Journal of Applied Biomaterials & Functional Materials最新文献

The insufficient osteogenesis of magnesium phosphate cements (MPCs) limits its further application. It is significant to develop a bioactive MPC with osteogenic properties. In this work, MPCs were reinforced by zinc oxide nanoparticles (ZnO-NPs). The composition, microstructure, setting time, compressive strength and degradation of ZnO-NPs/MPCs (ZNMPCs) were evaluated. The results showed that the setting times of MPCs were prolonged from 8.2 to 25.3 min (5.0ZNMPC). The exothermic temperatures were reduced from 45.8 ± 0.4℃ (MPCs) to 39.3 ± 0.5℃ (1.0ZNMPC). The compressive strength of ZNMPC composite cement with 1 wt. % ZnO-NPs (1.0ZNMPC) was the highest (42.9 MPa) among all the composite cements. Furthermore, the ZNMPCs were cultured with mouse bone marrow mesenchymal stem cells (mBMSCs). The results yielded that the ZNMPCs exhibited good cytocompatibility with enhanced differentiation, proliferation, and mineralization on mBMSCs, and it also pronouncedly elevated the expressions of genes and proteins involving osteogenesis. These findings suggested that ZNMPCs could drive the differentiation toward osteogenesis and mineralization of mBMSCs, providing a simple way to the MPC with enhanced osteogenesis for further orthopedic applications.

Applications: The interaction of nanoparticles and base solvents of different nature attained much interest of the researchers in the recent time. These use in medication, detection of cancer cells, applied thermal engineering, and electrical and mechanical engineering. Among the broad range of applications, investigation of nanofluid through converging/diverging channel is important which is of much interest in the field of medical sciences.

Purpose and methodology: The core purpose of this study is to introduce a new heat transfer model for two natures of nanofluids with bi host solvents. The model in hand achieved through nanofluid expressions, similarity equations and induction of novel dissipation effects. At later stage, numerical treatment is performed to explore the actual behaviour of nanofluids inside the oblique walls which is very important.

Core findings: From the drawn results, it is found that the motion could be controlled by expanding the channel walls ($\alpha =5^o$) and high Re and in Al₂O₃-H₂O it is optimum. The nanofluids based on Al₂O₃ and C₂H₆O₂ have much ability to transmit heat than the other nanofluids. Moreover, dissipation effects ($Ec=0.1,0.2,0.3,0.4$) played significant role and boosted the temperature while keeping $Re=70,\alpha =5^o$ and $\alpha =-5^o$, respectively. Also, the study is validated and achieved good agreement between existing and the current study.

The objective of this study was to determine the antimicrobial potential of AH plus supplemented with bismuth lipophilic nanoparticles (BisBAL NPs) on the growth of Enterococcus faecalis isolated from patients with endodontic infections. BisBAL NPs, synthesized with the colloidal method, were characterized, in its pure form or AH Plus-absorbed, by energy-dispersive X-ray spectroscopy and scanning electron microscopy (EDS-SEM). Antimicrobial activity was evaluated with disc diffusion assays, and antibiofilm activity with fluorescence microscopy. BisBAL NP-supplemented AH Plus had a 4.9 times higher antimicrobial activity than AH Plus alone (p = 0.0001). In contrast to AH Plus alone, AH Plus supplemented with BisBAL NP inhibited E. faecalis biofilm formation. The sealing properties of AH plus were not modified by the incorporation of BisBAL NPs, which was demonstrated by a 12-day split-chamber leakage assay with daily inoculation, which was used to evaluate the possible filtration of E. faecalis. Finally, BisBAL NP-supplemented AH plus-BisBAL NPs was not cytotoxic for cultured human gingival fibroblasts. Their viability was 83.7% to 89.9% after a 24-h exposure to AH Plus containing 50 and 10 µM BisBAL NP, respectively. In conclusion, BisBAL NP-supplemented AH Plus constitutes an innovative nanomaterial to prevent re-infection in endodontic patients without cytotoxic effects.

Zirconia based ceramics are giving new hope in hard tissues replacement and implants application. Among the three forms of zirconia (ZrO₂), tetragonal form (t-ZrO₂) possess high mechanical stability in comparison with the other two which makes it suitable for fabricating biomedical implants with enhanced osteo activity. Here, tetragonal phase nanospheres consisting of silica stabilised zirconia (1:1) were prepared via sol gel method. The nanospheres exhibit sea urchin type morphology as observed from FESEM analysis. XRD patterns confirm the formation of t -SiO₂-ZrO₂ binary phase after high temperature calcination at 650°C. The immersion studies in SBF help in the formation of a layer of apatite in a gradual manner over the pallets for the period of 7, 14, 21 and 28 days which was confirmed by XRD, FTIR analysis. Moreover, t- SiO₂ - ZrO₂ samples were subjected to cytotoxicity tests through MTT assay on MG-63 cell lines. Antibacterial properties were investigated quantitatively using colony forming unit method against both gram positive as well as gram-negative bacteria.