Phospholipid-Coated Boronic Oxide Nanoparticles as Boron Agents for Boron Neutron Capture Therapy

Minimally invasive boron neutron capture therapy (BNCT) is an elegant approach for cancer treatment. The highly selective and efficient deliverability of boron agents to cancer cells is the key to maximizing the therapeutic benefits of BNCT. In addition, enhancement of the frequencies to achieve boron neutron capture reaction is also significant in improving therapeutic efficacy by providing a highly concentrated boron agent in each boron nanoparticle. As the density of the thermal neutron beam remains low, it is unable to induce high-efficiency cell destruction. Herein, we report phospholipid-coated boronic oxide nanoparticles as agents for BNCT that can provide a highly concentrated boron atom in each nanoparticle. The current system exhibited in vitro BNCT activity seven times higher than that of commercial boron agents. Furthermore, the system could penetrate cancer spheroids deeply, efficiently suppressing thermal neutron irradiation-induced growth.     

Covalent Targeting of Glutamate Cysteine Ligase to Inhibit Glutathione Synthesis**

Dysregulated oxidative stress plays a major role in cancer pathogenesis and some types of cancer cells are particularly vulnerable to inhibition of their cellular antioxidant capacity. Glutamate-cysteine ligase (GCL) is the first and rate-limiting step in the synthesis of the major cellular antioxidant glutathione (GSH). Developing a GCL inhibitor may be an attractive therapeutic strategy for certain cancer types that are particularly sensitive to oxidative stress. In this study, we reveal a cysteine-reactive ligand, EN25, that covalently targets an allosteric cysteine C114 on GCLM, the modifier subunit of GCL, and leads to inhibition of GCL activity. This interaction also leads to reduced cellular GSH levels and impaired cell viability in ARID1A-deficient cancer cells, which are particularly vulnerable to glutathione depletion, but not in ARID1A-positive cancer cells. Our studies uncover a novel potential ligandable site within GCLM that can be targeted to inhibit GSH synthesis in vulnerable cancer cell types.     

Coprecipitation synthesis of Ca14Al10Zn6O35:Mn4+ deep-red phosphor and silica-modified waterproofing ability

Ca₁₄Al₁₀Zn₆O₃₅:Mn⁴⁺ (CAZ:Mn) phosphor material, which shows deep-red luminescence, was synthesized by the coprecipitation (COP) method using a Na₂CO₃/NaOH solution as the precipitant. COP–CAZ:Mn phosphor exhibited a 2.1 times higher luminescence intensity than the corresponding phosphor prepared using the conventional solid-state reaction (SSR) method. This substantial increase in luminescence was mainly ascribed to the existence of a greater proportion of tetravalent manganese in COP–CAZ:Mn phosphor. Furthermore, COP–CAZ:Mn phosphor was modified with SiO₂ via hydrolysis of tetraethoxysilane (TEOS) to waterproof the compound because it is easily decomposed through hydrolysis under humid conditions. The SiO₂-modified CAZ:Mn phosphor maintained its crystal structure and high photoluminescence intensity after the water-resistance test. Therefore, waterproof CAZ:Mn phosphor with a high luminescence intensity was successfully discovered by utilizing the coprecipitation method and SiO₂ modification.