3D Bone Biomimetic Scaffolds for Basic and Translational Studies with Mesenchymal Stem Cells. Int J Mol Sci. 2018;19. [PMID: 30322134 PMCID: PMC6213614 DOI: 10.3390/ijms19103150]

Mesenchymal stem cells aligned and stretched in self-assembling peptide hydrogels

The presented research highlights a novel approach using fmoc-protected peptide hydrogels for the encapsulation and stretching of mesenchymal stem cells (MSCs). This study utilized a custom mechanical stretching device with a PDMS chamber to stretch human MSCs encapsulated in Fmoc hydrogels. The study assessed the influence of various solvents on the self-assembly and mechanical properties of the hydrogels, and MSC viability and alignment. Particularly we focused on fluorenylmethoxycarbonyl-diphenylalanine (Fmoc-FF) prepared in dimethyl sulfoxide (DMSO), hexafluoro-2-propanol (HFP), and deionized water (DiH2O). Through molecular self-assembly of the peptide sequence into β-sheets connected by π-π aromatic stacking of F-F groups, the peptide hydrogel was found to form a stiff, hydrated gel with nanofiber morphology and a compressive modulus ranging from 174 to 277 Pa. Therefore, this hydrogel can mimic certain critical features of the extracellular matrix and collagen. Evaluations of MSCs cultured on the peptide hydrogels, including viability, morphology, and alignment assessments using various staining techniques, demonstrated that 3D-cultured MSCs in Fmoc-FF/HFP and Fmoc-FF/DMSO, followed by mechanical stretching, exhibited elongated morphology with distinct microfilament fibers compared to the control cells, which maintained a round and spherical F-actin shape. Notably, peptide gels with a concentration of 5 mM maintained 100 % MSC viability. The findings indicate the potential and specific conditions for successful cell encapsulation and alignment within peptide hydrogels, highlighting a promising tissue engineering platform through the encapsulation of MSCs in peptide nanofibers followed by a stretching process. By enhancing our understanding of MSC-peptide hydrogel interactions, this research contributes to the development of biomaterials tailored for regenerative medicine.

Human alveolar bone-derived mesenchymal stem cell cultivation on a 3D-printed PDLLA scaffold for bone formation

This study aimed to assess effects of 3-dimensionally (3D) printed poly-d,l-lactin (PDLLA) on human alveolar bone-derived mesenchymal stem cell (h-ABMSC) osteogenic proliferation and differentiation. Human ABMSCs were cultured and identified using flow cytometry and morphological analysis. Control and PDLLA experimental groups were assessed using a Cell Counting Kit-8 (CCK-8) to detect cellular cytotoxicity and proliferative activity. Real-time quantitative polymerase chain reaction was used to determine expression levels of osteogenesis genes including alkaline phosphatase (ALP), Runt-related transcription factor 2 (Runx-2), osteopontin (OPN), and osteocalcin (OCN). The results showed that h-ABMSCs were successfully cultured and revealed by microscopic observation. Human ABMSCs were spindle-shaped, with clustered and fish-like primary cells. Cell surface markers were negative for CD34 and positive for CD44 and CD90. PDLLA had no cytotoxicity. Human ABMSCs proliferated normally, and osteogenic differentiation of the cells was observed on the surface of PDLLA. Cellular proliferative activity and expression levels of osteogenesis-related genes of PDLLA and control groups showed no significant difference, including ALP, Runx-2, OPN, and OCN. These results suggest that 3D-printed PDLLA has good cell compatibility and biological activity.

Four-Dimensional Printing and Shape Memory Materials in Bone Tissue Engineering

The repair of severe bone defects is still a formidable clinical challenge, requiring the implantation of bone grafts or bone substitute materials. The development of three-dimensional (3D) bioprinting has received considerable attention in bone tissue engineering over the past decade. However, 3D printing has a limitation. It only takes into account the original form of the printed scaffold, which is inanimate and static, and is not suitable for dynamic organisms. With the emergence of stimuli-responsive materials, four-dimensional (4D) printing has become the next-generation solution for biological tissue engineering. It combines the concept of time with three-dimensional printing. Over time, 4D-printed scaffolds change their appearance or function in response to environmental stimuli (physical, chemical, and biological). In conclusion, 4D printing is the change of the fourth dimension (time) in 3D printing, which provides unprecedented potential for bone tissue repair. In this review, we will discuss the latest research on shape memory materials and 4D printing in bone tissue repair.

The Metabolic Changes between Monolayer (2D) and Three-Dimensional (3D) Culture Conditions in Human Mesenchymal Stem/Stromal Cells Derived from Adipose Tissue

INTRODUCTION

One of the key factors that may influence the therapeutic potential of mesenchymal stem/stromal cells (MSCs) is their metabolism. The switch between mitochondrial respiration and glycolysis can be affected by many factors, including the oxygen concentration and the spatial form of culture. This study compared the metabolic features of adipose-derived mesenchymal stem/stromal cells (ASCs) and dedifferentiated fat cells (DFATs) cultivated as monolayer or spheroid culture under 5% O₂ concentration (physiological normoxia) and their impact on MSCs therapeutic abilities.

RESULTS

We observed that the cells cultured as spheroids had a slightly lower viability and a reduced proliferation rate but a higher expression of the stemness-related transcriptional factors compared to the cells cultured in monolayer. The three-dimensional culture form increased mtDNA content, oxygen consumption rate (OCR) and extracellular acidification rate (ECAR), especially in DFATs-3D population. The DFATs spheroids also demonstrated increased levels of Complex V proteins and higher rates of ATP production. Moreover, increased reactive oxygen species and lower intracellular lactic acid levels were also found in 3D culture.

CONCLUSION

Our results may suggest that metabolic reconfiguration accompanies the transition from 2D to 3D culture and the processes of both mitochondrial respiration and glycolysis become more active. Intensified metabolism might be associated with the increased demand for energy, which is needed to maintain the expression of pluripotency genes and stemness state.

Dual Biosignal-Functional Injectable Microspheres for Remodeling Osteogenic Microenvironment

Bone defect regeneration depends on the population and lifespan of M2 macrophages, which are regulated by dual signals generated by the "physical" spatial configuration of biological tissues and "molecular" chemokines. Herein, inspired by the reprogramming of macrophages, immunoengineered porous microspheres are constructed to accelerate bone repair through the regulation of both "physical" and "molecular" signals. The porous structure of injectable poly (l-lactic acid) (PLLA) microspheres prepared by the microfluidic technique provides a "physical signal" for osteogenic differentiation. Additionally, interleukin (IL)-4-loaded liposomes (Ls) are modified on PLLA microspheres through amide bonds to produce IL-4/Ls/PLLA microspheres, providing a "molecular signal" in stimulating the differentiation of macrophages to M2 type. It is confirmed that IL-4/Ls/PLLA microspheres could induce M2-macrophages polarization and potentiate osteoblast proliferation and differentiation while coculturing with macrophages and osteoblasts in vitro. Besides, IL-4/Ls/PLLA microspheres are proved to promote bone defect regeneration by inducing the conversion of M1 macrophages to M2 through dual biosignal-functional regulation in both the calvaria defect and maxillary sinus defect models. Overall, the immuno-reprogrammed IL-4/Ls/PLLA microspheres achieve the precise immuno-reprogramming of macrophages by dual biosignal-functional regulation. This immune reengineering strategy paves a way for clinical bone defect treatment.

Clumps of mesenchymal stem cells/extracellular matrix complexes directly reconstruct the functional periodontal tissue in a rat periodontal defect model

Periodontitis is an inflammatory disease characterized by tooth-supporting periodontal tissue destruction, including the cementum, periodontal ligament, and alveolar bone. To regenerate the damaged periodontal tissue, mesenchymal stem cells (MSCs) have attracted much scientific and medical attention. Recently, we generated clumps of MSCs/extracellular matrix (ECM) complexes (C-MSCs), which consist of cells and self-produced ECM. C-MSCs can be transplanted into lesion areas without artificial scaffold to induce tissue regeneration. To develop reliable scaffold-free periodontal tissue regenerative cell therapy by C-MSCs, this study investigated the periodontal tissue regenerative capacity of C-MSCs and the behavior of the transplanted cells. Rat bone marrow-derived MSCs were isolated from rat femur. Confluent cells were scratched using a micropipette tip and then torn off. The sheet was rolled to make a three-dimensional round clump of cells, C-MSCs. Then, ten C-MSCs were grafted into a rat periodontal fenestration defect model. To trace the grafted cells in the defect, PKH26-labeled cells were also employed. Micro-CT and histological analyses demonstrated that transplantation of C-MSCs induced successful periodontal tissue regeneration in the rat periodontal defect model. Interestingly, the majority of the cells in the reconstructed tissue, including cementum, periodontal ligaments, and alveolar bone, were PKH26 positive donor cells, suggesting the direct tissue formation by MSCs. This study demonstrates a promising scaffold-free MSCs transplantation strategy for periodontal disease using C-MSCs and offers the significance of multipotency of MSCs to induce successful periodontal tissue regeneration.

Mesenchymal Stem/Stromal Cells and Their Paracrine Activity-Immunomodulation Mechanisms and How to Influence the Therapeutic Potential

With high clinical interest to be applied in regenerative medicine, Mesenchymal Stem/Stromal Cells have been widely studied due to their multipotency, wide distribution, and relative ease of isolation and expansion in vitro. Their remarkable biological characteristics and high immunomodulatory influence have opened doors to the application of MSCs in many clinical settings. The therapeutic influence of these cells and the interaction with the immune system seems to occur both directly and through a paracrine route, with the production and secretion of soluble factors and extracellular vesicles. The complex mechanisms through which this influence takes place is not fully understood, but several functional manipulation techniques, such as cell engineering, priming, and preconditioning, have been developed. In this review, the knowledge about the immunoregulatory and immunomodulatory capacity of MSCs and their secretion products is revisited, with a special focus on the phenomena of migration and homing, direct cell action and paracrine activity. The techniques for homing improvement, cell modulation and conditioning prior to the application of paracrine factors were also explored. Finally, multiple assays where different approaches were applied with varying success were used as examples to justify their exploration.

Fabrication and characterization of osteogenic function of progenitor cell-laden gelatin microcarriers

Biomaterial-based bone regeneration strategies often include a cellular component to accelerate healing. Modular approaches have the potential for minimally-invasive delivery and the ability to conformally fill complex defects. In this study, spherical gelatin microparticles were fabricated via water-in-oil emulsification and were subsequently crosslinked with genipin. Microparticle diameter depended on impeller geometry, and increased stirring rates consistently produced smaller particles with narrower size distributions. Increasing the concentration of gelatin resulted in larger particles with a broader size distribution. Viscoelastic characterization showed that increased gelatin concentration produced stiffer matrices, though the mechanical properties at lower gelatin concentration were more stable across strain rate. Microparticles of 6.0% wt/vol gelatin were then applied as microcarriers for packed-bed culture of human mesenchymal stromal cells (MSC) at seeding densities of 5.0 × 10³ , 2.5 × 10⁴ , or 5.0 × 10⁴ cells/cm² of surface area, in either control or osteogenic medium. Cell viability was uniformly high (>90%) across seeding densities over 22 days in culture. MSC number stayed approximately constant in the 5.0 × 10³ and 2.5 × 10⁴  cells/cm² samples, while it dropped over time at 5.0 × 10⁴ cells/cm² . Alkaline phosphatase activity was significantly upregulated in osteogenic conditions relative to controls at day 15, and absolute calcium deposition was strongly induced by days 15 and 22. However, calcium deposition per cell was highest in the lowest cell density, suggesting an inhibitory effect of high cell numbers. These results show that genipin-crosslinked gelatin microcarriers can be reproducibly fabricated and used as microcarriers for progenitor cells, which may have utility in treating large and complex bone defects.

3D Cocultures of Osteoblasts and Staphylococcus aureus on Biomimetic Bone Scaffolds as a Tool to Investigate the Host-Pathogen Interface in Osteomyelitis

Osteomyelitis (OM) is an infectious disease of the bone primarily caused by the opportunistic pathogen Staphylococcus aureus (SA). This Gram-positive bacterium has evolved a number of strategies to evade the immune response and subvert bone homeostasis, yet the underlying mechanisms remain poorly understood. OM has been modeled in vitro to challenge pathogenetic hypotheses in controlled conditions, thus providing guidance and support to animal experimentation. In this regard, traditional 2D models of OM inherently lack the spatial complexity of bone architecture. Three-dimensional models of the disease overcome this limitation; however, they poorly reproduce composition and texture of the natural bone. Here, we developed a new 3D model of OM based on cocultures of SA and murine osteoblastic MC3T3-E1 cells on magnesium-doped hydroxyapatite/collagen I (MgHA/Col) scaffolds that closely recapitulate the bone extracellular matrix. In this model, matrix-dependent effects were observed in proliferation, gene transcription, protein expression, and cell–matrix interactions both of the osteoblastic cell line and of bacterium. Additionally, these had distinct metabolic and gene expression profiles, compared to conventional 2D settings, when grown on MgHA/Col scaffolds in separate monocultures. Our study points to MgHA/Col scaffolds as biocompatible and bioactive matrices and provides a novel and close-to-physiology tool to address the pathogenetic mechanisms of OM at the host–pathogen interface.

Photoencapsulated-BMP2 in visible light-cured thiol-acrylate hydrogels for craniofacial bone tissue engineering

Aim: The study aimed to examine the impact of crosslinking BMP2 in biodegradable visible light-cured thiol-acrylate hydrogels. Materials & methods: BMP2 was photoencapsulated in 10 wt% PEG-diacrylate hydrogels with or without immortalized mouse bone marrow stromal cells (BMSC). Results & conclusion: Photoencapsulated-BMSC with BMP2 (BMBMP2) showed a significantly (p < 0.05) increased level in metabolic activity, by 54.61%, compared with photoencapsulated-BMSC at day 3. Furthermore, BMBMP2 groups showed significantly increased levels in ALP activity compared with BMSC at days, 1, 3, 7 (p < 0.01) and 10 (p < 0.05). This study shows promising results photoencapsulating BMP2 in thiol-acrylate hydrogels for craniofacial bone tissue engineering applications.

New Bioink Derived from Neonatal Chicken Bone Marrow Cells and Its 3D-Bioprinted Niche for Osteogenic Stimulators

This study examined whether neonatal chicken bone marrow cells (cBMCs) could support the osteogenesis of human stromal cells in a three-dimensional (3D) extracellular bioprinting niche. The majority (>95%) of 4-day-old cBMCs subcultured 5 times were positive for osteochondrogenesis-related genes (Col I, Col II, Col X, aggrecan, Sox9, osterix, Bmp2, osteocalcin, Runx2, and osteopontin) and their related proteins (Sox9, collagen type I, and collagen type II). LC-MS/MS analysis demonstrated that cBMC-conditioned medium (c-medium) contained proteins related to bone regeneration, such as periostin and members of the TGF-β family. Next, a significant increase in osteogenesis was detected in three human adipose tissue-derived stromal cell (hASC) lines, after exposure to c-medium concentrates in 2D culture (p < 0.05). To evaluate biological function in a 3D environment, we employed the cBMC-derived bioactive components as a cell-supporting biomaterial in collagen bioink, which was printed to construct a 3D hASC-laden scaffold for observing osteogenesis. Complete osteogenesis was detected in vitro. Moreover, after transplantation of the hASC-laden structure into rats, prominent bone formation was observed compared with that in control rats receiving scaffold-free hASC transplantation. These results demonstrated that substance(s) secreted by chick bone marrow cells clearly activated the osteogenesis of hASCs in 2D- or 3D-niches.

A Novel Plasma-Based Bioink Stimulates Cell Proliferation and Differentiation in Bioprinted, Mineralized Constructs

Extrusion-based bioprinting, also known as 3D bioplotting, is a powerful tool for the fabrication of tissue equivalents with spatially defined cell distribution. Even though considerable progress has been made in recent years, there is still a lack of bioinks which enable a tissue-like cell response and are plottable at the same time with good shape fidelity. Herein, we report on the development of a bioink which includes fresh frozen plasma from full human blood and thus a donor/patient-specific protein mixture. By blending of the plasma with 3 w/v% alginate and 9 w/v% methylcellulose, a pasty bioink (plasma-alg-mc) was achieved, which could be plotted with high accuracy and furthermore allowed bioplotted mesenchymal stromal cells (MSC) and primary osteoprogenitor cells to spread within the bioink. In a second step, the novel plasma-based bioink was combined with a plottable self-setting calcium phosphate cement (CPC) to fabricate bone-like tissue constructs. The CPC/plasma-alg-mc biphasic constructs revealed open porosity over the entire time of cell culture (35 d), which is crucial for bone tissue engineered grafts. The biphasic structures could be plotted in volumetric and clinically relevant dimensions and complex shapes could be also generated, as demonstrated for a scaphoid bone model. The plasma bioink potentiated that bioplotted MSC were not harmed by the setting process of the CPC. Latest after 7 days, MSC migrated from the hydrogel to the CPC surface, where they proliferated to 20-fold of the initial cell number covering the entire plotted constructs with a dense cell layer. For bioplotted and osteogenically stimulated osteoprogenitor cells, a significantly increased alkaline phosphatase activity was observed in CPC/plasma-alg-mc constructs in comparison to plasma-free controls. In conclusion, the novel plasma-alg-mc bioink is a promising new ink for several forms of bioprinted tissue equivalents and especially gainful for the combination with CPC for enhanced, biofabricated bone-like constructs.

Effects of miR-26a on Osteogenic Differentiation of Bone Marrow Mesenchymal Stem Cells by a Mesoporous Silica Nanoparticle - PEI - Peptide System

INTRODUCTION

RNA-based therapy for bone repair and regeneration is a highly safe and effective approach, which has been extensively investigated in recent years. However, the molecular stability of RNA agents still remains insufficient for clinical application. High porosity, tunable size, and ideal biodegradability and biosafety are a few of the characters of mesoporous silicon nanoparticles (MSNs) that render them a promising biomaterial carrier for RNA treatment.

MATERIALS AND METHODS

In this study, a novel miR-26a delivery system was constructed based on MSNs. Next, we assessed the miRNA protection of the delivery vehicles. Then, rat bone marrow mesenchymal stem cells (rBMSCs) were incubated with the vectors, and the transfection efficiency, cellular uptake, and effects on cell viability and osteogenic differentiation were evaluated.

RESULTS

The results demonstrated that the vectors protected miR-26a from degradation in vitro and delivered it into the cytoplasm. A relatively low concentration of the delivery systems significantly increased osteogenic differentiation of rBMSCs.

CONCLUSION

The vectors constructed in our study provide new methods and strategies for the delivery of microRNAs in bone tissue engineering.

Differences in osteogenic induction of human mesenchymal stem cells between a tailored 3D hybrid scaffold and a 2D standard culture

Many medical-related scientific discoveries arise from trial-error patterns where the processes involved must be refined and modified continuously before any product could be able to reach the final costumers. One of the elements affecting negatively these processes is the inaccuracy of two-dimension (2D) standard culture systems, carried over in plastic plates or similar, in replicating complex environments and patterns. Consequently, animal tests are required to validate every in vitro finding, at the expenses of more funds and ethical issues. A possible solution relies in the implementation of three-dimension (3D) culture systems as a fitting gear between the 2D tests and in vivo tests, aiming to reduce the negative in vivo outcomes. These 3D structures are depending from the comprehension of the extracellular matrix (ECM) and the ability to replicate it in vitro. In this article a comparison of efficacies between these two culture systems was taken as subject, human mesenchymal stem cells (hMSCs) was utilized and a hybrid scaffold made by a blend of chitosan, gelatin and biomineralized gelatin was used for the 3D culture system.

Sphingosine 1-Phosphate (S1P)/ S1P Receptor Signaling and Mechanotransduction: Implications for Intrinsic Tissue Repair/Regeneration

Tissue damage, irrespective from the underlying etiology, destroys tissue structure and, eventually, function. In attempt to achieve a morpho-functional recover of the damaged tissue, reparative/regenerative processes start in those tissues endowed with regenerative potential, mainly mediated by activated resident stem cells. These cells reside in a specialized niche that includes different components, cells and surrounding extracellular matrix (ECM), which, reciprocally interacting with stem cells, direct their cell behavior. Evidence suggests that ECM stiffness represents an instructive signal for the activation of stem cells sensing it by various mechanosensors, able to transduce mechanical cues into gene/protein expression responses. The actin cytoskeleton network dynamic acts as key mechanotransducer of ECM signal. The identification of signaling pathways influencing stem cell mechanobiology may offer therapeutic perspectives in the regenerative medicine field. Sphingosine 1-phosphate (S1P)/S1P receptor (S1PR) signaling, acting as modulator of ECM, ECM-cytoskeleton linking proteins and cytoskeleton dynamics appears a promising candidate. This review focuses on the current knowledge on the contribution of S1P/S1PR signaling in the control of mechanotransduction in stem/progenitor cells. The potential contribution of S1P/S1PR signaling in the mechanobiology of skeletal muscle stem cells will be argued based on the intriguing findings on S1P/S1PR action in this mechanically dynamic tissue.

Adipose-Derived Stem Cells in Bone Tissue Engineering: Useful Tools with New Applications

Adipose stem cells (ASCs) are a crucial element in bone tissue engineering (BTE). They are easy to harvest and isolate, and they are available in significative quantities, thus offering a feasible and valid alternative to other sources of mesenchymal stem cells (MSCs), like bone marrow. Together with an advantageous proliferative and differentiative profile, they also offer a high paracrine activity through the secretion of several bioactive molecules (such as growth factors and miRNAs) via a sustained exosomal release which can exert efficient conditioning on the surrounding microenvironment. BTE relies on three key elements: (1) scaffold, (2) osteoprogenitor cells, and (3) bioactive factors. These elements have been thoroughly investigated over the years. The use of ASCs has offered significative new advancements in the efficacy of each of these elements. Notably, the phenotypic study of ASCs allowed discovering cell subpopulations, which have enhanced osteogenic and vasculogenic capacity. ASCs favored a better vascularization and integration of the scaffolds, while improvements in scaffolds' materials and design tried to exploit the osteogenic features of ASCs, thus reducing the need for external bioactive factors. At the same time, ASCs proved to be an incredible source of bioactive, proosteogenic factors that are released through their abundant exosome secretion. ASC exosomes can exert significant paracrine effects in the surroundings, even in the absence of the primary cells. These paracrine signals recruit progenitor cells from the host tissues and enhance regeneration. In this review, we will focus on the recent discoveries which have involved the use of ASCs in BTE. In particular, we are going to analyze the different ASCs' subpopulations, the interaction between ASCs and scaffolds, and the bioactive factors which are secreted by ASCs or can induce their osteogenic commitment. All these advancements are ultimately intended for a faster translational and clinical application of BTE.

Enhancing survival, engraftment, and osteogenic potential of mesenchymal stem cells

Mesenchymal stem cells (MSCs) are promising candidates for bone regeneration therapies due to their plasticity and easiness of sourcing. MSC-based treatments are generally considered a safe procedure, however, the long-term results obtained up to now are far from satisfactory. The main causes of these therapeutic limitations are inefficient homing, engraftment, and osteogenic differentiation. Many studies have proposed modifications to improve MSC engraftment and osteogenic differentiation of the transplanted cells. Several strategies are aimed to improve cell resistance to the hostile microenvironment found in the recipient tissue and increase cell survival after transplantation. These strategies could range from a simple modification of the culture conditions, known as cell-preconditioning, to the genetic modification of the cells to avoid cellular senescence. Many efforts have also been done in order to enhance the osteogenic potential of the transplanted cells and induce bone formation, mainly by the use of bioactive or biomimetic scaffolds, although alternative approaches will also be discussed. This review aims to summarize several of the most recent approaches, providing an up-to-date view of the main developments in MSC-based regenerative techniques.

Clumps of Mesenchymal Stem Cell/Extracellular Matrix Complexes Generated with Xeno-Free Conditions Facilitate Bone Regeneration via Direct and Indirect Osteogenesis

Three-dimensional clumps of mesenchymal stem cell (MSC)/extracellular matrix (ECM) complexes (C-MSCs) consist of cells and self-produced ECM. We demonstrated previously that C-MSCs can be transplanted into bone defect regions with no artificial scaffold to induce bone regeneration. To apply C-MSCs in a clinical setting as a reliable bone regenerative therapy, the present study aimed to generate C-MSCs in xeno-free/serum-free conditions that can exert successful bone regenerative properties and to monitor interactions between grafted cells and host cells during bone healing processes. Human bone marrow-derived MSCs were cultured in xeno-free/serum-free medium. To obtain C-MSCs, confluent cells that had formed on the cellular sheet were scratched using a micropipette tip and then torn off. The sheet was rolled to make a round clump of cells. Then, C-MSCs were transplanted into an immunodeficient mouse calvarial defect model. Transplantation of C-MSCs induced bone regeneration in a time-dependent manner. Immunofluorescence staining showed that both donor human cells and host mice cells contributed to bone reconstruction. Decellularized C-MSCs implantation failed to induce bone regeneration, even though the host mice cells can infiltrate into the defect area. These findings suggested that C-MSCs generated in xeno-free/serum-free conditions can induce bone regeneration via direct and indirect osteogenesis.