35 research outputs found
Biomagnetic of Apatite-Coated Cobalt Ferrite: A Core–Shell Particle for Protein Adsorption and pH-Controlled Release
Magnetic nanoparticle composite with a cobalt ferrite (CoFe2O4, (CF)) core and an apatite (Ap) coating was synthesized using a biomineralization process in which a modified simulated body fluid (1.5SBF) solution is the source of the calcium phosphate for the apatite formation. The core–shell structure formed after the citric acid–stabilized cobalt ferrite (CFCA) particles were incubated in the 1.5 SBF solution for 1 week. The mean particle size of CFCA-Ap is about 750 nm. A saturation magnetization of 15.56 emug-1 and a coercivity of 1808.5 Oe were observed for the CFCA-Ap obtained. Bovine serum albumin (BSA) was used as the model protein to study the adsorption and release of the proteins by the CFCA-Ap particles. The protein adsorption by the CFCA-Ap particles followed a more typical Freundlich than Langmuir adsorption isotherm. The BSA release as a function of time became less rapid as the CFCA-Ap particles were immersed in higher pH solution, thus indicating that the BSA release is dependent on the local pH
Minimally required heat doses for various tumour sizes in induction heating cancer therapy determined by computer simulation using experimental data
Achieving convergence-free routing using failure-carrying packets
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Shrinkage and colour in the production of micro-sized PDMS particles for microfluidic applications
Polydimethylsiloxane (PDMS), due to its remarkable properties, is a suitable polymer for the
production of microparticles with industrial and medical applications. The micro-sized PDMS
liquid droplets suffer a pronounced shrinkage while curing to turn into solid particles. In this article,
we report the calibration of the shrinkage phenomenon in the production of PDMS microparticles.
Our results show that this shrinkage does not depend on the amount of curing agent in the PDMS
precursor or on the addition of micro/nanoparticles to the mixture, but on the surface effects due
to the relatively large droplet surface-to-volume ratio. Moreover, we have also investigated the
addition of colour to the particles to improve their visualization/detection. The addition of colour
by using pigments enhances the visualization of the contours of the PDMS microparticles, and
reveals the capability of this technique to microencapsulate micro/nanoparticles in PDMS spheres
with diameters below 10 ÎĽm. We demonstrate that the technique used in this work is able to work
with a wide range of viscosities obtaining an acceptable degree of monodispersityFundação para a Ciência e a Tecnologia (FCT), COMPETE2020 through projects UID/EMS/00532/2013, UID/EMS/04077/2013, POCI-01-0145-FEDER-016861 (with associated reference PTDC/QEQ-FTT/4287/2014) and fellowships SFRH/BD/89077/2012 and SFRH/BSAB/135419/2017. Partial support from the spanish Ministry of Science and Education (grant no. DPI2016-78887), Gobierno de Extremadura (grant no. GR10047), and "la Caixa" Foundation (predoctoral grant) is gratefully acknowledged to