In situ self imine-crosslinked nanocomplexes loaded with small noncoding RNA for efficient osteoarthritis attenuation

Abstract

Small noncoding RNA molecules which can help to recover cartilage homeostasis exhibit great potential in OA alleviation. However, effective small RNA transfection to target cells dwelled in cartilage tissue is quite a challenging work because of the inhibition of dense and anion cartilage matrix as well as the limited RNA transmembrane ability. In this study, we developed an in-situ imine crosslinking nanocomplexes (PAR) formed by polyethyleneimine (PEI), aldehyde group modified hyaluronic acid (AHA), and small noncoding RNA (miR-140). Our in vitro study showed that covalently crosslinked and positively charged PAR nanocomplexes could effectively load and transfect miR-140 to chondrocytes and further exert chondrocyte protection under IL-1β induction even in the strong and persistent interference of HA and chondroitin sulfate (CS), which are widely distributing anion biomacromolecules in cartilage matrix or articular cavity. And in vivo evaluation showed that PAR could alleviate OA progression in mice effectively. However, non-crosslinked positively charged nanocomplexes failed in miR-140 transfection both in HA and CS interference condition and finally failed in in vivo OA attenuation in mice model. This study not only provides an effective, simple, and low-cost delivery vehicle for small noncoding RNA based therapy in OA but also demonstrates that covalent crosslinking in positively charged vehicles is quite necessary for the design of RNA transfection materials to cartilage because of the strong and persistent impact of anion biomacromolecules (HA and CS) that distribute widely in cartilage matrix on the stability of RNA loading carriers.