Attenuating Epithelial-to-Mesenchymal Transition in Cancer through Angiopoietin-Like 4 Inhibition in a 3D Tumor Microenvironment Model.

Epithelial-to-mesenchymal transition (EMT) plays a crucial role in metastatic cancer progression, and current research, which relies heavily on 2D monolayer cultures, falls short in recapitulating the complexity of a 3D tumor microenvironment. To address this limitation, a transcriptomic meta-analysis is conducted on diverse cancer types undergoing EMT in 2D and 3D cultures. It is found that mechanotransduction is elevated in 3D cultures and is further intensified during EMT, but not during 2D EMT. This analysis reveals a distinct 3D EMT gene signature, characterized by extracellular matrix remodeling coordinated by angiopoietin-like 4 (Angptl4) along with other canonical EMT regulators. Utilizing hydrogel-based 3D matrices with adjustable mechanical forces, 3D cancer cultures are established at varying physiological stiffness levels. A YAP:EGR-1 mediated up-regulation of Angptl4 expression is observed, accompanied by an upregulation of mesenchymal markers, at higher stiffness during cancer EMT. Suppression of Angptl4 using antisense oligonucleotides or anti-cAngptl4 antibodies leads to a dose-dependent abolishment of EMT-mediated chemoresistance and tumor self-organization in 3D, ultimately resulting in diminished metastatic potential and stunted growth of tumor xenografts. This unique programmable 3D cancer cultures simulate stiffness levels in the tumor microenvironment and unveil Angptl4 as a promising therapeutic target to inhibit EMT and impede cancer progression.

An Active Bio-Based Food Packaging Material of ZnO@Plant Polyphenols/Cellulose/Polyvinyl Alcohol: DESIGN, Characterization and Application.

Active packaging materials protect food from deterioration and extend its shelf life. In the quest to design intriguing packaging materials, biocomposite ZnO/plant polyphenols/cellulose/polyvinyl alcohol (ZnPCP) was prepared via simple hydrothermal and casting methods. The structure and morphology of the composite were fully analyzed using XRD, FTIR, SEM and XPS. The ZnO particles, plant polyphenols (PPL) and cellulose were found to be dispersed in PVA. All of these components share their unique functions with the composite's properties. This study shows that PPL in the composite not only improves the ZnO dispersivity in PVA as a crosslinker, but also enhances the water barrier of PVA. The ZnO, PPL and cellulose work together, enabling the biocomposite to perform as a good food packaging material with only a 1% dosage of the three components in PVA. The light shielding investigation showed that ZnPCP-10 can block almost 100% of both UV and visible light. The antibacterial activities were evaluated by Gram-negative Escherichia coli (E. coli) and Gram-positive staphylococcus aureus (S. aureus), with 4.4 and 6.3 mm inhibition zones, respectively, being achieved by ZnPCP-10. The enhanced performance and easy degradation enables the biocomposite ZnPCP to be a prospect material in the packaging industry.

Effect of sagittal split ramus osteotomy on morphologic parameters of temporomandibular joint in patients with mandibular prognathism.

The purpose of this study was to evaluate the change in three-dimensional morphology and clinical symptoms of temporomandibular joint (TMJ) in class III dentofacial deformity patients postoperatively for 6 months after sagittal split ramus osteotomy (SSRO).Seventeen patients with skeletal Class III malocclusion and 10 asymptomatic volunteers (classified as Control group) were recruited for the study and underwent cone-beam computed tomography scanning. The geometries of the maxilla and mandible were reconstructed using MIMICS (Materialise, Leuven, Belgium). The morphologic measurements of the patients' TMJs were done before surgery and at 6-month follow-up - named as Pre and Post groups, respectively.The joint spaces (medial joint space, superior joint space, lateral joint space, anterior joint space, and posterior joint space) of the Control group were significantly greater than those of the Pre and Post groups (P < .05), and SSRO did not significantly change the TMJ morphology parameters. Five patients were found to have preoperative temporomandibular disorder (TMD) symptoms, and 3 of them were relieved at 6 months after surgery. Postoperative TMD symptom was observed in 1 patient without preoperative TMD symptom.SSRO did not markedly alter the TMJ morphology of the patients with mandibular prognathism. The effects of SSRO on TMD symptoms should be related to the type of deformity.

A numerical coupling method for particle tracking in electromagnetic fields.

With the arrival of the information age, the electromagnetic energy in space increases constantly, resulting in the influence of electromagnetic waves on the charged aerosol particles in the environment which should be taken into account. Here, a numerical coupling method based on temporal and spatial scales is proposed to solve the difficulty in obtaining the trajectory of particles under the action of high-frequency electromagnetic waves. In the temporal scale, two constant forces with linear relationship are used to equilibrate the electromagnetic field forces under different conditions, however the above-mentioned equivalent method has the space limitation; in addition, on the spatial scale, the model with larger geometry should be divided into multiple basic modules spatially, the domain division method is adopted and due to the above method it can be used well in the basic module. Verified the correctness through the comparison of the results, and compared with the traditional method, the above method greatly reduces the computational complexity. Some interesting results were obtained by calculating the modulated waves with the above method, which indicate that special forms of electromagnetic waves will significantly affect the motion of particles.

Acrolein induces ribotoxic stress in human cancer cells regardless of p53 status.

Acrolein (Acr) cytotoxicity contributes to chemotherapeutic activity of cyclophosphamide via metabolism of the anticancer drug. Our previous studies have shown that Acr causes ribosomal DNA (rDNA) damages, thus shuts down ribosomal RNA (rRNA) synthesis and leads to ribosomal stress in human cancer cells. Ribosome senses stress in 28S rRNA and induces subsequent activation of mitogen-activated protein kinase (MAPK) pathway which triggers ribotoxic stress response (RSR). Here, we report that cells harboring p53 or not responds differently to Acr-induced RSR. Our results show that Acr induced rRNA cleavage via the activated caspases in cancer cells with wild type p53, but not in cells with deficient p53. Furthermore, MAPK pathways were activated by Acr in cancer cells regardless of p53 status. Acr induced apoptosis in cells with wild type p53, while it induced G2/M cell cycle arrest in cancer cells with deficient p53. In conclusion, the presence of functional p53 plays a significant role in the mechanisms of Acr-induced rRNA cleavage and cell fates. Our results enhance our understanding of the molecular mechanisms of Acr-mediated antitumor activity which helps develop better therapeutic strategies for killing cancer cells with different p53 status.

The influence of bilateral sagittal split ramus osteotomy on the stress distributions in the temporomandibular joints of the patients with facial asymmetry under symmetric occlusions.

The aim of this study is to compare the differences in the stress distributions in the temporomandibular joints (TMJs) of the patients with facial asymmetry before and after bilateral sagittal split ramus osteotomy (BSSRO) under the symmetric occlusions using the three-dimensional (3D) finite element method.Ten facial asymmetry patients (Preoperative group, age 24.6 ±â€Š4.8 years) and 10 asymptomatic subjects (Control group, age 26.8 ±â€Š4.9 years) were recruited. After the patients underwent BSSRO, they were further assigned as the Postoperative group. 3D geometries of the finite element models of the mandible, disc, maxilla, and teeth were reconstructed according to cone-beam computed tomography (CBCT) image data. Contact elements were used to simulate the interaction of the disc-condyle, disc-temporal bone, and upper-lower dentition. The muscle forces and boundary conditions corresponding to the central and anterior occlusions were applied on the models of the 3 groups. The finite element models were validated with experimental data showing the accuracy of the simulation results.The simulation predicted preoperative significant differences of stresses between non-deviated sides and deviated sides were disappeared after the surgery under the central and anterior occlusions (P < .05). Almost all stresses in the patient models had significantly decreased after BSSRO, leveling it to the stress values of the normal subjects. Moreover, the simulation results coincided with the clinical cases which showed that BSSRO had helped to release or remove the signs and symptoms of temporomandibular disorders (TMD).In conclusion, BSSRO could correct the asymmetric stress distributions of TMJs and decrease the magnitude of the stresses for the patients with facial asymmetry. Those decreases also associated with the recovery of TMD.

Acrolein induces mtDNA damages, mitochondrial fission and mitophagy in human lung cells.

Acrolein (Acr), a highly reactive unsaturated aldehyde, can cause various lung diseases including asthma, chronic obstructive pulmonary disease (COPD), and lung cancer. We have found that Acr can damage not only genomic DNA but also DNA repair proteins causing repair dysfunction and enhancing cells' mutational susceptibility. While these effects may account for Acr lung carcinogenicity, the mechanisms by which Acr induces lung diseases other than cancer are unclear. In this study, we found that Acr induces damages in mitochondrial DNA (mtDNA), inhibits mitochondrial bioenergetics, and alters mtDNA copy number in human lung epithelial cells and fibroblasts. Furthermore, Acr induces mitochondrial fission which is followed by autophagy/ mitophagy and Acr-induced DNA damages can trigger apoptosis. However, the autophagy/ mitophagy process does not change the level of Acr-induced mtDNA damages and apoptosis. We propose that Acr-induced mtDNA damages trigger loss of mtDNA via mitochondrial fission and mitophagy. These processes and mitochondria dysfunction induced by Acr are causes that lead to lung diseases.

Reductive amination derivatization for the quantification of garlic components by isotope dilution analysis.

In this work, we synthesized internal standards for four garlic organosulfur compounds (OSCs) by reductive amination with 13C, D2-formaldehyde, and developed an isotope dilution analysis method to quantitate these organosulfur components in garlic samples. Internal standards were synthesized for internal absolute quantification of S-allylcysteine (SAC), S-allylcysteine sulfoxide (alliin), S-methylcysteine (SMC), and S-ethylcysteine (SEC). We used a multiple reaction monitoring (MRM) to detect 13C, D2-formaldehyde-modified OSCs by ultrahigh-performance liquid phase chromatography coupled with tandem mass spectrometry (UHPLC-MS/MS) and obtained MS spectra showing different ratios of 13C, D2-formaldehyde-modified and H2-formaldehyde-modified compounds. The resulting labeled and unlabeled OSCs were exhibited correlation coefficient (R2) ranged from 0.9989 to 0.9994, respectively. The average recoveries for four OSCs at three concentration levels ranged from 89% to 105%. By 13C, D2-formaldehyde and sodium cyanoborohydride, the reductive amination-based method can be utilized to generate novel internal standard for isotope dilution and to extend the quantitative application.

Identification and in vitro pharmacological characterization of a novel and selective α7 nicotinic acetylcholine receptor agonist, Br-IQ17B.

AIM: Alpha7-nicotinic acetylcholine receptor (α7 nAChR) is a ligand-gated Ca(2+)-permeable ion channel implicated in cognition and neuropsychiatric disorders. Activation of α7 nAChR improves learning, memory, and sensory gating in animal models. To identify novel α7 nAChR agonists, we synthesized a series of small molecules and characterized a representative compound, Br-IQ17B, N-[(3R)-1-azabicyclo[2,2,2]oct-3-yl]-5-bromoindolizine-2-carboxamide, which specifically activates α7 nAChR. METHODS: Two-electrode voltage clamp (TEVC) recordings were primarily used for screening in Xenopus oocytes expressing human α7 nAChR. Assays, including radioisotope ligand binding, Western blots, whole-cell recordings of hippocampal culture neurons, and spontaneous IPSC recordings of brain slices, were also utilized to evaluate and confirm the specific activation of α7 nAChR by Br-IQ17B. RESULTS: Br-IQ17B potently activates α7 nAChR with an EC50 of 1.8±0.2 µmol/L. Br-IQ17B is selective over other subtypes such as α4ß2 and α3ß4, but it blocks 5-HT3A receptors. Br-IQ17B displaced binding of the α7 blocker [(3)H]-MLA to hippocampal crude membranes with a Ki of 14.9±3.2 nmol/L. In hippocampal neurons, Br-IQ17B evoked α7-like currents that were inhibited by MLA and enhanced in the presence of the α7 PAM PNU-120596. In brain slice recordings, Br-IQ17B enhanced GABAergic synaptic transmission in CA1 neurons. Mechanistically, Br-IQ17B increased ERK1/2 phosphorylation that was MLA-sensitive. CONCLUSION: We identified the novel, potent, and selective α7 agonist Br-IQ17B, which enhances synaptic transmission. Br-IQ17B may be a helpful tool to understand new aspects of α7 nAChR function, and it also has potential for being developed as therapy for schizophrenia and cognitive deficits.

Gas-phase reaction of CeVO5(+) cluster ions with C2H4: the reactivity of cluster bonded peroxides.

Cerium-vanadium oxide cluster cations CeVO5(+) were generated by laser ablation, mass-selected using a quadrupole mass filter, thermalized through collisions with helium atoms, and then reacted with ethene molecules in a linear ion trap reactor. The cluster reactions have been characterized by time-of-flight mass spectrometry and density functional theory calculations. The CeVO5(+) cluster has a closed-shell electronic structure and contains a peroxide (O2(2-)) unit. The cluster bonded O2(2-) species is reactive enough to oxidize a C2H4 molecule to generate C2H4O2 that can be an acetic acid molecule. Atomic oxygen radicals (O(-)˙), superoxide radicals (O2(-)˙), and peroxides are the three common reactive oxygen species. The reactivity of cluster bonded O(-)˙ and O2(-)˙ radicals has been widely studied while the O2(2-) species were generally thought to be much less reactive or inert toward small molecules under thermal collision conditions. This work is among the first to report the reactivity of the peroxide unit on transition metal oxide clusters with hydrocarbon molecules, to the best of our knowledge.

Gas-phase reaction of CeV2O7+ with C2H4: activation of C-C and C-H bonds.

The reactivity of metal oxide clusters toward hydrocarbon molecules can be changed, tuned, or controlled by doping. Cerium-doped vanadium cluster cations CeV2O7(+) are generated by laser ablation, mass-selected by a quadrupole mass filter, and then reacted with C2H4 in a linear ion trap reactor. The reaction is characterized by a reflectron time-of-flight mass spectrometer. Three types of reaction channels are observed: 1) single oxygen-atom transfer , 2) double oxygen-atom transfer , and 3) C=C bond cleavage. This study provides the first bimetallic oxide cluster ion, CeV2O7(+), which gives rise to C=C bond cleavage of ethene. Neither Ce(x)O(y)(±) nor V(x)O(y)(±) alone possess the necessary topological and electronic properties to bring about such a reaction.

Theoretical Studies on Pyrazolo[3,4-d]pyrimidine Derivatives as Potent Dual c-Src/Abl Inhibitors Using 3D-QSAR and Docking Approaches.

In recent years, the development of dual or multi-targeted inhibitors has captured extensive attention of research for treating of malignancies. In this paper, three-dimensional quantitative structure-activity relationship and docking studies were performed on 87 pyrazolo[3,4-d]pyrimidines as dual Src/Abl inhibitors. The appropriate binding orientations and conformations of these compounds interacting with both Src and Abl kinases were revealed by docking studies, and the established optimum CoMFA models yielded q(2) =0.856, R(2) =0.966 for Src and q(2) =0.869, R(2) =0.974 for Abl, and the best CoMSIA models gave q(2) =0.877, R(2) =0.979 for Src and q(2) =0.885, R(2) =0.982 for Abl. Systemic external validations further confirm the satisfactory predictive power of these models, producing R(2) pred values of 0.872 and 0.865 for Src, 0.876 and 0.867 for Abl, r(2) m values of 0.832 and 0.928 for Src, 0.838 and 0.904 for Abl, respectively. In addition, through a comparison between 3D-QSAR contour maps and docking results, it is revealed that the hydrophobic and electrostatic interactions of compounds play significant roles for the inhibitory activity against both Src and Abl kinases. Some structural factors influencing the activities of these compounds were discussed in detail. The key amino acids impacting the receptor-ligand interactions have been identified. These theoretical results can offer useful references for designing novel potential dual Src/Abl inhibitors.

Coordinated control of bone cutting for a CT-free navigation robotic system in total knee arthroplasty.

BACKGROUND: Robots are gradually becoming intelligent tools for surgeons in computer assisted orthopedic surgery. A hands-on robot combining CT-free navigation software and coordinated control has been designed for total knee arthroplasty. METHODS: The hands-on robot is under bilateral force control so that the robot not only follows the force commands from the operator but also shapes the reflected force back to the operator. The proposed coordinated control also defines three operating modes to fulfill intelligent bone cutting by tuning appropriate scaling to the admittance gains. RESULTS: Experimental results demonstrated assistive, resistant and emergent actions to meet various bone cutting conditions by the coordinated controller. CONCLUSIONS: The proposed coordinated controller enables the robot to perform bone cutting more safely, rapidly and accurately compared with being performed by manual bone saw. The intelligent bone cutting has been successfully verified by a cadaver test.

Reactivity of oxygen radical anions bound to scandia nanoparticles in the gas phase: C-H bond activation.

The activation of C-H bonds in alkanes is currently a hot research topic in chemistry. The atomic oxygen radical anion (O(-·)) is an important species in C-H activation. The mechanistic details of C-H activation by O(-·) radicals can be well understood by studying the reactions between O(-·) containing transition metal oxide clusters and alkanes. Here the reactivity of scandium oxide cluster anions toward n-butane was studied by using a high-resolution time-of-flight mass spectrometer coupled with a fast flow reactor. Hydrogen atom abstraction (HAA) from n-butane by (Sc2O3)(N)O(-) (N=1-18) clusters was observed. The reactivity of (Sc2O3)(N)O(-) (N=1-18) clusters is significantly sizedependent and the highest reactivity was observed for N=4 (Sc8O13(-)) and 12 (Sc24O37(-)). Larger (Sc2O3)(N)O(-) clusters generally have higher reactivity than the smaller ones. Density functional theory calculations were performed to interpret the reactivity of (Sc2O3)(N)O(-) (N=1-5) clusters, which were found to contain the O(-·) radicals as the active sites. The local charge environment around the O(-·) radicals was demonstrated to control the experimentally observed size-dependent reactivity. This work is among the first to report HAA reactivity of cluster anions with dimensions up to nanosize toward alkane molecules. The anionic O(-·) containing scandium oxide clusters are found to be more reactive than the corresponding cationic ones in the C-H bond activation.

Synthesis, characterization, and anticancer activity of ruthenium(II)-ß-carboline complex.

Four [Ru(tpy)(N-N)(L)] type complexes: [Ru(tpy)(bpy)(Nh)](2+) (Ru1, tpy = 2,2';6',2″-terpyridine, bpy = 2'2-bipyridine, Nh = Norharman), [Ru(tpy)(phen)(Nh)](2+) (Ru2, phen = 1,10-phenanthroline), [Ru(tpy)(dpa)(Nh)](2+) (Ru3, dpa = 2,2'-dipyridylamine) and [Ru(tpy)(dip)(Nh)](2+) (Ru4, dip = 4,7-diphenyl-1,10-phenanthroline) were presented as anticancer drugs. In vitro cytotoxicity assays indicated that these complexes showed anticancer activity against various cancer cells. Flow cytometry and signaling pathways analysis demonstrated that these complexes induced apoptosis via the mitochondrial pathway, as evidenced by the loss of mitochondrial membrane potential and the release of cytochrome c. The resulting accumulation of p53 proteins from phosphorylation at serine-15 and serine-392 was correlated with an increase in p21 and caspase activation. Taken together, these findings suggested that Ru1-Ru4 may contribute to the future development of improved chemotherapeutics against human cancers.

Reactivity of atomic oxygen radical anions bound to titania and zirconia nanoparticles in the gas phase: low-temperature oxidation of carbon monoxide.

Titanium and zirconium oxide cluster anions with dimensions up to nanosize are prepared by laser ablation and reacted with carbon monoxide in a fast low reactor. The cluster reactions are characterized by time-of-flight mass spectrometry and density functional theory calculations. The oxygen atom transfers from (TiO(2))(n)O(-) (n = 3-25) to CO and formations of (TiO(2))(n)(-) are observed, whereas the reactions of (ZrO(2))(n)O(-) (n = 3-25) with CO generate the CO addition products (ZrO(2))(n)OCO(-), which lose CO(2) upon the collisions (studied for n = 3-9) with a crossed helium beam. The computational study indicates that the (MO(2))(n)O(-) (M = Ti, Zr; n = 3-8) clusters are atomic radical anion (O(-)) bonded systems, and the energetics for CO oxidation by the O(-) radicals to form CO(2) is strongly dependent on the metals as well as the cluster size for the titanium system. Atomic oxygen radical anions are important reactive intermediates, while it is difficult to capture and characterize them for condensed phase systems. The reactivity pattern of the O(-)-bonded (TiO(2))(n)O(-) and (ZrO(2))(n)O(-) correlates very well with different behaviors of titania and zirconia supports in the low-temperature catalytic CO oxidation.

Targeting telomeric G-quadruplexes with the ruthenium(II) complexes [Ru(bpy)(2)(ptpn)](2+) and [Ru(phen)(2)(ptpn)](2+).

Two ruthenium(II) polypyridyl complexes, [Ru(bpy)(2)(ptpn)](2+) (1) (bpy = 2,2'-bipyridine, ptpn = 3-(1,10-phenanthroline-2-yl)-as-triazino[5,6-f]1,10-phenanthroline) and [Ru(phen)(2)(ptpn)](2+) (2) (phen = 1,10-phenanthroline), were synthesized and characterized. Crystal structure analysis shows that complex 1 has a large planar aromatic area and possesses the potential to fit the geometric structure of G-quadruplex. The interaction of the G-quadruplex DNA with Ru(ii) complexes was explored by means of circular dichroism (CD), fluorescence resonance energy transfer (FRET) melting assay, competitive FRET assay and polymerase chain reaction (PCR) stop assay. The results indicated that complexes 1 and 2 both have the ability to promote the formation and stabilization of the human telomeric d[(TTAGGG)(n)] (HTG22) quadruplex and exhibit high G-quadruplex DNA selectivity over duplex DNA. The telomere repeat amplification protocol (TRAP) assay and long-term proliferation experiments further demonstrate that the Ru(II) complexes are potent telomerase inhibitors and HeLa cell proliferation inhibitors.

Comparison of in vivo adipogenic capabilities of two different extracellular matrix microparticle scaffolds.

BACKGROUND: The extracellular matrix is an essential microenvironment for cell survival activity. The adipose tissue extract microparticle scaffolds from human adipose tissue and small intestine submucosa microparticle scaffolds from porcine jejunum were prepared. Their effects on the adipogenic capabilities of human adipose-derived stem cells were compared in vivo. METHODS: A combination of physical and chemical methods was used to decellularize human fat and porcine jejunum. Expression of CD molecules on the adipose-derived stem cell surface was determined by flow cytometry. The stem cells were then cultured with the scaffold materials in vitro. The cell-scaffold complexes were implanted subcutaneously into nude mice, and samples were collected 4 and 8 weeks later. The adipogenic differentiation capabilities of adipose-derived stem cells were studied by histologic methods and real-time polymerase chain reaction. RESULTS: The authors observed high expression of CD90 and CD44; no expression of CD34, CD45, CD31, or CD106; and weak positive expression of CD49d on the extracted cells, which indicates that the cells were adipose-derived stem cells. The main constituent of the decellularized adipose tissue extract and small intestine submucosa microparticles was collagenous fiber, and the cells proliferated faster on the adipose tissue extract than on small intestine submucosa. Formation of adipocytes in the adipose tissue extract group was closer to that of normal human fat tissue compared with that of the small intestine submucosa group. CONCLUSIONS: Extracellular matrix microparticle scaffolds could promote proliferation, adhesion, and adipogenic differentiation of adipose-derived stem cells. The role of the adipose tissue extract microparticle scaffold in promoting adipogenesis was stronger and more suitable as a vector in fatty tissue engineering.

[Construction of tissue engineering bone with bone marrow stromal cell sheets].

OBJECTIVE: To construct tissue engineering bone with bone marrow stromal cell (BMSC) sheets of dogs. METHODS: BMSC were derived from dog bone marrow and cell sheets were prepared with temperature-responsive dishes after the cells were induced by osteogenesis. Allogeneic dogs decalcification bone matrixes (DBM) were prepared. Sixteen dogs were divided into 4 groups. The MSC cell sheets-rhBMP-2-BMSC-DBM were implanted under the left latissimus dorsi myofascial as the experimental side; while the rhBMP-2-BMSC-DBM were implanted in the right side as the control. Ectopic bone formation in vivo was evaluated by histological examination 4, 8, 12, 16 weeks after operation. RESULTS: The osteogenesis in the experimental group was better than that in the control group. New bone area in the experimental side was larger than that in the control group, and the difference was significant (P < 0.05). After 16 weeks, lamellar bone was connected into a film in the experimental group. Haversian system and red bone marrow could be seen. CONCLUSIONS: BMSC cell sheets could promote the bone formation of functional tissue-engineered bone.

[Study of bone marrow stroma stem cells cell-sheet and endothelial progenitor cells cultured in vitro on allogenic demineralized bone matrix in mongrel].

PURPOSE: To investigate the growth situation of bone marrow stroma stem cells(BMSCs) cell-sheet and endothelial progenitor cells (EPCs) on demineralized bone matrix (DBM) and explore the effect of DBM/BMSCs cell-sheet and DBM/EPCs complex on the construction of functional and vascularized tissue-engineered bone in mongrel. METHODS: BMSC cell-sheet was prepared with cell-sheet engineering approach, EPCs were isolated from canine bone marrow and DBM was prepared from homologous bone. BMSCs cell-sheet and EPCs were inoculated on DBM respectively and observed by inverted phase contrast microscope and scanning electron microscope. The porosity of DBM was measured. RESULTS: The DBM/BMSCs cell-sheet and DBM/EPCs complex were successfully constructed. The BMSCs cell-sheet and EPCs adhered to DBM well and grew rapidly. CONCLUSIONS: The BMSCs cell-sheet and EPCs have good biocompatibility with DBM. The complex of DBM/ BMSCs cell-sheet, DBM/EPCs could provide good conditions to acquire functional and vascularized tissue-engineered bone. Supported by National Natural Science Foundation of China (Grant No.30872896) and Natural Science Foundation of Shandong Province (Grant No.Y2008C77).