Polymer coated liposomes for use in the oral cavity – a study of the in vitro toxicity, effect on cell permeability and interaction with mucin

Abstract

In this study we investigated the in vitro toxicity, impact on cell permeability and mucoadhesive potential of polymer-coated liposomes intended for use in the oral cavity. A TR146 cell line was used as a model. The overall aim was to end up with a selection of safe polymer coated liposomes with promising mucoadhesive properties for drug delivery to the oral cavity. The following polymers were tested: chitosan, low-methoxylated pectin (LM-pectin), high-methoxylated pectin (HM-pectin), amidated pectin (AM-pectin), Eudragit, poly(N-isopropylacrylamide-co-methacrylic acid) (p(NIPAAM-co-MAA)), hydrophobically modified hydroxyethyl cellulose (HM-HEC), and hydrophobically modified ethyl hydroxyethyl cellulose (HM-EHEC). With chitosan as an exception, all the systems exhibited no significant effect on cell viability and permeability at the considered concentrations. Additionally, all the formulations showed to a varying degree an interaction with mucin (BSM type I-S); the positively charged formulations exhibited the strongest interaction, while the negatively and neutrally charged formulations displayed a moderate or low interaction. The ability to interact with mucin makes all the liposomal formulations promising for oromucosal administration. Although the chitosan-coated liposomes affected the cell viability, this formulation also influenced the cell permeability, which makes it an interesting candidate for systemic drug delivery from the oral cavity.

Keywords:

• Liposome
• mucoadhesion
• nanotechnology
• polymer coating
• toxicity

Acknowledgments

The authors would like to thank Tove Larsen (University of Oslo for technical assistance, and laboratory technician Maria D. Læssøe Pedersen (University of Copenhagen) for cultivation of TR146 cells. We would also like to thank MLS^UiO and The Norwegian Pharmaceutical Society for travel grants. Phosphatidylcholine, HM-HEC and HM-EHEC were gifts from Lipoid, Azelis Denmark A/S and Akzo Nobel Chemicals AG, respectively.

Declaration of interest

The authors report no conflict of interest.