Detection of AKR1B10 in Peripheral Blood by Anti-AKR1B10-Conjugated CdTe/CdS Quantum Dots.

BACKGROUND: Aldo-ketoreductase family 1 member B10 (AKR1B10) is a novel prognostic predictor and therapeutic target for colorectal cancer (CRC), and enzyme-linked immunosorbent assays (ELISAs) and electrochemiluminescence (ELC) assays are sample-consuming and high-cost methods. Therefore, it is very necessary to develop a new, simple, and fast yet highly sensitive and specific method for the detection of AKR1B10 in serum. Semiconducting quantum dots (QDs) possess a high fluorescence quantum yield, stability against photobleaching, and size-controlled luminescence properties; thus, they are suitable for photoelectrochemical tumor marker detection, especially in complex biological samples. However, CdTe/CdS QDs have not been applied for the detection of AKR1B10 in serum. METHODS: AKR1B10 in peripheral blood has been established using anti-AKR1B10-conjugated CdTe/CdS QDs and measurements. The assay sensitivity was determined by measuring the quenched fluorescence intensity of AKR1B10 at 0.5, 1, 2, 5, or 10 ng/mL in phosphate-buffered solution (PBS) or 0.25%, 0.5%, 1.0%, 2.0%, or 5% human serum diluted in PBS. The assay was optimized under different pH values (7.00 - 7.40) for different reaction durations (10 - 60 minutes). The specificity of anti-AKR1B10-QDs was determined by testing the inhibition of AKR1B10 activity with carcinoembryonic antigen (CEA), immunoglobulin G (IgG), or alpha-fetoprotein (AFP), each at 1 ng/mL. RESULTS: Under the optimized incubation time (30 minutes) at room temperature and optimal pH (7.1 - 7.2), a correlation between the decreased fluorescence intensity of anti-AKR1B10-conjugated CdTe/CdS QDs and the concentration of AKR1B10 in the range from 0.05 to 100 ng/mL was established. The assay was sensitive for the detection of AKR1B10 in the range from 0.05 to 100 ng/mL, and the detection limit was 0.02 ng/mL. The assay presented a high specificity because the anti-AKR1B10-conjugated CdTe/CdS QDs only reacted with AKR1B10 in the sera in the presence of CEA, IgG, or AFP. CONCLUSIONS: In conclusion, the immunofluorescence assay to detect AKR1B10 in serum using anti-AKR1B10-conjugated CdTe/CdS QDs was simple and fast yet presented high sensitivity and specificity. Our findings provide a promising tool for the early prediction of CRC.

Recent advances in flame retardant and mechanical properties of polylactic acid: A review.

The large-scale application of ecofriendly polymeric materials has become a key focus of scientific research with the trend toward sustainable development. Mechanical properties and fire safety are two critical considerations of biopolymers for large-scale applications. Polylactic acid (PLA) is a flammable, melt-drop carrying, and strong but brittle polymer. Hence, it is essential to achieve both flame retardancy and mechanical enhancement to improve safety and broaden its application. This study reviews the recent research on the flame retardant functionalization and mechanical reinforcement of PLA. It classifies PLA according to the type of the flame retardant strategy employed, such as surface-modified fibers, modified nano/micro fillers, small-molecule and macromolecular flame retardants, flame retardants with fibers or polymers, and chain extension or crosslinking with other flame retardants. The functionalization strategies and main parameters of the modified PLA systems are summarized and analyzed. This study summarizes the latest advances in the fields of flame retardancy and mechanical reinforcement of PLA.

Surface Modification of Ammonium Polyphosphate for Enhancing Flame-Retardant Properties of Thermoplastic Polyurethane.

Currently, the development of efficient and environmentally friendly flame-retardant thermoplastic polyurethane (TPU) composite materials has caused extensive research. Ammonium polyphosphate (APP) is used as a general intumescent flame retardant to improve the flame retardancy of TPU. In this paper, we developed a functionalized APP flame retardant (APP-Cu@PDA). Adding only 5 wt% of APP-Cu@PDA into TPU can significantly improve the flame-retardant's performance of the composite material, reflected by a high LOI value of 28% with a UL-94 test of V-0 rating. Compared with pure TPU, the peak heat release rate, total heat release, peak smoke release rate, and total smoke release were reduced by 82%, 25%, 50%, and 29%, respectively. The improvements on the flame-retardant properties of the TPU/5%APP-Cu@PDA composites were due to the following explanations: Cu2+-chelated PDA has a certain catalytic effect on the carbonization process, which can promote the formation of complete carbon layers and hinder the transfer of heat and oxygen. In addition, after adding 5% APP-Cu@PDA, the tensile strength and elongation at the break of TPU composites did not decrease significantly. In summary, we developed a new flame-retardant APP-Cu@PDA, which has better flame-retardant properties than many reported TPU composites, and its preparation process is simple and environmentally friendly. This process can be applied to the industrial production of flame retardants in the future.