Synthesis and Application of Integrin Targeting Lipopeptides in Targeted Gene Delivery

Abstract

One of the main problems facing gene therapy is the ability to target the delivery of DNA to specific cells of choice. Recently, we developed a synthetic nonviral vector platform system known as LMD (liposome:mu:DNA) that was designed for further modular upgrading with tool-kits of chemical components. First-generation LMD systems were prepared from DC-Chol/DOPE cationic liposomes (DC-Chol=3beta-[N-(N',N'-dimethylaminoethane)carbamoyl] cholesterol, DOPE=dioleoyl-L-alpha-phosphatidylethanolamine), mu peptide from the adenovirus core and plasmid DNA (pDNA). Here we report attempts to realise peptide-targeted gene delivery that build upon the LMD platform. Our strategy was to prepare novel lipopeptides with a lipid moiety designed to insert into the outer lipid bilayer of LMD particles whilst simultaneously presenting a peptide moiety for cell-surface receptor binding. One main functional peptide sequence was selected (PLAEIDGIELA; tenascin peptide sequence) known to target alpha(9)beta(1)-integrin proteins predominant on upper-airway epithelial cells. This sequence was investigated along with a corresponding control sequence. The syntheses of two classes (A and B) of lipopeptides are reported; the syntheses of class A lipopeptides requires a modification of Mitsunobu chemistry that could be of general utility to facilitate Mitsunobu reactions in other diverse systems. "Targeted" LMD and LD transfections with class A or B lipopeptides exhibit nonspecific peptide enhancements (up to one order of magnitude) over nonlipopeptide control transfections but few specific effects. Specific targeting effects can be seen if the overall LMD or LD particle cationic charge is lowered, but nonspecific effects are never eliminated. Whilst promising, these data now highlight the need for in vivo data and even a new modular, aqueous chemistry for the controlled adaptation of LMD particles in buffer in order for successful peptide-targeted, synthetic, nonviral gene delivery to be realised.

Pyridylhydrazone-based PEGylation for pH-reversible lipopolyplex shielding

“…Synthesis was performed similar as published in [28,29] with some modifications (Supplement Fig. 1).…”

Effect of the Head-Group Geometry of Amino Acid-Based Cationic Surfactants on Interaction with Plasmid DNA

“…This was demonstrated with, for example, hydrophobically modified spermidine 24,25 and amphiphilic peptides (lipopeptides). 15,26,27 The self-assembly of amphiphilic molecules, like surfactants, can lead to a large variety of structures, including discrete spherical or slightly anisometric aggregates, long cylindrical aggregates, and bilayers. The type of self-assembly structure formed depends on the optimal packing of the amphiphilic molecules, which in turn can be related to the balance between hydrophilic and hydrophobic properties.…”

Recombinant high-density lipoprotein nanoparticles containing gadolinium-labeled cholesterol for morphologic and functional magnetic resonance imaging of the liver

“…Initially, cholesterol was conjugated with ethylenediamine to generate cholesterylamine 3 using Waterhouse's method. 24 In step 2, DTPA-bisanhydride 4 was reacted with the amine group of cholesterylamine 3 to produce a mixture of DTPA-cholesterol 5 and DTPA-(cholesterol) 2 6. These two compounds were separately collected by silica gel column chromatography.…”