Using Atomic Force Microscopy to Predict Tumor Specificity of ICAM1 Antibody-Directed Nanomedicines

Abstract

Atomic force microscopy (AFM) is a powerful tool to detect in vitro antibody-antigen interactions. To date, however, AFM-measured antibody-antigen interactions have yet to be exploited to predict in vivo tumor specificity of antibody-directed nanomedicines. In this study, we have utilized AFM to directly measure the biomechanical interaction between live triple negative breast cancer (TNBC) cells and an antibody against ICAM1, a recently identified TNBC target. For the first time, we provide proof-of-principle evidence that in vitro TNBC cell-ICAM1 antibody binding force measured by AFM on live cells more precisely correlates with in vivo tumor accumulation and therapeutic efficacy of ICAM1 antibody-directed liposomes than ICAM1 gene and surface protein overexpression levels. These studies demonstrate that live cell-antibody binding force measurements may be used as a novel in vitro metric for predicting the in vivo tumor recognition of antibody-directed nanomedicines.

Therapeutic genome editing of triple-negative breast tumors using a noncationic and deformable nanolipogel

“…Three CRISPR plasmids targeted to different DNA sequences of Lcn2 were used in combination to maximize the genome editing efficiency. ICAM1, a recently discovered TNBC nanotherapeutic target (15,16), was utilized; the ICAM1 antibody was covalently conjugated on the surface of tNLGs at a density of ∼3,000 antibodies per μm 2 . Three other NLG formulations were also constructed as controls and tested together with commercially available cationic CRISPR transfection reagents (Ultracruz and Lipofectamine 2000) ( Table 1).…”

“…Unlike the hollow bilayer structure of conventional liposomes, the presence of a dense and deformable hydrogel core in tNLGs was apparent. The elastic modulus of the tNLG structure was previously determined to be 1.3 MPa, using atomic force microcopy (16), significantly softer and more deformable than conventional solid lipid or polymer nanoparticles with elastic moduli ranging from 0.76 GPa to 1.2 GPa (17,18). The EE of gene delivery via tNLGs was studied using 2 examples: scrambled CRISPR plasmid and scrambled small interfering RNA (siRNA).…”

Quantitative Analysis of Different Cell Entry Routes of Actively Targeted Nanomedicines Using Imaging Flow Cytometry

“…As shown in the schematic illustration (Fig. Its antibody has been demonstrated to guide a variety of nanomedicines to selectively recognize and bind human breast cancer cells in vitro and orthotopic breast tumors in vivo (13,27,28). ICAM1 is a cell membrane receptor for host cell entry of human rhinovirus (26) and has been recently identified as a molecular target for human triple negative breast cancer (27).…”

“…ICAM1 is a cell membrane receptor for host cell entry of human rhinovirus (26) and has been recently identified as a molecular target for human triple negative breast cancer (27). Its antibody has been demonstrated to guide a variety of nanomedicines to selectively recognize and bind human breast cancer cells in vitro and orthotopic breast tumors in vivo (13,27,28). In this study, ICAM1 antibody was selected as the actively targeting ligand covalently conjugated to the surfaces of ICAM1-FusoNLP and ICAM1-EndoNLG.…”

“…Many bioanalytical methods have been used to study cell internalization mechanisms such as confocal fluorescent microscopy and flow cytometry (11)(12)(13); however, there are significant limitations associated with their use for this purpose. For example, sample preparation and operation procedures for confocal fluorescent microscopy are time and labor consuming and are low throughput.…”