TY  - JOUR
AU  - Obradović, Bojana
AU  - Martin, Ivan
AU  - Padera, RF
AU  - Treppo, S
AU  - Freed, LE
AU  - Vunjak-Novaković, Gordana
PY  - 2001
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/371
AB  - The structure and function of cartilaginous constructs, engineered in vitro using bovine articular chondrocytes, biodegradable scaffolds and bioreactors, can be modulated by the conditions and duration of tissue cultivation. We hypothesized that the integrative properties of engineered cartilage depend on developmental stage of the construct and the extracellular matrix content of adjacent cartilage, and that some aspects of integration can be studied under controlled in vitro conditions. Disc-shaped constructs (cultured for 5 +/- 1 days or 5 +/- 1 weeks) or explants (untreated or trypsin treated cartilage) were sutured into ring-shaped explants (untreated or trypsin treated cartilage) to form composites that were cultured for an additional 1-8 weeks in bioreactors and evaluated biochemically, histologically and mechanically (compressive stiffness of the central disk, adhesive strength of the integration interface). Immature constructs had poorer mechanical properties but integrated better than either more mature constructs or cartilage explants. Integration of immature constructs involved cell proliferation and the progressive formation of cartilaginous tissue, in contrast to the integration of more mature constructs or native cartilage which involved only the secretion of extracellular matrix components. Integration patterns correlated with the adhesive strength of the disc-ring interface, which was markedly higher for immature constructs than for either more mature constructs or cartilage explants. Trypsin treatment of the adjacent cartilage further enhanced the integration of immature constructs.
PB  - Elsevier Sci Ltd, Oxford
T2  - Journal of Orthopaedic Research
T1  - Integration of engineered cartilage
EP  - 1097
IS  - 6
SP  - 1089
VL  - 19
DO  - 10.1016/S0736-0266(01)00030-4
ER  - 

@article{
author = "Obradović, Bojana and Martin, Ivan and Padera, RF and Treppo, S and Freed, LE and Vunjak-Novaković, Gordana",
year = "2001",
abstract = "The structure and function of cartilaginous constructs, engineered in vitro using bovine articular chondrocytes, biodegradable scaffolds and bioreactors, can be modulated by the conditions and duration of tissue cultivation. We hypothesized that the integrative properties of engineered cartilage depend on developmental stage of the construct and the extracellular matrix content of adjacent cartilage, and that some aspects of integration can be studied under controlled in vitro conditions. Disc-shaped constructs (cultured for 5 +/- 1 days or 5 +/- 1 weeks) or explants (untreated or trypsin treated cartilage) were sutured into ring-shaped explants (untreated or trypsin treated cartilage) to form composites that were cultured for an additional 1-8 weeks in bioreactors and evaluated biochemically, histologically and mechanically (compressive stiffness of the central disk, adhesive strength of the integration interface). Immature constructs had poorer mechanical properties but integrated better than either more mature constructs or cartilage explants. Integration of immature constructs involved cell proliferation and the progressive formation of cartilaginous tissue, in contrast to the integration of more mature constructs or native cartilage which involved only the secretion of extracellular matrix components. Integration patterns correlated with the adhesive strength of the disc-ring interface, which was markedly higher for immature constructs than for either more mature constructs or cartilage explants. Trypsin treatment of the adjacent cartilage further enhanced the integration of immature constructs.",
publisher = "Elsevier Sci Ltd, Oxford",
journal = "Journal of Orthopaedic Research",
title = "Integration of engineered cartilage",
pages = "1097-1089",
number = "6",
volume = "19",
doi = "10.1016/S0736-0266(01)00030-4"
}

Obradović, B., Martin, I., Padera, R., Treppo, S., Freed, L.,& Vunjak-Novaković, G.. (2001). Integration of engineered cartilage. in Journal of Orthopaedic Research
Elsevier Sci Ltd, Oxford., 19(6), 1089-1097.
https://doi.org/10.1016/S0736-0266(01)00030-4

Obradović B, Martin I, Padera R, Treppo S, Freed L, Vunjak-Novaković G. Integration of engineered cartilage. in Journal of Orthopaedic Research. 2001;19(6):1089-1097.
doi:10.1016/S0736-0266(01)00030-4 .

Obradović, Bojana, Martin, Ivan, Padera, RF, Treppo, S, Freed, LE, Vunjak-Novaković, Gordana, "Integration of engineered cartilage" in Journal of Orthopaedic Research, 19, no. 6 (2001):1089-1097,
https://doi.org/10.1016/S0736-0266(01)00030-4 . .

TY  - JOUR
AU  - Martin, Ivan
AU  - Obradović, Bojana
AU  - Treppo, S
AU  - Grodzinsky, AJ
AU  - Langer, R
AU  - Freed, LE
AU  - Vunjak-Novaković, Gordana
PY  - 2000
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/298
AB  - Cartilaginous constructs have been grown in vitro using chondrocytes, biodegradable polymer scaffolds, and tissue culture bioreactors. In the present work, we studied how the composition and mechanical properties of engineered cartilage can be modulated by the conditions and duration of in vitro cultivation, using three different environments: static flasks, mixed flasks, and rotating vessels. After 4-6 weeks, static culture yielded small and fragile constructs, while turbulent flow in mixed flasks induced the formation of an outer fibrous capsule; both environments resulted in constructs with poor mechanical properties. The constructs that were cultured freely suspended in a dynamic laminar flow field in rotating vessels had the highest fractions of glycosaminoglycans and collagen (respectively 75% and 39% of levels measured in native cartilage), and the best mechanical properties (equilibrium modulus, hydraulic permeability, dynamic stiffness, and streaming potential were all about 20% of values measured in native cartilage). Chondrocytes in cartilaginous constructs remained metabolically active and phenotypically stable over prolonged cultivation in rotating bioreactors. The wet weight fraction of glycosaminoglycans and equilibrium modulus of 7 month constructs reached or exceeded the corresponding values measured from freshly explanted native cartilage. Taken together, these findings suggest that functional equivalents of native cartilage can be engineered by optimizing the hydrodynamic conditions in tissue culture bioreactors and the duration of tissue cultivation.
PB  - IOS Press, Amsterdam
T2  - Biorheology
T1  - Modulation of the mechanical properties of tissue engineered cartilage
EP  - 147
IS  - 1-2
SP  - 141
VL  - 37
UR  - https://hdl.handle.net/21.15107/rcub_technorep_298
ER  - 

@article{
author = "Martin, Ivan and Obradović, Bojana and Treppo, S and Grodzinsky, AJ and Langer, R and Freed, LE and Vunjak-Novaković, Gordana",
year = "2000",
abstract = "Cartilaginous constructs have been grown in vitro using chondrocytes, biodegradable polymer scaffolds, and tissue culture bioreactors. In the present work, we studied how the composition and mechanical properties of engineered cartilage can be modulated by the conditions and duration of in vitro cultivation, using three different environments: static flasks, mixed flasks, and rotating vessels. After 4-6 weeks, static culture yielded small and fragile constructs, while turbulent flow in mixed flasks induced the formation of an outer fibrous capsule; both environments resulted in constructs with poor mechanical properties. The constructs that were cultured freely suspended in a dynamic laminar flow field in rotating vessels had the highest fractions of glycosaminoglycans and collagen (respectively 75% and 39% of levels measured in native cartilage), and the best mechanical properties (equilibrium modulus, hydraulic permeability, dynamic stiffness, and streaming potential were all about 20% of values measured in native cartilage). Chondrocytes in cartilaginous constructs remained metabolically active and phenotypically stable over prolonged cultivation in rotating bioreactors. The wet weight fraction of glycosaminoglycans and equilibrium modulus of 7 month constructs reached or exceeded the corresponding values measured from freshly explanted native cartilage. Taken together, these findings suggest that functional equivalents of native cartilage can be engineered by optimizing the hydrodynamic conditions in tissue culture bioreactors and the duration of tissue cultivation.",
publisher = "IOS Press, Amsterdam",
journal = "Biorheology",
title = "Modulation of the mechanical properties of tissue engineered cartilage",
pages = "147-141",
number = "1-2",
volume = "37",
url = "https://hdl.handle.net/21.15107/rcub_technorep_298"
}

Martin, I., Obradović, B., Treppo, S., Grodzinsky, A., Langer, R., Freed, L.,& Vunjak-Novaković, G.. (2000). Modulation of the mechanical properties of tissue engineered cartilage. in Biorheology
IOS Press, Amsterdam., 37(1-2), 141-147.
https://hdl.handle.net/21.15107/rcub_technorep_298

Martin I, Obradović B, Treppo S, Grodzinsky A, Langer R, Freed L, Vunjak-Novaković G. Modulation of the mechanical properties of tissue engineered cartilage. in Biorheology. 2000;37(1-2):141-147.
https://hdl.handle.net/21.15107/rcub_technorep_298 .

Martin, Ivan, Obradović, Bojana, Treppo, S, Grodzinsky, AJ, Langer, R, Freed, LE, Vunjak-Novaković, Gordana, "Modulation of the mechanical properties of tissue engineered cartilage" in Biorheology, 37, no. 1-2 (2000):141-147,
https://hdl.handle.net/21.15107/rcub_technorep_298 .

TY  - JOUR
AU  - Vunjak-Novaković, Gordana
AU  - Martin, Ivan
AU  - Obradović, Bojana
AU  - Treppo, S
AU  - Grodzinsky, AJ
AU  - Langer, R
AU  - Freed, LE
PY  - 1999
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/243
AB  - Cartilaginous constructs have been grown in vitro with use of isolated cells, biodegradable polymer scaffolds, and bioreactors. In the present work, the relationships between the composition and mechanical properties of engineered cartilage constructs were studied by culturing bovine calf articular chondrocytes on fibrous polyglycolic acid scaffolds (5 mm in diameter, 2-mm thick, and 97% porous) in three different environments: static flasks, mixed flasks, and rotating vessels. After 6 weeks of cultivation, the composition, morphology, and mechanical function of the constructs in radially confined static and dynamic compression all depended on the conditions of in vitro cultivation. Static culture yielded small and fragile constructs, while turbulent flow in mixed flasks yielded constructs with fibrous outer capsules; both environments resulted in constructs with poor mechanical properties. The constructs that were cultured freely suspended in a dynamic laminar flow field in rotating vessels were the largest, contained continuous cartilage-like extracellular matrices with the highest fractions of glycosaminoglycan and collagen, and had the best mechanical properties. The equilibrium modulus, hydraulic permeability, dynamic stiffness, and streaming potential correlated with the wet-weight fractions of glycosaminoglycan, collagen, and water. These findings suggest that the hydrodynamic conditions in tissue-culture bioreactors can modulate the composition, morphology, mechanical properties, and electromechanical function of engineered cartilage.
PB  - Wiley, Hoboken
T2  - Journal of Orthopaedic Research
T1  - Bioreactor cultivation conditions modulate the composition and mechanical properties of tissue-engineered cartilage
EP  - 138
IS  - 1
SP  - 130
VL  - 17
DO  - 10.1002/jor.1100170119
ER  - 

@article{
author = "Vunjak-Novaković, Gordana and Martin, Ivan and Obradović, Bojana and Treppo, S and Grodzinsky, AJ and Langer, R and Freed, LE",
year = "1999",
abstract = "Cartilaginous constructs have been grown in vitro with use of isolated cells, biodegradable polymer scaffolds, and bioreactors. In the present work, the relationships between the composition and mechanical properties of engineered cartilage constructs were studied by culturing bovine calf articular chondrocytes on fibrous polyglycolic acid scaffolds (5 mm in diameter, 2-mm thick, and 97% porous) in three different environments: static flasks, mixed flasks, and rotating vessels. After 6 weeks of cultivation, the composition, morphology, and mechanical function of the constructs in radially confined static and dynamic compression all depended on the conditions of in vitro cultivation. Static culture yielded small and fragile constructs, while turbulent flow in mixed flasks yielded constructs with fibrous outer capsules; both environments resulted in constructs with poor mechanical properties. The constructs that were cultured freely suspended in a dynamic laminar flow field in rotating vessels were the largest, contained continuous cartilage-like extracellular matrices with the highest fractions of glycosaminoglycan and collagen, and had the best mechanical properties. The equilibrium modulus, hydraulic permeability, dynamic stiffness, and streaming potential correlated with the wet-weight fractions of glycosaminoglycan, collagen, and water. These findings suggest that the hydrodynamic conditions in tissue-culture bioreactors can modulate the composition, morphology, mechanical properties, and electromechanical function of engineered cartilage.",
publisher = "Wiley, Hoboken",
journal = "Journal of Orthopaedic Research",
title = "Bioreactor cultivation conditions modulate the composition and mechanical properties of tissue-engineered cartilage",
pages = "138-130",
number = "1",
volume = "17",
doi = "10.1002/jor.1100170119"
}

Vunjak-Novaković, G., Martin, I., Obradović, B., Treppo, S., Grodzinsky, A., Langer, R.,& Freed, L.. (1999). Bioreactor cultivation conditions modulate the composition and mechanical properties of tissue-engineered cartilage. in Journal of Orthopaedic Research
Wiley, Hoboken., 17(1), 130-138.
https://doi.org/10.1002/jor.1100170119

Vunjak-Novaković G, Martin I, Obradović B, Treppo S, Grodzinsky A, Langer R, Freed L. Bioreactor cultivation conditions modulate the composition and mechanical properties of tissue-engineered cartilage. in Journal of Orthopaedic Research. 1999;17(1):130-138.
doi:10.1002/jor.1100170119 .

Vunjak-Novaković, Gordana, Martin, Ivan, Obradović, Bojana, Treppo, S, Grodzinsky, AJ, Langer, R, Freed, LE, "Bioreactor cultivation conditions modulate the composition and mechanical properties of tissue-engineered cartilage" in Journal of Orthopaedic Research, 17, no. 1 (1999):130-138,
https://doi.org/10.1002/jor.1100170119 . .