Three‐dimensional nanocomposite scaffolds with ordered cylindrical orthogonal pores

Abstract

A silica reinforcement can improve the mechanical properties of hydrogels in the rubbery state. A method to prepare a scaffold with a well-ordered array of cylindrical pores is presented in this work, which yields a scaffold with a biphasic matrix of a hybrid nanocomposite: the hydrogel poly(2-hydroxyethyl acrylate) (PHEA) and a silica network obtained by an acid catalyzed sol-gel process of tetraethoxysilane (TEOS). As porogenic template of the scaffold stacked layers of commercial polyamide 6 fabrics were used, which were compressed and sintered. Porosity and dynamic mechanical response of the resulting scaffolds were measured and compared with the bulk properties. Removal of the organic polymer phase of the scaffold by pyrolysis revealed the overall continuity of the silica network; the residue maintained the original cylindrical pore structure of the scaffolds, though slightly shrunk. Atomic force microscopy topography measurements of these pyrolysed residues revealed a silica structure with particle aggregates having sizes around tens of nanometers. The silica distribution was assessed by X-ray microanalysis mapping, showing homogeneity at a micrometer scale.

Microcomputed tomography and microfinite element modeling for evaluating polymer scaffolds architecture and their mechanical properties

“…The pore size distribution of the second structure [interconnected channels, Figure 2(d)] is less symmetric (with a long tail toward the high pore sizes), with maximum around 100 μm and mean around 150 μm, in excellent agreement with the nominal tread diameter of the commercial textile fabric employed as a porogen 36…”

“…The relationship between the architecture of three different polymer scaffolds and their mechanical properties are shown in this work. On the one hand, the network of interconnected spherical pores [Figure 1(a)], the structure based on interconnected pores obtained from salt particles (not shown), and the one which consists of interconnected longitudinal channels along three orthogonal axes [Figure 1(b)] 36. Besides, the materials chemistry and hydrophilicity of the material forming the first structure has been modified in a broad range.…”

“…A detailed procedure regarding obtaining this particular pore architecture is explained elsewhere 36. Briefly, a fixed number of polyamide 6.6 sheets of commercial textile fabrics (SAATI S.A., Barcelona, Spain) were used to build well‐ordered structures to serve as porogenic templates.…”

Latest Improvements of Acrylic-Based Polymer Properties for Biomedical Applications

“…Thus, a biphasic matrix of a hybrid (inorganic-organic) nanocomposite materials of poly(2-hydroxyethyl acrylate) with a silica network obtained by an acid-catalyzed sol-gel process of tetraethoxysilane (TEOS) showed a very significant improvement of the mechanical properties of the pure hydrogel [37].…”

“…Therefore, it is Latest Improvements of Acrylic-Based Polymer Properties for Biomedical Applications http://dx.doi.org/10.5772/intechopen.68996 87 usually necessary to enhance the mechanical properties of these porous structures by means of the methods, shown in Chapter 2, with nanomaterials or other techniques. For example, the use of a hybrid hydrogel nanocomposite of silica/poly(2-hydroxyethyl acrylate) as scaffold material matrix greatly improves the mechanical properties, and the silica phase of the scaffold was effectively interconnected and continuous, able to withstand pyrolysis without losing the pore architecture of the scaffold [37].…”