微小RNA纳米递送体系的构建及其研究进展

MicroRNA (miRNA) is a class of small regulatory noncoding RNA (approximately 21-25 bases) endogenously expressed in animals, plants and pathogenic microorganisms. It has the function at the translation level as an important gene expression regulator. Until now, more than 1 000 miRNAs have been identified in organisms, which could regulate around 30% of human genes. MiRNA also plays a key role in cell growth, differentiation and apoptosis. More importantly, studies demonstrate that the expression of miRNAs in organisms is tightly associated with neurological disorders, cardiovascular diseases, cancer and viral infections. Therefore, miRNA has been widely used for early diagnosis, prognostic evaluation and therapeutic targets of many diseases. Regulating expression of miRNA by RNA interference technology in organisms has attracted more and more attention. By delivering miRNA or "antisense" nucleotides to cells, the expression level of target miRNA can be regulated, so as to achieve the treatment of diseases caused by gene disorders. Currently, miRNA-based therapeutics have shown great potential in cancer, emerging infectious diseases and other diseases. However, the characteristics of nucleotide chains, such as negativity and degradability, make it difficult for nucleotide chains to cross cell membranes into cells. Therefore, the rational design of delivery vectors is of great significance for improving the delivery and efficiency of therapeutic genes. Until now, it has been reported that a variety of materials can be used as gene carriers for intracellular delivery of miRNA. Liposome capsules can enter the cell through endocytosis, which are prepared by encapsulating drug molecules in vesicles formed by phospholipid bilayer membranes. In addition, using the physical and chemical properties of different materials, various forms of nanocarriers, such as polymer nanoparticles, organic and inorganic nanoparticles, have been successfully developed and designed, which can achieve targeted delivery of gene drugs and intelligent stimulus release. In this review, we will discuss the function of intracellular miRNA and the methods of regulating the expression of miRNA, summarize the progress of nanocarriers in delivering miRNA therapeutic genes, and analyze the design ideas, methods and mechanisms of nanocarriers systems. In addition, according to the current research progress, we will discuss the development direction of miRNA-based therapy in emerging areas, in order to provide reference for the preparation of new intelligent gene delivery system.