41 research outputs found
Formation of bone-like apatite layer on chitosan fiber mesh scaffolds by a biomimetic spraying process
Bone-like apatite coating of polymeric substrates
by means of biomimetic process is a possible
way to enhance the bone bonding ability of the
materials. The created apatite layer is believed to have
an ability to provide a favorable environment for
osteoblasts or osteoprogenitor cells. The purpose of
this study is to obtain bone-like apatite layer onto
chitosan fiber mesh tissue engineering scaffolds, by
means of using a simple biomimetic coating process
and to determine the influence of this coating on
osteoblastic cell responses. Chitosan fiber mesh scaffolds
produced by a previously described wet spinning
methodology were initially wet with a Bioglass"–water
suspension by means of a spraying methodology and
then immersed in a simulated body fluid (SBF)
mimicking physiological conditions for one week. The
formation of apatite layer was observed morphologically
by scanning electron microscopy (SEM). As a
result of the use of the novel spraying methodology, a
fine coating could also be observed penetrating into the
pores, that is clearly within the bulk of the scaffolds.
Fourier Transform Infrared spectroscopy (FTIRATR),
Electron Dispersive Spectroscopy (EDS) and
X-ray diffraction (XRD) analysis also confirmed the
presence of apatite-like layer. A human osteoblast-like
cell line (SaOs-2) was used for the direct cell contact assays. After 2 weeks of culture, samples were observed
under the SEM. When compared to the control
samples (unmodified chitosan fiber mesh scaffolds) the
cell population was found to be higher in the Ca–P
biomimetic coated scaffolds, which indicates that the
levels of cell proliferation on this kind of scaffolds
could be enhanced. Furthermore, it was also observed
that the cells seeded in the Ca–P coated scaffolds have
a more spread and flat morphology, which reveals an
improvement on the cell adhesion patterns, phenomena
that are always important in processes such as
osteoconduction
Gene-enhanced tissue engineering for dental hard tissue regeneration: (1) overview and practical considerations
Gene-based therapies for tissue regeneration involve delivering a specific gene to a target tissue with the goal of changing the phenotype or protein expression profile of the recipient cell; the ultimate goal being to form specific tissues required for regeneration. One of the principal advantages of this approach is that it provides for a sustained delivery of physiologic levels of the growth factor of interest. This manuscript will review the principals of gene-enhanced tissue engineering and the techniques of introducing DNA into cells. Part 2 will review recent advances in gene-based therapies for dental hard tissue regeneration, specifically as it pertains to dentin regeneration/pulp capping and periodontal regeneration
Structural Characterization and Biological Fluid Interaction of Sol−Gel-Derived Mg-Substituted Biphasic Calcium Phosphate Ceramics
In Vivo Ectopic Implantation Model to Assess Human Mesenchymal Progenitor Cell Potential
Clinical interest on human mesenchymal progenitor cells (hMPC) relies on their potential applicability in cell-based therapies. An in vitro characterization is usually performed in order to define MPC potency. However, in vitro predictions not always correlate with in vivo results and thus there is no consensus in how to really assess cell potency. Our goal was to provide an in vivo testing method to define cell behavior before therapeutic usage, especially for bone tissue engineering applications. In this context, we wondered whether bone marrow stromal cells (hBMSC) would proceed in an osteogenic microenvironment. Based on previous approaches, we developed a fibrin/ceramic/BMP-2/hBMSCs compound. We implanted the compound during only 2Â weeks in NOD-SCID mice, either orthotopically to assess its osteoinductive property or subcutaneously to analyze its adequacy as a cell potency testing method. Using fluorescent cell labeling and immunohistochemistry techniques, we could ascertain cell differentiation to bone, bone marrow, cartilage, adipocyte and fibrous tissue. We observed differences in cell potential among different batches of hBMSCs, which did not strictly correlate with in vitro analyses. Our data indicate that the method we have developed is reliable, rapid and reproducible to define cell potency, and may be useful for testing cells destined to bone tissue engineering purposes. Additionally, results obtained with hMPCs from other sources indicate that our method is suitable for testing any potentially implantable mesenchymal cell. Finally, we propose that this model could successfully be employed for bone marrow niche and bone tumor studies. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s12015-013-9464-1) contains supplementary material, which is available to authorized users