(364d) Preparation of Biomolecule-Responsive Gels by Biomolecular Imprinting

Stimuli-responsive gels that undergo volume changes in response to environmental changes such as pH and temperature are promising smart material candidates for novel drug delivery systems and sensors in biochemical and biomedical fields. Recently, several researchers have focused on biologically stimuli-responsive gels that can sense specific signal biomolecules, such as glucose and protein: signal biomolecule-responsive gels have become increasingly important as smart devices for drug delivery systems and molecular diagnostics. Molecular imprinting is a promising method to create synthetic hosts having molecular recognition sites. In this paper, we reveal that proteins and DNAs can be used as ligands in molecular imprinting and that using minute amounts of cross-linker enables resultant gels to undergo volume changes in response to target biomolecules. In this study, the biomolecule-responsive gels that exhibited volume changes in response to a tumor-specific marker glycoprotein and a target DNA were prepared by biomolecular imprinting using protein and DNA as ligands. We report dynamic biomolecule recognition of glycoprotein-imprinted gels having lectin and antibody molecules as ligands for a target tumor marker glycoprotein and DNA-imprinted gels having DNAs as ligands for a target DNA. This paper focuses on biomolecule-responsive behavior of the biomolecule-imprinted gels prepared with minute amounts of cross-linker. The glycoprotein-imprinted gel shrank in response to a target tumor marker glycoprotein but nonimprinted gel swelled a little. The glycoprotein-responsive shrinking of the imprinted gel was due to formation of lectin-glycoprotein-antibody complexes that acted as reversible cross-linking points. Glycoprotein-imprinted gels only shrank when both lectin and antibody in the gels simultaneously recognized the saccharide and peptide chains of the target glycoprotein. Furthermore, biomolecular imprinting using single strand DNAs as ligands enabled us to prepare DNA-responsive gels that undergo volume changes in response to a target DNA. The swelling ratio of DNA-imprinted gels was strongly dependent upon the sequence of DNA in a buffer solution. As shrinking behavior of biomolecule-imprinted gels in response to target biomolecules enables the accurate detection and recognition of tumor marker glycoproteins and DNAs, they have many potential applications as smart devices in sensing systems and as molecular diagnostics. This paper focuses on synthetic strategy of biomolecule-imprinted gels and their responsive behavior.