Porphyrin-nanosensor conjugates. New tools for the measurement of intracellular response to reactive oxygen species

Abstract

Reactive oxygen species (ROS) have for some time been implicated in the onset and progression of medical conditions including cancer, ageing, heart disease and Alzheimer's disease. Recently, it has been postulated that ROS play a much more subtle role in intracellular signalling mechanisms as second messengers. Given the importance of these species in influencing cellular processes, it is surprising that tools for studying intracellular levels of ROS are extremely limited and devices for studying the cells' response to internally generated ROS are virtually non-existent. In order to study the response of cells to intracellular ROS we have designed a nano-scale device that can both generate ROS and simultaneously monitor the cells' reaction as a function of changes in the important signalling ion, calcium. Here we report the synthesis, characterisation, and calibration of a new ROS nano-probe and demonstrate its ability to detect cellular response to elevated levels of intracellular ROS.

Unique Diagnostic and Therapeutic Roles of Porphyrins and Phthalocyanines in Photodynamic Therapy, Imaging and Theranostics

“…Research into improved photosensitisers saw the development of second-generation photosensitisers, including Verteporfin ® (Visudyne ® ) and third-generation photosensitisers focused on targeting strategies, such as antibody-directed photosensitisers and photosensitiser-loaded nanocarriers 4, 14, 24, 26, 32, 64, 65. Combined diagnostic and therapeutic modalities gave begun to emerge creating theranostic tools for use in identifying (imaging) and treating diseased states: are these the next generation of pdt agents 28, 66-69? The ability to “switch on” a cytotoxic effect, and combine photosensitisers with imaging modalities such as magnetic resonance imaging (MRI) and radioimaging, makes pdt particularly attractive as the therapeutic partner in theranostic agents.…”

“…Nanospecies (NS) of many different compositions and for a variety of applications have been described in the literature 66, 328-381. These species are generally, but not exclusively, synthesised from polymers and due to their minute size are comparable to biological molecules 325, 347, 367-369.…”

“…These species are generally, but not exclusively, synthesised from polymers and due to their minute size are comparable to biological molecules 325, 347, 367-369. Through the ability to fine-tune both their physical and chemical properties, a range of versatile NS can be synthesised with varying sizes, compositions and surface chemistries 66, 67, 68, 326, 332, 334, 336, 342, 344, 346, 347, 349, 356, 364, 368, 382-387. The ability to create species with nanometre dimensions brings with it the potential to bring about life-changing advances in both science and medicine.…”

Influence of phenyl-attached substituents on the vibrational and electronic spectra of meso-tetraphenylporphyrin: A DFT study

“…From this part of the result, it can be commented that the overall structures of the porphine centers remain undisturbed as the substituents are introduced to the phenyl rings. Only FB4 could be closest to being "disturbed" 6 as it shows the largest deviation in C β -C β -C α -C m and N-C α -C m -C 1 dihedral angles. However, the degree of deviation is still minimal.…”

“…This has inspired many studies in the pursuits of its applications, such as nonlinear optical materials [1][2], photodynamic therapy [3][4], nanosensors [5][6] and photovoltaic devices. The last has been gaining more and more spotlight in recent years after the early-2000s breakthrough of dye-sensitized solar cells (DSSCs) [7][8][9][10][11][12][13][14], a decade after Grätzel's group proposed a novel architecture of sunlight harvesting panels consisting of a sensitizing ruthenium-based dye and the semiconductor electrode [15].…”