The clinical potential of circulating tumor cells; the need to incorporate a modern "immunological cocktail" in the assay

Tannic Acid (TA)-Functionalized Magnetic Nanoparticles for EpCAM-Independent Circulating Tumor Cell (CTC) Isolation from Patients with Different Cancers

The majority of current methods of isolating circulating tumor cells (CTCs) rely on a biomarker. However, the isolation efficiency may be compromised due to the heterogeneity of CTCs. In this work, a simple and broad-spectrum method is established to efficiently isolate the heterogeneous CTCs from patient blood samples using tannic acid (TA)-functionalized magnetic nanoparticles (MNPs). The TA-functionalized MNPs (MNPs-TA) inhibit the nonspecific adhesion of peripheral blood mononuclear cell (PBMC) and enhance cancer cell capture, resulting from the unique interaction between TA and glycocalyx on cancer cells. The MNPs-TA was demonstrated to effectively capture seven kinds of cancer cells (HeLa, PC-3, T24, MAD-MB-231, MCF-7, HT1080, A549) from artificial samples (62.3-93.7%). Moreover, this epithelial cell adhesion molecule (EpCAM)-independent CTC isolation method was also tested using clinical blood samples from patients with different cancers (21 patients), which may provide a universal tool to detect CTCs in the clinic.

Development of a Multifunctional Nanobiointerface Based on Self-Assembled Fusion-Protein rSbpA/ZZ for Blood Cell Enrichment and Phenotyping

We present a multifunctional nanobiointerface for blood cell capture and phenotyping applications that features both excellent antifouling properties and high antibody activity. Multifunctionality is accomplished by modifying polymeric materials using self-assembled S-layer fusion-protein rSbpA/ZZ to immobilize high density antibodies at the two protein A binding sites of the rSbpA/ZZ nanolattice structure. Controlled orientation and alignment of the antibodies reduced antibody consumption 100-fold and increased cell capture efficiency 4-fold over standard methodologies. Cell analysis in complex samples was made possible by the remarkable antifouling properties of the rSbpA domain, while at the same time reducing unspecific binding and forgoing tedious blocking procedures. An automated microfluidic in situ cell analysis platform for isolation and phenotyping of primary peripheral blood mononuclear cells was developed as practical application. Results obtained using our automated microfluidic cell analysis platform showed that the multifunctional nanobiointerface can discriminate among T helper and cytotoxic T cells, and thymocytes. Additionally, on-chip cell capture under flow conditions using a high affinity CD 3 selective nanobiointerface preferentially isolated cells with strong surface marker expression. This means that our dynamic microfluidic cell purification method allows the enrichment of 773 CD 8 positive cytotoxic T cells out of a total blood cell population of 7728 PBMCs, which is an increase in cell enrichment of 8-fold with a purity of 85%.

Dynamic changes in numbers and properties of circulating tumor cells and their potential applications

Circulating tumor cells (CTCs) can be detected in the blood of different types of early or advanced cancer using immunology-based assays or nucleic acid methods. The detection and quantification of CTCs has significant clinical utility in the prognosis of metastatic breast, prostate, and colorectal cancers. CTCs are a heterogeneous population of cells and often different from those of their respective primary tumor. Understanding the biology of CTCs may provide useful predictive information for the selection of the most appropriate treatment. Therefore, CTC detection and characterization could become a valuable tool to refine prognosis and serve as a "real-time biopsy" and has the potential to guide precision cancer therapies, monitor cancer treatment, and investigate the process of metastasis.

Carboxybetaine methacrylate-modified nylon surface for circulating tumor cell capture

Conventional in vitro circulating tumor cell (CTC) detection methods are always limited by blood sample volume because of the requirement of a large amount of blood. The aim of this study was to overcome the limitation by designing and making an in vivo CTC capture device. In this study, we designed and prepared a kind of proper material to serve the purpose of intervention. A method employing 3-aminopropyltriethoxysilane (γ-APS) as the coupling reagent to graft carboxybetaine methacrylate (CBMA) and to immobilize an anti-epithelial cell adhesion molecular (EpCAM) antibody on Nylon was developed. The results of X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy proved the successful graft of γ-APS and CBMA to Nylon. Furthermore, the predicted improvement in the biocompatibilities of our modified Nylon was confirmed by water contact angle measurement, bovine serum albumin adhesion, platelet adhesion, plasma recalcification time determination, and cytotoxicity tests. The tumor cells adhesion experiment revealed that Nylon with the antibody immobilized on it had an affinity for EpCAM positive tumor cells higher than that of pristine Nylon. Additionally, the capture ability of the CTCs was demonstrated in a nude mouse tumor model using the interventional device made of the modified Nylon wire. The positive results suggest that CBMA-grafted and anti-EpCAM antibody-immobilized Nylon is a promising new material for in vivo CTC capture devices.