Macroporous scaffolds associated with cells to construct a hybrid biomaterial for bone tissue engineering
ABSTRACT Bone tissue has the ability to heal without a scar and to remodel, which promotes three basic functions: locomotion, protection of internal organs and mineral homeostasis. Although bone regeneration is highly efficient, some clinical situations - such as large bone defects - require specific treatments in order to promote bone healing. Allogenic or autologous bone grafts have been used in these procedures with limited success and, based on this, bone tissue-engineering approaches have been investigated extensively. Tissue engineering has been defined as the application of principles and techniques of the life sciences and engineering to the design, modification and growth of living tissues using biomaterials, cells and growth factors, alone or in combination. The association of cells with porous scaffolds to produce 3D hybrid osteogenic constructs is a common subject in bone tissue-engineering research and will be the focus of this review. We will present some aspects of bone biology, the cells and scaffolds used to engineer bone, and techniques to fabricate the hybrid biomaterial.
- SourceAvailable from: Emanuela Prado Ferraz[Show abstract] [Hide abstract]
ABSTRACT: OBJECTIVES: Autografts from mandibular symphysis and ramus are often used for bone reconstruction. Based on this, we hypothesized that these sites could be useful cell sources for bone tissue engineering approaches. Thus, our study aimed at evaluating the proliferation and osteoblast phenotype development of cells derived from mandibular symphysis and ramus. MATERIALS AND METHODS: Cells were isolated from bone fragments of four patients by enzymatic digestion and cultured under osteogenic condition for up to 17 days. Cultures were assayed for cell proliferation, gene expression of key bone markers runt-related transcription factor 2 (Runx2), distal-less homeobox 5 (DLX5), SATB homeobox 2 (SATB2), Osterix (OSX), family with sequence similarity 20, member C (FAM20C), bone sialoprotein (BSP), osteopontin (OPN) and osteocalcin (OC), alkaline phosphatase (ALP) expression and activity, and extracellular matrix mineralization. Data were compared by two-way ANOVA or t-test for independent samples when appropriate. RESULTS: Cells derived from ramus displayed lower proliferative activity and higher gene expression of Runx2, DLX5, SATB2, OSX, FAM20C, BSP, OPN and OC, ALP protein expression and activity and extracellular matrix mineralization compared with symphysis-derived cells. CONCLUSION: Symphysis and ramus may be considered as cell sources for bone tissue engineering approaches but due to the higher osteogenic potential, ramus-derived cells are more appealing for constructing cell-based biomaterials.Oral Diseases 04/2013; DOI:10.1111/odi.12115 · 2.40 Impact Factor
- [Show abstract] [Hide abstract]
ABSTRACT: There has been a consistent increase in the mean life expectancy of the population of the developed world over the past century. Healthy life expectancy, however, has not increased concurrently. As a result we are living a larger proportion of our lives in poor health and there is a growing demand for the replacement of diseased and damaged tissues. While traditionally tissue grafts have functioned well for this purpose, the demand for tissue grafts now exceeds the supply. For this reason, research in regenerative medicine is rapidly expanding to cope with this new demand. There is now a trend towards supplying cells with a material in order to expedite the tissue healing process. Hydrogel encapsulation provides cells with a three dimensional environment similar to that experienced in vivo and therefore may allow the maintenance of normal cellular function in order to produce tissues similar to those found in the body. In this review we discuss biopolymeric gels that have been used for the encapsulation of mammalian cells for tissue engineering applications as well as a brief overview of cell encapsulation for therapeutic protein production. This review focuses on agarose, alginate, collagen, fibrin, hyaluronic acid and gelatin since they are widely used for cell encapsulation. The literature on the regeneration of cartilage, bone, ligament, tendon, skin, blood vessels and neural tissues using these materials has been summarised.Biotechnology Letters 02/2010; 32(6):733-42. DOI:10.1007/s10529-010-0221-0 · 1.74 Impact Factor
- [Show abstract] [Hide abstract]
ABSTRACT: The properties of bone tissue engineering scaffolds such as architecture, porosity, mechanical properties and surface properties have significant effects on cellular response and play an important role in bone regeneration. In this study, threedimensional nanocomposite scaffolds consisting of calcium phosphate (Ca-P) nanoparticles and poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) copolymer with controlled external and internal architectures were successfully produced via selective laser sintering (SLS), one of the versatile rapid prototyping techniques. The Ca-P/PHBV nanocomposite scaffolds had a porosity of (61.75±1.24)%, compressive strength of (2.16±0.21) MPa and Young’s modulus of (26.98±2.29) MPa. The surface modification of scaffolds by gelatin was achieved through physical entrapment. The amount of entrapped gelatin could be controlled by varying the solvent composition and reaction time. The surface modification improved the hydrophilicity of scaffolds but did not significantly affect the surface morphology and mechanical properties. Osteoblast-like cells (SaOS-2) were cultured on scaffolds with and without gelatin surface modification. The majority of SaOS-2 cells were viable and proliferated in both types of scaffolds for up to 14 d in culture, as indicated by MTT assay and live and dead assay. Surface modification significantly increased cell proliferation for surface modified scaffolds, which could be due to the improvement in hydrophilicity of the scaffolds. Keywordsnanocomposite scaffold–selective laser sintering–surface modification–physical entrapment–cell behaviour01/2011; 5(1):57-68. DOI:10.1007/s11706-011-0101-0