Poly(Caprolactone)-Poly(N-Isopropyl Acrylamide)-Fe₃O₄ Magnetic Nanofibrous Structure with Stimuli Responsive Drug Release

Poly(caprolactone; PCL)—poly(N‐isopropylacrylamie; PNIPAAm)—Fe3O4 fiber, that can be magnetically actuated, is reported. Here, a structure is engineered that can be utilized as a smart carrier for the release of chemotherapeutic drug via magneto‐thermal activation, with the aid of magnetic nanoparticles (MNPs). The magnetic measurement of the fibers revealed saturation magnetization values within the range of 1.2–2.2 emu g−1. The magnetic PCL‐PNIPAAm‐Fe3O4 scaffold shows a specific loss power value of 4.19 W g−1 at 20 wt% MNPs. A temperature increase of 40 °C led to a 600% swelling after only 3 h. Doxorubicin (DOX) as a model drug, demonstrates a controllable drug release profile. 39% ± 0.92 of the total drug loaded is released after 96 h at 37 °C, while 25% drug release in 3 h at 40 °C is detected. Cytotoxicity results show no significant difference in cell attachment efficiency between the MNP‐loaded fibers and control while the DOX‐loaded fibers effectively inhibited cell proliferation at 24 h matching the drug release profile. The noncytotoxic effect, coupled with the magneto‐thermal property and controlled drug release, renders excellent potential for these fibers to be used as a smart drug‐release agent for localized cancer therapy

Solidification behavior and microstructural features of the cast and HIPed N-bearing Ti–48Al–2Cr–2Nb intermetallic alloys

Copyright © 2023 The Author(s). Effect of N addition (0.5, 1, and 2 at. %) on solidification behavior and microstructural features of the cast and hot isostatically pressed (HIPed) Ti–48Al–2Cr–2Nb (4822) intermetallic alloy was investigated. Alloys were fabricated using vacuum arc re-melting followed by HIPing. The results showed that N addition changes the primary β phase dendrites to α phase. The morphological uniformity of the as-cast microstructures was notably increased by N addition. In addition, N addition beyond its solubility limit led to the formation of primary Ti2AlN precipitates located within lamellar colonies. A possible mechanism for nucleation of the Ti2AlN precipitates is proposed. Furthermore, N addition caused much more microstructure stability during HIPing. Although a duplex structure was formed after HIPing in the 4822 alloy, N addition decreased the formation of this structure. Moreover, highly extended network of secondary Ti2AlN precipitates were formed in almost all of (α2+γ) lamellas interfaces in the N-bearing alloys.Iran National Science Foundation (research project no. 98006118)

EBSD characterization of cryogenically rolled type 321 austenitic stainless steel

Electron backscatter diffraction was applied to investigate microstructure evolution during cryogenic rolling of type 321 metastable austenitic stainless steel. As expected, rolling promoted deformation-induced martensitic transformation which developed preferentially in deformation bands. Because a large fraction of the imposed strain was accommodated by deformation banding, grain refinement in the parent austenite phase was minimal. The martensitic transformation was found to follow a general orientation relationship, {111}γ||{0001}ε||{110}α′ and 〈110〉γ||〈11-20〉ε||〈111〉α′, and was characterized by noticeable variant selection

The Effect of Process Parameters on the Synthesis of Ti and TiO2 Nanoparticles Producted by Electromagnetic Levitational Gas Condensation

The nanoparticles of Ti and TiO2 have attracted extensive research interest because of their diverse applications in, for instance, catalysis, energy conversion, pigment and cosmetic manufacturing and biomedical engineering. Through this project, a one-step bulk synthesis method of electromagnetic levitational gas condensation (ELGC) was utilized for the synthesis of monodispersed and crystalline Ti and TiO2 nanoparticles. Within the process, the Ti vapours ascending from the high temperature levitated droplet were condensed by an argon gas stream under atmospheric pressure. The TiO2 nanoparticles were produced by simultaneous injection of argon and oxygen into the reactor. The effects of flow rate of the condensing and oxidizing gases on the size and the size distribution of the nanoparticles were investigated. The particles were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and image analysis. The process parameters for the synthesis of the crystalline Ti and TiO2 nanoparticles were determined