Hydrolytically Stable Cationic Bis-MPA Dendrimers as Efficient Transfectants for Glioblastoma Cells and Primary Astrocytes

This is the authors' abstract. We don't add key points for this paper.

We report the biological evaluation of bis-MPA dendrimers terminated with either cysteamine (CYS) or 2-(dimethylamino)ethanethiol (DA) groups for siRNA transfection. The results show that aggregation phenomena are critical to the biological performance of these constructs. Confocal and 2D microscopy demonstrated that only the G3-CYS dendrimer transported siRNA into cells. Accordingly, G3-CYS-mediated siRNA transfection reduced intracellular levels of the target proteins─p42-MAPK, Rheb, and MGMT─to 15-25% of control levels in a human glioblastoma cell line and mouse astrocytes. G3-CYS transfection efficiency was similar to that of commercial transfectants. However, its self-degradable bis-MPA backbone and tunable peripheral groups render it markedly superior, making it a promising transfection agent and emphasize the critical balance between structural design, biological efficacy, and safety. Despite its efficacy, G3-CYS displayed a narrow therapeutic window with pronounced cytotoxicity above 1 μM. In vivo studies further confirmed dose-dependent systemic toxicity, likely associated with enhanced blood coagulation.