Xueli Liu

Hydrophobic Interaction‐Mediated Capture and Release of Cancer Cells on Thermoresponsive Nanostructured Surfaces

Hydrophobic interaction, one of the universal weak interactions in nature, plays a prominent role in biological processes such as lipid bilayer formation, [ 1 ] protein folding [ 2 ] and protein–protein recognition. [ 3 ] For example, hydrophobic interaction is one of the most important driving forces for the reversible folding of linear polypeptide chains into functional structures. [ 2a ] In contrast to natural live systems which achieve reversible processes through hydrophobic interactions, artifi cial smart systems [ 4 ]

Clam's shell inspired high-energy inorganic coatings with underwater low adhesive superoleophobicity.

Unique underwater low adhesive superoleophobicity is discovered on the pallium-covered region of a short clams shell. This property originates from the shells inorganic composition of CaCO(3) and surface micro/nano-hierarchical structures. The oil-repellent shell provides an innovative strategy to develop novel underwater superoleophobic coatings using inorganic oxides such as copper oxide. This kind of coating is anticipated to be applied on engineering metals to protect aquatic equipment from oil contamination.

Aptamer‐Mediated Efficient Capture and Release of T Lymphocytes on Nanostructured Surfaces

T lymphocytes have fundamental functions in immune responses to many diseases, such as pathogenic infections, malignancies, and autoimmune diseases. Detections of targeted T lymphocytes provide important information in clinical diagnosis. [ 1 ] For example, human immunodefi ciency virus (HIV) depletes CD4 + T lymphocytes in peripheral blood [ 2 ] and other lymphoid tissues. [ 3 ] As a result, the absolute counts of CD4 + T-cells and the ratio of CD4 + /CD8 + T lymphocytes are used as indicators of the onset of autoimmune defi ciency syndrome (AIDS) and as benchmarks for the beginning of antiviral therapy. [ 4 ] Because of the low specifi city and low effi ciency of traditional approaches based on size, density, and fl ow cytometry, cell counts, cell phenotype assessments, and genomic/ mRNA analysis of target cells require the emergence of new effi cient capture and release technologies. Many functional molecules, such as antibodies, [ 5 ] peptides, [ 6 ] and DNA [ 7 ] are immobilized onto various surfaces such as magnetic beads, [ 8 ] 2D microarrays, [ 9 , 10 ] and microfl uidic channels [ 11 , 12 ] for specifi c recognition and capture of targeted cells. The introduction of microfl uidic techniques [ 13 ] has improved the capture effi ciency of targeted cells to a certain extent by optimization of channel dimension, mixing fashion, and fl ow rate. [ 9 , 12 , 14 ] Since capture and release takes place at the interface between cells and substrates, can we realize the effi cient capture and release only by engineering the surface chemistry and topography without the external fl uidic force? Recently, knowledge about cell–nanostructure interactions in biological and artifi cial cell microenvironments has shown that nanometer-scale topography infl uences diverse cell behaviors, including cell adhesion, cell orientation, and cell motility. [ 15 ] In addition, use of size and shape-matched nanometer-scale topography can enhance interactions between the substrate and target cells. [ 16 , 17 ] These fi ndings inspired us to achieve effi cient capture and release of targeted T lymphocytes by directly controlling cell–substrate interactions.

Programmable fractal nanostructured interfaces for specific recognition and electrochemical release of cancer cells.

Topographic recognition of cancer cells is triggered by fractal gold nanostructures (FAuNSs), leading to dramatically enhanced recognition capability and efficient release of cancer cells with little damage. The unique characteristic of FAuNSs is the similar fractal dimension of their surface and that of a cancer cell. The design of fractal nanostructures will open up opportunities for functional design of bio-interfaces for highly efficient recognition and release of disease-related rare cells, which will improve detection in a clinical environment.

An Ion‐Induced Low‐Oil‐Adhesion Organic/Inorganic Hybrid Film for Stable Superoleophobicity in Seawater

Superoleophobicity under seawater: An ion-induced low-oil-adhesion film with underwater superoleophobicity is prepared by a typical layer-by-layer (LBL) method. Under an artificial marine environment with high ion-strength, the prepared polyelectrolytes/AuNPs hybrid film becomes rougher and possesses a higher water ratio, which in turn endows the film with superoleophobicity and low underwater oil adhesion. The as-prepared film shows excellent environmental stability in artificial seawater. This study provides a new strategy for controlling the self-cleaning property and accelerating the development of stable underwater superoleophobic films.

Hierarchical Nanowire Arrays as Three-Dimensional Fractal Nanobiointerfaces for High Efficient Capture of Cancer Cells

A hierarchical assembled ITO nanowire array with both horizontal and vertical nanowire branches was fabricated as a new three-dimensional fractal nanobiointerface for efficient cancer cell capture. Comparing with ITO nanowire array without branches, this fractal nanobiointerface exhibited much higher efficiency (89% vs 67%) and specificity in capturing cancer cells and took shorter time (35 vs 45 min) to reach the maximal capture efficiency. As indicated by the immunofluorescent and ESEM images, this enhancement can be attributed to the improvement of topographical interaction between cells and the substrate. The introduction of horizontal and vertical nanowire branches makes the substrate topographically match better with cell filopodia and provides more binding sites for cell capture. The live/dead cell staining and proliferation experiments confirm that this fractal nanobiointerface displays excellent cyto-compatibility with an over 96% cell viability after capture. These results provide new insights and may open up opportunities in designing and engineering new cell-material interfaces for advanced biomedical applications.

Grooved Organogel Surfaces towards Anisotropic Sliding of Water Droplets

Periodic micro-grooved organogel surfaces can easily realize the anisotropic sliding of water droplets attributing to the formed slippery water/oil/solid interface. Different from the existing anisotropic surfaces, this novel surface provides a versatile candidate for the anisotropic sliding of water droplets and might present a promising way for the easy manipulation of liquid droplets for water collection, liquid-directional transportation, and microfluidics.

A Triggered DNA Hydrogel Cover to Envelop and Release Single Cells

We develop an enzyme-triggered permeable DNA hydrogel cover to envelop and release single cells in microwells. The porous structure of the DNA hydrogel allows nutrients and waste to pass through, leading to a cell viability as high as 98%. The design provides a general method to culture, monitor, and manipulate single cells, and has potential applications in cell patterning and studying cell communication.

Underwater-Transparent Nanodendritic Coatings for Directly Monitoring Cancer Cells

Underwater-transparent nanodendritic coatings are easily fabricated by a three-step template process. After modification with anti-EpCAM, the coatings exhibit the capability for efficiently capturing rare number of cancer cells from whole blood. On the other hand, the unique underwater transparency enables the coatings to directly monitor captured cancer cells by optical imaging.

Hierarchical Biointerfaces Assembled by Leukocyte‐Inspired Particles for Specifically Recognizing Cancer Cells

By mimicking certain biochemical and physical attributes of biological cells, bio-inspired particles have attracted great attention for potential biomedical applications based on cell-like biological functions. Inspired by leukocytes, hierarchical biointerfaces are designed and prepared based on specific molecules-modified leukocyte-inspired particles. These biointerfaces can efficiently recognize cancer cells from whole blood samples through the synergistic effect of molecular recognition and topographical interaction. Compared to flat, mono-micro or nano-biointerfaces, these micro/nano hierarchical biointerfaces are better able to promote specific recognition interactions, resulting in an enhanced cell-capture efficiency. It is anticipated that this study may provide promising guidance to develop new bio-inspired hierarchical biointerfaces for biomedical applications.