In vitro3D culture of human chondrocytes using modifiedε-caprolactone scaffolds with varying hydrophilicity and porosity

Abstract

Two series of 3D scaffolds based on ε-caprolactone were synthesized. The pore size and architecture (spherical interconnected pores) was the same in all the scaffolds. In one of the series of scaffolds, made of pure ε-polycaprolactone, the volume fraction of pores varied between 60% and 85% with the main consequence of varying the interconnectivity between pores since the pore size was kept constant. The other scaffolds were prepared with copolymers made of a ε-caprolactone-based hydrophobous monomer and hydroxyethyl acrylate, as the hydrophilic component. Thus, the hydrophilicity and, presumably, the adhesion properties varied monotonously in the copolymer series while porosity was kept constant. A suspension of human chondrocytes in culture medium was injected in the 3D scaffolds and cultured in static conditions up to 28 days. SEM and immunofluorescence assays allowed characterizing cells and extracellular matrix inside the scaffolds after different culture times. To do that, cross sections of the scaffolds were observed by SEM and confocal microscopy. The quantity of cells inside the scaffolds decreases with a decrease of the volume fraction of pores, due to the lack of interconnectivity between the cavities. The scaffolds up to a 30% of hydrophilicity behave in a similar way than the hydrophobous; a further increase of the hydrophilicity rapidly decreases cell viability. In all the experiments production of collagen type I, type II, and aggrecan was found, and some cells were Ki-67 positive, showing that some cells are adhered to the pore walls and maintain their dedifferentiated phenotype even when cultured in three-dimensional conditions.

In vitromechanical fatigue behavior of poly‐ɛ‐caprolactone macroporous scaffolds for cartilage tissue engineering: Influence of pore filling by a poly(vinyl alcohol) gel

“…Such structure favors scaffold permeability to nutrients and waste products of cell metabolism and can be used to retain active components 11,33,34 . However, apparent scaffold stiffness becomes smaller than in similar sponges lacking microporosity 13,35 .…”

Fatigue prediction in fibrin poly-ε-caprolactone macroporous scaffolds

“…Microporosity favors permeability of the scaffold to nutrients and waste products of cell metabolism and can be used to retain different active components (Deplaine et al, 2010;Lebourg et al, 2010a;Lebourg et al, 2010b). Nevertheless, http://www.sciencedirect.com/science/article/pii/S1751616113002427 7 the apparent stiffness of the scaffold becomes significantly smaller than in similar sponges lacking microporosity, also used in cartilage engineering (Martinez-Diaz et al, 2010;Olmedilla et al, 2012).…”

“…Dry samples has a maximum stress almost two times higher than immersed ones, this behavior is probably related to the small amount of water absorbed by the PCL polymer (Olmedilla et al, 2012) that consequently act as plasticizer, contributing for material softening (figure 2c).…”

Bioactive organic–inorganic poly(CLMA-co-HEA)/silica nanocomposites

“…1,3 An adequate hydrophobic/hydrophilic balance in synthetic materials is fundamental for cell adhesion, proliferation, differentiation and extracellular matrix production, which depend strongly on the hydrophilicity of the substrate. 4,5 In general, high hydrophilic character reduces cell adhesion on the substrate and intermediate hydrophilicity promotes it. 5 Our previous works demonstrated that P(CLMA-co-HEA) networks with intermediate hydrophilicity (with around a 30 wt% of HEA) are the best candidates in this system for the culture of bone marrow stromal cells 2 and human chondrocytes 5 in terms of cell adhesion, proliferation and differentiation.…”

“…4,5 In general, high hydrophilic character reduces cell adhesion on the substrate and intermediate hydrophilicity promotes it. 5 Our previous works demonstrated that P(CLMA-co-HEA) networks with intermediate hydrophilicity (with around a 30 wt% of HEA) are the best candidates in this system for the culture of bone marrow stromal cells 2 and human chondrocytes 5 in terms of cell adhesion, proliferation and differentiation.…”