Xiaojun Cai,Haiqing Dong,Junping Ma,Haiyan Zhu,Wei Wu,Meng Chu,Yongyong Li,Donglu Shi
A spatial effect of targeted signal distribution is found in catiomer–gene polyplexes which strongly influences the gene transfection profiles. The nuclear localization sequence PKKKRKV (NLS) is chosen as the target ligand. For a given gene delivery system of constant composition, size, and charge, it is engineered such that the NLS is the only structural variable in polyplexes. This unique architecture of polyplexes relies on successive electrostatic interaction. The structural features of the PKKKRKV sequence in polyplexes are investigated by NMR. The gene transfection profiles of the polyplexes are found to be well correlated with the spatial distribution of the nuclear localization sequence. Upon modification of nuclear localization, the gene transfection efficiency is found to increase remarkably from 40% to 60%. The drastic improvement of gene transfection is explained by a NLS spatial distribution mechanism. High gene transfection based on spatial NLS distribution provides a new base for the design and development of non-viral gene delivery vectors.
Guoxin Tan,Dandan Liu,Renfang Zhu,Hao Pan,Jiayang Li,Weisan Pan
Retinal diseases, including age-related macular degeneration (AMD), are a major cause of blindness. Efficient delivery of therapeutic genes to retinal cells to treat retinal disease is a formidable challenge. In this study, we developed a core-shell nanoplatform composed of a core and two external layers for targeted delivery of the gene to the retina. The inner core was composed of amino acid-functionalized dendrimers and a nuclear localization signal (NLS) for DNA complexation, nuclear transport and efficient transfection. The inner core was coated in a lipid bilayer that comprised pH-sensitive lipids as the inner shell layer. Hyaluronic acid (HA)-1,2-dioleoylphosphatidylethanolamine (DOPE) as the outermost shell layer was used for retinal cell targeting. This core-shell nanoplatform was developed so that the mobility in the vitreous body of these negatively charged carriers would not be affected by their surface charge, allowing diffusion into the retina, uptake into the retinal cells via CD44-mediated internalization , and finally transport into the nucleus by the NLS. The designed nanoparticles showed safety both in vitro and in vivo and inhibited the expression of VEGF under hypoxia-mimicking conditions. In vitro angiogenesis assays exhibited significant inhibitory effects on cell migration and tube formation. The in vivo assays indicated that this nanoplatform could be delivered to the retina. Taken together, this nanoplatform has the potential to transfer gene material into the retina for the treatment of retinal diseases, including AMD. Statement of significance It remains a challenge to develop an efficient nonviral vector for gene therapy, especially retinal gene therapy. Various barriers exist in gene delivery and the unique ocular environment, making gene delivery to the retina difficult. In this study, we designed a negatively charged core-shell nanoplatform (HD-NP PND ) for the targeted delivery of gene to the retina. The developed nanoplatform possessed excellent transfection efficiency and safety both in vitro and in vivo. It efficiently delivered a gene to the retina. The results of this study suggested that this core-shell nanoplatform has the potential to deliver genes to the retina to treat retinal diseases, including age-related macular degeneration (AMD).
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