A smart viral vector for targeted delivery of hydrophobic drugs

Abstract

Targeted delivery of hydrophobic chemotherapeutic drugs to tumor cells remains a fundamental problem in cancer therapy. Effective encapsulation of hydrophobic drugs in nano-vehicles can improve their pharmacokinetics, bioavailability and prevent off-target localization. We have devised a method for easy chemical conjugation and multivalent display of a tumor-homing peptide to virus-like particles of a non-mammalian virus, Flock House Virus (FHV), to engineer it into a smart vehicle for targeted delivery of hydrophobic drugs. This conjugation method provides dual functionalization to the VLPs, first, a 2 kDa PEG spacer arm shields VLPs from immune reactivity, and second, attachment of the tumor homing peptide tLyP-1 chauffeurs the encapsulated hydrophobic drugs to target cells. The fortuitous affinity of the FHV capsid towards hydrophobic molecules, and dependence on Ca2+ for maintaining a stable capsid shell, were utilized for incorporation of hydrophobic drugs—doxorubicin and ellipticine—in tLyP-1 conjugated VLPs. The drug release profile from the VLP was observed to be gradual, and strictly endosomal pH dependent. We propose that this accessible platform empowers surface functionalization of VLP with numerous ligands containing terminal cysteines, for generating competent delivery vehicles, antigenic display and other biomedical applications.

Hydrophobic Cargo Encapsulation into Virus Protein Cages by Self-Assembly in an Aprotic Organic Solvent

“…The same peak wavelength for free Bdpy in DMSO and VLP-Bdpy (Figure 3c) is likely due to the fact that DMSO has a similar refractive index to the CP 15,61 and suggests that in VLP-Bdpy, the dye is mostly surrounded by a medium different from water, i.e., it must be in tight contact with the protein. We note that trapping of hydrophobic molecules in viral capsids has been demonstrated previously, 62,63 but it has not been accomplished until now by coassembly of CP and dyes in a DMSO solution.…”

“…, it must be in tight contact with the protein. We note that trapping of hydrophobic molecules in viral capsids has been demonstrated previously, , but it has not been accomplished until now by co-assembly of CP and dyes in a DMSO solution.…”

Chimeric virus-like particles (VLPs) designed from shrimp nodavirus (MrNV) capsid protein specifically target EGFR-positive human colorectal cancer cells

“…One excellent example to show GE11 specificity is the genetic fusion of GE11 into adenovirus 5 (Ad5) virus particle at the AB loop of the viral fiber knob (so called KO1 mutation) which significantly decreases binding of Ad5 towards the recipient cells while reversely enhances the internalization of the chimeric Ad5 into EGFR positive cell lines 36 . The other example of chemically modified nodavirus (Flockhouse virus or FHV, structurally homolog to MrNV) with tumour homing peptide has shown recently to successfully deliver hydrophobic drugs into EGFR-positive breast cancer cells, a closely-resembled example to MrNV reported herein 37 .…”

Engineering Self-Assembling Protein Nanoparticles for Therapeutic Delivery

“…Protein nanoparticle carriers possess an interior cavity for encapsulation of hydrophobic small molecules (Figure E). For example, ferritin nanoparticles have been engineered to encapsulate doxorubicin, cisplatin, and other small molecule therapeutics. ,,,− Drug-loaded ferritin nanoparticles have not yet been clinically approved due to complexity in manufacturing and specific tissue targeting, but promising advancements are underway.…”