Insomphun Chayatip, Chuah Jo-Ann, Kobayashi Shingo, Fujiki Tetsuya, Numata Keiji
Enzyme Research Team, RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan.
Kaneka Corporation, 1-8 Miyamae-cho, Takasago-cho, Takasago, Hyogo 676-8688, Japan.
ACS Biomater Sci Eng. 2017 Dec 11;3(12):3064-3075. doi: 10.1021/acsbiomaterials.6b00279. Epub 2016 Sep 1.
Polyhydroxyalkanoates (PHAs) are biopolyesters that have been studied as tissue engineering materials because of their biodegradability, biocompatibility, and low cytotoxicity. In this study, poly(3-hydroxybutyrate--3-hydroxyvalerate--2,3-dihydroxybutyrate) [PHBVDB] containing hydroxyl groups was produced by recombinant . were constructed to express the propionate-coenzymeA transferase () gene from , and glycolate was used as the carbon source. Disruption of encoding β-ketothiolase in the operon increased 2,3-dihydroxybutyrate (2,3-DHBA) compositions to 3 mol %. The PHBVDB film showed a lower water contact angle compared with other PHA films, indicating increased hydrophilicity due to the hydroxyl groups. The mechanical properties of the PHBVDB scaffold met the requirements for a soft tissue matrix. The effect of hydroxyl groups on cytotoxicity was evaluated with human mesenchymal stem cells. Results of cell proliferation and live/dead assays showed that the PHBVDB scaffold did not exhibit significant cytotoxicity toward the cells. These results indicate that PBVDB containing hydroxyl groups could be applied as a hydrophilicity-controlled scaffold for soft tissue engineering.
聚羟基脂肪酸酯（PHA）是一类生物聚酯，因其具有生物可降解性、生物相容性和低细胞毒性，已被作为组织工程材料进行研究。在本研究中，通过重组技术制备了含羟基的聚（3-羟基丁酸酯-3-羟基戊酸酯-2,3-二羟基丁酸酯）[PHBVDB]。构建了表达来自丙酸辅酶A转移酶（）基因的载体，并使用乙醇酸作为碳源。在操纵子中编码β-酮硫解酶的基因被破坏后，2,3-二羟基丁酸（2,3-DHBA）的组成增加到3摩尔%。与其他PHA薄膜相比，PHBVDB薄膜的水接触角更低，这表明由于羟基的存在，亲水性增强。PHBVDB支架的力学性能满足软组织基质的要求。用人骨髓间充质干细胞评估了羟基对细胞毒性的影响。细胞增殖和活/死检测结果表明，PHBVDB支架对细胞没有明显的细胞毒性。这些结果表明，含羟基的PBVDB可作为一种用于软组织工程的亲水性可控支架。
