Niemirowicz Katarzyna, Surel Urszula, Wilczewska Agnieszka Z, Mystkowska Joanna, Piktel Ewelina, Gu Xiaobo, Namiot Zbigniew, Kułakowska Alina, Savage Paul B, Bucki Robert
Department of Microbiological and Nanobiomedical Engineering, Medical University of Bialystok, Mickiewicza 2c, 15-222, Bialystok, Poland.
Institute of Chemistry, University of Bialystok, 1 Hurtowa, 15-399, Bialystok, Poland.
J Nanobiotechnology. 2015 May 1;13:32. doi: 10.1186/s12951-015-0093-5.
Ceragenins, synthetic mimics of endogenous antibacterial peptides, are promising candidate antimicrobial agents. However, in some settings their strong bactericidal activity is associated with toxicity towards host cells. To modulate ceragenin CSA-13 antibacterial activity and biocompatibility, CSA-13-coated magnetic nanoparticles (MNP-CSA-13) were synthesized. Transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) were used to characterize MNP-CSA-13 physicochemical properties. Bactericidal action and ability of these new compounds to prevent Pseudomonas. aeruginosa biofilm formation were assessed using a bacteria killing assay and crystal violet staining, respectively. Release of hemoglobin from human red blood cells was measured to evaluate MNP-CSA-13 hemolytic activity. In addition, we used surface activity measurements to monitor CSA-13 release from the MNP shell. Zeta potentials of P. aeruginosa cells and MNP-CSA-13 were determined to assess the interactions between the bacteria and nanoparticles. Morphology of P. aeruginosa subjected to MNP-CSA-13 treatment was evaluated using atomic force microscopy (AFM) to determine structural changes indicative of bactericidal activity.
Our studies revealed that the MNP-CSA-13 nanosystem is stable and may be used as a pH control system to release CSA-13. MNP-CSA-13 exhibits strong antibacterial activity, and the ability to prevent bacteria biofilm formation in different body fluids. Additionally, a significant decrease in CSA-13 hemolytic activity was observed when the molecule was immobilized on the nanoparticle surface.
Our results demonstrate that CSA-13 retains bactericidal activity when immobilized on a MNP while biocompatibility increases when CSA-13 is covalently attached to the nanoparticle.
壳聚糖，内源性抗菌肽的合成模拟物，是很有前景的抗菌剂候选物。然而，在某些情况下，它们强大的杀菌活性与对宿主细胞的毒性相关。为了调节壳聚糖CSA - 13的抗菌活性和生物相容性，合成了CSA - 13包覆的磁性纳米颗粒（MNP - CSA - 13）。使用透射电子显微镜（TEM）、傅里叶变换红外光谱（FT - IR）、差示扫描量热法（DSC）和热重分析（TGA）对MNP - CSA - 13的物理化学性质进行表征。分别使用细菌杀伤试验和结晶紫染色评估这些新化合物的杀菌作用以及预防铜绿假单胞菌生物膜形成的能力。测量人红细胞中血红蛋白的释放以评估MNP - CSA - 13的溶血活性。此外，我们使用表面活性测量来监测CSA - 13从MNP壳中的释放。测定铜绿假单胞菌细胞和MNP - CSA - 13的zeta电位以评估细菌与纳米颗粒之间的相互作用。使用原子力显微镜（AFM）评估经MNP - CSA - 13处理的铜绿假单胞菌的形态，以确定指示杀菌活性的结构变化。
我们的研究表明，MNP - CSA - 13纳米系统是稳定的，可作为pH控制系统用于释放CSA - 13。MNP - CSA - 13表现出强大的抗菌活性，以及在不同体液中预防细菌生物膜形成的能力。此外，当该分子固定在纳米颗粒表面时，观察到CSA - 13的溶血活性显著降低。
我们的结果表明，CSA - 13固定在MNP上时保留杀菌活性，而当CSA - 13共价连接到纳米颗粒上时生物相容性增加。
