Khan Mohd Sajjad Ahmad
Department of Basic Sciences, Deanship of Preparatory Year and Supporting Studies, Imam Abdulrahman Bin Faisal University, P.O. Box 1982, Dammam 34212, Saudi Arabia.
Pharm Nanotechnol. 2024 Aug 28. doi: 10.2174/0122117385318008240816043647.
Increased intake of drugs worldwide and the subsequent advent of resistance to existing antibiotics have globally threatened health organizations. To combat the problem of these drug-resistant infections, as an alternative approach, graphene (GN)-related nanomaterials have attracted significant interest because of their effective anti-microbial potential. The present study shows the synthesis and characterization of nanocomposite of GN with carbon nitride viz. g- C3N4, g-C3N4-Cu, and GN@g-C3N4-Cu. Further, we investigated the anti-microbial potential of these nanocomposites against strains of Gram-negative and Gram-positive bacteria, viz., a multidrug- resistant strain of Pseudomonas aeruginosa (MDRPA), a methicillin-resistant strain of Staphylococcus aureus ATCC33593 (MRSA), and an azole-sensitive fungal strain (Candida albicans ATCC14053).
The morphological characterization of GN@g-C3N4-Cu nanocomposite was executed by scanning electron microscopy, whereas the elemental analysis and their distribution were studied by energy-dispersive X-ray spectroscopy and elemental mapping methods. Furthermore, the anti-microbial and antibiofilm efficacies of g-C3N4, g-C3N4-Cu, and GN@g-C3N4-Cu nanocomposites were evaluated by disc diffusion, two-fold serial micro broth dilution, and 96 well microtiter plate methods.
The ternary g-C3N4-Cu@GN, apart from the structures of g-C3N4-Cu, showed big sheets of GN. The observance of C, N, O, and Cu in the elemental analysis, as well as their uniform distribution in the mapping, indicated the successful fabrication of g-C3N4-Cu@GN. GN@g-C3N4-Cu followed by g-C3N4-Cu and (g-C3N4) exhibited significantly higher antimicrobial activity (zone of inhibition from 14.33 to 49.33 mm) against both the drug-resistant bacterial strains and azole-sensitive C. albicans. MICs of nanocomposites ranged from 32 -256 μg/ml against the tested strains. Whereas all three nanocomposites at sub-MICs (0.25 A- and 0.5 A- MICs) showed concentration- dependent inhibition of biofilm formation in MDRPA, MRSA, and C. albicans by allowing 11.35% to 32.59% biofilm formation.
Our study highlights the enhanced efficiency of GN@g-C3N4-Cu nanocomposites as potential anti-microbial and antibiofilm agents to overcome the challenges of multi-drug-resistant bacteria and azole-sensitive fungi. Such kind of nanocomposites could be used to prevent nosocomial infections if coated on medical devices and food manufacturing instruments.
全球范围内药物摄入量的增加以及随之而来的对现有抗生素的耐药性出现，已对全球卫生组织构成威胁。为应对这些耐药性感染问题，作为一种替代方法，石墨烯（GN）相关的纳米材料因其有效的抗菌潜力而引起了广泛关注。本研究展示了GN与氮化碳即g-C3N4、g-C3N4-Cu和GN@g-C3N4-Cu的纳米复合材料的合成与表征。此外，我们研究了这些纳米复合材料对革兰氏阴性菌和革兰氏阳性菌菌株的抗菌潜力，即多重耐药铜绿假单胞菌（MDRPA）、耐甲氧西林金黄色葡萄球菌ATCC33593（MRSA）以及对唑敏感的真菌菌株（白色念珠菌ATCC14053）。
通过扫描电子显微镜对GN@g-C3N4-Cu纳米复合材料进行形态表征，而通过能量色散X射线光谱和元素映射方法研究元素分析及其分布。此外，采用纸片扩散法、两倍系列微量肉汤稀释法和96孔微量滴定板法评估g-C3N4、g-C3N4-Cu和GN@g-C3N4-Cu纳米复合材料的抗菌和抗生物膜效果。
除了g-C3N4-Cu的结构外，三元g-C3N4-Cu@GN还显示出大片的GN。元素分析中观察到C、N、O和Cu，以及它们在映射中的均匀分布，表明g-C3N4-Cu@GN的成功制备。GN@g-C3N4-Cu其次是g-C3N4-Cu和（g-C3N4）对耐药细菌菌株和对唑敏感的白色念珠菌均表现出显著更高的抗菌活性（抑菌圈为14.33至49.33毫米）。纳米复合材料对测试菌株的最低抑菌浓度范围为32 - 256μg/ml。而所有三种纳米复合材料在亚最低抑菌浓度（0.25倍和0.5倍最低抑菌浓度）下，通过允许11.35%至32.59%的生物膜形成，对MDRPA、MRSA和白色念珠菌的生物膜形成表现出浓度依赖性抑制。
我们的研究强调了GN@g-C3N4-Cu纳米复合材料作为潜在的抗菌和抗生物膜剂在克服多重耐药细菌和对唑敏感真菌挑战方面的增强效率。如果涂覆在医疗设备和食品制造仪器上，这种纳米复合材料可用于预防医院感染。
