Earticle

Mercuric compounds are very toxic. There are many reports indicating its genotoxic potential in a variety of organisms including humans and aquatic species [1]. Inorganic mercury occurs in numerous forms. The most common include mercuric chloride (HgCl2) and mercurous chloride (Hg2Cl2). Mercuric chloride adversely affects the central and peripheral nervous system, the kidney, the eye and reproductive fitness [2]. Meanwhile, earthworms can be used as a bio-indicator of contamination in soil [3]. This study was performed to investigate the acute toxic effects of mercuric chloride in earthworm, Eisenia fetida. The earthworms were exposed to 0 ~ 160 mg/kg of mercuric chloride in the soil for 24 and 48 hours. Then DNA damage and repair was measured with the comet assay from 0 to 72 hours after HgCl2 treatment. The level of DNA damage in the earthworms was shown as the olive tail moment. The DNA tail moment is defined that both the length of tail and the intensity of the DNA in the tail. The results showed that the higher the concentration of mercury was treated, the greater damage and the longer repair time were expressed. This study confirmed that the comet assay applied on earthworm’ coelomocytes may be a useful tool in determining the potential genotoxicity of soil pollutants.

Monooxygenases show effective biocatalytic activities that produce enantioselective products utilizing oxygen as an oxidant. Especially, flavin-cofactor-dependent styrene monooxygenase is widely studied. This enzyme converts styrene to (s)-styrene oxide using FADH2 as a cofactor. (s)-styrene oxide is a important chiral intermediate for the production of pharmaceuticals and some fine chemicals1-2. This enzyme composes of two parts: ‘tyA’for the production of (s)-styrene oxide and ‘tyB’for the regeneration of the flavin cofactor FAD from nicotinamide cofactor NADH. In general, however, this two-enzyme-based (s)-styrene oxide synthesis system has some problems. The most serious one is that it consumes expensive nicotinamide cofactor constantly to regenerate the flavin cofactor. To overcome this drawback, herein, we applied light-driven flavin cofactor regeneration system instead of applying styB enzyme. We could regenerate flavin cofactor by using xanthene dyes which can mediate electron transfer to the flavin cofactor FAD to FADH2 from the visible light without nicotinamide cofactor. Through this strategy, we could simplify the process to synthesize (s)-styrene oxide to get enough cost-effectiveness. Moreover, we compared the effect of various xanthene dyes on conversion and turnover rate of the enzymatic reactions.

Recently, Biomass has become one of the most fascinating subjects and is an extremely important alternative for energy source ever since the deficiency of fossil fuels. VFA(Volatile Fatty Acid) platform, being one of many methods applied from biomass, can synthesize mixed alcohol to use VFAs. There are two pathways to synthesize mixed alcohols by employing VFAs. The first pathway is a direct reaction with hydrogen; the other is to use esterification and hydrogenolysis respectively. The latter method is recognized to be far more economical and efficient. For hydrogenolysis, catalyst is an important factor, and Cu-based catalyst usually plays the role in this reaction and we use Cu-based catalyst. In this study, by knowing the best reaction condition (temperature, pressure), a high yield mixed alcohol is achievable.

Docosahexaenoic acid (DHA) is a key omega-3 polyunsaturated fatty acid (PUFA) that is beneficial to human health. DHA is a major structural component of the gray matter of brain and eye retina and an important component of heart tissue. As a result, dietary DHA has been shown to play an important role in proper development of the brain and in eye of infants and in cardiovascular health. A number of algal groups, including diatoms, crysophytes, cryptophytes, dinoflagellates and others, have been reported to produce long chain PUFAs including DHA. DHA derived directly from microalgae grown in fermentation tank can avoid worries about oceanborne contaminants or toxins, which may be associated with fish-based DHA.Aurantiochytrium sp. is marine heterotrophic microalga containing DHA rich lipid. Heterotrophs can be an alternative to autotrophs which have problems with low maximum biomass densities. In this study, Aurantiochytrium sp. will be cultivated in a fermentation tank using a medium with glucose or other utilizable carbon source. DHA can be produced from microalgae by extracting lipid with high content of DHA. Total lipid with high content of DHA will be extracted from Aurantiochytrium sp. after applying cell disintegration techniques which include enzyme digestion, ultrasonication, osmotic shock and so on. The DHA content of microalgae will be determined by gas chromatography (GC) analysis of the total lipid extract. Residual microalgal biomass remained after lipid extraction will be reused as a biosorbent to remove heavy metals from aqueous solution. Heavy metals can be eliminated by making interactions with functional groups on residual biomass surface.

2,3-butanediol (2,3-BD) is a very useful chemical, which is used as a solvent, a liquid fuel, and a precursor of many synthetic polymers. A 2,3-BD-producing bacterium, which was identified as Raoultella sp. B6, was isolated from an oil-contaminated soil sample. The isolate could produce 2,3-BD using various carbon sources. The effects of initial glucose concentration, initial pH, and temperature on 2,3-butanediol production were investigated using flask test. These parameters influenced the productivity and yield of 2,3-BD, and the production of the other fermentation products such as succinate, lactate, acetate, formic acid, acetic acid, and ethanol. The final 2,3-BD concentration was proportional to the initial glucose concentration. However, the productivity is inversely related to the initial glucose concentration. The growth rate and 2,3-BD production was the highest at neutral pH. The bacterium produced 2,3-BD at the start of the cell growth at 30 ℃, whereas it produced 2,3-BD in the middle of exponential phase at 25℃. Nevertheless, the highest concentration of 2,3-BD was the same in both cases. Based on these results, fed-batch culture was performed with or without aeration. This experiment showed that aeration has a positive effect on the cell growth and 2,3-BD production.

Recently, biomass is regarded as one of important resources because that can be converted biofuels which is most interested issue in the field of biotechnology. M any biochemical processes have adapted saccharificated land plants and microorganism such as Clostridium tyrobutyricumto produce biofuels. In the process, most of the microorganism convert the lignocellulose hydrolysate to bioenergy (butyric acid) under strict anaerobic condition. The land plants contains about 26% lignin (phenolics) in general. However, lignin (phenolics) often inhibit the cell growth and consequently the productivity in the process. In this study, we isolated mutanted Clostridium tyrobutyricum that have tolerance to lignin by gamma-ray irradiation. These mutants exhibited the remarkably improved cell growth and the production of butyric acid to the level of the control.

The optimization of fermentation conditions for butanol production was investigated using Clostridium pasteurianum DSM525, which is known to produce almost exclusively acetate and butyrate when grown on glucose. when C. pasteurianum DSM 525 was grown on glycerol, it produced ethanol, butanol, and 1,3-propanediol(1,3-PD) as the major products, while the acid formation was decreased. The addition of glucose significantly influenced the cell growth and butanol production by C. pasteurianum DSM 525 in batch cultures. The progressive increase in glucose concentration in culture medium containing a given concentration of glycerol to a molar glucose/glycerol ratio of 3 enhanced cell growth and butanol production and decreased 1,3-PD production. Our results indicats that the ratio of glycerol and glucose is an important factor for butanol production by C. pasteurianum DSM 525. Further optimization experiments will be done using three variables (glycerol, glucose, (NH4)2SO4), which significantly influence butanol production by C. pasteurianum DSM 525, using respose surface methodology.

A 2,3-butanediol (2,3-BDO)-producing bacterium was isolated from a tidal flat soil sample. Analysis of the 16S rDNA sequence showed that the isolate was closely related to members of the species Klebsiella oxytoca. The major product of fermentation by the isolate was 2,3-BDO. The effect of initial glucose concentration, temperature, aerobic and anaerobic condition, and various saccharides on 2,3-BDO production were investigated. Optimumtemperature and substrate concentration for 48h fermentation were 30℃ and 40g glucose/L, respectively. The production of 2,3-BDO under aerobic condition (14.2g/L) was higher than under anaerobic condition (12.6g/L). The isolate used monosaccharides and polysaccharides as a source of carbon and energy. K.oxytoca M1 produced 2,3-BDO from glucose with the yield of 56g/100g glucose after 72h of grow that optimum condition. This yield of 2,3-BDO was higher than that for K.oxytoca KCTC1686 (44g/100gglucose).

Glycerol is a by-product of biodiesel production and ethanol fermentation. In this study, the production of butanol from glycerol by Clostridium pasteurianum DSM 525 was evaluated at various substrate concentrations, pHs, and temperatures. The all three factors influenced the growth rate and fermentation product profile. At the glycerol concentration more than 80 g/L, the growth rate and butanol yield were decreased significantly. At the pH values lower than 6.0 or higher than 7.0, the growth rate of C. pasteurianum DSM 525 was decreased significantly and the butanol yield was the highest at pH 6.0 (0.27 g butanol produced/g glycerol consumed). The growth rate was decreased as the temperature decreased from 37 to 25 oC, and butanol yield was lower at 25 oC (0.17) compared with higher temperatures. The butanol yields at 30 and 37 oC were similar (0.27 and 0.25, respectively), but glycerol consumption was lower at 37 oC than at 30 oC (56 and 68 g/L, respectively), and thus the final butanol concentration was higher at 30 oC than at 37 oC. At the optimal condition (pH 6.0, 30 oC and 80 g/L of glycerol), C. pasteurianum DSM 525 produced 18.3 g/L of butanol for 36 hour-incubation.

Recently, the chemical modification of biomasses has been extensively tried to enhance their sorption capacity. It has been reported that the amount or kind of functional groups is an important factor for enhancement of sorption capacity(1, 2, 3). In previous studies, the biosorption capacity can be enhanced by enhancing active site or removing inhibition site on the biomass(2, 3, 4). Along the same line, the presence of modified functional groups on the biomass surface can affect their buffering capacity. In present study, we try to obtain the relationship between the sorption performance and buffering capacity and therewith to predict the sorption performance of chemically modified biosorbents from the information of buffering capacity. As model biosorbents, poly(acrylic acid)-modified biomass (PAAB), poly ethylenimine-modified biomass (PEIB), decarboxylated biomass (DCB), deaminated biomass (DAB) and raw Corynebacterium glutamcum as biosorbents were used. FTIR, potentiometric titration, and XPS analysis were carried out for estimating functional groups on the surface of the biosorbents. The buffering capacity of each functional group was calculated from potentiometric titration results. To estimate the maximum sorption capability, Basic Blue 3 (BB3) and Reactive Red 4 (RR4) were used as a model solute. As a result, it was found that the enhancement of buffering capacities was closely related to that of sorption capacities. Therefore, maximum sorption capacity of modified biomass could be predicted from its buffering capacity which can be tested more easily.

Methyl-ethyl-ketone (MEK) is an important commercial chemical used as a low-boiling solvent. MEK has been produced by dehydrogenation of secondary butanol or direct oxidation of n-butene and hence is non-renewable. Herein, we showed that acetoacetate decarboxylase (AADC, E.C. 4.1.1.4) from Clostridium acetobutylicum can convert levulinic acid to MEK. AADC was successfully expressed in E.coli with high expression level, 2.89 mg/ml. Permeabilized whole cells of E.coli expressing AADC with 6xHis tag converted 8.8 % of levulinic acid to MEK while no MEK was detected from control cells lacking AADC. AADC with 6xHis tag was purified by nickel affinity chromatography and converted 26.1 % of levulinic acid to MEK. Kinetic parameters and stability of the enzyme was also determined.

In this study we are willing to recognize the effect of collagen scaffold contained with HA(Hyaluronic acid) for dental tissue engineering. The type I atelocollagen was mixed with 0%, 10%, 25% of HA. Then, the solutions were using to make collagen-HA sponge scaffolds. The diameter of scaffolds was 3cm. Scaffolds were crosslinked with 0.02% carbodiimide and lyophilized for 48 h. And they were sterilized by γ- irradiation at 10 KGy. DPSCs(dental pulp stem cells) were seeded into scaffolds at a density of 5x105 cells/scaffold and cultured for 3weeks in growth medium. Then, they were cultured for 4weeks in differentiation medium and were transplanted in the nude mouse. The biopsy was processed at 8weeks. Col I and fibronectin, osteocalcin, osteopontin, osteonectin, osteoprotegerin levels in the culture were greatest in the 10% of HA. The calcification and the revelation of ostecalcin, osteopontin, osteonectin, and osteoprotegerin were better made in the collagen-HA sponge scaffold contained with 10% of HA. We could make collagen sponge scaffold contained various concentration of HA. Among them, 10% of HA was the most effective for osteogenesis. It will be a suitable substrate as biomaterial for bone tissue.

Mesenchymal stem cells are multipotent cells capable of differentiating into various mesenchymal tissues, such as bone, cartilage, fat, tendon and muscle. In order to explore their usages in medical applications, the ex vivo expansion of MSCs to sufficient cell numbers is necessary. The expansion of MSCs strongly depends on the culture conditions like pH, temperature, oxygen, basal medium, serum and other supplements. In this study, a newly-formulated in-house medium introduced for effective culture of mesenchymal stem cells and culture environments such as pH, oxygen, carbon dioxide in gas phase have been investigated. The new in-house medium showed much better performances in cell expansion as well as differentiation potential of cultured cells when compared with commercial media including DMEM, KSFM, MSCGM and Mesencult. Carbon dioxide content in gas phase needs to be carefully considered particularly when the widely used DMEM is introduced as a basal medium, since there is strong possibility of increased pH value even in common carbon dioxide condition of 5%. Oxygen content in gas phase also has shown the influence in the culture of MSC.

Mass production is the key for successful use of embryonic stem cells(ESCs) in cell therapy. Analysis of cellular morphology is prerequite for assessing ESCs status since morphological change can be an index to a pattern of cellular behavior. ESCs normally grow in a colonial form when cultured attached on a plate. In this research, we investigated and mathematically analyzed cellular motilities of ESCs and finally suggested an analytical model indicating ESCs colonial propagation.

The combination of viral gene delivery and key features of biomaterial scaffolds that control viral delivery in a controlled manner greatly enable tissue engineering applications. In this study, adeno-associated virus (AAV), which have safety and efficient gene delivery capability in human gene therapy as therapeutic vectors, was encapsulated by electrospinning blended mixtures of elastin-like polypeptides (ELPs) and poly (e-caprolactone) (PCL) and was employed to transduce fibroblasts adhered on the scaffolds. Combinatorial interactions between ELP and PCL chains with varying ratios significantly altered wettability, elastic modulus and strain of the ELP/PCL composites. Then this system was useful tools to mediate controlled release of AAV vectors and efficient cellular transduction on the fibrous scaffolds. The capacity of ELP/PCL composites to modulate the controlled release of AAV-mediated gene delivery for subsequent high-efficiency cellular transduction will provide tremendous opportunities for a variety of tissue engineering applications.

Recently, an angiogenic therapy based on adipose-derived stem cells (ASCs) in an ischemic model has been reported. This study demonstrates the differentiation of human ASCs (hASCs) into endothelial cells clusters by culturing the cells in the form of three dimensional cell masses (3DCMs), which is based on the adherent activity of ASCs for a substrate. The 3DCM composed of hASCs induced hypoxic conditions and expressed angiogenic factors, such as VEGF. From immunochemical staining analysis, the 3DCMs of hASCs were CD31+, KDR+, and CD34+,whereas monolayer-cultured hASCs were negative for these markers. To evaluate the ability of vasculature to form within 3DCMs, the 3DCMs were mixed in Matrigel/fibrin gel and injected subcutaneously into mice. Mature tubular microvessels perfused with blood were observed in the 3DCM/ge l20days after injection, but not in the gel alone or hASC/gel mixture. Vasculature formed in the 3DCM/gel was recognized by antibodies against human a-SMA, KDR, CD31, and CD34, but not by antibodies against murine antigens. The 3DCMs of hASCs could function as a source of vascular cells for neovascularization, and could also be co-implanted with other cell types.

To accomplish the therapeutic purpose in neural regenerative medicine using stem cells, control of both efficient differentiation into a target tissue and the axon guidance to desired direction are important. Herein, we used multi-walled carbon nanotube (mwCNT) sheets with aligned orientation to differentiate human mesenchymal stem cells (hMSC) into neuronal cells. Human MSCs were attached to aligned CNT sheets with longitudinal stretch in parallel direction to the CNTs. Elongation magnitude of cells was two-folds of the control and most of the cells aligned in sheet-CNT were within 5° angle of the CNT direction. Moreover, a significant synergistic effect on neuronal differentiation and cell adhesion was observed in hMSCs cultured on the CNT sheets. Axon outgrowth was also guided by the CNT pattern. This CNT sheet provides a new biomimetic platform that can regulate morphogenesis and differentiation of stem cells, which would open up the opportunities for tissue repair and regeneration of stem cell therapy.

YIGSR (Tyr-Ile-Gly-Ser-Arg) and IKVAV (Ile-Lys-Val-Ala-Val), which are located in the β1 and α1 chain of laminin, have been demonstrated to promote cell adhesion and growth.[1] A thermoplastic polycarbonate urethane (TPU) is attractive in biomedical applications due to its outstanding physical properties, biostability, and biocompatibility.[2] In this study, we evaluated the effect of the YIGSR/IKVAV surface-conjugated two different morphogic TPUs for their specificity and growth promotability using nerve cell. Two morphologies of TPU substrates, film (MTPU) and aligned fiber (STPU), were prepared by solvent casting and electrospinning methods, respectively. To conjugate the peptides on the surface of TPUs, the substrates were activated by oxygen plasma treatment, and then poly(ethylene glycol) bisamine (PEG-BA) was grafted on the surface as a linker between the TPUs and the peptides. The resulting TPU surfaces were characterized by ATR-FTIR spectra, water contact angle measurement, and XPS. Protein adsorption experiment was carried out to evaluate the protein-resistance of the surfaces. The rate of protein adsorption was significantly reduced after modification. In addition, substrates were shown that have different influence on the nerve cell. The result was may occurred from different chain derivation. These laminin conjugated TPUs are expected that can use for dissimilar aimed neural engineering by means of distinctive interaction. Acknowledgement: This research was supported by the Pioneer Research Center Program through the National Research Foundation of Korea funded by the Ministry of Education, Science and Technology (2010-0019346).

Microfracture of cartilage induces migration of bone marrow-derived mesenchymal stem cells (BMMSCs). However, this treatment often results in fibrocartilage regeneration. Bone morphogenetic protein (BMP)-2 induce the differentiation of BMMSCs into chondrocytes, which can be used for hyaline cartilage regeneration. We tested the hypothesis that long-term delivery of BMP-2 to cartilage defects subjected to microfracture results in regeneration of high quality hyaline-like cartilage. Heparin-conjugated fibrin (HCF) and normal fibrin were used as carriers for the long and short-term delivery of BMP-2, respectively. Rabbit articular cartilage defects were treated with microfracture combined with one of the following: no treatment, fibrin, short-term delivery of BMP-2, HCF or long-term delivery of BMP-2. Eight weeks after treatment, histological analysis and biochemical assay revealed that the long-term delivery of BMP-2 group had the highest GAG content and expression level of collagen type II. Taken together, the long-term delivery of BMP-2 to cartilage defects subjected to microfracture resulted in regeneration of hyaline-like cartilage.

Over the last few years, gene delivery efficiency has been increased to study for the gene therapy. Adeno-associated viral (AAV) vectors are one of the most useful vectors for gene therapy. Therefore it has been influential in biomedical applications. However, AAV vectors have a major limitation for transduction efficiency in stem cells. Here, we report the Hybrid AAV Vector system to overcome the transduction limitations. AAV vectors are formation with cationic polymer PEI and 3,4-dihydroxy-L-phenylalanine (DOPA), and its delivery efficacy was studied in stem cells applications. Compacted hybrid AAV Vector has both sides of advantages each viral and non-viral vector. The AAV vectors are considerably safe and efficient gene delivery vehicles, and PEI is one of the useful cationic polymers that are effective in gene delivery because it displays not only an effective gene carrier but also a buffering capacity which provides a chance to escape from endosome. In addition, DOPA is the major components of mussel’ adhesive proteins, which forms strong covalent and non-covalent interactions with substrates. Hybrid vectors can be used as a powerful tool for gene targeting in neural stem cells.

Cross-linking of collagen using the reactive hydroxy-, amino- and carboxygroups on the collagen molecule has been described previously. Recently, non-toxic cross-linking agent has been described based on water-soluble carbodiimide and N-hydroxysuccimide (EDC-NHS). Also, cross-linking reagents, consisting of natural polymers has a lot of research. In this study Genipin (GP) and Grape Seed Extract (GSE), a significantly less cytotoxic cross-linking agent compared to EDC-NHS, was used to cross-link collagen-CS scaffold for jurkat cell. In other words, we evaluated the effects of cross-linking reagents on the cell growth and cytokine production in three-dimensional culture. These reports showed that cell growth in the EDC-NHS was significantly higher than that of the other groups. Scanning electron microscopy (SEM) revealed the porous surface of each scaffolds maintained their spherical morphology. In addition, cytokine amount through IFN-r, TNF-a, IL-2, and IL-6 assay, that GP and GSE revealed higher than EDC-NHS. GP showed high cross-linking ability, along with toxicity and immune response, respectively. GSE compared with the GP or the EDC-NHS more toxic to the cell itself, given the three-dimensional scaffolds for the culture of cross-linking agent was inappropriate at this time. Thus, cross-linking of the cross-linked scaffold on each culture tests, impact on cells and cytokines secreted by the amount of EDC-NHS creatures of the lowest toxicity was found.

Various medical devices have been researched and have been developed for drug transfer to body. At this time, they have been in vitro evaluated with cell lines (L929, MRC5, WI38, Vero, C-13) for predicts of their biocompatibility in vivo. However, the results of experiments in mesenchymal or epithelial cell culture could not be similarly considered in vivo immune reaction. In this study, we evaluated elutions in cell lines (L929, Jurkat, U937) culture and then the result was compared with in vivo results of injection in guinea pig skin. The elution could not induce erythema, but only positive control induce erythema at guinea pig skin test. But three types of cells showed the differences in the secretion of cytokines (TNF-α, INF-γ) and in survival rate for the HDPE elution, respectively. The results of Jurkat (lymphocyte) and U937 (monocyte) cell line culture were more correlated with in vivo results than the results of L929 (fibroblast) cell line culture. Therefore, we could know that inflammatory cell lines are more effective in the evaluation for biocompatibility of medical devices.

We investigated whether visfatin gene expression is associated with differentiation of neuronal cells. RT-PCR analysis, morphological observations, and immunostaining revealed that CoCl2, a hypoxic mimetic agent, at 75 microM increased the expression of visfatin gene and induced neurite outgrowth in PC12 rat pheochromocytoma cells. In addition, the treatement of visfatin stimulated neurite outgrowth with the increase in the levels of Vigin (visfatin-inducible gene in neuritogenesis) mRNA and protein. Vigin upregulation by visfatin was prevented by an inhibitor of the extracellular signal-regulated kinase 1/2 (ERK1/2) pathway. Furthermore, visfatin-induced neurite outgrowth was also reduced by inhibition of ERK1/2 pathways. Taken together, our results indicate that visfatin-induced neurite outgrowth is composed largely of two sequential steps: the induction of ERK1/2-dependent Vigin gene expression by visfatin and the subsequent Vigin-induced neuritogenesis. These data further suggest an integral role for visfatin- Vigin signaling axis in modulating neurite outgrowth of neuronal cells.

Platelet rich plasma (PRP) is increasingly used in the treatment of wound healing. We have developed heparin-conjugated fibrin (HCF) which can exert controlled release of various growth factors contained in PRP. Here, we hypothesized HCF can deliver growth factors contained in PRP for a long period and enhance the wound healing effect of PRP. PRP was prepared by centrifuging whole blood. Full-thickness (2.0 x 2.0 cm) wounds were created on the dorsum of athymic mice. HCF mixed with PRP and thrombin was applied at the wound sites. No treatment, application of PRP with thrombin, PRP with fibrinogen and thrombin served as controls. Skin regeneration was evaluated by histological and immunohistochemical analyses. Initial burst release and release period dramatically differ depending on the types of the delivery system in vitro. At 12 days after injury, PRP with HCF group showed complete epithelialization of the wound compared to the other groups. The macroscopic wound sizes of PRP with HCF group were statistically smaller than the other groups at 12 days. HCF could be useful for delivery of various heparin-binding growth factors contained in PRP to promote wound healing.

An angiogenic therapy based on adipose-derived stem cells (ASCs) in an ischemic model has been reported. we have established a 3-D cell mass (3DCM) culture to differentiate human ASCs into vascular cells controlling cell adhesion. We found from a human angiogenesis protein array that the 3DCM composed of hASCs induced hypoxic conditions and expressed angiogenic factors, such as VEGF and angiogenin. VEGF was up-regulated in 3DCM in the presence or absence of fetal bovine serum. as compared with monolayered hASCs cultured on TCP. The extracellular matrix plays an important role in modulating vessel formation by changing its composition and structure to induce endothelial migration. We make a plan to identify the secretome of 3DCMs culture through proteome analyses and apply for a angiogenesis therapy following examination in mouse ischemia model.

Adipose tissue-derived stem cells (AT-MSCs) can be extracted from adipose tissue and obtained by a less invasive method and in larger quantities compared with bone marrow–erived MSCs. And many studies have demonstrated that AT-MSCs have differentiate potential to neuronal cells by treating mechanical and chemical methods. The aim of this study is to investigate the effects of sonic vibration (SV) on AT-MSCs and to explore their neuronal differentiation potential. We decided AT-MSCs were exposed to sonic vibration during 4 days at 40 Hz, 1.0 V. After stimulation, we found the differences between sonic vibration exposed group and on-exposed group in terms of cell morphology and RT-PCR electrophoresis products. In the sonic vibration exposed group, RT-PCR indicated that expression level of neuronal markers including NeuroD1, Map2 and NF-L is significantly higher than non-exposed group. So these results suggest that sonic vibration affects MSCs to induce the neuron-like stem cells. And adipose tissue may be an alternative source of stem cell therapy for nervous system injury.

Here we demonstrate that myocardial protection of infracted heart using dual growth factor delivery with self-assembling peptides nanofiber hydrogel (SAP). The SAP forms fibers (5 to 10 nm) and assembles into a 3D scaffold at physiological pH. After left coronary artery ligation in SD rats, growth factors with SAP was injected (n=6, 4 weeks). Capillary and arterial density in SPF group was dramatically increased and ~80 % of the newly formed vessels were matured. Infarct size of SPF was significantly reduced and cardiac function was improved. In conclusion, dual growth factor with SAP is effective to myocardial protection and angiogenesis, and leads to improvement in cardiac function.

Hydroxyapatite (HAp)/carbon nanotubes (CNTs) hybrid composite materials are successfully synthesized via a biomineralization process that employs poly(dopamine) (PDA), a synthetic mimic of mussel adhesive proteins. Creating bio-inorganic composites for regenerative medicine requires appropriate fillers to enhance their mechanical robustness; for example, natural bones are composed mainly of HAp supported by collagen fibers. In this regard, many efforts have been made to harness HAp as a bone substitute through its integration with reinforcing fibrous materials such as CNTs. We found that the formation of a PDA ad-layer on the surface of CNTs changed the hydrophobic CNTs to become bioactive. This enabled efficient interaction between the CNTs and mineral ions (e.g., Ca2+), which facilitated the mineralization of HAp. CNTs functionalized with PDA (CNT-PDA) highly accelerated the formation of HAp when incubated in a simulated body fluid and exhibited a minimal cytotoxic effect on bone osteoblast cells compared to pristine or carboxylated CNTs. Our results show the potential of CNT-PDA as a scaffold material for bone tissue regeneration and implantation.

Stem cells offer therapeutic promise for the treatment of ischemic disease. However, stem cell treatment exhibit limited therapeutic efficacy due to poor engraftment in vivo. Here, we demonstrate that human adipose-derived stem cells (hADSCs) cultured and grafted as spheroids exhibit improved therapeutic efficacy for ischemia disease. Spheroid cultures were more effective in preconditioning hADSCs to a hypoxic environment, upregulating hypoxia-adaptive signals and enhancing secretion of both angiogenic and anti-apoptotic factors compared to monolayer cultures. Moreover, spheroids cell harvesting procedure enabled us to avoid damage caused by harsh proteolytic enzyme treatments. Transplantation of hADSC into ischemica region, hADSC spheroids showed improved cell survival, neovascularization, and limb survival as compared to grafted as dissociated cells. Spheroid cultures prime hADSCs to a hypoxic environment and grafting hADSCs as spheroids to ischemic limbs improve therapeutic efficacy for ischemia treatment due to enhanced cell survival and paracrine effects. Spheroid cell delivery could be a simple and effective strategy for improving stem cell therapy for ischemic diseases.

Type 1 diabetes (T1D) has been known as a disease caused by T cell-mediated autoimmune destruction of pancreatic cells. Generation of insulin-producing cells (IPCs) from various kinds of stem cells have immense potential for the treatment of T1D due to the shortage of pancreas donors. Mesenchymal stem cells (MSCs) are uniquely capable of crossing germinative layers borders. Moreover, MSCs are obtainable in high numbers via ex vivo culture. Many researchers have therefore searched for diverse sources of MSCs, such as bone marrow, Wharton's Jelly, adipose tissue, and periosteum. In this study, we compared the growth potency of three kinds of MSCs derived from different tissues. In addition, in vitro differentiation of those MSCs into IPCs was also investigated. Induced IPCs was confirmed by using immunofluorescence. ELISA was used to measure the level of insulin. By using RT-qPCR, expression levels of insulin genes were detected. It was found that the periosteum-derived progenitor cells (PDPCs) have a potential as a source for the differentiation into IPCs.