Synthesis and Evaluation of Nano-antioxidants for Medical Applications

描述(申请人提供)：据报道，抗氧化剂有益于预防多种人类疾病，包括癌症、心血管疾病、神经退行性疾病、肺病和慢性病。常用的抗氧化剂是小分子化合物，具有中和自由基、破坏潜在的自由基形成物质、增强免疫系统和表现出其他有益于人类健康的生物活性的能力。人们对分子量在数千左右的大分子抗氧化剂知之甚少。更具体地说，树枝状抗氧化剂的生物学效应以前还没有报道过。这一应用涉及到抗氧化剂树状大分子的合成，该树状大分子由多个抗氧化剂单元组成，以树状方式相互连接，从而有效地清除自由基。纳米抗氧剂分子将以二羟基苯甲醛和丙叉胺支化单元为基础，以叠加的方式合成，得到定义明确和精确的树枝状大分子。据推测，这种独特的抗氧化剂结构将显示出协同效应，并显示出一些有趣和有益的性质，如改善水的溶解性和稳定性，增强清除自由基的能力。人们还认为，这些纳米粒子将与生物分子有更强的相互作用，因此比小分子抗氧化剂更能保护生物免受自由基损伤。这些新型纳米材料将通过一系列化学和生物分析技术进行表征，包括聚丙烯酰胺凝胶电泳法、高效液相色谱法、光谱学和质谱仪。它们的抗氧化效力将通过电子自旋共振和光谱分析进行测量，并与对照组进行比较，例如单体(积木)和常见的抗氧化剂，如维生素C和E。抗氧化剂树枝状大分子保护DNA、脂质、蛋白质和红细胞的能力将在体外自由基生成系统中测定，并与小分子抗氧化剂进行比较。DNA链断裂将通过琼脂糖凝胶电泳法进行测定。蛋白质损伤将通过荧光光谱、反相高效液相色谱、尺寸排除层析和凝胶电泳进行监测。脂质过氧化反应将通过紫外分光光度法监测二烯的形成来测量，而细胞损伤将通过红细胞溶血来评估。这些研究应该为纳米抗氧化剂对生物分子和细胞的保护作用提供宝贵的数据。此外，所提出的抗氧化剂树状大分子将为制备用于检测、诊断和治疗疾病的多功能纳米设备提供一个独特的平台。与公共健康相关：这项应用将涉及抗氧化剂树枝状大分子的合成，并研究它们清除自由基的能力以及它们对生物分子和细胞的影响。这项研究的结果将有助于纳米抗氧化剂用于预防、检测、诊断和治疗与氧化应激密切相关的人类疾病，包括癌症、心血管疾病以及慢性炎症性和神经退行性疾病。

DESCRIPTION (provided by applicant): Antioxidants have been reported to be beneficial for prevention of a variety of human diseases including cancer and cardiovascular, neurodegenerative, pulmonary and chronic ailments. Commonly available antioxidants are small molecular weight compounds that have the ability to neutralize free radicals, destroy potential radical forming substances, boost the immune system and exhibit other biological activities that are beneficial to human health. Little is known about large antioxidant molecules with molecular weights in the thousands. More specifically, the biological effects of dendritic forms of antioxidants have not been reported before. This application involves the synthesis of antioxidant dendrimers composed of numerous units of antioxidants connected to one another in a tree like fashion so that they can effectively scavenge free radicals. The nano-antioxidant molecules will be synthesized with dihydroxybenzaldehyde building blocks and propargylamine branching units in a reiterative manner to give well-defined and precise dendrimers. It is hypothesized that this unique antioxidant architecture will display cooperative effects and reveal some interesting and beneficial properties such as improved aqueous solubility and stability and enhanced radical scavenging potency. It is also believed that these nano-particles will have stronger interactions with biomolecules and therefore be better protectants than small molecule antioxidants against free radical damage. These novel nano-materials will be characterized by a number of chemical and bio-analytical techniques including polyacrylamide gel electrophoresis, HPLC, spectroscopy and mass spectrometry. Their antioxidant potency will be measured with electron spin resonance and spectroscopic assays and compared to controls, such as their monomeric counterparts (building block) and common antioxidants like vitamins C and E. The ability of the antioxidant dendrimers to protect DNA, lipids, proteins and red blood cells will be determined in a free radical generating system in vitro and compared to small molecule antioxidants. DNA strand breakage will be determined by agarose gel electrophoresis. Protein damage will be monitored by fluorescence spectroscopy, reversed phase HPLC, size exclusion chromatography, and gel electrophoresis. Lipid peroxidation will be measured by monitoring diene formation with ultraviolet spectrophotometry while cell damage will be evaluated by red blood cell hemolysis. These studies should provide invaluable data towards the protective effects of nano-antioxidants on biomolecules and cells. In addition, the proposed antioxidant dendrimer will provide a unique platform for preparing multifunctional nano-devices for detection, diagnosis and treatment of diseases. PUBLIC HEALTH RELEVANCE: This application will involve the synthesis of antioxidant dendrimers and investigate their free radical scavenging potency as well as their effects on biomolecules and cells. Results of this study will benefit the use of nano-antioxidants for prevention, detection, diagnosis and treatment of human diseases that have a strong association with oxidative stress including cancer, cardiovascular diseases, and chronic inflammatory and neurodegenerative diseases.