Influence of side chain length on fluorescence intensity of ROMP-based polymeric nanoparticles and their tumor specificity in in-vivo tumor imaging.

Small 2011 Dec 31;7(24):3536-47. Epub 2011 Oct 31.

Department of Energy and Hydrocarbon Chemistry, Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8510, Japan.

In this study, amphiphilic brush-like copolymers conjugated with short alkyl or long polymeric chains of various lengths are synthesized using ring-opening metathesis polymerization (ROMP) of substituted norbornadiene monomers followed by chemical transformations. These amphiphilic copolymers form spherical self-assemblies in aqueous media with diameters of 132-244 nm. The low critical aggregation concentration of these assemblies (2.5 × 10(-3) -1.4 × 10(-5) g/L) indicates that they are quite stable in dilute conditions. An appropriate length of polymer side chain that conjugates the polymer backbone with a hydrophobic ICG (indocyanine green) moiety enhanced the fluorescence intensities of these self-assemblies in aqueous solution as well as in tumor-bearing mice. A longer side chain conjugated with tumor targeting agents could significantly affect the tumor specificity of self-assemblies to a greater extent. The self-assemblies bearing hydrophilic tumor targeting agents, such as a glucosamine molecule and a cyclic RGD (arginine-glycine-asparatic acid) peptide, accumulated in tumor tissues with high selectivity, while those having a hydrophobic targeting agent, such as folate moieties, accumulated in tumor sites with low selectivity. The results demonstrated here unambiguously indicate that the fluorescence intensity and tumor specificity of self-assemblies are strongly affected by the length of side chains that conjugate with dyes and targeting agents.

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http://dx.doi.org/10.1002/smll.201101637DOI Listing
December 2011
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References

(Supplied by CrossRef)

Weissleder et al.
Radiology 2001

Herschman et al.
Science 2003

Kim et al.
Chem. Rev. 2010

Kobayashi et al.
Chem. Rev. 2010

Discher et al.
Science 2002

Osada et al.
Adv. Polym. Sci. 2006

Torchilin et al.
Pharm. Res. 2007

Park et al.
Adv. Funct. Mater. 2009

Minelli et al.
Small 2010

Koo et al.
Nano Today 2011

Matsumura et al.
Cancer Res. 1986

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