Comb-Like Amphiphilic Polycarbonates with Different Lengths of Cationic Branches for Enhanced siRNA Delivery.
Dong Y , Zhou J , Wang C , Wang Y , Deng L , Zhang J , Dong A
Owing to the biodegradability and good biocompatibility polycarbonates show the versatile class of applications in biomedical fields. While their poor functional ability seriously limited the development of functional polycarbonates. Herein, a new Br-containing cyclic carbonate (MTC-Br) and a polycarbonate atom transfer radical polymerization (ATRP) macro-initiator (PEG-PMTC-Br) is synthesized. Then, by initiating the side-chain ATRP of 2-(dimethyl amino)ethyl methacrylate (DMAEMA) on PEG-PMTC-Br, a series of comb-like amphiphilic cationic polycarbonates, PEG-b-(PMTC-g-PDMAEMA) (GMDMs), with different lengths of cationic branches are successfully prepared. All these poly(ethylene glycol)-b-(poly((5-methyl-2-oxo-1,3-dioxane-5-yl) methyl 2-bromo-2-methylpropanoate/1,3-dioxane-2-one)-g-poly(2-dimethyl aminoethyl methacrylate) (GMDMs) self-assembled nanoparticles (NPs) (≈180 nm, +40 mV) can well bind siRNA to form GMDM/siRNA NPs. The gene silence efficiency of GMDM/siRNA high to 80%, which is even higher than the commercial transfection reagent lipo2000 (76%). But GMDM/siRNA shows lower cell uptake than lipo2000. So, the high gene silence ability of GMDM/siRNA NPs can be attributed to the strong intracellular siRNA trafficking capacity. Therefore, GMDM NPs are potential siRNA vectors and the successful preparation of comb-like polycarbonates also provides a facile way for diverse side-chain functional polycarbonates, expanding the application of polycarbonates.
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