Research

Research questions. How do nanocarriers recognize, bind to, and cross cell membranes? How do surface modification, targeting ligands, and nonspecific interactions affect delivery efficiency? We investigate how the behavior of nanomedicines at biological interfaces relates to their therapeutic function.

Our approach. We combine single-molecule force spectroscopy, single-particle force tracing, and biological imaging to measure binding forces and track endocytosis at the level of individual particles. We design peptide micelles, virus-like particles, nucleic acid nanostructures, and cell membrane-coated carriers to investigate drug loading, transmembrane transport, intracellular release, and nucleic acid delivery. In tumor models, we explore combinations of chemotherapy, phototherapy, gas therapy, gene silencing, and immunomodulation. We also develop antibacterial systems assisted by nucleic acid nanostructures and evaluate their performance in cell and animal models.

Research questions. How does mechanical force change molecular conformations, regulate interactions, and drive chemical reactions? How do anchoring structures at molecular–metal interfaces, ions, and local environments affect load transfer, failure, and reversibility? We seek to connect the behavior of individual molecules under force with macroscopic material properties.

Our approach. We use single-molecule force spectroscopy and theoretical calculations to study mechanophore activation, bond scission, and subsequent reactions, and to develop anchoring strategies that improve interfacial stability. We examine conformations and binding states under force in systems governed by host–guest recognition, coordination, and hydrogen bonding. By incorporating functional units such as crown ethers into polymers, we regulate energy dissipation and combine molecular measurements with macroscopic mechanical testing to develop supramolecular materials with high strength, toughness, and responsiveness to stimuli.

Research questions. How do chain chemistry, chain folding, molecular packing, and connectivity in amorphous regions jointly determine polymer mechanics? How does the motion of individual chains in crystalline and amorphous networks contribute to stress transfer and macroscopic deformation, including fiber yielding?

Our approach. We use AFM and single-molecule force spectroscopy to investigate chain mechanics in single crystals, spherulites, and fibers across crystalline, semicrystalline, and amorphous polymers. Pulling individual chains from single crystals allows us to probe chain folding, force-induced melting, sliding, and relaxation, and to assess the effects of conformation, crystal thickness, crystal form, and temperature. We also study chain migration, long-range correlations in chain motion, and load bearing by tie chains, combining nanomechanical measurements with macroscopic tensile tests to connect single-chain structure with material properties.

Research questions. AFM force spectroscopy primarily measures force and distance. How can we also obtain information on molecular structure, chemical change, and particle position during force application? We focus on correlating and synchronizing complementary signals at the single-molecule and single-particle levels.

Our approach. We combine AFM with infrared spectroscopy to develop a single-molecule force spectroscopy–infrared spectroscopy (SMFS–IR) system that couples optical modulation with force detection. Together with single-molecule force measurements in air, this approach enables correlated detection and assignment of mechanical and chemical signals during polymer mechanochemistry at the single-molecule level. We also develop integrated AFM–total internal reflection fluorescence microscopy (AFM–TIRF) for single-particle fluorescence imaging and spectroscopy, and use nanoscale chemical imaging to investigate phase separation in polymer materials.