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Introduction: Treatment of criticalsized bone defects is challenging. Tissue engineering as a state-of-the-art method has been concerned with treating these nonself-healing bone defects. Here, we studied the potentials of new three-dimensional nanofibrous scaffolds (3DNS) with and without human adipose mesenchymal stem cells (ADSCs) for reconstructing rat criticalsized calvarial defects (CSCD). Methods: Scaffolds were made from 1-polytetrafluoroethylene (PTFE), and polyvinyl alcohol (PVA) (PTFE/PVA group), and 2- PTFE, PVA, and graphene oxide (GO) nanoparticle (PTFE/PVA/GO group) and seeded by ADSCs and incubated in osteogenic media (OM). The expression of key osteogenic proteins including Runt-related transcription factor 2 (Runx2), collagen type Iα (COL Iα), osteocalcin (OCN), and osteonectin (ON) at days 14 and 21 of culture were evaluated by western blot and immunocytochemistry methods. Next, 40 selected rats were assigned to five groups (n=8) to create CSCD which will be filled by scaffolds or cellcontaining scaffolds. The groups were denominated as the following order: Control (empty defects), PTFE/PVA (PTFE/PVA scaffolds implant), PTFE/PVA/GO (PTFE/PVA/GO scaffolds implant), PTFE/PVA/Cell group (PTFE/PVA scaffolds containing ADSCs implant), and PTFE/PVA/GO/Cell group (PTFE/PVA/GO scaffolds containing ADSCs implant). Six and 12 weeks after implantation, the animals were sacrificed and bone regeneration was evaluated using computerized tomography (CT), and hematoxylin-eosin (H&E) staining. Results: Based on the in-vitro study, expression of bone-related proteins in ADSCs seeded on PTFE/PVA/GO scaffolds were significantly higher than PTFE/PVA scaffolds and TCPS (P<0.05). Based on the in-vivo study, bone regeneration in CSCD were filled with PTFE/PVA/GO scaffolds containing ADSCs were significantly higher than PTFE/PVA scaffolds containing ADSCs (P<0.05). CSCD filled with cell-seeded scaffolds showed higher bone regeneration in comparison with CSCD filled with scaffolds only (P<0.05). Conclusion: The data provided evidence showing new freeze-dried nanofibrous scaffolds formed from hydrophobic (PTFE) and hydrophilic (PVA) polymers with and without GO provide a suitable environment for ADSCs due to the expression of bone-related proteins. ADSCs and GO in the implanted scaffolds had a distinct effect on the bone regeneration process in this in-vivo study. [ABSTRACT FROM AUTHOR]

Mesenchymal stem cells (MSCs) are non-hematopoietic, multipotent progenitor cells which reside in bone marrow (BM), support homing of hematopoietic stem cells (HSCs) and self-renewal in the BM. These cells have the potential to differentiate into tissues of mesenchymal origin, such as fibroblasts, adipocytes, cardiomyocytes, and stromal cells. MSCs can express surface molecules like CD13, CD29, CD44, CD73, CD90, CD166, CXCL12 and toll-like receptors (TLRs). Different factors, such as TGF-β, IL-10, IDO, PGE-2, sHLA-G5, HO, and Galectin-3, secreted by MSCs, induce interaction in cell to cell immunomodulatory effects on innate and adaptive cells of the immune system. Furthermore, these cells can stimulate and increase the TH2 and regulatory T-cells through inhibitory effects on the immune system. MSCs originate from the BM and other tissues including the brain, adipose tissue, peripheral blood, cornea, thymus, spleen, fallopian tube, placenta, Wharton's jelly and umbilical cord blood. Many studies have focused on two significant features of MSC therapy: (I) MSCs can modulate T-cell-mediated immunological responses, and (II) systemically administered MSCs home in to sites of ischemia or injury. In this review, we describe the known mechanisms of immunomodulation and homing of MSCs. As a result, this review emphasizes the functional role of MSCs in modulating immune responses, their capability in homing to injured tissue, and their clinical therapeutic potential. [ABSTRACT FROM AUTHOR]

Breast cancer is the most frequently occurring cancer among women throughout the world. Natural compounds such as curcumin hold promise to treat a variety of cancers including breast cancer. However, curcumin's therapeutic application is limited, due to its rapid degradation and poor aqueous solubility. On the other hand, previous studies have stated that drug delivery using nanoparticles might improve the therapeutic response to anticancer drugs. Poly(N-isopropylacrylamide-co-methacrylic acid) (PNIPAAm–MAA) is one of the hydrogel copolymers utilized in the drug delivery system for cancer therapy. The aim of this study was to examine the cytotoxic potential of curcumin encapsulated within the NIPAAm-MAA nanoparticle, on the MCF-7 breast cancer cell line. In this work, polymeric nanoparticles were synthesized through the free radical mechanism, and curcumin was encapsulated into NIPAAm-MAA nanoparticles. Then, the cytotoxic effect of curcumin-loaded NIPAAm-MAA on the MCF-7 breast cancer cell line was measured by MTT assays. The evaluation of the results showed that curcumin-loaded NIPAAm-MAA has more cytotoxic effect on the MCF-7 cell line and efficiently inhibited the growth of the breast cancer cell population, compared with free curcumin. In conclusion, this study indicates that curcumin-loaded NIPAAm-MAA suppresses the growth of the MCF-7 cell line. Overall, it is concluded that encapsulating curcumin into the NIPAAm-MAA copolymer could open up new avenues for breast cancer treatment. [ABSTRACT FROM AUTHOR]

Breast cancer is the most commonly diagnosed cancer and the leading cause of cancer death among women worldwide. Herbal medicines have tremendous potential as promising agents for the treatment of cancer. Curcumin is a natural polyphenol which has many anticancer effects. Because of its low aqueous solubility, low bioavailability, and quick degradation and metabolism, curcumin was released using PLGA-PEG nanoparticles. Herein, the efficiency of pure curcumin and curcumin-loaded PLGA-PEG in MCF-7 human breast cancer cell lines was studied.1H NMR, FT-IR and SEM demonstrated PLGA-PEG structure and curcumin loaded on nanoparticles. Subsequently, the cytotoxic effects of free curcumin and curcumin-loaded PLGA-PEG were determined via an MTT assay. Our study confirmed that curcumin-loaded PLGA-PEG has more cytotoxic effects on the MCF-7 breast cancer cell line and could be exploited as a potential source for developing novel drugs against breast cancer. [ABSTRACT FROM PUBLISHER]

Nowadays, mesenchymal stem cells (MSCs) are the most widely used cell sources for bone regenerative medicine. Electrospun polyacrylonitrile (PAN)-based scaffolds play an important role in bone tissue engineering due to their good mechanical properties, which could be enhanced by the presence of nanoparticles such as nanoclay. This study evaluated the in-vitro effect of different concentrations of nanoclay in surface characteristic properties of PAN-based electrospun nanofiber scaffolds and the osteogenic differentiation ability of adipose-derived mesenchymal stem cells (AD-MSCs). After electrospinning nanofibers, their structure were assessed through some characterization tests. Then AD-MSCs isolation and characterization were done, and the cell attachment and the biocompatibility were determined. Finally, osteogenic differentiation-related markers, genes, and proteins were studied. Clay-PAN25% electrospun nanofiber scaffold could support attachment, proliferation, and osteogenic differentiation of AD-MSCs better than other groups. Also, nanoclay could enhance the properties of PAN-based scaffolds, such as fiber diameter, topography, surface charge, hydrophilicity, roughness, and degradation, as well as osteogenic differentiation of cells. As a result, Clay-PAN25% with the highest concentration of nanoclay was found as a promising biodegradable and cost-effective scaffold for osteogenic differentiation of AD-MSCs.