Extraction of structurally intact and well-stabilized rice bran oil bodies as natural pre-emulsified O/W emulsions and investigation of their rheological properties and components interaction

The isolated plant oil bodies (OBs) have shown promising applications as natural pre-emulsified O/W emulsions. Rice bran OBs can be used as a new type plant-based resource with superior fatty acids composition and abundant γ-oryzanol. This paper investigated the method of extracting structurally intact and stable rice bran OBs. Due to the adequate steric hindrance and electrostatic repulsion effects, rice bran OBs extracted by NaHCO₃ medium had smaller particle size, better physical stability, and natural structure. The protein profile of NaHCO₃-extracted rice bran OBs showed oleosin-L and oleosin-H, while exogenous proteins in PBS and enzyme-assisted- extracted rice bran OBs could interact with interfacial proteins through hydrophobic forces to aggregate adjacent OBs, further remodeling the OBs interface. It was also found that the small-sized rice bran OBs could adsorb on the interface of the larger-sized rice bran OBs like Pickering stabilizers. Rice bran OBs exhibited pseudoplastic fluids characteristic, but underwent a transition from solid-like to liquid-like behavior depending on the extraction method. The disorder of NaHCO₃-extracted rice bran OBs protein molecules increased their surface hydrophobicity. The random coil structure favored more proteins adsorption at the interface of rice bran OBs extracted by PBS. Enzyme-assisted extraction of rice bran OBs had the highest content of β-sheet structure, which facilitated the stretching and aggregation of protein spatial structure. It was also confirmed the hydrogen bonding and hydrophobic interaction between the triacylglycerol or phospholipid and proteins molecules, and the membrane compositions of rice bran OBs differed between extraction methods.

Simultaneous extraction and determination of alkaloids and organic acids in Uncariae Ramulas Cum Unicis by vortex-assisted matrix solid phase dispersion extraction coupled with UHPLC-MS/MS

A simple and efficient vortex-assisted matrix solid phase dispersion with a ultra-high-performance liquid chromatography-triple quadrupole mass spectrometer (VA-MSPD-UHPLC-MS/MS) was applied for simultaneous extraction and determination of seven alkaloids and three organic acids from Uncariae Ramulas Cum Unicis. The optimal extraction conditions of the target components were obtained by Box-Behnken design (BBD) combined with response surface methodology (RSM). The results of the method validation showed that this analytical method displayed good linearity with a correlation coefficient (r) no lower than 0.9990. The recoveries of ten active ingredients from Uncariae Ramulas Cum Unicis ranged from 95.9% to 103% (RSD ≤ 2.77%). The RSDs of intra-day and inter-day precisions were all below 2.97%. The present method exhibited not only lower solvent and sample usage, but also shorter sample processing and analysis time. Consequently, the developed VA-MSPD-UHPLC-MS/MS method could be successfully and effectively used for the extraction and analysis of ten active components from Uncariae Ramulas Cum Unicis.

Modular snapshot multispectral-panchromatic imager (MSPI) with customized filter arrays

As one of the simplest methods to construct snapshot spectral imagers, multispectral filter array (MSFA) has been applied to commercial miniatured spectral imagers. While most of them have fixed configurations of spectral channels, lacking flexibility and replaceability. Moreover, conventional MSFA only comprises filtering channels but lacks the panchromatic channel which is essential in detecting dim and indistinct objects. Here, we propose a modular assembly method for snapshot imager which can simultaneously acquire the object's multispectral and panchromatic information based on a customized filter array. The multispectral-panchromatic filter array is batch fabricated and integrated with the imaging senor through a modular mode. Five-band spectral images and a broadband intensity image can be efficiently acquired in a single snapshot photographing. The efficacy and accuracy of the imager are experimentally verified in imaging and spectral measurements. Owing to the modular architecture, our proposed assembly method owns the advantages of compactness, simple assembling, rapid replacement, and customized designing, which overcomes the expensiveness and complexity of scientific-level snapshot spectral imaging systems.

Human pharmacokinetics prediction with an in vitro-in vivo correction factor approach and in vitro drug-drug interaction profile of bictegravir, a potent integrase-strand transfer inhibitor component in approved biktarvy® for the treatment of HIV-1 infection

Bictegravir (BIC) is a potent small-molecule integrase strand-transfer inhibitor (INSTI) and a component of Biktarvy^®, a single-tablet combination regimen that is currently approved for the treatment of human immunodeficiency virus type 1 (HIV-1) infection. The in vitro properties, pharmacokinetics (PK), and drug-drug interaction (DDI) profile of BIC were characterised in vitro and in vivo.BIC is a weakly acidic, ionisable, lipophilic, highly plasma protein-bound BCS class 2 molecule, which makes it difficult to predict human PK using standard methods. Its systemic plasma clearance is low, and the volume of distribution is approximately the volume of extracellular water in nonclinical species. BIC metabolism is predominantly mediated by cytochrome P450 enzyme (CYP) 3A and UDP-glucuronosyltransferase 1A1. BIC shows a low potential to perpetrate clinically meaningful DDIs via known drug metabolising enzymes or transporters.The human PK of BIC was predicted using a combination of bioavailability and volume of distribution scaled from nonclinical species and a modified in vitro-in vivo correlation (IVIVC) correction for clearance. Phase 1 studies in healthy subjects largely bore out the prediction and supported the methods used. The approach presented herein could be useful for other drug molecules where standard projections are not sufficiently accurate. .

Large-aperture, widely and linearly tunable, electromagnetically actuated MEMS Fabry-Perot filtering chips for longwave infrared spectral imaging

Longwave infrared spectral imaging (LWIR-SI) has potential in many important civilian and military fields. However, conventional LWIR-SI systems based on traditional dispersion elements always suffer the problems of high cost, large volume and complicated system structure. Micro-electro-mechanical systems Fabry-Perot filtering chips (MEMS-FPFC) give a feasible way for realizing miniaturized, low cost and customizable LWIR-SI systems. The LWIR MEMS-FPFC ever reported can't meet the demands of the next-generation LWIR-SI systems, due to the limitation of small aperture size and nonlinear actuation. In this work, we propose a large-aperture, widely and linearly tunable electromagnetically actuated MEMS-FPFC for LWIR-SI. A multi-field coupling simulation model is built and the wafer-scale bulk-micromachining process is applied to realize the design and fabrication of the proposed MEMS-FPFC. Finally, with the rational structural design and fabrication process, the filtering chip after packaging has an aperture size of 10 mm, which is the largest aperture size of LWIR MEMS-FPFC ever reported. The fabricated electromagnetically actuated MEMS-FPFC can be tuned continuously across the entire LWIR range of 8.39-12.95 µm under ±100 mA driving current with a pretty good linear response of better than 98%. The developed electromagnetically actuated MEMS-FPFC can be directly used for constructing miniaturized LWIR-SI systems, aiming for such applications as military surveillance, gas sensing, and industry monitoring.

A small proportion of X-linked genes contribute to X chromosome upregulation in early embryos via BRD4-mediated transcriptional activation

Females have two X chromosomes and males have only one in most mammals. X chromosome inactivation (XCI) occurs in females to equalize X-dosage between sexes. Besides, mammals also balance the dosage between X chromosomes and autosomes via X chromosome upregulation (XCU) to fine-tune X-linked expression and thus maintain genomic homeostasis. Despite some studies highlighting the importance of XCU in somatic cells, little is known about how XCU is achieved and its developmental role during early embryogenesis. Herein, using mouse preimplantation embryos as the model, we reported that XCU initially occurs upon major zygotic genome activation and co-regulates X-linked expression in cooperation with imprinted XCI during preimplantation development. An in-depth analysis further indicated, unexpectedly, only a small proportion of, but not X chromosome-wide, X-linked genes contribute greatly to XCU. Furthermore, we identified that bromodomain containing 4 (BRD4) plays a key role in the transcription activation of XCU during preimplantation development. BRD4 deficiency or inhibition caused an impaired XCU, thus leading to reduced developmental potential and mitochondrial dysfunctions of blastocysts. Our finding was also supported by the tight association of BRD4 dysregulation and XCU disruption in the pathology of cholangiocarcinoma. Thus, our results not only advanced the current knowledge of X-dosage compensation and provided a mechanism for understanding XCU initiation but also presented an important clue for understanding the developmental and pathological role of XCU.

Stability, Structure, Rheological Properties, and Tribology of Flaxseed Gum Filled with Rice Bran Oil Bodies

In this study, rice bran oil bodies (RBOBs) were filled with varying concentrations of flaxseed gum (FG) to construct an RBOB-FG emulsion-filled gel system. The particle size distribution, zeta potential, physical stability, and microstructure were measured and observed. The molecular interaction of RBOBs and FG was studied by Fourier transform infrared spectroscopy (FTIR). In addition, the rheological and the tribology properties of the RBOB-FG emulsion-filled gels were evaluated. We found that the dispersibility and stability of the RBOB droplets was improved by FG hydrogel, and the electrostatic repulsion of the system was enhanced. FTIR analysis indicated that the hydrogen bonds and intermolecular forces were the major driving forces in the formation of RBOB-FG emulsion-filled gel. An emulsion-filled gel-like structure was formed, which further improved the rheological properties, with increased firmness, storage modulus values, and viscoelasticity, forming thermally stable networks. In the tribological test, with increased FG concentration, the friction coefficient (μ) decreased. The elasticity of RBOB-FG emulsion-filled gels and the ball-bearing effect led to a minimum boundary friction coefficient (μ). These results might contribute to the development of oil-body-based functional ingredients for applications in plant-based foods as fat replacements and delivery systems.

Human and nonclinical disposition of [14C]bictegravir, a potent integrase strand-transfer inhibitor for the treatment of HIV-1 infection

Bictegravir (BIC) is a potent small-molecule integrase strand-transfer inhibitor (INSTI) and a component of Biktarvy®, a single-tablet combination regimen that is currently approved for the treatment of human immunodeficiency virus type 1 (HIV-1) infection. The absorption, metabolism, distribution, and elimination (ADME) characteristics of BIC were determined through in vivo nonclinical and clinical studies (IND 121318).[¹⁴C]BIC was rapidly absorbed orally in mice, rats, monkeys and human. The cumulative dose recovery was high in nonclinical species (>80%) and humans (95.3%), with most of the excreted dose recovered in faeces. Quantifiable radioactivity with declining concentration was observed in rat tissues suggesting reversible binding. Unchanged BIC was the most abundant circulating component in all species along with two notable metabolites M20 (a sulphate conjugate of hydroxylated BIC) and M15 (a glucuronide conjugate of BIC). BIC was primarily eliminated by hepatic metabolism followed by excretion of the biotransformed products into faeces. In vitro drug-drug interaction (DDI) studies with M15 and M20 demonstrated that no clinically relevant interactions were expected.Overall, BIC is a novel and potent INSTI with a favourable resistance, PK, and ADME profile that provides important improvements over other currently available INSTIs for the treatment of HIV-1.

CaCO3 loaded lipid microspheres prepared by the solid-in-oil-in-water emulsions technique with propylene glycol alginate and xanthan gum

Calcium carbonate (CaCO3) is difficult to deliver in food matrices due to its poor solubility. In this work, CaCO3 powders were encapsulated into Solid-in-Oil-in-Water (S/O/W) emulsions to fabricate delivery systems. The impact of the concentrations of propylene glycol alginate and Xanthan gum (PGA-XG) complexes on the physical stability and structural characteristics of S/O/W calcium-lipid emulsions microspheres were studied. The S/O/W calcium-lipid emulsions were characterized by the particle size, zeta potential, physical stability, and apparent viscosity. The S/O/W calcium-lipid emulsion has higher physical stability (including 6-week storage at 4°C), smaller mean particle size (7.60 ± 1.10 μm), and higher negative zeta-potential (45.91 ± 0.97 mV) when the concentration of PGA-XG complexes was 0.8 wt%. Moreover, Confocal laser scanning microscopy (CLSM) images confirmed that the CaCO3 powders were encapsulated in the O phase. Transmission electron microscopy (TEM) showed that S/O/W calcium-lipid emulsion was spherical. The X-ray diffraction (XRD) analysis further confirmed that CaCO3 was loaded in the S/O/W calcium-lipid emulsion as an amorphous state. The formation mechanism of S/O/W calcium-lipid microspheres was studied by Fourier transform infrared spectroscopy (FTIR) and Raman spectrum analysis. This study provided new ideas that accelerate the creation of a novel type of calcium preparation with higher quality utilization.

Abstract 5461: H002: A wide spectrum, highly selective fourth-generation EGFR inhibitor overcoming resistance harboring C797S mutation in NSCLC

BACKGROUND: Resistance to epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) is a major challenge in non-small cell lung cancer (NSCLC) treatment. EGFR activating mutations, such as exon 19 deletions (Del19) and L858R substitution, have been reported in 10-50% of patients with NSCLC. Although these patients respond well to early generations of TKIs, acquired resistance by mechanisms such as T790M mutation compromises their efficacy. Recently, the C797S mutation in combination with Del19 or L858R, and with T790M, has emerged as one of the most common mechanisms underlying on-target resistance to a third generation EGFR TKI, osimertinib. We are developing a fourth-generation EGFR inhibitor, H002, with a wide spectrum and high selectivity to address the growing unmet needs in NSCLC patients harboring C797S mutation.

METHODS: H002’s selectivity was assessed by KINOMEscan against more than 400 human kinases. A panel of 44 kinases was further evaluated to enable early identification of off-target effect. In vitro and in vivo anti-tumor efficacy was determined in drug-resistant mutant cell lines, CDX and PDX models. Single mutants (Del or L858R), double mutants (Del/T790M or L858R/T790M) and triple mutants (Del/T790M/C797S or L858R/T790M/C797S) as well as wild type EGFR were assessed. Drug metabolism and pharmacokinetic (DMPK) properties were further assessed. H002’s safety profile was evaluated in rats and beagle dogs, and by hERG potassium channel assay. Acute toxicity, and repeated dose GLP toxicity studies were also conducted in IND-enabling studies.

RESULTS: High kinase selectivity and very low off-target effects were demonstrated by kinome-wide profiling and safety screening. H002 was highly active against all forementioned single, double or triple EGFR mutants (IC50 < 5 nM), and highly selective against wild type EGFR. H002 also exhibited potent anti-tumor effects in a dose-dependent manner in various CDX and PDX models. Excellent PK properties were observed in rats and beagle dogs with bioavailability over 70%. H002 was shown to cross the blood-brain barrier post i.g. administration in rats. No adverse effects of respiratory, cardiovascular and central nervous system were observed in safety studies. Repeated-dose toxicity studies only showed EGFR-related adverse reactions, such as gastrointestinal and liver toxicity, with high safety margin over 10-folds.

CONCLUSION: H002 has been demonstrated as a promising next generation EGFR inhibitor, with high selectivity, a wide spectrum and potent anti-tumor activity against various EGFR activating mutations, favorable DMPK and safety profiles. It will be further developed as a fourth-generation EGFR inhibitor to overcome drug resistance in NSCLC.

Citation Format: Wei Huang, Lin Zhu, Xiaoe Yan, Xin Huang, Jia Hao, Shan Li, Xiangyu Li, Zhiming Chen, Yunchuan Jia, Haibo Li, Jianming Zhang, Xianming Deng, Caihong Yun. H002: A wide spectrum, highly selective fourth-generation EGFR inhibitor overcoming resistance harboring C797S mutation in NSCLC [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5461.

Manipulation and Mechanical Deformation of Leukemia Cells by High-Frequency Ultrasound Single Beam

Ultrasound single-beam acoustic tweezer system has attracted increasing attention in the field of biomechanics. Cell biomechanics play a pivotal role in leukemia cell functions. To better understand and compare the cell mechanics of the leukemia cells, herein, we fabricated an acoustic tweezer system in-house connected with a 50-MHz high-frequency cylinder ultrasound transducer. Selected leukemia cells (Jurkat, K562, and MV-411 cells) were cultured, trapped, and manipulated by high-frequency ultrasound single beam, which was transmitted from the ultrasound transducer without contacting any cells. The relative deformability of each leukemia cell was measured, characterized, and compared, and the leukemia cell (Jurkat cell) gaining the highest deformability was highlighted. Our results demonstrate that the high-frequency ultrasound single beam can be utilized to manipulate and characterize leukemia cells, which can be applied to study potential mechanisms in the immune system and cell biomechanics in other cell types.

Influence of Carboxymethyl Cellulose on the Stability, Rheological Property, and in-vitro Digestion of Soy Protein Isolate (SPI)-Stabilized Rice Bran Oil Emulsion

In this study, carboxymethyl cellulose (CMC) was added to soybean protein isolate (SPI)-stabilized rice bran oil (RBO) emulsion to improve its physicochemical stability and free fatty acid (FFA) release characteristics. RBO emulsions stabilized by SPI and various contents of CMC were prepared and assessed by measuring zeta potential, particle size, transmission, and microstructure, the rheological properties were analyzed by dynamic shear rheometer. In addition, its chemical stability was characterized by a storage experiment, and the FFA release was explored by a simulated gastrointestinal tract (GIT) model. It showed that the negative charge of the droplets of RBO emulsion was increased with increasing CMC content. The decrease in transmission of SPI-stabilized RBO emulsion with increasing CMC content was due to the droplets not being free to move by the special network interaction and an increase in the viscosity. According to the determination of the reactive substances of lipid hydroperoxide and thiobarbituric acid during 30 days storage at 37°C, the chemical stability of the emulsion added with CMC was enhanced compared with the SPI-stabilized RBO emulsion. In-vitro digestion studies not only evaluated the structural changes of RBO emulsions at different stages, but also found that RBO emulsion with CMC showed a higher level of free fatty acids release in comparison with that without CMC. It indicated that the utilization of CMC can improve the bioavailability of RBO emulsions.

[The research progress of clinical features and pathogenesis of acute acquired concomitant esotropia]

Acute acquired concomitant esotropia (AACE) is a special type of esotropia that occurs suddenly and is accompanied by diplopia. In recent years, the number of patients with this eye disease has increased significantly. With differences in age and refractive status, children and adults have their own characteristics in terms of AACE classification, refractive status, eye position, and binocular visual function. However, the pathogenesis of AACE is still unclear. This article explores the pathogenesis and risk factors of AACE, including refractive error, convergence spasm, extraocular muscle, and visual cortex, that may be involved. The authors recommend that AACE, which is not related to intracranial and systemic diseases, should be classified according to the dominant mechanism of the disease.

Association between Ultra-Processed Food Consumption and Frailty in American Elder People: Evidence from a Cross-Sectional Study

OBJECTIVES

Our study aims to explore the association between ultra-processed foods (UPFs) and frailty in participants with different body mass indexes (BMIs).

DESIGN

A cross-sectional study.

SETTING

Data were collected from the National Health and Nutrition Examination Survey (NHANES) 1999-2000 and 2001-2002.

PARTICIPANTS

We analyzed data from 2,329 participants.

MEASUREMENTS

Dietary data were obtained using 24-h dietary recall method. Frail status was assessed by modified Fried frailty phenotype. The association between the grams, energy, and energy proportion of UPFs and the risk of pre-frailty/frailty was estimated using logistic regression analysis, and odds ratio (OR) with 95% confidence intervals (CIs) were calculated. Participants were categorized into underweight-normal weight (BMI <25 kg/m2), overweight (25 kg/m2 ≤ BMI < 30 kg/m2), and obesity (BMI ≥ 30 kg/m2) groups. The multiplicative interaction between BMIs and UPFs on pre-frailty/frailty was assessed using the logistic regression analysis.

RESULTS

We analyzed data from 2,329 participants, and 2,267 (97.77%) of whom consumed UPFs. There were 1,063 participants in pre-frailty or frailty group and 1,266 participants in non-frailty group. In underweight-normal weight participants, every 100 kcal increase in energy of UPFs intake was associated with increased 0.08 times of pre-frailty or frailty risk (OR: 1.08, 95%CI: 1.00-1.16, P = 0.045), and every 10% increase in energy proportion of UPFs intake was correlated with a 0.02-fold increase in pre-frailty or frailty risk (OR: 1.02, 95%CI: 1.00-1.03, P = 0.018). Similar results were found in overweight participants, with OR of 1.06 (95%CI: 1.01-1.10) and 1.01 (95%CI: 1.00-1.02) for energy and energy proportion, respectively (both P < 0.05). This association was not found in obesity participants.

CONCLUSION

The energy and energy proportion of UPFs intake was positively associated with the frailty risk in underweight-normal weight and overweight people, indicating that population with BMI less than 30 kg/m2 should pay more attention to reasonable diet and balanced source of energy intake.

Sesquiterpenes From Oplopanax elatus Stems and Their Anti-Photoaging Effects by Down-Regulating Matrix Metalloproteinase-1 Expression via Anti-Inflammation

In the process of continuing to investigate ultraviolet b (UVB) irradiation protective constituents from Oplopanax elatus stems, nine new sesquiterpenes, named as eurylosesquiterpenosides A–D (1–4), eurylosesquiterpenols E–I (5–9), and ten known ones (10–19) were gained. Their structures were established by analysis of their NMR spectroscopic data, and electronic circular dichroism calculations were applied to define their absolute configurations. In addition, UVB induced HaCaT cells were used to study their anti-photoaging activities and mechanism. The results consolidated that compounds 7, 11, and 14 could improve the survival rate of HaCaT cells in concentration dependent manner at 10, 25, and 50 μM. Furthermore, western blot assay suggested that all of them could inhibit the expression of matrix metalloproteinase-1 (MMP-1), and increase the level of type I collagen markedly. Compounds 11 and 14 could reduce the phosphorylation of extracellular signal-regulated kinase and p38, respectively. Besides, compounds 7, 11, and 14 could significantly down-regulate the expression of inflammation related protein, such as tumor necrosis factor-α and cyclooxygenase-2, which indicated that they played anti-photoaging activities by reducing MMP-1 expression via down-regulating the production of inflammatory mediators and cytokines in UVB-induced HaCaT cells.

Toward Clinically Applicable 3-Dimensional Tooth Segmentation via Deep Learning

Digital dentistry plays a pivotal role in dental health care. A critical step in many digital dental systems is to accurately delineate individual teeth and the gingiva in the 3-dimension intraoral scanned mesh data. However, previous state-of-the-art methods are either time-consuming or error prone, hence hindering their clinical applicability. This article presents an accurate, efficient, and fully automated deep learning model trained on a data set of 4,000 intraoral scanned data annotated by experienced human experts. On a holdout data set of 200 scans, our model achieves a per-face accuracy, average-area accuracy, and area under the receiver operating characteristic curve of 96.94%, 98.26%, and 0.9991, respectively, significantly outperforming the state-of-the-art baselines. In addition, our model takes only about 24 s to generate segmentation outputs, as opposed to >5 min by the baseline and 15 min by human experts. A clinical performance test of 500 patients with malocclusion and/or abnormal teeth shows that 96.9% of the segmentations are satisfactory for clinical applications, 2.9% automatically trigger alarms for human improvement, and only 0.2% of them need rework. Our research demonstrates the potential for deep learning to improve the efficacy and efficiency of dental treatment and digital dentistry.

Integrating Highly Porous and Flexible Au Hydrogels with Soft-MEMS Technologies for High-Performance Wearable Biosensing

Wearable biosensors for real-time and non-invasive detection of biomarkers are of importance in early diagnosis and treatment of diseases. Herein, a high-performance wearable biosensing platform was proposed by combining a three-dimensional hierarchical porous Au hydrogel-enzyme electrode with high biocompatibility, activity, and flexibility and soft-MEMS technologies with high precision and capability of mass production. Using glucose oxidase as the model enzyme, the glucose sensor exhibits a sensitivity of 10.51 μA mM^-1 cm^-2, a long durability over 15 days, and a good selectivity. Under the mechanical deformation (0 to 90°), it is able to maintain an almost constant performance with a low deviation of <1.84%. With the assistance of a wireless or a Bluetooth module, this wearable sensing platform achieves real-time and non-invasive glucose monitoring on human skins. Similarly, continuous lactic acid monitoring was also realized with lactate oxidase immobilized on the same sensing platform, further verifying the universality of this sensing platform. Therefore, our work holds promise to provide a universal, high-performance wearable biosensing platform for various biomarkers in sweat and reliable diagnostic information for health management.

A Pillar-Free Diffusion Device for Studying Chemotaxis on Supported Lipid Bilayers

Chemotactic cell migration plays a crucial role in physiological and pathophysiological processes. In tissues, cells can migrate not only through extracellular matrix (ECM), but also along stromal cell surfaces via membrane-bound receptor–ligand interactions to fulfill critical functions. However, there remains a lack of models recapitulating chemotactic migration mediated through membrane-bound interactions. Here, using micro-milling, we engineered a multichannel diffusion device that incorporates a chemoattractant gradient and a supported lipid bilayer (SLB) tethered with membrane-bound factors that mimics stromal cell membranes. The chemoattractant channels are separated by hydrogel barriers from SLB in the cell loading channel, which enable precise control of timing and profile of the chemokine gradients applied on cells interacting with SLB. The hydrogel barriers are formed in pillar-free channels through a liquid pinning process, which eliminates complex cleanroom-based fabrications and distortion of chemoattractant gradient by pillars in typical microfluidic hydrogel barrier designs. As a proof-of-concept, we formed an SLB tethered with ICAM-1, and demonstrated its lateral mobility and different migratory behavior of Jurkat T cells on it from those on immobilized ICAM-1, under a gradient of chemokine CXCL12. Our platform can thus be widely used to investigate membrane-bound chemotaxis such as in cancer, immune, and stem cells.