Non-invasive acoustic fabrication methods to enhance collagen hydrogel bioactivity.
Non-invasive acoustic fabrication methods to enhance collagen hydrogel bioactivity.
复制标题
增强胶原水凝胶生物活性的非侵入性声学制造方法。
DOI：
10.1088/2053-1591/ab597a
复制
发表时间：
2019
影响因子：
2.3
通讯作者：
Hocking,DeniseC
中科院分区：
文献类型：
--
作者：
Norris,EmmaG;Majeski,Joseph;Wayson,SarahE;Coleman,Holly;Choe,Regine;Dalecki,Diane;Hocking,DeniseC
最近，人们的注意力集中在利用细胞外基质 (ECM) 成分作为各种组织工程应用和再生医学疗法的天然构建块上。因此，人们正在寻求新的制造方法来实现对 ECM 分子结构特征的分子控制，以改善其生物功能。将可溶性胶原蛋白暴露于与超声波传播相关的声力下，会产生胶原微纤维组织的局部变化，进而促进组织再生所必需的细胞行为，包括细胞迁移和基质重塑。在本研究中，研究了超声波与聚合胶原相互作用以产生胶原微结构功能变化的机制。通过调节胶原蛋白溶液的pH值和凝胶聚合的温度来控制胶原蛋白聚合的速率。结果表明，I 型胶原蛋白从液体到凝胶的相变引发了声吸收的同时增加。胶原蛋白的这种相变涉及早期胶原微纤维的横向生长，重要的是，对应于一段规定的时间，在此期间暴露于超声波会给所得胶原水凝胶带来结构和功能的变化。总之，这些实验隔离了胶原纤维组装过程中的一个关键窗口，在此期间与超声波传播相关的机械力可有效产生结构变化，而结构变化是声学改性胶原水凝胶刺激细胞迁移能力的基础。这些结果表明，与胶原聚合相关的材料特性的变化是声力改变胶原生物材料以增强生物功能的机制的基本组成部分。
Much attention has focused recently on utilizing components of the extracellular matrix (ECM) as natural building blocks for a variety of tissue engineering applications and regenerative medicine therapies. Consequently, new fabrication methods are being sought to enable molecular control over the structural characteristics of ECM molecules in order to improve their biological function. Exposing soluble collagen to acoustic forces associated with ultrasound propagation produces localized variations in collagen microfiber organization that in turn, promote cell behaviors essential for tissue regeneration, including cell migration and matrix remodeling. In the present study, mechanisms by which ultrasound interacts with polymerizing collagen to produce functional changes in collagen microstructure were investigated. The rate of collagen polymerization was manipulated by adjusting the pH of collagen solutions and the temperature at which gels were polymerized. Results demonstrate that the phase transition of type I collagen from fluid to gel triggered a simultaneous increase in acoustic absorption. This phase transition of collagen involves the lateral growth of early-stage collagen microfibrils and importantly, corresponded to a defined period of time during which exposure to ultrasound introduced both structural and functional changes to the resultant collagen hydrogels. Together, these experiments isolated a critical window in the collagen fiber assembly process during which mechanical forces associated with ultrasound propagation are effective in producing structural changes that underlie the ability of acoustically-modified collagen hydrogels to stimulate cell migration. These results demonstrate that changes in material properties associated with collagen polymerization are a fundamental component of the mechanism by which acoustic forces modify collagen biomaterials to enhance biological function.