Autor(es):
Martins, Ana M. 
; Kretlow, J. D. ; Pinto, A. R. ; Malafaya, P. B. ; Fernandes, E. M. ; Neves, N. M. ; Alves, Catarina M. ; Mikos, Antonios G. ; Kasper, F. Kurtis ; Reis, R. L.
Data: 2012
Identificador Persistente: http://hdl.handle.net/1822/23149
Origem: RepositóriUM - Universidade do Minho
Assunto(s): Enzymes; In situ pore formation; In vivo degradation; Natural origin materials; Tissue response
Descrição
This study used a rat subcutaneous implantation
model to investigate gradual in situ pore formation in a
self-regulating degradable chitosan-based material, which
comprises lysozyme incorporated into biomimetic calcium
phosphate (CaP) coatings at the surface to control the scaffold
degradation and subsequent pore formation. Specifically, the
in vivo degradation of the scaffolds, the in situ pore formation,
and the tissue response were investigated. Chitosan or
chitosan/starch scaffolds were studied with and without a CaP
coating in the presence or absence of lysozyme for a total of
six experimental groups. Twenty-four scaffolds per group
were implanted, and eight scaffolds were retrieved at each of
three time points (3, 6, and 12 weeks). Harvested samples were
analyzed for weight loss, microcomputed tomography, and histological analysis. All scaffolds showed pronounced weight
loss and pore formation as a function of time. The highest
weight loss was 29.8% 6 1.5%, obtained at week 12 for CaP
chitosan/starch scaffolds with lysozyme incorporated. Moreover,
all experimental groups showed a significant increase in porosity
after 12 weeks. At all time points no adverse tissue reaction
was observed, and as degradation increased, histological
analysis showed cellular ingrowth throughout the implants.
Using this innovative methodology, the ability to gradually generate
pores in situ was clearly demonstrated in vivo.
