High-Porosity Poly(ε-Caprolactone)/Mesoporous Silicon Scaffolds: Calcium Phosphate Deposition and Biological Response to Bone Precursor Cells

Abstract

In this study, the fabrication and characterization of highly porous composites composed of poly(epsilon-caprolactone) and bioactive mesoporous silicon (BioSilicon) prepared using salt-leaching and microemulsion/freeze-drying methods are described. The role of silicon, along with porosity, in the scaffolds on calcium phosphate deposition was assessed using acellular in vitro calcification analyses. The presence of bioactive silicon in these scaffolds is essential for the deposition of calcium phosphate while the samples are immersed in simulated body fluid (SBF). Silicon-containing scaffolds produced using salt-leaching methods are more likely to calcify as a consequence of SBF exposure than those produced using microemulsion methods. In vitro proliferation and cell viability assays of these porous composites using human embryonic kidney fibroblast cells indicate that no cytotoxic effects are present in the scaffolds under the conditions used. Preliminary analyses of bone sialoprotein and alkaline phosphatase expression using orthopedically relevant mesenchymal cells derived from bone marrow suggest that such scaffolds are capable of mediating osteoblast differentiation. Overall, the results show that these porous silicon-containing polymer scaffolds enhance calcification, can be considered nontoxic to cells, and support the proliferation, viability, attachment, and differentiation of bone precursor cells.

Biocompatibility assessment of Si-based nano- and micro-particles

“…Since then numerous reports in this field have been published. The focus of the majority of these studies was on in vitro interactions of pSi structures with biological substances, such as biodegradation in physiological conditions[65], calcification [66], cell adhesion [67], interaction with neuron interfaces and neural networks [68] and protein adsorption [69]. …”

The biocompatibility of porous silicon in tissues of the eye

“…Nanostructured porous silicon has been used as a scaffold for orthopaedic implants [7], and appropriately-derivatised porous silicon will support the attachment and growth of a variety of mammalian cells [8][9][10]. Stabilisation of the porous silicon surface in contact with physiological fluids is important in order to preserve the structural integrity of the material and to control the degradation kinetics during implantation.…”

Bioactive silicon nitride: A new therapeutic material for osteoarthropathy

“…Silicic acid (H 4 SiO 4 ), the dissolution product of bioactive glasses, was found to be effective in regulating the expression of osteoblastic markers and cell cycle genes14. Silicon-substituted hydroxyapatites, porous silicon, and silicon/silica nanoparticles were developed, all sharing the common mechanism of Si-enhanced bioactivity151617. As a complementary element, nitrogen from amino acids is essential for protein synthesis, bone growth, and tissue repair18.…”