Autor(es):
Correia, Joana Silva 
; Zavan, B. ; Vindigni, V. ; Oliveira, M. B. ; Mano, J. F. ; Pereira, H. ; Oliveira, Joaquim M. ; Mendes, João Espregueira ; Abatangelo, G. ; Reis, R. L.
Data: 2012
Identificador Persistente: http://hdl.handle.net/1822/23147
Origem: RepositóriUM - Universidade do Minho
Assunto(s): Biocompatibility in vivo; Methacrylated gellan gum
Descrição
Methacrylated gellan gum hydrogels, obtained either by ionic- (iGGMA)
and photo-crosslinking (phGG-MA), have been investigated as
potential biomaterials for supporting nucleus pulposus (NP) regeneration
and/or repair [1,2]. In previous work, some advantages were
attributed to GG-MA hydrogels, such as: (i) the possibility to control
endothelial cells infiltration and blood vessel ingrowth’s, (ii) tunable
and improved mechanical properties, and (iii) in situ gelation, within
seconds to few minutes. In this study, the mechanical and biological
performance of these hydrogels was firstly evaluated in vitro. Human
intervertebral disc (hIVD) cells obtained from herniated patients were
cultured within both hydrogels, for 1 up to 21 days. Dynamic mechanical
analysis and biological characterization (calcein-AM staining, ATP
and DNA quantification and PCR) were performed after specific times
of culturing. A biocompatibility study was also performed in vivo, by
subcutaneous implantation of acellular iGG-MA and phGG-MA hydrogels
in Lewis rats for the period of 10 and 18 days. Tissue response to
the hydrogels implantation was determined by histological analysis
(haematoxylin-eosin staining). The in vitro study showed that both cell
loading and culturing time do not have an effect on the mechanical
properties of the hydrogels. Regarding their biological performance,
the iGG-MA and phGG-MA hydrogels showed to be effective on supporting
hIVD cells encapsulation and viability up to 21 days of culturing.
Human IVD cells were homogeneously distributed within the
hydrogels and maintained its round-shape morphology during culturing
time. The in vivo biocompatibility study showed that iGG-MA and
phGG-MA hydrogels do not elicit any deleterious effect, as denoted by
the absence of necrosis and calcification, or acute inflammatory reaction.
A thin fibrous capsule was observed around the implanted hydrogels.
The results presented in this study indicate that the iGG-MA and
phGG-MA hydrogels are stable in vitro and in vivo, support hIVD cells
encapsulation and viability, and were found to be well-tolerated and
non-cytotoxic in vivo, thus being potential candidates for NP regeneration.
