Fluorapatite-modified Scaffold on Dental Pulp Stem Cell Mineralization

Abstract

In previous studies, fluorapatite (FA) crystal-coated surfaces have been shown to stimulate the differentiation and mineralization of human dental pulp stem cells (DPSCs) in two-dimensional cell culture. However, whether the FA surface can recapitulate these properties in three-dimensional culture is still unknown. This study examined the differences in behavior of human DPSCs cultured on electrospun polycaprolactone (PCL) NanoECM nanofibers with or without the FA crystals. Under near-physiologic conditions, the FA crystals were synthesized on the PCL nanofiber scaffolds. The FA crystals were evenly distributed on the scaffolds. DPSCs were cultured on the PCL+FA or the PCL scaffolds for up to 28 days. Scanning electron microscope images showed that DPSCs attached well to both scaffolds after the initial seeding. However, it appeared that more multicellular aggregates formed on the PCL+FA scaffolds. After 14 days, the cell proliferation on the PCL+FA was slower than that on the PCL-only scaffolds. Interestingly, even without any induction of mineralization, from day 7, the upregulation of several pro-osteogenic molecules (dmp1, dspp, runx2, ocn, spp1, col1a1) was detected in cells seeded on the PCL+FA scaffolds. A significant increase in alkaline phosphatase activity was also seen on FA-coated scaffolds compared with the PCL-only scaffolds at days 14 and 21. At the protein level, osteocalcin expression was induced only in the DPSCs on the PCL+FA surfaces at day 21 and then significantly enhanced at day 28. A similar pattern was observed in those specimens stained with Alizarin red and Von Kossa after 21 and 28 days. These data suggest that the incorporation of FA crystals within the three-dimensional PCL nanofiber scaffolds provided a favorable extracellular matrix microenvironment for the growth, differentiation, and mineralization of human DPSCs. This FA-modified PCL nanofiber scaffold shows promising potential for future bone, dental, and orthopedic regenerative applications.

Stem cell‐based pulp tissue engineering: variables enrolled in translation from the bench to the bedside, a systematic review of literature

“…It should act as the original tissue ECM, which provides an adequate environment for the cells by presenting ligand molecules on its surface, guiding cell adhesion and specific migration (Langer & Vacanti 1993). Actually, the use of nanofibres has improved stem cell behaviour as it simulates the spatial arrangement of natural ECM better (Galler et al 2012, Guo et al 2014, Qu et al 2014. Pore distribution, pore size and fibre thickness influence the cell behaviour as well.…”

“…Poly-l-lactic acid (PLLA) nanofibrous scaffolds fabricated by an electrospinning process were believed to be a potential cell carrier in DTE (Deng et al 2007, Guo et al 2012. Actually, the use of nanofibres has improved stem cell behaviour as it simulates the spatial arrangement of natural ECM better (Galler et al 2012, Guo et al 2014, Qu et al 2014. Scaffold pore size refers to the distance between solid sections of the porous matrix (Lawrence & Madihally 2008).…”

“…In the selected studies, the main strategy used was the incorporation of biomolecules (fluorapatite, transforming growth factor b1 (TGFb1), bone morphogenetic protein 2 (BMP-2) and dentine matrix protein 1 (DMP1)) into scaffold structures (Prescott et al 2008, Galler et al 2011a, Cavalcanti et al 2013, Rosa et al 2013, Guo et al 2014, which was more effective than the incorporation of such molecules into culture medium (Abe et al 2008, Gotlieb et al 2008. With regard to physical properties, attempts have been made to control the fibre width to produce nanofibrous polymers such as self-assembly peptides (Deng et al 2007, Galler et al 2008, 2011a, Guo et al 2012, Cavalcanti et al 2013, Rosa et al 2013, Qu et al 2014).…”

Tissue Engineering Approaches for Enamel, Dentin, and Pulp Regeneration: An Update

“…Aside from the attempts for enamel regeneration, stem/progenitor cell-based tissue engineering remains a promising modality for functional dentin regeneration [103][104][105]. A lineage-tracing study proved that new odontoblasts generated during reparative dentinogenesis in teeth come up from the perivascular cells identified by α-smooth muscle actin (αSMA) expression.…”

Densification and Microstructure of Fluorapatite Sintered with Alkaline and Alkaline-Earth Additives

“…Furthermore, it allows mineralization and demineralization of hard tissues [13]. All these properties and others encouraged several researchers to fabricate porous ceramics and composites of FAp [14] [15] [16] [17] [18], while others have been interested in studying glasses ceramics containing FAp [19] [20].…”