass and pure fibroin films, as confirmed by population doubling time (PDT). Cytotoxicity of sericin extracted from 4 different methods including heat, acid, alkali and urea treatments was further studied in this work in the system of pure sericin films. It could be seen that acid and urea extracted sericin films showed high percentage of cell attachment at 92% and 88%, respectively. However, number of cells proliferated on all sericin films after 48 h culture was not significantly different. This indicated that L929 cells had different proliferation rate when cultured on different types of sericin films. Among 4 extraction methods, the PDT of cells proliferated on urea extracted sericin film was lowest (27 h) and also lower than that of the blended F/S films. This study suggested that sericin extracted by urea treatment could enhance proliferation rate of L929 mouse fibroblasts.

Objective: Smoking is a leading risk factor for various diseases including peripheral arterial disease (PAD). PADis a form of cardiovascular disease that affects the blood vessels, resulting in vascular stiffness and occlusion. The ankle-brachial index (ABI) and cardio-ankle vascular index (CAVI) are non-invasive techniques for detection of vascularocclusion and stiffness, respectively. To determine the association between cigarette smoking and peripheral arterialconditions, the ABI and CAVI of smokers and non-smokers were investigated.Material and Method: One hundred and forty one middle-aged participants without underlying diseases wereenrolled, 49 smokers and 92 non-smokers. A questionnaire was developed to collect the demographic information,medical history, and smoking behaviours of the participants, and their ABI and CAVI were measured.Results: Our results showed that the CAVI values of smokers (7.88±1.26) were significantly differed from those ofnon-smokers (7.17±0.94) at p-value <0.001. In addition, age and cigarette smoking were independent factors significantlyrelated to the CAVI values by a multivariate analysis. Likewise, we found a positive relationship between the CAVIvalues and the number of cigarettes smoked per day (r=0.31) and the length of smoking duration (r=0.42) at p-value<0.001. However, the ABI values between smokers and non-smokers were not different.Conclusion: This study demonstrated that age and smoking were significantly related to CAVI, and a greater number ofcigarettes smoked per day and longer smoking duration had positive relationships to CAVI values.