Healing of massive segmental femoral bone defects in minipigs by allogenic ASCs engineered with FLPo/Frt-based baculovirus vectors. (May 2015)

• Record Type: Journal Article
• Authors: Lin, Chin-Yu; Wang, Yao-Horng; Li, Kuei-Chang; Sung, Li-Yu; Yeh, Chia-Lin; Lin, Kun-Ju; Yen, Tzu-Chen; Chang, Yu-Han; Hu, Yu-Chen
• Is Part Of: Biomaterials. Volume 50(2015)
• Page Start: 98
• Page End: 106
• Publication Date: 2015-05
• Subjects: Adipose-derived stem cells -- Baculovirus -- Minipig -- Pre-clinical -- Massive bone defects -- Gene therapy; Biomedical materials -- Periodicals; Biocompatible Materials -- Periodicals; Biomatériaux -- Périodiques; 610.28
• DOI: 10.1016/j.biomaterials.2015.01.052
• Languages: English
• ISSNs: 0142-9612

Abstract

Abstract: Adipose-derived stem cells (ASCs) hold promise for bone regeneration but possess inferior osteogenesis potential. Allotransplantation of ASCs engineered with the BMP2/VEGF-expressing baculoviruses into rabbits healed critical-size segmental bone defects. To translate the technology to clinical applications, we aimed to demonstrate massive bone healing in minipigs that more closely mimicked the clinical scenarios, using a new hybrid baculovirus system consisting of BacFLPo expressing the codon-optimized FLP recombinase (FLPo) and the substrate baculovirus harboring the transgene flanked by Frt sequences. Co-transduction of minipig ASCs (pASCs) with BacFLPo and the substrate baculovirus enabled transgene cassette excision, recombination and minicircle formation in ≈73.7% of pASCs, which substantially prolonged the transgene (BMP2 and VEGF) expression to 28 days. When encoding BMP2, the FLPo/Frt-based system augmented the pASCs osteogenesis. Allotransplantation of the BMP2/VEGF-expressing pASCs into minipigs healed massive segmental bone defects (30 mm in length) at the mid-diaphysis of femora, as evaluated by computed tomography, positron emission tomography, histology, immunohistochemical staining and biochemical testing. The defect size was ≈15% of femoral length in minipigs and was equivalent to ≈60–70 mm of femoral defect in humans, thus the healing using pASCs engineered with the FLPo/Frt-based baculovirus represented a remarkable advance for the treatment of massive bone defects.