Investigation on the Interactions between Self-Assembled β-Sheet Peptide Nanofibers and Model Cell Membranes.

Akio Kobori,Ayane Kasai,Tomonori Waku,Naoki Tanaka

doi:10.3390/ijms21249518

Abstract

Self-assembled peptide nanofibers (NFs) obtained from β-sheet peptides conjugated with drugs, including antigenic peptides, have recently attracted significant attention. However, extensive studies on the interactions of β-sheet peptide NFs with model cell membranes have not been reported. In this study, we investigated the interactions between three types of NFs, composed of PEG-peptide conjugates with different ethylene glycol (EG) lengths (6-, 12- and 24-mer), and dipalmitoylphosphatidylcholine (DPPC) Langmuir membranes. When increasing the EG chain length, those interactions significantly decreased considering measurements in the presence of the NFs of: (i) changes in surface pressure of the DPPC Langmuir monolayers and (ii) surface pressure–area (π–A) compression isotherms of DPPC. Because the observed trend was similar to the EG length dependency with regard to cellular association and cytotoxicity of the NFs that was reported previously, the interaction of NFs with phospholipid membranes represented a crucial factor to determine the cellular association and toxicity of the NFs. In contrast to NFs, no changes were observed with varying EG chain length on the interaction of the building block peptide with the DPPC membrane. The results obtained herein can provide a design guideline on the formulation of β-sheet peptide NFs, which may broaden its potential.

Highlights

Nano-sized materials have been widely used for biomedical applications, such as drug delivery systems [1]
Changes in surface pressure with time under a constant trough area were recorded to investigate the interaction between NFs and the DPPC membrane (Figure 2a)
The addition of EG6 NFs caused an increase in π

Summary

Introduction

Nano-sized materials have been widely used for biomedical applications, such as drug delivery systems [1]. The intrinsic surface properties of these materials, such as charge and hydrophobicity, affect their interaction with cellular membranes [2]. In nanomaterials’ design with specific properties according to their applications, the understanding of the interactions between nanomaterials and cell membranes is important [4,5]. Langmuir monolayers containing lipids is one of the commonly used systems to study the interactions between nanomaterials and model cell membranes [17,18,19,20,21,22,23,24,25,26,27,28]. The surface pressure of the Langmuir monolayer is related to the molecular lateral packing of lipids in the monolayer [29], and it is influenced by interactions between the nanomaterials and lipids. Surface pressure measurements in the lipid monolayer under the presence of a nanomaterial can provide information on the interactions between them

Methods

Results

Discussion

Conclusion