SBBN has been focused actions for integrating multidisciplinary teams. New rationale is required to use available technologies, which intersect among imaging, electrochemistry, biophotonics, nanotechnologies and combinatorial molecules. The SBBN events are opportunities to change experience about our common impact problems, as Bioethics, animal experimentation and alternative methods, biosafety, radiation protection, drug registration, interaction with research ethics committees, among others. Themes that actually have developed at isolated way may be integrated. The current frontiers in Biological Sciences demand an interface among disciplines of Biology, Chemistry and Physics to achieve new paradigms on applied ionizing and non-ionizing as well as nanobiotechnologies, looking for individualized Medicine.
Radiobiology and Biodosimetry
The biophysical understanding of cellular damage induced by ionizing radiations is of great interest, considering the increasing of medical procedures and industrial applications, intercontinental flies and space explorations, some nuclear power plants accidents and incidents and, most recently, the threats against the nuclear, biological and chemical terrorism. Radiological accidents may occur in all these practices and the scientific understanding is widespread by the scientific societies.
In high doses in Radiotherapy, syndromes of chromosome fragility may be manifested when exacerbated adverse effects occur after radiotherapy hypersensitivity. Cell-to-cell variability of cell damage, effects of low and high doses or dose rates, possible adaptation phenomenon to low doses versus the linear model in which even small doses has a potential hazard, are some research presented.
All these topics involve experimental radiobiology, simulation of DNA damage induced by radiations, blood samples from patients or victims of nuclear accidents. Effects of ionizing on brain activity, on chromosome aberrations, micronuclei or DNA fragmentation, on gene and protein expressions, are some of the biological endpoints discussed. In therapies, the tissue response to high radiation doses generally follows a characteristic pattern determined by the radiosensitivity in the cell population involved, radiation quality and temporal pattern of injury development and repair.
Some drugs used as radiosensitizers target physiological differences characteristic of each tumour, mainly the hypoxia associated with radioresistance. The three major approaches involve increased radiosensitivity of tumour tissue, reversion of radiation resistance in tumour tissue and increased radioresistance in healthy tissue. Some substances, including nanoparticles, have played a key role or presented good perspectives for a higher effectiveness of radiotherapy.
Medical applications of ionizing radiation
Ionizing radiations have been valuable for diagnosis and treatment, such as sealed sources for radiotherapy (brachytherapy) or non-sealed (radiopharmaceuticals) for molecular imaging. Techniques, such as single positron emission tomography (SPECT) and photon emission tomography (PET), allow the acquisition of high definition images from various organs. However, the development of radiopharmaceuticals is a difficult and multidisciplinary task. In recent years, nanobiotechnology has added new possibilities for improving physical and chemical characteristics of radioactive materials. To evaluate the safety and efficacy of products, several methods have been improved through preclinical and clinical studies and quality assurance protocols. In preclinical studies, positron emission microtomography (microPET) technology for animal models of neuropathologies has leveraged research on neurodegenerative diseases.
Molecular imaging and Radiopharmacy
Three-dimensional radiotherapy planning requires using of several imaging methodologies, including hybrid images PET/CT or PET/RM, which have added pathophysiological data from tumors and imaging reconstruction techniques with great clinical impact. Gamma radiation or positron emitting particle provides image quantification of blood flow in different organs or the detection of specific receptors by radiolabeled probes bindings. Using alfa or beta emitting particles, radiolabeled molecules are capable to treat cancer disease.
Research in Radiopharmacy focuses the development of drugs and molecules labeled with radioactive isotopes (probes). Radiopharmacy has a multidisciplinary approach, compressing itself by organic and inorganic chemist, in charge of develop new molecules; radiochemist and radiopharmacist, in charge to develop radiolabeling methods for research and clinical applications purposes; pharmacist and physicist to develop pharmacokinetics studies and develop image acquisition and processing protocols; biologist and biomedical scientists, to validate action mechanism of drug or radiolabeled probe. Furthermore, it is strongly connected with Physics, mainly associated with the production of radioisotopes in nuclear reactors and cyclotrons, and with Nuclear Medicine, for use of approved probes for diseases diagnostic or treatment.
Tissue Engineering, or Regenerative Medicine is based on cell therapy and on development of new techniques and new therapeutic modalities aiming to restore cells, tissues and the body integrity. The combination of Tissue Engineering with Biophotonics and Nanobiotechnology, as well its applications on different diseases, creates a number of possibilities of cure for various diseases, such as neurodegenerative diseases in central nervous system have been benefited by use of these tools for the development of novel target-specific drug delivery systems associated with well-defined activation protocols, which always seek a better biological response.
The theranostic materials have found promising applications in medicine. Investigations on novel nanomaterials for photo-hyperthermia applications are of great importance to understand the toxicity of nanomaterials at the molecular scale and the influence of lipids in the uptake process, bringing important benefits to the field of personalized nanomedicine. During the SBBN Congresses, several Radiobiologists from Europe and USA were invited to discuss all these topics with the Brazilian researchers, proposing new research projects.
Mechanical vibration and other physical agents
Human beings are continuously exposed to different modalities of factors, including the physical agents. The transmission and absorption of the energy associated with agents contribute to application to aid to treat or to detect early diseases. The comprehension of the mechanisms related to the biological effects due to the transference of the energy to the body in different levels are highly desired. Among the various physical agents, the interest in studies involving the application of the mechanical vibration has increased along of the years. Individuals are exposed to mechanical vibrations in daily activities, as walking and running, and the body responses properly to the absorption of the energy. It is suggested that the effects of the whole body vibration exercises are associated with neuroendocrinologic responses due to the plasma concentrations of some biomarkers have been altered. The investigations about whole body vibration exercises include the establishment of protocols considering biomechanical parameters, as frequency and peak to peak displacement have been performed, the time of the exposition and the periodicity of the protocols. The comprehension of the effects related to this physical agent is also important due to the human beings are exposed to mechanical vibrations generated in various sources.