Sprayable hydroxypropyl chitin/collagen extract of Ampelopsis brevipedunculata hydrogel accelerates wound healing.

OBJECTIVE: Keeping a wound moist can allow effective and rapid healing, and it can control the formation of scabs, thereby allowing cell proliferation and epithelial formation. When regularly changing a dressing, thermosensitive hydrogel as a moist dressing does not cause a secondary wound from adhesion. The main aim of this study was to evaluate the effect of a new sprayable thermosensitive hydrogel on wound healing. METHOD: The hydrophobic N-acetyl group of chitin was removed by microwave reaction with lye until the degree of acetylation was 60%, followed by reaction with propylene oxide to obtain hydroxypropyl chitin (HPCH) with a degree of substitution of 40%. After mixing HPCH with fish scale collagen (FSC), a thermosensitive hydrogel with a gel temperature of 26.5°C was obtained. Ampelopsis brevipedunculata extracts (ABE), which have been found to accelerate wound repair and improve healing, were added. HPCH/FSC is not toxic to the mouse L929 cell line and forms a hydrogel at body surface temperature. It can be easily sprayed on a wound. The HPCH/FSC has a three-dimensional network porous structure with a swelling ratio of 10.95:1 and a water vapour transmission rate of 2386.03±228.87g/m2/day; it can facilitate the penetration of water and air, and promote absorption of wound exudate. Wound repair was performed on five Sprague-Dawley rats. Each rat had three wounds, which were treated with medical gauze, HPCH/FSC and HPCH/FSC/ABE, respectively. RESULTS: The wounds in the HPCH/FSC/ABE group recovered the fastest in vivo, the mature wound site was smoother, the re-epithelialisation was even and thicker, and the angiogenesis developed rapidly to the mature stage. CONCLUSION: In this study, HPCH/FSC/ABE thermosensitive hydrogel was shown to effectively accelerate wound healing and was convenient for practical application.

Therapeutic Potential of Pretreatment with Exosomes Derived from Stem Cells from the Apical Papilla against Cisplatin-Induced Acute Kidney Injury.

Acute kidney injury (AKI) is the most serious side effect of treatment with cisplatin in clinical practice. The aim of this study was to investigate the therapeutic effect of exosomes derived from stem cells from the apical papilla (SCAPs) on AKI. The medium from a SCAP culture was collected after 2 d of culture. From this, SCAP-derived exosomes (SCAP-ex), which were round (diameter: 30-150 nm) and expressed the characteristic proteins CD63 and CD81, were collected via differential ultracentrifugation. Rat renal epithelial cells (NRK-52E) were pretreated with SCAP-ex for 30 min and subsequently treated with cisplatin to induce acute injury. The extent of oxidative stress, inflammation, and apoptosis were used to evaluate the therapeutic effect of SCAP-ex against cisplatin-induced nephrotoxicity. The viability assay showed that the survival of damaged cells increased from 65% to 89%. The levels of reactive oxygen species decreased from 176% to 123%. The glutathione content increased by 78%, whereas the levels of malondialdehyde and tumor necrosis factor alpha (TNF-α) decreased by 35% and 9%, respectively. These results showed that SCAP-ex can retard oxidative stimulation in damaged kidney cells. Quantitative reverse transcription-polymerase chain-reaction gene analysis showed that they can also reduce the expression of nuclear factor-κß (NF-κß), interleukin-1ß (IL-1ß), and p53 in AKI. Further, they increased the gene expression of antiapoptotic factor B-cell lymphoma-2 (Bcl-2), whereas they reduced that of proapoptotic factors Bcl-2-associated X (Bax) and caspase-8 (CASP8), CASP9, and CASP3, thereby reducing the risk of cell apoptosis.

Highly Organized Porous Gelatin-Based Scaffold by Microfluidic 3D-Foaming Technology and Dynamic Culture for Cartilage Tissue Engineering.

A gelatin-based hydrogel scaffold with highly uniform pore size and biocompatibility was fabricated for cartilage tissue engineering using microfluidic 3D-foaming technology. Mainly, bubbles with different diameters, such as 100 µm and 160 µm, were produced by introducing an optimized nitrogen gas and gelatin solution at an optimized flow rate, and N2/gelatin bubbles were formed. Furthermore, a cross-linking agent (1-ethyl-3-(3-dimethyl aminopropyl)-carbodiimide, EDC) was employed for the cross-linking reaction of the gelatin-based hydrogel scaffold with uniform bubbles, and then the interface between the close cells were broken by degassing. The pore uniformity of the gelatin-based hydrogel scaffolds was confirmed by use of a bright field microscope, conjugate focus microscope and scanning electron microscope. The in vitro degradation rate, mechanical properties, and swelling rate of gelatin-based hydrogel scaffolds with highly uniform pore size were studied. Rabbit knee cartilage was cultured, and its extracellular matrix content was analyzed. Histological analysis and immunofluorescence staining were employed to confirm the activity of the rabbit knee chondrocytes. The chondrocytes were seeded into the resulting 3D porous gelatin-based hydrogel scaffolds. The growth conditions of the chondrocyte culture on the resulting 3D porous gelatin-based hydrogel scaffolds were evaluated by MTT analysis, live/dead cell activity analysis, and extracellular matrix content analysis. Additionally, a dynamic culture of cartilage tissue was performed, and the expression of cartilage-specific proteins within the culture time was studied by immunofluorescence staining analysis. The gelatin-based hydrogel scaffold encouraged chondrocyte proliferation, promoting the expression of collagen type II, aggrecan, and sox9 while retaining the structural stability and durability of the cartilage after dynamic compression and promoting cartilage repair.

Biological and Cytoprotective Effect of Piper kadsura Ohwi against Hydrogen-Peroxide-Induced Oxidative Stress in Human SW1353 Cells.

Oxidative stress plays a role in regulating a variety of physiological functions in living organisms and in the pathogenesis of articular cartilage diseases. Piper kadsura Ohwi is a traditional Chinese medicine that is used as a treatment for rheumatic pain, and the extracts have anti-inflammatory and antioxidant effects. However, there is still no study related to cell protection by P. kadsura. The P. kadsura extracts (PKE) were obtained by microwave-assisted extraction, liquid-liquid extraction, and column chromatography separation. The extracts could effectively scavenge free radicals in the antioxidant test, the EC50 of extracts is approximately the same as vitamin C. PKE decreased the apoptosis of SW1353 cells treated with H2O2 and could upregulate the gene expression of antioxidant enzymes (SOD-2, GPx, and CAT) and the Bcl-2/Bax ratio, as well as regulate PARP, thus conferring resistance to H2O2 attack. PKE protects cells against apoptosis caused by free radicals through the three pathways of JNK, MEK/ERK, and p38 by treatment with MAPK inhibitor. The identified components of PKE were bicyclo [2.2.1] heptan-2-ol-1,7,7-trimethyl-,(1S-endo)-, alpha-humulene, and hydroxychavicol by gas chromatography-mass spectrometry.

Coaxial nanofibers encapsulated with Ampelopsis brevipedunculata extract and green synthesized AgNPs for wound repair.

Silver nanoparticles (AgNPs) synthesized from Aloe vera extract exhibited a pronounced antibacterial effect, while the Ampelopsis brevipedunculata extract (ABE) showcased a high antioxidant capacity for wound healing. Spherical AgNPs with a particle size of 28.82 nm crystallized in a face-centered-cubic lattice. AgNPs/polyvinyl alcohol (PVA) and ABE/polycaprolactone (PCL) underwent electrospinning to produce coaxial and electrosprayed nanofibers, respectively. The developed coaxial nanofibers demonstrated a strain of 159%, a Young's modulus of elasticity of 7080.14 kPa, a 3.9-fold swelling ratio, a water contact angle of 38.91°, characteristic hydrophilicity, and an adequate water vapor transmission rate of 2272 g/m2/day. ABE exhibited no cytotoxicity to L929 cells and induced a twofold increase in the cell migration rate. Upon applying the developed coaxial nanofiber on an in vivo rat model with a 9 mm wound diameter, the wound rapidly and completely healed within 10 days, with a healing speed 60% greater than that of the control group. Histopathological analysis revealed that the coaxial group did not exhibit inflammation, showed complete epithelization, and featured a well-arranged deposition of collagen on the 10th day.

Effects of Organic Elicitors on the Recycled Production of Ginkgolide B in Immobilized Cell Cultures of Ginkgo biloba.

Ginkgo biloba is a medicinal plant used in complementary and alternative medicines. Ginkgo biloba extracts contain many compounds with medical functions, of which the most critical is ginkgolide B (GB). The major role that GB plays is to function as an antagonist to the platelet-activating factor, which is one of the causes of thrombosis and cardiovascular diseases. Currently, GB is obtained mainly through extraction and purification from the leaves of Ginkgo biloba; however, the yield of GB is low. Alternatively, the immobilized cultivation of ginkgo calluses with biomaterial scaffolds and the addition of organic elicitors to activate the cell defense mechanisms were found to stimulate increases in GB production. The aim of this study was to use Ginkgo biloba calluses for immobilized cultures with different elicitors to find a more suitable method of ginkgolide B production via a recycling process.

Achyranthes bidentate extracts protect the IL-1ß-induced osteoarthritis of SW1353 chondrocytes.

Osteoarthritis, the most common joint disease worldwide, is a degenerative disease characterized by cartilage degeneration and inflammation. The active ingredients in the traditional Chinese medicinal plant Achyranthes bidentate can be used to treat waist, leg, and joint pain caused by rheumatism arthralgia. In this study, we identified the optimal microwave extraction protocol for saponins from A. bidentate, evaluated their protective effects against IL-1ß-induced inflammation in SW1353 human chondrocytes, and explored their protective pathway. The microwave-extraction parameters required to obtain the maximum yield of A. bidentate saponins using 80% ethanol were identified using response surface methodology. The parameters were solid-liquid ratio, 1:10; extraction time, 20 min; power, 721 W; temperature, 65 °C. The actual yield of saponins extracted was to be 194.01 µg/mg extract. The SW1353 cells were pretreated with A. bidentate extract (ABE) at a concentration of 50 or 100 µg/mL for 3 h, after which an inflammatory response was stimulated using IL-1ß. The ABE significantly reduced the expression of proinflammatory factors IL-6, TNF-α, COX-2, iNOS, PGE2, and NO, and inhibited NF-κB activity, effectively attenuating the inflammatory response. ABE also inhibited MMP13 and ADAMTS-5 expression, reducing IL-1ß-induced degradation of the extrachondral matrix. This confirmed that ABE effectively inhibits NF-κB activity and reduces IL-1ß-induced inflammation, extracellular matrix degradation, and expression of apoptotic proteins Bax and caspase-3. Therefore, ABE has potential as a new botanical drug for preventing osteoarthritis.

DOPA-mediated reduction allows the facile synthesis of fluorescent gold nanoclusters for use as sensing probes for ferric ions.

In this paper, we describe a simple one-pot method, employing l-3,4-dihydroxyphenylalanine (L-DOPA) as a reducing/capping reagent, for the synthesis of fluorescent gold nanoclusters (AuNCs). Within a short reaction time of 15 min (excluding the time required for purification), this strategy allows the fabrication of homogeneous AuNCs having the capability to sense ferric ions (Fe(3+)). The as-prepared AuNCs exhibited a fluorescence emission at 525 nm and a quantum yield of 1.7%. On the basis of an aggregation-induced fluorescence quenching mechanism, these fluorescent AuNCs offer acceptable sensitivity, high selectivity, and a limit of detection of 3.5 µM for the determination of Fe(3+) ions, which is lower than the maximum level (0.3 mg L(-1), equivalent to 5.4 µM) of Fe(3+) permitted in drinking water by the U.S. Environmental Protection Agency.

Heat-induced antigen retrieval applied in zebrafish: whole-mount in situ immunofluorescence microscopy.

Whole-mount immunofluorescence technique provides a way to reveal integrated expression patterns of biological molecules in individuals. Well-documented morphological preservation ability in biology makes aldehydes the fixative of choice. Cross-linking among biocomponents and aldehydes is the key for maintaining morphology but masks the biological molecules for immunodetection. This study performs an easily accessible method by applying heat-induced retrieval, which can rescue the antigenicity of the proteins and also enhance the labeling sensitivity of the fluorescence dye in overfixed zebrafish embryos. The results show that the immunoreactivities of antibodies to myosin in the muscles, green fluorescent protein in the blood vessels and the nuclei in the cells can be recovered significantly, and the morphology of the zebrafish embryos, even the fragile mutants, is at the same time well maintained. Therefore, we provide a choice for antigen retrieval, which is effective for whole-mount immunofluorescence microscopy.

Evaluation and Preparation of a Designed Kartogenin Drug Delivery System (DDS) of Hydrazone-Linkage-Based pH Responsive mPEG-Hz-b-PCL Nanomicelles for Treatment of Osteoarthritis.

Osteoarthritis (OA) is a chronic disease caused by the damage of articular cartilage. Kartogenin (KGN) is a well-recognized small molecule which could induce MSCs chondrogenesis and promote cartilage repair treatments. Nano-level micells could be a suitable drug carrier technology for the treatments. In this study, the acid-responsive methoxy poly(ethylene oxide)-hydrazone-poly(ε-caprolactone) copolymers, mPEG-Hz-b-PCL, were synthesized. The structure was characterized by 1H NMR. The evaluation of a designed kartogenin drug delivery system (DDS) of hydrazone-linkage-based pH responsive mPEG-Hz-b-PCL nanomicelles for treatment of osteoarthritis could be carried out.

Ex vivo expansion of a hematopoietic stem cell on a murine stromal cell by 3D micro-pillar device.

Stromal cells alter their mode of attachment, cellular shape, and protein expression when placed on square arrays of micro-pillars. All the pillars we studied had 50 µm diameters, 85 µm pillar heights, were separated by 50 µm, and had an identical surface chemistry. We found that these micro-pillars provided many opportunities for mechanical interlocking and were more suitable attachment matrixes for cell adhesion and stretching of the overlying biomaterials. When the feeder layer cells of hematopoietic stem cells (HSCs) were cultured into the micro-pillar device, they could screen more hematopoietic cytokines, such as interleukin-3 (IL-3), and laminin into the medium. Consequently, the micro-pillar device provides a greater degree of HSCs expansion relative to the 25 T flask. The maximal expansion of the HSCs and the colony-forming unit (CFU) on the micro-pillar device increased 62.72-fold and 16.95-fold for 28 day culture, but there were only 58.08-fold and 6.8-fold expansion on the 25 T flask. The results showed a significantly higher expansion in the pillar device compared to the 25 T flask; moreover, the stemness was maintained. Therefore, the 3D micro-pillar device appears to be a more suitable culture substrate for HSCs expansion ex vivo.

Polycaprolactone/Polyethylene Glycol Blended with Dipsacus asper Wall Extract Nanofibers Promote Osteogenic Differentiation of Periodontal Ligament Stem Cells.

Dipsacus asper wall (DA) is an ancient Chinese medicinal material that has long been used to maintain the health of human bones. The present study aimed to evaluate the osteogenic differentiation of periodontal ligament stem cells (PDLSCs) of Dipsacus asper wall extracts (DAE). Microwave-assisted alcohol extraction of 100 mesh DA powder under optimal conditions can obtain 58.66% (w/w) yield of the crude extract. PDLSCs have excellent differentiation potential. PDLSCs treated with DA extract (DAE) underwent osteogenesis, exhibiting a higher expression of the Col-1, ALP, Runx2, and OCN genes, and had a 1.4-fold increase in mineralization, demonstrating the potential of DAE to promote osteogenic differentiation. After the addition of PI3K inhibitor LY294002, the expression of osteogenic genes was significantly inhibited, confirming that PI3K is an important pathway for DAE to induce osteogenesis. Mix DAE with polycaprolactone/polyethylene glycol (PCL/PEO) to obtain nanofibers with a diameter of 488 nm under optimal electrospinning conditions. The physical property analysis of nanofibers with and without DAE includes FTIR, mechanical strength, biodegradability, swelling ratio and porosity, and cell compatibility. When cells induced by nanofibers with or without DAE, the mineralization of PDLSCs cultured on PCL/PEO/DAE was 2.6-fold higher than that of PCL/PEO. The results of the study confirm that both DAE and PCL/PEO nanofibers have the effect of promoting osteogenic differentiation. In order to obtain the best induction effect, the optimal amount of DAE can be discussed in future research.

Phosphorylation of levan by microwave-assisted synthesis enhanced anticancer ability.

Levan is an exopolysaccharide produced by Bacillus licheniformis (strain FRI MY-55) that shows promising pharmacological activity. Phosphorylation is a chemical modification that can increase the biological and antioxidant properties of levan. In this study, levan was phosphorylated by microwave-assisted synthesis to achieve a degree of substitution of 0.29. The hydroxyl radical scavenging activity of microwave-assisted phosphorylated levan (microwave P) increased significantly (6-fold) over native levan; this activity was only slightly lower than vitamin C. Other free radical scavenging and reducing power tests revealed that Microwave P activity was increased by 30-40%. Microwave P inhibited the proliferation of HCT-116 and A549 cancer cell lines more readily than native levan with an IC50 of 1.03 mg/mL and 1.38 mg/mL for HCT-116 and A549 cells, respectively. Cells treated with native levan and its derivatives remained in the sub-G1 phase according to cell cycle analysis, whereas Microwave P treatment increased the proportion of cells undergoing apoptosis. Furthermore, Microwave P effectively upregulated pro-apoptosis marker Bax and downregulated anti-apoptosis marker Bcl-2, in addition to inducing the expression of caspase-9 and caspase-3. These findings show that levan phosphorylated via microwave-assisted synthesis showed increased antioxidant and antitumor activity over native levan or levan phosphorylated via traditional long-term heating. In particular, Microwave P possesses antiproliferative activity and can induce apoptosis through mitochondrial pathways in cancerous cells.

Stem Cells from Human Exfoliated Deciduous Teeth: A Concise Review.

Stem Cells from Human Exfoliated Deciduous Teeth (SHED) originate from the embryonic neural crest as ectodermal mesenchymal stem cells and are isolated from human deciduous teeth. SHED expresses the same cell markers as Embryonic Stem Cells (ESCs), such as OCT4 and NANOG, which make SHED to have a significant impact on clinical applications. SHED possess higher rates of proliferation, higher telomerase activity, increased cell population doubling, form sphere-like clusters, and possess immature and multi-differentiation capacity; such high plasticity makes SHED one of the most popular sources of stem cells for biomedical engineering. In this review, we describe the isolation and banking method, the current development of SHED in regenerative medicine and tissue engineering in vitro and in vivo.

A study of the differentiation of stem cells from human exfoliated deciduous teeth on 3D silk fibroin scaffolds using static and dynamic culture paradigms.

Stem cells from human exfoliated deciduous teeth (SHED) are considered the best current source of human stem cells due to their ability to differentiate into multiple cell lineages. Dynamic co-culture systems can improve the culture environment, as they provide cells with signaling factors, extracellular matrixes, and cellular shear force, as well as enable the formation of heterotypic clusters. We seeded SHED in 3D silk fibroin porous scaffolds under static and dynamic cultures for 28 days, using the NIH3T3 cultivated medium as an induction agent. Many hepatospheres formed in these porous scaffolds, and cellular viability was shown to continually increase by MTT assays. Hepatic AFP and ALB gene expression, as well as glycogen storage, albumin secretion, and urea synthesis, were greater in cells in the 3D porous scaffold under a dynamic culture than in those cultured under 3D static culture and petri dish conditions. However, the 3D static culture is still superior to the traditional petri dish culture. The NIH3T3 cultivated medium can significantly induce hepatic differentiation of SHED, while the 3D dynamic culture system significantly enhances hepatic differentiation of SHED. This study provides alternative sources of hepatocytes for liver disease treatment.

Optimizing emulsan production of A. venetianus RAG-1 using response surface methodology.

Statistical experimental design was used to optimize medium constituents for emulsan production by Acinetobacter venetianus RAG-1 in batch cultivation. The factors affecting emulsan production were screened by a two-level factorial design, and the optimal concentration of medium constituents for emulsan production were determined by the method of steepest path ascent and central composite experimental design. Experimental results showed that the optimal medium constituents were 9.16 g/L ethanol, 8.2 g/L KH(2)PO(4), 23.32 g/L K(2)HPO(4), 5.77 g/L (NH(4))(2)SO(4) and 0.354 g/L MgSO(4)*7H(2)O. Under this optimal composition, the predicted emulsan production was 72.198 mg/L, and experimental value was 73.312 mg/L for 80 h culture in the shake flasks, and the emulsan yield by A. venetianus RAG-1 was enhanced nearly 1.48-fold (from 49.5 to 73.312 mg/L). Based on the results, we identify the optimal medium constituents for emulsan production and could take advantage of strategy for scale up the fermentation of emulsan production.

Epidermal cells differentiated from stem cells from human exfoliated deciduous teeth and seeded onto polyvinyl alcohol/silk fibroin nanofiber dressings accelerate wound repair.

Mesenchymal stem cells (MSCs) or epidermal stem cells (ESCs) may be used as a source of cells for skin wound repair in order to preserve the patient's remaining autologous skin and reduce the wound area and pain. Many studies use MSCs as therapeutic cells for wound healing, but treatment with ESCs instead can speed up wound repair. In additional to therapeutic cells, the biomechanical properties and surface topography of the dressing also affect the speed of wound healing. Silk fibroin (SF) has the property of promoting collagen regeneration to accelerate wound healing. It has made into nanofibers as a wound healing dressing with hydrophilic polyvinyl alcohol (PVA). Methanol-treated PVA-SF dressing (PFSM) is a beadless nanofiber that can mimic the structure of endogenous extracellular matrix. In this study, SHED was first differentiated into ESCs and then effects of SHED and ESCs on wound closure were compared. Differentiation of SHED into ESCs was shown to induce growth factors that reached a maximum on the third day. In vivo, PFSM/ESC showed regeneration of granulation tissue on the third day, and the wound closure percent was 53.49%, which was 1.18-fold higher than PFSM/SHED. Therefore, the differentiation of stem cells into ESCs in advance combined with PFSM dressing can effectively accelerate wound healing in vivo. These findings can be applied to clinical treatment in the future.

Comparing the Effects of Chitosan Scaffolds Containing Various Divalent Metal Phosphates on Osteogenic Differentiation of Stem Cells from Human Exfoliated Deciduous Teeth.

Inducing the differentiation of stem cells from human exfoliated deciduous teeth (SHEDs) proceeds with low efficiency, which greatly limits clinical applications. Divalent metal elements play an important role in osteoinductivity for bone remodeling because they can simulate bone formation and decrease bone resorption. The purpose of this study was to investigate the effect of some divalent metal phosphates on osteogenic differentiation from human exfoliated deciduous teeth. These divalent metal ions can be gradually released from the scaffold into the culture medium and continually induce osteoblastic differentiation. Experimental results revealed that SHEDs cultured in chitosan scaffolds containing divalent metal phosphates had notably increased osteoblastic differentiation compared with cells cultured without divalent metal phosphates. This effect was due to the high activity of alkaline phosphatase, as well as the bone-related gene expression of collagen type I, Runx2, osteopontin, osteocalcin, VEGF, and Ang-1, shown through RT-PCR and bone-related protein immunocytochemistry stains. A calcium-content assay further revealed significant enhancement of deposited minerals on the scaffolds after 21 days of culture, particularly for magnesium phosphate and zinc phosphate. Thus, divalent metals, except for barium phosphate, effectively promoted SHED cell differentiation and osteoblastic cell maturation. This study demonstrated that the divalent metal elements magnesium, strontium, and zinc could effectively induce SHED osteoblastic differentiation for use in tissue engineering and bone repair.

Magnesium and zinc borate enhance osteoblastic differentiation of stem cells from human exfoliated deciduous teeth in vitro.

Various biocompatible and biodegradable scaffolds blended with biochemical signal molecules with adequate osteoinductive and osteoconductive properties have attracted significant interest in hard tissue engineering regeneration. We evaluated the distinct effects of magnesium borate, zinc borate, and boric acid blended into chitosan scaffold for osteogenic differentiation of stem cells from exfoliated deciduous teeth. Stem cells from exfoliated deciduous teeth cells are a potential source of functional osteoblasts for applications in bone tissue engineering, but the efficiency of osteoblastic differentiation is low, thereby significantly limiting their clinical applications. Divalent metal borates have potential function in bone remodeling because they can simulate bone formation and decrease bone resorption. These magnesium, zinc, and B ions can gradually be released into the culture medium from the scaffold and induce advanced osteoblastic differentiation from stem cells from exfoliated deciduous teeth. Stem cells from exfoliated deciduous teeth with magnesium borate or zinc borate as inducer demonstrated more osteoblastic differentiation after 21 days of culture. Differentiated cells exhibited activity of alkaline phosphatase, bone-related gene expression of collagen type I, runt-related transcription factor 2, osteopontin, osteocalcin, vascular endothelial growth factor, and angiopoietin-1, as noted via real-time polymerase chain reaction analysis, as well as significant deposits of calcium minerals. Divalent mental magnesium and zinc and nonmetal boron can be an effective inducer of osteogenesis for stem cells from exfoliated deciduous teeth. This experiment might provide useful inducers for osteoblastic differentiation of stem cells from exfoliated deciduous teeth for tissue engineering and bone repair.

Observation of fibroblast motility on a micro-grooved hydrophobic elastomer substrate with different geometric characteristics.

We used a hydrophobic micro-textured poly-dimethylsiloxane (PDMS) in the presence of serum protein at 37 degrees C to study the motility of mouse stromal fibroblast on variant (15-100microm) parallel ridge/groove with 30microm depth. In this paper, we observed the temporal changes in cell morphology and locomotion by using time-lapse phase-contrast microscopy. When fibroblasts seeded onto the micro-grooved substrate, almost all of cells concentrated at the bottom of the grooves. Sequentially, the fibroblasts attached and spread on the surface, migrated toward the walls of the grooves, climbed up and down the ridges frequently, apparently, the 30microm depth of groove did not hinder movement across the micro-grooves. Eventually, they stopped proliferating as a result of contact inhibition and formed a confluent monolayer on the ridges almost exclusively, with an orientation parallel to the direction of the ridge/groove. Cellular shape of fibroblast was enhanced with the micro-grooves, the form index of nucleus was 2.6-fold greater than that of cells on smooth surfaces. Further, we found that hydrophobic surfaces are more prone to direct cellular motility in comparison with hydrophilic surfaces.