Descrição
Bone extracellular matrix (ECM) is composed of mineralized collagen fibrils which support biological
apatite nucleation that participates in bone outstanding properties. Understanding and mimicking
bone morphological and physiological parameters at a biological scale is a major challenge in tissue
engineering scaffolding. Using emergent (nano)technologies scaffold designing may be critically
improved, enabling highly functional tissue substitutes for bone applications. This study aims to develop
novel biodegradable composite scaffolds of tricalcium phosphate (TCPs) and electrospun nanofibers
of poly(e-caprolactone) (PCL), combining TCPs osteoconductivity with PCL biocompatibility
and elasticity, mimicking bone structure and composition. We hypothesized that scaffolds with such
structure/composition would stimulate the proliferation and differentiation of bone marrow stromal
cells (BMSCs) towards the osteogenic phenotype. Composite scaffolds, developed by electrospining
using consecutive stacked layers of PCL and TCPs, were characterized by FTIR spectroscopy, X-Ray diffraction
and scanning electronic microscopy. Cellular behavior was assessed in goat BMSCs seeded
onto composite scaffolds and cultured in static or dynamic conditions, using basal or osteogenic media
during 7, 14 or 21 days. Cellular proliferation was quantified and osteogenic differentiation confirmed
by alkaline phosphatase activity, alizarin red staining and immunocytochemistry for osteocalcin and
collagen I. Results suggest that PCL-TCP scaffolds provide a 3D support for gBMSCs proliferation
and osteogenic differentiation with production of ECM. TCPs positively stimulate the osteogenic
process, especially under dynamic conditions, where PCL-TCP scaffolds are sufficient to promote
osteogenic differentiation even in basal medium conditions. The enhancement of the osteogenic
potential in dynamic conditions evidences the synergistic effect of scaffold composition and dynamic
stimulation in gBMSCs osteogenic differentiation.
; Martins, Albino 
