Zhaobo He

Capture and Release of Cancer Cells Based on Sacrificeable Transparent MnO2 Nanospheres Thin Film

A CTCs detection assay using transparent MnO2 nanospheres thin films to capture and release of CTCs is reported. The enhanced local topography interaction between extracellular matrix scaffolds and the antibody-coated substrate leads to improved capture efficiency. CTCs captured from artificial blood sample can be cultured and released, represent a new functional material capable of CTCs isolation and culture for subsequent studies.

Capture and release of cancer cells using electrospun etchable MnO2 nanofibers integrated in microchannels

This paper introduces a cancer cell capture/release microchip based on the self-sacrificed MnO2 nanofibers. Through electrospinning, lift-off and soft-lithography procedures, MnO2 nanofibers are tactfully fabricated in microchannels to implement enrichment and release of cancer cells in liquid samples. The MnO2 nanofiber net which mimics the extra cellular matrix can lead to high capture ability with the help of a cancer cell-specific antibody bio-conjugation. Subsequently, an effective and friendly release method is carried out by using low concentration of oxalic acid to dissolve the MnO2 nanofiber substrate while keeping high viability of those released cancer cells at the same time. It is conceivable that our microchip may have potentials in realizing biomedical analysis of circulating tumor cells for biological and clinical researches in oncology.

Effective cancer targeting and imaging using macrophage membrane‐camouflaged upconversion nanoparticles

Upconversion nanoparticles (UCNPs), with fascinating optical and chemical features, are a promising new generation of fluorescent probes. Although UCNPs have been widely used in diagnosis and therapy, there is an unmet need for a simple and effective surface engineering method that can produce cancer-targeting UCNPs. Here, we show that by coating particles with macrophage membranes, it becomes possible to utilize the adhesion between macrophages and cancer cells for effective cancer targeting. Natural macrophage membranes along with their associated membrane proteins were reconstructed into vesicles and then coated onto synthetic UCNPs. The resulting macrophage membrane-camouflaged particles (MM-UCNPs) exhibited effective cancer targeting capability inherited from the source cells and were further used for enhanced in vivo cancer imaging. Finally, the blood biochemistry, hematology testing and histology analysis results suggested a good in vivo biocompatibility of MM-UCNPs. The combination of synthetic nanoparticles with biomimetic cell membranes embodies a novel design strategy toward developing biocompatible nanoprobes for potential clinical applications.

Autofluorescent gelatin nanoparticles as imaging probes to monitor matrix metalloproteinase metabolism of cancer cells.

In this paper, autofluorescent gelatin nanoparticles were synthesized as matrix metalloproteinase (MMP) responsive probes for cancer cell imaging. A modified two-step desolvation method was employed to generate these nanoparticles whose size was controllable and had stable autofluorescence. As glutaraldehyde was introduced as the crosslinking agent, the generation of Schiff base (CN) and double carbon bond (CC) between glutaraldehyde and gelatin endowed these gelatin nanoparticles distinct autofluorescence. Considering MMPs were usually overexpressed on the surface of cancer cells and they had degradation ability toward gelatin, we utilized these nanoparticles as imaging probes to responsively monitor the MMP metabolism of cancer cells according to the luminance change. As fluorescent probes, these nanoparticles had facile synthesis procedure and good biocompatibility, and provided a smart strategy to monitor cancer cell behaviors.

Efficient Purification and Release of Circulating Tumor Cells by Synergistic Effect of Biomarker and SiO2@Gel‐Microbead‐Based Size Difference Amplification

Microfluidics-based circulating tumor cell (CTC) isolation is achieved by using gelatin-coated silica microbeads conjugated to CTC-specific antibodies. Bead-binding selectively enlarges target cell size, providing efficient high-purity capture. CTCs captured can be further released non-invasively. This stratagem enables high-performance CTC isolation for subsequent studies.

Transparent, biocompatible nanostructured surfaces for cancer cell capture and culture

Circulating tumor cells (CTCs) in the blood which have detached from both the primary tumor and any metastases may be considered as a “liquid biopsy” and are expected to replace tumor biopsies in the monitoring of treatment response and determining patient prognosis. Here, we introduce a facile and efficient CTC detection material made of hydroxyapatite/chitosan (HA/CTS), which is beneficial because of its transparency and excellent biological compatibility. Atomic force microscopy images show that the roughness of the HA/CTS nanofilm (HA/CTSNF) substrates can be controlled by changing the HA:CTS ratio. Enhanced local topographic interactions between nano-components on cancer cell membranes, and the antibody coated nanostructured substrate lead to improved CTC capture and separation. This remarkable nanostructured substrate has the potential for CTC culture in situ and merits further analysis. CTCs captured from artificial blood samples were observed in culture on HA/CTSNF substrates over a period of 14 days by using conventional staining methods (hematoxylin eosin and Wright’s stain). We conclude that these substrates are multifunctional materials capable of isolating and culturing CTCs for subsequent studies.

Capture and Identification of Heterogeneous Circulating Tumor Cells Using Transparent Nanomaterials and Quantum Dots-Based Multiplexed Imaging

Background: Capture and identification of circulating tumor cells (CTCs) in the blood system can help guide therapy and predict the prognosis of cancer patients. However, simultaneous capture and identification of CTCs with both epithelial and mesenchymal phenotypes remains a formidable technical challenge for cancer research. This study aimed at developing a system to efficiently capture and identify these CTCs with heterogeneous phenotypes using transparent nanomaterials and quantum dots (QDs)-based multiplexed imaging. Methods: Hydroxyapatite-chitosan (HA-CTS) nanofilm-coated substrates were modified based on our previous work to increase the capture efficiency of cancer cell lines by extending baking and incubating time. QDs-based imaging was applied to detect cytokeratin, epithelial cell adhesion molecule (EpCAM), and vimentin of cancer cells to demonstrate the feasibility of multiplexed imaging. And QDs-based multiplexed imaging of CD45, cytokeratin and vimentin was applied to detect CTCs from different cancer patients that were captured using HA-CTS nanofilm substrates. Results: Comparisons of the capture efficiencies of cancer cells at different baking time of film formation and incubating time of cell capture revealed the optimal baking and incubating time. Optimal time was chosen to develop a modified CTCs capture system that could capture EpCAM-positive cancer cells at an efficiency > 80%, and EpCAM-negative cancer cells at an efficiency > 50%. QDs-based imaging exhibited comparable detection ability but higher photostability compared to organic dyes imaging in staining cells. In addition, QDs-based multiplexed imaging also showed the molecular profiles of cancer cell lines with different phenotypes well. The integrated CTCs capture and identification system successfully captured and imaged CTCs with different sub-phenotypes in blood samples from cancer patients. Conclusion: This study demonstrated a reliable capture and detection system for heterogeneous CTCs that combined enrichment equipment based on HA-CTS nanofilm substrates with QDs-based multiplexed imaging.

Fetal nucleated red blood cell analysis for non-invasive prenatal diagnostics using a nanostructure microchip

Cell-free DNA has been widely used in non-invasive prenatal diagnostics (NIPD) nowadays. Compared to these incomplete and multi-source DNA fragments, fetal nucleated red blood cells (fNRBCs), once as an aided biomarker to monitor potential fetal pathological conditions, have re-attracted research interest in NIPD because of their definite fetal source and the total genetic information contained in the nuclei. Isolating these fetal cells from maternal peripheral blood and subsequent cell-based bio-analysis make maximal genetic diagnosis possible, while causing minimal harm to the fetus or its mother. In this paper, an affinity microchip is reported which uses hydroxyapatite/chitosan nanoparticles as well as immuno-agent anti-CD147 to effectively isolate fNRBCs from maternal peripheral blood, and on-chip biomedical analysis was demonstrated as a proof of concept for NIPD based on fNRBCs. Tens of fNRBCs can be isolated from 1 mL of peripheral blood (almost 25 mL-1 in average) from normal pregnant women (from the 10th to 30th gestational week). The diagnostic application of fNRBCs for fetal chromosome disorders (Trisomy 13 and 21) was also demonstrated. Our method offers effective isolation and accurate analysis of fNRBCs to implement comprehensive NIPD and to enhance insights into fetal cell development.

Gelatin Nanoparticle-Coated Silicon Beads for Density-Selective Capture and Release of Heterogeneous Circulating Tumor Cells with High Purity

Background: Circulating tumor cells (CTCs) are a burgeoning topic in cancer biomarker discovery research with minimal invasive blood draws. CTCs can be used as potential biomarkers for disease prognosis, early cancer diagnosis and pharmacodynamics. However, the extremely low abundance of CTCs limits their clinical utility because of technical challenges such as the isolation and subsequent detailed molecular and functional characterization of rare CTCs from patient blood samples. Methods: In this study, we present a novel density gradient centrifugation method employing biodegradable gelatin nanoparticles coated on silicon beads for the isolation, release, and downstream analysis of CTCs from colorectal and breast cancer patients. Results: Using clinical patient/spiked samples, we demonstrate that this method has significant CTC-capture efficiency (>80%) and purity (>85%), high CTC release efficiency (94%) and viability (92.5%). We also demonstrate the unparalleled robustness of our method in downstream CTC analyses such as the detection of PIK3CA mutations. Conclusion: The efficiency and versatility of the multifunctional density microbeads approach provides new opportunities for personalized cancer diagnostics and treatments.

Non-invasive Prenatal Diagnosis of Chromosomal Aneuploidies and Microdeletion Syndrome Using Fetal Nucleated Red Blood Cells Isolated by Nanostructure Microchips

Detection of detached fetal nucleated red blood cells (fNRBCs) in the maternal peripheral blood may serve as a prospective testing method competing with the cell-free DNA, in non-invasive prenatal testing (NIPT). Methods: Herein, we introduce a facile and effective lab-on-a-chip method of fNRBCs detection using a capture-releasing material that is composed of biotin-doped polypyrrole nanoparticles. To enhance local topographic interactions between the nano-components and fNRBC, a specific antibody, CD147, coated on the nanostructured substrate led to the isolation of fNRBCs from maternal peripheral blood. Subsequently, an electrical system was employed to release the captured cells using 0.8 V for 15 s. The diagnostic application of fNRBCs for fetal chromosomal disorders (Trisomy 13/21/18/X syndrome, microdeletion syndrome) was demonstrated. Results: Cells captured by nanostructured microchips were identified as fNRBCs. Twelve cases of chromosomal aneuploidies and one case of 18q21 microdeletion syndrome were diagnosed using the fNRBCs released from the microchips. Conclusion: Our method offers effective and accurate analysis of fNRBCs for comprehensive NIPT to monitor fetal cell development.