Biocompatible, degradable thermoplastic polyurethane based on polycaprolactone-block-polytetrahydrofuran-block-polycaprolactone copolymers for soft tissue engineering.
Biocompatible, degradable thermoplastic polyurethane based on polycaprolactone-block-polytetrahydrofuran-block-polycaprolactone copolymers for soft tissue engineering.
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用于软组织工程的基于聚己内酯-嵌段-聚四氢呋喃-嵌段-聚己内酯共聚物的生物相容性可降解热塑性聚氨酯
DOI：
10.1039/c7tb00419b
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发表时间：
2017-06-14
期刊：
影响因子：
--
通讯作者：
Turng LS
中科院分区：
文献类型：
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作者：
Mi HY;Jing X;Napiwocki BN;Hagerty BS;Chen G;Turng LS
可生物降解的合成聚合物作为组织工程支架材料已得到广泛应用。尽管它们表现出了良好的生物相容性，但由于存在大量刚性酯键，它们未能像软组织那样具有低刚度和高弹性。本文以聚酯醚三嵌段共聚物（聚己内酯-嵌段-聚四氢呋喃-嵌段-聚己内酯三嵌段共聚物PCTC）为软段，脂肪族二异氰酸酯（六亚甲基二异氰酸酯，HDI）为硬段，可降解二醇（双（2-羟乙基）对苯二甲酸乙二醇酯，BET）为扩链剂，合成了新型热塑性聚氨酯弹性体CTC-PU（BET）。PCTC抑制了CTC-PU（BET）的结晶，降低了BET的熔融温度，与传统聚酯基生物可降解tpu相比，BET显著提高了CTC-PU的热分解和水解降解速率。本研究合成的CTC-PU（BET）具有较低的拉伸模量和拉伸强度，分别为2.2 MPa和1.3 MPa，断裂伸长率超过700%。同时，在10次加载和卸载循环中，其恢复率保持在95.3%，恢复力保持在90%。此外，TPU可以被静电纺丝成随机和排列的纤维支架，由主要的微纤维和纳米分支组成。3T3成纤维细胞培养证实，这些支架在底物-细胞相互作用和细胞增殖方面优于传统的可生物降解TPU支架。考虑到该TPU易于合成、成本低、刚度低、弹性高、降解率可控、易加工、生物相容性好等优点，其作为软组织再生的组织工程支架材料具有广阔的应用前景。
Biodegradable synthetic polymers have been widely used as tissue engineering scaffold materials. Even though they have shown excellent biocompatibility, they have failed to resemble the low stiffness and high elasticity of soft tissues because of the presence of massive rigid ester bonds. Herein, we synthesized a new thermoplastic polyurethane elastomer (CTC-PU(BET)) using poly ester ether triblock copolymer (polycaprolactone-block-polytetrahydrofuran-block-polycaprolactone triblock copolymer, PCTC) as the soft segment, aliphatic diisocyanate (hexamethylene diisocyanate, HDI) as the hard segment, and degradable diol (bis(2-hydroxyethyl) terephthalate, BET) as the chain extender. PCTC inhibited crystallization and reduced the melting temperature of CTC-PU(BET), and BET dramatically enhanced the thermal decomposition and hydrolytic degradation rate when compared with conventional polyester-based biodegradable TPUs. The CTC-PU(BET) synthesized in this study possessed a low tensile modulus and tensile strength of 2.2 MPa and 1.3 MPa, respectively, and an elongation-at-break over 700%. Meanwhile, it maintained a 95.3% recovery rate and 90% resilience over ten cycles of loading and unloading. In addition, the TPU could be electrospun into both random and aligned fibrous scaffolds consisting of major microfibers and nanobranches. 3T3 fibroblast cell culture confirmed that these scaffolds outperformed the conventional biodegradable TPU scaffolds in terms of substrate–cellular interactions and cell proliferation. Considering the advantages of this TPU, such as ease of synthesis, low cost, low stiffness, high elasticity, controllable degradation rate, ease of processability, and excellent biocompatibility, it has great prospects to be used as a tissue engineering scaffold material for soft tissue regeneration.