间充质基质细胞(MSC)获自人骨髓并在补充了人血小板裂解物的培养物中扩增。一旦半汇合,将细胞接种在固体胶原支架中,所述固体胶原支架被产生3D细胞支架的细胞快速定殖。这里,他们获得了肌成纤维细胞表型,当暴露于适当的化学刺激时,发达的张力和细胞缩短,类似于横纹肌和平滑肌细胞。肌成纤维细胞含有分子马达-非肌肉肌球蛋白IIA型(NMMIIA),其跨桥(CB)动力学与横纹肌和平滑肌肌球蛋白相比显着缓慢。使用Huxley方程确定NMMIIA的分子机械性能。感谢大量的NMMIIA分子,我们确定了MSCs的统计力学(SM),使用大规范集成,这使得有可能计算各种热力学实体,如化学亲和力,统计熵,内部能量,热力学流动,热力学力,和熵生产率。在热力学力和热力学流动之间观察到的线性关系允许建立在胶原支架中的MSC-负载处于接近平衡的稳定状态(亲和力^RT),还将MSC接种在用三肽Arg-Gly-Asp(RGD)官能化的固体胶原支架中。这引起了NMMIIASM的重大变化,特别是通过增加熵产生率。总之,充满MSC的胶原支架可以被视为在接近平衡的线性状态下运行的非肌肉收缩生物工程组织。其SM可以基本上被RGD肽修饰。
Mesenchymal stromal cells (MSCs) were obtained from human bone marrow and amplified in cultures supplemented with human platelet lysate. Once semi-confluent, cells were seeded in solid collagen scaffolds that were rapidly colonized by the cells generating a 3D cell scaffold. Here, they acquired a myofibroblast phenotype and when exposed to appropriate chemical stimulus, developed tension and cell shortening, similar to those of striated and smooth muscle cells. Myofibroblasts contained a molecular motor-the non-muscle myosin type IIA (NMMIIA) whose crossbridge (CB) kinetics are dramatically slow compared with striated and smooth muscle myosins. Huxley\'s equations were used to determine the molecular mechanical properties of NMMIIA. Thank to the great number of NMMIIA molecules, we determined the statistical mechanics (SM) of MSCs, using the grand canonical ensemble which made it possible to calculate various thermodynamic entities such as the chemical affinity, statistical entropy, internal energy, thermodynamic flow, thermodynamic force, and entropy production rate. The linear relationship observed between the thermodynamic force and the thermodynamic flow allowed to establish that MSC-laden in collagen scaffolds were in a near-equilibrium stationary state (affinity ≪ RT), MSCs were also seeded in solid collagen scaffolds functionalized with the tripeptide Arg-Gly-Asp (RGD). This induced major changes in NMMIIA SM particularly by increasing the rate of entropy production. In conclusion, collagen scaffolds laden with MSCs can be viewed as a non-muscle contractile bioengineered tissue operating in a near-equilibrium linear regime, whose SM could be substantially modified by the RGD peptide.