Polymer-Lipid Hybrid Vesicles and Their Interaction with HepG2 Cells

Area of Science:

• Nanotechnology
• Biomaterials Science
• Cell Biology

Background:

• Polymer-lipid hybrid vesicles are promising nano-assemblies for applications like artificial organelles.
• Understanding the behavior and stability of these hybrid vesicles within cellular environments is crucial for their development.

Purpose of the Study:

• To synthesize and characterize polymer-lipid hybrid vesicles with homogenous membrane distribution.
• To evaluate the cytotoxicity and cellular uptake of these hybrid vesicles.
• To investigate the intracellular fate of the lipid and polymer components within cells.

Main Methods:

• Assembly of hybrid vesicles using phospholipids and a specific block copolymer (poly(cholesteryl methacrylate)-block-poly(methionine methacryloyloxyethyl ester (METMA)-random-2-carboxyethyl acrylate (CEA))) labeled with Förster resonance energy transfer (FRET) reporters.
• Characterization of vesicle homogeneity using FRET.
• Cytotoxicity assays using HepG2 cells.
• Cellular uptake and intracellular fate studies using fluorescence microscopy.

Main Results:

• Successfully assembled small and giant hybrid vesicles with homogenous distribution of phospholipids and block copolymer, confirmed by FRET.
• Hybrid vesicles exhibited no inherent cytotoxicity towards HepG2 cells at high concentrations (up to 1.1 × 10^11/mL).
• Vesicles were internalized by HepG2 cells, with lipids showing significantly lower detectability after 30 hours compared to the block copolymer, indicating differential intracellular degradation or localization.

Conclusions:

• The study demonstrates successful fabrication of stable polymer-lipid hybrid vesicles with uniform membrane composition.
• These hybrid vesicles are non-cytotoxic and readily internalized by cells, supporting their potential as artificial organelles.
• The distinct intracellular behavior of lipid and polymer components provides key insights for designing artificial organelles with specific structural integrity and functional properties.