“Click” Nucleic Acids (CNAs) are a novel family of modified nucleic acids that are quickly and easily oligomerized via thiol-ene click chemistry, meanwhile retaining the ability to recognize and hybridize with complementary nucleic acid sequences. Like DNA hybridization, CNA hybridization can be a useful phenomenon capable of creating complex secondary structures, such as programmable, stimuli-responsive three-dimensional polymeric gel networks. This work aims to develop and characterize a novel, responsive hybrid polymeric gel crosslinked by a CNA hybridization. Thymine CNA monomer was copolymerized with an eight arm poly(ethylene glycol) (8PEG) (with a molecular weight of 20 kDa) to create hybrid 8PEG-T macromolecules (Figure 1A). The 8PEG-T was dissolved in mixtures of DMSO and H<sub>2</sub>O, and upon adding a complementary 40-mer of adenine DNA as a crosslinker, soft gels formed with shear moduli on the order of 100 Pa to 1 kPa depending on the concentration and amount of crosslinker present (Figure 1B). In addition, no gel formed when a 40-mer of thymine DNA was added to the solution. Oscillatory frequency sweeps of these gels at room temperature showed some frequency dependence, with potential crossover points at frequencies lower than 10<sup>-1</sup> rad/s, indicating a long lifetime of the CNA-DNA hybrid. Furthermore, these gels were found to be thermally reversible (Figure 1C), with reverse gelation temperatures as high as 60°C in some cases, supporting the observation of a strong CNA-DNA interaction. Overall, this work supports the idea that CNA hybridization can support complex 3D networks with properties that would be expected from hydrogen bonded materials.

Hybrid polymeric gel networks crosslinked via “click” nucleic acid hybridization

2019 Fall National Meeting

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.