# Direct Retrieval of Biomechanical and Hydrodynamic Parameters for Drug Carrier Liposomes Using Conventional Extrusion Processes

## TL;DR

This paper introduces methods to measure liposome properties using standard lab techniques, improving drug delivery predictions.

## Contribution

The paper presents two novel protocols using extrusion and dynamic light scattering to evaluate liposome biomechanics and hydrodynamics.

## Key findings

- Extrusion pressure variations can determine solution viscosity in liposome suspensions.
- Dynamic light scattering provides elasticity constants by analyzing particle size distribution.
- The methods offer realistic and integrative characterization compared to microscopic techniques.

## Abstract

Physical parameters such as membrane elasticity and solution
viscosity
in a liquid medium play crucial roles in the effectiveness of drug
delivery. Liposome formulations, used in both research and clinical
contexts, are usually designed to achieve desired chemical stability,
particle size, and drug encapsulation efficiency. However, meeting
such requirements may not suffice in order to succeed in in vivo tests,
which can be frustrated due to poor evaluation of biomechanical conditions.
In this work, we introduce simple biomechanical evaluation protocols
that make use of conventional pressure-based liposome extrusion as
well as dynamic light scattering results to extract elastic (mechanical)
and hydrodynamic (viscosity) properties of colloidal solutions of
liposomes. We describe a sequence of analytical steps that need to
be carried out in order to obtain macroscopic results that are directly
comparable to those of other methods. Two distinct and complementary
procedures are presented: the first uses a systematic variation of
extrusion pressure, giving access to the viscosity of the solution,
and the second being a statistical evaluation of the particle size
distribution obtained by dynamic light scattering, providing elasticity
constants for liposomal systems. Both methods carry the advantage
of generating results for the liposome suspension that will be applied
to real systems, thereby offering a more realistic and integrative
characterization compared with microscopic techniques that usually
present incomplete statistical coverage.