The Role of Inorganic Photosensitisers in Radiation Sensitive Films for Cancer Treatment

商业上重要的双乙炔被用来在实用的化学传感器、生物传感器和剂量计中提供比色变化。特别重要的是放射学和放射治疗胶片，例如用于监测癌症放射治疗期间的辐射靶向和剂量的Gafchroic胶片。镓铬薄膜还可用于无损检测(NDT)应用，即对物品(如管道、盒子等)进行快速X射线检测。可能是必不可少的。Gafchroic薄膜是基于辐射诱导的光聚合，作为涂覆在聚酯基材上的复杂光活性层的一部分的亲脂性双乙炔。调节活性成分的光响应及其与剂量相关的转化率对于辐射剂量学应用具有相当大的兴趣。特别是，无机光敏剂在薄膜中的作用在作用模式和化学形态方面都知之甚少。现有的薄膜成分，如铋和氧化铝，似乎在激活和控制薄膜反应方面发挥了关键作用，但它们与二乙炔相互作用的方式尚不清楚。该项目旨在自下而上地了解铋和铝氧化物的膜内配位化学，以及这些无机添加剂在组织双乙炔的固态结构中所起的作用，以促进辐射吸收和导致可控的、众所周知的拓扑定向光聚合。该项目将涉及铋和铝的二乙炔羧酸盐络合物的合成和结构表征，研究该体系在薄膜中的化学形态，对局部pH等因素的依赖，以及由控制固态二氢键光聚合的拓扑化学参数指导的结构-敏感性关系的推导。该项目还将探索新的光敏剂，如铋钒氧化物，并绘制钒配位产生的结构-性质关系图。该项目将在很大程度上依赖于单晶和粉末X射线衍射方法，在以前的工作中，令人惊讶的是，尽管这些类型的双乙炔具有表面活性物质的性质，但对它们进行详细的X射线结构工作是可能的。学生将接触到合成配位化学以及多种结晶方法。学生将学习使用广泛的分析技术，如X射线粉末衍射、单晶衍射、晶体和非晶态材料的热分析、核磁共振光谱分析(特别是固态核磁共振)，以及了解晶体堆积和结构-性能关系的方法。学生还将使用热阶段偏振光学显微镜、扫描电子显微镜和透射电子显微镜来分析粒子的形状和热行为。学生将受益于与阿什兰的奥萨马·穆萨博士(首席技术官)和大卫·胡德博士领导的工业监督小组每月举行的会议和演讲。他们将接触到产品开发工作流程和工业中采用的方法，以了解固体形式、复杂配方和光反应性。他们将准备定期的技术报告和幻灯片包进行演示，因此将学习更柔和的沟通技能，演示具有冲击力，并接触到化学科学家以外的更广泛的受众，以展示他们研究的价值。他们将参加国家培训课程，如BCA结晶学和粉末衍射学校，并将在RSC MASC等会议上介绍他们的工作。

The commercially important diacetylenes are used to provide a colourimetric change in practical chemosensors, biosensors, and dosimeters. Of particular importance are radiology and radiotherapy films such as Gafchromic which are used, for example, to monitor radiation targeting and dosage during cancer radiotherapy. Gafchromic films can also be utilized in non-destructive testing (NDT) applications where rapid X-ray inspection of articles (e.g. pipes, boxes etc.) can be essential. Gafchromic films are based on radiation-induced photopolymerization of a lipophilic diacetylene as part of a complex photoactive layer coated on a polyester base. Tuning of the photoresponse of the active ingredient and its dosage dependent conversion is of considerable interest for radiation dosimetry applications. In particular, the role of inorganic photosensitizers within the film is poorly understood both in terms of mode of action and chemical speciation. Existing film components such as bismuth and aluminium oxides seem to play a key role in activating and controlling film response but the way in which they interact with the diacetylene is unknown. This project aims to derive a bottom-up understanding of the in-film coordination chemistry of bismuth and aluminium oxides and the role these inorganic additives have in organizing the solid state structure of diacetylenes in order to promote radiation absorption and result in controlled, well-understood topotactic photopolymerization. The project will involve the synthesis and structural characterization of diacetylene carboxylate complexes of bismuth and aluminium, study of the chemical speciation of this system in films, dependence on factors such as local pH and derivation of structure-sensitivity relationships guided by the topochemical parameters governing solid state dialkyne photopolymerization. The project will also explore new photosensitisers such as bismuth vanadium oxides and chart the structure-property relationships arising from vanadium coordination. The project will rely heavily on single crystal and powder X-ray diffraction methods and in previous work it has been surprisingly possible to undertake detailed X-ray structural work on these types of diacetylenes despite their surfactant-like nature. the student will be exposed to synthetic coordination chemistry as well as multiple crystallization approaches. The student will learn to use a broad range of analytical techniques such as X-ray powder diffraction, single crystal diffraction, thermal analysis of crystalline & amorphous materials, NMR spectroscopy (particularly solid state NMR), and approaches to understand crystal packing and structure-property relationships. The student will also use hot stage polarized optical microscopy, SEM and TEM in analysing particle shape and thermal behaviour. The student will benefit from monthly meetings and presentations with the industrial supervisory team led by Dr. Osama Musa (Chief Technology Officer) and Dr. David Hood at Ashland. They will be exposed to product development workflows and approaches taken in industry to understand solid forms, complex formulations and photoreactivity. They will prepare regular technical reports and slide packs to present and so will learn softer communication skills, presenting with impact and reaching out to a wider audience beyond chemical scientists to demonstrate the value of their research. They will take part in national training courses such as the BCA Crystallography and Powder Diffraction Schools and will present their work at Conferences such as the RSC MASC.