Transdermal Penetrating Peptide Conjugated Liposomes as Drug Delivery Carrier Comprising Macromolecules

doi:10.17762/turcomat.v12i5.977

Abstract

: The aim of the study was to investigate a system using liposomes and cell penetrating peptides (CPP) for optimal transdermal delivery of macromolecules. Typical DOPE liposomes were prepared with lipid mixture (DOPE:PC:Chol = 1.5:1.5:2.0, molar ratio) and active materials (Rhodamine B; MW ~480 and Dextran-RITC; MW ~10,000). CPP-conjugated DOPE liposomescontaining active materials were prepared by conjugating the peptide to DOPE liposomes (DOPE:PC:Chol:DSPE-PEG-Mal = 1.5:1.1:2.0:0.2 or 0.4, molar ratio). Physical properties of both liposomes were evaluated, including particle size and zeta potential. The particle sizes of typical liposome and CPP-DOPE liposome were approximately 100 nm, and the zeta potential values of both liposomes were approximately -25mV and over +11mV respectively. Moreover, cellular uptake efficiency was assessed by flow cytometry (FACS). CPP-conjugated liposomes resulted higher cellular uptake efficiency compared to typical DOPE liposomes, showing higher fluorescent intensity in CPP-DOPE liposomes. In confocal laser scanning microscope (CLSM) studies, both cellular uptake and skin permeation were visually estimated. In the case of Rhodamine B, having a relatively small molecular weight,absorption into the cell was successful, and showed the highest rate of cellular uptake with CPP-DOPE liposomes. Dextran-RITC, a macromolecule with a relatively bigger molecular weight, showed similar results to Rhodamine B. In terms of skin permeation, CPP-DOPE liposomes containing Rhodamine B showed noticeable skin absorption after 4 and 18 hours, and the permeation range was wider and thicker than that with typical liposomes. For Dextran-RITC, with typical DOPE liposome, it was hardly permeable through the skin, but with CPP-DOPE liposomes, on the other hand, the skin permeations after 4 and 18 hours were remarkable. The improved cellular uptake and skin permeation of the CPP-conjugated liposomes are due to the cationic arginine-rich peptide. In vivo studies also proved that the CPP-conjugated liposomes are superior in depigmentation and anti-wrinkle studies than typical liposomes. These results demonstrate that the CPP-conjugated liposomes could also be effective for transdermal drug delivery of antioxidant and anti-aging therapeutics.

Highlights

Hydrophilic and huge substances cannot go into cells due to the barrier of cell membranes
The zeta potential of the DOPE liposome and cell penetrating peptides (CPP)–DOPE liposome was -27.5mV and +34.8mV, respectively. This change was primarily due to the arginine moieties in the cationic peptide, indicating that DOPE liposomes were successfully conjugated with the CPP peptide on the liposomal surface
These data represented that CPP-conjugated liposomes have higher cellular uptake efficiency than typical DOPE liposomes

Summary

Introduction

Hydrophilic and huge substances cannot go into cells due to the barrier of cell membranes. New alternatives have recently been proposed, of which CPP is under the spotlight as they can increase the availability of large molecules such as siRNA [1,2], protein [3] and peptides [4] that were difficult to utilize as drugs due to low cell membrane permeability and rapid in vivo half-life. Short arginine oligomers facilitatetransporting across the cutaneous barrier when applied topically to either mouse or human skin [6]. From the result of these studies, short arginine oligomers are expected to be used as a transdermal delivery system. We designed a system using liposomes and CPP for optimal transdermal delivery. The cellular uptake and skin permeation of both liposomes were examined using flow cytometry and Confocal Laser Scanning Microscope(CLSM), respectively

Objectives

Methods

Results

Conclusion