Releasing and structural/mechanical properties of nano-particle/Punica granatum (Pomegranate) in poly(lactic-co-glycolic) acid/fibrin as nano-composite scaffold.

The effect of poly(lactic­co­glycolic acid) (PLGA) on structure, degradation, drug release and mechanical properties of fibrin/pomegranate(F/POM)-based drug­eluting scaffolds have been studied comprehensively. METHODS AND MATERIAL: Nanoparticle-fibrin is prepared from thrombin and fibrinogen dissolved in NaOH and HCl. Then pomegranate powder is added to it. Nanoparticles/pom are provided by freeze drying and freeze milling. The 3-D scaffold of poly(lactide-co­glycolic acid) (PLGA) was prepared via salt­leaching solvent/casting leaching method and impregnated with nanofibrin-pom. Structural and chemical component of the scaffolds were evaluated by transmission and scanning electron microscopy and furrier transmission infrared spectroscopy, respectively. Moreover, the scaffolds were characterized from the degradation rate and drug releasing rate points of view of human Adipose Derive Stem Cells (hADSCs). Cytotoxicity effects of the scaffold were evaluated on hADSCs via MTT assay. RESULTS: The results showed that the size of nanoparticles was about 100 nm. The scaffold had a slow degradation rate and it caused a sustained release pattern of pom. MTT assay indicated that nanoparticles had no cytotoxicity and fibrin-pom nanoparticles increased compressive strength of PLGA/scaffolds dramatically and also caused a proper compressive modulus. CONCLUSIONS: By adding F/POM nanoparticle to PLGA and fabricating a three­dimensional nanocomposite scaffold (PLGA/F/POM nanoparticle), special physical and mechanical properties also suitable for drug release and cell behavior were achieved, which makes it suitable for cartilage tissue engineering applications (Tab. 1, Fig. 7, Ref. 53) Keywords: hybrid composites, drug delivery, carrier, nanoparticles, scaffold.

Comparison between the effect of kartogenin and TGFß3 on chondrogenesis of human adipose- derived stem cells in fibrin scaffold.

BACKGROUND: Due to very sluggish turnover at the molecular and cellular level, the healing of chondral damages has been considered difficult. In the current study, the effects of the Kartogenin, a small heterocyclic molecule on chondrogenic differentiation of stem cells was compared to TGF-ß3. METHODS: Human Adipose-Derived Stem Cells were extracted during an elective surgery. Cell viability was estimated by MTT assay, differentiated cells evaluated by histological and immunohistochemical techniques. Expression of cartilage specific genes (SOX9, Aggrecan, type II and X collagens) assessed by real-time PCR. RESULTS: The real-time PCR assay has revealed the expression of gene marker of chondrogenesis, SOX9, Aggrecan and type II collagen, both in Kartogenin and TGFß3 groups compared to the control group, significantly (p < 0.05). A low expression level of collagen type X as a hypertrophic marker was seen in cartilage produced by using Kartogenin. Meanwhile, the level of type X collagen protein in Kartogenin group was significantly decreased (p > 0.05) compared to TGF-ß3 group. CONCLUSION: Kartogenin was suitable for successful chondrogenic differentiation of human adipose- derived stem cells and a suppressor of the consequent hypertrophy (Tab. 1, Fig. 5, Ref. 31).

The evaluation of toxicity of carbon nanotubes on the human adipose-derived-stem cells in-vitro.

BACKGROUND: Carbon nanotubes (CNTs) have a large variety of applications in tissue engineering and biomedical devices. The biocompatibility and cytotoxicity of CNTs have been studied widely, however, up until now; there was uncertainty on how nanosized materials behave in the human body and stem cells. The current study describes the functionalized carbon nanotubes on adipose-derived stem cells (ADSCs) for viability and proliferation purposes in vitro. MATERIALS AND METHODS: After chemical modification of the CNTs, the ADSCs were cultured in Dulbecco's Modified Eagle's. Medium (DMEM) having doses of 0.1, 1, 10, 20, 50, and 100 µg/ml of CNTs. On the third and seventh days of the experiment, the cellular viability, proliferation, and stemness were determined, using the MTT, trypan Blue, and flow cytometry assays in variable CNTs dosage. RESULTS: In doses of 0.1 and 1 µg/ml, the expression of the surface markers were similar to the control groups on day three, but decreased in higher dosages on day seven. The viability of both groups was the same on day three, but in comparison to the control groups, was found to decrease in the higher dosages on day seven. CONCLUSION: The effect of CNTs on the viability and proliferation of ADSCs is a function of time and the doses used. Through further investigation by using these particles, we expect that we should be able to increase the viability and proliferation of ADSCs.

The apoptotic effects of sirtuin1 inhibitor on the MCF-7 and MRC-5 cell lines.

Sirtuin1 (SIRT1) is an enzyme that deacetylates histones and several nonhistone proteins including p53 during stress and plays an important role in the survival of tumor cells. Hereby, this study describes the potency of salermide as a SIRT1 inhibitor to induce apoptosis in the MCF-7 and MRC-5 cell lines. MCF7 and MRC-5 cell lines were cultured in RPMI-1640 and treated with or without salermide at concentration of 80.56 µmol/L, based on the half-maximal inhibitory concentration (IC50) index at different times (24, 48 and72 h). The IC50 value was established for the salermide in MCF-7. The percentage of apoptotic cells was measured by flow cytometry. Real-time quantitative RT-PCR was performed to estimate the mRNA expression of sirtuin1 in MCF-7 and MRC-5 with salermide at different times. ELISA and Bradford protein techniques were used to detect endogenous levels of total and acetylated p53 protein generated in MCF-7 and MRC-5 cells. Our findings indicated that salermide can induce apoptosis in MCF-7 significantly more effective than MRC-5 cells. We showed that the expression of SIRT1 was dramatically down-regulated by increasing the time of salermide treatment in MCF-7 but not MRC-5 and that the acetylated and total p53 protein levels were increased more in MCF-7 than MRC-5. Salermide, by decreasing the expression of sirtuin1 gene, can induce acetylation of P53 protein and consequently induce significant cell death in MCF-7 that was well tolerated in MRC-5.

A comparison of tissue-engineered bone from adipose-derived stem cell with autogenous bone repair in maxillary alveolar cleft model in dogs.

This study was designed to compare bone regeneration of tissue-engineered bone from adipose-derived stem cell and autogenous bone graft in a canine maxillary alveolar cleft model. In this prospective clinical trial, mesenchymal stem cells (MSCs) were isolated from subcutaneous canine adipose tissue. Undifferentiated cells were incubated with a 3mm×3mm×3mm hydroxyapatite/beta-tricalcium phosphate scaffold, in specific osteogenic medium for 21 days. Four mongrel dogs were prepared by removal of two of the three incisors bilaterally and a 15mm defect in bone was created from crest to nasal floor. After healing, repair was followed by a tissue engineered bone graft from adipose-derived stem cells on one side and corticocancellous tibial auto graft on the other side. Bone regeneration was evaluated by histomorphometry on days 15 and 60 after implantation. The data were analysed with descriptive and t test methods (α=0.05). Bone formation on the autograft sides was higher than on the stem cell sides at 15 and 60 days, 45% and 96% versus 5% and 70%, respectively. Differences between the two groups at 15 and 60 days were significant (p=0.004 and 0.001, respectively). Although autograft is still the gold standard for bone regeneration, tissue engineered bone may provide an acceptable alternative.

Effects of human placental serum on proliferation and morphology of human adipose tissue-derived stem cells.

Media used for tissue culture may have significant effects on the growth and morphology of the adipose tissue-derived stem cells (ADSCs). As fetal bovine serum (FBS) may induce an immunological reaction and health risks, this study was designed to evaluate and compare the effects of human placental serum (HPS) on the proliferation and morphology of hADSCs. We cultured hADSCs for at least three passages in four different culture media containing either FBS, HPS, autologous serum (AS) or human allogeneic serum (HAS). Morphological and immunophenotypic characteristics, as well as proliferation rates of the hADSCs were determined. The rates of proliferation of hADSCs seemed as follows: AS≥HPS>HAS>>FBS. Morphologically, hADSCs isolated and expanded in medium containing HPS were similar to those grown in medium containing AS, whereas the morphology of cells cultured in human sera was different in comparison with FBS-ADSCs cultures. The immunophenotypic markers of hADSCs grown up in medium containing placental serum such as CD44+, CD90+ and CD105+, were similar to hADSCs grown up in media containing other sera. These results indicate that medium enriched with HPS provided a better microenvironment for hADSCs in comparison with medium enriched with commercially available FBS, and other human sera.