Triple helix formation of a collagen model peptide induces cell aggregation formation

Biofabrication refers to the creation of tissues and organs from biological materials such as cells and proteins, and is often applied in transplantation therapy and drug efficacy evaluation. For such a construct to function as a tissue, it is important for individual cells to interact closely with each other, so tailor-made approaches for the fabrication of cell aggregates to facilitate intercellular interactions are needed. Some researchers are using the DNA chain as a crosslinking site to make cell-cell assemblies, but DNA degradation and the potential risk of an immune response are concerns. A collagen triple helix is resistant to most proteases and is expected to function as a suitable cell assembling motif in a cell assembly method. Herein, we reported a thermoresponsive cell assembly method driven by triple-helix formation of a collagen model peptide (CMP). We synthesized a 4-armed poly (ethylene glycol) (PEG) terminally co-modified with (proline-proline-glycine)₁₀ ((PPG)₁₀) and deoxycholic acid (DCA) (4-arm-PEG-DCA/-(PPG)₁₀) and evaluated the characteristics and the cell-assembling property. It was found that 4.3 times more cell aggregates were formed after cooling under conditions with 4-arm-PEG-DCA/-(PPG)₁₀ than without 4-arm-PEG-DCA/-(PPG)₁₀. Accordingly, we developed a thermoresponsive cell assembly method driven by triple-helix formation of CMP. The use of CMP is expected to be applied in a new cell assembling approach.