Fusion performance of low-dose recombinant human bone morphogenetic protein 2 and bone marrow-derived multipotent stromal cells in biodegradable scaffolds: a comparative study in a large animal model of anterior lumbar interbody fusion.

Study Design: A large animal study comparing interbody fusion of a bioresorbable scaffold loaded with either low-dose recombinant human bone morphogenetic protein 2 (rhBMP-2) or bone marrow-derived multipotent stromal cells (BMSCs).

Objective: To compare the quality of fusion resulting from implantation of medical grade poly (ε-caprolactone)-20% tricalcium phosphate (mPCL/TCP) scaffolds and two different bone growth stimulating agents.

Summary Of Background Data: Nondegradable cages have been used for interbody fusion with good results.

Hyaluronan-based heparin-incorporated hydrogels for generation of axially vascularized bioartificial bone tissues: in vitro and in vivo evaluation in a PLDLLA-TCP-PCL-composite system.

Smart matrices are required in bone tissue-engineered grafts that provide an optimal environment for cells and retain osteo-inductive factors for sustained biological activity. We hypothesized that a slow-degrading heparin-incorporated hyaluronan (HA) hydrogel can preserve BMP-2; while an arterio-venous (A-V) loop can support axial vascularization to provide nutrition for a bio-artificial bone graft. HA was evaluated for osteoblast growth and BMP-2 release.

Autogenous bone marrow stromal cell sheets-loaded mPCL/TCP scaffolds induced osteogenesis in a porcine model of spinal interbody fusion.

This study was designed to investigate whether a tissue-engineered construct composed of autogenous cell sheets and a polycaprolactone-based bioresorbable scaffold would enhance bone regeneration and spinal interbody fusion in a large animal model. Porcine-derived autogenous bone marrow stromal cells (BMSCs) cultured into multilayered cell sheets were induced into osteogenic differentiation with dexamethasone, l-ascorbic acid, and β-glycerol phosphate. These cell sheets were assembled with bioresorbable scaffolds made from medical-grade poly(epsilon-caprolactone) incorporating 20% β-tricalcium phosphate (mPCL/TCP) as tissue-engineered BMSC constructs.

Biomimetic composite coating on rapid prototyped scaffolds for bone tissue engineering.

The objective of this present study was to improve the functional performance of rapid prototyped scaffolds for bone tissue engineering through biomimetic composite coating. Rapid prototyped poly(ε-caprolactone)/tri-calcium phosphate (PCL/TCP) scaffolds were fabricated using the screw extrusion system (SES). The fabricated PCL/TCP scaffolds were coated with a carbonated hydroxyapatite (CHA)-gelatin composite via biomimetic co-precipitation.

Dynamics of in vitro polymer degradation of polycaprolactone-based scaffolds: accelerated versus simulated physiological conditions.

The increasing use of biodegradable devices in tissue engineering and regenerative medicine means it is essential to study and understand their degradation behaviour. Accelerated degradation systems aim to achieve similar degradation profiles within a shorter period of time, compared with standard conditions. However, these conditions only partially mimic the actual situation, and subsequent analyses and derived mechanisms must be treated with caution and should always be supported by actual long-term degradation data obtained under physiological conditions.

Evaluation of polycaprolactone scaffold degradation for 6 months in vitro and in vivo.

The use of polycaprolactone (PCL) as a biomaterial, especially in the fields of drug delivery and tissue engineering, has enjoyed significant growth. Understanding how such a device or scaffold eventually degrades in vivo is paramount as the defect site regenerates and remodels. Degradation studies of three-dimensional PCL and PCL-based composite scaffolds were conducted in vitro (in phosphate buffered saline) and in vivo (rabbit model).

Biomaterials/scaffolds. Design of bioactive, multiphasic PCL/collagen type I and type II-PCL-TCP/collagen composite scaffolds for functional tissue engineering of osteochondral repair tissue by using electrospinning and FDM techniques.

Current clinical therapies for traumatic or chronic injuries involving osteochondral tissue result in temporary pain reduction and filling of the defect but with biomechanically inferior repair tissue. Tissue engineering of osteochondral repair tissue using autologous cells and bioactive biomaterials has the potential to overcome the current limitations and results in native-like repair tissue with good integration capabilities. For this reason, we applied two modem biomaterial design techniques, namely, electrospinning and fused deposition modeling (FDM), to produce bioactive poly(epsilon-caprolactone)/collagen (PCL/Col) type I and type II-PCL-tri-calcium phosphate (TCP)/Col composites for precursor cell-based osteochondral repair.

State of the art and future directions of scaffold-based bone engineering from a biomaterials perspective.

Scaffold-based bone tissue engineering aims to repair/regenerate bone defects. Such a treatment concept involves seeding autologous osteogenic cells throughout a biodegradable scaffold to create a scaffold-cell hybrid that may be called a tissue-engineered construct (TEC). A variety of materials and scaffolding fabrication techniques for bone tissue engineering have been investigated over the past two decades.

Repair of calvarial defects with customised tissue-engineered bone grafts II. Evaluation of cellular efficiency and efficacy in vivo.

We have demonstrated in Part I of this study [see Schantz, J.-T., et al.

Repair of calvarial defects with customized tissue-engineered bone grafts I. Evaluation of osteogenesis in a three-dimensional culture system.

Bone generation by autogenous cell transplantation in combination with a biodegradable scaffold is one of the most promising techniques being developed in craniofacial surgery. The objective of this combined in vitro and in vivo study was to evaluate the morphology and osteogenic differentiation of bone marrow derived mesenchymal progenitor cells and calvarial osteoblasts in a two-dimensional (2-D) and three-dimensional (3-D) culture environment (Part I of this study) and their potential in combination with a biodegradable scaffold to reconstruct critical-size calvarial defects in an autologous animal model [Part II of this study; see Schantz, J.T.