Key Lab of Biobased Polymer Materials of Shandong Provincial Education Department, College of Polymer Science and Engineering, Qingdao University of Science and Technology, Qingdao 266042, P. R. China.
College of Chemical Engineering, Qingdao University of Science and Technology, Qingdao 266042, P. R. China.
ACS Appl Mater Interfaces. 2024 Oct 23;16(42):56862-56873. doi: 10.1021/acsami.4c13588. Epub 2024 Oct 14.
Thermoplastic polyurethanes (TPUs) are one of the most appealing materials with extensive applications in biomedical fields due to their versatile mechanical properties and excellent biocompatibility. In response to the escalating challenges of bacterial infections, it is desirable to obtain TPUs with intrinsic antibacterial activity, particularly for application in biomedical devices and public places. Herein, a cationic main-/side-chain structure regulation strategy in the TPU hard segment was adopted to introduce and optimize the antibacterial activity. This was achieved by synthesizing two types of quaternary ammonium salts (QAS)-containing chain extenders, i.e., -methyl--alkyl-,-bis(2-hydroxyethyl) ammonium bromide (M, where represents the -alkyl chain length) and -dimethyl--alkyl--2,3-propylene glycol (D), from -methyldiethanolamine (MDEA) and 3-dimethylamino-1,2-propanediol (DMAD), respectively. Given the structural differences between M and D, main-chain-type PU-M and side-chain-type PU-D were subsequently obtained with QAS groups in the hard segment. The -alkyl chain length, QAS content, and main-/side-chain types were systematically investigated to optimize bactericidal properties. The results revealed that a long -alkyl chain (from C6 to C14) increased the antibacterial activity of the chain extenders and corresponding TPU films. Besides, side-chain-type PU-D films showed higher contact-active antibacterial activity than that exerted by the main-chain-type PU-M films. Remarkably, almost 100% of (. ) could be killed by the PU-D14 film with a low QAS content (1.6 wt %). All the TPUs showed good thermal stability with a degradation temperature of 5% mass loss () above 300 °C. Moreover, the TPU films displayed excellent mechanical properties with the tensile strength at break varying from 20.7 to 47.5 MPa and ultimate elongation above 1000%. All of the intrinsic antibacterial films showed negligible hemolytic activities.
热塑性聚氨酯（TPU）因其具有广泛的机械性能和出色的生物相容性而在生物医学领域得到广泛应用，是一种极具吸引力的材料。针对细菌感染不断加剧的挑战，人们希望获得具有内在抗菌活性的 TPU，特别是在生物医学器械和公共场所的应用中。在此，采用在 TPU 硬段中引入和优化抗菌活性的阳离子主链/侧链结构调控策略。通过合成两种含季铵盐（QAS）的扩链剂，即来自甲基二乙醇胺（MDEA）和 3-二甲基氨基-1,2-丙二醇（DMAD）的 -甲基--烷基-,-双（2-羟乙基）溴化铵（M，其中 代表 -烷基链长）和 -二甲基--烷基--2,3-丙二醇（D），实现了这一点。鉴于 M 和 D 的结构差异，随后在硬段中带有 QAS 基团得到了主链型 PU-M 和侧链型 PU-D。系统研究了 -烷基链长、QAS 含量和主链/侧链类型，以优化杀菌性能。结果表明，长 -烷基链（从 C6 到 C14）增加了扩链剂和相应 TPU 薄膜的抗菌活性。此外，侧链型 PU-D 薄膜比主链型 PU-M 薄膜表现出更高的接触活性抗菌活性。值得注意的是，具有低 QAS 含量（1.6wt%）的 PU-D14 薄膜几乎可以杀死 100%的 （ ）。所有 TPU 均表现出良好的热稳定性，5%质量损失时的降解温度（ ）均高于 300°C。此外，TPU 薄膜表现出优异的力学性能，断裂伸长率在 1000%以上，拉伸强度从 20.7 到 47.5 MPa 不等。所有具有内在抗菌活性的薄膜均表现出可忽略不计的溶血活性。
