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Multifunctional materials are urgently required for sensing and actuation purposes in microfluidic devices. In this study, poly(dimethylsiloxane) (PDMS) filled with Cu and Ag nanoparticles was prepared and its electrical conductivity (EC), thermal conductivity (TC), and mechanical properties were investigated. EC investigations showed that all the prepared compositions had a nearly similar percolation threshold of around 10 vol% of filler. However, the EC of nanocomposites filled with both Cu and Ag (PDMS/Cu/Ag) was about 1.8 S/cm, which was 200% higher compared with that of other compositions (0.3 and 0.6 S/cm). TC was found to undergo profound increase of 10.5‐fold (1.68 W.m−1.K−1 for PDMS/Cu/Ag) when compared with that of the insulating base polymer (0.16 W.m−1.K−1). Evaluation of mechanical properties demonstrated that Young's modulus of PDMS increased by 270% after adding the filler content, but the tensile strength showed a notable reduction of 12%. The final result of this study showed that PDMS/Cu/Ag nanocomposites could be considered as a suitable novel material in microchannel preparation and microfluidic devices. POLYM. COMPOS., 40:4093–4101, 2019. © 2019 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

Over the past two decades calcium silicate (Ca–Si) based ceramics have been introduced as bioactive materials for bone tissue engineering applications and repairing bone defects. Recently, it is reported that zirconium modified calcium‐silicate‐based (Ca3ZrSi2O9, Baghdadite) ceramics stimulate cell proliferation and osteogenic differentiation of osteoblasts. The aim of this work was preparation, characterization, and evaluation of biological properties of Baghdadite in the nanoparticles form. These nanoparticles were synthesized by sol‐gel method and were annealed at 1150°C. Fabricated nanoparticles were investigated using XRD, FE‐SEM, EDX, and MTT in vitro, then implanted to the rabbit tibia as a bone animal model. The characterization results showed that nanoparticles with expected composition were successfully synthesized using sol‐gel method. According to MTT result, these nanoparticles were nontoxic. In addition, the proliferation of bone marrow derived mesenchymal stem cells was increased after 96 hours of culturing in the presence of nanoparticles compared to the control. Histopathological results also demonstrated that the defected bone was completely regenerated when implanted with nanoparticles after 6 weeks. Taking together, according to the results, Ca3ZrSi2O9 nanoparticles as a bioceramic with excellent biological properties can be applied for improvement of bone lesions healing process in the orthopedic and dental application. [ABSTRACT FROM AUTHOR]

In this study, a ceramic‐coated nanofibrous scaffold has been fabricated to biomimic the microstructure of natural extracellular matrix and the stiffening inorganic compartment of bone. Poly‐l‐lactic acid (PLLA) nanofibers were electrospun and exposed to oxygen plasma to induce hydrophilicity and promote ceramic adsorption. Hardystonite (HS), which possesses superior osteoinduction potential over hydroxyapatite, was coated on plasma‐treated PLLA nanofibers by drenching the nanofibers in HS suspension. Pure and composite PLLA‐based scaffolds were characterized in terms of physical and biological properties. In vitro cultivation of adipose‐derived mesenchymal stem cells (AMSCs) on the scaffolds displayed that the composite scaffold is able to further support cell attachment and proliferation. In case of osteogenic differentiation of AMSCs, HS coating significantly increased the synthesis and activity of alkaline phosphate over 21 days period. In addition, the composite scaffold showed improved mineralization. The expression level of osteonectin and osteocalcin genes was significantly enhanced by HS coating of nanofibers. The biological improvement of PLLA nanofibrous matrix in the presence of HS nanoparticles could either be attributed to the release and stimulatory effect of constituent ions of HS or to the modification of chemico‐physical properties of the resultant ceramic by silicon and zinc present in HS. [ABSTRACT FROM AUTHOR]

ABSTRACT Considerable efforts have been devoted toward the development of electrospun scaffolds based on poly(ε-caprolactone) (PCL) for bone tissue engineering. However, most of previous scaffolds have lacked the structural and mechanical strength to engineer bone tissue constructs with suitable biological functions. Here, we developed bioactive and relatively robust hybrid scaffolds composed of diopside nanopowder embedded PCL electrospun nanofibers. Incorporation of various concentrations of diopside nanopowder from 0 to 3 wt % within the PCL scaffolds notably improved tensile strength (eight-fold) and elastic modulus (two-fold). Moreover, the addition of diopside nanopowder significantly improved bioactivity and degradation rate compared to pure PCL scaffold which might be due to their superior hydrophilicity. We investigated the proliferation and spreading of SAOS-II cells on electrospun scaffolds. Notably, electrospun PCL-diopside scaffolds induced significantly enhanced cell proliferation and spreading. Overall, we concluded that PCL-diopside scaffold could potentially be used to develop clinically relevant constructs for bone tissue engineering. However, the extended in vivo studies are essential to evaluate the role of PCL-diopside fibrous scaffolds on the new bone growth and regeneration. Therefore, in vivo studies will be the subject of our future work. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44433. [ABSTRACT FROM AUTHOR]

We have investigated the combination effects of bioceramics and poly(lactide-co-glycolide) (PLGA) on bone reconstruction in calvarial critical size defects using a rat model. Willemite (Zn2SiO4) ceramics were prepared and coated on the surface of electrospun fabricated scaffolds. After scaffolds and nanoparticles characterization, osteoconductivity of the construct was analyzed using digital mammography, multislice spiral-computed tomography (MSCT) imaging, and histological analysis. Eight weeks after implantation, no sign of inflammation was observed at the site of the osseous defect. The results showed that the ceramics supported bone regeneration and highest bone reconstruction were observed in willemite-coated PLGA. This suggests that electrospun PLGA nanofibers coated with BG are potential candidate implants for bone tissue engineering applications. [ABSTRACT FROM AUTHOR]