J. Funct. Biomater.2016, 7(3), 16; doi:10.3390/jfb7030016 - published 28 June 2016 Show/Hide Abstract
Abstract: This article is an updated review of the published literature on glass-ionomer cements and covers their structure, properties and clinical uses within dentistry, with an emphasis on findings from the last five years or so. Glass-ionomers are shown to set by an acid-base reaction within 2–3 min and to form hard, reasonably strong materials with acceptable appearance. They release fluoride and are bioactive, so that they gradually develop a strong, durable interfacial ion-exchange layer at the interface with the tooth, which is responsible for their adhesion. Modified forms of glass-ionomers, namely resin-modified glass-ionomers and glass carbomer, are also described and their properties and applications covered. Physical properties of the resin-modified glass-ionomers are shown to be good, and comparable with those of conventional glass-ionomers, but biocompatibility is somewhat compromised by the presence of the resin component, 2 hydroxyethyl methacrylate. Properties of glass carbomer appear to be slightly inferior to those of the best modern conventional glass-ionomers, and there is not yet sufficient information to determine how their bioactivity compares, although they have been formulated to enhance this particular feature.
J. Funct. Biomater.2016, 7(2), 15; doi:10.3390/jfb7020015 - published 14 June 2016 Show/Hide Abstract
Abstract: Disorders affecting the temporomandibular joint (TMJ) are a long-standing health concern. TMJ disorders (TMJD) are often associated with an internal disc derangement accompanied by a suite of symptoms including joint noises, jaw dysfunction, and severe pain. The severity of patient symptoms and their reoccurrence can be alleviated to some extent with conservative therapy; however, refractory cases often require surgery that has shown only limited success. Bioengineered scaffolds with cell supportive surfaces an d nanoarchitectures that mimic TMJ tissue structure may offer an alternative treatment modality. In this study, titanium dioxide (TiO2) nanothin films, fabricated by layer-by-layer assembly, were examined as means for creating such a scaffold. The viability and growth of TMJ discal fibrochondrocytes (FCs) were assessed through MTT and DNA assays and total protein content over a 14-day experimental period. ELISA was also used to measure expression of types I and II collagen, decorin and aggrecan. Quantitative analyses demonstrated that FCs synthesized characteristic discal matrix proteins, with an increased production of type I collagen and decorin as opposed to collagen type II and aggrecan. A stimulatory effect on discal FC proliferation and extracellular matrix (ECM) expression with thicker nanofilms was also observed. The cumulative results suggest that TiO2 nanofilms may have potential as a TMJ scaffolding material.
J. Funct. Biomater.2016, 7(2), 14; doi:10.3390/jfb7020014 - published 3 June 2016 Show/Hide Abstract
Abstract: A layered construct was developed by combining a porous polymer sheet and a cell sheet as a tissue engineered vascular patch. The primary objective of this study is to investigate the influence of mesenchymal stem cells (MSCs) sheet on the tensile mechanical properties of porous poly-(l-lactide-co-ε-caprolactone) (PLCL) sheet. The porous PLCL sheet was fabricated by the solid-liquid phase separation method and the following freeze-drying method. The MSCs sheet, prepared by the temperature-responsive dish, was then layered on the top of the PLCL sheet and cultured for 2 weeks. During the in vitro study, cellular properties such as cell infiltration, spreading and proliferation were evaluated. Tensile test of the layered construct was performed periodically to characterize the tensile mechanical behavior. The tensile properties were then correlated with the cellular properties to understand the effect of MSCs sheet on the variation of the mechanical behavior during the in vitro study. It was found that MSCs from the cell sheet were able to migrate into the PLCL sheet and actively proliferated into the porous structure then formed a new layer of MSCs on the opposite surface of the PLCL sheet. Mechanical evaluation revealed that the PLCL sheet with MSCs showed enhancement of tensile strength and strain energy density at the first week of culture which is characterized as the effect of MSCs proliferation and its infiltration into the porous structure of the PLCL sheet. New technique was presented to develop tissue engineered patch by combining MSCs sheet and porous PLCL sheet, and it is expected that the layered patch may prolong biomechanical stability when implanted in vivo.
J. Funct. Biomater.2016, 7(2), 13; doi:10.3390/jfb7020013 - published 19 May 2016 Show/Hide Abstract
Abstract: Since its discovery in the years of the French Revolution, the field of keratoprostheses has evolved significantly. However, the path towards its present state has not always been an easy one. Initially discarded for its devastating complications, the introduction of new materials and the discovery of antibiotics in the last century gave new life to the field. Since then, the use of keratoprostheses for severe ocular surface disorders and corneal opacities has increased significantly, to the point that it has become a standard procedure for corneal specialists worldwide. Although the rate of complications has significantly been reduced, these can impede the long-term success, since some of them can be visually devastating. In an attempt to overcome these complications, researchers in the field have been recently working on improving the design of the currently available devices, by introducing the use of new materials that are more biocompatible with the eye. Here we present an update on the most recent research in the field.
J. Funct. Biomater.2016, 7(2), 11; doi:10.3390/jfb7020011 - published 20 April 2016 Show/Hide Abstract
Abstract: Blood vessel reconstruction is still an elusive goal for the development of in vitro models as well as artificial vascular grafts. In this study, we used a novel photo-curable cytocompatible polyacrylate material (PA) for freeform generation of synthetic vessels. We applied stereolithography for the fabrication of arbitrary 3D tubular structures with total dimensions in the centimeter range, 300 µm wall thickness, inner diameters of 1 to 2 mm and defined pores with a constant diameter of approximately 100 µm or 200 µm. We established a rinsing protocol to remove remaining cytotoxic substances from the photo-cured PA and applied thio-modified heparin and RGDC-peptides to functionalize the PA surface for enhanced endothelial cell adhesion. A rotating seeding procedure was introduced to ensure homogenous endothelial monolayer formation at the inner luminal tube wall. We showed that endothelial cells stayed viable and adherent and aligned along the medium flow under fluid-flow conditions comparable to native capillaries. The combined technology approach comprising of freeform additive manufacturing (AM), biomimetic design, cytocompatible materials which are applicable to AM, and biofunctionalization of AM constructs has been introduced as BioRap® technology by the authors.