Description
This work proposes the use of nonporous, smart, and stimulus responsive chitosan-based scaffolds for bone
tissue engineering applications. The overall vision is to use biodegradable scaffolds based on chitosan and starch
that present properties that will be regulated by bone regeneration, with the capability of gradual in situ pore
formation. Biomimetic calcium phosphate (CaP) coatings were used as a strategy to incorporate lysozyme at the
surface of chitosan-based materials with the main objective of controlling and tailoring their degradation profile
as a function of immersion time. To confirm the concept, degradation tests with a lysozyme concentration similar
to that incorporated into CaP chitosan-based scaffolds were used to study the degradation of the scaffolds and
the formation of pores as a function of immersion time. Degradation studies with lysozyme (1.5 g=L) showed the
formation of pores, indicating an increase of porosity (*5–55% up to 21 days) resulting in porous threedimensional
structures with interconnected pores. Additional studies investigated the influence of a CaP
biomimetic coating on osteogenic differentiation of rat marrow stromal cells (MSCs) and showed enhanced
differentiation of rat MSCs seeded on the CaP-coated chitosan-based scaffolds with lysozyme incorporated.
At all culture times, CaP-coated chitosan-based scaffolds with incorporated lysozyme demonstrated greater
osteogenic differentiation of MSCs, bone matrix production, and mineralization as demonstrated by calcium
deposition measurements, compared with controls (uncoated scaffolds). The ability of these CaP-coated
chitosan-based scaffolds with incorporated lysozyme to create an interconnected pore network in situ coupled
with the demonstrated positive effect of these scaffolds upon osteogenic differentiation of MSCs and mineralized
matrix production illustrates the strong potential of these scaffolds for application in bone tissue engineering
strategies.
; Pham, Q. P. 
