Evaluating The Nano-drug Efficacy By Analyzing Cell Mechanics With Atomic Force Microscopy

Nano drugs has the dual advantages of targeted drug delivery and controlled drug release,and has become a new research hotspot of anti-tumor drugs.Nano drugs need to be evaluated in terms of release rate,cytotoxicity,and duration of action.Because many evaluation methods are relatively complicated at present,this paper uses a relatively simple method to study the mechanical properties of cells using the nano-indentation technology of atomic force microscopy（AFM）to evaluate the efficacy of nano drugs.The main contents are as follows:1.The feasibility of AFM-based nanoindentation analysis of drug efficacy was tested on cells treated with doxorubicin（DOX）.The Young’s modulus of cervical cancer（HeLa）cells without drugs was 3480.22±398.36 Pa.After incubating HeLa cells with 3 mM DOX for 1 h,the Young’s modulus decreased to 1376.52±71.99 Pa.After incubating normal HeLa cells with 0.5 mM DOX for 4 h,the Young’s modulus decreased to 1061.14±71.88Pa.The feasibility of evaluating the efficacy of drugs based on AFM nanoindentation technology was confirmed.2.Further testing the efficacy of liposome nanomedicine,the Young’s modulus of HeLa cells was 661.44±66.27 Pa after treatment with doxorubicin liposomes(L_DOX)for 3 h（0.25mM）.After treatment with camptothecin（CPT）liposomes(L_CPT)for 3 h（0.25 mM）,the Young’s modulus of HeLa cells was 654.42±65.61 Pa.At the same time,when the two drugs were mixed and loaded with liposomes,a synergistic effect was found in multidrug liposomes mixed with DOX:CPT=4:1(L_4:1)and DOX:CPT=1:4(L_1:4).After treatment with L_4:1:1 for 3 h（0.25 mM）,the Young’s modulus of HeLa cells was 606.61±65.88 Pa.It further confirmed the feasibility of measuring the efficacy of drugs based on AFM nanoindentation technology.3.The viscoelasticity of cells was measured by AFM mechanical detection technology to evaluate the efficacy of nano-medicine.The viscoelasticity of HeLa cells increased from25.11±1.43%without drug to 43.99±1.39%（3 h,0.25 mM）.This paper will provide an intuitive and effective method for the study of drug efficacy.