Assessing the structural stability and drug encapsulation efficiency of poly(ethylene glycol)-poly(L-lactic acid) nanoparticles loaded with atorvastatin calcium: Based on dissipative particle dynamics.

Block polymer micelles have been proven highly biocompatible and effective in improving drug utilization for delivering atorvastatin calcium. Therefore, it is of great significance to measure the stability of drug-loading nano micelles from the perspective of block polymer molecular sequence design, which would provide theoretical guidance for subsequent clinical applications. This study aims to investigate the structural stability of drug-loading micelles formed by two diblock/triblock polymers with various block sequences through coarse-grained dissipative particle dynamics (DPD) simulations. From the perspectives of the binding strength of poly(L-lactic acid) (PLLA) and polyethylene glycol (PEG) in nanoparticles, hydrophilic bead surface coverage, and the morphological alteration of nanoparticles induced by shear force, the ratio of hydrophilic/hydrophobic sequence length has been observed to affect the stability of nanoparticles. We have found that for diblock polymers, PEG3kda-PLLA2kda has the best stability (corresponding hydrophilic coverage ratio is 0.832), while PEG4kda-PLLA5kda has the worst (coverage ratio 0.578). For triblock polymers, PEG4kda-PLLA2kda-PEG4kda has the best stability (0.838), while PEG4kda-PLLA5kda-PEG4kda possesses the worst performance (0.731), and the average performance on stability is better than nanoparticles composed of diblock polymers.

Advances in self-assembling of pH-sensitive polymers: A mini review on dissipative particle dynamics.

Dissipative Particle Dynamics (DPD) is a mesoscopic simulation program used to simulate the behavior of complex fluids. This work systematically reviews the use of DPD to simulate the self-assembly process of pH-sensitive drug-loaded nanoparticles. pH-sensitive drug-loaded nanoparticles have the characteristics of good targeting and slow release in the body, which is an ideal method for treating cancer and other diseases. As an excellent simulation method, DPD can help people explore the loading and release laws of drugs with complex molecular structures and has extensive applications in other medical fields. This article reviews the self-assembly process of pH-sensitive polymers under neutral conditions and explores the factors that affect the self-assembly structure. It points out that different hydrophilic-hydrophobic ratios, molecular structures, and component distributions will affect the morphology, stability and drug carrying capacity of micelles. This article also introduces the release mechanism of the drug in detail and introduces the factors that affect the release. This article can help relevant researchers to follow the latest advances in the DPD simulation and pH-sensitive drug nano-carrier and insight people to investigate the further application of DPD simulation in biomedical science.

Dissipative Particle Dynamics Aided Design of Drug Delivery Systems: A Review.

A nanocarrier drug delivery system, effectively assisting to improve the solubility, bioavailability, and targeting of drugs in the human body, is a crucial means for treating cancer and other diseases. However, drug carriers usually possess multiple components and complex microstructures, and studies on the formation mechanism and internal structural details of nanocarriers are still incomplete by experimental methods. In order to overcome this adversity, the dissipative particle dynamics (DPD) simulation has been widely used owing to its unique simulation time-space scale and satisfying computing efficiency. In the past decades, more and more kinds of complex nanocarriers with various structures have been successfully characterized, and influencing factors in mounting numbers have also been parametrized. Not only emphasizing on the self-assembly structure of nanocarriers, but the application area of DPD simulation has also become a complete system covering from the synthesis and preparation to interaction with the biomembrane. This article reviews the application of DPD simulations in drug delivery systems. We have established the connection between existing studies and proposed some outlooks for the further combination between DPD simulation and the design of a drug delivery system.