Interaction of S-layer proteins of Lactobacillus kefir with model membranes and cells

Abstract

In previous works, it was shown that S-layer proteins from Lactobacillus kefir were able to recrystallize and stabilize liposomes, this feature reveling a great potential for developing liposomal-based carriers. Despite previous studies on this subject are important milestones, a number of questions remain unanswered. In this context, the feasibility of S-layer proteins as a biomaterial for drug delivery was evaluated in this work. First, S-layer proteins were fully characterized by electron microscopy, 2D-electrophoresis, and anionic exchange chromatography coupled with pulsed amperometric detection (HPAEC-PAD). Afterward, interactions of S-layer proteins with model lipid membranes were evaluated, showing that proteins adsorb to the lipid surface following a non-fickean or anomalous diffusion, when positively charged lipid were employed, suggesting that electrostatic interaction is a key factor in the recrystallization process on these proteins. Finally, the interaction of S-layer coated liposomes with Caco-2 cell line was assessed: First, cytotoxicity of formulations was tested showing no cytotoxic effects in S-layer coated vesicles. Second, by flow cytometry, it was observed an increased ability to transfer cargo molecules into Caco-2 cells from S-layer coated liposomes in comparison to control ones. All data put together, supports the idea that a combination of adhesive properties of S-layer proteins concomitant with higher stability of S-layer coated liposomes represents an exciting starting point in the development of new drug carriers.

• S-layer proteins
• Lactobacillus kefir
• liposomes
• drug carriers

Acknowledgements

We thank Dr. Vasco Azevedo and all staff of Laboratório de Genética Celular e Molecular, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, for pI determination. This work was supported by grants from Universidad Nacional de Quilmes, Comisión de Investigaciones Científicas de la Provincia de Buenos Aires (CIC-BA) and Agencia Nacional de Promoción Científica y Tecnológica (ANPCyT– MINCyT, Argentina; PICT-1481). Dr. L. Semorile is a member of the Research Career of CIC-BA. Dr. E. A. Disalvo and Dr. Axel Hollmann are members of the Research Career of CONICET.

Declaration of interest

The authors report no declarations of interest.

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