Enamel Matrix Derivative Promotes Human Periodontal Ligament Cell Differentiation and Osteoprotegerin Production in vitro

The Potential of Enamel Matrix Derivative in Countering Bisphosphonate-Induced Effects in Osteoblasts

The suppressive effect of bisphosphonates (BPs) on bone metabolism is considered to be a major cause of medication-related osteonecrosis of the jaw (MRONJ). Enamel matrix derivative (EMD) stimulates and activates growth factors, leading to the regeneration of periodontal tissues. In this study, we aimed to explore the potential of EMD in reversing the detrimental effects of BPs on human fetal osteoblasts (hFOBs) and osteosarcoma-derived immature osteoblasts (MG63s) by assessing cell viability, apoptosis, migration, gene expression, and protein synthesis. While the suppressive effect of zoledronate (Zol) on cell viability and migration was observed, the addition of EMD significantly mitigated this effect and enhanced cell viability and migration. Furthermore, an increased apoptosis rate induced by Zol was decreased with the addition of EMD. The decreased gene expression of alkaline phosphatase (ALP), osteocalcin (OC), and the receptor activator of nuclear factors kappa-B ligand (RANKL) caused by BP treatment was reversed by the co-addition of EMD to hFOB cells. This trend was also observed for ALP and bone sialoprotein (BSP) levels in MG63 cells. Furthermore, suppressed protein levels of OC, macrophage colony-stimulating factor (M-CSF), BSP, and type 1 collagen (COL1) were recovered following the addition of EMD. This finding suggests that EMD could mitigate the effects of BPs, resulting in the recovery of cell survival, migration, and gene and protein expression. However, the behavior of the osteoblasts was not fully restored, and further studies are necessary to confirm their effects at the cellular level and to assess their clinical usefulness in vivo for the prevention and treatment of MRONJ.

Enamel Matrix Derivative (EMD) as an Adjunct to Non-surgical Periodontal Therapy: A Systematic Review

If left untreated, periodontitis is a chronic, irreversible disease that can contribute to tooth loss. The primary objective of periodontal treatment is to arrest the progression of the disease and restore the supporting structures of the tooth. Scaling and root planing (SRP) is a common non-surgical periodontal therapy (NSPT) used to reduce inflammation, pocket depth, and clinical attachment loss. However, NSPT has limitations, notably in difficult-to-access deep pockets and molar furcations. Deep pockets (greater than 4 mm) frequently retain calculus following NSPT. To attain direct access, surgical periodontal therapy (SPT) is recommended, particularly for pockets deeper than 5 mm. Enamel matrix derivative (EMD) has emerged in recent years as a tool for periodontal regeneration when used in conjunction with NSP for infrabony defects. EMD may also have advantageous effects when combined with NSPT. The purpose of this review is to provide a thorough understanding of the effects of EMD as an adjunct to NSPT. The databases Scopus, PubMed/MEDLINE, Google Scholar, Cochrane, and Embase were systematically searched to identify relevant studies on the benefits of EMD and its use as an adjunct to NSPT. Incorporating EMD into NSPT reduces chair time, and 60% of studies demonstrated considerable benefits compared to SRP alone, according to the findings. On the basis of research, it can be concluded that EMD can be used as an adjunct to NSPT, thereby reducing the amount of time spent in the operating chair. In some cases, it can, therefore, be regarded as an alternative to surgical treatment.

Biocompatibility and Osteogenic Potential of Calcium Silicate-Based Cement Combined with Enamel Matrix Derivative: Effects on Human Bone Marrow-Derived Stem Cells

The characteristics of retrograde filling material are important factors that can affect the long-term success of apical microsurgery. Various calcium silicate-based cements (CSC) were introduced to overcome drawbacks of mineral trioxide aggregate (MTA), while Emdogain is known to be effective in the regeneration of periodontal tissues. The aim of this study is to evaluate the biocompatibility and osteogenic potential of various CSCs combined with Emdogain on human bone marrow-derived mesenchymal stem cells. Experimental groups were classified into eight groups depending on the material and the presence of Emdogain. In the cell-counting kit test, all experimental groups combined with Emdogain showed higher cell viability compared with those without Emdogain at days 1 and 2. In the wound-healing assay, cell migration increased significantly over time, with or without Emdogain. In the alkaline phosphatase assay, all groups treated with Emdogain showed higher activity compared with those without Emdogain at day 3 (p < 0.05). Using alizarin red S staining, all groups treated with Emdogain showed greater calcium nodule formation compared with those without Emdogain at days 7 and 14 (p < 0.05). In conclusion, using CSCs as retrograde filling materials and the application of additional Emdogain will increase bone regeneration and improve the prognosis of apical microsurgery.

Enamel matrix proteins regulate hypoxia-induced cellular biobehavior and osteogenic differentiation in human periodontal ligament cells

Hypoxia is a crucial microenvironment for inflamed periodontal tissue and periodontal wound healing. Enamel matrix proteins (EMPs) potentially can promote the formation of new periodontium. The effects of EMPs on periodontal ligament cells under hypoxia, however, remain unclear. We investigated the effects of EMPs on cellular biobehavior and osteogenic differentiation of human periodontal ligament cells (hPDLCs) under hypoxia. Under cobalt chloride (CoCl₂)-induced hypoxia, cellular biobehavior of hPDLCs, including proliferation, attachment, spreading, and migration with or without EMPs, was evaluated by 3-(4, 5-dimethylthiazol- 2-yl)-2, 5-diphenyl tetrazolium bromide (MTT), cell counting, spreading area measurement and wound scratch assay. The osteogenic activity of hPDLCs was assessed using alkaline phosphatase (ALP) and alizarin red S staining (ARS). The expressions of osteogenic genes including runt related transcription factor 2 (Runx2), ALP, osteocalcin (OCN) and collagen type I (Col-I) were detected using real time quantitative PCR, western blot and immunocytochemistry assays. The biobehavior and osteogenic differentiation of hPDLCs were inhibited significantly under hypoxia. EMPs have no effect on cell proliferation under mimicked hypoxia. EMPs partly reversed the inhibitory effects of hypoxia, however, for other cellular biobehavior including attachment, spreading and migration, and markedly up-regulated osteogenic differentiation activities including ALP, mineralization ability and the expressions of osteogenic genes such as Runx2, ALP, osteocalcin, and collagen type I in hPDLCs under hypoxia. EMPs attenuate the hypoxic injury to cellular biobehavior and osteogenic differentiation in hPDLCs under hypoxia.

Enamel matrix derivative enhances the proliferation and osteogenic differentiation of human periodontal ligament stem cells on the titanium implant surface

Periodontal ligament stem cells (PDLSCs) have mesenchymal-stem-cells-like qualities, and are considered as one of the candidates of future clinical application in periodontal regeneration therapy. Enamel matrix derivative (EMD) is widely used in promoting periodontal regeneration. However, the effects of EMD on the proliferation and osteogenic differentiation of human PDLSCs grown on the Ti implant surface are still no clear. Therefore, this study examined the effects of EMD on human PDLSCs in vitro. Human PDLSCs were isolated from healthy participants, and seeded on the surface of Ti implant disks and stimulated with various concentrations of EMD. Cell proliferation was determined with Cell Counting Kit-8 (CCK-8). The osteogenic differentiation of PDLSCs was evaluated by the measurement of alkaline phosphatase (ALP) activity, Alizarin red staining, and real-time polymerase chain reaction (qRT-PCR) and Western blotting, respectively. The results indicated that EMD at concentrations (5-60 µg/ml) increased the viability and proliferation of PDLSCs. The treatment with 30 and 60 µg/ml of EMD significantly elevated ALP activity, augmented mineralized nodule formation and calcium deposition, and upregulated the mRNA and protein levels of Runx-2 and osteocalcin (OCN) in the PDLSCs grown on the Ti surface. Further investigation found that EMD treatment did not change the protein levels of phosphatidylinositol-3-kinase (PI3K), p-PI3K, Akt and mTOR, but significantly upregulated the phosphorylated levels of Akt and mTOR. Collectively, these results suggest that EMD stimulation can promote the proliferation and osteogenic differentiation of PDLSCs grown on Ti surface, which is possibly associated with the activation of Akt/mTOR signaling pathway.

The Influence of Arginine on the Response of Enamel Matrix Derivative (EMD) Proteins to Thermal Stress: Towards Improving the Stability of EMD-Based Products

In a current procedure for periodontal tissue regeneration, enamel matrix derivative (EMD), which is the active component, is mixed with a propylene glycol alginate (PGA) gel carrier and applied directly to the periodontal defect. Exposure of EMD to physiological conditions then causes it to precipitate. However, environmental changes during manufacture and storage may result in modifications to the conformation of the EMD proteins, and eventually premature phase separation of the gel and a loss in therapeutic effectiveness. The present work relates to efforts to improve the stability of EMD-based formulations such as Emdogain^™ through the incorporation of arginine, a well-known protein stabilizer, but one that to our knowledge has not so far been considered for this purpose. Representative EMD-buffer solutions with and without arginine were analyzed by 3D-dynamic light scattering, UV-Vis spectroscopy, transmission electron microscopy and Fourier transform infrared spectroscopy at different acidic pH and temperatures, T, in order to simulate the effect of pH variations and thermal stress during manufacture and storage. The results provided evidence that arginine may indeed stabilize EMD against irreversible aggregation with respect to variations in pH and T under these conditions. Moreover, stopped-flow transmittance measurements indicated arginine addition not to suppress precipitation of EMD from either the buffers or the PGA gel carrier when the pH was raised to 7, a fundamental requirement for dental applications.

Enamel matrix derivative, inflammation and soft tissue wound healing

Over 15 years have now passed since enamel matrix derivative (EMD) emerged as an agent capable of periodontal regeneration. Following thorough investigation, evidenced-based clinical application is now established for a multitude of clinical settings to promote regeneration of periodontal hard tissues. Despite the large number of studies and review articles written on this topic, no single review has compiled the influence of EMD on tissue inflammation, an area of research that merits substantial attention in periodontology. The aim of the present review was to gather all studies that deal with the effects of EMD on tissue inflammation with particular interest in the cellular mechanisms involved in inflammation and soft tissue wound healing/resolution. The effects of EMD on monocytes, macrophages, lymphocytes, neutrophils, fibroblasts and endothelial cells were investigated for changes in cell behavior as well as release of inflammatory markers, including interleukins, prostaglandins, tumor necrosis factor-α, matrix metalloproteinases and members of the OPG-RANKL pathway. In summary, studies listed in this review have reported that EMD is able to significantly decrease interleukin-1b and RANKL expression, increase prostaglandin E2 and OPG expression, increase proliferation and migration of T lymphocytes, induce monocyte differentiation, increase bacterial and tissue debris clearance, as well as increase fibroplasias and angiogenesis by inducing endothelial cell proliferation, migration and capillary-like sprout formation. The outcomes from the present review article indicate that EMD is able to affect substantially the inflammatory and healing responses and lay the groundwork for future investigation in the field.

Cellular viability and genetic expression of human gingival fibroblasts to zirconia with enamel matrix derivative (Emdogain®)

PURPOSE

The objective of this study was to investigate the biologic effects of enamel matrix derivative (EMD) with different concentrations on cell viability and the genetic expression of human gingival fibroblasts (HGF) to zirconia surfaces.

MATERIALS AND METHODS

Immortalized human gingival fibroblasts (HGF) were cultured (1) without EMD, (2) with EMD 25 µg/mL, and (3) with EMD 100 µg/mL on zirconia discs. MTT assay was performed to evaluate the cell proliferation activity and SEM was carried out to examine the cellular morphology and attachment. The mRNA expression of collagen type I, osteopontin, fibronectin, and TGF-β1 was evaluated with the real-time polymerase chain reaction (RT-PCR).

RESULTS

From MTT assay, HGF showed more proliferation in EMD 25 µg/mL group than control and EMD 100 µg/mL group (P<.05). HGFs showed more flattened cellular morphology on the experimental groups than on the control group after 4h culture and more cellular attachments were observed on EMD 25 µg/mL group and EMD 100 µg/mL group after 24h culture. After 48h of culture, cellular attachment was similar in all groups. The mRNA expression of type I collagen increased in a concentration dependent manner. The genetic expression of osteopontin, fibronectin, and TGF-β1 was increased at EMD 100 µg/mL. However, the mRNA expression of proteins associated with cellular attachment was decreased at EMD 25 µg/mL.

CONCLUSION

Through this short term culture of HGF on zirconium discs, we conclude that EMD affects the proliferation, attachment, and cell morphology of HGF cells. Also, EMD stimulates production of extracellular matrix collagen, osteopontin, and TGF-β1 in high concentration levels.

CLINICAL RELEVANCE

With the use of EMD, protective barrier between attached gingiva and transmucosal zirconia abutment may be enhanced leading to final esthetic results with implants.

Effects of enamel matrix derivative on the proliferation and osteogenic differentiation of human gingival mesenchymal stem cells

INTRODUCTION

Gingiva-derived mesenchymal stem cells (GMSCs) have recently been harvested and applied for rebuilding lost periodontal tissue. Enamel matrix derivative (EMD) has been used for periodontal regeneration and the formation of new cementum with inserting collagen fibers; however, alveolar bone formation is minimal. Recently, EMD has been shown to enhance the proliferation and mineralization of human bone marrow mesenchymal stem cells. Because the gingival flap is the major component to cover the surgical wound, the effects of EMD on the proliferation and mineralization of GMSCs were evaluated in the present study.

METHODS

After single cell suspension, the GMSCs were isolated from the connective tissues of human gingiva. The colony forming unit assay of the isolated GMSCs was measured. The expression of stem cell markers was examined by flow cytometry. The cellular telomerase activity was identified by polymerase chain reaction (PCR). The osteogenic, adipogenic and neural differentiations of the GMSCs were further examined. The cell proliferation was determined by MTS assay, while the expression of mRNA and protein for mineralization (including core binding factor alpha, cbfα-1; alkaline phosphatase, ALP; and osteocalcin, OC; ameloblastin, AMBN) were analyzed by real time-PCR, enzyme activity and confocal laser scanning microscopy.

RESULTS

The cell colonies could be easily identified and the colony forming rates and the telomerase activities increased after passaging. The GMSCs expressed high levels of surface markers for CD73, CD90, and CD105, but showed low expression of STRO-1. Osteogenic, adipogenic and neural differentiations were successfully induced. The proliferation of GMSCs was increased after EMD treatment. ALP mRNA was significantly augmented by treating with EMD for 3 hours, whereas AMBN mRNA was significantly increased at 6 hours after EMD treatment. The gene expression of OC was enhanced at the dose of 100 μg/ml EMD at day 3. Increased protein expression for cbfα-1 at day 3, for ALP at day 5 and 7, and for OC at week 4 after the EMD treatments were observed.

CONCLUSIONS

Human GMSCs could be successfully isolated and identified. EMD treatments not only induced the proliferation of GMSCs but also enhanced their osteogenic differentiation after induction.

Effects of enamel matrix proteins on multi-lineage differentiation of periodontal ligament cells in vitro

The adult periodontal ligament (PDL) is considered to contain progenitor cells that are involved in the healing of periodontal wounds. Treatment with enamel matrix derivative (EMD), a heat-treated preparation derived from enamel matrix proteins (EMPs), has been shown to be of some clinical benefit in eliciting periodontal regeneration in vivo. Although there is extensive information available about the effects of EMD on periodontal regeneration, the precise influence of this material on alveolar bone and the formation of blood vessels and proprioceptive sensory nerves, prominent features of functionally active periodontal tissue, remain unclear. The aim of the present study was therefore to examine the effects of EMD on the ability of human periodontal ligament cells (HPCs) to undergo multi-lineage differentiation in vitro. Our results showed that HPCs treated with EMD under non-selective growth conditions did not show any evidence of osteogenic, adipogenic, chondrogenic, neovasculogenic, neurogenic and gliogenic "terminal" differentiation. In contrast, under selective lineage-specific culture conditions, EMD up-regulated osteogenic, chondrogenic and neovasculogenic genes and "terminal" differentiation, but suppressed adipogenesis, neurogenesis and gliogenesis. These findings thus demonstrate for the first time that EMD can differentially modulate the multi-lineage differentiation of HPCs in vitro.

Differential effect of amelogenin peptides on osteogenic differentiation in vitro: identification of possible new drugs for bone repair and regeneration

Enamel matrix proteins (EMP) have been shown to promote regeneration of periodontal ligament and root cementum, and sometimes to enhance the differentiation of bone-forming cells in vitro and new bone growth in vivo. However, the inconsistent and unpredictable effects of EMP that have been reported for bone regeneration may be due to the highly variable composition of this heterogeneous material, which is comprised mainly of amelogenin and amelogenin-derived peptides. The present study has therefore examined the effects of naturally occurring low-molecular-weight (LMW) and high-molecular-weight (HMW) fractions of Emdogain(®) (EMD; Institut Straumann, Basel, Switzerland), a commercially available form of EMP, on osteogenic differentiation of bone precursor cells in vitro. In addition, the effects of chemically synthesized specific components of LMW and HMW-namely, the tyrosine-rich amelogenin peptide (TRAP), a specific amelogenin isoform derived by proteolytic clipping, and a leucine-rich amelogenin peptide (LRAP), an isoform derived by alternative splicing-on bone-forming cell activity were also investigated. Our findings demonstrate that while TRAP suppressed the formation of bone-like mineralized nodules, LRAP upregulated osteogenic differentiation. Furthermore, synthetically produced TRAP and its unique C-terminal 12 amino acid sequence (TCT) also suppressed bone-forming cells, whereas LRAP and its unique C-terminal 23 amino acid sequence (LCT) markedly enhanced terminal differentiation of bone-forming cells. These findings suggest that the differential effects of amelogenin-derived peptide sequences present in EMP could be of potential clinical value, with the novel bioactive TCT peptide as a useful tool for limiting pathological bone cell growth and the unique LCT sequence having therapeutic benefits in the treatment of periodontal and orthopedic diseases.

Enamel matrix derivative: a review of cellular effects in vitro and a model of molecular arrangement and functioning

BACKGROUND

Enamel matrix derivative (EMD), the active component of Emdogain®, is a viable option in the treatment of periodontal disease owing to its ability to regenerate lost tissue. It is believed to mimic odontogenesis, though the details of its functioning remain the focus of current research.

OBJECTIVE

The aim of this article is to review all relevant literature reporting on the composition/characterization of EMD as well as the effects of EMD, and its components amelogenin and ameloblastin, on the behavior of various cell types in vitro. In this way, insight into the underlying mechanism of regeneration will be garnered and utilized to propose a model for the molecular arrangement and functioning of EMD.

METHODS

A review of in vitro studies of EMD, or components of EMD, was performed using key words "enamel matrix proteins" OR "EMD" OR "Emdogain" OR "amelogenin" OR "ameloblastin" OR "sheath proteins" AND "cells." Results of this analysis, together with current knowledge on the molecular composition of EMD and the structure and regulation of its components, are then used to present a model of EMD functioning.

RESULTS

Characterization of the molecular composition of EMD confirmed that amelogenin proteins, including their enzymatically cleaved and alternatively spliced fragments, dominate the protein complex (>90%). A small presence of ameloblastin has also been reported. Analysis of the effects of EMD indicated that gene expression, protein production, proliferation, and differentiation of various cell types are affected and often enhanced by EMD, particularly for periodontal ligament and osteoblastic cell types. EMD also stimulated angiogenesis. In contrast, EMD had a cytostatic effect on epithelial cells. Full-length amelogenin elicited similar effects to EMD, though to a lesser extent. Both the leucine-rich amelogenin peptide and the ameloblastin peptides demonstrated osteogenic effects. A model for molecular structure and functioning of EMD involving nanosphere formation, aggregation, and dissolution is presented.

CONCLUSIONS

EMD elicits a regenerative response in periodontal tissues that is only partly replicated by amelogenin or ameloblastin components. A synergistic effect among the various proteins and with the cells, as well as a temporal effect, may prove important aspects of the EMD response in vivo.

The role of cell surface markers and enamel matrix derivatives on human periodontal ligament mesenchymal progenitor responses in vitro

Periodontitis is a chronic-, infectious-disease of the human periodontium that is characterized by the loss of supporting tissues surrounding the tooth such as the periodontal ligament (PDL), cementum and alveolar bone. Regeneration of the periodontium is dependent on the participation of mesenchymal stem/stromal cells (MSC) resident in the PDL. Enamel matrix derivative (EMD), an extract from immature porcine enamel rich in amelogenin protein but that also contain bone morphogenetic protein (BMP), is used to treat periodontal defects. The effects of EMD on MSC cells of the PDL are not well characterized. In this in vitro study, we identify PDL progenitor cells from multiple individuals and demonstrate that EMD stimulates them. We show that the effect of EMD on cell proliferation and migration is mediated through the amelogenin it contains, while the differentiation of these progenitor cells to cell types of mineralized tissue is mainly due to BMP signaling.

Effect of coating Straumann Bone Ceramic with Emdogain on mesenchymal stromal cell hard tissue formation

Periodontal tissue engineering requires a suitable biocompatible scaffold, cells with regenerative capacity, and instructional molecules. In this study, we investigated the capacity of Straumann Bone Ceramic coated with Straumann Emdogain, a clinical preparation of enamel matrix protein (EMP), to aid in hard tissue formation by post-natal mesenchymal stromal cells (MSCs) including bone marrow stromal cells (BMSCs) and periodontal ligament fibroblasts (PDLFs). MSCs were isolated and ex vivo-expanded from human bone marrow and periodontal ligament and, in culture, allowed to attach to Bone Ceramic in the presence or absence of Emdogain. Gene expression of bone-related proteins was investigated by real time RT-PCR for 72 h, and ectopic bone formation was assessed histologically in subcutaneous implants of Bone Ceramic containing MSCs with or without Emdogain in NOD/SCID mice. Alkaline phosphatase activity was also assessed in vitro, in the presence or absence of Emdogain. Collagen-I mRNA was up-regulated in both MSC populations over the 72-h time course with Emdogain. Expression of BMP-2 and the osteogenic transcription factor Cbfa-1 showed early stimulation in both MSC types after 24 h. In contrast, expression of BMP-4 was consistently down-regulated in both MSC types with Emdogain. Up-regulation of osteopontin and periostin mRNA was restricted to BMSCs, while higher levels of bone sialoprotein-II were observed in PDLFs with Emdogain. Furthermore, alkaline phosphatase activity levels were reduced in both BMSCs and PDLFs in the presence of Emdogain. Very little evidence was found for ectopic bone formation following subcutaneous implantation of MSCs with Emdogain-coated or -uncoated Bone Ceramic in NOD/SCID mice. The early up-regulation of several important bone-related genes suggests that Emdogain may have a significant stimulatory effect in the commitment of mesenchymal cells to osteogenic differentiation in vitro. While Emdogain inhibited AP activity and appeared not to induce ectopic bone formation, longer-term studies are required to determine whether it promotes the final stages of osteoblast formation and mineralization at gene and protein levels. While used in clinical applications, whether Emdogain and other commercial preparations of EMPs truly possess the capacity to induce the regeneration of bone or other components of the periodontium remains to be established.

Porcine tooth germ cell conditioned medium can induce odontogenic differentiation of human dental pulp stem cells

It is suggested that the differentiation of tooth-derived stem cells is modulated by the local microenvironment in which they reside. Previous studies have indicated that tooth germ cell-conditioned medium (TGC-CM) holds the potential to induce dental pulp stem cells (DPSCs) to differentiate into the odontogenic lineage. Nevertheless, human TGC-CM (hTGC-CM) is not feasible in practical application, so we conjectured that xenogenic TGC-CM might exert a similar influence on human dental stem cells. In this study, we chose swine as the xenogenic origin and compared the effect of porcine tooth germ cell-conditioned medium (pTGC-CM) with its human counterpart on human DPSCs. Morphological appearance, colony-forming assay, in vitro multipotential ability, protein and gene expression of the odontogenic phenotype and the in vivo differentiation capacity of DPSCs were evaluated. The results showed that pTGC-CM exerted a similar effect to hTGC-CM in inducing human DPSCs to present odontogenic changes, which were indicated by remarkable morphological changes, higher multipotential capability and the expression of some odontogenic markers in gene and protein levels. Besides, the in vivo results showed that pTGC-CM-treated DPSCs, similar to hTGC-CM-treated DPSCs, could form a more regular dentine-pulp complex. Our data provided the first evidence that pTGC-CM is able to exert almost the same effect on DPSCs with hTGC-CM. The observations suggest that the application of xenogenic TGC-CM may facilitate generating bioengineered teeth from tooth-derived stem cells in future.

Emdogain in carcinogenesis: a systematic review of in vitro studies

Emdogain is a commercial product of unknown composition and is clinically used to induce periodontal regeneration. This study aims to review current knowledge of the in vitro effects of Emdogain on oral tissues and, in particular, factors related to carcinoma. A systematic approach was used to review studies from the Embase and Pubmed databases; a total of 76 studies were included. These comprised in vitro studies of the cytokines in, or regulated by, Emdogain and assays designed to study the effects of EMD on human cells in oral tissues or malignant cells. Several studies have shown that EMD regulates the proliferation, migration, adhesion, gene expression, and cytokine production of (pre-)osteoblasts, periodontal fibroblasts, and gingival fibroblasts. However, the effects of EMD on malignant oral cells are not well understood. EMD seems to have broad regulatory effects on malignant cells and on several carcinoma-related factors. Evidence suggests that patients with premalignant or malignant mucosal lesions should not be treated with EMD.

Stimulation of cytokines in osteoblasts cultured on enamel matrix derivative

OBJECTIVE

The purpose of this study was to evaluate the influence of enamel matrix derivative (EMD) on the release of transforming growth factor beta 1 (TGF-beta1), interleukin-6 (IL-6), insulin-like growth factor I (IGF-I), bone morphogenetic protein 2 (BMP-2), and osteoprotegerin (OPG) in human and mouse osteoblasts.

STUDY DESIGN

Human MG-63 and mouse MC3T3-E1 cells were seeded onto 6-well culture plates at an initial density of 5,000/cm(2) and grown in Dulbecco's eagle medium (DMEM) with 10% fetal bovine serum for 24 h. Then cells were cultured either with 100 microg/mL EMD added to DMEM or with DMEM only. After 2, 5, and 9 days' incubation the culture medium was collected and analyzed by enzyme-linked immunosorbent analysis. Data were analyzed using Student t test.

RESULTS

The EMD treatment significantly increased the production of IL-6 and TGF-beta1 (P < .05) at all time points. The release of OPG was also increased in mouse osteoblasts (P < .05). IGF-I and BMP-2 were not detected in both control and EMD-treated groups.

CONCLUSION

This study suggests that the stimulatory effects of EMD on tissue regeneration are mediated by the up-regulation of local mediators released by osteoblasts.