Nano-Decoration of the Hemagglutinating Virus of Japan Envelope (HVJ-E) Using a Layer-by-Layer Assembly Technique Takaharu Okada, †,‡ Koichiro Uto, ‡ Masao Sasai, § Chun Man Lee, § Mitsuhiro Ebara, ‡ and Takao Aoyagi* ,†,‡ † Graduate School of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577, Japan ‡ Biomaterials Unit, International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan § Medical Center for Translational Research, Osaka University Hospital, 2-15 Yamadaoka, Suita, Osaka 565-0871, Japan * S Supporting Information ABSTRACT: In this study, we created a nanoscale layer of hyaluronic acid (HA) on the inactivated Hemagglutinating Virus of Japan envelope (HVJ-E) via a layer-by-layer (LbL) assembly technique for CD-44 targeted delivery. HVJ-E was selected as the template virus because it has shown a tumor-suppressing ability by eliciting inflammatory cytokine production in dendritic cells. Although it has been required to increase the tumor-targeting ability and reduce nonspecific binding because HVJ-E fuses with virtually all cells and induces hemagglutination in the blood- stream, complete modifications of single-envelope-type viruses with HA have been difficult. Therefore, we studied the surface ζ potential of HVJ-E at different pH values and carefully examined the deposition conditions for the first layer using three cationic polymers: poly-L-lysine (PLL), chitosan (CH), and glycol chitosan (GC). GC-coated HVJ-E particles showed the highest disperse ability under physiological pH and salt conditions without aggregation. An HA layer was then prepared via alternating deposition of HA and GC. The successive decoration of multilayers on HVJ-E has been confirmed by dynamic light scattering (DLS), ζ potentials, and transmission electron microscopy (TEM). An enzymatic degradation assay revealed that only the outermost HA layer was selectively degraded by hyaluronidase. However, entire layers were destabilized at lower pH. Therefore, the HA/GC-coated HVJ-E describe here can be thought of as a potential bomb for cancer immunotherapy because of the ability of targeting CD44 as well as the explosion of nanodecorated HA/GC layers at endosomal pH while preventing nonspecific binding at physiological pH and salt conditions such as in the bloodstream or normal tissues. ■ INTRODUCTION The surface modification of cells, viruses, or bacteria by conjugating with bioactive molecules or synthetic polymers has been a versatile way to add new value, advanced features, and unique properties to inserted ones. Creating a nanoscale layer on them significantly improves or even completely changes their biological properties and introduces new, unique proper- ties such as chemical functionality, 1-3 imaging, 4,5 immune camouflaging, 6,7 maintenance of viability, 8 and control of stability in the body. 9,10 The ability to visualize mammalian cell surfaces in both in vitro and in vivo environments, for example, is essential to gaining further insight into the function of specific molecules or the entire entity. In addition to mammalian cells, myriad viruses and viruslike particles have been genetically and chemically reprogrammed to function as drug- and gene-delivery vehicles 11 and nanomaterials. 12 Gene- delivery vectors based on adenoviral (Ad) vectors, for example, have enormous potential for the treatment of both hereditary and acquired diseases. 13 However, many of the therapeutically relevant target cells for gene therapy are refractory to Ad transduction because of the low expression of primary receptors. The chemical modification of the Ad capsid is one of the most direct approaches to modifying vector tropism. Surface-modified Ads with a multivalent reactive poly[N-(2- hydroxypropyl)methacrylamide] (PHPMA)-based copolymer successfully shielded them from recognition by antibodies. 14 The direct attachment of ligands such as fibroblast growth factor-2 (FGF-2) through bifunctional poly(ethylene glycol) (PEG) has been shown to augment coxsackie and adenovirus receptor (CAR)-independent gene transfer. 15 The reaction to PEG has also been shown to improve the in vivo pharmacokinetics of the vector by increasing the vector persistence in the blood, preventing antibody neutralization. 16 PEG coating also prolonged transgene expression and allowed partial readministration with a native virus. 17 Special Issue: Interfacial Nanoarchitectonics Received: November 15, 2012 Revised: February 25, 2013 Published: February 26, 2013 Article pubs.acs.org/Langmuir © 2013 American Chemical Society 7384 dx.doi.org/10.1021/la304572s | Langmuir 2013, 29, 7384-7392