1 Biomaterials and Tissue Engineering, UCL Eastman Dental Institute, University College London, London, UK.
2 Centre for Inflammation and Tissue Repair, UCL Respiratory, Division of Medicine, Faculty of Medical Sciences, University College London, London, UK.
J Dent Res. 2017 Jul;96(8):917-923. doi: 10.1177/0022034517706354. Epub 2017 May 1.
Denture-associated stomatitis is a common candidal infection that may give rise to painful oral symptoms, as well as be a reservoir for infection at other sites of the body. As poly (methyl methacrylate) (PMMA) remains the main material employed in the fabrication of dentures, the aim of this research was to evaluate the adhesion of Candida albicans cells onto PMMA surfaces by employing an atomic force microscopy (AFM) single-cell force spectroscopy (SCFS) technique. For experiments, tipless AFM cantilevers were functionalized with PMMA microspheres and probed against C. albicans cells immobilized onto biopolymer-coated substrates. Both a laboratory strain and a clinical isolate of C. albicans were used for SCFS experiments. Scanning electron microscopy (SEM) and AFM imaging of C. albicans confirmed the polymorphic behavior of both strains, which was dependent on growth culture conditions. AFM force-spectroscopy results showed that the adhesion of C. albicans to PMMA is morphology dependent, as hyphal tubes had increased adhesion compared with yeast cells ( P < 0.05). C. albicans budding mother cells were found to be nonadherent, which contrasts with the increased adhesion observed in the tube region. Comparison between strains demonstrated increased adhesion forces for a clinical isolate compared with the lab strain. The clinical isolate also had increased survival in blood and reduced sensitivity to complement opsonization, providing additional evidence of strain-dependent differences in Candida-host interactions that may affect virulence. In conclusion, PMMA-modified AFM probes have shown to be a reliable technique to characterize the adhesion of C. albicans to acrylic surfaces.
义齿相关性口炎是一种常见的念珠菌感染，可能导致口腔疼痛症状，并成为身体其他部位感染的储库。由于聚甲基丙烯酸甲酯（PMMA）仍然是制作义齿的主要材料，因此本研究旨在通过原子力显微镜（AFM）单细胞力谱（SCFS）技术评估白色念珠菌细胞在 PMMA 表面的粘附。在实验中，无尖端的 AFM 悬臂被 PMMA 微球功能化，并探测固定在生物聚合物涂层基底上的白色念珠菌细胞。SCFS 实验使用了实验室菌株和临床分离株的白色念珠菌。扫描电子显微镜（SEM）和白色念珠菌的 AFM 成像证实了两种菌株的多态性行为，这取决于生长培养条件。AFM 力谱结果表明，白色念珠菌与 PMMA 的粘附具有形态依赖性，因为菌丝管的粘附性比酵母细胞强（P<0.05）。发现白色念珠菌出芽母细胞不粘附，这与在管区观察到的增加的粘附相反。与菌株的比较表明，与实验室菌株相比，临床分离株的粘附力增加。临床分离株在血液中的存活率也增加，对补体调理的敏感性降低，这为白色念珠菌-宿主相互作用中与菌株相关的差异提供了额外的证据，这些差异可能影响毒力。总之，PMMA 修饰的 AFM 探针已被证明是一种可靠的技术，可用于表征白色念珠菌对丙烯酸表面的粘附。
