Toward Bioactive Hydrogels: A Tunable Approach via Nucleic Acid-Collagen Complexation

Area of Science:

• Biomaterials Science
• Biochemistry
• Materials Engineering

Background:

• Nucleic acid-collagen complexes (NACCs) are biomaterials formed by binding single-stranded DNA (ssDNA) with type I collagen.
• These complexes self-assemble into microfibers and nanoparticles, showing potential in tissue engineering and regenerative medicine.
• The precise mechanisms of nucleic acid-driven collagen assembly and their impact on material properties require further elucidation.

Purpose of the Study:

• To investigate the relationship between the microscopic structure of NACCs and their bulk material properties.
• To demonstrate that NACCs can be engineered as mechanically tunable systems by controlling collagen-DNA interactions.
• To understand how varying ratios of collagen to ssDNA influence NACC formation and properties.

Main Methods:

• Characterization of NACCs using varying molar ratios of collagen to random ssDNA oligonucleotides.
• Assessment of molecular interactions via infrared spectroscopy.
• Evaluation of gelation and rheological behavior.
• Microscopic analysis using phase contrast, confocal reflectance, and transmission electron microscopy to determine 3D structural organization.

Main Results:

• DNA oligonucleotides significantly reinforce and rearrange the collagen hydrogel network.
• DNA addition accelerates gelation by promoting rapid fiber formation and spontaneous self-assembly.
• The elasticity of NACC hydrogels is tunable based on the collagen-to-DNA molar ratio, ssDNA length, and collagen type.

Conclusions:

• The study demonstrates the successful engineering of mechanically tunable DNA-based hydrogel systems.
• Tailoring DNA content and collagen concentration allows for precise control over hydrogel stiffness.
• These findings offer new possibilities for developing advanced bioactive hydrogels for diverse biomedical applications.