Exclcirc (Suzhou) Biomedical Co., Ltd. has been granted a patent by the United States Patent and Trademark Office (USPTO) for its innovative method of synthesizing and preparing circRNA molecules. 

CircRNAs are an important class of the regulatory non-codingRNA. A circRNA usually includes an enclosed circular structure, and is generally not affected by RNA exonucleases.

CircRNAs are often stable in nature and can regulate gene expression through a variety of mechanisms. At present, circRNAs can be divided into three categories: exonic circularRNAs formed based on an exon by back splicing; intronic circularRNAs formed based on an intron region by a process of debranch inhibition; and exon-intron circular RNAs formed based on an exon and an intron.

Researchers have found the presence of the circRNAs in viruses, yeast, fruit flies, nematodes, mice, monkeys, and humans. Due to the enclosed structure of the circRNAs, these molecules can accumulate continuously due to their stability and have the capability of avoiding degradation. The disclosed circularization methods in prior art are too complex and require a large number of enzymes. For example, translatable or biologicallyactive circRNA is generated in a eukaryotic cell through two consecutive steps of transesterification with the help of the homologous arm; moreover, the circRNA is mainly purified using size exclusion chromatography (SEC) or other methods based on molecular weight differences between the reaction products (e.g., the circRNA and a precursor linear RNA of the circRNA). However, due to the minimal difference between molecular weights of the circRNA and the linear RNA, the purification of the circRNA pose extensive challenges (e.g., not efficient in separating circRNA from the linear RNA present in the reaction products).

Therefore, it is desirable to provide preparation methods of circRNAs that can minimize circularization operations, reduce the requirement of raw materials, lower the production costs, enhance the circularization efficiency, and improve the purification effect. We have developed a more efficient RNA cyclization method, streamlining the preparation of circRNA molecules to achieve greater simplicity and effectiveness. The synthesis and preparation method for circRNA has now been officially granted a patent by the United States Patent and Trademark Office (USPTO). We warmly welcome researchers, partners, and industry professionals to explore and utilize this advanced technology.