RESUMEN
We have previously developed a novel adenovirus vector (Adv) that targeted tumor tissues/vasculatures after systemic administration. The surface of this Adv is conjugated with CGKRK tumor homing peptide by the cross-linking reaction of polyethyleneglycol (PEG). In this study, we showed that the condition of PEG modification was important to minimize the gene expression in normal tissues after systemic treatment. When Adv was modified only with PEG-linked CGKRK, its luciferase expression was enhanced even in the liver tissue, as well as the tumor tissue. However, in the reaction with the mixture of non-cross-linking PEG and PEG-linked CGKRK, we found out that the best modification could suppress its gene expression in the liver, without losing that in the tumor. We also studied the internalization mechanisms of CGKRK-conjugated Adv. Results suggested that there is a specific interaction of the CGKRK peptide with a receptor at the cell surface enabling efficient internalization of CGKRK-conjugated Adv. The presence of cell-surface heparan sulfate is important receptor for the cellular binding and uptake of CGKRK-conjugated Adv. Moreover, macropinocytosis-mediated endocytosis is also important in endocytosis of CGKRK-conjugated Adv, aside from clathrin-mediated and caveolae-mediated endocytosis. These results could help evaluate the potentiality of CGKRK-conjugated Adv as a prototype vector with suitable efficacy and safety for systemic cancer gene therapy.
Asunto(s)
Adenoviridae/genética , Reactivos de Enlaces Cruzados/química , Terapia Genética , Neoplasias/terapia , Fragmentos de Péptidos/química , Polietilenglicoles/química , Adenoviridae/química , Secuencia de Aminoácidos , Animales , Línea Celular Tumoral , Endocitosis , Femenino , Genes Reporteros , Vectores Genéticos , Hígado/metabolismo , Luciferasas de Luciérnaga/biosíntesis , Luciferasas de Luciérnaga/genética , Pulmón/metabolismo , Ratones , Ratones Endogámicos C57BL , Trasplante de Neoplasias , Bazo/metabolismo , Transducción Genética , TransgenesRESUMEN
A dendritic cell (DC) networking system has become an attractive approach in cancer immunotherapy. Successful DC gene engineering depends on the development of transgene vectors. A cationic polymer, chitosan-linked polyethylenimine (PEI) (CP), possessing the advantages of both PEI and chitosan, has been applied in nonviral transfection of DCs. Physicochemical evaluation showed that CP/DNA complexes could form cationic nanoparticles. Compared with DCs transfected with commercial reagent, Lipofectamine2000, it showed higher transfection efficiency and lower cytotoxicity when DCs were transfected with CP/DNA complexes. A nuclear trafficking observation of CP/DNA complexes by a confocal laser scanning microscope further revealed that the CP could help DNA enter into the cytoplasm and finally into the nucleus of a DC. Finally, vaccination of DCs transfected with CP/DNA encoding gp100 slightly improved resistance to the B16BL6 melanoma challenge. This is the first report that CP polymer is used as a nonviral vector for DC gene delivery and DC vaccine. Essentially, these results might be helpful to design a promising nonviral vector for DC gene delivery.
Asunto(s)
Quitosano/química , Células Dendríticas/metabolismo , Portadores de Fármacos/química , Polietileneimina/química , Transfección/métodos , Animales , Antígenos de Neoplasias/metabolismo , Supervivencia Celular/efectos de los fármacos , ADN/genética , ADN/metabolismo , Células Dendríticas/inmunología , Portadores de Fármacos/toxicidad , Vectores Genéticos/genética , Masculino , Melanoma Experimental/inmunología , Ratones , Ratones Endogámicos C57BL , Plásmidos/genética , Vacunas de ADN/genética , Vacunas de ADN/inmunologíaRESUMEN
Dynamic covalent bonds supplied by reversible anthracene dimerization were combined with pillar[5]arene/imidazole host-guest interactions to construct double-dynamic polymers. Heating such polymers (in solution or as a gel) led to depolymerization by dissociation of either the host-guest complexes alone or the complexes and the anthracene dimers, depending on the extent of heating. The polymers reformed readily upon cooling or irradiation.
Asunto(s)
Antracenos/química , Polímeros/síntesis química , Termodinámica , Ciclización , Dimerización , Estructura Molecular , Procesos Fotoquímicos , Polímeros/químicaRESUMEN
OBJECTIVE: To investigate the method for mandible osteotomy in order to make the mandible of various square face appear harmony. METHODS: According to different types of the mandible, mandible angle osteotomy was performed in combination with mandible edge, mandible half ring osteotomy or chin augmentation. RESULTS: A total of 312 cases have been treated since 1996. In this series, mandible angle and mandible edge osteotomy was performed in 200 cases; only mandible edge osteotomy in 23; mandible half ring osteotomy in 15, chin sharpening in 9, chin augmentation with autogenous bone implantation, in 32. Postoperative follow-up of 150 cases for 1-12 months showed that the satisfactory rate was 97%. CONCLUSION: Integrated mandible osteotomy can make the square face look natural and nice-looking.