Modulating microfibrillar alignment and growth factor stimulation to regulate mesenchymal stem cell differentiation

Abstract

The ideal tissue engineering (TE) strategy for ligament regeneration should recapitulate the bonecalcified cartilage -fibrocartilage -soft tissue interface. Aligned electrospun-fibers have been shown to guide the deposition of a highly organized extracellular matrix (ECM) necessary for ligament TE.However, recapitulating the different tissues observed in the bone-ligament interface using such constructs remains a challenge. This study aimed to explore how fiber alignment and growth factor stimulation interact to regulate the chondrogenic and ligamentous differentiation of mesenchymal stem cells (MSCs). Without growth factor stimulation, MSCs on aligned-microfibers showed higher levels of tenomodulin (TNMD) and aggrecan gene expression compared to MSCs on randomlyoriented fibers. MSCs on aligned-microfibers stimulated with transforming growth factor β3 (TGFβ3) formed cellular aggregates and underwent robust chondrogenesis, evidenced by increased type II collagen expression and sulphated glycosaminoglycans (sGAG) synthesis compared to MSCs on randomly-oriented scaffolds. Bone morphogenetic protein 2 (BMP2) and type I collagen gene expression were higher on randomly-oriented scaffolds stimulated with TGFβ3, suggesting this substrate was more supportive of an endochondral phenotype. In the presence of connective tissue growth factor (CTGF), MSCs underwent ligamentous differentiation, with increased TNMD expression on aligned compared to randomly aligned scaffolds. Upon sequential growth factor stimulation, MSCs expressed types I and II collagen and deposited higher overall levels of collagen compared to scaffolds stimulated with either growth factor in isolation. These findings demonstrate that modulating the alignment of microfibrillar scaffolds can be used to promote either an endochondral, chondrogenic, fibro-chondrogenic or ligamentous MSC phenotype upon presentation of appropriate biochemical cues.

Biofabrication of Electrospun Scaffolds for the Regeneration of Tendons and Ligaments

“…Oliveira et al studied the differentiation of bone marrow-derived porcine mesenchymal stem cells in ligament or bone/cartilage differentiation, using random and aligned microfibers of PCL. They added different growth factors to study the differentiation of cells in ligamentogenic, chondrogenic or fibrochondrogenic phenotype upon presentation of appropriate biochemical cues [ 90 ]. Wu et al focused on the repair of the tendon-to-bone and ligament-to-bone insertions: they analyzed nanostructured HAp, loaded in random nanofibrous blends mats of PCL and CTS.…”

Isolation and characterization of stem cells from differentially degenerated human lumbar zygapophyseal articular cartilage

“…Cytoskeleton staining revealed fibrosis in the stem cells isolated from mildly and severely degenerated LZAC, indicating that the mesochondrial environment altered the characteristics of these cells to some extent (30,31). Subsequent experiments suggested that stem cells isolated from mildly degenerated LZAC exhibited enhanced chondrogenic differentiation and clonogenic abilities compared with those from normal LZAC.…”

Combined Influence of Gelatin Fibre Topography and Growth Factors on Cultured Dorsal Root Ganglia Neurons

“…Additionally, the introduction of biochemical cues on biomaterial surface is a successful way to efficiently induce specific cell behavior such as cell survival, cell differentiation or cell growth (Li and Folch, ; Krick et al, ). The stimulation with growth factors combined with fibre substrate has demonstrated its efficacy for different biological processes, among which nerve regeneration (Bruggeman et al, ; Olvera et al, ), and specific growth factors might be used to guide the axonal growth of specific neuron population. Here, we tested individually several growth factors, whose receptors are expressed in different sensory neuron populations.…”