Preparation and Immunological Reactions of a Purified Egg Allergen Ovotransferrin

Construction of Iron-Scavenging Hydrogel via Thiol-Ene Click Chemistry for Antibiotic-Free Treatment of Bacterial Wound Infection

Bacteria, especially drug-resistant strains, can quickly cause wound infections, leading to delayed healing and fatal risk in clinics. With the growing need for alternative antibacterial approaches that rely less on antibiotics or eliminate their use altogether, a novel antibacterial hydrogel named Ovtgel is developed. Ovtgel is formulated by chemically crosslinking thiol-modified ovotransferrin (Ovt), a member of the transferrin family found in egg white, with olefin-modified agarose through thiol-ene click chemistry. Ovt is designed to sequester ferric ions essential for bacterial survival and protect wound tissues from damages caused by the reactive oxygen species (ROS) generated in Fenton reactions. Experimental data have shown that Ovtgel significantly enhances wound healing by inhibiting bacterial growth and shielding tissues from ROS-induced harms. Unlike traditional antibiotics, Ovtgel targets essential trace elements required for bacterial survival in the host environment, preventing the development of drug resistance in pathogenic bacteria. Ovtgel exhibits excellent biocompatibility due to the homology of Ovt to mammalian transferrin. This hydrogel has the potential to serve as an effective antibiotic-free solution for combating bacterial infections.

Epitope mapping and the effects of various factors on the immunoreactivity of main allergens in egg white

Egg white has high protein content and numerous biological/functional properties. However, reported allergenicity for some of the proteins in egg white is an issue that needs to be paid exclusive attention. A consideration of the structure of IgE epitopes and their sequences, as well as a comprehensive understanding of the effects of various processes on epitopes and the impact of the gastrointestinal tract on them, can help target such issues. The current study focuses on the identified IgE epitopes in egg white proteins and evaluation of the effects of the gastrointestinal digestion, carbohydrate moiety, food matrix, microbial fermentation, recombinant allergen, heat treatment, Maillard reaction and combination of various processes and gastrointestinal digestion on egg white allergenicity. Although the gastrointestinal tract reduces the immunoreactivity of native egg white proteins, some of the IgE epitope-containing fragments remain intact during the digestion process. It has been found that the gastrointestinal tract can have both positive and negative impacts on the IgE binding activities of egg white proteins. Elimination of the carbohydrate moiety leads to a reduction in the immunoreactivity of ovalbumin. But, such effects from the carbohydrate parts in the IgE binding activity need to be explored further. In addition, the interaction between the egg white proteins and the food matrix leads to various effects from the gastrointestinal tract on the digestion of egg white proteins and their subsequent immunoreactivity. Further on this matter, studies have shown that both microbial fermentation and Maillard reaction can reduce the IgE binding activities of egg white proteins. Also, as an alternate approach, the thermal process can be used to treat the egg white proteins, which may result in the reduction or increase in their IgE binding activities depending on the conditions used in the process. Overall, based on the reported data, the allergenicity levels of egg white proteins can be mitigated or escalated depending on the conditions applied in the processing of the food products containing egg white. So far, no practical solutions have been reported to eliminate such allergenicity.

Aptamer-Based Fluorescent Biosensor for the Rapid and Sensitive Detection of Allergens in Food Matrices

Food allergies have seriously affected the life quality of some people and even endangered their lives. At present, there is still no effective cure for food allergies. Avoiding the intake of allergenic food is still the most effective way to prevent allergic diseases. Therefore, it is necessary to develop rapid, accurate, sensitive, and reliable analysis methods to detect food allergens from different sources. Aptamers are oligonucleotide sequences that can bind to a variety of targets with high specificity and selectivity, and they are often combined with different transduction technologies, thereby constructing various types of aptamer sensors. In recent years, with the development of technology and the application of new materials, the sensitivity, portability, and cost of fluorescence sensing technology have been greatly improved. Therefore, aptamer-based fluorescence sensing technology has been widely developed and applied in the specific recognition of food allergens. In this paper, the classification of major allergens and their characteristics in animal and plant foods were comprehensively reviewed, and the preparation principles and practical applications of aptamer-based fluorescence biosensors are summarized. In addition, we hope that this article can provide some strategies for the rapid and sensitive detection of allergens in food matrices.