In the field of DNA applications, plasmid DNA (pDNA) has always been highly favored due to its exceptional stability, ease of production, storage, and transportation. However, as scientific research continues to advance, a series of novel DNA types, such as Minicircle DNA (mcDNA), Doggybone DNA (dbDNA), and Close-Ended DNA (ceDNA), have gradually emerged, opening up new avenues for gene therapy and other cutting-edge fields.

mcDNA

mcDNA is derived from the recombination process of parental plasmids, with bacterial elements removed while retaining the circular structure. Its preparation process relies on specific enzymatic activities, such as φC31 integrase, achieving higher recombination efficiency. A notable characteristic of mcDNA is its lack of bacterial sequences, allowing it to rely on small DNA carriers, thereby improving gene expression.

dbDNA

dbDNA has a closed double-stranded conformation, featuring small single-stranded loops at both ends and is completely free of bacterial sequences and antibiotic-resistance genes. Its smaller size facilitates easier delivery into cells and nuclei while exhibiting complete nuclease resistance. The initial form of dbDNA only contains the necessary elements for gene expression, omitting unnecessary sequences, thus possessing powerful gene transfection capabilities and higher protein expression levels.

ceDNA

ceDNA is an engineered double-stranded, linear, covalently closed-end DNA construct containing the target gene and other expression regulatory elements. Its ends are inverted terminal repeats (ITR), providing a construct capacity of thousands of bases, far exceeding the limits of traditional adeno-associated virus (AAV) vectors. The ITR structure of ceDNA is crucial for entering the nucleus, and its expression pattern is consistent with non-integrated episomes. Additionally, the preparation process of ceDNA is rapid and cost-effective, making it suitable for gene therapy research in fields such as rare diseases, vaccines, and oncology.

DNA optimization

In terms of DNA optimization, researchers enhance the expression of transgenic genes by optimizing the intrinsic components of plasmid DNA. Simultaneously, selection markers are replaced, such as substituting ampicillin with kanamycin, to reduce autoimmune risks. Furthermore, the sucrose selection system is also used to replace traditional selection markers. In terms of codon optimization, researchers improve protein expression levels by altering codon usage while fully considering the host's preference for gene sequence expression. During the optimization process, researchers must also pay attention to codon bias, mRNA secondary structure stability, avoidance of trans-acting elements and restriction enzyme sites, and the balance of GC content.

In summary, the development of novel DNA types and the optimization of DNA have provided new opportunities and challenges for fields such as gene therapy. Yaohai Bio-Pharma has established GMP production platforms for both circular and linearized plasmids. Yaohai also can provide process development and optimization of different types of DNA including these novel types of DNA， fulfilling the different needs of clients.

Yaohai Bio-Pharma is also actively seeking institutional or individual global partners and offers the most competitive compensation in the industry. If you have any questions, please feel free to contact us: [email protected]