Magnetic Nanocomposite Scaffold-Induced Stimulation of Migration and Odontogenesis of Human Dental Pulp Cells through Integrin Signaling Pathways
September
Magnetic Nanocomposite Scaffold-Induced Stimulation of Migration and Odontogenesis of Human Dental Pulp Cells through Integrin Signaling Pathways
Hyung-Mun Yun 0 1
Eui-Suk Lee 0 1
Mi-joo Kim 0 1
Jung-Ju Kim 0 1
Jung-Hwan Lee 0 1
Hae- Hyoung Lee 0 1
Kyung-Ran Park 0 1
Jin-Kyu Yi 0 1
Hae-Won Kim 0 1
Eun-cheol Kim 0 1
0 1 Department of Oral and Maxillofacial Pathology & Research Center for tooth and periodontal tissue regeneration (MRC), School of Dentistry, Kyung Hee University , Seoul , Korea , 2 Department of Oral and Maxillofacial Surgery, Guro Hospital, Korea University , Seoul , Republic of Korea, 3 Institute of Tissue Regeneration Engineering (ITREN), Dankook University , Cheonan , Republic of Korea, 4 Department of Nanobiomedical Science & BK21 PLUS NBM Global Research Center for Regenerative Medicine, Dankook University , Cheonan , Republic of Korea, 5 Department of Biomaterials Science, College of Dentistry, Dankook University , Cheonan , Republic of Korea
1 Editor: Xiaohua Liu, Texas A&M University Baylor College of Dentistry, UNITED STATES
Magnetism is an intriguing physical cue that can alter the behaviors of a broad range of cells. Nanocomposite scaffolds that exhibit magnetic properties are thus considered useful 3D matrix for culture of cells and their fate control in repair and regeneration processes. Here we produced magnetic nanocomposite scaffolds made of magnetite nanoparticles (MNPs) and polycaprolactone (PCL), and the effects of the scaffolds on the adhesion, growth, migration and odontogenic differentiation of human dental pulp cells (HDPCs) were investigated. Furthermore, the associated signaling pathways were examined in order to elucidate the molecular mechanisms in the cellular events. The magnetic scaffolds incorporated with MNPs at varying concentrations (up to 10%wt) supported cellular adhesion and multiplication over 2 weeks, showing good viability. The cellular constructs in the nanocomposite scaffolds played significant roles in the stimulation of adhesion, migration and odontogenesis of HDPCs. Cells were shown to adhere to substantially higher number when affected by the magnetic scaffolds. Cell migration tested by in vitro wound closure model was significantly enhanced by the magnetic scaffolds. Furthermore, odontogenic differentiation of HDPCs, as assessed by the alkaline phosphatase activity, mRNA expressions of odontogenic markers (DMP-1, DSPP,osteocalcin, and ostepontin), and alizarin red staining, was significantly stimulated by the magnetic scaffolds. Signal transduction was analyzed by RT-PCR, Western blotting, and confocal microscopy. The magnetic scaffolds upregulated the integrin subunits (α1, α2, β1 and β3) and activated downstream pathways, such as
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Competing Interests: The authors have declared
that no competing interests exist.
significant impact of magnetic scaffolds in stimulating HDPC behaviors, including cell
migration and odontogenesis, implying the potential usefulness of the magnetic scaffolds
for dentin-pulp tissue engineering.
Regenerative endodontics aims to restore the function of pulp-dentin complex tissues mainly
utilizing dental stem cells with the help of signaling molecules and scaffolding matrices. Scaffold is a
three dimensional (3D) porous framework that serves as a potential biological carrier to facilitate
repopulation of stem cells [1]. Among the scaffolding materials, natural polymers have excellent
biocompatibility, yet they are mechanically fragile and often provoke immune responses [2]. On
the other hand, synthetic polymers mainly those made of polyesters, including polylactic acid
(PLA), polyglycolic acid (PGA), poly lactic-co-glycolic acid (PLGA), and poly-caprolactone
(PCL), are degradable and tissue compatible, yet the cellular activity is still not satisfactory. [3–7].
While the polymeric materials can provide good scaffolding conditions for tissue
regeneration, inorganic additives in nanoparticulate form including hydroxyapatite, tricalcium
phosphate and bioactive glass, have been added to improve the mechanical and biological
properties. Among the nanoparticulate additives, magnetic nanoparticles (MNPs) have
recently gained great interest [8–10]. MNPs exhibit superparamagnetism and respond to
magnetic fields; therefore, the addition of MNPs enables the scaffolds to exhibit magnetic
properties. While the native form of MNPs has been shown poor water dispersibility and some
cellular toxicity at high doses, the surface of MNPs has often been tailored with silica or
surfactant to improve dispersibility and biocompatibility [11, 12].
Because of their intriguing properties, MNPs-added biomaterials have been intensively
studied for the last a few years. Some of the recent works on MNPs-added biomaterials include
MNP-hydroxyapatite ceramics, MNP-calcium phosphate cements and MNP-biopolymer
scaffolds [13–16]. When MNPs were added to bioceramics the bone cell growth and differentiation
have been improved [13]. The magneti (...truncated)