Bioactive scaffolds mimicking natural dentin structure

Abstract

Organic scaffolds of poly(ethyl methacrylate-co-hydroxyethyl acrylate) [P(EMA-co-HEA)] 70/30 wt % ratio, with varying proportions of silica SiO(2) from 0 to 20 wt % and aligned tubular pores, were prepared using a fiber-templating fabrication method, with the aim of mimicking structure and properties of the mineralized tissue of natural dentin. Precursors of the copolymer and silica were simultaneously polymerized in a sol-gel process within the fiber template, which was eventually eliminated to generate homogeneously distributed parallel micrometer-sized pores in the material. Scaffolds of PEMA and PHEA were obtained by the same approach. The scaffolds were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy, and thermogravimetric analysis. The specific volume was determined by Archimedes' method and the porosity calculated from the geometry. The mechanical properties were analyzed in tensile and compressive modes. The bioactivity of the scaffolds with 15 wt % SiO(2) was tested by immersion in simulated body fluid (SBF) for 7 days followed by immersion in 2x SBF for 7 days. These scaffolds were afterwards characterized by SEM, energy dispersive spectroscopy, and compression assays. Percentages of silica above 10 wt % reinforced mechanically the copolymer, evidenced by the hindrance of the long range motions of the organic chains, altered shrinkage and swelling, and meanwhile conferred bioactivity to its surface. These tubular porous structures, which resemble natural dentin with regard to its structure and properties and induce the precipitation of apatite on their surfaces in vitro, are expected to facilitate the integration in the host mineralized tissue, to stimulate cell growth and to be useful as guiding scaffolds for in vivo dentin regeneration.

Dental stem cells: The role of biomaterials and scaffolds in developing novel therapeutic strategies

“…Scaffolds developed from either synthetic or natural biomaterials have been used for tooth reconstruction. Natural materials, such as collagen[ 91 ], chitosan/gelatin[ 92 ], silk protein[ 93 ], alginate[ 94 ], hyaluronic acid[ 95 ] as well as synthetic polymers, such as polyglycolate/poly-l-lactate[ 96 ], polycaprolactone-poly glycolic acid[ 97 ], polylactic acid-co-polyglycolic acid[ 98 ], polycaprolactone /gelatin/ nano- hydroxyapatite[ 99 ], nano-hydroxyapatite/collagen/poly-l-lactide[ 100 ] and poly-ethyl methacrylate-co-hydroxyethyl acrylate[ 101 ] were used as scaffold materials for dental restoration and regeneration. Several investigations have indicated the regeneration of vascularized pulp-like tissue after subcutaneous implantation of tooth slices containing DSCs accompanied by an appropriate scaffold, particularly in the presence of growth factors such as dentin matrix protein[ 102 , 103 ].…”

Fibrin coating on poly (L-lactide) scaffolds for tissue engineering

“…Las características de la estructura molecular del PEA, movilidad de la cadena lateral, la polaridad y su baja hidrofilicidad, permiten que tenga lugar una interacción directa entre el polímero y las proteínas de la matriz extracelular. Por otra parte, es posible llevar a cabo la preparación de materiales ultraporosos, que permiten la invasión celular y que se utilizan como guías para el crecimiento celular, son los "scaffolds" (21)(22)(27)(28)(29)(30)(31)(32)(33)(34)(35)(36) . Además mediante distintas variantes de la técnica de porógeno-lixiviación se consiguen distintas estructuras porosas (27-29, 31, 33-36) .…”

Accelerated hardening of nanotextured 3D-plotted self-setting calcium phosphate inks

“…The effects of sintering conditions on the chemical, structural and mechanical properties of those samples have been deeply studied. [11,16,25,26] Recently, the possibility to fabricate low-temperature self-setting inks that do not require the sintering step has been proposed, using formulations based on beta-calcium silicate (-CaSiO 3 ), [20,27] magnesium phosphates [28] or calcium phosphates. [29,30] Most calcium phosphate self-setting inks are based on alpha-tricalcium phosphate (-TCP), which can be combined with different binders, like gelatine, [29] type I collagen [31] hydroxypropyl methylcellulose (HPMC), [32] Polysorbate 80 (Tween 80) and short-chain triglycerides (Miglyol 812), [30,33,34] polyvinyl alcohol [33] and alginic acid.…”