Department of Mechanical Engineering, College of Engineering and Mathematical Sciences, University of Vermont, Burlington, VT 05405, USA.
Centre for Bioengineering and Nanomedicine, Department of Food Science, University of Otago, Dunedin 9054, New Zealand.
J Mech Behav Biomed Mater. 2019 Feb;90:191-201. doi: 10.1016/j.jmbbm.2018.10.009. Epub 2018 Oct 12.
Injectable hydrogel systems are useful in many biomedical applications, including drug or cell delivery carriers and scaffolds. Here, we describe the design and characterization of a shear thinning hydrogel that undergoes a disassembly when shear forces are applied during injection and is self-healing once the shear forces are removed. This hydrogel is based on a cyclodextrin modified alginate, and a methacrylated gelatin which initially forms through a weak guest-host interaction between hydrophobic cyclodextrin cavities and the aromatic residue of gelatin. Methacrylated gelatin possesses photocrosslinkable functionalities which can go through a light-initiated polymerization to create secondary crosslinking sites and further crosslink the matrix. The shear thinning and self-healing behavior of these gels monitored in low and high strain range, viscosity of the hydrogels components and gelation kinetic were studied. The rheological analyses showed the formation of shear thinning gels which were further stabilized by visible light exposure. The cytotoxicity of the hydrogels towards human mesenchymal stem cells were assessed and the rate of mass loss over a week period was studied.
可注射水凝胶系统在许多生物医学应用中非常有用，包括药物或细胞输送载体和支架。在这里，我们描述了一种剪切变稀水凝胶的设计和特性，当在注射过程中施加剪切力时，该水凝胶会发生解体，一旦去除剪切力，它就会自我修复。这种水凝胶基于环糊精修饰的海藻酸钠和甲基丙烯酰化明胶，甲基丙烯酰化明胶最初通过疏水环糊精腔和明胶的芳基残基之间的弱主客体相互作用形成。甲基丙烯酰化明胶具有光交联官能团，可通过光引发聚合形成二级交联点，并进一步交联基质。在低应变和高应变范围内监测这些凝胶的剪切稀释和自修复行为，研究了水凝胶成分的粘度和凝胶化动力学。流变分析表明形成了剪切稀释凝胶，进一步通过可见光暴露稳定。评估了水凝胶对人骨髓间充质干细胞的细胞毒性，并研究了一周内质量损失的速率。
