Regeneration of Achilles' tendon: the role of dynamic stimulation for enhanced cell proliferation and mechanical properties.
The tissue engineering of tendon was studied using highly elastic poly(L-lactide-co-epsilon-caprolactone) (PLCL) scaffolds and focusing on the effect of dynamic tensile stimulation. Tenocytes from rabbit Achilles tendon were seeded (1.0 x 10(6) cells/scaffold) onto porous PLCL scaffolds and cultured for periods of 2 weeks and 4 weeks. This was performed in a static system and also in a bioreactor equipped with tensile modulation which mimicked the environmental surroundings of tendons with respect to tensile extension. The degradation of the polymeric scaffolds during the culture was relatively slow. However, there was an indication that cells accelerated the degradation of PLCL scaffolds. The scaffold/cell adducts from the static culture exhibited inferior strength (at 2 weeks 350 kPa, 4 weeks 300 kPa) compared to the control without cells (at 2 weeks 460 kPa, 4 weeks 340 kPa), indicating that the cells contributed to the enhanced degradation. On the contrary, the corresponding values of the adducts from the dynamic culture (at 2 weeks 430 kPa, 4 weeks 370 kPa) were similar to, or higher than, those from the control. This could be explained by the increased quantity of cells and neo-tissues in the case of dynamic culture compensating for the loss in tensile strength. Compared with static and dynamic culture conditions, mechanical stimulation played a crucial role in the regeneration of tendon tissue. In the case of the dynamic culture system, cell proliferation was enhanced and secretion of collagen type I was increased, as evidenced by DNA assay and histological and immunofluorescence analysis. Thus, tendon regeneration, indicated by improved mechanical and biological properties, was demonstrated, confirming the effect of mechanical stimulation. It could be concluded that the dynamic tensile stimulation appeared to be an essential factor in tendon/ligament tissue engineering, and that elastic PLCL co-polymers could be very beneficial in this process.
Lee
Jongman
J
Department of Materials Science and Engineering, Research Center for Biomolecular Nanotechnology, Gwangju Institute of Science and Technology, Gwangju 500-712, South Korea.
Guarino
Vincenzo
V
Gloria
Antonio
A
Ambrosio
Luigi
L
Tae
Giyoong
G
Kim
Young Ha
YH
Jung
Youngmee
Y
Kim
Sang-Heon
SH
Kim
Soo Hyun
SH
D000125:Achilles Tendon / Q000166:cytology* / Q000187:drug effects / Q000502:physiology*; D000818:Animals; D001696:Biomechanical Phenomena; D032701:Biomimetics; D018929:Cell Culture Techniques; D049109:Cell Proliferation / Q000187:drug effects; D005109:Extracellular Matrix / Q000187:drug effects / Q000378:metabolism; D005455:Fluorescent Antibody Technique; D008022:Ligaments / Q000166:cytology / Q000502:physiology; D055595:Mechanical Phenomena; D008855:Microscopy, Electron, Scanning; D011091:Polyesters / Q000737:chemistry / Q000494:pharmacology; D016062:Porosity; D011817:Rabbits; D012038:Regeneration / Q000187:drug effects; D013718:Tensile Strength; D023822:Tissue Engineering; D054457:Tissue Scaffolds / Q000737:chemistry
D011091:Polyesters; C062968:lactide-caprolactone copolymer