Author(s):
Oliveira, Joaquim M. 
; Kotobuki, Noriko ; Marques, A. P. ; Pirraco, Rogério ; Benesch, Johan ; Hirose, Motohiro ; Costa, Silgia ; Mano, J. F. ; Hajime, Ohgushi ; Reis, R. L.
Date: 2008
Persistent ID: http://hdl.handle.net/1822/20299
Origin: RepositóriUM - Universidade do Minho
Description
Novel highly branched biodegradable macromolecular systems have been developed by grafting carboxymethylchitosan
(CMCht) onto low generation poly(amidoamine) (PAMAM) dendrimers. Such structures organize into sphere-like nanoparticles
that are proposed to be used as carriers to deliver bioactive molecules aimed at controlling the behavior of stem cells,
namely their proliferation and differentiation. The nanoparticles did not exhibit significant cytotoxicity in the range of
concentrations below 1 mg mL"1, and fluorescent probe labeled nanoparticles were found to be internalized with highly
efficiency by both human osteoblast-like cells and rat bone marrow stromal cells, under fluorescence-activated cell sorting and
fluorescence microscopy analyses. Dexamethasone (Dex) has been incorporated into CMCht/PAMAM dendrimer nanoparticles
and release rates were determined by high performance liquid chromatography. Moreover, the biochemical data demonstrates
that the Dex-loaded CMCht/PAMAM dendrimer nanoparticles promote the osteogenic differentiation of rat bone marrow
stromal cells, in vitro. The nanoparticles exhibit interesting physicochemical and biological properties and have great potential to
be used in fundamental cell biology studies as well as in a variety of biomedical applications, including tissue engineering and
regenerative medicine.
