Author(s):
Oliveira, S. M. 
; Silva, Tiago H. ; Reis, R. L. ; Mano, J. F.
Date: 2013
Persistent ID: http://hdl.handle.net/1822/26913
Origin: RepositóriUM - Universidade do Minho
Subject(s): Biomineralization; Layer-by-layer; Sulfated polysaccharides
Description
Publicado em "Journal of Tissue Engineering and Regenerative Medicine", vol. 7, supp. 1 (2013) In vitro cell expansion, differentiation for further cell transplantation
and biomaterials-cell fundamental assays are still performed more often
on inert 2D surfaces than on 3D culture. 3D systems do not allow an
easy cell monitoring and may demand higher cell density, being more
costly and time consuming. Inert surfaces (polystyrene, biodegradable
thermoplastics or metals) neither resemble the extracellular matrix
(ECM) milieu nor trigger intercellular signaling. Several studies are
focused on surface modification and on the correlation of the surface
properties such as roughness, wettability and chemistry with cell
behavior with regard to the effects on cell adhesion, morphology, proliferation,
survival and differentiation.1,2 Proteins, hormones, small peptides,
cytokines, inorganic molecules, sulfated and non-polysaccharides
(PS) compose the natural 3D ECM milieu. PS vary on the sulfur content,
sulfonic group (Sg) position and on base units. Sulfonated and
sulfated PS have intrinsic very high affinity towards growth factors and
positively charged molecules through the functional groups turning the
combination of themvery bioactive hybrids mats. Current surface modification
models make the transposition to 3D systems complicate.
Layer-by-Layer (LbL) assembling is a versatile technique to coat any
2D/3D structure with polyelectrolytes (PE) which coatings properties
can be modelled and controlled. Herein, LbL was employed to develop
2D models to verify the ability of sulfated and aminated coatings to
improve cell function using PS form marine origin: chitosan (Chi) and
carrageenans (Cars). Chi and Cars have equivalent functional groups to
the ones that are naturally found in the ECM: -NH2, -OSO3H, and -OH.
CHI and j, ι and k Car (1, 2 and 3 Sg, respectively) nanocoatings were
assessed by QCM-D, modelled by the Voigt-model, and characterized
by AFM, SEM and XPS3. The properties of the multilayers can be controlled
as well the relative amount of the positive versus the negative
PE. Moreover, the effects on biomineralization of SaOs-2 cell line were
investigated. The coatings, specially ι Car coatings, increased significantly
alkaline phosphatase activity and biomineralization of SaOs-2
cell line. The results indicated that the coatings do not only attract
medium ions but also enhance osteogenic cell function. These models
are interesting to study cell-materials interactions where surfaces culture
with increased biofunctionality can be developed.
