Green synthesis of Fe3O4 nanoparticles stabilized by a Garcinia mangostana fruit peel extract for hyperthermia and anticancer activities

Fe3O4 nanoparticles (Fe3O4 NPs) with multiple functionalities are intriguing candidates for various biomedical applications. Materials and Methods: This study introduced a simple and green synthesis of Fe3O4 NPs using a low-cost stabilizer of plant waste extract rich in polyphenols content with a well-known antioxidant property as well as anticancer ability to eliminate colon cancer cells. Herein, Fe3O4 NPs were fabricated via a facile co-precipitation method using the crude extract of Garcinia mangostana fruit peel as a green stabilizer at different weight percentages (1, 2, 5, and 10 wt.%). The samples were analyzed for magnetic hyperthermia and then in vitro cytotoxicity assay was performed. Results: The XRD planes of the samples were corresponding to the standard magnetite Fe3O4 with high crystallinity. From TEM analysis, the green synthesized NPs were spherical with an average size of 13.42±1.58 nm and displayed diffraction rings of the Fe3O4 phase, which was in good agreement with the obtained XRD results. FESEM images showed that the extract covered the surface of the Fe3O4 NPs well. The magnetization values for the magnetite samples were ranging from 49.80 emu/g to 69.42 emu/g. FTIR analysis verified the functional groups of the extract compounds and their interactions with the NPs. Based on DLS results, the hydrodynamic sizes of the Fe3O4 nanofluids were below 177 nm. Furthermore, the nanofluids indicated the zeta potential values up to −34.92±1.26 mV and remained stable during four weeks of storage, showing that the extract favorably improved the colloidal stability of the Fe3O4 NPs. In the hyperthermia experiment, the magnetic nanofluids showed the acceptable specific absorption rate (SAR) values and thermosensitive performances under exposure of various alternating magnetic fields. From results of in vitro cytotoxicity assay, the killing effects of the synthesized samples against HCT116 colon cancer cells were mostly higher compared to those against CCD112 colon normal cells. Remarkably, the Fe3O4 NPs containing 10 wt.% of the extract showed a lower IC50 value (99.80 μg/mL) in HCT116 colon cancer cell line than in CCD112 colon normal cell line (140.80 μg/mL). Discussion: This research, therefore, introduced a new stabilizer of Garcinia mangostana fruit peel extract for the biosynthesis of Fe3O4 NPs with desirable physiochemical properties for potential magnetic hyperthermia and colon cancer treatment

The use of recycled aggregate concrete of equal compressive strength in reinfornced concrete beams

One area for sustainable engineering is the efficient use of recycled aggregates obtained from construction and demolition and also as by-products derived from industrial waste that optimises economic and environmental benefits. For the past five decades, studies on the effect of coarse recycled aggregates (RCA) on properties of concrete have been going on, and in fact, none of them reported that good quality coarse RCA, from the mechanical point of view, is unsustainable for structural use. However, according to the limits stated in BS EN 8500 part 2 (2006), at least 87% of the coarse RCA shall be obtained by crushing old hardened concrete debris. As it was impossible to obtain such good quality aggregates from existing plants, coarse recycled aggregate (RA*) containing 60% of coarse RCA, 10% asphalt, 10% brick, 15% unbound aggregate, and 5% fines and other materials was used in this study. The main aim of this study was to determine and compare the structural properties of natural aggregate concrete (NAC) and recycled aggregate concrete (RAC) of equal compressive strength by using different percentage of course RA* and to investigate the suitability of coarse RA* for use in steel-reinforced concrete elements. The study was carried out in three phases. Phase 1 involved the characterisation of the aggregates through a testing regime which include physical and mechanical assessments to study their possible application in concrete production. It was found that the aggregates were suitable to produce normal concrete. For the Phase 2, the effect of the coarse RA* content (up to 100%) on the main properties of concrete was investigated. The results showed that there was a gradual decrease in slump (up to 24%), compressive strength (up to 21%), flexural strength (up to 10%) and modulus of elasticity (up to 30%) as the percentage of coarse RA* increased up to 100%. Thereafter, NA concrete and RA concrete with the same slump and compressive strength made with 100% Portland cement (PC) only and also with a combination of 70% PC and 30% pulverised fuel ash (PFA), were produced. Flexural strength, modulus of elasticity, drying shrinkage, and creep were determined and compared. The compressive strength of RA concretes was increased by lowering the w/c ratio through reducing the free water content. For the Phase 3, pull-out test was carried out using 16mm and 20mm reformed bars embedded in concrete cylinders made with equal strength NA and RA concretes to investigate the bonding strength. It was discovered that the coarse RA* content had no significant effect on the values of pull-out force. Then, for studying flexural properties (cracking load, ultimate load, deflection, strain in rebar, strain in concrete, and pattern of cracks) of steel-reinforced recycled concrete (RRC) beams, two types of beam sections (under-reinforced and over-reinforced) were made with equal strength NA and RA concretes and tested. It was discovered that the difference in ultimate load values was negligible. Although higher deflections were observed for RA beams, the deflections were still within acceptable limits. Overall, it was concluded that, the flexural behaviour of steel-RRC beams made with equal strength concrete is not considerably affected by the presence of coarse RA*, as well as PFA, and the differences were minor with no practical significance. However, due to effect of coarse RA* on the shrinkage and creep strains, their use in structural elements prone to such deformations may require some special considerations

Green synthesis of Fe3O4 nanoparticles for hyperthermia, magnetic resonance imaging and 5-fluorouracil carrier in potential colorectal cancer treatment

Magnetite nanoparticles (Fe3O4 NPs) have received considerable attention in various biomedical applications due to their fascinating properties and multiple functionalities. In this multidisciplinary study, Fe3O4 NPs were produced by an inexpensive co-precipitation technique and using four different weight percentages of Punica granatum fruit peel extract as a green stabilizer. From the image of transmission electron microscopy, the NPs showed spherical shapes with an average size of 14.38 nm. Results of UV–VIS spectroscopy and bandgap indicated successful preparation of the Fe3O4 NPs stabilized with the extract. Adding the stabilizer concentration improved the particle zeta potential from −29.24 to −35.62 mV. Thermoresponsive performance of the Fe3O4 nanofluids with the green extract could render a remarkable heating capability under the hyperthermia condition. Magnetic resonance imaging (MRI) analysis presented that the samples possessed acceptable MRI signals. An anticancer drug 5-fluorouracil was successfully loaded onto the Fe3O4 NPs containing 2 weight percentage of the extract, which indicated a maximum release of 79% in a media with pH 7.4. In cytotoxicity assays, the drug-loaded Fe3O4 NPs at 15.62 and 31.25 µg.ml−1 concentration eliminated 29% and 35% of HCT116 colorectal cancer cells, respectively. This study, therefore, introduced that the green-synthesized Fe3O4 NPs can be a promising candidate for magnetic hyperthermia therapy, MRI nanoagents and drug delivery in colorectal cancer