Materials governed by lightAugust 04, 2017
Hybrid materials are those that combine components of differing origins (organic and inorganic) in order to obtain materials different from conventional ones and which display new or improved properties owing to the synergistic effect between their components. Rebeca Sola, a researcher in the Department of Physical Chemistry in the UPV/EHU's Faculty of Science and Technology, has developed and exhaustively characterised hybrid, photoactive materials --which respond differently when exposed to excitation light-- which could have applications in highly different fields, such as optics and biomedicine. In the research conducted in this department, hybrid materials were obtained, among other things, by incorporating fluorescent dyes, which are routinely used in solution, into channelled inorganic structures. These materials firstly give the dye protection, thus rendering it more stable against degradation and increasing the useful service life of the devices that incorporate them, and secondly, they provide the system with rigidity, which is interesting as this has the potential to increase the photophysical properties of the organic hosts (the dyes).
As the researcher explained, "highly fluorescent materials in which the dyes are found to be ordered were obtained, thus providing a highly anisotropic response to the linearly polarized light". In other words, materials that respond differently depending on the direction of the polarization of the incident light. Furthermore, it "is fairly straightforward," to synthesise these materials said Sola. "Crystalline structures in which the dye has already been occluded inside are obtained without any need to apply a diffusion process to insert the dye into the crystal."
Various optical applications
The researcher has thus obtained materials with a very wide range of optical properties. "Of great interest are those in which there is an artificial antenna effect with the ordering of the different kinds of dye and a unidirectional energy transfer," she said. This is translated into particles with multi-coloured fluorescence, which are capable of picking up the energy from light at one end and transferring it to the opposite end, which could be of interest with respect to integrating them into solar cells.
Another of the materials obtained is a solid material that emits delayed fluorescence: instead of the fluorescence of the system turning off as soon as the excitation source is removed, as is usually the case, it persists for tenths of a second and is perfectly visible to the naked eye. "This kind of technology could be of interest in LED technologies," she explained. And materials capable of transforming incident laser light into light with double the amount of energy were also obtained.
These materials not only allow the incorporation of a single dye into the inorganic structure, various dyes can also be simultaneously encapsulated. "With two dyes whose response is complementary, we have obtained fluorescent particles that change colour depending on the light polarization, and change from a blue fluorescent emission to a green one," added Sola. What is more, it is a reversible, reproducible process". By incorporating a third, red-emission dye in the correct proportion, a white-light emitting system was also obtained, "once again of interest for illumination systems," she concluded.
White-light emitters were also obtained by adding small organic molecules to certain frameworks of metal ions and organic compounds known as MOFs (Metal Organic Frameworks); ambient-temperature phosphorescence was also obtained with them. "Phosphorescence is an emission process that routinely calls for very low temperatures to prevent the phosphorescent light from deactivating," explained Sola.
Leap to biomedicine
The researchers have shown that hybrid materials may have applications in other fields, such as biomedicine. To do this, they used photosensitising substances suitable for photodynamic therapy. These are materials that combine organic and inorganic fragments to produce a kind of oxygen capable of causing the death of certain cells following excitation by light. Photodynamic therapy is a procedure used in dermatology, for example, to treat a range of skin diseases and even for different types of cancer. Materials that not only generate this type of cytotoxic oxygen but which are also fluorescent have been obtained. And "that makes them very useful for bioimaging as well," added the researcher. "The phototoxic action of these compounds is being explored by means of experiments in in-vitro cell cultures, and although the results are promising, we are still in the early phases of the study," she concluded.
This study is part of the PhD thesis by Rebeca Sola-Llano (Barakaldo, 1989), entitled 'Synergism between organic and inorganic moieties: in the search of new hybrid materials for optics and biomedicine'. Her supervisors were the Ramón y Cajal researcher Virginia Martínez-Martínez and the UPV/EHU professor Iñigo López-Arbeloa. Research groups at the Institute of Catalysis and Petrochemistry in Madrid, the Complutense University of Madrid, the University of Kyoto, the Katholieke Universiteit of Leuven and the Autonomous University of Madrid collaborated in this thesis.
M. J. Ortiz, E. Palao, R. Sola-Llano, A. Tabero, H. Manzano, A. R Agarrabeitia, A. Villanueva, I. López-Arbeloa, V. Martinez-Martinez. 'AcetylacetonateBODIPY?biscyclometalated Iridium(III) complexes: Effective strategy towards smarter fluorescent-photosensitizer agents' (2017). Chem. Eur. J. 10.1002/chem.201701347
University of the Basque Country
Related Photodynamic Therapy Articles:
Researchers presenting a preclinical study at the 2017 Annual Meeting of the Society of Nuclear Medicine and Molecular Imaging (SNMMI) demonstrated the efficacy and optimal dose for targeted photodynamic therapy (tPDT) to treat prostate cancer before and during surgery.
Massachusetts General Hospital investigators report finding finding how appropriately timed radiation therapy can significantly improve the delivery of cancer nanomedicines by attracting macrophages to tumor blood vessels, which results in a transient 'burst' of nanoencapsulated drugs from capillaries into the tumor.
UMass Medical School scientist Gang Han, PhD, and his team have designed a new class of molecules used in photodynamic therapy that are able to direct lamp light deep into tissue to kill cancer tumors.
Physicists at The University of Texas at Arlington have shown that using microwaves to activate photosensitive nanoparticles produces tissue-heating effects that ultimately lead to cell death within solid tumors.
The expression dog is man's best friend might have more weight in the case of first-year university students suffering from homesickness, according to a new UBC study.
Key leaders in the field of cellular therapy will highlight new applications to potentially cure patients with blood diseases and infections on the occasion of the 5th Cell Therapy Day.
A nanoparticle drug-delivery system that combines two complementary types of anticancer treatment could improve outcomes for patients with pancreatic cancer and other highly treatment-resistant tumors while decreasing toxicity.
Researchers have made a significant advance in the use of photodynamic therapy to combat ovarian cancer in laboratory animals, using a combination of techniques that achieved complete cancer cell elimination with no regrowth of tumors.
Among patients with a first episode of pulmonary embolism (the obstruction of the pulmonary artery or a branch of it leading to the lungs by a blood clot) who received six months of anticoagulant treatment, an additional 18 months of treatment with warfarin reduced the risk of additional blood clots and major bleeding, however, the benefit was not maintained after discontinuation of anticoagulation therapy, according to a study in the July 7 issue of JAMA.
BioMed Central is pleased to partner with the Japanese Society for Dialysis Therapy in publishing the open-access journal Renal Replacement Therapy.
Related Photodynamic Therapy Reading:
Photodynamic Therapy: From Theory to Application
by Mahmoud H. Abdel-Kader (Editor)
Photodynamic Therapy: From Theory to Application brings attention to an exceptional treatment strategy, which until now has not achieved the recognition and breadth of applications it deserves. The authors, all experts and pioneers in their field, discuss the history and basic principles of PDT, as well as the fundamentals of the theory, methods, and instrumentation of clinical diagnosis and treatment of cancer. Non-oncological applications such as the use of PDT in control of parasites and noxious insects are also discussed. This book serves as a standard reference for researchers and... View Details
Photodynamic Therapy of Diseases of the Head and Neck
by Merrill A. Biel (Author)
This authoritative text presents the background, methodology and outcomes for Photodynamic Therapy (PDT) treatment of diseases of the head and neck. The author, an expert and pioneer in this field, discusses the indications for PDT treatment with their advantages and pitfalls. As PDT is an approved therapy for treatment of head and neck cancers in many countries in the world, this text provides the clinician and basic researcher with an understanding of PDT and how to successfully employ it for the successful treatment of head and neck cancers. This comprehensive book is unique in that no... View Details
Photodynamic Therapy in Dermatology
by Michael H. Gold (Editor)
Photodynamic therapy is a proven effective treatment of actinically damaged skin cells, nonmelanoma skin cancers, and acne and other pilosebaceous conditions. As an agent for general facial rejuvenatin it has untapped potential. The current state of PDT therapy and future applications are discussed in detail in this exciting new volume. Throughout, the focus is on evidence-based clinical uses of PDT, including pretreatment regimens, avoidance and management of complications, and posttreatment suggestions. View Details
Photodynamic Therapy: Basic Principles and Clinical Applications
by Henderson (Author)
Covering all aspects of photodynamic therapy, 70 expert contributors from the fields of photochemistry, photobiology, photophysics, pharmacology, oncology and surgery, provide multidisciplinary discussions on photodynamic therapy - a rapidly-developing approach to the treatment of solid tumours.;Photodynamic Therapy: Basic Principles and Clinical Applications describes the molecular and cellular effects of photodynamic treatment; elucidates the complex events leading to photodynamics tissue destruction, particularly vascular and inflammatory responses; discusses the principles of light... View Details
Photodynamic Therapy in Veterinary Medicine: From Basics to Clinical Practice
by Fábio Parra Sellera (Editor), Cristiane Lassálvia Nascimento (Editor), Martha Simões Ribeiro (Editor)
This pioneering book offers an introduction to photodynamic therapy, a promising new approach in the treatment of complex diseases like cancer and microbial infections in animals. Addressing all aspects, ranging from basics to clinical practice, it presents the history and fundamentals of photodynamic therapy for non-experts. It includes a collection of basic and clinical studies in cancer and infectious diseases, as well as illustrations of successful treatment procedures and future perspectives and innovative applications involving nanotechnology and advanced drug delivery. This valuable... View Details
Cosmetic Photodynamic Therapy (Aesthetic Dermatology, Vol. 3)
by M.H. Gold (Editor), D.J. Goldberg (Editor)
Photodynamic Therapy (PDT) has become an important treatment modality in medical practice. New and exciting applications continue to emerge and the future of PDT looks brighter and brighter. Dermatologists and other health professionals around the world rely on its therapeutic effect for the treatment of actinic keratoses, non-melanoma skin cancers, acne vulgaris, and various other dermatologic conditions. In this comprehensive yet concise book, world-renowned experts showcase all of the common, everyday uses of PDT in dermatologic offices. They also examine how this beneficial therapy can be... View Details
Handbook of Photodynamic Therapy: Updates on Recent Applications of Porphyrin-Based Compounds
by Ravindra K Pandey (Editor), Thomas J Dougherty (Editor), David Kessel (Editor)
The book, written for a general educated public, compares the most important elements of the human nervous system to the corresponding capacities of robots. Crucial are the areas of activities for which the constraints limiting human and robot performances are much different. Those areas offer opportunities for synergies.The book argues that we now understand mechanisms for emotional feelings in the human brain so well that we will be able to program robots to act as though they also have emotion. Written in a clear and open fashion by an expert neuroscientist, the book will appeal to... View Details
Advances in Photodynamic Therapy: Basic, Translational and Clinical (Engineering in Medicine & Biology)
by Michael R. Hamblin (Editor), Pawel Mroz (Editor)
With today's focus on targeted and minimally invasive therapies, photodynamic therapy (PDT) is now being studied and used to combat many disease states and to investigate critical biological questions. This groundbreaking resource brings practitioners and researchers the latest advances in photodynamic therapy and offers a solid understanding of the design, delivery and dosimetry of the three basic ingredients of PDT - photosensitizers, light and oxygen. The book covers novel areas of mechanistic and innovative translational approaches. Moreover, it presents an overview of the important... View Details
Photodynamic Therapy: Methods and Protocols (Methods in Molecular Biology)
by Charles J. Gomer (Editor)
Biological interactions of visible light with photosensitizers have been studied for over a century while controlled clinical applications of light and photosensitizers to treat solid tumors, known as photodynamic therapy, have been evolving since the mid 1970’s. In Photodynamic Therapy: Methods and Protocols, leading PDT scientists and clinicians provide the first comprehensive collection of methods and protocols specifically related to relevant mechanistic, dosimetric, preclinical, and clinical procedures used in current PDT research. Reflecting the growing number of studies... View Details