Fig. 1

Particle characterization by microscopy. a: TEM analysis of fND aggregates that contained very small mfNDs (few nm). b: The red specific fluorescence of mfNDs excited by a 532 nm laser source. c: mfNDs luminescence spectrum with a specific peak at 700 nm. d: Schematic representation of the possible hydrogen bonds between the hydroxyl groups of the HPG chains and that of alum. e and f: The nanofibrous morphology of alum and vaccine aggregates (ENGERIX B^®) by TEM analysis. g and h: The AluDia complex analyzed by TEM in which alum keeps its nanofibrous morphology and is loaded by non-fibrous, electron dense mfNDs. i-k: Fluorescence microscopy observation of an AluDia agglomerate. Red fluorescence of AluDia particles excited by a 532 nm laser source (i). Alum of AluDia complex stained with Morin and detected by a green fluorescence with a characteristic 520 nm emission when excited at 420nm (j), colocalization of the red fluorescence of mfNDs and the green Morin fluorescence of alum (k), without alteration of the typical mfND emission spectrum (l). AluDia Alhydrogel^® and mfND complex, HPG hyperbranched polyglycerol, mfNDs modified fluorescent nanodiamonds, TEM transmission electron microscope