Adhesion and Proliferation of Human Mesenchymal Stem Cells from Dental Pulp on Porous Silicon Scaffolds

Abstract

In regenerative medicine, stem-cell-based therapy often requires a scaffold to deliver cells and/or growth factors to the injured site. Porous silicon (pSi) is a promising biomaterial for tissue engineering as it is both nontoxic and bioresorbable. Moreover, surface modification can offer control over the degradation rate of pSi and can also promote cell adhesion. Dental pulp stem cells (DPSC) are pluripotent mesenchymal stem cells found within the teeth and constitute a readily source of stem cells. Thus, coupling the good proliferation and differentiation capacities of DPSC with the textural and chemical properties of the pSi substrates provides an interesting approach for therapeutic use. In this study, the behavior of human DPSC is analyzed on pSi substrates presenting pores of various sizes, 10 ± 2 nm, 36 ± 4 nm, and 1.0 ± 0.1 μm, and undergoing different chemical treatments, thermal oxidation, silanization with aminopropyltriethoxysilane (APTES), and hydrosilylation with undecenoic acid or semicarbazide. DPSC adhesion and proliferation were followed for up to 72 h by fluorescence microscopy, scanning electron microscopy (SEM), enzymatic activity assay, and BrdU assay for mitotic activity. Porous silicon with 36 nm pore size was found to offer the best adhesion and the fastest growth rate for DPSC compared to pSi comporting smaller pore size (10 nm) or larger pore size (1 μm), especially after silanization with APTES. Hydrosilylation with semicarbazide favored cell adhesion and proliferation, especially mitosis after cell adhesion, but such chemical modification has been found to led to a scaffold that is stable for only 24-48 h in culture medium. Thus, semicarbazide-treated pSi appeared to be an appropriate scaffold for stem cell adhesion and immediate in vivo transplantation, whereas APTES-treated pSi was found to be more suitable for long-term in vitro culture, for stem cell proliferation and differentiation.

Effect of Different Endodontic Regeneration Protocols on Wettability, Roughness, and Chemical Composition of Surface Dentin

“…The topography and 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 3 chemical structure of dentin surface are surface properties that may play an important role in modifying dentin wettability during endodontic regeneration. These surface properties were also suggested to have significant effect on the attachment and proliferation of dental pulp stem cells (12)(13)(14)(15). This study aimed to investigate the changes in wettability, roughness, and chemical structure of surface dentin after various endodontic regeneration protocols.…”

Initial stem cell adhesion on porous silicon surface: molecular architecture of actin cytoskeleton and filopodial growth

“…An essential challenge in tissue engineering is the understanding of cell-substrate interactions, which are involved in the difference observed in cell behavior when comparing in vitro and in vivo culturing [3,4]. Indeed, stem cell-based therapies often require a scaffold to carry stem cells to the injured site [5]. In human body, cells are in contact with each other and with ECM, all of them exhibiting nanostructures such as nanopores, nanofibers, or arrangements of adhesion proteins.…”

“…Thus, a biomaterial scaffold for tissue engineering should ideally mimic the chemical and mechanical properties of in vivo environment, in order to support cell attachment, proliferation, and differentiation. In this field, porous silicon (pSi) appears to be a promising biomaterial as it is both nontoxic and bioresorbable under physiological conditions and dissolves progressively into nontoxic silicic acid [5,9,10]. PSi is a semiconductor material obtained by electrochemical etching of flat silicon.…”

Dental Pulp Stem Cell Niche

“…The hydroxyapatite-polycaprolactone (HA-PCL) composite scaffolds can also promote the proliferation of both human BMMSCs and DPSCs [58]. Porous silicon scaffolds with 36 nm pore size can offer the best adhesion and fastest growth rate for DPSCs [59]. DPSCs also showed some proliferation and mineralization characteristics on electrospun poly (epsilon-caprolactone) (PCL)/gelatin scaffolds with or without the addition of nano-hydroxyapatite [60].…”