The metastatic spread of cancer cells from the primary tumor to distant sites leads to a poor prognosis in cancers originating from multiple organs. Increasing evidence has linked selectin-based adhesion between circulating tumor cells (CTCs) and endothelial cells of the microvasculature to metastatic dissemination, in a manner similar to leukocyte adhesion during inflammation. Functionalized biomaterial surfaces hold promise as a diagnostic tool to separate CTCs and potentially treat metastasis, utilizing antibody and selectin-mediated interactions for cell capture under flow. However, capture at high purity levels is challenged by the fact that CTCs and leukocytes both possess selectin ligands. Here, a straightforward technique to functionalize and alter the charge of naturally occurring halloysite nanotubes using surfactants is reported to induce robust, differential adhesion of tumor cells and blood cells to nanotube-coated surfaces under flow. Negatively charged sodium dodecanoate-functionalized nanotubes simultaneously enhanced tumor cell capture while negating leukocyte adhesion, both in the presence and absence of adhesion proteins, and can be utilized to isolate circulating tumor cells regardless of biomarker expression. Conversely, diminishing nanotube charge via functionalization with decyltrimethylammonium bromide both abolished tumor cell capture while promoting leukocyte adhesion.

Hematogenous metastasis, the process of cancer cell migration from a primary to distal location via the bloodstream, typically leads to a poor patient prognosis. Selectin proteins hold promise in delivering drug-containing nanocarriers to circulating tumor cells (CTCs) in the bloodstream, due to their rapid, force-dependent binding kinetics. However, it is challenging to deliver such nanocarriers while avoiding toxic effects on healthy blood cells, as many possess ligands that adhesively interact with selectins. Herein, we describe a nanostructured surface to capture flowing cancer cells, while preventing human neutrophil adhesion. Microtube surfaces with immobilized halloysite nanotubes (HNTs) and E-selectin functionalized liposomal doxorubicin (ESPEG L-DXR) significantly increased the number of breast adenocarcinoma MCF7 cells captured from flow, yet also significantly reduced the number of captured neutrophils. Neutrophils firmly adhered and projected pseudopods on surfaces coated only with liposomes, while neutrophils adherent to HNT-liposome surfaces maintained a round morphology. Perfusion of both MCF7 cells and neutrophils resulted in primarily cancer cell adhesion to the HNT-liposome surface, and induced significant cancer cell death. This work demonstrates that nanostructured surfaces consisting of HNTs and ES-PEG L-DXR can increase CTC recruitment for chemotherapeutic delivery, while also preventing healthy cell adhesion and uptake of therapeutic intended for CTCs.

The metastatic spread of tumor cells from the primary site to anatomically distant organs leads to a poor patient prognosis. Increasing evidence has linked adhesive interactions between circulating tumor cells (CTCs) and endothelial cells to metastatic dissemination. Microscale biomimetic flow devices hold promise as a diagnostic tool to isolate CTCs and develop metastatic therapies, utilizing E-selectin (ES) to trigger the initial rolling adhesion of tumor cells under flow. To trigger firm adhesion and capture under flow, such devices also typically require antibodies against biomarkers thought to be expressed on CTCs. This approach is challenged by the fact that CTCs are now known to exhibit heterogeneous expression of conventional biomarkers. Here, we describe surfactant-nanotube complexes to enhance ES-mediated capture and isolation of tumor cells without the use of capture antibodies. While the majority of tumor cells exhibited weaker rolling adhesion on halloysite nanotubes (HNT) coated with ES, HNT functionalization with the sodium dodecanoate (NaL) surfactant induced a switch to firm cellular adhesion under flow. Conversely, surfactant-nanotube complexes significantly reduced the number of primary human leukocytes captured via ES-mediated adhesion under flow. The switch in tumor cell adhesion was exploited to capture and isolate tumor cells in the absence of EpCAM antibodies, commonly utilized as the gold standard for CTC isolation. Additionally, HNT-NaL complexes were shown to capture tumor cells with low to negligible EpCAM expression, that are not efficiently captured using conventional approaches.

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Este artículo presenta los resultados del análisis de las pruebas de absorción de humedad y capacidad de carga que se realizaron a blocks tradicionales de concreto para mampostería y blocks de plástico. Las pruebas se realizaron en el Tecnológico Nacional de México plantel Instituto Tecnológico de Tepic, por docentes y alumnos de la carrera de Ingeniería Civil. Esta información da continuidad a los proyectos de investigación que se han realizado en esta área en los últimos 2 años y que complementan dicha información. El objetivo final es validar si se pueden usar blocks hechos con agregado de plástico reciclado para disminuir el efecto de los desechos plásticos en el medio ambiente y poder establecer una posibilidad de su reutilización.