Dynamic Micropatterning of Cells on Nanostructured Surfaces Using a Cell-friendly Photoresist.

Cellular dynamics under complex topographical microenvironments are important for many biological processes in development and diseases, but systematic investigation has been limited due to the lack of technology. Herein, we developed a new dynamic cell patterning method based on a cell-friendly photoresist polymer that allows in situ control of cell dynamics on nanostructured surfaces. Using this method, we quantitatively compared the spreading dynamics of cells on nanostructured surfaces to those on flat surfaces.

Cholesterol selectively activates canonical Wnt signalling over non-canonical Wnt signalling.

Wnt proteins control diverse biological processes through β-catenin-dependent canonical signalling and β-catenin-independent non-canonical signalling. The mechanisms by which these signalling pathways are differentially triggered and controlled are not fully understood. Dishevelled (Dvl) is a scaffold protein that serves as the branch point of these pathways.

A comparative study on collagen type I and hyaluronic acid dependent cell behavior for osteochondral tissue bioprinting.

Bioprinting is a promising technique for engineering composite tissues, such as osteochondral tissues. In this study, as a first step toward bioprinting-based osteochondral tissue regeneration, we systematically examined the behavior of chondrocytes and osteoblasts to hyaluronic acid (HA) and type I collagen (Col-1) hydrogels. First, we demonstrated that cells on hydrogels that were comprised of major native tissue extracellular matrix (ECM) components (i.

T cells sense biophysical cues using lamellipodia and filopodia to optimize intraluminal path finding.

Intraluminal crawling is considered to be important for extravasation of leukocytes in blood vessels, but biochemical/biophysical cues guiding the crawling of leukocytes have not been clearly understood. Here we provide evidence that T cells sense the topography of luminal surfaces and the nuclei of endothelial cells (ECs) using lamellipodia and filopodia, respectively, to optimize path finding during intraluminal crawling. Well-aligned EC layers or replicas of EC layers, which exhibit topography similar to that of EC layers, were fabricated, and flow was applied either parallel or perpendicular to the orientation of EC alignment.

Photopatterning with a printed transparency mask and a protein-friendly photoresist.

Microscope projection photolithography (MPP) based on a protein-friendly photoresist is a versatile tool for the fabrication of protein- and cell-micropatterned surfaces. Photomasks containing various features can be economically produced by printing features on transparency films. Features in photomasks are projected by the objective lens of a microscope, resulting in a significant reduction of the feature size to as small as ~1 μm, close to the practical limit of light-based microfabrication.

Negative role of inducible PD-1 on survival of activated dendritic cells.

PD-1 is a well-established negative regulator of T cell responses by inhibiting proliferation and cytokine production of T cells via interaction with its ligands, B7-H1 (PD-L1) and B7-DC (PD-L2), expressed on non-T cells. Recently, PD-1 was found to be expressed in innate cells, including activated DCs, and plays roles in suppressing production of inflammatory cytokines. In this study, we demonstrate that PD-1 KO DCs exhibited prolonged longevity compared with WT DCs in the dLNs after transfer of DCs into hind footpads.

Dynamic modulation of small-sized multicellular clusters using a cell-friendly photoresist.

Dynamics of small-sized multicellular clusters is important for many biological processes including embryonic development and cancer metastasis. Previous methods to fabricate multicellular clusters depended on stochastic adhesion and proliferation of cells on defined areas of cell-adhering islands. This made precise control over the number of cells within multicellular clusters impossible.

High-throughput quantitative imaging of cell spreading dynamics by multi-step microscopy projection photolithography based on a cell-friendly photoresist.

A new method for the high-throughput study of cell spreading dynamics is devised by multi-step microscopy projection photolithography based on a cell-friendly photoresist. By releasing a large number of rounded cells in single cell arrays and monitoring their spreading dynamics by interference reflection microscopy, a large number of cell spreading data can be acquired by a single experiment.

Microfabricated platforms to modulate and monitor T cell synapse assembly.

Immunological synapse (IS) is a complex supramolecular structure formed at the interface between T cells and antigen presenting cells (APCs) during T cell antigen recognition. Microfabricated platforms have made great contributions to our understanding of the assembly dynamics and functional roles of the T cell synapses over the last decade. Here, we review three different types of microfabricated platforms developed to modulate and monitor the T cell synapse assembly.

Nanotopography-guided migration of T cells.

T cells navigate a wide variety of tissues and organs for immune surveillance and effector functions. Although nanoscale topographical structures of extracellular matrices and stromal/endothelial cell surfaces in local tissues may guide the migration of T cells, there has been little opportunity to study how nanoscale topographical features affect T cell migration. In this study, we systematically investigated mechanisms of nanotopography-guided migration of T cells using nanoscale ridge/groove surfaces.

Multiscale fabrication of multiple proteins and topographical structures by combining capillary force lithography and microscope projection photolithography.

We present new methods that enable the fabrication of multiscale, multicomponent protein-patterned surfaces and multiscale topologically structured surfaces by exploiting the merits of two well-established techniques: capillary force lithography (CFL) and microscope projection photolithography (MPP) based on a protein-friendly photoresist. We further demonstrate that, when hierarchically organized micro- and nanostructures were used as a cell culture platform, human colon cancer cells (cell line SW480) preferentially adhere and migrate onto the area with nanoscale topography over the one with microscale topography. These methods will provide many exciting opportunities for the study of cellular responses to multiscale physicochemical cues.

Addressable micropatterning of multiple proteins and cells by microscope projection photolithography based on a protein friendly photoresist.

We report a new method for the micropatterning of multiple proteins and cells with micrometer-scale precision. Microscope projection photolithography based on a new protein-friendly photoresist, poly(2,2-dimethoxy nitrobenzyl methacrylate-r-methyl methacrylate-r-poly(ethylene glycol) methacrylate) (PDMP), was used for the fabrication of multicomponent protein/cell arrays. Microscope projection lithography allows precise registration between multiple patterns as well as facile fabrication of microscale features.

Discrete hypoechoic ring in hepatic cavernous hemangioma resembling a malignant tumor: correlation with histologic features.

Differential diagnoses of hepatic nodules include hepatocellular carcinoma, focal nodular hyperplasia, hepatic adenoma, regenerative nodule, focal fatty changes, and hemangioma. However, differentiation of these nodules can often be difficult. Hemangiomas are frequently encountered during ultrasonogram incidentally and can be diagnosed easily because they have an almost distinctive sonographic appearance: a homogeneous hyperechogenicity and discrete posterior acoustic enhancement.

Radiofrequency ablation of renal VX2 tumors with and without renal artery occlusion in a rabbit model: feasibility, therapeutic efficacy, and safety.

The purpose of this study was to determine the therapeutic efficacy of radiofrequency ablation for treating renal VX2 tumors with and without renal artery occlusion in a rabbit model. Twenty-four New Zealand White rabbits were percutaneously implanted with renal VX2 tumors. Fifteen days after implantation, both kidneys were surgically exposed, and radiofrequency ablation was conducted.

[Prognostic factors for survival in patients with hepatocellular carcinoma after radiofrequency ablation].

Background/aims: Currently there is no consensus on which staging system is the best in predicting the survival of patients with hepatocellular carcinoma (HCC). The aim of this study was to identify independent factors to predict survival and to compare 4 available prognostic staging systems in patients with early HCC after radiofrequency ablation.

Methods: We retrospectively studied 100 Korean patients with early HCC.

Benign submucosal lesions of the stomach and duodenum: imaging characteristics with endoscopic and pathologic correlation.

Benign submucosal lesions of the stomach and duodenum are occasionally encountered during endoscopy. But endoscopy has its limitations in the diagnosis and differentiation of these lesions, because submucosal lesions are often difficult to visualize at endoscopy due to minimal change of the overlying mucosa. Furthermore, endoscopic biopsy may not always yield adequate tissue for diagnosis due to the submucosal location of the lesions.

[Evaluation of predictive value of Okuda, TNM, CLIP and JIS staging systems for hepatocellular carcinoma patients].

Background/aims: The aims of this study were to validate the prognostic value of the JIS score for HCC and to compare discriminatory ability and predictive power with other staging systems such as Okuda, TNM and CLIP.

Methods: We analyzed the clinical records of 210 patients who were diagnosed as HCC from 2000 to 2002. Univariate and multivariate survival analyses were done to find out factors to affect survival.