Figure 2. Identification of solid lipid nanoparticles-integrin β1 overexpression plasmid (SLNs-pDNA). (A) Gel retardation assay of naked pDNA and SLNs/pDNA complexes with the different mass ratio. (B) Fluorescent microscopy of rat chondrocytes transfected by pDNA (Lipofectamine2000) and SLNs-pDNA. (C) Intracellular distribution assay of SLNs-pDNA in rat chondrocytes. (D) The mRNA and protein levels of integrin β1 in cells treated with SLNs-pDNA using qRT-PCR and western blot assays, respectively.