Xeltis B.V., De Lismortel 31, 5612 AR Eindhoven, The Netherlands; Eindhoven University of Technology, Department of Biomedical Engineering, PO Box 513, 5600 MB Eindhoven, The Netherlands.
SyMO-Chem B.V., Den Dolech 2, 5612 AZ Eindhoven, The Netherlands.
Acta Biomater. 2015 Nov;27:21-31. doi: 10.1016/j.actbio.2015.08.034. Epub 2015 Aug 24.
The emerging field of in situ tissue engineering (TE) of load bearing tissues places high demands on the implanted scaffolds, as these scaffolds should provide mechanical stability immediately upon implantation. The new class of synthetic supramolecular biomaterial polymers, which contain non-covalent interactions between the polymer chains, thereby forming complex 3D structures by self assembly. Here, we have aimed to map the degradation characteristics of promising (supramolecular) materials, by using a combination of in vitro tests. The selected biomaterials were all polycaprolactones (PCLs), either conventional and unmodified PCL, or PCL with supramolecular hydrogen bonding moieties (either 2-ureido-[1H]-pyrimidin-4-one or bis-urea units) incorporated into the backbone. As these materials are elastomeric, they are suitable candidates for cardiovascular TE applications. Electrospun scaffold strips of these materials were incubated with solutions containing enzymes that catalyze hydrolysis, or solutions containing oxidative species. At several time points, chemical, morphological, and mechanical properties were investigated. It was demonstrated that conventional and supramolecular PCL-based polymers respond differently to enzyme-accelerated hydrolytic or oxidative degradation, depending on the morphological and chemical composition of the material. Conventional PCL is more prone to hydrolytic enzymatic degradation as compared to the investigated supramolecular materials, while, in contrast, the latter materials are more susceptible to oxidative degradation. Given the observed degradation pathways of the examined materials, we are able to tailor degradation characteristics by combining selected PCL backbones with additional supramolecular moieties. The presented combination of in vitro test methods can be employed to screen, limit, and select biomaterials for pre-clinical in vivo studies targeted to different clinical applications.
新兴的负载组织原位组织工程（TE）领域对植入支架提出了很高的要求，因为这些支架应该在植入后立即提供机械稳定性。新型合成超分子生物材料聚合物包含聚合物链之间的非共价相互作用，从而通过自组装形成复杂的 3D 结构。在这里，我们旨在通过使用体外测试组合来绘制有前途的（超分子）材料的降解特性。选择的生物材料均为聚己内酯（PCL），包括常规和未改性的 PCL，或在主链中掺入超分子氢键部分（2-脒基-[1H]-嘧啶-4-酮或双脲基）的 PCL。由于这些材料具有弹性，因此它们是心血管 TE 应用的合适候选材料。这些材料的静电纺丝支架条在含有催化水解的酶的溶液或含有氧化物质的溶液中孵育。在几个时间点，研究了化学，形态和机械性能。结果表明，常规和基于超分子的 PCL 聚合物对酶加速的水解或氧化降解的反应不同，这取决于材料的形态和化学组成。与研究的超分子材料相比，常规 PCL 更容易发生酶促水解降解，而另一方面，后一种材料更容易发生氧化降解。鉴于所检查材料的观察到的降解途径，我们可以通过将选定的 PCL 主链与其他超分子部分结合来定制降解特性。所提出的体外测试方法组合可用于筛选，限制和选择针对不同临床应用的临床前体内研究的生物材料。
