Pérez-Davila Sara, González-Rodríguez Laura, Lama Raquel, López-Álvarez Miriam, Oliveira Ana Leite, Serra Julia, Novoa Beatriz, Figueras Antonio, González Pío
CINTECX, Universidade de Vigo, Grupo de Novos Materiais, 36310 Vigo, Spain.
Galicia Sur Health Research Institute (IIS Galicia Sur), SERGAS-UVIGO, 36213 Vigo, Spain.
Polymers (Basel). 2022 Oct 1;14(19):4117. doi: 10.3390/polym14194117.
Polylactic acid (PLA) has become one of the most commonly used polymers in medical devices given its biocompatible, biodegradable and bioabsorbable properties. In addition, due to PLA's thermoplastic behaviour, these medical devices are now obtained using 3D printing technologies. Once obtained, the 3D-printed PLA devices undergo different sterilisation procedures, which are essential to prevent infections. This work was an in-depth study of the physicochemical changes caused by novel and conventional sterilisation techniques on 3D-printed PLA and their impact on the biological response in terms of toxicity. The 3D-printed PLA physicochemical (XPS, FTIR, DSC, XRD) and mechanical properties as well as the hydrophilic degree were evaluated after sterilisation using saturated steam (SS), low temperature steam with formaldehyde (LTSF), gamma irradiation (GR), hydrogen peroxide gas plasma (HPGP) and CO under critical conditions (SCCO). The biological response was tested in vitro (fibroblasts NCTC-929) and in vivo (embryos and larvae wild-type zebrafish ). The results indicated that after GR sterilisation, PLA preserved the O:C ratio and the semi-crystalline structure. Significant changes in the polymer surface were found after HPGP, LTSF and SS sterilisations, with a decrease in the O:C ratio. Moreover, the FTIR, DSC and XRD analysis revealed PLA crystallisation after SS sterilisation, with a 52.9% increase in the crystallinity index. This structural change was also reflected in the mechanical properties and wettability. An increase in crystallinity was also observed after SCCO and LTSF sterilisations, although to a lesser extent. Despite these changes, the biological evaluation revealed that none of the techniques were shown to promote the release of toxic compounds or PLA modifications with toxicity effects. GR sterilisation was concluded as the least reactive technique with good perspectives in the biological response, not only at the level of toxicity but at all levels, since the 3D-printed PLA remained almost unaltered.
聚乳酸(PLA)因其生物相容性、可生物降解和可生物吸收的特性,已成为医疗设备中最常用的聚合物之一。此外,由于PLA的热塑性行为,现在这些医疗设备是使用3D打印技术制造的。一旦制造出来,3D打印的PLA设备要经过不同的灭菌程序,这对于预防感染至关重要。这项工作是对新型和传统灭菌技术对3D打印PLA造成的物理化学变化及其对毒性方面生物反应的影响进行的深入研究。使用饱和蒸汽(SS)、低温甲醛蒸汽(LTSF)、伽马射线辐照(GR)、过氧化氢气体等离子体(HPGP)和临界条件下的CO2(SCCO2)进行灭菌后,评估了3D打印PLA的物理化学性质(XPS、FTIR、DSC、XRD)、机械性能以及亲水性程度。在体外(成纤维细胞NCTC - 929)和体内(野生型斑马鱼胚胎和幼虫)测试了生物反应。结果表明,GR灭菌后,PLA保留了O:C比和半结晶结构。HPGP、LTSF和SS灭菌后,聚合物表面有显著变化,O:C比降低。此外,FTIR、DSC和XRD分析表明,SS灭菌后PLA发生结晶,结晶度指数增加了52.9%。这种结构变化也反映在机械性能和润湿性上。SCCO2和LTSF灭菌后也观察到结晶度增加,尽管程度较小。尽管有这些变化,但生物评估表明,没有一种技术显示会促进有毒化合物的释放或产生具有毒性作用的PLA改性。得出结论,GR灭菌是反应最小的技术,在生物反应方面前景良好,不仅在毒性水平,而且在所有层面都是如此,因为3D打印的PLA几乎保持不变。