Cytosolic drug delivery using DNA-based nanocarriers coated with cell-targeted antibodies.
The ability to deliver drugs intracellularly is critical for the treatment of diseases caused by aberrant processes within the cell. However, current drug delivery methods are ineffective at reaching the cell interior beyond the membranes of the endocytic vesicles. Problems with state-of-the-art intracellular drug delivery systems include puncturing the plasma membrane and causing cell death, being degraded by the cell, or an inability to deliver large cargo. Therefore, a drug delivery method that bypasses degradation processes and reaches the cell interior compartments via the cytosol without harming the cell would have immense therapeutic potential.
Two main components of the new delivery system that effectively transports diverse cargoes into the cytosol are nanocarriers with unique material and structural characteristics, coupled with affinity ligands that provide binding to specific cell populations followed endocytosis and subsequent fortuitous transfer to the cytosol. Unlike other drug vehicles, the technology enables therapeutics and other cargo to avoid cell degradation pathways, allowing for efficient delivery of the drug to the cell interior. The nanocarriers also avoid disrupting the plasma membrane and are naturally disposed by the cells, making it safe for the internalizing cell.
The inventors coat commercially available DNA dendrimers with cellular adhesion molecule (CAM) antibodies to create the targeted nanocarriers. The dendrimers can then be loaded with a therapeutic agent. The nanocarriers bind to and cluster CAM on the cell surface, activating an endocytic pathway. This pathway is distinct from clathrin-mediated or caveolar endocytosis, which may be compromised in certain diseases. Once endocytosed, the nanocarriers allows the drug to escape the lysosomal degradation pathway and enter the cytosol. The DNA dendrimers are then degraded, releasing the drug and avoiding protein aggregation and cytotoxicity.
Top panels show a nanocarrier built with DNA (ND) which is capable of delivering inside cells: (left panel) a toxin (phalloidin) which then accesses the cell cytoskeleton, (middle panel), a protein (albumin) linked to a nuclear localization signal (NLS) and can access the cell nucleus, and (right panel) a plasmid which results in the cytoplasmic expression of then protein RhoA linked to green fluorescent protein (EGFP). Bottom panels show lack of cytoskeleton, nuclear, and cytoplasmic location of these agents when delivered with classical polymer nanoparticles (NPs) Muro-Galindo; Adv Funct Mater, 2014, 24(19):2899.
- Avoids disease-compromised pathways for cell internalization
- Avoids cell degradation pathways prior to cytosolic drug delivery
- Does not disrupt plasma membrane
- Does not cause cellular toxicity
- Does not aggregate intracellularly
- Provides cytosolic delivery of diverse cargoes including proteins and nucleic acids
Stage of Development:
Therapeutics - Preclinical Discovery
- Issued Patent: US9707299B2
- Patent application pending in other countries
Docket # T4312