Physicochemical and biological characterization of chitosan-microRNA nanocomplexes for gene delivery to MCF-7 breast cancer cells.
Cancer gene therapy requires the design of non-viral vectors that carry genetic material and selectively deliver it with minimal toxicity. Non-viral vectors based on cationic natural polymers can form electrostatic complexes with negatively-charged polynucleotides such as microRNAs (miRNAs). Here we investigated the physicochemical/biophysical properties of chitosan-hsa-miRNA-145 (CS-miRNA) nanocomplexes and the biological responses of MCF-7 breast cancer cells cultured in vitro. Self-assembled CS-miRNA nanocomplexes were produced with a range of (+/-) charge ratios (from 0.6 to 8) using chitosans with various degrees of acetylation and molecular weight. The Z-average particle diameter of the complexes was <200 nm. The surface charge increased with increasing amount of chitosan. We observed that chitosan induces the base-stacking of miRNA in a concentration dependent manner. Surface plasmon resonance spectroscopy shows that complexes formed by low degree of acetylation chitosans are highly stable, regardless of the molecular weight. We found no evidence that these complexes were cytotoxic towards MCF-7 cells. Furthermore, CS-miRNA nanocomplexes with degree of acetylation 12% and 29% were biologically active, showing successful downregulation of target mRNA expression in MCF-7 cells. Our data, therefore, shows that CS-miRNA complexes offer a promising non-viral platform for breast cancer gene therapy.
Institute of Plant Biology and Biotechnology (IBBP), University of Münster, Schlossgarten 3, D-48149 Münster, Germany.
B
B
Santos-Carballal
Institute of Plant Biology and Biotechnology (IBBP), University of Münster, Schlossgarten 3, D-48149 Münster, Germany.
L J
LJ
Aaldering
Organic and Bioorganic Chemistry, Bielefeld University, Universitätsstrasse 25, D-33615 Bielefeld, Germany.
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M
Ritzefeld
Institute of Plant Biology and Biotechnology (IBBP), University of Münster, Schlossgarten 3, D-48149 Münster, Germany.
S
S
Pereira
Organic and Bioorganic Chemistry, Bielefeld University, Universitätsstrasse 25, D-33615 Bielefeld, Germany.
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N
Sewald
Institute of Plant Biology and Biotechnology (IBBP), University of Münster, Schlossgarten 3, D-48149 Münster, Germany.
B M
BM
Moerschbacher
Department of Gynecology and Obstetrics, University of Münster, Albert-Schweitzer-Campus 1, D-48149 Münster, Germany.
M
M
Götte
Institute of Plant Biology and Biotechnology (IBBP), University of Münster, Schlossgarten 3, D-48149 Münster, Germany.
F M
FM
Goycoolea
D000107:Acetylation; D001943:Breast Neoplasms / Q000378:metabolism / Q000473:pathology; D015815:Cell Adhesion Molecules / Q000235:genetics / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects; D048271:Chitosan / Q000737:chemistry* / Q000633:toxicity; D002942:Circular Dichroism; D005260:Female; D006801:Humans; D061986:MCF-7 Cells; D035683:MicroRNAs / Q000737:chemistry / Q000378:metabolism*; D018613:Microscopy, Confocal; D049329:Nanostructures / Q000737:chemistry*; D010316:Particle Size; D011956:Receptors, Cell Surface / Q000235:genetics / Q000378:metabolism; D020349:Surface Plasmon Resonance; D014162:Transfection
D015815:Cell Adhesion Molecules; C407243:F11R protein, human; C541010:MIRN145 microRNA, human; D035683:MicroRNAs; D011956:Receptors, Cell Surface; D048271:Chitosan