Evaluation of different scaffolds for BMP‐2 genetic orthopedic tissue engineering

Abstract

To better understand the effects of scaffold materials for bone morphogenetic protein 2 (BMP-2) genetic tissue engineering in vivo, several gels, including alginate, collagen, agarose, hyaluronate, fibrin, or Pluronic, were mixed with adenovirus-mediated human BMP-2 gene (Adv-hBMP-2) transduced bone marrow stromal cells (BMSCs) and injected into the muscles of athymic mice to evaluate the resulting osteogenesis and chondrogenesis. These gel and gene-transduced BMSC mixtures were also loaded onto beta-TCP/HAP biphasic calcined bone (BCB) and observed under scanning electron microscopy (SEM). In addition, these composite scaffolds were implanted into the subcutaneous site of athymic mice to construct tissue-engineered bone. After injection, collagen, hyaluronate, or alginate gel mixed with gene-transduced BMSCs induced more bone formation than a cell suspension in alpha-MEM. The agarose-gene-transduced BMSC gel was found to contain much more hyaline cartilage. SEM showed the BMSCs could survive in alginate, agarose, and collagen gel in vitro for up to 8 d. After implantation of tissue-engineered bone, the alginate, collagen, and agarose gel could promote new bone formation within a BCB in vivo. Little or no bone formed after injection of fibrin or Pluronic gel mixed with BMSCs or implantation with BCB. These findings help to elucidate the effects of various scaffold materials for future research in orthopedic tissue engineering using BMP-2 transduced cells.

Enhancement of recombinant human BMP‐7 bone formation with bmp binding peptide in a rodent femoral defect model

“…12 Therefore, an effective carrier must be used to achieve a localized effect at the desired bone healing site. BMP carriers can be classified as naturally occurring polymers, 13,14 synthetic polymers, 15 composites of synthetic and naturally occurring polymers, 8 and inorganic salts. 16 Bovine bonederived type I collagen is used as a carrier to bind rhBMP-7 in the clinical setting.…”

Baculovirus as a new gene delivery vector for stem cell engineering and bone tissue engineering

“…50 The hMSCs were transduced at MOI 40 and cultured as described above. At 6 days post-transduction, the cells were supertransduced at MOI 40, trypsinized the following day, centrifuged and resuspended in PBS (1 Â 10 7 cells/ml).…”

Engineering New Bone via a Minimally Invasive Route Using Human Bone Marrow-Derived Stromal Cell Aggregates, Microceramic Particles, and Human Platelet-Rich Plasma Gel

“…Several injectable gels and cements such as calcium phosphate cements (CPC), polymeric gels, agarose, hyaluronate, cellulose, fibrinogen based gels, collagen and pluronic acid have been suggested as an injectable biomaterials for the purpose of bone tissue engineering [11][12][13]. While the CPCs provide good biomechanical stability, the exothermic reactions associated with their setting process prove to be a deterrent in combining them with cells.…”

“…The degradation products of pluronic acid are cytotoxic whilst the curing of hyaluronic acid from solution to a gel is difficult making it unsuitable for routine clinical use. Gels from synthetic polymers often result in inflammatory reactions [12]. Collagen, alginate and fibrinogen based gels are biocompatible and thus suitable for use with cells.…”