2 research outputs found
Design of a Homogeneous Multifunctional Supported Lipid Membrane on Layer-by-Layer Coated Microcarriers
Key challenges in the development
of drug delivery systems are
the prevention of serum compartment interaction and the targeted delivery
of the cargo. Layer-by-Layer microcarriers offer many advantages due
to various options in drug assembly and multifunctional design. Surface
modification with a supported lipid membrane enhances biocompatibility,
drug protection ability, and specific functionality. However, the
integration of functionalized lipids strongly influences the membrane
formation and is often accompanied by submicrometer irregularities:
The accessibility of underlying polymers to serum components may change
the carrier’s properties and enhances the susceptibility to
opsonization. Therefore, the formation of a tightly assembled multifunctional
lipid membrane has been emphasized. A phosphatidylserine/phosphatidylcholine
(POPS/POPC) bilayer equipped with phosphatidylethanolamine–polyethylene
glycol–biotin (PE-PEG-Biotin) was used to facilitate a biotin/streptavidin
binding site for a variable attachment of an additional function,
such as antibodies for specific targeting. Thus, a prefunctionalized
carrier where only the outer functionality needs to be replaced without
disturbing the underlying structure could be created
Specific Uptake of Lipid-Antibody-Functionalized LbL Microcarriers by Cells
The
modular construction of Layer-by-Layer biopolymer microcarriers
facilitates a highly specific design of drug delivery systems. A supported
lipid bilayer (SLB) contributes to biocompatibility and protection
of sensitive active agents. The addition of a lipid anchor equipped
with PEG (shielding from opsonins) and biotin (attachment of exchangeable
outer functional molecules) enhances the microcarrier functionality
even more. However, a homogeneously assembled supported lipid bilayer
is a prerequisite for a specific binding of functional components.
Our investigations show that a tightly packed SLB improves the efficiency
of functional components attached to the microcarrier’s surface,
as illustrated with specific antibodies in cellular application. Only
a low quantity of antibodies is needed to obtain improved cellular
uptake rates independent from cell type as compared to an antibody-functionalized
loosely packed lipid bilayer or directly assembled antibody onto the
multilayer. A fast disassembly of the lipid bilayer within endolysosomes
exposing the underlying drug delivering multilayer structure demonstrates
the suitability of LbL-microcarriers as a multifunctional drug delivery
system