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This study explores the application pathways of cationic amphiphilic calixarenes in gene delivery, focusing on nanoscopic micelle formation. Results from gene transfection experiments using multicalixarenes are discussed, along with their effectiveness in mediating gene expression. The research delves into the synthesis of tetracationic calixarenes and their water solubility, highlighting the formation of micelles in solution. Findings suggest a potential approach for generating small DNA nanoparticles efficiently, paving the way for advancements in gene delivery methods.
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Cationic amphiphilic calixarenes: nanoscopic micelle formation and gene delivery Roman Rodik, Stanislav Miroshnichenko, Vitaly Kalchenko Institute of Organic Chemistry National Academy of Sciences of Ukraine Namrata Jain, Ludovic Richert, Yves Mely, Andrey Klymchenko Laboratory of Biophotonics and Pharmacology, Faculty of Pharmacy, University of Strasbourg
Application pathways of calixarenes in biology and medicine Picture from: Calixarene-based multivalent ligands. L. Baldini, A. Casnati, F. Sansone and R. UngaroChem. Soc. Rev., 2007, 36, 254–266
Calixresorc[4]arene glycoclusters. DNA binding and transfection Y. Aoyama, Trend. Glycosci. Glycotech. 2005, 17, 39-47.
Gen transfection by polycationic multicalixarenes with ammonium residues Results of transfection pDs2-mito (Clontech) plasmid in CHO cells a FuGene®; b control; ccone multicalixarene; d1,3-alt multicalixarene R. Lalor, J. L. DiGesso, A. Mueller and S. E. Matthews, Chem. Commun. 2007, 4907.
Gen transfection by tetraguanidinium calixarenes Results of transfection pEGFP-C1 plasmid in RD-4 cells mediated by calixarene-DOPE formulation V. Bagnacani, F. Sansone, G. Donofrio,L. Baldini,A. Casnati,R. Ungaro.Org. Lett., 2008, 10, 3953-3956.
Water soluble tetracationic calix[4]arene CX3 For tetrapropoxy calix[4]arene CX3 size of aggregates near 3 nm (DLS data) n = 6 N. O. Mchedlov-Petrossyan, L. N. Vilkova, N. A. Vodolazkaya, A. G. Yakubovskaya, R. V. Rodik, V. I. Boyko and V. I. Kalchenko, Sensors 2006, 6, 962. N. O. Mchedlov-Petrossyan, N. A. Vodolazkaya, L. N. Vilkova, O. Y. Soboleva, L. V. Kutuzova, R. V. Rodik, S. I. Miroshnichenko and A. B. Drapaylo, J. Mol. Liq. 2009, 145, 197.
Synthesis of tetracationic tetraoctylcalix[4]arenes CX8 CX8im 1 Water solubility of CX8 and CX8im – high!!!
Pyren fluorescence in CX8 water solution I1 I3 Slow then sharp growth of fluorescence as well as changes in I1/I3 relation indicates that micelles arises in solution
CMC values obtained with pyren probe CX3 CX8 CX8im
Size of micelles (Data obtained from DLS measurements) CX3 CX8 CX8im Concentration of CX3 10-3 M, CX8, CX8im 10-4 M 1N. O. Mchedlov-Petrossyan, N. A. Vodolazkaya, L. N. Vilkova, O. Y. Soboleva, L. V. Kutuzova, R. V. Rodik, S. I. Miroshnichenko and A. B. Drapaylo, J. Mol. Liq. 2009, 145, 197.
Fluorescence correlation spectroscopy experiments FCS data on CX8 micelles stained with Nile Red
Aggregation number of CX8 in micelles Geometrical estimation: CX8 approximately is truncated cone with D 1.53 nm, d 0.51 nm and h 1.62 nm. For micelle formation necessary regular cone geometry with l 2.54 nm. So diameter of micelles 5.1 nm Volume of micelle 69.5 nm3, volume of CX8 (total cone) 1.5 nm3, void volume at hexagonal packing near 10%. So the aggregation number (69.5×0.9)/1.5 is 41.7. FCS Data: 50 particles per excitation volume 0.34×10-15 L Obtained concentration ca 250 nM. Starting concentration 10 µM. Aggregation number 10 µM/250 nM is 40
CT-DNA complexation Ethidium Bromide displacement experiments Dependence of integral intensity EB at different concentration of cationic calixarenes Normalized graphs Tris-bufer 20mM, pH 7.4 [CT-DNA]=2•10-5 M Tris-bufer 20mM, pH 7.4, 150mM NaCl [CT-DNA]=2•10-5 M
Size of DNA-calixarene micelles (Data obtained from DLS measurements)
AFM image of CT-DNA-calixarene complexes V(CX8) 1.5(0.4)105 nm3 V(CX8im) 0.9(0.3)105 nm3 d(CX8) 65nm d(CX8im) 55 nm AFM topography (A and C) and phase (B and D) images of calixarene CX8 (A,B) and CX8im (C,D) complexes with CT-DNA (N/P = 2) in 20 mM MES buffer (pH 7). Tapping mode in buffer was used. Circles highlight some larger structures showing, which in phase images can be resolved as combination of smaller particles.
DNA-calixarene micelles analysis (CT-DNA was used) One DNA-CX8 micelle contains 700 CX8 micelles
Gene transfection Transfection is the process of deliberately introducing nucleic acids into cells. The term is used notably for non-viral methods in eukaryotic cells. A plasmid (lat. plasmid) is a DNA molecule that is separate from, and can replicate independently of, the chromosomal DNA. They are double stranded and, in many cases, circular. Plasmids usually occur naturally in bacteria, but are sometimes found in eukaryotic organisms Protein biosynthesis Transcription ► Processing and Transport ► Translation
Results of pCMV-Luc plasmid transfection mediated by calixarenes and calixarene-DOPE formulations Semi-quantitative analyses, amount of transfected cell in the view area Transfection efficiency of calixarene/pDNA complexes in COS-7 cells. Gene expression determined from the luciferase assay was expressed as RLU/mg of total protein. The experiments were repeated three times.
Viability of cells MTT cell viability assay For transfection experiments were used solutions of 10 and 25 µM calixarene concentration
Conclusions and perspectives •The present results propose a powerful two-step hierarchical approach for generating small DNA nanoparticles. •The further development of gene delivery vectors based on calixarenes capable to form stable cationic micellar structures may discover more powerful or selective DNA vectors for needs biology and medicine.
Acknowledgements: Rodik Roman is grateful to ARCUS program (collaboration of Ukraine, Russia and region Alsace, France) for supporting his visit to the French Laboratory.
Plasmid binding Gel electrophoresis experiments CX3 CX8 CX8im
Results of GFP plasmid transfection mediated by calixarenes and calixarene-DOPE formulations Semi-quantitative analyses, amount of transfected cell in the view area Transfection efficiency of calixarene/pDNA complexes in COS-7 cells. Gene expression was determined from the count of green fluorescence cells in the quarter of microscope view area.