Determination of parvovirus antibodies in canine serum using magnetic bead-based chemiluminescence immunoassay.

Canine parvovirus type 2 (CPV-2), as a highly contagious and potentially fatal disease of dogs and many other carnivores, usually causes severe gastroenteritis and myocarditis. Therefore, it is very necessary and urgent to have an accurate method to determine the CPV-2 antibodies (CPV-2-Ab) in canine samples. Here, a magnetic bead-based chemiluminescence immunoassay was established and optimized to detect the concentration of CPV-2-Ab in serum. And a commercial assay was also used to evaluate the consistency with our method. After optimization of the detective system, the CPV-2-Ab was captured by CPV-antigen-magnetic bead (8.3 µg/mL); then combined with the conjugation of anti-canine IgG antibody-acridinium ester (0.36 µg/mL). Finally, collected the signal (read the luminosity) after 1 H reaction time. The linear correlation coefficient (R2 ) is 0.9924. The limit of detection (sensitivity) is 0.36 ng/mL (the linear dynamic range: 1.32-93.75 ng/mL), and the average recovery is 100.89% without cross-reactions with other canine viral antibodies. The results' correlation between commercial assays and this method is 0.9888. This immunoassay establishes that it has high sensitivity, accuracy, and specificity in clinical analysis, indicating that this method could be suitable for quantitative detection of CPV-2-Ab and evaluation of vaccination effect.

Interplay of stimuli-responsiveness, drug loading and release for a surface-engineered dendrimer delivery system.

The objectives of this study were to generate novel thermo and pH dual responsive poly(amidoamine) (PAMAM) via precise surface engineering, and investigate the interplay of dendrimer stimuli-responsiveness and the loading and release properties of a model agent, vitamin E acetate (VEAc). A higher dendrimer generation and maximized VEAc loading at elevated pH all contributed to a lower cloud point (CP) of the dendrimer-VEAc complex. The drug loading in G3.5 surface-engineered PAMAM was 22 mol/mol (pH 7.0) and 10 mol/mol (pH 5.0), which corresponded to a complex CP value at ca. 13 °C (pH 7.0) and 46 °C (pH 5.0), respectively. At physiological conditions, only less than 40% of VEAc was liberated when reaching the plateau, whilst more than 90% of VEAc was released from such system within 6 h at pH 5.0. This was due to the transition of dendrimer surface from dehydrated state to hydrated state upon pH dropping, enabling rapid drug release for therapeutic action. This smart stimuli-responsive dendritic delivery system holds promise for the efficient drug delivery to tissues with pH abnormality such as tumor.