Alves Marta M, Cunha Diana V, Santos Catarina F, Mira Nuno P, Montemor Maria F
CQE Instituto Superior Técnico, Departamento de Engenharia Química, Universidade de Lisboa, Av. Rovisco Pais 1049-001, Lisboa, Portugal.
J Mater Chem B. 2016 Jul 21;4(27):4754-4761. doi: 10.1039/c6tb00797j. Epub 2016 Jun 27.
Rejection and colonization by microbes are two problematic issues that often require the surgical removal of medical implants with increased risks for patients. In this work it is shown that functionalization of Zn surfaces with ZnO-nanostructured 'Anastacia' flowers (NAF) resulted in improved biomaterials that can potentially overcome these important drawbacks, which can further boost the use of Zn in biomedical implants. The in vitro degradation of NAF-coated Zn under simulated physiological conditions resulted in the formation of a biomimetic corrosion layer rich in a hydroxyapatite analogue that, being an important bone component, may potentially decrease implant rejection. Colonization of the NAF-coated Zn surface by Candida parapsilosis and Candida albicans, two of the more relevant microbial species colonizing medical devices, was significantly reduced on the NAF-coated Zn surface. The mechanism by which this colonization inhibition occurred was distinct since for C. parapsilosis cells this was attributed to reduced cell viability, while for C. albicans the reduced colonization was related to impaired biofilm formation. This ZnO-derived coating is an expeditious strategy to improve the resilience of Zn-based resorbable biomaterials towards Candida spp. colonization, paving the way for the design of bioactive ZnO-derived coatings with potential for clinical applications on bone.
微生物的排斥和定植是两个棘手的问题，通常需要通过手术移除医用植入物，这会增加患者的风险。在这项工作中，研究表明，用ZnO纳米结构的“阿纳斯塔西娅”花（NAF）对锌表面进行功能化处理，可得到性能改善的生物材料，有望克服这些重要缺点，进而推动锌在生物医学植入物中的应用。在模拟生理条件下，涂覆有NAF的锌的体外降解导致形成富含羟基磷灰石类似物的仿生腐蚀层，而羟基磷灰石作为一种重要的骨成分，可能会降低植入物的排斥反应。在医用设备上定植的两种较为常见的微生物——近平滑念珠菌和白色念珠菌，在涂覆有NAF的锌表面的定植显著减少。这种定植抑制发生的机制有所不同，对于近平滑念珠菌细胞而言，这归因于细胞活力降低，而对于白色念珠菌，定植减少与生物膜形成受损有关。这种源自氧化锌的涂层是一种提高锌基可吸收生物材料对念珠菌属定植的耐受性的快速策略，为设计具有骨临床应用潜力的生物活性氧化锌衍生涂层铺平了道路。
