GISELA LUZ*, LUCIANO BOESEL

1

University of Minho School of Engineering 3B's Research Group
MICROPATTERNING OF BIOACTIVE GLASS NANOPARTICLES
ON CHITOSAN MEMBRANES FOR SPATIAL CONTROLLED
BIOMINERALIZATION
GISELA LUZ, LUCIANO BOESEL Supervisors
Aránzazu del Campo and João F. Mano
gisela.luz_at_dep.uminho.pt
Bioactivity study Bioactivity of the BG-NPs
patterns was assessed in vitro by analyzing with
Energy dispersive X-ray analysis (EDX), Scanning
electron microscopy (SEM) and Fourier Transform
Infrared Spectroscopy (FTIR) the ability of
calcium phosphates formation by immersing the
samples in SBF.
Introduction Bioactive glass nanoparticles
(BG-NPs) capable of bone regeneration were
patterned on biocompatible chitosan membranes by
a microcontact printing technique, using a PDMS
stamp. The aim of this work was to produce
perfectly defined bioactive micropatterns, and
therefore to spatially control biomineralization
and cell attachment on chitosan membranes.
Spatial control of biomineralization and cell
attachment
SBF soaking
Chitosan membrane
BG-NPs patterning
Biomineralized pattern
Procedure
Cell Culture
Cell pattern
(1)
Fig. 2 Apatite crystals grew in the area printed
with the BG-NPs after SBF immersion. Cell culture
also proved that cells attach according to the
defined BG-NPs pattern.
(2)
(6)
Viability study L929 mouse fibroblasts line was
used to test the in vitro biocompatibility of the
membranes through MTS assay. BG-NPs patterned
membranes demonstrated increased cell viability
over the time point of culture period (1, 3 and 7
days). Oppositely, the viability of cells seeded
in plain chitosan membranes, decreased.
(5)
(3)
(4)
Fig. 1 (1) The PDMS stamp is prepared by
pouring a prepolymer of the elastomer over a
master prepared by photolithography, then cured,
peeled off and cut . (2) 549µl of BG-NP in
ethanol will be poured on a limited surface of a
glass slide and left to evaporate inside a
saturated chamber. (3) Inking of the stamp in
BG-NPs. (4) Printing on the chitosan
membrane. (5) Lift-off. (6) Ethanol washing and
drying.
Chitosan day 1
(a)
Fig. 4 (a) EDX analysis of the bioactivity study
of the BG-NPS patterned chitosan membranes soaked
in SBF for different time points (0, 1, 3, 5 and
7 days). (b) Original BG-NPs pattern. (c) FTIR
spectra of the powder scratched from the surface
of the patterned membranes after 0 (control) and
7 days of immersion in SBF. (d) SEM images of the
typical apatite clusters after 5 days of soaking
of the patterned samples in SBF.
BG-NPs pattern day 1
(b)
(c)
Fig. 3 Fluorescent images of cell stained with
Calcein AM after 1 day of culture in plain
chitosan (a) and BG-NPs patterned membranes (b)
(c) Cell viability results from MTS test.
Acknowledgments This work was supported by FCT,
through project PTDC/QUI/69263/2006 and the PhD
grant SFRH/BD/45777/2008.
Uma Escola a Reinventar o Futuro Semana da Escola de Engenharia - 24 a 27 de Outubro de 2011