[Show abstract][Hide abstract]ABSTRACT: Although heart valve replacement with either a mechanical or biological prosthesis is an effective method to treat valvular heart disease, both approaches have limitations, including thrombus formation, thromboembolism and degeneration problems. The study aim was to demonstrate the in-vitro endothelialization of hydroxyapatite (HAp) to be used as a biomaterial in heart valve prostheses.
The HAp samples were characterized using X-ray diffractometry to identify the crystalline phase, while the surface morphology of HAp discs was examined using scanning electron microscopy (SEM). Human umbilical vein endothelial cells (HUVECs) were cultured on HAp discs for 1, 3, 5, and 7 days, and on pyrolytic carbon discs for 7 days; cytotoxicity was assessed using the methyl thiazolyl tetrazolium (MTT) assay. The cells were incubated in three groups: (i) an experimental group (cultured with HAp extract); (ii) a negative control (cultured with high-density polyethylene chaff); and (iii) a positive control (culture medium containing 0.1% phenol solution).
A morphological examination of the HAp discs revealed the presence of micropores on the disc surface, together with cultured HUVECs. After seven days of culture, the HUVECs began to form a confluent endothelial cell layer covering the HAp discs. There were no visible cells attached to the pyrolytic carbon surface. The MTT assay indicated that HAp did not exert any cytotoxic effect on HUVECs, and low optical density values were obtained in the positive controls.
The study results showed that HUVECs were able to grow well on HAp discs, and that HAP possessed a good in-vitro bioactivity and biocompatibility towards these cells. Consequently, HAp might be used as a film on mechanical heart valve prostheses, and serve as a promising biomaterial for heart valve replacement.
No preview · Article · Jul 2010 · The Journal of heart valve disease
[Show abstract][Hide abstract]ABSTRACT: Valvular heart disease is a significant cause of morbidity and mortality worldwide. Artificial heart valves are currently the most widely accepted biomedical material. However, the material's blood compatibility is still not sufficient. Biomaterial with a good biocompatibility has not yet appeared. Our initial study was to evaluate the probable cytotoxicity of hydroxyapatite (HA) on human umbilical vein endothelial cells (HUVEC) for mechanical heart valve prosthesis applications.
Cell growth was tested by MTT assay and the cell relative growth rate (RGR) was calculated. Cells were cultured in media consisting of either leaching extracts of hydroxyapatite at 37 degrees C or leaching extracts at 121 degrees C or a negative and a positive control group, respectively. The cytotoxicity was graded using generally accepted standards. The RGR of cell lines cultured in the culture media consisting of either normal or heat temperature leaching extracts of hydroxyapatite and the negative controls were higher than in the positive controls. For 24 h, 48 h, and 72 h cultures, the cytotoxicity grade of HA was 0 in the normal temperature leaching extracts of hydroxyapatite and 1 in the heat temperature leaching extracts of hydroxyapatite.
Human umbilical cord endothelial cells grew well in the HA extracts. Our results indicate that HA possesses good IN VITRO bioactivity and biocompatibility with human umbilical cord endothelial cells and could be used as film on mechanical heart valve prostheses.
No preview · Article · Apr 2009 · The Thoracic and Cardiovascular Surgeon
[Show abstract][Hide abstract]ABSTRACT: We have found no study conducted economic issues on patient outcomes after heart transplantation (HTx) in China for further development.
From May 2004 to February 2006, there were 10 transplants performed in 9 male patients in our center: 1 heart lung recipient and 8 heart recipient. Among them, 7 lacked health insurance and 2 had insurance.
Their ages were between 24 years and 43 years (mean 39 years). The number of hospitalizations, number of days in hospital per admission, number of emergency room visits and mean left ventricular ejection fraction (LVEF) in the year before operation were 5.5, 54, 8.1 and 0.19 respectively. After operation, these figures decreased significantly to 1.7 (P<0.05), 18 (P<0.05), 1.1 (P<0.05) and 0.70 (P<0.05) respectively. During the follow up of 370~930d, one of the 9 patients who lacked health insurance died of acute rejection due to stopping mycophenolate mofetil (MMF) 7 months after operation and the heart lung recipient who also lacked health insurance died of pulmonary infection 1 year later. All patients who lacked health insurance experience emotional distress.
HTx is a good treatment for selected patients with end-stage heart failure (ESHF) and future research is to be expected in the fields of insurance coverage to improve the quality of life and the Chinese transplant group should be commended for their courageous work in the treatment of end stage heart disease under challenging circumstances.
No preview · Article · Jul 2008 · Annals of transplantation: quarterly of the Polish Transplantation Society