TY - JOUR
T1 - Endochondral bone formation from hydrogel carriers loaded with BMP2-transduced cells
AU - Bikram, Malavosklish
AU - Fouletier-Dilling, Christine
AU - Hipp, John A.
AU - Gannon, Francis
AU - Davis, Alan R.
AU - Olmsted-Davis, Elizabeth A.
AU - West, Jennifer L.
N1 - Funding Information:
We thank James J. Moon, Melissa K. McHale, Jessica A. Shafer and Rachel E. Whitmire for technical assistance. This work was supported by Department of Defense award W81XWH-04-1-0068.
PY - 2007/5
Y1 - 2007/5
N2 - The success of ex vivo viral gene therapy systems for promoting bone formation could be improved through the development of systems to spatially localize gene expression. Towards this goal, we have encapsulated adenovirus-transduced human diploid fetal lung fibroblasts (MRC-5) expressing bone morphogenetic protein-type 2 (BMP-2) within non-degradable poly(ethylene glycol)-diacrylate (PEG-DA) hydrogels and implanted these intramuscularly to promote endochondral bone formation. To optimize BMP-2 secretion, the molecular weight of the polymers and cell densities were varied. Polymers with molecular weights of 6, 10, and 20 kDa were used to prepare hydrogels containing 1, 5, or 10 million transduced cells. The results showed that 10 million transduced fibroblasts that was the maximum number of cells feasible for encapsulation within PEG-DA 10 and 20 kDa hydrogels produced the highest amount of secreted BMP-2 protein. Encapsulation of MRC-5 and transduced fibroblasts resulted in 71 and 58% cell viability, respectively. The bioactivity of secreted BMP-2 protein from the hydrogels was confirmed with an alkaline phosphatase assay. Micro-CT of the lower limb muscles of NOD/SCID mice following implantation with hydrogels showed 39.5 ± 25.0 mm3 mineralized tissue and 31.8 ± 7.8 mm3 for the cell-injected mice, and the bone was localized to the hydrogel surfaces. Histology revealed bone as well as cartilage for both hydrogel implanted and cell-injected animals.
AB - The success of ex vivo viral gene therapy systems for promoting bone formation could be improved through the development of systems to spatially localize gene expression. Towards this goal, we have encapsulated adenovirus-transduced human diploid fetal lung fibroblasts (MRC-5) expressing bone morphogenetic protein-type 2 (BMP-2) within non-degradable poly(ethylene glycol)-diacrylate (PEG-DA) hydrogels and implanted these intramuscularly to promote endochondral bone formation. To optimize BMP-2 secretion, the molecular weight of the polymers and cell densities were varied. Polymers with molecular weights of 6, 10, and 20 kDa were used to prepare hydrogels containing 1, 5, or 10 million transduced cells. The results showed that 10 million transduced fibroblasts that was the maximum number of cells feasible for encapsulation within PEG-DA 10 and 20 kDa hydrogels produced the highest amount of secreted BMP-2 protein. Encapsulation of MRC-5 and transduced fibroblasts resulted in 71 and 58% cell viability, respectively. The bioactivity of secreted BMP-2 protein from the hydrogels was confirmed with an alkaline phosphatase assay. Micro-CT of the lower limb muscles of NOD/SCID mice following implantation with hydrogels showed 39.5 ± 25.0 mm3 mineralized tissue and 31.8 ± 7.8 mm3 for the cell-injected mice, and the bone was localized to the hydrogel surfaces. Histology revealed bone as well as cartilage for both hydrogel implanted and cell-injected animals.
KW - Adenovirus
KW - Biomaterials
KW - Bone
KW - Bone morphogenetic protein
KW - Cell encapsulation
KW - Gene therapy
KW - Hydrogel
KW - Tissue engineering
KW - Tissue repair
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U2 - 10.1007/s10439-007-9263-4
DO - 10.1007/s10439-007-9263-4
M3 - Article
C2 - 17340196
AN - SCOPUS:34247251993
SN - 0090-6964
VL - 35
SP - 796
EP - 807
JO - Annals of Biomedical Engineering
JF - Annals of Biomedical Engineering
IS - 5
ER -