Author(s):
Yan, Leping 
; Correia, Cristina ; Correia, Joana Silva ; Caridade, S. G. ; Fernandes, E. M. ; Mano, J. F. ; Sousa, R. A. ; Oliveira, Joaquim M. ; Oliveira, A. L. ; Reis, R. L.
Date: 2012
Persistent ID: http://hdl.handle.net/1822/24081
Origin: RepositóriUM - Universidade do Minho
Subject(s): Bone; Silk fibroin
Description
Macro/micro porous silk scaffolds with nano-sized calcium phosphate
(CaP) particles were developed for bone tissue engineering. Different
amounts of nano-sized CaP particles 4, 8, 16 and 25% (CaP:silk
fibroin, wt/wt) were generated into the highly concentrated aqueous
silk fibroin solutions via an in-situ approach. Afterwards, the pure
silk and silk/nano-CaP porous scaffolds were produced by a combination
of salt-leaching/freeze-drying methods. Thermal gravimetric
analysis results were able to demonstrated that the silk/nano-CaP
scaffolds maintained 64–87% of incorporated CaP after salt-leaching.
Dynamic mechanical analysis showed that storage modulus of the
16% formulation was significantly higher than all remaining groups.
The porosity of silk/nano-CaP scaffolds assessed using Micro-Computed
Tomography decreased from 79.8% to 63.6% with increasing
CaP incorporated until 16%. By soaking the scaffolds in Simulated
Body Fluid for 7 days, cauliflower-like apatite clusters were observed
on the surface of both macro and micro pores of 16% and 25% formulations,
which was not observed in 4 and 8% formulations. 16%
silk/nano-CaP scaffolds were further chosen for in vitro cytotoxicity
and biocompatibility assays. Both silk and 16% silk/nano-CaP scaffolds
were non-cytotoxic and promoted cell adhesion and proliferation
to a similar extent. These results indicated that the 16% silk/
nano-CaP scaffolds could be a good candidate for bone tissue
engineering.
