DNA Meets Synthetic Polymers – Highly Versatile Hybrid Materials
|
Artwork of two type of micelles engineered by different ssDNAs
|
-
Combining synthetic strategies from Organic and Polymer Chemistry with methods from Molecular Biology
-
Exploring the interactions of bioorganic hybrid materials with living systems for biomedicine
Our group has prepared biological organic hybrid structures consisting of DNA and synthetic polymers. Different synthetic strategies for the generation of linear, single stranded (ss) and double stranded (ds) DNA block copolymers were developed. DNA-polyethylenglycol- and DNA-poly-N-isopropylacrylamid diblock copolymers were synthesized by a grafting onto approach in solution. In contrast, DNA-polypropyleneoxide diblock copolymers were fabricated by a grafting onto strategy on the solid phase in a fully automated fashion using a DNA-synthesizer.
Beside the preparation of DNA block copolymers with a relative short DNA-segment, we also demonstrated how these bioorganic polymers can be synthesized exhibiting large DNA blocks (>1000 bases) applying the polymerase chain reaction (PCR), a method that is usually employed in Molecular Biology and for diagnostic testing.
Amphiphilic DNA block copolymers self-assemble into micelle aggregates. Special attention was paid to engineering the structural properties of these nanoparticles (Fig. 1).1 Thereby spherical nanoobjects were transformed into rod-like aggregates by a simple hybridization procedure.
|
Figure 1: a) Hybridization of ss DNA block copolymer micelles with short complementary oligonucleotides does not change the spherical shapes of the particles. b) Watson-Crick base pairing with long template strands encoding several times the complement of the micelles leads to formation of rod-like particles.
|
In the context of applications regarding DNA block copolymers, programmable, sequence specific organic reactions in spherical micelles were performed2 and these nanobjects were successfully employed for drug delivery of anticancer drugs (Fig. 2).3 Due to the ease of functionalization of the nanosized particles by hybridization a combinatorial platform for testing drug delivery vehicles was established.
|
Figure 2: a) Functionalization of ss DNA block copolymer micelles with targeting units for cancerous cells by hybridization. b) Loading of the particles with an anticancer drug that accumulates in the hydrophobic core of the micelles.
|
_______________________
(1) Ding K.; Alemdaroglu, F. E.; Börsch, M.; Berger, R.; Herrmann, A.; Angew. Chem. Int. Ed.
2007, 47, 1172-1175.
(2) Alemdaroglu, F. E.; Ding, K.; Berger, R.; Herrmann, A. Angew. Chem. Int. Ed. 2006, 45, 4206-4210.
(3)
Alemdaroglu FE, Alemdaroglu CN, Langguth P, HerrmannA;
Adv. Mat.
2008, 20: 899-902.
| Last modified: | November 28, 2011 16:48 |
