Influence of palygorskite on the structure and thermal stability of collagen

We investigated the influence of palygorskite on the conformation and thermal stability of type I collagen. Fluorescence spectroscopy and Fourier transform infrared spectroscopy (FTIR) studies demonstrated that the interaction between collagen and purified palygorskite (PAL) led to the contraction and aggregation of collagen molecules, but did not destroy the triple helix backbone of collagen. Due to the structure of collagen and PAL, the interaction mainly involved hydrogen bonding and electrostatic forces. Atomic force microscopy (AFM) observations clearly displayed the nanorod morphology of PAL, and further revealed the fibril aggregation of collagen in the presence of PAL. Differential scanning calorimetry (DSC) measurements indicated that the PAL-collagen nanocomposites improved the thermal stability in comparison with pure collagen. The present study showed that PAL could modify collagen as a reinforcing agent and preserve the triple helix structure of collagen.