Affiliations: Laboratory of Biological Structure Mechanics, Politecnico di Milano, Milano, Italy | Simple Structure of Tissue Therapy, Niguarda Cà Granda Hospital, Milano, Italy | Biomedical Engineering Laboratory, Mario Negri Institute for Pharmacological Research, Bergamo, Italy
Note: [] Address for correspondence: Manuela Teresa Raimondi, PhD, Dipartimento di Bioingegneria, Politecnico Di Milano, Piazza Leonardo da Vinci, 32, 20133 Milano, Italy. Tel.: +39 02 2399 3349; Fax: +39 02 2399 3360; E‐mail: [email protected].
Abstract: This work examines the effect of perfusion on human mature articular chondrocytes cultured on synthetic biodegradable scaffolds (DegraPol). Human chondrocytes were isolated, seeded on the scaffolds and subjected to perfused culture at a flow rate of 0.5 ml/min, corresponding to an average inlet fluid velocity of 44 μm/s, with flow inversion every 1 minute. The flow was imposed at the construct surface in some constructs, it was forced through the construct thickness in other constructs and was absent in the static controls. We compared cell viability and morphology and we evaluated material properties of the constructs at 1 month of culture. Thickness‐perfused constructs showed significantly higher material properties and roughly a two‐fold cell viability, when compared both to surface‐perfused constructs and to static controls. Chondrocytes maintained a phenotypic morphology in all experiments, probably favoured by a limited cell–scaffold interaction. Biosynthetic activity could be demonstrated only in the bioreactor‐cultured constructs. In this experimental model, a bi‐directional flow of culture medium was applied to the cells at a macroscopic level and computational modelling was used to quantify the fluid‐dynamic environment induced on the cells at a microscopic level. This method may be used to quantify the effects of fluid‐dynamic shear on the growth modulation of tissue‐engineered cartilage constructs, to potentially enhance tissue growth in vitro.
