[Research progress of coarse-grained molecular dynamics in drug carrier materials].

As one of the traditional computer simulation techniques, molecular simulation can intuitively display and quantify molecular structure and explain experimental phenomena from the microscopic molecular level. When the simulation system increases, the amount of calculation will also increase, which will cause a great burden on the simulation system. Coarse-grained molecular dynamics is a method of mesoscopic molecular simulation, which can simplify the molecular structure and improve computational efficiency, as a result, coarse-grained molecular dynamics is often used when simulating macromolecular systems such as drug carrier materials. In this article, we reviewed the recent research results of using coarse-grained molecular dynamics to simulate drug carriers, in order to provide a reference for future pharmaceutical preparation research and accelerate the entry of drug research into the era of precision drug design.

Study on a novel enzymatic colon-targeted particle of total saponins of Pulsatilla by mechanical grinding technology in a solvent free system.

Oral colon-targeting preparation can achieve targeted drug release in the lesion site and have a great application prospect. In this study, we presented the principle of particle design in the field of materials science into the preparation of colon-targeting preparation. Enzymatic Pulsatilla saponins Colon-targeting composite Microparticles (EPCM) were prepared by mechanical grinding without any organic solvent. Firstly, Response Surface Methodology (RSM) designed by Box-Behnken was used to optimize the preparation process of EPCM, and the structure of EPCM was characterized. All-Atomic and Molecular Dynamics (AAMD) was used to calculate the compatibility between drugs and coating materials before and after release, so as to explain the principle of colon- targeted drug release in this method. Then, colon-targeting characteristics of EPCM in vitro and in vivo were investigated by experiments. Finally, the pharmacodynamics effects of this composite microparticles on Ulcerative Colitis (UC) induced by DSS in C57BL/6 mice were evaluated. The results demonstrated that the colon-targeting composite microparticles could be prepared by mechanical grinding based on particle design principle. The composite microparticles have appropriate colon-targeting drug release performance in vitro and in vivo, and have good anti-ulcerative colitis effect. This study provides a new idea for the preparation of oral colon-targeting preparation of Traditional Chinese medicine, and has evident reference value for the study of coating isolation and powder modification of traditional Chinese medicine for other purposes.