Instrument-Dependent Factors Affecting the Precision in the Atomic Force Microscopy Stiffness Measurement of Nanoscale Liposomes.

Instrument-Dependent Factors Affecting the Precision in the Atomic Force Microscopy Stiffness Measurement of Nanoscale Liposomes. Chem Pharm Bull (Tokyo). 2020;68(5):473-478 Authors: Takechi-Haraya Y, Goda Y, Izutsu K, Sakai-Kato K Abstract The mechanical strength (stiffness) of liposomes affects their cellular uptake efficiency and drug release in drug delivery processes. We recently developed a tip shape evaluation method for improving the precision of liposome stiffness measurement by quantitative imaging (QI)-mode atomic force microscopy (AFM). The present study applied our method to the widely-used AFM instruments equipped for intermittent contact (IC)-mode force curve measurements, and examined instrument-dependent factors that affect the liposome stiffness measurements. We demonstrated that the evaluation of the tip shape for cantilever selection can be applicable to the IC mode as well as the QI mode. With the cantilever selection, the improved precision of the liposome stiffness was obtained when the stiffness of each liposome was determined from the slope in the force-deformation curve by the IC-mode force curve measurement. Further, the stiffness values were found to be similar to that measured by QI-mode measurements. These results indicate that our developed method can be widely used via IC-mode force curve measurements as well as via QI mode. It was also revealed that spatial drift of the cantilever position was instrum...
Source: Chemical and Pharmaceutical Bulletin - Category: Drugs & Pharmacology Authors: Tags: Chem Pharm Bull (Tokyo) Source Type: research