Department of Advanced Interdisciplinary Studies, Institute of Basic Medical Sciences, Tissue Engineering Research Center, Academy of Military Medical Sciences, 27 Taiping Road, Beijing 100850, PR China.
Cardiovascular Department, Chinese PLA General Hospital, 28 Fuxing Road, Beijing 100853, PR China; Shijingshan Teaching Hospital of Capital Medical University, Beijing Shijingshan Hospital, Beijing 100043, PR China.
Biomaterials. 2014 Apr;35(13):3986-98. doi: 10.1016/j.biomaterials.2014.01.021. Epub 2014 Feb 6.
The ability to restore heart function by replacement of diseased myocardium is one of the great challenges in biomaterials and regenerative medicine. Brown adipose derived stem cells (BADSCs) present a new source of cardiomyocytes to regenerate the myocardium after infarction. In this study, we explored an injectable tissue engineering strategy to repair damaged myocardium, in which chitosan hydrogels were investigated as a carrier for BADSCs. In vitro, the effect and mechanism of chitosan components on the cardiac differentiation of BADSCs were investigated. In vivo, BADSCs carrying double-fusion reporter gene (firefly luciferase and monomeric red fluorescent protein (fluc-mRFP)) were transplanted into infarcted rat hearts with or without chitosan hydrogel. Multi-techniques were used to assess the effects of treatments. We observed that chitosan components significantly enhanced cardiac differentiation of BADSCs, which was assessed by percentages of cTnT(+) cells and expression of cardiac-specific markers, including GATA-4, Nkx2.5, Myl7, Myh6, cTnI, and Cacna1a. Treatment with collagen synthesis inhibitors, cis-4-hydroxy-D-proline (CIS), significantly inhibited the chitosan-enhanced cardiac differentiation, indicating that the enhanced collagen synthesis by chitosan accounts for its promotive role in cardiac differentiation of BADSCs. Longitudinal in vivo bioluminescence imaging and histological staining revealed that chitosan enhanced the survival of engrafted BADSCs and significantly increased the differentiation rate of BADSCs into cardiomyocytes in vivo. Furthermore, BADSCs delivered by chitosan hydrogel prevented adverse matrix remodeling, increased angiogenesis, and preserved heart function. These results suggested that the injectable cardiac tissue engineering based on chitosan hydrogel and BADSCs is a useful strategy for myocardium regeneration.
通过替换病变心肌来恢复心脏功能是生物材料和再生医学的重大挑战之一。棕色脂肪来源的干细胞（BADSCs）为梗死心肌再生提供了一种新的心肌细胞来源。在这项研究中，我们探索了一种可注射的组织工程策略来修复受损的心肌，其中壳聚糖水凝胶被研究为 BADSCs 的载体。在体外，研究了壳聚糖成分对 BADSCs 心脏分化的作用和机制。在体内，将携带双融合报告基因（萤火虫荧光素酶和单体红色荧光蛋白（fluc-mRFP）的 BADSCs 移植到有或没有壳聚糖水凝胶的梗死大鼠心脏中。使用多种技术评估了治疗效果。我们观察到壳聚糖成分显著增强了 BADSCs 的心脏分化，这可以通过 cTnT(+)细胞的百分比和心脏特异性标志物的表达来评估，包括 GATA-4、Nkx2.5、Myl7、Myh6、cTnI 和 Cacna1a。用胶原合成抑制剂 cis-4-羟基-D-脯氨酸（CIS）处理，显著抑制了壳聚糖增强的心脏分化，表明壳聚糖增强的胶原合成是其促进 BADSCs 心脏分化的原因。纵向体内生物发光成像和组织学染色显示，壳聚糖增强了植入的 BADSCs 的存活，并显著增加了 BADSCs 在体内向心肌细胞的分化率。此外，壳聚糖水凝胶递送的 BADSCs 防止了基质的不良重塑，增加了血管生成，并保持了心脏功能。这些结果表明，基于壳聚糖水凝胶和 BADSCs 的可注射心脏组织工程是一种有效的心肌再生策略。
