Engineering Peptide-Functionalized Biomimetic Nanointerfaces for Synergetic Capture of Circulating Tumor Cells in an EpCAM-Independent Manner

Abstract

Broad-spectrum detection and long-term monitoring of circulating tumor cells (CTCs) remain challenging due to the extreme rarity, heterogeneity, and dynamic nature of CTCs. Herein, a dual-affinity nanostructured platform was developed for capturing different subpopulations of CTCs and monitoring CTCs during treatment. Stepwise assembly of fibrous scaffolds, a ligand-exchangeable spacer, and a lysosomal protein transmembrane 4 β (LAPTM4B)-targeting peptide creates biomimetic, stimuli-responsive, and multivalent-binding nanointerfaces, which enable harvest of CTCs directly from whole blood with high yield, purity, and viability. The stable overexpression of the target LAPTM4B protein in CTCs and the enhanced peptide–protein binding facilitate the capture of rare CTCs in patients at an early stage, detection of both epithelial-positive and nonepithelial CTCs, and tracking of therapeutic responses. The reversible release of CTCs allows downstream molecular analysis and identification of specific liver cancer genes. The consistency of the information with clinical diagnosis presents the prospect of this platform for early diagnosis, metastasis prediction, and prognosis assessment.

Reversible and Highly Ordered Biointerfaces for Efficient Capture and Nondestructive Release of Circulating Tumor Cells

“…Over 98% of HepG2 cells can be readily captured even at a cell count of 10 4 , while <0.43% of white blood cells (WBC, 10 5 to 10 7 ) were retained by Apt-Avi-BCN (Figure B). In the present case, HepG2 cells exhibit a low expression level of EpCAM . Their high capture efficiency by Apt-Avi-BCN clearly indicated that HepG2 binds to TLS11a in an EpCAM-independent manner.…”

“…The clinical utility of the Apt-Avi-BCN interface was further evaluated by analyzing blood samples from 20 HCC patients and 17 healthy volunteers without pretreatment. In each assay, 0.5 mL of whole blood was conducted with the capture/release process followed by a standard three-color immunocytochemistry staining protocol . The cells with CD45-negative and DAPI- and CK-positive staining (DAPI + /CK + /CD45 – ) were recognized as CTCs, whereas those stained positive for CD45 and DAPI but negative for CK (DAPI + /CK – /CD45 + ) were identified as WBCs (Figure A).…”

Nanomaterial-Based Immunocapture Platforms for the Recognition, Isolation, and Detection of Circulating Tumor Cells

“…Immunoaffinity-based platforms usually use molecular probes such as antibodies ( Yin et al, 2018 ; Chen et al, 2019 ; Chu et al, 2019 ; Cui et al, 2019 ), peptides ( Peng et al, 2017 ; Tian et al, 2019 ; Zhong et al, 2021 ), and aptamers ( Chen et al, 2019 ; Dharmasiri et al, 2009 ; Qin et al, 2020 ) for CTC enrichment and isolation. A simple summary of the nanomaterial-based platforms for the immunocapture of CTCs is shown in Figure 1 .…”

“…MNPs, magnetic nanoparticles: reproduced with permission from Tian et al (2019) , Copyright 2019, American Chemical Society. DOPA, 3,4-dihydroxy-L-phenylalanine, a key functional amino acid in mussel adhesive proteins: reproduced with permission from Zhong et al (2021) , Copyright 2021, American Chemical Society. LAPTM4B, lysosomal protein transmembrane 4 β with extraordinarily high expression level in a majority of solid tumors.…”

Self-assembly of Peptide dendrimers and their bio-applications in theranostics

“…Peptides with various functionalities, such as specific targeting, stimuli-responsive, cell penetration and therapeutic potential, can be delicately incorporated in a nano-system to achieve disease diagnosis and therapy [ [2] , [3] , [4] , [5] , [6] ]. Compared to non-peptide compounds, peptide-based nanomaterials possess huge potential applications due to its programmability, biological activity and good biocompatibility [ 7 , 8 ]. In the past decades, the rapid development of peptide dendrimers in the field of bio-applications, especially in cancer diagnostics and therapy, has revolutionized conventional health care and medical technology [ 9 , 10 ].…”