Cylindrical polymer brushes as luminescent probes for bioimaging

700万加拿大人生活在农村或偏远社区，他们的总体健康状况一直比城市人口差。缺乏医疗保健专业人员以及距离医疗保健设施较远都是造成这种差异的主要原因，因为18%的加拿大农村人口只有8%的执业医生为他们提供服务。在卫生保健资源有限的地方，需要既便宜又容易获得的诊断工具。智能手机现在无处不在，内置光源，摄像头和网络连接是便携式生物分析和成像的理想选择。这些测定需要具有足够亮度的发光探针，以便用智能手机相机可见。这可以通过使用纳米颗粒来实现，这些纳米颗粒将数百到数千个发光染料分子整合到单个纳米级物体中，从而产生智能手机可以检测到的单点亮度。聚合物点（或Pdot）是一类这样的纳米颗粒，由> 50重量%或体积%的发光聚合物组成，被亲水性外部包围以使它们可溶于水。我们在UBC的研究小组开发了用于生物分析和成像的多功能Pdot探针。为了将这些技术转化为应用，我们现在必须了解纳米颗粒的形状和刚性如何影响Pdot在体内的循环时间和细胞相互作用。悉尼大学的Markus Müllner教授最近表明，圆柱形聚合物刷（CPB）-与中心骨架结合的长链聚合物-可以表现出较长的循环时间，改善细胞渗透和细胞内的可调定位。与Müllner教授合作，该项目将开发具有CPB形态的发光Pdot，并将研究它们在多细胞肿瘤球体内的渗透动力学和成像能力。该项目将帮助我们首次了解纳米颗粒形状如何影响Pdot在细胞和肿瘤模拟物中的成像性能。

7 million Canadians live in rural or remote communities, and consistently show poorer overall health outcomes than urban populations. A lack of healthcare professionals as well as longer distances to healthcare facilities are both major drivers of this discrepancy, as the 18% of rural Canadians are served by only 8% of the practicing physicians in Canada. Where healthcare resources are limited, diagnostic tools are needed that are both inexpensive and readily available. Smartphones are now ubiquitous, and with built-in light sources, cameras, and network connectivity are ideal for portable bioanalysis and imaging. These assays require luminescent probes with sufficient brightness to be visible with a smartphone camera. This can be achieved using nanoparticles that incorporate hundreds to thousands of luminescent dye molecules into a single nanoscale object, creating single points of brightness that a smartphone can detect. Polymer dots (or Pdots) are one such class of nanoparticle, consisting of >50% of luminescent polymer by weight or volume, surrounded with a hydrophilic exterior to render them soluble in water. Our research group at UBC develops multifunctional Pdot probes for bioanalysis and imaging.To translate these technologies to application, we must now understand how nanoparticle shape and rigidity impact the circulation time and cellular interactions of Pdots in vivo. Prof. Markus Müllner at the University of Sydney has recently shown that cylindrical polymer brushes (CPBs) - long chains of polymers bonded to a central backbone - can exhibit long circulation times, improved cell penetration, and tunable localization within cells. In collaboration with Prof. Müllner, this project will develop luminescent Pdots with a CPB morphology, and will study their penetration kinetics and imaging capabilities within multicellular tumour spheroids. This project will help us understand how nanoparticle shape affects Pdot performance in imaging for the first time, in both cells and tumour mimics.