In vitro development of donated frozen-thawed human embryos in a prototype static microfluidic device: a randomized controlled trial.

OBJECTIVE: To compare the development of human embryos in microfluidic devices with culture in standard microdrop dishes, both under static conditions. DESIGN: Prospective randomized controlled trial. SETTING: In vitro fertilization laboratory. PATIENT(S): One hundred eighteen donated frozen-thawed human day-4 embryos. INTERVENTION(S): Random allocation of embryos that fulfilled the inclusion criteria to single-embryo culture in a microfluidics device (n = 58) or standard microdrop dish (n = 60). MAIN OUTCOME MEASURE(S): Blastocyst formation rate and quality after 24, 28, 48, and 72 hours of culture. RESULT(S): The percentage of frozen-thawed day-4 embryos that developed to the blastocyst stage did not differ significantly in the standard microdrop dishes and microfluidic devices after 28 hours of culture (53.3% vs. 58.6%) or at any of the other time points. The proportion of embryos that would have been suitable for embryo transfer was comparable after 28 hours of culture in the control dishes and microfluidic devices (90.0% vs. 93.1%). Furthermore, blastocyst quality was similar in the two study groups. CONCLUSION(S): This study shows that a microfluidic device can successfully support human blastocyst development in vitro under static culture conditions. Future studies need to clarify whether earlier stage embryos will benefit from the culture in microfluidic devices more than the tested day-4 embryos because many important steps in the development of human embryos already take place before day 4. Further improvements of the microfluidic device will include parallel culture of single embryos, application of medium refreshment, and built-in sensors. DUTCH TRIAL REGISTRATION NUMBER: NTR3867.

Detection of CTX-II in serum and urine to diagnose osteoarthritis by using a fluoro-microbeads guiding chip.

This study reports a new strategy for simultaneous detection of the C-telopeptide fragments of type II collagen (CTX-II) as a biomarker of osteoarthritis (OA) using a fluoro-microbeads guiding chip. As osteoarthritis progresses, the joint components including matrix and cartilage are degraded by proteases. The degraded products such as CTX-II are released into the serum and urine, and the CTX-II concentration in body fluids reflects OA progression. Because the CTX-II has heterogeneous epitope structure in serum (sCTX-II; homodimers) and urine (uCTX-II; monomers or variant monomers), a multiple-sensing device enabling both sandwich and competitive-type immunoassays is required. For multiple assessments of serum and urinary CTX-II, we designed a fluoro-microbeads guiding chip (FMGC) containing multiple sensing areas and connecting channels. Using the approach, the sandwich (sCTX-II) and competition (uCTX-II) assays could be simultaneously performed on a single chip. We designed a fluidic control device enabling selective control of the open-close function of FMGC channels. The immune-specific signal was quantitatively analyzed by counting the number of fluorescent microbeads from the registered images. The results from the developed FMGC assay showed high correlation with those obtained in ELISA. The completion time of the FMGC assay was 24-fold and 3.5-fold shorter than the ELISA for urinary and serum CTX-II. Taken together, it enabled the simultaneous detection of both sCTX-II and uCTX-II. This FMGC-based assay would be a promising tool for monitoring of osteoarthritis.

A microfluidic nano-biosensor for the detection of pathogenic Salmonella.

Rapid detection of pathogenic Salmonella in food products is extremely important for protecting the public from salmonellosis. The objective of the present study was to explore the feasibility of using a microfluidic nano-biosensor to rapidly detect pathogenic Salmonella. Quantum dot nanoparticles were used to detect Salmonella cells. For selective detection of Salmonella, anti-Salmonella polyclonal antibodies were covalently immobilized onto the quantum dot surface. To separate and concentrate the cells from the sample, superparamagnetic particles and a microfluidic chip were used. A portable fluorometer was developed to measure the fluorescence signal from the quantum dot nanoparticles attached to Salmonella in the samples. The sensitivity for detection of pathogenic Salmonella was evaluated using serially diluted Salmonella Typhimurium in borate buffer and chicken extract. The fluorescence response of the nano-biosensor increased with increasing cell concentration. The detection limit of the sensor was 10(3) CFU/mL Salmonella in both borate buffer and food extract.

Lytic enzymes as selectivity means for label-free, microfluidic and impedimetric detection of whole-cell bacteria using ALD-Al2O3 passivated microelectrodes.

Point-of-care (PoC) diagnostics for bacterial detection offer tremendous prospects for public health care improvement. However, such tools require the complex combination of the following performances: rapidity, selectivity, sensitivity, miniaturization and affordability. To meet these specifications, this paper presents a new selectivity method involving lysostaphin together with a CMOS-compatible impedance sensor for genus-specific bacterial detection. The method enables the sample matrix to be directly flown on the polydopamine-covered sensor surface without any pre-treatment, and considerably reduces the background noise. Experimental proof-of-concept, explored by simulations and confirmed through a setup combining simultaneous optical and electrical real-time monitoring, illustrates the selective and capacitive detection of Staphylococcus epidermidis in synthetic urine also containing Enterococcus faecium. While providing capabilities for miniaturization and system integration thanks to CMOS compatibility, the sensors show a detection limit of ca. 10(8) (CFU/mL).min in a 1.5 µL microfluidic chamber with an additional setup time of 50 min. The potentials, advantages and limitations of the method are also discussed.

A compact and versatile microfluidic probe for local processing of tissue sections and biological specimens.

The microfluidic probe (MFP) is a non-contact, scanning microfluidic technology for local (bio)chemical processing of surfaces based on hydrodynamically confining nanoliter volumes of liquids over tens of micrometers. We present here a compact MFP (cMFP) that can be used on a standard inverted microscope and assist in the local processing of tissue sections and biological specimens. The cMFP has a footprint of 175 × 100 × 140 mm(3) and can scan an area of 45 × 45 mm(2) on a surface with an accuracy of ±15 µm. The cMFP is compatible with standard surfaces used in life science laboratories such as microscope slides and Petri dishes. For ease of use, we developed self-aligned mounted MFP heads with standardized "chip-to-world" and "chip-to-platform" interfaces. Switching the processing liquid in the flow confinement is performed within 90 s using a selector valve with a dead-volume of approximately 5 µl. We further implemented height-compensation that allows a cMFP head to follow non-planar surfaces common in tissue and cellular ensembles. This was shown by patterning different macroscopic copper-coated topographies with height differences up to 750 µm. To illustrate the applicability to tissue processing, 5 µm thick M000921 BRAF V600E+ melanoma cell blocks were stained with hematoxylin to create contours, lines, spots, gradients of the chemicals, and multiple spots over larger areas. The local staining was performed in an interactive manner using a joystick and a scripting module. The compactness, user-friendliness, and functionality of the cMFP will enable it to be adapted as a standard tool in research, development and diagnostic laboratories, particularly for the interaction with tissues and cells.