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Cobalt ferrite (CoFe2O4)/barium titanate (BaTiO3) particulate composites exhibiting high magnetoelectric coefficients were synthesized from low-cost commercial precursors using mechanical ball milling followed by high-temperature annealing. CoFe2O4 (20 nm–50 nm) and either cubic or tetragonal BaTiO3 nanoparticle powders were used for the synthesis. It was found that utilizing a 50 nm cubic BaTiO3 powder as a precursor results in a composite with a magnetoelectric coupling coefficient value as high as 4.3 mV/Oe cm, which is comparable to those of chemically synthesized core–shell CoFe2O4–BaTiO3 nanoparticles. The microstructure of these composites is dramatically different from the composite synthesized using 200 nm tetragonal BaTiO3 powder. CoFe2O4 grains in the composite prepared using cubic BaTiO3 powder are larger (by at least an order of magnitude) and significantly better electrically insulated from each other by the surrounding BaTiO3 matrix, which results in a high electrical resistivity material. It is hypothesized that mechanical coupling between larger CoFe2O4 grains well embedded in a BaTiO3 matrix in combination with high electrical resistivity of the material enhances the observed magnetoelectric effect. 

Abstract The survival of patients with glioblastoma multiforme (GBM), the most common and invasive form of malignant brain tumors, remains poor despite advances in current treatment methods including surgery, radiotherapy, and chemotherapy. Minocycline is a semi‐synthetic tetracycline derivative that has been widely used as an antibiotic and more recently, it has been utilized as an antiangiogenic factor to inhibit tumorigenesis. The objective of this study was to investigate the utilization of electrospraying process to fabricate minocycline‐loaded poly(lactic‐co‐glycolic acid) (PLGA) microparticles with high drug loading and loading efficiency and to evaluate their ability to induce cell toxicity in human glioblastoma (i.e., U87‐MG) cells. The results from this study demonstrated that solvent mixture of dicholoromethane (DCM) and methanol is the optimal solvent combination for minocycline and larger amount of methanol (i.e., 70:30) resulted in a higher drug loading. All three solvent ratios of DCM:methanol tested produced microparticles that were both spherical and smooth, all in the micron size range. The electrosprayed microparticles were able to elicit a cytotoxic response in U87‐MG glioblastoma cells at a lower concentration of drug compared to the free drug. This work provides proof of concept to the hypothesis that electrosprayed minocycline‐loaded PLGA microparticles can be a promising agent for the treatment of GBM and could have potential application for cancer therapies.