Temperature-responsive hydroxybutyl chitosan for the culture of mesenchymal stem cells and intervertebral disk cells
Temperature-responsive hydroxybutyl chitosan for the culture of mesenchymal stem cells and intervertebral disk cells
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DOI：
10.1016/j.biomaterials.2005.07.033
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发表时间：
2006-01-01
期刊：
影响因子：
14
通讯作者：
Leong, KW
中科院分区：
文献类型：
--
作者：
Dang, JM;Sun, DDN;Leong, KW
温度响应性聚合物是与生物活性治疗剂（例如干细胞）的可注射递送相关的应用的有吸引力的候选物。在这项研究中，我们评估了热敏性羟丁基壳聚糖（HBC）作为培养人间充质干细胞（hMSC）和椎间盘细胞的生物材料的潜力，最终目标是使用HBC聚合物作为可注射基质/细胞治疗剂。羟丁基基团与壳聚糖的缀合使得聚合物具有水溶性和热响应性。低于其较低的临界溶解温度，HBC溶液可以无限期地保持其溶剂化状态。在暴露于37摄氏度的环境后，在60秒内，3.8重量%的HBC溶液迅速形成可以用镊子覆盖的凝胶。在冷却时，凝胶能够再次恢复到其溶剂化状态。随着温度的升高，凝胶表现出G'和G”的显著增加，表明凝胶机械性能的温度依赖性增强。虽然凝胶化时为固体结构，但由于其聚合物相互作用和凝胶形成的物理性质，当暴露于高达10%应变的剪切应力时，凝胶表现出流体状粘弹性行为，随着剪切应力的增加，G'和G”均接近零。本研究中提出的HBC凝胶的配方具有范围从13.0至34.6摄氏度的凝胶化温度和67- 95%的水含量。在MSC和椎间盘细胞培养物中观察到最小的细胞毒性，这些聚合物的浓度高达5重量%。代谢活性的检测、合成mRNA的遗传分析以及这些凝胶中MSC和盘细胞培养物的组织学染色共同表明细胞增殖而没有代谢活性和细胞外基质产生的损失。这项研究表明，HBC凝胶作为一种可注射载体的潜力，为未来的应用提供治疗，以鼓励生物相关的重建退化的磁盘。(c)2005爱思唯尔有限公司保留所有权利。
Temperature-responsive polymers are attractive candidates for applications related to injectable delivery of biologically active therapeutics, such as stem cells. In this study, we evaluate the potential of thermosensitive hydroxybutyl chitosan (HBC) as a biomaterial for the culture of human mesenchymal stem cells (hMSC) and cells derived from the intervertebral disk, with the eventual goal of using the HBC polymer as an injectable matrix/cell therapeutic. Conjugation of hydroxybutyl groups to chitosan renders the polymer water soluble and thermally responsive. Below its lower critical solution temperature, a solution of HBC can be maintained indefinitely in its solvated state. Upon exposure to a 37 degrees C environment, within 60 s, a 3.8 wt% HBC solution rapidly forms a gel that can be maneuvered with forceps. Upon cooling, the gel once again is able to revert to its solvated state. The gel exhibits a dramatic increase in both G' and G" with increasing temperature, signifying a temperature-dependent enhancement of gel mechanical properties. Although a solid structure upon gelation, due to its physical nature of polymer interaction and gel formation, the gel exhibits a fluid-like viscoelastic behavior when exposed to shear stresses of up to 10% strain, with both G' and G" approaching zero with increasing shear stress. Formulations of HBC gels presented in this study have gelation temperatures ranging from 13.0 to 34.6 degrees C and water contents of 67-95%. Minimal cytotoxicity in MSC and disk cell cultures was observed with these polymers up to a concentration of 5 wt%. Detection of metabolic activity, genetic analysis of synthesized mRNA, and histological staining of MSC and disk cell cultures in these gels collectively indicate cell proliferation without a loss in metabolic activity and extracellular matrix production. This study suggests the potential of HBC gel as an injectable carrier for future applications of delivering therapeutics to encourage a biologically relevant reconstruction of the degenerated disk. (c) 2005 Elsevier Ltd. All rights reserved.