Oncolog-Hematolog Nr. 34 (1/) by Versa Media - Issuu

Aggressive cancer and chemotherapy

Introduction Cancer is a group of diseases which cause an abnormal and uncontrolled cell division coupled with malignant behavior such as invasion and metastasis [ 1 ].

For the treatment of cancer various methods have already been discovered and many others are in the process of discovery aggressive cancer and chemotherapy. But the anticancer drugs can fail to kill cancer cells for various reasons, the transport of the anticancer drug being governed by physiological and physicochemical properties of the target cell and of the drug itself [ 4 ].

These properties include pressure, charge, size, configuration, electrochemical properties, hydrophilicity, etc. For the therapeutic agents delivery to the tumor cells, the following problems can be addressed, as follows: Drug resistance at the tumor levels non cellular based mechanisms ; Drug resistance at cellular level cellular based mechanisms ; Pharmacokinetic properties of the anticancer agent in the body [ 5 ].

The concept of the nanoparticles which permits higher absorption of the drugs in a specific tissue, and this concept has been applied for hyperthermia, radiation therapy, photodynamic therapy, etc. Meanwhile, the aggressive cancer and chemotherapy opened new horizons for drug delivery and bringing the term nanomedicines.

Fundraiser has ended About My wife and I collect this donation for our friend Florin aggressive cancer and chemotherapy has great health problems and needs our help. Any donation is appreciated, and Florin will be closer to finishing the treatment that will give him a new chance to live: "My name is Opris Florin Alexandru, I am 33 years old and married to Arabela for eight years. God has blessed us so far with two beautiful girls, Alessia 7 years and Maria 5 years. I normally work as a dental technician, but I do not currently practice due to the terrible diagnosis received in Julynotably stage IV IV-glioblastoma, the most aggressive form of brain cancer. So far we have undergone 4 surgeries, followed by chemotherapy and radiotherapy, but the tumor recurred.

Nanomedicine is the medical application for diagnosis and treatment of different human diseases by means of small particles, known as nanoparticles with sizes of nm. The nanoparticles are known by their large aggressive cancer and chemotherapy area, high reactivity, high solubility, reduced side effects and low toxicity [ 7 - 9 ].

The main nanoparticles applied in nanomedicine are: polymeric nanoparticles, liposomes and lipid nanoparticles, micelles, microcapsules, magnetic particles, and carbon nanoparticles fullerenes, carbon nanotubes, carbon nanofibers, etc and the nanoassemblies [ 10 - 12 ].

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Photodynamic therapy PDT as a part of photochemotherapy, is a concerted method where, in addition to light and an administered drug, oxygen is required. PDT represents a concerted action of light, with a sensitizers and an oxygen active specie singlet oxygen which preferentially actions on tumor cells and not on healthy cells. The administered drug is generally a substance which can efficiently photosensitize the formation of singlet oxygen or other reactive species derived from oxygenand such species react with different biological targets, and cause cellular damage and finally, the cellular death.

Activation of the aggressive cancer and chemotherapy by light is an essential condition for a successful PDT. Under such circumstances, this chapter offers the most up—to—date coverage of photodynamic therapy including information on how nanosensitizers, have evolved within the field of cancer therapy and more recently for drugs controlled release in this field, by using personal data correlated with literature reports. Short history Photodynamic therapy is dating from ancient time, the Indian civilizations reported from aggressive cancer and chemotherapy first time the combined action of psoralens with sunlight to treat vitiligo [ 14 ].

Niels Fiensen used UV light to treat small pox, pustular infections eruptions, cutaneous tuberculosis, and for its results he obtained the Nobel Prize in Medicine in Similar results obtained Aggressive cancer and chemotherapy Raab inby using eosin as sensitizer and combining his results with Jesionek and J.

Prime results for skin tumors and epilepsy generated by light induced dermatitis [ 17 ]. Meyer-Betz was the only experimentalist who tested this method on himself, by injecting haematoporphyrin, reporting the observed effects: oedema, erythema and light sensitivity [ 18 ].

Later, Campbell and Hill studied the PDT effects aggressive cancer and chemotherapy href="http://evenimente-corporate.ro/764-que-es-la-papiloma-humano.php">que es la papiloma humano microcirculation, reporting the thrombosis and vascular shutdown [ 19 ].

Lipson in went on to treat a patient with a large cancer of the breast following an injection of a aggressive cancer and chemotherapy of haematoporphyrin HpD. The modern era of photodynamic therapy was established by Dr.

1. Introduction

Dougherty, at the Division of Radiation Biology at Roswell Park Memorial Institute, Buffalo, USA, who reported that a systematically injected porphyrin on activation with red light caused complete eradication of transplanted experimental tumors [ 20 ]. In the photodynamic therapy occur three types of mechanisms: type I mechanism — electron transfer eT where the photosensitizer excited state generates a radical species, for example by electron transfer from or to a substrate, or by hydrogen atom abstraction from a substrate.

Aggressive cancer and chemotherapy type I mechanism of PDT In type II mechanism - aggressive cancer and chemotherapy transfer ET an energy transfer occurs from the excited photosensitizer to molecular oxygen, to give the sensitizer in its ground state and singlet oxygen.

In this mechanism electronic excitation energy is transferred from the excited triplet T1 of the sensitizer generated by intersystem crossing isc from the ecited singlet S1 to triplet molecular oxygen, to give the sensitizer in its ground state S0 and singlet oxygen 1O2.

Sheme 2. The type II mechanism of PDT Major biological targets are membranes that undergo rupture and the cells are destroyed through the membranes around the mitochondria and the lysosomes.

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These organelles induce subsequent cellular destruction by necrosis or apoptosis [ 21 - 24 ]. Except these two types of mechanisms, there is another one: type III mechanism, which take place when the oxygen is absent in the system. Sheme 3. Photosensitizers 4. Conventional photosensitizers All the sensitizers could be natural or synthetic compounds, with proper absorption properties from aggressive aggressive cancer and chemotherapy and chemotherapy light source. They should be pure compounds, soluble in body fluids, with high capacity to be incorporated in malignant cells.

For instance, hair loss, which is one of the major concerns for some patients, such as a young lady with BM of breast cancer, is a less frequently encountered problem with SRS than WBRT as a result of the smaller irradiated field size and focalized dose distribution Figure 2. All the aforementioned advantages of SRS are provided by utilization of multiple convergent narrow beams to deliver high dose focal irradiation in a single fraction by using multiple cobalt sources, linear accelerators or cyclotrons 37, Similar with neurosurgery, SRS alone or in combination with WBRT has been exhibited to associate with prolonged overall survival, local control and also better neurologic status in these patients compared to WBRT alone 33,

Also, they should be fluorescent and able to generate singlet oxygen, which is the excited state of oxygen efficient on malignant cells [ 25 ]. Taking into account all these criteria and knowing the compatibility with human body, the porphyrins are known as ideal sensitizers for photodynamic therapy.

Oncolog-Hematolog Nr. 34 (1/) by Versa Media - Issuu

The general chemical structure for some porphyrins and phthalocyanines as PDT agents are represented in Figure 1. Figure 1. The chemical structure of some porphyrins and phthalocyanines First Generation Photosensitizers, includes Photofrin® and HpD and exist as complex mixtures of monomeric, dimeric, and oligomeric structures.