Fast advancements of microfabrication processes in past two decades have reached to a fairly matured stage that we can manufacture a wide range of microfluidic devices. At present, the main challenge ...is the control of nanoscale properties on the surface of lab-on-a-chip to satisfy the need for biomedical applications. For example, poly(dimethylsiloxane) (PDMS) is a commonly used material for microfluidic circuitry, yet the hydrophobic nature of PDMS surface suffers serious nonspecific protein adsorption. Thus the current major efforts are focused on surface molecular property treatments for satisfying specific needs in handling macro functional molecules. Reviewing surface modifications of all types of materials used in microfluidics will be too broad. This review will only summarize recent advances in nonbiofouling PDMS surface modification strategies applicable to microfluidic technology and classify them into two main categories: (1) physical approach including physisorption of charged or amphiphilic polymers and copolymers, as well as (2) chemical approach including self assembled monolayer and thick polymer coating. Pros and cons of a collection of available yet fully exploited surface modification methods are briefly compared among subcategories.
The coffee ring phenomenon has long been known for its ability to concentrate particles at the rim of a dried liquid droplet, yet little is known about its particle separation capability. Here, we ...elucidate the physics of particle separation during coffee ring formation, which is based on a particle-size selection mechanism near the contact line of an evaporating droplet. On the basis of this mechanism, we demonstrate nanochromatography of three relevant biological entities (proteins, micro-organisms, and mammalian cells) in a liquid droplet, with a separation resolution on the order of ∼100 nm and a dynamic range from ∼10 nm to a few tens of micrometers. These findings have direct implications for developing low-cost technologies for disease diagnostics in resource-poor environments.
This paper reports the successful development of the first IC-integrated flexible MEMS shear-stress sensor skin. The sensor skin is 1 cm wide, 2 cm long, and 70 /spl mu/m thick. It contains 16 ...shear-stress sensors, which are arranged in a 1-D array, with on-skin sensor bias, signal-conditioning, and multiplexing circuitry. We further demonstrated the application of the sensor skin by packaging it on a semicylindrical aluminum block and testing it in a subsonic wind tunnel. In our experiment, the sensor skin has successfully identified both the leading-edge flow separation and stagnation points with the on-skin circuitry. The integration of IC with MEMS sensor skin has significantly simplified implementation procedures and improved system reliability.
The gender disparity of hepatocellular carcinoma (HCC) is most striking in hepatitis B virus (HBV)‐related cases. The majority of such HCC cases contain integrated HBV, and some hotspot integrations, ...such as those in the telomerase reverse transcriptase gene (TERT) promoter, activate gene expression to drive carcinogenesis. As the HBV genome contains both androgen‐responsive and estrogen‐responsive motifs, we hypothesized that the integrated HBV DNA renders a similar regulation for downstream gene expression and thus contributes to male susceptibility to HCC. To test this hypothesis, the HBV integration sites and the common mutations in the TERT promoter and tumor protein P53 (TP53) coding region were analyzed in 101 HBV‐related HCC cases using a capture‐next‐generation sequencing platform. The results showed that both HBV integration and –124G>A mutation in the TERT promoter region, occurring in a mutually exclusive manner, were more frequent in male than in female patients with HCC (integration: 22/58 male patients with HCC, 6/36 female patients with HCC, P = 0.0285; –124G>A: 17/62 male patients with HCC, 3/39 female patients with HCC, P = 0.0201; in combination, 39/62 male patients with HCC, 9/39 female patients with HCC, P < 0.0001). The effects of sex hormone pathways on the expression of TERT with both genetic changes were investigated using a reporter assay. HBV integration in the TERT promoter rendered the TERT transcription responsive to sex hormones, with enhancement by androgen receptor (AR) but suppression by estrogen receptor, both of which were dependent on hepatocyte nuclear factor 4 alpha. Besides, AR also increased TERT expression by targeting TERT promoter mutations in a GA binding protein transcription factor subunit alpha–dependent manner. Conclusion: TERT elevation by AR through integrated HBV and point mutation at the TERT promoter region was identified as a mechanism for the male dominance of HBV‐related HCCs; telomerase and AR thus may be targets for intervention of HCC.
Background and Aims
Early recurrence of hepatocellular carcinoma (HCC) after surgical resection compromises patient survival. Timely detection of HCC recurrence and its clonality is required to ...implement salvage therapies appropriately. This study examined the feasibility of virus‐host chimera DNA (vh‐DNA), generated from junctions of hepatitis B virus (HBV) integration in the HCC chromosome, as a circulating biomarker for this clinical setting.
Approach and Results
HBV integration in 50 patients with HBV‐related HCC was determined by the Hybridization capture‐based next‐generation sequencing (NGS) platform. For individual HCC, the vh‐DNA was quantified by specific droplet digital PCR (ddPCR) assay in plasma samples collected before and 2 months after surgery. HBV integrations were identified in 44 out of 50 patients with HBV‐related HCC. Tumor‐specific ddPCR was developed to measure the corresponding vh‐DNA copy number in baseline plasma from each patient immediately before surgery. vh‐DNA was detected in 43 patients (97.7%), and the levels correlated with the tumor sizes (detection limit at 1.5 cm). Among the plasma collected at 2 months after surgery, 10 cases (23.3%) still contained the same signature vh‐DNA detected at baseline, indicating the presence of residual tumor cells. Nine of them (90%) experienced HCC recurrence within 1 year, supporting vh‐DNA as an independent risk factor in predicting early recurrence. Analysis of circulating vh‐DNA at recurrence further helped identify the clonal origin. A total of 81.8% of recurrences came from original HCC clones sharing the same plasma vh‐DNA, whereas 18.2% were from de novo HCC.
Conclusions
vh‐DNA was shown to be a circulating biomarker for detecting the tumor load in majority of patients with HBV‐related HCC and aided in monitoring residual tumor and recurrence clonality after tumor resection.
This study aimed to investigate the survival outcomes of antiviral agents (direct-acting antivirals DAAs or interferon IFN) in patients with hepatitis C virus who underwent liver resection for ...primary hepatocellular carcinoma.
This retrospective single-center study included 247 patients, between 2013 and 2020, being treated with DAAs (n = 93), IFN (n = 73), or no treatment (n = 81). Overall survival (OS), recurrence-free survival (RFS), and risk factors were analyzed.
After a median follow-up time of 50.4 months, the rates of 5-year OS and RFS in the IFN, DAA, and no treatment groups were 91.5% and 55.4%, 87.2% and 39.8%, and 60.9% and 26.7%, respectively. One hundred and twenty-eight (51.6%) patients developed recurrence; recurrence was mostly (86.7%) intrahepatic, and 58 (23.4%) developed early recurrence, most of which received no antiviral treatment. The OS and RFS were similar between patients who received antiviral treatment before (50.0%) and after surgery, but longer survival was observed in patients achieving sustained virologic response. In multivariate analysis, antiviral treatment was protective for OS (hazard ratio HR 0.475, 95% confidence interval CI: 0.242-0.933) with significance but not RFS, in contrast to microvascular invasion (OS HR 3.389, 95% CI: 1.637-7.017; RFS HR 2.594, 95% CI: 1.520-4.008). In competing risk analysis, DAAs (subdistribution HR 0.086, 95% CI: 0.007-0.991) were protective against hepatic decompensation events but not recurrence events.
In patients with hepatitis C virus, antiviral treatment suggested OS benefit for primary hepatocellular carcinoma after resection, and DAAs might be protective against hepatic decompensation. Following adjustment for oncological factors, IFN and DAA treatment was not significantly advantageous relative to the other.
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•Most HCC tumors displayed similar tumor immune microenvironments among different regions within each tumor.•A single-region sample might be reliable to evaluate the tumor immune ...microenvironment of the entire HCC tumor.•Most HCC tumors displayed uniform expression of PD-L1 in different regions within each tumor.•Intratumor tertiary lymphoid structures are rare in HCC, and are prone to spatial heterogeneity.
Intratumor heterogeneity has frequently been reported in patients with hepatocellular carcinoma (HCC). Thus, the reliability of single-region tumor samples for evaluation of the tumor immune microenvironment is also debatable. We conducted a prospective study to analyze the similarity in tumor immune microenvironments among different regions of a single tumor.
Multi-region sampling was performed on newly resected tumors. The tumor immune microenvironment was evaluated by immunohistochemical staining of PD-L1, CD4, CD8, CD20, FoxP3, DC-LAMP (or LAMP3), CD68, MPO, and tertiary lymphoid structures (TLSs). PD-L1 expression was manually quantified according to the percentage of PD-L1-stained tumor or stromal cells. The densities (number/mm2) of immune cells and the number of TLSs per sample were determined by whole-section counting. RNA-sequencing was applied in selected samples. Similarities in tumor immune microenvironments within each tumor were evaluated by multivariate Mahalanobis distance analyses.
Thirteen tumors were collected from 12 patients. The median diameter of tumors was 9 cm (range 3–16 cm). A median of 6 samples (range 3–12) were obtained from each tumor. Nine (69.2%) tumors exhibited uniform expression of PD-L1 in all regions of the tumor. Out of 13 tumors analyzed by immunohistochemical staining, 8 (61.5%) tumors displayed a narrow Mahalanobis distance for all regions within the tumor; while 8 (66.7%) of the 12 tumors analyzed by RNA-sequencing displayed a narrow Mahalanobis distance. Immunohistochemistry and RNA-sequencing had a high concordance rate (83.3%; 10 of 12 tumors) for the evaluation of similarities between tumor immune microenvironments within a tumor.
A single-region tumor sample might be reliable for the evaluation of tumor immune microenvironments in approximately 60–70% of patients with HCC.
Heterogeneity in the regional immune microenvironments of tumors has been reported in patients with hepatocellular carcinoma. This heterogeneity could be an obstacle when trying to reliably evaluate the immune microenvironment of an entire tumor using only a single-region tumor sample, which may be the only option in patients with more advanced disease. Our study utilized both immunohistochemical and transcriptomic analyses to demonstrate that a single-region sample is reliable for evaluation of tumor immune microenvironments in 60–70% of patients with hepatocellular carcinoma.
Tuberculosis (TB) remains a major global public health problem, and improved treatments are needed to shorten duration of therapy, decrease disease burden, improve compliance, and combat emergence of ...drug resistance. Ideally, the most effective regimen would be identified by a systematic and comprehensive combinatorial search of large numbers of TB drugs. However, optimization of regimens by standard methods is challenging, especially as the number of drugs increases, because of the extremely large number of drug–dose combinations requiring testing. Herein, we used an optimization platform, feedback system control (FSC) methodology, to identify improved drug–dose combinations for TB treatment using a fluorescence-based human macrophage cell culture model of TB, in which macrophages are infected with isopropyl β-D-1-thiogalactopyranoside (IPTG)-inducible green fluorescent protein (GFP)-expressing Mycobacterium tuberculosis (Mtb). On the basis of only a single screening test and three iterations, we identified highly efficacious three- and four-drug combinations. To verify the efficacy of these combinations, we further evaluated them using a methodologically independent assay for intramacrophage killing of Mtb; the optimized combinations showed greater efficacy than the current standard TB drug regimen. Surprisingly, all top three- and four-drug optimized regimens included the third-line drug clofazimine, and none included the first-line drugs isoniazid and rifampin, which had insignificant or antagonistic impacts on efficacy. Because top regimens also did not include a fluoroquinolone or aminoglycoside, they are potentially of use for treating many cases of multidrug- and extensively drug-resistant TB. Our study shows the power of an FSC platformto identify promising previously unidentified drug–dose combinations for treatment of TB.
The hydrophobicity of a surface can be enhanced by physical textures. However, no existing theories of surface wetting can provide guidance to pinpoint the texture size requirement to achieve ...super/ultrahydrophobicity. Here, we show that the three-phase contact line tension, τ, is an important link to understand the dependence of macroscopic wetting on physical texture size in an ideal Cassie regime. Specifically, we show that texture size is the dominant parameter in determining surface hydrophobicity when the size approaches a limiting physical length scale, as defined by τ and the surface tension of the liquid.
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