Conditioned Media from Mesenchymal Stem Cells Enhanced Bone Regeneration in Rat Calvarial Bone Defects

Abstract

Tissue engineering has recently become available as a treatment procedure for bone augmentation. However, this procedure has several problems, such as high capital investment and expensive cell culture, complicated safety and quality management issues regarding cell handling, and patient problems with the invasive procedure of cell collection. Moreover, it was reported that stem cells secrete many growth factors and chemokines during their cultivation, which could affect cellular characteristics and behavior. This study investigated the effect of stem-cell-cultured conditioned media on bone regeneration. Cultured conditioned media from human bone marrow-derived mesenchymal stem cells (MSC-CM) enhanced the migration, proliferation, and expression of osteogenic marker genes, such as osteocalcin and Runx2, of rat MSCs (rMSCs) in vitro. MSC-CM includes cytokines such as insulin-like growth factor-1 and vascular endothelial growth factor. In vivo, a prepared bone defect of a rat calvarial model was implanted in five different rat groups using one of the following graft materials: human MSCs/agarose (MSCs), MSC-CM/agarose (MSC-CM), Dulbecco's modified Eagle's medium without serum [DMEM(-)]/agarose [DMEM(-)], PBS/agarose (PBS), and defect only (Defect). After 4 and 8 weeks, implant sections were evaluated using microcomputed tomography (micro-CT) and histological analysis. Micro-CT analysis indicated that the MSC-CM group had a greater area of newly regenerated bone compared with the other groups (p<0.05) and histological analysis at 8 weeks indicated that the newly regenerated bone bridge almost covered the defect. Interestingly, the effects of MSC-CM were stronger than those of the MSC group. In vivo imaging and immunohistochemical staining of transgenic rats expressing green fluorescent protein also showed that migration of rMSCs to the bone defect in the MSC-CM group was greater than in the other groups. These results demonstrated that MSC-CM can regenerate bone through mobilization of endogenous stem cells. The use of stem-cell-cultured conditioned media for bone regeneration is a unique concept that utilizes paracrine factors of stem cells without cell transplantation.

The role of bone marrow aspirate cells in the management of atrophic mandibular fractures by mini-invasive surgical approach: Single-institution experience

“…In support of these statements, other reports of animal models have presented encouraging results. Osugi et al (2012) have shown how MSCs enhance migration, proliferation and osteogenic marker expression in a rat calvarian bone defect model, and this was confirmed by Inukai et al (2013) a few months later. An interesting article stating the capacity of MSCs to regulate the turnover of local bone by a paracrine effect, already mentioned by Herford and Boyne (2008) , was reported in a rat bisphosphonate-related osteonecrosis of the jaw-like model by Ogata et al, 2015 , for which histological analysis confirmed the presence of osteoclasts in the MSC group.…”

“…MSCs have the ability to self-renew and present a multilineage potential (Kan et al, 2005). Their plasticity makes them a promising resource for research in cellular therapy of tissue defects, and several authors have demonstrated how autologous stem cells aspirated from BM can enhance bone healing in in vitro and in vivo studies (Kan et al, 2005;Rickert et al, 2011;Watson et al, 2014;Katagiri et al, 2013;Osugi et al, 2012;Inukai et al, 2013;Kawai et al, 2015;Katagiri et al, 2016). In this regard, osteoinductive growth factors such as bone morphogenic protein (BMP)-2 have been already used with osteoconductive materials to promote bone regeneration (Herford and Boyne, 2008).…”

Adipose Derived Stem Cells Conditioned Media in Combination with Bioceramic-Collagen Scaffolds Improved Calvarial Bone Healing in Hypothyroid Rats

“…Daei-farshbaf et al reported that ADMSC seeded on a bioceramic scaffold promoted calvarial bone healing in hypothyroid rats (23). However, the use of stem cells in tissue engineering for bone regeneration had some problems such as expensive cell culture, complicated cell handling and invasive procedure for cell collection from patients (24). On the other hand, MSC secretes a wide range of bioactive molecules such as growth factors and cytokines that may repair and replace defective tissues and cells (25,26).…”

“…Previous studies have reported that growth factors and cytokines secreted from MSC have high potential for bone regeneration. Osugi et al demonstrated that conditioned medium derived from MSC could promote bone reconstruction by a cooperative effect between IGF-1 and VEGF that influenced osteogenesis and angiogenesis (24). Inukai et al showed a positive effect of multiple cytokines contained in MSC-CM on alveolar bone and cementum regeneration (32).…”

hMSC-Derived VEGF Release Triggers the Chemoattraction of Alveolar Osteoblasts

“…Thus, other mechanisms are suggested to account for the observed tissue regeneration after hMSC administration, including immunomodulation [9,10] and angiogenesis [11], both resulting from the production of multiple paracrine factors by hMSCs [6,7]. The increasing appreciation of hMSCs as trophic mediators [12] manifests in recent concepts which even imply to abandon hMSC administration in favor of using hMSCconditioned culture medium for the purpose of bone regeneration [13][14][15]. The most fundamental mechanism by which hMSCderived paracrine factors are supposed to affect immune and endothelial cells is the attraction of cells to the lesion site [16].…”