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Microfluidics cell encapsulation offers a way to mimic a 3D microenvironment that supports cell growth and proliferation, while also protecting cells from environmental stress. This technique has found extensive applications in tissue engineering and cell therapies. Several studies have demonstrated the advantages of graphene oxide (GO) as an osteogenic inducer; however, the significance of GO on stem cell fate in the single-cell state is still unclear. Here, a microfluidics-based approach is developed for continuous encapsulation of mesenchymal stem cells (MSCs) at the single-cell level using alginate microgels. So, single-layer graphene oxide (slGO) nanosheet is used to be encapsulated inside the alginate droplets. The results of AFM and SEM show that slGO can increase the roughness and reduce the stiffness of alginate hydrogels. The Young's modulus of the alginate and alginate-slGO was obtained as 1414 kPa and 985.9 kPa, respectively. Live/dead assay and fluorescence microscopy images illustrate that slGO can maintain the viability and proliferation of microencapsulated hBMSCs. The obtained results show that slGO increases the mineralization of the encapsulated hBMSCs, so that microgels containing hBMSCs gradually became opaque during 21 days of culture. RT-qPCR results indicate that the expression of OCN, Runx2, and ALP in the alginate-slGO microgels is significantly higher than in the alginate microgels. The expression of OCN and Runx2 in the alginate-slGO microgels is 4.27 and 5.87-fold higher than in the alginate microgels, respectively. It can be concluded that low doses of slGO nanosheets have the potential to be utilized in the development of tissue engineering and bone regeneration. This finding offers a new method for creating injectable tissue transplants that are minimally invasive. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the antioxidant and anti‐inflammatory effects of glucosamine nanoparticles (GNPs) grafted with gallic acid (GNPs‐g‐GA). Glucosamine hydrochloride (G‐HCl) was produced from shrimp shell, and then GNPs synthesized using ionic gelation method. GNPs‐g‐GA was prepared by coupling GNPs with GA via 1‐ethy‐3‐(3‐dimethylaminopropyl)‐carbodiimide (EDC) in combination with N‐hydroxysuccinimide (NHS) cross‐linking agents. The results indicated that the grafting of GA onto GNPs at different ratios increased the average size of the nanoparticles from 195.7 to 294.2 nm with various grafting degrees ranging from 73.3 to 146.4 mg GA/g GNPs‐g‐GA. The SEM images revealed the formation of spherical‐shaped GNPs‐g‐GA nanoparticles with approximate sizes ranging from 275.3 to 303.6 nm. The appearance of characteristic signals in the FT‐IR (C=C, C–O/C–C, and NH2) and 1H‐NMR (H‐2 and H‐6 at 6.95 ppm) spectra and the red shift in UV‐Vis spectrum provided further support of GNPs‐g‐GA successful synthesis. DPPH radical scavenging (from 20.0 to 70.4%) and ABTS radical scavenging (from 18.7 to 79.0%) activities and reducing power (nearly fivefold) sharply improved in GNPs‐g‐GA. Moreover, GNPs‐g‐GA was found nontoxic and drastically reduced the level of nitric oxide release and downregulated the synthesis of TNF‐α, IL‐1β, and IL‐6 in LPS‐induced RAW2647 murine macrophage cells through NF‐κB and MAPKs signaling pathways. Overall, these results suggested that the grafting of GNPs and GA is an effective strategy for the suppression of inflammation response and oxidation reaction in osteoarthritis. [ABSTRACT FROM AUTHOR]

Abstract Background Efficient delivery of anticancer chemotherapies such as paclitaxel (PTX) can improve treatment strategy in a variety of tumors such as breast and ovarian cancers. Accordingly, researches on polymeric nanomicelles continue to find suitable delivery systems. However, due to biocompatibility concerns, a few micellar nanoformulations have exquisitely been translated into clinical uses. Here, we report the synthesis of novel water-soluble nanomicelles using bioactive polyurethane (PU) polymer and efficient delivery of PTX in the human breast cancer MCF-7 cells. Results The amphiphilic polyurethane was prepared through formation of urethane bounds between hydroxyl groups in poly (tetramethylene ether) glycol (PTMEG) and dimethylol propionic acid with isocyanate groups in toluene diisocyanate (TDI). The free isocyanate groups were blocked with phenol, while the free carboxyl groups of dimethylol propionic acid were reacted with triethylamine to attain ionic centers in the polymer backbone. These hydrophobic PTMEG blocks displayed self-assembly forming polymeric nanomicelles in water. The PTX loaded PU nanomicelles showed suitable physical stability, negative zeta potential charge (-43) and high loading efficiency (80%) with low level of critical micelle concentration (CMC). In vitro drug release profile showed a faster rate of drug liberation at pH 5.4 as compared to that of pH 7.4, implying involvement of a pH-sensitive mechanism for drug release from the nanomicelles. The kinetic of release exquisitely obeyed the Higuchi model, confirming involvement of diffusion and somewhat erosion at pH 5.4. These nanomicelles significantly inhibited the growth and proliferation of the human breast cancer MCF-7 cells, leading them to apoptosis. The real time RT-PCR analysis confirmed the activation of apoptosis as result of liberation of cytochrome c in the cells treated with the PTX loaded PU nanomicelles. The comet assay analysis showed somewhat DNA fragmentation in the treated cells. Conclusions Based upon these findings, we propose that the bioactive waterborne polyurethane nanomicelles can be used as an effective nanocarrier for delivery of anticancer chemotherapies such as paclitaxel.