标题： 用于磁热疗的超顺磁性超级粒子：突破粒子尺寸限制 显示英文标题

标题： Superparamagnetic Superparticles for Magnetic Hyperthermia Therapy: Overcoming the Particle Size Limit

摘要： 氧化铁（例如，Fe$_3$O$_4$或 Fe$_2$O$_3$）纳米颗粒由于其超顺磁性、无毒性和可生物降解性，是多种生物医学应用的有前途的候选材料，从磁热疗到药物输送和生物检测。 虽然小尺寸（低于临界尺寸，约20 nm）的颗粒在室温下表现出超顺磁行为，但这些颗粒容易渗透到身体的高敏感区域，如血脑屏障（BBB），导致不良影响。 此外，这些颗粒具有较高的滞留概率，可能导致基因毒性和生化毒性。 增加颗粒尺寸是解决这些问题的一种方法，但同时也会抑制超顺磁性。 我们通过合成由多个10至15 nm大小的纳米晶体组成的独特多晶氧化铁纳米颗粒，同时将颗粒尺寸调节为160至400 nm，克服了这一尺寸限制。 这些所谓的超级颗粒保留了超顺磁特性，并表现出优异的磁热疗响应。 在0.5 mg/mL的低浓度下，比吸收率（SAR）超过250 W/g（HAC = 800 Oe，f = 310 kHz），表明它们在癌症治疗中具有最小剂量的能力。 我们的研究强调了具有超顺磁特性的尺寸可调多晶氧化铁超级颗粒在先进生物医学应用和传感技术中的潜力。 显示英文摘要

摘要： Iron oxide (e.g., Fe$_3$O$_4$ or Fe$_2$O$_3$) nanoparticles are promising candidates for a variety of biomedical applications ranging from magnetic hyperthermia therapy to drug delivery and bio-detection, due to their superparamagnetism, non-toxicity, and biodegradability. While particles of small size (below a critical size, ~20 nm) display superparamagnetic behavior at room temperature, these particles tend to penetrate highly sensitive areas of the body such as the Blood-Brain Barrier (BBB), leading to undesired effects. In addition, these particles possess a high probability of retention, which can lead to genotoxicity and biochemical toxicity. Increasing particle size is a means for addressing these problems but also suppresses the superparamagnetism. We have overcome this particle size limit by synthesizing unique polycrystalline iron oxide nanoparticles composed of multiple nanocrystals of 10 to 15 nm size while tuning particle size from 160 to 400 nm. These so-called superparticles preserve superparamagnetic characteristics and exhibit excellent hyperthermia responses. The specific absorption rates (SAR) exceed 250 W/g (HAC = 800 Oe, f = 310 kHz) at a low concentration of 0.5 mg/mL, indicating their capability in cancer treatment with minimum dose. Our study underscores the potential of size-tunable polycrystalline iron oxide superparticles with superparamagnetic properties for advanced biomedical applications and sensing technologies.