Increase in Dye: Dendrimer Ratio Decreases Cellular Uptake of Neutral Dendrimers in RAW Cells

Sriram Vaidyanathan, Milan Kaushik, Casey Dougherty, Rahul Rattan, Sascha N. Goonewardena, Mark M. Banaszak Holl, Janet Monano, Stassi DiMaggio

Research output: Contribution to journalArticleResearchpeer-review

4 Citations (Scopus)

Abstract

Neutral generation 3 poly(amidoamine) dendrimers were labeled with Oregon Green 488 (G3-OGn) to obtain materials with controlled fluorophore:dendrimer ratios (n = 1-2), a mixture containing mostly 3 dyes per dendrimer, a mixture containing primarily 4 or more dyes per dendrimer (n = 4+), and a stochastic mixture (n = 4avg). The UV absorbance of the dye conjugates increased linearly as n increased and the fluorescence emission decreased linearly as n increased. Cellular uptake was studied in RAW cells and HEK 293A cells as a function of the fluorophore:dendrimer ratio (n). The cellular uptake of G3-OGn (n = 3, 4+, 4avg) into RAW cells was significantly lower than G3-OGn (n = 1, 2). The uptake of G3-OGn (n = 3, 4+, 4avg) into HEK 293A cells was not significantly different from G3-OG1. Thus, the fluorophore:dendrimer ratio was observed to change the extent of uptake in the macrophage uptake mechanism but not in the HEK 293A cell. This difference in endocytosis indicates the presence of a pathway in the macrophage that is sensitive to hydrophobicity of the particle.

Original languageEnglish
Pages (from-to)1540-1545
Number of pages6
JournalACS Biomaterials Science & Engineering
Volume2
Issue number9
DOIs
Publication statusPublished - 12 Sept 2016
Externally publishedYes

Keywords

  • dye
  • fluorescence emission
  • HPLC
  • mammalian cell
  • PAMAM dendrimer

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