ABSTRACT
As the infection by Helicobacter pylori (H. pylori, HP) remains for a lifetime and may induce diseases such as gastric cancer, it is vital to detect and diagnose it. A new non-invasive indirect enzyme-linked immunosorbent assay (iELISA) method based on nano-flowers (NFs) is very advantageous for the sensitive detection of HP. Furthermore, the established iELISA method based on the organic-inorganic bifunctional hybrid nano-flowers including rabbit polyclonal antibody of HP labeled with peroxidase from horseradish (R-HP-Ab-HRP@Cu2+ NFs) showed linearity with HP at a concentration of 0-105 CFU mL-1 (R2 = 0.9997). Moreover, the limit of detection (LOD) reached 50 CFU mL-1, and not only was the detection sensitivity 20 times higher than that based on rabbit polyclonal antibody of HP labeled with peroxidase from horseradish (R-HP-Ab-HRP) but also the stability of R-HP-Ab-HRP in NFs was improved. In addition, the OD450 nm value was still linearly related to the concentration of HP at a range of 0-105 CFU mL-1 (R2 = 0.9952) with a LOD of 50 CFU mL-1 in an artificial saliva system. This study provided a sensitive, low-cost and convenient method for the non-invasive detection of HP.
Subject(s)
Helicobacter pylori , Stomach Neoplasms , Animals , Antibodies , Enzyme-Linked Immunosorbent Assay , Limit of Detection , RabbitsABSTRACT
BACKGROUND: Coenzyme Q10 (Q10) is a powerful lipophilic antioxidant with poor solubility in aqueous media. Curcumin (Cur) is a natural polyphenolic phytochemical molecule with poor aqueous solubility. The liposome is an improved administration of drugs because it is biocompatible and permeable for nutraceutical delivery. Chitosan, a hydrophilic polymer, is often used as a polymer coating for its good biocompatible and biodegradable properties, and its relatively low toxicity level. METHODS: Q10 and Cur co-loaded liposomes coated with chitosan (Q10-Cur-Lip-Chi) were constructed. The co-encapsulation of Q10 and Cur in liposomes coated with chitosan was verified by TEM, DLS, DSC, FT-IR, and XRPD. The release profile and antioxidant activity of Q10-Cur-Lip-Chi were accessed. RESULTS: The particle size of Q10-Cur-Lip-Chi was about 1440 nm with narrow particle distribution. A satisfactory encapsulation efficiency (EE) of Q10 was about 98%, and 25% for that of Cur. Q10-Cur- Lip-Chi showed higher solubility and better pH resistance with 98.5% of Q10 and Cur retention at pH 7.0 - 9.0. Q10-Cur-Lip also showed great salt stability with a vesicle size change of less than 5%. PSof Q10-Cur-Lip-Chi changed less than 10% at 4°C of storage. Q10-Cur-Lip-Chi also exhibited a good controlled release profile with its accumulative release of less than 34% for Q10 and 30% for curcumin after 24 h. The Q10-Cur-Lip-Chi performed a synergistic effect on antioxidant activity reaching 41.86±1.84%, which was 5.9 times higher than that of Q10, 2.5 times higher than that of Cur, and 1.7 times higher than that of the mixture. CONCLUSION: The co-encapsulation Q10-Cur-Lip-Chi improves the solubility and stability of Q10 and Cur for good release performance and antioxidative activity.
Subject(s)
Chitosan , Curcumin , Liposomes/chemistry , Antioxidants/pharmacology , Curcumin/chemistry , Solubility , Chitosan/chemistry , Lip , Spectroscopy, Fourier Transform Infrared , Particle SizeABSTRACT
Periodontitis is a bacterial biofilm-induced oral disease, mostly caused by Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans) and Porphyromonas gingivalis (P. gingivalis). Oral administration of chicken egg yolk antibody (IgY) is a promising nutritional strategy to control pathogen infections. The objective of this study was to produce an A. actinomycetemcomitans- and P. gingivalis-specific IgY and evaluate its effects on bacterial agglutination and biofilm formation. Thirty laying hens were immunized with a complex of lysate containing typical molecular weights of membrane proteins of A. actinomycetemcomitans and P. gingivalis. IgY was isolated by polyethylene glycol 6000 and ammonium sulfate and purified by dialysis. The results of enzyme-linked immunosorbent assay showed that the obtained IgY were specific to both A. actinomycetemcomitans and P. gingivalis. In addition, immunoelectron microscopy scanning and crystal violet staining showed that the IgY could bind to cell wall of the pathogens and efficiently accelerate agglutination and inhibit biofilm formation. Furthermore, the activity of the IgY remained stable at different temperature, pH, and storage period. This is the first report that a novel two-in-one IgY was produced to modulate the agglutination and biofilm formation of A. actinomycetemcomitans and P. gingivalis, suggesting the potential of IgY to control periodontitis caused by oral pathogens.
ABSTRACT
The screening strategy based on α-glucosidase inhibition has been widely employed for the discovery of antidiabetic drugs, but it still faces some challenges in practical applications, such as poor stability of enzyme, high consumption of test compounds, low sensitivity of screening methods and so on. In this work, a bifunctional hybrid enzyme-catalytic metal organic framework reactor (GAA@GOx@Cu-MOF) with a flower-shaped globular structure was innovatively prepared via self-assembling of α-glucosidase (GAA), glucose oxidase (GOx), Cu2+, and 4,4'-bipyridine. It was found that GAA@GOx@Cu-MOF not only enjoyed merits of high stability, selectivity, and sensitivity but also possessed the character of assembly line work, with about 4.58 times enhanced enzyme activity compared with the free enzyme system. Based on the above characteristics, a highly sensitive screening of GAA inhibitors could be achieved with the detection limit of 7.05 nM for acarbose. Furthermore, the proposed method was successfully applied to the screening of oleanolic acid derivatives as potential antidiabetic drugs. Therefore, it was expected that this work could provide new insights and inspirations for the screening of clinical antidiabetic drugs and for further exploration of functional MOF composites.