lipidcoated

Lipidcoated describes materials whose surface or exterior is covered by a layer of lipid, typically formed from amphiphilic phospholipids and cholesterol. This coating can create a lipid bilayer as in liposomes or a lipid monolayer on an inorganic or polymer core, resulting in lipid-coated nanoparticles. The lipid shell provides biocompatibility, can reduce nonspecific interactions, and can be engineered to carry therapeutic or diagnostic cargo.

Lipid-coated systems may use cores such as gold, silica, or polymer particles. The lipid layer can encapsulate hydrophilic drugs within aqueous compartments, or house hydrophobic drugs within the lipid phase. Design parameters include lipid composition, cholesterol content to modulate membrane rigidity, and surface modification with polyethylene glycol (PEG) to increase circulation time and enable attachment of targeting ligands or imaging agents. Methods to create lipid-coated particles include adsorption of lipids onto preformed cores, fusion of liposomes with particles, and solvent-exchange techniques to form lipid shells around cores.

Applications span drug delivery, gene therapy, and diagnostic imaging, with lipid-coated vesicles and nanoparticles serving as carriers or contrast agents. Liposomes are a common example of lipid-coated vesicles. Lipid-coated gold nanoparticles and lipid-coated silica particles are used in imaging, photothermal therapy, and theranostics, illustrating the versatility of this coating approach.

Challenges include stability in biological fluids, potential lipid exchange between particles, immunogenicity concerns, and manufacturing reproducibility at scale. Despite these issues, lipid-coated systems remain a prominent strategy for improving biocompatibility and cargo delivery in biomedical research.