Canine parvovirus-like particles, a novel nanomaterial for tumor targeting

Conventional chemotherapy for treating cancer is non-selective and therefore associated with toxic side effects, limiting a drug's therapeutic index [1-4]. Targeted delivery of drugs is ideal in order to enhance therapeutic benefit as well as reduce systemic toxicity. Recently the development of novel methods to achieve specific tumor targeting has received significant focus [5,6]. Strategies investigated towards this goal include "smart" tissue-specific particles such as liposomes [7], antibodies [8,9], viral particles [10-12] and dendrimers [13] that are comprised of targeting moieties and cytotoxic drugs.Currently virus-based nanoparticles (VBNPs) are being extensively investigated for nanobiotechnology applications [12,14]. Many viral particles are in the nanometer size range and are naturally uniform in size because of the structural constraints on capsid assembly. An increasing number of three-dimensional virus structures known to atomic resolution paved the way for derivatization of VBNPs with dyes, metals, peptides, proteins, and small molecules and is being explored for generating novel nanomaterials. In the last decade several VBNPs have been examined for diverse applications such as templates for material synthesis, platforms for polyvalent display, electronic components, and drug targeting [14-19]. Typical characteristics for a VBNP platform qualification include knowledge about its crystal structure, ability to produce in substantial quantities, stability in a wide range of pH, and suitability for genetic manipulation as well as chemical bioconjugation. Viruses and virus-like particles (VLPs) that have been developed for nanotechnology purposes include bacteriophages (M13 and MS2 [16,20]), plant viruses (cowpea mosaic virus (CPMV), cowpea chlorotic mottle virus (CCMV) and tobacco mosaic virus(TMV) [15,18,21,22]), an insect virus (flock house virus [23]), and animal viruses (adenovirus, polyoma virus [24,25]). While infectious plant viral particles can b