ABSTRACT
The aim of this study was to evaluate the osteogenic potential and the vascularization of embroidered, tissue engineered, and cell-seeded 3D poly(3)hydroxybutyrate (PHB) scaffolds in nude rats. Collagen I (coll I)- and collagen I/chondroitin sulfate (coll I/CS)-coated PHB scaffolds were seeded with human mesenchymal stem cells (hMSCs). Proliferation and differentiation were characterized by different biochemical assays in vitro. For animal experiments, the cells were cultivated on coll I- or coll I/CS-coated scaffolds and either expanded or osteogenically differentiated. Scaffolds were piled up to create a 3D scaffold pad and implanted subcutaneously into nude rats. In vitro hMSC showed proliferation and differentiation on PHB scaffolds. Alkaline phosphatase (ALP) and calcium increased in the differentiation medium and in the presence of coll I/CS. In vivo blood vessels were found in the scaffold-stack. Histological/immunohistological analyses of explanted scaffolds showed osteogenic markers such as osteopontin, osteonectin, and coll I around the PHB fibers. Coll I/CS-coated scaffolds with expanded hMSC showed higher values of ALP and calcium than the other combinations. Embroidered PHB scaffolds, coated with extracellular matrix components, provided an adequate environment and, therefore, a template for hMSC which could be differentiated in osteogenic direction.
Subject(s)
Hydroxybutyrates/pharmacology , Materials Testing , Neovascularization, Physiologic/drug effects , Osteogenesis/drug effects , Polyesters/pharmacology , Prosthesis Implantation , Subcutaneous Tissue/drug effects , Tissue Scaffolds/chemistry , Alkaline Phosphatase/metabolism , Animals , Calcium/metabolism , Cell Adhesion/drug effects , Cell Differentiation/drug effects , Cell Proliferation/drug effects , Collagen Type II/pharmacology , Humans , Immunohistochemistry , Mesenchymal Stem Cells/cytology , Mesenchymal Stem Cells/drug effects , Mesenchymal Stem Cells/enzymology , Mesenchymal Stem Cells/ultrastructure , Prohibitins , Rats , Rats, Nude , Subcutaneous Tissue/diagnostic imaging , Surface Properties/drug effects , Tomography, X-Ray ComputedABSTRACT
The aim of this study was to evaluate an embroidered polycaprolactone-co-lactide (trade name PCL) scaffold for the application in bone tissue engineering. The surface of the PCL scaffolds was hydrolyzed with NaOH and coated with collagen I (coll I) and chondroitin sulfate (CS). It was investigated if a change of the surface properties and the application of coll I and CS could promote cell adhesion, proliferation, and osteogenic differentiation of human mesenchymal stem cells (hMSC). The porosity (80%) and pore size (0.2-1 mm) of the scaffold could be controlled by embroidery technique and should be suitable for bone ingrowth. The treatment with NaOH made the polymer surface more hydrophilic (water contact angle dropped to 25%), enhanced the coll I adsorption (up to 15%) and the cell attachment (two times). The coll I coated scaffold improved cell attachment and proliferation (three times). CS, as part of the artificial matrix, could induce the osteogenic differentiation of hMSC without other differentiation additives. The investigated scaffolds could act not just as temporary matrix for cell migration, proliferation, and differentiation in bone tissue engineering but also have a great potential as bioartificial bone substitute.
