Descrição
Native bone extracellular matrix (ECM) is a complex hierarchical fibrous composite structure, resulting from the
assembling of collagen fibrils at several length scales, ranging from the macro to the nanoscale. The combination
of nanofibers within microfibers after conventional reinforcement methodologies seems to be a feasible solution
to the rational design of highly functional synthetic ECM substitutes. The present work aims at the development
of bone ECM inspired structures, conjugating electrospun chitosan (Cht) nanofibers within biodegradable
polymeric microfibers [poly(butylene succinate)—PBS and PBS/Cht], assembled in a fiber mesh structure. The
nanofibers-reinforced composite fiber mesh scaffolds were seeded with human bone marrow mesenchymal stem
cells (hBMSCs) and cultured under osteogenic differentiation conditions. These nanofibers-reinforced composite
scaffolds sustained ECM deposition and mineralization, mainly in the PBS/Cht-based fiber meshes, as depicted
by the increased amount of calcium phosphates produced by the osteogenic differentiated hBMSCs. The osteogenic
genotype of the cultured hBMSCs was confirmed by the expression of osteoblastic genes, namely Alkaline
Phosphatase, Osteopontin, Bone Sialoprotein and Osteocalcin, and the transcription factors Runx2 and Osterix, all
involved in different stages of the osteogenesis. These data represent the first report on the biological functionality
of nanofibers-reinforced composite scaffolds, envisaging the applicability of the developed structures
for bone tissue engineering.
; Pinho, Elisabete D. 
