PLK1 and brain neoplasm: (xvi) Intravenously injected, thin disulfide-cross-linked polymeric shell nanocapsules decorated with angiopep-2 peptide and encapsulating Cas9 RNP (approximately 30 nm in diameter) achieved high PLK1 gene editing efficiency in brain tumors, reaching up to 38.1% in orthotopic CSC2-Luc GSC tumor-bearing mice [56].