Modeling of highly efficient drug delivery system induced by self-assembly of nanocarriers: A density functional study

Adsorption of hairy particles with mobile ligands: Molecular dynamics and density functional study

We study models of hairy nanoparticles in contact with a hard wall. Each particle is built of a spherical core with a number of ligands attached to it and each ligand is composed of several spherical, tangentially jointed segments. The number of segments is the same for all ligands. Particular models differ by the numbers of ligands and of segments per ligand, but the total number of segments is constant. Moreover, our model assumes that the ligands are tethered to the core in such a manner that they can "slide" over the core surface. Using molecular dynamics simulations we investigate the differences in the structure of a system close to the wall. In order to characterize the distribution of the ligands around the core, we have calculated the end-to-end distances of the ligands and the lengths and orientation of the mass dipoles. Additionally, we also employed a density functional approach to obtain the density profiles. We have found that if the number of ligands is not too high, the proposed version of the theory is capable to predict the structure of the system with a reasonable accuracy.

Differences in physicochemical properties to consider in the design, evaluation and choice between microparticles and nanoparticles for drug delivery

INTRODUCTION

The increase in the development of novel nanoparticle drug delivery systems makes the choice between micro- and nanoscale drug delivery systems ubiquitous. Changes in physical and chemical properties between micro- to nanosized particles give them different properties that influence their physiological, anatomical and clinical behavior and therefore potential application.

AREAS COVERED

This review focuses on the effect changes in the surface-to-volume ratio have on the thermal properties, solubility, dissolution and crystallization of micro- versus nanosized drug delivery systems. With these changes in the physicochemical properties in mind, the review covers computational and biophysical approaches to the design and evaluation of micro- and nanodelivery systems. The emphasis of the review is on the effect these properties have on clinical performance in terms of drug release, tissue retention, biodistribution, efficacy, toxicity and therefore choice of delivery system.

EXPERT OPINION

Ultimately, the choice between micro- and nanometer-sized delivery systems is not straightforward. However, if the fundamental differences in physical and chemical properties are considered, it can be much easier to make a rational choice of the appropriate drug delivery system size.

A spontaneous penetration mechanism of patterned nanoparticles across a biomembrane

Recent experimental studies have shown the ability of tailoring the nanoparticle (NP)-cell interaction via the engineering of NP surfaces. Although the considerable progress has been made in design of patterned NPs for drug delivery, the effect of surface pattern on the NP-cell interaction is not fully understood yet. In this work, we used a dissipative particle dynamics method to systematically investigate the effects of NP surface pattern on its penetration across a membrane. For stripy NPs or patchy NPs having a large stripe width or patch size, an "insertion-rotation" penetration mechanism is found. Results indicate that stripy NPs and patchy NPs coated with narrow stripes or small patches can directly penetrate the cell membrane with a less constrained rotation. By considering the spontaneous penetration of many NPs into a vesicle, we found that NP aggregation would lead to the shape change of the vesicle, and therefore cause the leakage of encapsulated solvent or membrane rupture, implying the possible cytotoxicity. In short, this work gives a fundamental understanding for the penetration mechanism of the ligand patterned NPs, which provides useful reference for the design of NPs for controllable cell penetrability and targeted delivery of drugs.