The piezoelectricity of the biocompatible and biodegradable polymer polylactic acid (PLA) was investigated as a potential magnetoelectric (ME) nanocomposite for biomedical applications. A key focus was to quantify the piezoelectric properties of single PLA fibers while tuning their polymer degradability through the addition of faster degrading polymer, poly (DL-lactide-co-glycolide) (PLGA), which is not a piezoelectric polymer. Piezoresponse Force Microscopy (PFM) showed that electrospun PLA fibers gave a piezoelectric response of 186.0 ± 28.1 pm. For comparison both PLA/PLGA (75/25) and PLA/PLGA (50/50) fibers gave significantly lower piezoelectric responses of 88.8 ± 12.3 pm and 49.6 ± 9.1 pm, respectively. For the highest content PLGA fibers, PLA/PLGA (25/75), only very few fibers exhibited a low response of 28.8 pm while most showed no response. Overall, an increasing PLGA content caused a decrease in the piezoelectric response, thus an expected trade-off existed between the biodegradability (i.e. PLA to PLGA content ratio) versus piezoelectricity. The findings were considered significant due to the existence of piezoelectricity in a tuneable biodegradable material that has potential to impart piezoelectric induced effects on biointeractions with the surrounding biological environment or drug interactions with the polymer to control the rate of drug release. In such applications, there is an opportunity to magnetically control the piezoelectricity and henceforth PLA/CoFe2O4 ME nanocomposite fibers with 5% and 10% of CoFe2O4 nanoparticles were also investigated. Both 5% and 10% PLA/CoFe2O4 nanocomposites gave lower piezoelectric responses compared to the PLA presumably due to the disturbance of polymer chains and dipole moments by the magnetic nanoparticles, in addition to effects from the possible inhomogeneous distribution of CoFe2O4 nanoparticles.

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通过压电响应力显微镜观察可生物降解 PLA 基复合纤维的纳米级压电效应

生物相容性和可生物降解的聚合物聚乳酸 (PLA) 的压电性被研究为用于生物医学应用的潜在磁电 (ME) 纳米复合材料。一个关键的重点是量化单个 PLA 纤维的压电性能，同时通过添加降解速度更快的聚合物聚（DL-丙交酯-共-乙交酯）（PLGA）来调整其聚合物的降解性，该聚合物不是压电聚合物。压电响应力显微镜 (PFM) 显示电纺 PLA 纤维的压电响应为 186.0 ± 28.1 pm。为了比较，PLA/PLGA (75/25) 和 PLA/PLGA (50/50) 纤维分别给出了显着较低的压电响应，分别为 88.8 ± 12.3 pm 和 49.6 ± 9.1 pm。对于含量最高的 PLGA 纤维 PLA/PLGA (25/75)，只有极少数纤维表现出 28 的低响应。晚上8点，而大多数人没有回应。总体而言，PLGA 含量的增加导致压电响应的降低，因此在生物降解性（即 PLA 与 PLGA 的含量比）与压电性之间存在预期的权衡。由于在可调节的生物可降解材料中存在压电效应，因此该发现被认为具有重要意义，该材料有可能对与周围生物环境的生物相互作用或药物与聚合物的相互作用产生压电诱导效应，以控制药物释放速率。在这些应用中，有机会磁性控制压电性，因此也研究了含有 5% 和 10% CoFe2O4 纳米颗粒的 PLA/CoFe2O4 ME 纳米复合纤维。