Shenzhen Moore Vaporization Health & Medical Tech Co., Ltd.

Hyaluronic acid (HA) is a typical non-Newtonian fluid possessing unique shear-thinning properties, which make it highly valuable in biomedical fields such as tissue engineering and drug delivery. However, existing research has primarily focused on characterizing macroscopic rheological behavior, with limited systematic analysis of the dynamic response mechanisms of microscopic hydrogen bond networks during shear deformation. To better explain the shear thinning properties of hyaluronic acid solutions at the microscopic level, this study employed molecular dynamics simulation methods and abstracted the rotational shear from macro-scale rheological experiments into linear shear.

A system composed of hyaluronic acid molecules and water molecules was used to simulate the conformational evolution of hyaluronic acid solutions under different shear rates. This study analyzed the number of hydrogen bonds formed between hyaluronic acid molecules and water molecules, hydrogen bond lengths, as well as hydrogen bond angles. Additionally, these findings were combined with macroscopic rheological experiments.

The number of hydrogen bonds formed between hyaluronic acid molecules and water molecules decreased under shear stress. Furthermore, the hydrogen bond lengths increased, and the hydrogen bond angles decreased, resulting in an overall weakening of hydrogen bond strength.

The loss of hydrogen bond strength directly reduces fluid resistance and enhances solution flowability, which is consistent with the shear thinning characteristics observed in macroscopic rheological experiments.