The engineered heart tissues (EHTs) present a promising alternative to current materials for native myocardial tissue due to the unique characteristics. However, until now, the clinical application of EHTs is limited by a serial of practical problems yet. Generally, the challenges need to further optimize include biomaterials, cell sources, and strategies of revascularization or establishment of EHTs. This review focuses on the newly progress on these aspects to encourage the emergence of novel EHTs that can meet clinic requirement properly.
Objective To observe the impact of collagen patches using 1-ethyl-3- （3-dimethylaminopropyl) carbod-iimide hydrochloride chemistry （EDC） to conjugate vascular endothelial growth factor （VEGF） ＋ basic fibroblast growth factor （bFGF） or VEGF alone on the survival rate of transplanted human bone morrow mesenchymal stem cells （hBM-MSCs）in vitro and in vivo. Methods Collagen patches which were activated by EDC were used as the control group，and EDC activated collagen patches that were conjugated with VEGF or VEGF ＋ bFGF were used as the experiment groups（VEGF group and VEGF ＋ bFGF group）. hBM-MSCs （0.5×106/patch） were used as seeding cells to construct engineered heart tissue （EHT）. MTT assay was performed to assess in vitro proliferation of hBM-MSCs on 3 different collagen patches. Ventricular aneurysm model after myocardial infarction was created by left anterior descending artery （LAD） ligation in male SD rats，and EHT which were constructed with 3 different patches were used for ventricular plasty. Four weeks later，immunofluorescence staining was used to examine arteriole density （anti-α-SMA staining） and transplanted cell survival （anti-h-mitochondria staining）. Results （1） hMSCs proliferation in VEGF group and VEGF ＋ bFGF group was significantly better than that in the control group on the 2nd and 4th day after cell transplantation （P＜0.05）； （2） Four weeks afterEHT implantation，immunofluorescence staining for α-SMA revealed that arteriole density of VEGF group and VEGF ＋ bFGF group was significantly higher than that of the control group （P＜0.05）； （3） Immunofluorescence staining forh-mitochondria showed that survival rates of transplanted hBM-MSCs of VEGF group and VEGF ＋ bFGF group were significantly higher than that of the control group （P＜0.05）； （4） There was a significantly positive correlation between survival rate of hBM-MSCs and arteriole density （r 2=0.99，P=0.02）. Conclusion VEGF or VEGF ＋ bFGF conjugated collagen patch can significantly improve hBM-MSCs proliferation in vitro and enhance survival rate of transplanted hBM-MSCs by accelerating revascularization of EHT in vivo.
ObjectiveTo summarize the surgical strategy on treating mitral desease patient associated with hypertrophic obstructive cadiomyopathy (HOCM). MethodsWe retrospectively analyzed the clinical data of 17 patients with HOCM underwent surgical treatment from November 2003 to May 2015 year. There were 10 males and 7 females with a mean age of 42.2±15.5 years ranging from 7-62 years. There were 16 patients underwent modified Morrow procedure and 1 patient underwent modified Konno procedure to relieve the obstruction of left ventricular outflow tract. And different surgical treatment of mitral valve disease was implemented depending on the severity of regurgitation and under monitoring of transesophageal echocardiography. About 2 weeks after the surgery, we performed transthoracic echocardiography to evaluate the effect of operation. ResultsNo hospital death occurred and the surgery obviously improved the symptom and cardiac function in all cases. After surgery, echocardiography revealed that the mean thickness of the ventricular septum statistically decreased (P < 0.0001), the systolic anterior motion disappeared, the outflow track pressure of left ventricle statistically decreased (P < 0.0001), and the peak flow rate of left ventricle statistically decreased. However, there was no statistical difference in the change of the left ventricular ejection fraction(P=0.083). Nine patients with no mitral regurgitation (MR) or mild MR only underwent the unblock of the left ventricular outflow track, the MR decreased to mild or disappeared. Four patients with moderate or severe MR underwent mitral valve repair, and the MR decrease to mild or disappear. There were no complications occurred regarding to prosthesis implantation over the 4 patients underwent mitral valve replacement for infective endocarditis or other causes. ConclusionFor the HOCM patients with mild MR, the unblock of the left ventricular outflow track alone can effectively improve the MR. For those combined with moderate or severe MR, we should choose mitral valve repair or replacement based on individual situation of patient.
ObjectiveTo investigate the feasibility of animal model of the reconstruction of right ventricular outflow tract in rats.MethodsA total of 15 female Sprague-Dawley (SD) rats underwent right ventricular outflow tract reconstruction surgery. Before the operation, the collagen scaffolds were treated with g 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride chemistry (EDC), and seeded with human bone marrow stem cells (h-MSCs). Three days after the surgery, 3 rats were randomly sacrificed to evaluate the transmural resection of right ventricular outflow tract. One or 3 months later, other 3 rats at each timepoint were sacrificed, stained with Masson’s Trichrome to observe the degradation of scaffold. Furthermore, 4 weeks after the surgery, 4 rats were sacrificed and the hearts were sliced. Anti-human mitochondria staining was used to identify the survival of seeding cells.ResultsThe transmural resection of right ventricular outflow tract was feasible in rats at an acceptable mortality (13.3%). After EDC treatment, the degradation rate of collagen scaffold was extended greatly. The seeding cells were detected by anti-mitochandria immunofluorescent staining in all patches 4 weeks after the operation.ConclusionRat model of right ventricular outflow tract reconstruction could be a stable, reliable and economical screening model for engineered heart tissue research.