To induce fibril formation, the solution was incubated at 75 C and stirred at 550 rpm for 65 h. Subsequently, furfurylamine modified fibril was prepared by using the amidation reaction following the protocol according to Cai et al. In a typical experiment, DMTMM (1.4 g) was added into the fibril suspension (2.0%, w/v, 50 mL) and kept stirring for 20 min to fully activate the carboxyl groups of fibril. Then, furfurylamine (0.75 g) was added dropwise to the suspension. This reaction was maintained at room temperature for 24 h under continuous stirring. Afterwards, furanfibril was cross-linked using (MAL)4-PEG via D-A click chemistry. In a representative example, an appropriate amount of (MAL)4-PEG was added into the furan-fibril suspension and allowed to react overnight at room temperature to give the fibril clusters.