Investigation of non-covalent complex formation between 2-(4-hydroxyphenylazo) benzoic acid and α-Cyclodextrin in solid and solution forms

Advancements in the preparation technology of small molecule artificial antigens and their specific antibodies: a comprehensive review

Small molecules find extensive application in medicine, food safety, and environmental studies, particularly in biomedicine. Immunoassay technology, leveraging the specific recognition between antigens and antibodies, offers a superior alternative to traditional physical and chemical analysis methods. This approach allows for the rapid and accurate detection of small molecular compounds, owing to its high sensitivity, specificity, and swift analytical capabilities. However, small molecular compounds often struggle to effectively stimulate an immune response due to their low molecular weight, weak antigenicity, and limited antigenic epitopes. To overcome this, coupling small molecule compounds with macromolecular carriers to form complete antigens is typically required to induce specific antibodies in animals. Consequently, the preparation of small-molecule artificial antigens and the production of efficient specific antibodies are crucial for achieving precise immunoassays. This paper reviews recent advancements in small molecule antibody preparation technology, emphasizing the design and synthesis of haptens, the coupling of haptens with carriers, the purification and identification of artificial antigens, and the preparation of specific antibodies. Additionally, it evaluates the current technological shortcomings and limitations while projecting future trends in artificial antigen synthesis and antibody preparation technology.

Inclusion Complexes of Ethanamizuril with β- and Hydroxypropyl-β-Cyclodextrin in Aqueous Solution and in Solid State: A Comparison Study

Ethanamizuril (EZL) is a new anticoccidial drug developed by our Shanghai Veterinary Research Institute. Since EZL is almost insoluble in water, we conducted a study to improve the solubility of EZL by forming inclusion complexes with β-cyclodextrin (β-CD) and hydroxypropyl-β-cyclodextrin (HP-β-CD). In this study, we performed molecular docking and then systematically compared the interactions of EZL with β-CD and HP-β-CD in both aqueous solution and the solid state, aiming to elucidate the solubilization effect and mechanism of cyclodextrins (CDs). The interactions were also examined in the solid state using DSC, PXRD, and FT-IR. The interactions of EZL with CDs in an aqueous solution were investigated using PSA, UV-vis spectroscopy, MS, 1H NMR, and 2D ROESY. The results of phase solubility experiments revealed that both β-CD and HP-β-CD formed inclusion complexes with EZL in a 1:1 molar ratio. Among them, HP-β-CD exhibited higher Kf (stability constant) and CE (complexation efficiency) values as well as a stronger solubilization effect. Furthermore, the two cyclodextrins were found to interact with EZL in a similar manner. The results of our FT-IR and 2D ROESY experiments are in agreement with the theoretical results derived from molecular simulations. These results indicated that intermolecular hydrogen bonds existing between the C=O group on the triazine ring of EZL and the O-H group of CDs, as well as the hydrophobic interactions between the hydrogen on the benzene ring of EZL and the hydrogen of CDs, played crucial roles in the formation of EZL/CD inclusion complexes. The results of this study can lay the foundation for the future development of high-concentration drinking water delivery formulations for EZL.

Functional Chitosan-Based Composite Film Incorporated with 3-(Methylthio) Propyl Isothiocyanate/α-Cyclodextrin Inclusion Complex for Chicken Meat Preservation

The 3-(Methylthio) propyl isothiocyanate (MTPITC)-loaded inclusion complex prepared by α-cyclodextrin (α-CD) was incorporated into chitosan (CS) film to fabricate a packaging material for fresh chicken meat preservation. Scanning electron microscope images indicated homogenous dispersion of the MTPITC-α-CD in CS polymer. Fourier-transform infrared and X-ray diffraction techniques revealed that MTPITC-α-CD was incorporated into the CS film matrix by the physical interactions. The introduction of MTPITC-α-CD improved the UV-vis light-blocking ability, with a slight loss of transparency. Although the water solubility and water vapor barrier capacity were not significantly influenced by the addition of MTPITC-α-CD, the antioxidant attribute was significantly enhanced. The CS-MTPITC-α-CD film displayed obvious and sustained suppressive effects against Salmonella typhimurium, with the inhibition zone diameters of 14.7 mm at 12 h and 7.3 mm at 24 h, respectively. Moreover, the quality index analysis indicated that the CS-MTPITC-α-CD film-wrapped fresh chicken, during refrigerated storage, exhibited better preservative efficacy than the control groups, with the total viable counts of 6.5 Log CFU/g, total volatile base nitrogen of 8.4 mg/100 g, pH of 6.6, thiobarbituric acid-reactive substances of 0.2 mg/kg, and the sensory score of 5 at day 16. Collectively, these results suggest that CS-MTPITC-α-CD film is a prospective packaging candidate for delaying the quality deterioration of chicken meat.

A Bioactive Chitosan-Based Film Enriched with Benzyl Isothiocyanate/α-Cyclodextrin Inclusion Complex and Its Application for Beef Preservation

A bioactive packaging material based on chitosan (CS) incorporated with benzyl isothiocyanate (BITC) and α−cyclodextrin (α−CD) was fabricated to evaluate its preservative effects on fresh beef stored at 4 °C for 12 d according to the quality analysis. The Fourier-transform infrared (FTIR) spectrum revealed that the major structural moiety of BITC was embedded in the cavity of α−CD, except for the thiocyanate group. FTIR and X-ray diffraction analysis further verified that intermolecular interactions were formed between the BITC−α−CD and CS film matrix. The addition of BITC−α−CD decreased the UV light transmittance of pure CS film to lower than 63% but still had enough transparency for observing packaged items. The CS−based composite film displayed a sustainable antibacterial capacity and an enhanced antioxidant activity. Moreover, the total viable counts, total volatile base nitrogen, pH, thiobarbituric acid–reactive substances, and sensory evaluation of the raw beef treated with the CS−based composite film were 6.31 log colony-forming unit (CFU)/g, 19.60 mg/100 g, 6.84, 0.26 mg/kg, and 6.5 at 12 days, respectively, indicating the favorable protective efficacy on beef. These results suggested that the fabricated CS−based composite film has the application potential to be developed as a bioactive food packaging material, especially for beef preservation.