Capillary Force-Driven Quantitative Plasma Separation Method for Application of Whole Blood Detection Microfluidic Chip.

Separating plasma or serum from blood is essential for precise testing. However, extracting precise plasma quantities outside the laboratory poses challenges. A recent study has introduced a capillary force-driven membrane filtration technique to accurately separate small plasma volumes. This method efficiently isolates 100-200 µL of pure human whole blood with a 48% hematocrit, resulting in 5-30 µL of plasma with less than a 10% margin of error. The entire process is completed within 20 min, offering a simple and cost-effective approach to blood separation. This study has successfully addressed the bottleneck in self-service POCT, ensuring testing accuracy. This innovative method shows promise for clinical diagnostics and point-of-care testing.

Rapid Fabrication of Large-Grain Opal Films and Photonic Crystal Hydrogel Sensors by a Filter Paper-Enhanced Evaporation Chip.

Developing a rapid fabrication method for crack-free opal films is a significant challenge with broad applications. We developed a microfluidic platform known as the "filter paper-enhanced evaporation microfluidic chip" (FPEE-chip) for the fabrication of photonic crystal and inverse opal hydrogel (IOPH) films. The chip featured a thin channel formed by bonding double-sided adhesive poly(ethylene terephthalate) with a polymethyl methacrylate cover and a glass substrate. This channel was then filled with nanosphere colloids. The water was guided to evaporate rapidly at the surface of the filter paper, allowing the nanospheres to self-assemble and accumulate within the channel under capillary forces. Experimental results confirmed that the self-assembly method based on the FPEE-chip was a rapid platform for producing high-quality opal, with centimeter-sized opal films achievable in less than an hour. Furthermore, the filter paper altered the stress release mechanism of the opal films during drying, resulting in fewer cracks. This platform was proven capable of producing large-grain, crack-free opal films of up to 30 mm2 in size. We also fabricated crack-free IOPH pH sensors that exhibited color and size responsiveness to pH changes. The coefficient of variation of the gray color distribution for crack-free IOPH ranged from 0.03 to 0.07, which was lower than that of cracked IOPH (ranging from 0.07 to 0.14). Additionally, the grayscale peak value in 1 mm2 of the crack-free IOPH was more than twice that of the cracked IOPH at the same pH. The FPEE-chip demonstrated potential as a candidate for developing vision sensors.

A compact microfluidic laser-induced fluorescence immunoassay system using avalanche photodiode for rapid detection of alpha-fetoprotein.

Alpha-fetoprotein (AFP), commonly employed for early diagnosis of liver cancer, serves as a biomarker for cancer screening and diagnosis. Combining the high sensitivity and specificity of fluorescence immunoassay (FIA), developing a low-cost and efficient immunoassay system for AFP detection holds significant importance in disease diagnosis. In this work, we developed a miniaturized oblique laser-induced fluorescence (LIF) immunoassay system, coupled with a microfluidic PMMA/paper hybrid chip, for rapid detection of AFP. The system employed an avalanche photodiode (APD) as the detector, and implemented multi-level filtering in the excitation light channel using the dichroic mirror and optical trap. At first, we employed the Savitzky-Golay filter and baseline off-set elimination methods to denoise and normalize the original data. Then the cutoff frequency of the low-pass filter and the reverse voltage of the APD were optimized to enhance the detection sensitivity of the system. Furthermore, the effect of laser power on the fluorescence excitation efficiency was investigated, and the sampling time during the scanning process was optimized. Finally, a four-parameter logistic (4PL) model was utilized to establish the concentration-response equation for AFP. The system was capable of detecting concentrations of AFP standard solution within the range of 1-500 ng/mL, with a detection limit of 0.8 ng/mL. The entire immunoassay process could be completed within 15 min. It has an excellent potential for applications in low-cost portable diagnostic instruments for the rapid detection of biomarkers.

The use of biotinylated-EGF-modified gelatin nanoparticle carrier to enhance cisplatin accumulation in cancerous lungs via inhalation.

To develop a polymer-anticancer drug conjugate, we employed gelatin nanoparticles (GPs) as carriers of cisplatin (CDDP) with anticipated improved therapeutic effect and reduced side effects. The anticancer activities of CDDP-incorporated in GPs (GP-Pt) with biotinylated-EGF (bEGF) modification (GP-Pt-bEGF) were studied. GP-Pt-bEGF with EGFR affinity produced much higher Pt concentrations in A549 cells (high EGFR expression) than in HFL1 cells (low EGFR expression). An in vitro anticancer study showed that GP-Pt-bEGF was more potent than free CDDP or GP-Pt because of its rapid effect on the cell cycle as well as a lower IC(50) (1.2microg/ml) that inhibits A549 cell growth. PI staining showed that cells treated with GP-Pt-bEGF for only 4h had the highest sub-G1 population. The CDDP formulations - free CDDP, GP-Pt, and GP-Pt-bEGF - were given by intratumorous injections to SCID mice in a subcutaneous model. This treatment showed that GP-Pt-bEGF had stronger anti-tumor activity and was less toxic than free CDDP in vivo. Mice treated with GP-Pt-bEGF showed slight body weight loss, whereas free CDDP treatment at the same dose caused a body weight loss of 20-30%. Furthermore, these formulations were given to mice with lung cancer via aerosol delivery. This treatment showed that inhaled GP-Pt-bEGF could target EGFR-overexpressing cells to achieve high cisplatin dosage in cancerous lungs. To summarize, gelatin nanoparticles loaded with CDDP and decorated with EGF tumor-specific ligand were successfully developed. Their in vitro and in vivo targeting ability and anticancer effect were confirmed. The aerosol delivery of the nanodrug carrier was demonstrated. Simple aerosol delivery of targeted drug carriers may prove useful for the clinical treatment of lung cancer patients.