First-in-human study and clinical case reports of the alveolar bone regeneration with the secretome from human mesenchymal stem cells
© Katagiri et al. 2016
Received: 25 June 2015
Accepted: 12 January 2016
Published: 15 January 2016
Secreted growth factors and cytokines in the conditioned medium from bone marrow-derived mesenchymal stem cells (MSC-CM) have several effects on cell behavior. Our previous studies revealed that MSC-CM enhances bone regeneration by increasing cell mobilization, angiogenesis, and osteogenesis in vitro and in vivo. This clinical study was undertaken to evaluate the safety and use of MSC-CM for alveolar bone regeneration in eight patients who were diagnosed as needing bone augmentation prior to dental implant placement.
The protocol of this clinical study was approved by the ethics committee of Nagoya University Hospital. MSC-CM was prepared from conditioned medium from commercially available human bone marrow-derived MSCs. Patients were treated with beta-tricalcuim phosphate (β-TCP) or an atelocollagen sponge soaked with MSC-CM. Clinical and radiographic assessments were performed during the follow-up period. Histological assessments were also performed in some cases. Clinical and histological data from patients who underwent the SFE procedure without MSC-CM were also used retrospectively as reference controls.
MSC-CM contained several cytokines such as insulin-like growth factor-1, vascular endothelial growth factor, transforming growth factor-β1, and hepatocyte growth factor in relatively low amounts. No systemic or local complications were reported throughout the study. Radiographic evaluation revealed early bone formation in all cases. Histological evaluation also supported the radiographic findings. Furthermore, infiltration of inflammatory cells was scarce throughout the specimens.
MSC-CM was used safely and with less inflammatory signs and appears to have great osteogenic potential for regenerative medicine of bone. This is the first in-human clinical study of alveolar bone regeneration using MSC-CM.
KeywordsSecretome Mesenchymal stem cells (MSC) Tissue engineering Regenerative medicine Bone
Alveolar bone regeneration with grafting is often carried out prior to placement of dental implants. Several graft materials have been used including autogenous bone, xenogeneic bone, and synthetic bone substitutes. Autogenous bone grafts have been used for a long time with good predictability and are considered the “gold standard” because of their osteoinductive and osteoconductive properties and immunogenic compatibility. However, autogenous bone must be harvested from a donor site of the patient and is associated with higher morbidity [1, 2]. Xenogeneic bone and synthetic bone substitutes such as deproteinized bovine bone, hydroxyapatite, and calcium triphosphate are often used clinically as osteoconductive scaffolds, but they provide limited osteoinductivity and a potential risk of infection and extrusion . Osteoinductive growth factors such as bone morphogenic protein (BMP)-2 have been used with these osteoconductive materials to promote bone regeneration . However, recent studies have indicated unexpected effects on bone regeneration  including induction of a severe inflammatory response, because of the higher dose with clinical application of BMP-2 [6–8].
Recently, the concept of tissue engineering and regenerative medicine has been widely accepted , and many clinical studies have been performed including studies of bone and periodontal regenerative medicine.
We previously developed a technique whereby autogenous human mesenchymal stem cells (hMSCs) from the patient’s bone marrow are combined with platelet-rich plasma for use as an alternative to such materials with predictable good prognosis [10, 11]. However, clinical use of stem cells requires highly qualified safety investigation and quality management of cell handling, and is very expensive. These limitations currently impede the widespread use of stem cells for alveolar bone regeneration therapy. Moreover, recent studies have revealed that the implanted cells do not survive long [12–14]. As an alternative, the effects of the secretomes, the various factors secreted into the medium, from stem cells on tissue repair and regeneration have attracted much attention [15–17].
We have reported the effects of the secretomes in the conditioned medium from bone marrow-derived mesenchymal stem cells (MSC-CM) on bone and periodontal tissue regeneration in vitro and in vivo. MSC-CM contains several cytokines such as insulin-like growth factor (IGF)-1, vascular endothelial growth factor (VEGF), and transforming growth factor (TGF)-β1. MSC-CM enhances cell proliferation, mobilization, angiogenesis, and expression of osteogenic markers such as alkaline phosphatase, collagen type I, and Runx2 genes . MSC-CM also recruits endogenous stem cells to the grafted site and shows early bone and periodontal regeneration in rat calvarial bone defects and dog periodontal bone defects [19–21]. Furthermore, the concentrations of cytokines contained in MSC-CM are relatively low such that use of MSC-CM does not induce the severe histological inflammatory responses that are observed with the clinical use of recombinant human BMP-2 .
Based on these experimental and preclinical studies, we performed a clinical study using MSC-CM for alveolar bone regeneration. Until now, no human study has been reported, and thus, this is the first in-human study using MSC-CM for bone regenerative therapy.
Cell culture and preparation of MSC-CM
Human MSCs were purchased from Lonza Inc. (Walkersville, MD, USA) and cultured in mesenchymal stem cell basal medium (MSCBM; Lonza Inc.) with MSCGM SingleQuots (Lonza Inc.). Cells of the third passage were used in this study. Cells were maintained at 37 °C in 5 % CO2/95 % air.
When hMSCs reached 70 % confluency, the medium was refreshed with 10 ml serum-free Dulbecco’s modified Eagle’s Medium (DMEM; GIBCO, Rockville, MD, USA) containing antibiotics (100 units/ml penicillin G, 100 μg/ml streptomycin, and 0.25 μg/ml amphotericin B; GIBCO). The cell culture-conditioned media were collected after incubation for 48 h. This medium was defined as MSC-CM.
For clinical use, MSC-CM was then concentrated and stored as described below. Briefly, MSC-CM was centrifuged for 5 min at 1500 rpm and then for another 1 min at 15,000 rpm to remove any cells. Five milliliters MSC-CM was mixed with 45 ml 100 % ethanol and incubated at −20 °C for 1 h. The mixture was centrifuged for 15 min at 15,000 rpm at 4 °C, and the supernatant was discarded. The precipitate was suspended again in cold 90 % ethanol and centrifuged for 15 min at 15,000 rpm at 4 °C. The final precipitate was frozen at −80 °C, lyophilized, and stored at −80 °C until use.
To verify the safety, MSC-CM was examined for not only contamination with bacteria, fungi, or mycoplasmas but also virus infection including hepatitis B and C virus, human immunodeficiency virus, and human T-cell leukemia virus before the following procedures.
Enzyme-linked immunosorbent assay (ELISA)
The levels of IGF-1, VEGF, TGF-β1, hepatocyte growth factor (HGF), fibroblast growth factor (FGF)-2, platelet-derived growth factor (PDGF)-BB, BMP-2, and stromal cell-derived factor (SDF)-1α in MSC-CM were investigated using ELISA. The concentration of these factors was measured using a Human Quantikine ELISA kit (R&D Systems, Minneapolis, MN, USA) according to the manufacturer’s instructions. Briefly, 200 μl MSC-CM, DMEM-0 % FBS, or DMEM-30 % FBS were added to 96-well microplates that were coated with a monoclonal antibody recognizing the factor of interest and incubated for 2 h. After washing with phosphate-buffered saline (PBS), a horseradish peroxidase-conjugated antibody against the cytokine or growth factor was added to each well, incubated for 2 h, and washed. Substrate solution was added and incubated for 30 min, and the reaction was terminated by addition of the stop solution. Cytokine levels were determined by measuring the optical density at 450 nm using a microplate spectrophotometer (Benchmark Plus; Bio-Rad, Hercules, CA, USA).
Eight partially edentulous patients who were diagnosed as needing bone augmentation, including maxillary sinus floor elevation (SFE), guided bone regeneration (GBR) and socket preservation (SP), were enrolled in this study. Because of severe alveolar bone atrophy, all the patients had problems with retention of conventional removable dentures, and these procedures and application of dental implants were expected to solve this problem. The criteria for application of these procedures are <5 mm residual bone from the sinus floor to the alveolar ridge in SFE cases and <10 mm of residual bone height in GBR cases.
After routine oral and physical examinations, patients who did not desire to undergo surgery for autogenous bone harvesting were selected for this study. All patients were healthy and free from any disease that may have influenced the outcome of this study (e.g., diabetes, malignant tumor, autoimmune disease, bone disease, endocrine disease). Each patient provided informed consent after receiving detailed information about the surgical procedures, graft materials, alternative treatments, and uncertainties of using a new method. The ethics committee of Nagoya University Hospital approved this research protocol (No.3437). Clinical, radiographic and histological data from two patients who underwent the SFE procedure without MSC-CM were also used retrospectively as reference controls.
Preparation and application of MSC-CM
All surgical procedures were conducted under local anesthesia. The SFE procedure was performed using the lateral window approach . Briefly, a window was created with a round diamond burr at the lateral maxillary sinus wall. After removing the bone, the sinus membrane was elevated. The space created by this procedure was filled with the mixture of MSC-CM and β-TCP (MSC-CM/β-TCP). In cases of simultaneous implant placement, Brånemark MkIII Groovy or NobelActive implants (Nobel Biocare, Zürich, Switwerland) were placed into the alveolar bone at a depth of at least 5 mm according to pre-surgical computer simulation. The lateral window was then covered with a bioabsorbable poly-lactic acid-glycol acid (PLGA) membrane (GC Membrane®, GC, Tokyo, Japan). The mucoperiosteal flap was repositioned and sutured in the usual manner. The GBR procedure was performed after the mucoperiosteal flap was elevated. In cases of simultaneous implant placement, implants were placed in the same manner as described above. Because of the atrophic alveolar bone, exposed threads of the implants were covered with MSC-CM/β-TCP. In SP cases such as tooth extraction sockets, the bone defects were filled with MSC-CM/ACS. After grafting MSC-CM/β-TCP, the grafted areas were covered with PLGA membranes. Lesions grafted with MSC-CM/ACS were not covered with any membranes, and all lesions were closed with a tension-free mucoperiosteal flap. In all cases, the second-stage surgeries were performed about 6 months after implant placement (first-stage surgery). All surgeries were performed by the same surgeon (W.K.).
Clinical and radiographic observations
Cytokines present in MSC-CM
Cytokines detected in MSC-CM
Panorama X-ray and CT images showed early mineralization in the augmented bone. Furthermore, CT images showed that the β-TCP structures gradually become indistinct around 6 months after the first surgery. No bone resorption was observed in any cases, and notable edematous swelling of the maxillary sinus membrane was not obvious throughout the study after the surgery in SFE cases.
Bone biopsies were taken from five cases. Newly formed bone was observed in each specimen. Resorption of β-TCP was found, and replacement with new bone had occurred only 6 months after the first surgery. Furthermore, infiltration of inflammatory cells (e.g., neutrophils, macrophages) was observed less often in these specimens.
Discussion and conclusions
This study evaluated the safety and efficacy of MSC-CM in a human clinical trial for alveolar bone regeneration. Tissue engineering and regenerative medicine of the bone and periodontal tissue using stem cells has begun to be used clinically [10, 23]. We have developed regenerative medicine for bone and periodontal tissue using autogenous bone marrow-derived MSCs, and this approach is considered an alternative to conventional autogenous bone grafting . However, the use of adult stem cells for tissue regeneration has several problems such as safety and quality management in stem cell handling, and the high cost and strict regulation by authorities currently prevent the popularization of this approach. Moreover, permanent engraftment and transdifferentiation of transplanted adult stem cells have not been confirmed . Recent studies have indicated that the therapeutic effects of transplanted stem cells are considered effective for tissue regeneration and for their interesting role as cellular modulators, not just for their multipotent differentiation ability [25, 26].
Transplanted stem cells release several paracrine factors such as cytokines, growth factors, and extracellular matrix molecules that modulate endogenous cellular mobilization, angiogenesis, and cellular differentiation, and induce endogenous stem cells to promote tissue repair and regeneration . Our previous studies revealed that MSC-CM contains several cytokines, such as IGF-1, VEGF, TGF-β1, and HGF, and enhances early bone and periodontal tissue regeneration [18–21]. IGF-1 induces osteoblast proliferation and migration [27, 28] and enhances periodontal regeneration by stimulating periodontal ligament (PDL) cells through the PI3K pathway . VEGF is believed to be the main regulator of angiogenesis, and bone marrow stromal cells secrete sufficient quantities of VEGF to enhance the survival and differentiation of endothelial cells. VEGF also contributes to osteogenesis . TGF-β1 enhances the migration of osteoprogenitor cells, and regulates cell proliferation, differentiation, and extracellular matrix production . TGF-β1 also stimulates PDL regeneration and repair  and is expressed during the development of the alveolar bone, PDL, and cementum . HGF has a direct effect on angiogenesis . A previous study demonstrated that a combination of several factors has an additive effect on cellular migration and osteogenic differentiation . Some studies have investigated a combination of two or more factors to promote bone regeneration [35, 36].
In our study, the advantage of a combination of several factors seems to be versatile effects on bone regeneration. Furthermore, the concentration of each cytokine in MSC-CM may be relatively low and at physiological levels because they were secreted from cells and are not an industrial product such as recombinant BMP-2. BMP-2 has a strong osteoinductive ability, but a high concentration of BMP-2 is required to obtain therapeutic effects on bone regeneration. Cowan et al. suggested that BMP has dose-dependent bone regeneration effects in the rat calvaria model, and the concentration of BMP-2 that induced effective bone regeneration was 240 ng/mm3 . In MSC-CM, the concentration of each cytokine was around hundreds to thousands of picograms per milliliter.
MSC-CM has other effects as well. Ionescu et al. suggested that conditioned medium from MSCs promotes alternative macrophage activation, producing a wound healing/anti-inflammatory M2 phenotype that is due in part to IGF-1 . We found that only a few inflammatory cells were seen where MSC-CM was implanted in our allogeneic animal study [18–21]. In this clinical study, no patient showed abnormal swelling or delayed healing after surgery. β-TCP has been widely used clinically both in orthopedic and maxillofacial lesions and produces excellent osteoconductivity; however, β-TCP is resorbed over a long period . In this study, β-TCP mixed with MSC-CM promoted early resorption and replacement of new bone compared with β-TCP without MSC-CM. This phenomenon may have been due not only to the effects of several cytokines that induced several types of cell behavior and angiogenesis as described above, but also alternative macrophage phenotypes that quickly degraded the scaffold. Badylak et al. investigated the two different types of scaffolds. One was a chemically cross-linked scaffold that did not show any significant degradation during the study period following implantation and that resulted in a predominantly M1-type macrophage response. The other was a non-cross-linked scaffold that was rapidly degraded following implantation and that elicited an M2-type response and showed more constructive regeneration of tissue . From this point of view, the cytokines in MSC-CM are considered to induce the resorption of β-TCP and the switching of the phenotype of macrophages from M1 to M2 at an earlier phase of bone regeneration. Interestingly, implantation of MSC-CM/ACS resulted in denser new bone formation shown as in case 2. ACS is resorbed more easily than β-TCP, and this finding is also consistent with the relationship between the mechanical characteristics of the scaffolds and the phenotype of macrophages.
MSC-CM leads to prominent osteoinductivity according to our series of studies. MSC-CM is required at a relatively low physiological dose to produce therapeutic effects, and it may also have an immunomodulatory effect as described above. Further studies will be required to confirm which individual factors are important and indispensable. This implies the possibility of making new agents using these novel concepts for not only bone and periodontal regeneration but also other systemic diseases that had previously been expected to be treated with transplantation of stem cells.
This is the first-in-human study for alveolar bone regeneration using MSC-CM. Because this study was aimed to assess the safety and response to MSC-CM clinically with a small patients group, we could not deeply show and discuss about the radiographic and histological effects. We have already started the next phase clinical trial to assess the efficacy of MSC-CM on alveolar bone regeneration with more lager patients group. We are planning to report these results will in the future.
conditioned medium from bone marrow-derived mesenchymal stem cells
insulin like growth factor
vascular endothelial growth factor
transforming growth factor
bone morphogenetic protein
hepatocyte growth factor
fibroblast growth factor
platelet-derived growth factor
stromal cell-derived factor
Dulbecco’s modified eagle’s medium
sinus floor elevation
guided bone regeneration
The authors wish to thank Tatsuo Hirai, Hideo Tateishi, Yukako Fukada and Erika Sasaki in Fujieda Heisei Memorial Hospital for their help, encouragement and contributions to the completion of this study. The authors also thank Minoru Ueda, Ryoko Yoshimi and the members of the Department of Oral and Maxillofacial Surgery, Nagoya University Graduate School of Medicine for their assistance. This work was supported in part by Grants-in-Aid for Scientific Research (B) (23592883) from the Ministry of Education, Culture, Sports, and Technology of Japan. None of the authors have any conflicts of interest associated with this study.
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- Arrington ED, Smith WJ, Chambers HG, Bucknell AL, Davino NA. Complications of iliac crest bone graft harvesting. Clin Orthop Relat Res. 1996;329:300–9.PubMedView ArticleGoogle Scholar
- Joshi A, Kostakis GC. An investigation of post-operative morbidity following iliac crest graft harvesting. Br Dent J. 2004;196:167–71.PubMedView ArticleGoogle Scholar
- Damien CJ, Parsons JR. Bone graft and bone graft substitutes: a review of current technology and applications. J Appl Biomater. 1991;2:187–208.PubMedView ArticleGoogle Scholar
- Herford AS, Boyne PJ. Reconstruction of mandibular continuity defects with bone morphogenic protein-2 (rhBMP-2). J Oral Maxillofac Surg. 2008;66:616–24.PubMedView ArticleGoogle Scholar
- Woo EJ. Adverse events reported after the use of recomninant human bone morphogenetic protein 2. J Oral Maxillofac Surg. 2012;70:765–7.PubMedView ArticleGoogle Scholar
- Perri B, Cooper M, Lauryssen C, Anand N. Adverse swelling associated with use of rh-BMP-2 in anterior cervical discectomy and fusion: a case study. Spine J. 2007;7:235–9.PubMedView ArticleGoogle Scholar
- Vaidya R, Carp J, Sethi A, Bartol S, Craig J, Les CM. Complications of anterior cervical discectomy and fusion using recombinant human bone morphogenetic protein-2. Eur Spine J. 2007;16:1257–65.PubMedPubMed CentralView ArticleGoogle Scholar
- Kawasaki K, Aihara M, Honmo J, Sakurai S, Fujimaki Y, Sakamoto K, et al. Effects of reconmbinant human bone morphogenetic protein-2 on differentiation of cells isolated from human bone, muscle, and skin. Bone. 1998;23:223–31.PubMedView ArticleGoogle Scholar
- Langer R, Vacanti JP. Tissue engineering. Science. 1993;260:920–6.PubMedView ArticleGoogle Scholar
- Yamada Y, Ueda M, Naiki T, Takahashi M, Hata K, Nagasaka T. Autogenous injectable bone for regeneration with mesenchymal stem cells (MSCs) and platelet-rich plasma (PRP) – Tissue-engineered bone regeneration. Tissue Eng. 2004;10:955–64.PubMedView ArticleGoogle Scholar
- Yamada Y, Nakamura S, Ito K, Umemura E, Hara K, Nagasaka T, et al. Injectable bonetissue engineeringusingexpanded mesenchymal stem cells. Stem Cells. 2013;31:572–80.PubMedPubMed CentralView ArticleGoogle Scholar
- Muller-Ehmsen J, Whittaker P, Kloner RA, Dow JS, Sakoda T, Long TI, et al. Survival and development of neonatal rat cardiomyocytes transplanted into adult myocardium. J Mol Cell Cardiol. 2002;34:107–16.PubMedView ArticleGoogle Scholar
- Toma C, Wagner WR, Bowry S, Schwartz A, Villanueva F. Fate of culture-expanded mesenchymal stem cells in the microvasculature: in vivo observations of cell kinetics. Circ Res. 2009;104:398–402.PubMedPubMed CentralView ArticleGoogle Scholar
- Ide C, Nakai Y, Nakano N, Seo T, Yamada Y, Endo K, et al. Bone marrow stromal cell transplantation for treatment of sub-acute spinal cord injury in rat. Brain Res. 2010;1332:32–47.PubMedView ArticleGoogle Scholar
- Chen L, Tredget EE, Wu PYG, Wu Y. Paracrine factors of mesenchymal stem cells recruit macrophages and endothelial lineage cells and enhance wound healing. PLoS One. 2008;3:e1886.PubMedPubMed CentralView ArticleGoogle Scholar
- Ciapetti G, Granchi D, Baldini N. The combined use of mesenchymal stromal cells and scaf- folds for bone repair. Curr Pharm Des. 2012;18:1796–820.PubMedView ArticleGoogle Scholar
- Baglio SL, Pegtel DM, Baldini N. Mesenchymal stem cell secreted vesicles provide novel opportunities in (stem) cell-free therapy. Front Physiol. 2012;3:1–11.View ArticleGoogle Scholar
- Katagiri W, Osugi M, Kawai T, Ueda M. Novel cell-free regenerative medicine of bone using stem cell derived factors. Int J Oral Maxillofac Implants. 2013;28:1009–16.PubMedView ArticleGoogle Scholar
- Osugi M, Katagiri W, Yoshimi R, Inukai T, Hibi H, Ueda M. Conditioned media from mesenchymal stem cells enhancedbone regeneration in rat calvarial bone defects. Tissue Eng Part A. 2012;18:14779–1489.View ArticleGoogle Scholar
- Inukai T, Katagiri W, Yoshimi R, Osugi M, Kawai T, Hibi H, et al. Novel application of stem cell-derived factors for periodontal regeneration. Biochem Biophys Res Commun. 2013;430:763–8.PubMedView ArticleGoogle Scholar
- Kawai T, Katagiri W, Osugi M, Sugimura Y, Hibi H, Ueda M. Secretomes from bone marrow-derived mesenchymal stromal cells enhance periodontal tissue regeneration. Cytotherapy. 2015;17:369–81.PubMedView ArticleGoogle Scholar
- Tatum H. Maxillary and sinus implant reconstructions. Dent Clin North Am. 1986;30:207–29.PubMedGoogle Scholar
- Okuda K, Yamamiya K, Kawase T, Mizuno H, Ueda M, Yoshie H. Treatment of human infrabony periodontal defects by grafting human cultured periosteum sheets combined with platelet-rich plasma and porus hydroxyapatite granules: case series. J Int Acad Periodontol. 2009;11:206–13.PubMedGoogle Scholar
- Freyman T, Polin G, Osman H, Crary J, Lu M, Cheng L, et al. A quantitative, randomized study evaluating three methods of mes- enchymal stem cell delivery fol- lowing myocardial infarction. Eur Heart J. 2006;27:1114–22.PubMedView ArticleGoogle Scholar
- Parekkadan B, van Poll D, Suganuma K, Carter EA, Berthiaume F, Tilles AW, et al. Mesenchymal stem cell-derived molecules reverse fulminant hepatic failure. PLoS One. 2007;2:e941.PubMedPubMed CentralView ArticleGoogle Scholar
- Lee JK, Jin HK, Endo S, Schuchman EH, Carter JE, Bae JS. Intracerebral trans- plantation of bone marrow-derived mesenchymal stem cells reduces amyloid-beta deposition and res- cues memory deficits in Alzheimer’s disease mice by modulation of immune responses. Stem Cells. 2010;28:329–43.PubMedGoogle Scholar
- Cornish J, Grey A, Callon KE, Naot D, Hill BL, Lin CQ, et al. Shared pathways of osteoblast mitogenesis induced by amylin, adrenomedullin, and IGF-1. Biochem Biophys Res Commun. 2004;318:240–6.PubMedView ArticleGoogle Scholar
- Li Y, Yu X, Lin S, Li X, Zhang S, Song YH. Insulin-like growth factor 1 enhances the migratory capacity of mesenchymal stem cells. Biochem Biophys Res Commun. 2007;356:780–4.PubMedView ArticleGoogle Scholar
- Han X, Amar S. Role of insulin-like growth factor-1 signaling in dental fibroblast apoptosis. J Periodontol. 2003;74:1176–82.PubMedView ArticleGoogle Scholar
- Kaiglar D, Krebsbach PH, West ER, Horger K, Huang YC, Mooney DJ. Endothelial cell modulation of bone marrow stromal cell osteogenic potential. FASEB J. 2005;19:665–7.Google Scholar
- Bostrom MP, Asnis P. Transforming growth factor beta in fracture repair. Clin Orthop Relat Res. 1998;355:S124–131.PubMedView ArticleGoogle Scholar
- Fujita T, Shiba H, van Dyke TE, Kurihara H. Differential effects of growth factors and cytokines on the synthesis of SPARC, DNA, fibronectin and alkaline phosphatase activity in human periodontal ligament cells. Cell Biol Int. 2004;28:281–6.PubMedView ArticleGoogle Scholar
- Gao J, Symons AL, Bartold PM. Expression of transforming growth factor-beta 1 (TGF-beta1) in the developing periodontium of rats. J Dent Res. 1998;77:1708–16.PubMedView ArticleGoogle Scholar
- Morishita R, Nakamura S, Hayashi S, Taniyama Y, Moriguchi A, Nagono T, et al. Therapeutic angiogenesis induced by human recombinant hepatocyte growth factor in rabbit hind limb ischemia model as cytokine supplement therapy. Hypertension. 1999;33:1379–84.PubMedView ArticleGoogle Scholar
- Ozaki Y, Nishimura M, Sekiya K, Suehiro F, Kanawa M, Nikawa H, et al. Comprehensive analysis of chemotactic factors for bone marrow mesenchymal stem cells. Stem Cells Dev. 2007;16:119–29.PubMedView ArticleGoogle Scholar
- Chen L, Jiang W, Huang J, He B, Zuo G, Zhang W, et al. Insulin-like growth factor 2 (IGF-2) potentiates BMP-9-induced osteogenic differentiation and bone formation. J Bone Miner Res. 2010;25:2447–59.PubMedPubMed CentralView ArticleGoogle Scholar
- Cowan CM, Aghaloo T, Chou YF, Walder B, Zhang X, Soo C, et al. MicroCT evaluation of three-dimensional mineralization in response to BMP-2 doses in vitro and in critical sized rat calvarial defects. Tissue Eng. 2007;13:501–12.PubMedView ArticleGoogle Scholar
- Ionescu L, Byrne RN, van Haaften T, Vadivel A, Alphonse RS, Rey-Parra GJ, et al. Stem cell conditioned medium improves acute lung injury in mice: in vivo evidence for stem cell paracrine action. Am J Physiol Lung Cell Mol Physiol. 2012;303:L967–977.PubMedPubMed CentralView ArticleGoogle Scholar
- Zerbo IR, Zijderveld SA, De Boer A, Bronckers ALJJ, De Lange G, Bruggenkate CMT, et al. Histomorphometry of human sinus floor augmentation using a porous β-tricalcium phosphate: a prospective study. Clin Oral Implants Res. 2004;15:724–32.PubMedView ArticleGoogle Scholar
- Badylak SF, Valentin JE, Ravindra AK, McCabe GP, Stewart-Akers AM. Macrophage phenotype as a determinant of biologic scaffold remodeling. Tissue Eng Part A. 2008;14:1835–42.PubMedView ArticleGoogle Scholar