In terms of molecular properties, the structure of sialic acid contains carboxyl and ketone groups. It can bind with other sugars and proteins via glycosidic bonds to form intricate glycan chains on cell surfaces. These glycan chains serve as crucial media for intercellular communication. During embryonic development, sialic acid takes part in cell migration and differentiation, mediates cell recognition and signal transduction, and underpins fundamental vital activities of the body.

Continuous research has uncovered multiple physiological potentials of sialic acid. In terms of immune mechanisms, it helps the human body identify exogenous pathogens and modulates the activity of immune cells. Meanwhile, certain viruses and bacteria exploit cell-surface sialic acid to achieve immune evasion, which renders sialic acid a key research target for anti-infection studies. Moreover, sialic acid forms a protective layer on cell surfaces to curb microbial adhesion and invasion, shielding cells from damage caused by external physical and chemical irritants.

Animal experiments in neuroscience have revealed a correlation between sialic acid and memory as well as cognitive performance. Tests conducted on mice with Alzheimer’s disease models showed that supplementary sialic acid markedly improved the memory of diseased mice and boosted memory levels in healthy ones. This indicates its potential value for nerve cell development and the maintenance of neurological functions, though further human clinical trials are required to verify these effects.

In addition, studies have confirmed the antioxidant capacity of sialic acid. It binds free radicals and inhibits tyrosinase activity, endowing it great development prospects in skincare; its underlying mechanisms are now a major research focus for the cosmetics industry.

Advancements in production technologies lay a vital foundation for the industrialization of sialic acid. In the early stage, sialic acid was extracted naturally from animal tissues. Restricted by raw material sources, this method yielded low output at excessive costs and could not satisfy large-scale market demand. Chemical synthesis involves complicated procedures and carries risks of heavy metal residues. Enzymatic synthesis features mild reaction conditions yet suffers from prohibitively high raw material costs. Thanks to advances in biotechnology, microbial fermentation has become the dominant industrial production method at present, balancing output, cost and safety to deliver stable raw material supply for downstream industries.

Today, sialic acid has achieved industrial application across diverse fields. In the food sector, the US Food and Drug Administration (FDA) and the European Food Safety Authority (EFSA) have successively approved the use of sialic acid in general food and infant formula products. In 2017, China listed sialic acid as a novel food ingredient, permitting its application in infant formula milk powder and dietary nutritional supplements, with a regulated maximum daily intake of 500 milligrams.

For cosmetics, N-acetylneuraminic acid was officially approved as a new cosmetic raw material in China in 2021. Numerous skincare brands have incorporated it into serums, facial masks and other products to explore its skincare benefits.

Remarkable progress has also been made in pharmaceutical research. Based on the binding mechanism between sialic acid and influenza viruses, researchers have developed therapeutic anti-influenza drugs, which have pioneered new approaches for the research and development of innovative antiviral medicines.

Industry experts caution that most existing research data on sialic acid stem from in vitro tests and animal models, and many of its purported effects have not been fully validated through human clinical trials. As a raw material, sialic acid cannot replace medicines for disease prevention or treatment. Consumers ought to rationally distinguish marketing claims and view its research value and practical effects objectively.