nondestructive-monitoring-degradable-scaffold-based-tissue-engineered

Nondestructive Monitoring of Degradable Scaffold-Based Tissue-Engineered Blood Vessel Development Using Optical Coherence Tomography

Engineered vascular grafts with structural and mechanical properties similar to natural blood vessels are expected to meet the growing demand for arterial ...

Guangdong Academy of Medical Sciences, Guangdong General Hospital

Contrast-induced nephropathy (CIN) is an iatrogenic acute renal failure occurring following the intravascular injection of iodinated radiographic contrast medium. However, the regulatory mechanisms for CIN remain to be fully elucidated. The present study aimed to investigate whether atorvastatin protects against CIN via anti‑apoptotic effects by the upregulation of Hsp27 in vivo and in vitro. To determine whether atorvastatin attenuated CIN, the inflammatory response and apoptosis in vivo and in vitro, a rat model of iopamidol‑induced CIN was used, and human embryonic proximal tubule (HK2) cell damage was assessed. The rats were assigned into four groups (n=10 per group), as follows: Control rats; rats+atorvastatin; rats + iopamidol; rats+iopamidol+atorvastatin. In vitro, the HK2 cells were treated with iopamidol in the presence or absence of atorvastatin, heat shock protein (Hsp)27 small interfering (si)RNA or pcDNA3.1‑Hsp27. The renal tissues were examined histopathologically and collected for western blot analysis. The results showed that atorvastatin ameliorated the apoptosis and deterioration of renal function (P<0.05). Furthermore, atorvastatin reduced the iopamidol‑induced activity of B cell lymphoma‑2 (Bcl‑2)‑associated X protein (Bax)/caspase‑3 and increased the expression of Bcl‑2 in vivo and in vitro. Notably, following treatment with Hsp27 siRNA or pcDNA3.1‑Hsp27, it was found that iopamidol enhanced or weakened the upregulation of Bax/caspase‑3 and downregulation of Bcl‑2 in the HK2 cells, respectively. The results of the present study suggested that atorvastatin protected against contrast‑induced renal tubular cell apoptosis through the upregulation of Hsp27 in vivo and in vitro.

Atorvastatin protects against contrast-induced nephropathy via anti-apoptosis by the upregulation of Hsp27 in vivo and in vitro.

Fractional flow reserve (FFR) is the current gold standard to assess the physiological significance of coronary stenoses. With the development of coronary imaging techniques, several anatomic parameters have been investigated in vivo and their associations with FFR have been studied. The aim of this review is to summarize the accuracy of anatomic parameters derived by the present coronary imaging techniques including invasive coronary angiography, coronary computed tomography angiography, intravascular ultrasound and optical coherence tomography, in predicting a significant FFR. The impact of patient characteristics, lesion locations, variability of FFR and imaging resolution on the predictive ability are discussed.

A systematic review of imaging anatomy in predicting functional significance of coronary stenoses determined by fractional flow reserve.

Data are limited regarding outcomes of deferred lesions in patients with angiographically insignificant stenosis but low fractional flow reserve (FFR). We investigated the natural history of angiographically insignificant stenosis with low FFR among patients who underwent routine 3-vessel FFR measurement.

Clinical Outcomes of Deferred Lesions With Angiographically Insignificant Stenosis But Low Fractional Flow Reserve.

Non-destructive imaging strategies to monitor long-term cultures is essential for vascular engineering. The goal of this study is to investigate whether optical coherence tomography (OCT) can be a suitable approach to monitor the long-term remodeling process of biodegradable polymeric scaffold-based tissue-engineered vascular grafts (TEVG) after pulsatile stimulation and to observe polymeric scaffold degradation during bioreactor cultivation. In the present study, a perfusion system driven by a ventricular assist device was provided for a three-dimensional culture system as a pulsatile force. We characterized the structural features of wall thickness and polyglycolic acid degradation based on optical signal attenuation using catheter-based OCT. Scanning electron microscopy confirmed morphological changes. Also, polymer degradation and the detection of different types of collagen was visualized after 4 weeks of culture by means of polarized microscopy. Findings on OCT imaging correlated with those on histological examination and revealed the effects of pulsatile stimulation on the development of engineered vessels. This finding demonstrated that real-time imaging with OCT may be a promising tool for monitoring the growth and remodeling characterization of TEVG and provide a basis to promote the ideal and long-term culture of vascular tissue engineering.

In vitro remodeling and structural characterization of degradable polymer scaffold-based tissue-engineered vascular grafts using optical coherence tomography.

There are limited data on the clinical implications of total physiologic atherosclerotic burden assessed by invasive physiologic studies in patients with coronary artery disease. We investigated the prognostic implications of total physiologic atherosclerotic burden assessed by total sum of fractional flow reserve (FFR) in three vessels (3V-FFR).

Clinical implications of three-vessel fractional flow reserve measurement in patients with coronary artery disease.

Quantitative flow ratio (QFR) is a novel angiography-based method for deriving fractional flow reserve (FFR) without pressure wire or induction of hyperemia. The accuracy of QFR when assessed online in the catheterization laboratory has not been adequately examined to date.

Diagnostic Accuracy of Angiography-Based Quantitative Flow Ratio Measurements for Online Assessment of Coronary Stenosis.

The aim of this study was to investigate the prognostic implication of functional incomplete revascularization (IR) and residual functional SYNTAX (Synergy Between Percutaneous Coronary Intervention With Taxus and Cardiac Surgery) score (rFSS) in comparison with 3-vessel fractional flow reserve (FFR) and residual SYNTAX score.

Prognostic Implication of Functional Incomplete Revascularization and Residual Functional SYNTAX Score in Patients With Coronary Artery Disease.

Understanding of the risk conferred by functionally insignificant lesions in multiple coronary vessels is limited. We investigated the prognostic implications of coronary artery disease (CAD) based on 3-vessel fractional flow reserve (FFR).

Junqing Yang

Department of Cardiology

Guangdong Academy of Medical Sciences, Guangdong General Hospital

Nondestructive Monitoring of Degradable Scaffold-Based Tissue-Engineered Blood Vessel Development Using Optical Coherence Tomography

Junqing Yang

.css-o250i3{font-size:18px;font-family:Open Sans,sans-serif;line-height:21.6px;}Department of Cardiology

Guangdong Academy of Medical Sciences, Guangdong General Hospital

Nondestructive Monitoring of Degradable Scaffold-Based Tissue-Engineered Blood Vessel Development Using Optical Coherence Tomography

Department of Cardiology