Hydrogen Production by Ethanol Reforming on Supported Ni-Cu Catalysts.

Supported bimetallic Ni-Cu catalysts with different Ni-Cu loadings on alumina (Al2O3), alumina-silica (Al2O3-SiO2), alumina-magnesia (Al2O3-MgO), alumina-zinc oxide (Al2O3-ZnO), and alumina-lanthanum oxide (Al2O3-La2O3) were prepared and tested in ethanol steam reforming for the production of hydrogen (H2). These catalysts were characterized by X-ray diffraction, H2-temperature-programmed reduction, ammonia-temperature-programmed desorption, X-ray photoelectron spectroscopy, thermogravimetry, and differential scanning calorimetry. Cu addition improved the reducibility of NiO. Among the as-prepared catalysts, 30Ni5Cu/Al2O3-MgO and 30Ni5Cu/Al2O3-ZnO demonstrated much higher H2 selectivity and excellent coke resistance compared to the other investigated catalysts. Over 30Ni5Cu/Al2O3-MgO and 30Ni5Cu/Al2O3-ZnO, the respective H2 selectivity was 73.3 and 63.6% at 450 °C and increased to 94.0 and 95.2% at 600 °C. The strong interaction of Ni-Cu and Al2O3-ZnO (or Al2O3-MgO) led to the formation of smaller and highly dispersed CuO and NiO species on the carrier, which is conducive to improved catalytic performance. These Al2O3-MgO- and Al2O3-ZnO-supported bimetallic Ni-Cu materials can be promising catalysts for hydrogen production from ethanol steam reforming.

Biodegradable nanofibrous temperature-responsive gelling microspheres for heart regeneration.

Myocardial infarction (heart attack) is the number one killer of heart patients. Existing treatments for heart attack do not address the underlying problem of cardiomyocyte (CM) loss and cannot regenerate the myocardium. Introducing exogenous cardiac cells is required for heart regeneration due to the lack of resident progenitor cells and very limited proliferative potential of adult CMs. Poor retention of transplanted cells is the critical bottleneck of heart regeneration. Here, we report the invention of a poly(l-lactic acid)-b-poly(ethylene glycol)-b-poly(N-Isopropylacrylamide) copolymer and its self-assembly into nanofibrous gelling microspheres (NF-GMS). The NF-GMS undergo thermally responsive transition to form not only a 3D hydrogel after injection in vivo, but also exhibit architectural and structural characteristics mimicking the native extracellular matrix (ECM) of nanofibrous proteins and gelling proteoglycans or polysaccharides. By integrating the ECM-mimicking features, injectable form, and the capability of maintaining 3D geometry after injection, the transplantation of hESC-derived CMs carried by NF-GMS led to a striking 10-fold graft size increase over direct CM injection in an infarcted rat model, which is the highest reported engraftment to date. Furthermore, NF-GMS carried CM transplantation dramatically reduced infarct size, enhanced integration of transplanted CMs, stimulated vascularization in the infarct zone, and led to a substantial recovery of cardiac function. The NF-GMS may also serve as advanced injectable and integrative biomaterials for cell/biomolecule delivery in a variety of biomedical applications.

Suppressing mesenchymal stem cell hypertrophy and endochondral ossification in 3D cartilage regeneration with nanofibrous poly(l-lactic acid) scaffold and matrilin-3.

Articular cartilage has a very limited ability to self-heal after injury or degeneration due to its low cellularity, poor proliferative activity, and avascular nature. Current clinical options are able to alleviate patient suffering, but cannot sufficiently regenerate the lost tissue. Biomimetic scaffolds that recapitulate the important features of the extracellular matrix (ECM) of cartilage are hypothesized to be advantageous in supporting cell growth, chondrogenic differentiation, and integration of regenerated cartilage with native cartilage, ultimately restoring the injured tissue to its normal function. It remains a challenge to support and maintain articular cartilage regenerated by bone marrow-derived mesenchymal stem cells (BMSCs), which are prone to hypertrophy and endochondral ossification after implantation in vivo. In the present work, a nanofibrous poly(l-lactic acid) (NF PLLA) scaffold developed by our group was utilized because of the desired highly porous structure, high interconnectivity, and collagen-like NF architecture to support rabbit BMSCs for articular cartilage regeneration. We further hypothesized that matrilin-3 (MATN3), a non-collagenous, cartilage-specific ECM protein, would enhance the microenvironment of the NF PLLA scaffold for cartilage regeneration and maintain the cartilage property. To test this hypothesis, we seeded BMSCs on the NF PLLA scaffold with or without MATN3. We found that MATN3 suppresses hypertrophy in this 3D culture system in vitro. Subcutaneous implantation of the chondrogenic cell/scaffold constructs in a nude mouse model showed that pretreatment with MATN3 was able to maintain chondrogenesis and prevent hypertrophy and endochondral ossification in vivo. These results demonstrate that the porous NF PLLA scaffold treated with MATN3 represents an advantageous 3D microenvironment for cartilage regeneration and phenotype maintenance, and is a promising strategy for articular cartilage repair. STATEMENT OF SIGNIFICANCE: Articular cartilage defects, caused by trauma, inflammation, or joint instability, may ultimately lead to debilitating pain and disability. Bone marrow-derived mesenchymal stem cells (BMSCs) are an attractive cell source for articular cartilage tissue engineering. However, chondrogenic induction of BMSCs is often accompanied by undesired hypertrophy, which can lead to calcification and ultimately damage the cartilage. Therefore, a therapy to prevent hypertrophy and endochondral ossification is of paramount importance to adequately regenerate articular cartilage. We hypothesized that MATN3 (a non-collagenous ECM protein expressed exclusively in cartilage) may improve regeneration of articular cartilage with BMSCs by maintaining chondrogenesis and preventing hypertrophic transition in an ECM mimicking nanofibrous scaffold. Our results showed that the administration of MATN3 to the cell/nanofibrous scaffold constructs favorably maintained chondrogenesis and prevented hypertrophy/endochondral ossification in the chondrogenic constructs in vitro and in vivo. The combination of nanofibrous PLLA scaffolds and MATN3 treatment provides a very promising strategy to generate chondrogenic grafts with phenotypic stability for articular cartilage repair.

Porous nanofibrous poly(L-lactic acid) scaffolds supporting cardiovascular progenitor cells for cardiac tissue engineering.

Myocardial infarction (MI) is the irreversible necrosis of heart with approximately 1.5 million cases every year in the United States. Tissue engineering offers a promising strategy for cardiac repair after MI. However, the optimal cell source for heart tissue regeneration and the ideal scaffolds to support cell survival, differentiation, and integration, remain to be developed. To address these issues, we developed the technology to induce cardiovascular progenitor cells (CPCs) derived from mouse embryonic stem cells (ESCs) towards desired cardiomyocytes as well as smooth muscle cells and endothelial cells. We fabricated extracellular matrix (ECM)-mimicking nanofibrous poly(l-lactic acid) (PLLA) scaffolds with porous structure of high interconnection for cardiac tissue formation. The CPCs were seeded into the scaffolds to engineer cardiac constructs in vitro. Fluorescence staining and RT-PCR assay showed that the scaffolds facilitated cell attachment, extension, and differentiation. Subcutaneous implantation of the cell/scaffold constructs in a nude mouse model showed that the scaffolds favorably supported survival of the grafted cells and their commitment to the three desired lineages in vivo. Thus, our study suggested that the porous nanofibrous PLLA scaffolds support cardiac tissue formation from CPCs. The integration of CPCs with the nanofibrous PLLA scaffolds represents a promising tissue engineering strategy for cardiac repair. STATEMENT OF SIGNIFICANCE: Myocardial infarction is the irreversible necrosis of heart with approximately 1.5 million cases every year in the United States. Tissue engineering offers a promising strategy for cardiac repair after MI. However, the optimal cell source for heart tissue regeneration and the ideal scaffolds to support cell survival, differentiation, and integration, remain to be developed. To address these issues, we developed porous nanofibrous PLLA scaffolds that mimic natural extracellular matrix to support cardiac tissue formation from CPCs. The integration of CPCs with the nanofibrous PLLA scaffolds represents a promising tissue engineering strategy for cardiac repair.

Heart Regeneration with Embryonic Cardiac Progenitor Cells and Cardiac Tissue Engineering.

Myocardial infarction (MI) is the leading cause of death worldwide. Recent advances in stem cell research hold great potential for heart tissue regeneration through stem cell-based therapy. While multiple cell types have been transplanted into MI heart in preclinical studies or clinical trials, reduction of scar tissue and restoration of cardiac function have been modest. Several challenges hamper the development and application of stem cell-based therapy for heart regeneration. Application of cardiac progenitor cells (CPCs) and cardiac tissue engineering for cell therapy has shown great promise to repair damaged heart tissue. This review presents an overview of the current applications of embryonic CPCs and the development of cardiac tissue engineering in regeneration of functional cardiac tissue and reduction of side effects for heart regeneration. We aim to highlight the benefits of the cell therapy by application of CPCs and cardiac tissue engineering during heart regeneration.

Annulus fibrosus cell characteristics are a potential source of intervertebral disc pathogenesis.

In the end stage of intervertebral disc degeneration, cartilage, bone, endothelial cells, and neurons appear in association with the worsening condition. The origin of the abnormal cells is not clear. This study investigated the properties of progenitor cells in the annulus fibrosus (AF) using one in vitro and two in vivo models. Cultivation of rabbit AF cells with chondrogenic media significantly increased expressions of collagen and aggrecan. Upon exposure to osteogenic conditions, the cultures showed increased mineralization and expression of osteopontin, runx2, and bmp2 genes. Two models were used in the in vivo subcutaneous implantation experiments: 1) rabbit AF tissue in a demineralized bone matrix (DBM) cylinder (DBM/AF), and, 2) rat intact and needle punctured lumbar discs. Bone formation in the AF tissue was detected and hypertrophic chondrocytes and osteoblasts were present 1 month after implantation of the DBM/AF to nude mice. In addition to collagen I and II, immunostaining shows collagen X and osteocalcin expression in DBM/AF specimens 4 months after implantation. Similar changes were detected in the injured discs. Almost the entire needle punctured disc had ossified at 6 months. The results suggest that AF cells have characteristics of progenitor cells and, under appropriate stimuli, are capable of differentiating into chondrocytes and osteoblasts in vitro as well as in vivo. Importantly, these cells may be a target for biological treatment of disc degeneration.

The applications of buckminsterfullerene C60 and derivatives in orthopaedic research.

Abstract Buckminsterfullerene C60 and derivatives have been extensively explored in biomedical research due to their unique structure and unparalleled physicochemical properties. C60 is characterized as a "free radical sponge" with an anti-oxidant efficacy several hundred-fold higher than conventional anti-oxidants. Also, the C60 core has a strong electron-attracting ability and numerous functional compounds with widely different properties can be added to this fullerene cage. This review focused on the applications of C60 and derivatives in orthopaedic research, such as the treatment of cartilage degeneration, bone destruction, intervertebral disc degeneration (IVDD), vertebral bone marrow disorder, radiculopathy, etc., as well as their toxicity in vitro and in vivo. We suggest that C60 and derivatives, especially the C60 cores coupled with functional groups presenting new biological and pharmacological activities, are advantageous in orthopaedic research and will be promising in clinical performance for musculoskeletal disorders treatment; however, the pharmacokinetics and toxicology of these agents as local/systemic administration need to be carefully determined.

Fullerol nanoparticles suppress inflammatory response and adipogenesis of vertebral bone marrow stromal cells--a potential novel treatment for intervertebral disc degeneration.

BACKGROUND CONTEXT: Intervertebral disc degeneration, leading to chronic back pain, is a major health problem in western societies. Vertebral bone marrow has been considered to play an important role in nutrition supply and metabolic exchange for discs. Vertebral bone marrow lesions, including fatty marrow replacement and inflammatory edema, noted on magnetic resonance imaging were first described in 1988. PURPOSE: To investigate the potential of a free radical scavenger, fullerol nanoparticles, to prevent vertebral bone marrow lesion and prevent disc degeneration by inhibiting inflammation and adipogenic differentiation of vertebral bone marrow stromal cells (vBMSCs). STUDY DESIGN/SETTING: Fullerol nanoparticle solutions were prepared to test their in vitro suppression effects on mouse vBMSC inflammation and adipogenic differentiation compared with non-fullerol-treated groups. METHODS: With or without fullerol treatment, vBMSCs from Swiss Webster mice were incubated with 10 ng/mL interleukin-1 ß (IL-1 ß). The intracellular reactive oxygen species (ROS) were measured with fluorescence staining and flow cytometry. In addition, vBMSCs were cultured with adipogenic medium (AM) with or without fullerol. Gene and protein expressions were evaluated by real-time polymerase chain reaction and histologic methods. RESULTS: Fluorescence staining and flow cytometry results showed that IL-1 ß markedly increased intracellular ROS level, which could be prevented by fullerol administration. Fullerol also decreased the basal ROS level to 77%. Cellular production of matrix metalloproteinase (MMP)-1, 3, and 13 and tumor necrosis factor alpha (TNF-α) induced by IL-1 ß was suppressed by fullerol treatment. Furthermore, adipogenic differentiation of the vBMSCs was retarded markedly by fullerol as revealed by less lipid droplets in the fullerol treatment group compared with the adipogenic group. The expression of adipogenic genes PPARγ and aP2 was highly elevated with AM but decreased on fullerol administration. CONCLUSIONS: These results suggest that fullerol prevents the catabolic activity of vBMSCs under inflammatory stimulus by decreasing the level of ROS, MMPs, and TNF-α. Also, fat formation in vBMSCs is prevented by fullerol nanoparticles, and, therefore, fullerol may warrant further in vivo investigation as an effective biological therapy for disc degeneration.

Novel treatment of neuroinflammation against low back pain by soluble fullerol nanoparticles.

STUDY DESIGN: An in vitro study to investigate the anti-inflammatory effects of fullerol on mouse dorsal root ganglia (DRG) under tumor necrosis factor (TNF)-α induction. OBJECTIVE: To evaluate the potential of a free radical scavenger, fullerol nanoparticles, to prevent DRG tissue and neuron inflammatory responses under TNF-α induction in vitro. SUMMARY OF BACKGROUND DATA: Low back pain is one of the most common reasons for clinician visits in Western societies. Symptomatic intervertebral disc degeneration is strongly implicated as a cause of low back pain, as it results in DRG inflammation. Increased production of reactive oxygen species (ROS) is associated with DRG inflammation. METHODS: With or without fullerol treatment, DRG tissue and DRG neurons isolated from wild-type C3H/HeNCrl (Charles River Laboratories, Wilmington, MA) mice were cultured under TNF-α induction. The amount of intracellular ROS was measured with H2DCFDA (Life Technologies Corporation, Grand Island, NY) fluorescence staining. Cellular apoptosis was detected via terminal deoxynucleotidyl transferase dUTP nick-end labeling assay. The expression of inflammatory as well as antioxidative enzyme genes in neurons was analyzed by real-time polymerase chain reaction. In addition, inflammatory cytokine expression in DRG tissue was determined by immunofluorescence staining and enzyme-linked immunosorbent assay. RESULTS: Fluorescence staining results indicated that TNF-α markedly increased the production of intracellular ROS and the number of apoptotic cells. Under fullerol treatment, cellular apoptosis was reduced along with concomitant suppression of ROS. The expression of inflammatory cytokines interleukin 1 ß, interleukin 6, cyclooxygenase-2, and prostaglandin E2, was also inhibited by fullerol in a dose-dependent manner. Furthermore, fullerol-treated cells exhibited upregulation of antioxidative enzyme genes superoxide dismutase 2 and catalase. CONCLUSION: The results obtained from this study clearly suggest that fullerol treatment suppresses the inflammatory responses of DRG and neurons, as well as cellular apoptosis by decreasing the level of ROS and potentially enhancing antioxidative enzyme gene expression. Therefore, fullerol has potential to serve as a novel therapeutic agent for low back pain treatment. LEVEL OF EVIDENCE: N/A.

[A pilot study of three dimensional printing of human bone marrow stem cells (hBMSCs)].

PURPOSE: To establish a three-dimensional biological printing technique of hBMSCs. METHODS: The hBMSCs were regularly isolated and cultured, and adjusted to the density of 1x10(6)/mL single cell suspension. Then these cells were labeled by PI fluorescence marker, and transferred by rapid prototype biological printer. Deposition spots were 300microm apart at X-axis, 500microm at Y-axis, 50microm at Z-axis, and then observed by laser confocal microscope. RESULTS: This technique could deposit cells with good spatial control. In three-dimensional layer, each "cell ink" drop contained 15-35 hBMSCs post-transfer, and achieved accurate distribution with spots distributed 300microm apart at x-axis, 500microm at y-axis and 50microm at Z-axis. CONCLUSIONS: This study indicates that hBMSCs can be effectively delivered by a rapid prototype printer with speed and accuracy. Application of three dimensional printing is of great importance in tissue engineering bone.

A small diameter elastic blood vessel wall prepared under pulsatile conditions from polyglycolic acid mesh and smooth muscle cells differentiated from adipose-derived stem cells.

Smooth muscle layer plays an important role in maintaining homeostasis of blood vessels, thus generating a functional smooth muscle layer is a prerequisite for successful construction of blood vessels via tissue-engineering approach. In this study, we investigated the feasibility of constructing an elastic vessel wall in small diameter (less than 6 mm) using smooth muscle cells (SMCs) differentiated from human adipose-derived stem cells (hASCs) under pulsatile stimulation in a bioreactor. With the induction of transforming growth factor-beta1 (TGF-beta1) and bone morphogenetic protein-4 (BMP4) in combination for 7 days, hASCs were found to acquire an SMC phenotype characterized by the expression of SMC-related markers including smooth muscle alpha actin (alpha-SMA), calponin, and smooth muscle myosin heavy chain (SM-MHC). The SMCs derived from hASCs were seeded in polyglycolic acid (PGA) unwoven mesh and the cell-scaffold complex were subjected to pulsatile stimulation in a bioreactor for 8 weeks. The vessel walls engineered under the dynamic stimulation for 8 weeks showed a dense and well-organized structure similar to that of native vessels. The differentiated hASCs with dynamic loading were found to maintain their SMC phenotype within 3-dimensional PGA scaffold with a high level of collagen deposition close to that of native ones. Vessels constructed in the static condition showed a loose histological structure with less expression of contractile proteins. More importantly, the engineered vessel under pulsatile stimulation exhibited significant improvement in biomechanical properties over that generated from static conditions. Our results demonstrated that hASCs can serve as a new cell source for SMCs in blood vessel engineering, and an elastic small-diameter vessel wall could be engineered by in vitro culture of SMC-differentiated hASCs on the PGA scaffold with matchable biomechanical strength to that of normal blood vessels under pulsatile stimulation.

Differentiation of adipose-derived stem cells into contractile smooth muscle cells induced by transforming growth factor-beta1 and bone morphogenetic protein-4.

Smooth muscle cells (SMCs) play an essential role in maintaining the structural and functional integrity of blood vessel and thus is a critical element for blood vessel construction via tissue engineering approach. Adipose-derived stem cells (ASCs) represent a reliable source of mesenchymal stem cells with multidifferentiation potential. In this study, the feasibility of differentiation of human ASCs (hASCs) into cells with phenotypic and functional properties of SMCs was explored. hASCs isolated from human lipoaspirate were expanded to passage 5 and then induced with administration of transforming growth factor-beta1 (TGF-beta1) and bone morphogenetic protein-4 (BMP4) either alone or in combination with culture medium. Expression of SMC-related markers including alpha-SM actin (alpha-SMA, SM22alpha, calponin, and SM myosin heavy chain) were detected by immunofluorescent staining, reverse transcription (RT)-polymerase chain reaction, and western blot analysis. It was found that only under the circumstance of a combined stimulation with TGF-beta1 and BMP4, both early and mid markers (alpha-SMA, SM22alpha, calponin) as well as a late marker (SM myosin heavy chain) of SMC differentiation were identified to similar levels as those in human umbilical artery SMCs. More importantly, these SM differentiated cells showed the function of contracting collagen matrix lattice when they were entrapped inside. The contractile function of differentiated hASCs was further enhanced by direct exposure to 60 mM KCl, consistent with what occurred in human umbilical artery SMCs. These results provide evidence that ASCs possess the potential to differentiate into contractile SM-like cells when stimulated by TGF-beta1 and BMP4 together. SMCs differentiated from hASCs may provide an abundant source as seed cells for blood vessel engineering.

[Preliminary study on biological printing of hBMSCs].

OBJECTIVE: To establish a two-dimensional biological printing technique of hBMSCs so as to control the cell transfer process and keep cell viability after printing. METHODS: Bone marrow (5 mL) was obtained from healthy volunteer. The hBMSCs were regularly subcultured to harvest cells at passage 2, which were adjusted to the single cell suspension at a density of 1 x 10(6)/mL. The experiment was divided into 3 groups: printing group 1 in which cells underwent propidium iodide (PI) fluorescent labeling, then were transferred by rapid prototype biological printer (interval in x-axis 300 microm, interval in y-axis 1500 microm), and laser scanning confocal microscope was applied to observe cell fluorescence; printing group 2 in which cells received no PI labeling and were cultured for 2 hours after transfer, Live/Dead viability Kit was adopted to detect cell viability and laser scanning confocal microscope was applied to observe cell fluorescence; half of the cells in printing group receiving no Live/Dead viability Kit detection were cultured for 7 days, then inverted microscope was used to observe cell morphology, routine culture was conducted after the adherence of cells, the growth condition of cells was observed dynamically; control group in which steps were the same as the printing group 2 except that cell suspension received no printing. RESULTS: Laser scanning confocal microscope observation on the cells in printing group 1 revealed the "cell ink droplets" were distributed regularly and evenly in the two-dimensional layer and each contained 15-35 cells, meeting the requirement of designing two-dimensional cell printing. The cells in printing group 2 went through cell viability test, laser scanning confocal microscope observation showed the fluorescence of cells 30 minutes after cell incubation. There was no significant difference between the control group and the printing groups in terms of cell viability. The printed cells presented normal adherence, good morphology and good growth state 7 days after routine culture. CONCLUSION: Biological printing technique can realize the oriented, quantificational and regular distribution of hBMSCs in the two-dimensional plane and lays the foundation for the construction of three-dimensional cell printing or even organ printing system.

The role of the extracellular signal-related kinase signaling pathway in osteogenic differentiation of human adipose-derived stem cells and in adipogenic transition initiated by dexamethasone.

Human adipose-derived stem cells (hASCs) offer great promise for bone tissue engineering because of their osteogenic differentiation potential. At molecular levels, this study investigated the contribution of one of the main members of mitogen-activated protein kinases (MAPKs), extracellular signal-related kinase (ERK), to hASC osteogenic differentiation and the regulation of ERK for the balance between osteogenesis and adipogenesis in hASCs in vitro. As analyzed using western blot, ERK activation in osteo-induced hASCs was initiated at day 7, peaked at day 10, and declined from day 14 to basal levels. As detected using histochemical and biochemical methods, alkaline phosphatase (ALP) activity in hASCs experienced a process similar to that of ERK activation. Inhibition of ERK activation by PD98059, a specific inhibitor of the ERK signaling pathway, blocked the osteogenic differentiation in a dose-dependent manner, as revealed by an ALP activity assay, extracellular calcium deposition detection, osteocalcin (OCN) secretion examination, and real-time polymerase chain reaction (PCR) analysis for expression of osteogenesis-relative genes: core binding factor alpha 1, collagen type I, ALP, and OCN. Blockage of ERK phosphorylation in osteo-induced hASCs by PD98059 supplemented with dexamethasone (Dex) led to adipogenic differentiation, as confirmed by Nile Red staining to detect intracellular lipid droplets and real-time PCR analysis for expression of adipogenesis-relative genes: peroxisome proliferator-activated receptor gamma 2 and fatty acid-binding protein. These findings indicated a potential mechanism for the function of ERK in hASC osteogenic differentiation, especially the regulation of ERK in association with Dex for the balance between osteogenesis and adipogenesis, pointing out the significance of ERK signaling pathway for ASCs as a promising cell source for bone tissue engineering.

A comparative study of proliferation and osteogenic differentiation of adipose-derived stem cells on akermanite and beta-TCP ceramics.

This study investigated the in vitro effects of akermanite, a new kind of Ca-, Mg-, Si-containing bioceramic, on the attachment, proliferation and osteogenic differentiation of human adipose-derived stem cells (hASCs). Parallel comparison of the cellular behaviors of hASCs on the akermanite was made with those on beta-tricalcium phosphate (beta-TCP). Scanning electron microscope (SEM) observation and fluorescent DiO labeling were carried out to reveal the attachment and growth of hASCs on the two ceramic surfaces, while the quantitative assay of cell proliferation with time was detected by DNA assay. Osteogenic differentiation of hASCs cultured on the akermanite and beta-TCP was assayed by ALP expression and osteocalcin (OCN) deposition, which was further confirmed by Real-time PCR analysis for markers of osteogenic differentiation. It was shown that hASCs attached and spread well on the akermanite as those on beta-TCP, and similar proliferation behaviors of hASCs were observed on the two ceramics. Both of them exhibited good compatibility to hASCs with only minor cytotoxicity as compared with the tissue culture plates. Interestingly, the osteogenic differentiation of hASCs could be enhanced on the akermanite compared with that on the beta-TCP when the culture time was extended to approximately 10 days. Thus, it can be ascertained that akermanite ceramics may serve as a potential scaffold for bone tissue engineering.