Lipid membrane editing with peptide cargo linkers in cells and synthetic nanostructures

Abstract

Current strategies for deploying synthetic nanocarriers involve the creation of agents that incorporate targeting ligands, imaging agents, and/or therapeutic drugs into particles as an integral part of the formulation process. Here we report the development of an amphipathic peptide linker that enables postformulation editing of payloads without the need for reformulation to achieve multiplexing capability for lipidic nanocarriers. To exemplify the flexibility of this peptide linker strategy, 3 applications were demonstrated: converting nontargeted nanoparticles into targeting vehicles; adding cargo to preformulated targeted nanoparticles for in vivo site-specific delivery; and labeling living cells for in vivo tracking. This strategy is expected to enhance the clinical application of molecular imaging and/or targeted therapeutic agents by offering extended flexibility for multiplexing targeting ligands and/or drug payloads that can be selected after base nanocarrier formulation.

Suppression of NF-κB activity via nanoparticle-based siRNA delivery alters early cartilage responses to injury

“…We have previously reported that the cationic amphipathic peptide designated as "p5RHH" (VLTTGLPALISWIRRRHRRHC) is capable of siRNA transfection without significant cytotoxicity at all tested doses (8). This novel sequence lacks the toxicity profile of its full parent compound, melittin, because it features a truncation of six terminal amino acids that prevents peptide-induced cytolytic membrane pore formation at low doses in the blood stream (11)(12)(13)), yet when concentrated in endosomes still promotes endosomolysis and siRNA escape (9). The noncovalent coupling, self-assembling formulation strategy is depicted in Fig.…”

“…To circumvent the shortcomings of lipid carriers, we used a peptidic NP structure that represents the culmination of a number of specific sequence modifications to the amphipathic cationic peptide, melittin (12,36,37). In this present version of the peptide, the pore-forming capacity has been intentionally attenuated while still permitting membrane penetration, thus facilitating endosomal escape and coordinated release of siRNA into cytoplasm to avoid deactivation of therapeutic moieties (8,9,11,38). We have previously shown that these particles did not elicit any systemic or adaptive immune responses in an experimental model of rheumatoid arthritis (10).…”

Peptide-siRNA nanocomplexes targeting NF-κB subunit p65 suppress nascent experimental arthritis

“…tions mitigate the undesirable pore-forming capacity of peptide, yet retain its ability to condense siRNA and facilitate endosomal escape, as previously reported (13,16). A simple mixing procedure of only 10 minutes yields a complex that is small enough (~55 nm) to passively diffuse rapidly into inflamed tissues, where it is retained, yet avoids hepatic sequestration (14).…”

“…We recently reported the development of an amphipathic peptide-based siRNA nanoplatform (13,14) that uses a modified version of the bee venom component melittin to transport siRNA (15). Melittin is a well-studied peptide with pore-forming features that derive from its ability to insert into lipid membranes stably through hydrophobic interactions among resident membrane phospholipids interacting with its α-helical peptide secondary structure (16,37,38). Subsequent multimeric oligomerization establishes a membrane pore, resulting in disruption and cell death.…”

State-of-the-Art Methods for Evaluation of Angiogenesis and Tissue Vascularization

“…Pan et al 211 have developed, characterized, and demonstrated a vascular-constrained, αvβ3-targeted gold nanobeacon for the sensitive and specific discrimination of immature angiogenic endothelial vessels from mature microvasculature.…”