Enhancement of tibial regeneration in a rat model by adipose-derived stromal cells in a PLGA scaffold.
BACKGROUND
Autologous adipose-derived stromal cells (ASCs) are an obvious source of osteogenic cells and can be easily isolated from adipose tissue. We evaluated the potential of ASCs seeded onto a scaffold to heal tibial defects.


METHODS
Autologous ASCs were obtained from adipose tissue by collagenase digestion. The cells were seeded in three-dimensional poly(lactic)-glycolic acid (PLGA) scaffolds and cultured in osteogenic medium for four weeks. Evidence of osteogenesis was assessed by von Kossa staining in three-dimensional cultures following osteogenic induction. The critical size tibial defects (10mm) were created using a rat model. Defects were either left empty (sham group), treated with a PLGA scaffold alone (PLGA group), or a PLGA/ASC composite (PLGA/ASC group). Using radiologic and histologic analyses, we assessed total bone volume and vascular density. Total RNA was prepared from regenerated bone and analyzed for osteogenic marker gene expression.


RESULTS
In three-dimensional cultures, the PLGA/ASC composite showed multiple calcified extracellular matrix nodules on von Kossa staining after four weeks of differentiation. Near complete healing was observed between the PLGA/ASC engrafted tibial defects on plain radiographs and micro-CT findings. Total bone volume and mechanical strength were significantly higher in the PLGA/ASC group compared to the sham and PLGA groups. Histologic analysis revealed increased new bone formation along capillaries in the PLGA/ASC group. Real-time RT-PCR analysis revealed a significant increase in the expression of osteogenic genes in the PLGA/ASC group.


CONCLUSIONS
The results showed that the repair of tibial defects was accelerated by implantation of autologous ASCs seeded onto a PLGA scaffold. Therefore, PLGA/ASC is a promising new cell-based therapy for healing critical size tibial defects.
Department of Biochemistry, Chonbuk National University Medical School, 567 Baekje-daero, Deokjin-gu, Jeonju, Jeonbuk 561-756, Republic of Korea.
Byung-Hyun
BH
Park
Lu
L
Zhou
Kyu Yun
KY
Jang
Ho Sung
HS
Park
Jung Min
JM
Lim
Sun Jung
SJ
Yoon
Sang Yong
SY
Lee
Jung Ryul
JR
Kim
D000273:Adipose Tissue / Q000166:cytology*; D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D001696:Biomechanical Phenomena / Q000187:drug effects; D001861:Bone Regeneration / Q000187:drug effects*; D002478:Cells, Cultured; D005786:Gene Expression Regulation / Q000187:drug effects; D007150:Immunohistochemistry; D019344:Lactic Acid / Q000494:pharmacology*; D008297:Male; D023421:Models, Animal; D015675:Osteocalcin / Q000378:metabolism; D010012:Osteogenesis / Q000187:drug effects / Q000235:genetics; D011100:Polyglycolic Acid / Q000494:pharmacology*; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011817:Rabbits; D051381:Rats; D017207:Rats, Sprague-Dawley; D060888:Real-Time Polymerase Chain Reaction; D013194:Staining and Labeling; D017154:Stromal Cells / Q000166:cytology / Q000637:transplantation / Q000648:ultrastructure; D013977:Tibia / Q000098:blood supply / Q000000981:diagnostic imaging / Q000187:drug effects / Q000502:physiology*; D054457:Tissue Scaffolds / Q000737:chemistry*; D055114:X-Ray Microtomography
D015675:Osteocalcin; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D000469:Alkaline Phosphatase