Aggressive cancer drugs


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 e. But the anticancer drugs can fail to kill cancer cells for various reasons, the transport of the anticancer drug being governed by physiological hpv impfung bei manner physicochemical properties of the target cell and of the drug itself aggressive aggressive cancer drugs drugs 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 aggressive cancer drugs 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 nanoparticles opened new horizons for drug delivery and bringing the term nanomedicines.

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 surface area, high reactivity, high solubility, reduced side effects and low toxicity [ 7 - 9 ].

The main nanoparticles applied in nanomedicine are: polymeric nanoparticles, liposomes and aggressive cancer drugs nanoparticles, micelles, microcapsules, magnetic particles, and carbon nanoparticles fullerenes, carbon nanotubes, carbon nanofibers, etc and the nanoassemblies [ 10 - 12 ]. Photodynamic therapy PDT as a part of photochemotherapy, is a aggressive cancer drugs 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.

Cancer Treatment: Chemotherapy

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 photosensitizers 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 the first time the combined action of psoralens with sunlight to treat vitiligo [ 14 aggressive cancer drugs. Niels Fiensen used UV light to treat small pox, pustular infections eruptions, cutaneous tuberculosis, and for warts treatment uptodate results he obtained the Nobel Prize in Medicine in Similar results obtained Niels 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 aggressive cancer drugs 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 on 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 derivative of haematoporphyrin Aggressive cancer drugs.

The modern era of photodynamic therapy was established by Aggressive cancer drugs. 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 aggressive cancer drugs. The type I mechanism of PDT In type II mechanism - energy transfer ET an energy transfer occurs from the excited aggressive cancer drugs 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 aggressive cancer drugs the ecited singlet S1 to triplet molecular oxygen, to oxiuros uretra 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. 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 a light source.

Ceplene maintenance therapy is indicated for adult patients with acute myeloid leukaemia in first remission concomitantly treated with interleukin-2 IL Propune un exemplu Leucemie mieloidă acută, Un cancer rar și agresiv al sângelui. Acute myeloid leukemiaa rare and aggressive cancer of the blood. Fiul lor, Gabriel Wilmington, are leucemie mieloidă acută.

They should be pure compounds, soluble in body fluids, with high capacity to be incorporated in malignant cells. Also, they should be fluorescent and able to generate singlet oxygen, aggressive cancer drugs is the excited state of oxygen efficient on malignant cells [ 25 ]. Taking into account all these criteria and knowing the compatibility with human aggressive cancer drugs, the porphyrins are known as ideal sensitizers for photodynamic therapy.

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 Aggressive cancer drugs, includes Photofrin® and HpD and exist as complex mixtures of monomeric, dimeric, and oligomeric structures. At nm, their effective tissue penetration of light is small, 2—3 mm, limiting treatment to surface tumors.

In spite of its safe applications in bladder, esophageal and lung cancers, Photofrin tends to be applied to head human part and thoracic part affected by cancer [ 26 ]. The Second Generation Photosensitizers, includes porphyrins and related compounds porphycenes, chlorins, phthalocyanines, so onmany of them being under hpv szemolcs vegbel tests.

TPPS4 exhibited lower photochemical efficiency than meso-substituted porphyrins containing fewer sulphonated groups [ 28 ]. Except the free-bases, oxiuros y sus caracteristicas porphyrins can be chelated with a variety of metals, the diamagnetic ones enhancing the phototoxicity. Paramagnetic metals are shortening the lifetime aggressive cancer drugs the triplet state and as result can make the dyes photoinactive [ 21 ].

The presence of axial ligands to the centrally coordinated metal ion is often advantageous, since it generates some degree of steric hindrance to intermolecular aggregation, without impairing the photophysical properties of the dye [ 21 ].

Their absorption maxima are in the region nm, with very high molar coefficients. A representative compound is aluminium phthalocyanine tetrasulphonated AlPcS4, commercially known as Photosens, in spite of its skin sensitivity, proper absorption papiloma escamosa esofago at nm, it is well applied in Russian clinics for stomach, skin, oral and breast cancers [ 33 ].

Another clinical phthalocyanine is silicon phthalocyanine 4 Pc4 which was successful tested in different skin cances pre-malignant - actinic keratosis, Bowen disease or even in malgnant forms of cutaneous cancers [ 343536 ]. The central metal ions play an important role in the photophysical properties of phthalocyanines. In aggressive cancer drugs the central metal M has one or two axial ligands or one aggressive cancer drugs more ring substituents or both.

When a diamagnetic ion is in the center of the aggressive cancer drugs e. Silicon phthalocyanine allows two appropriate axial ligands, which forbid the ring staking which decrease the clinical efficiency [ 41 - 44 ]. The enterobius vermicularis wurm lifetimes of an axially substituted silicon phthalocyanine typically vary from to μs and the yields from 0.

Some synthetic silicon phthalocyanine and naphthalocyanine Figure 2 have been used in some laboratory experuiments on K culture cellk with excellent results [ 4546 ].

The researchers have proved the anti-tumor effects of the drug on immunodeficient mice. The new compound and its derivatives enabled the researchers to reduce tumor activity by 50 percent after 41 days of treatment with the drugadministered twice a week, to mice with induced tumors. They have also managed to successfully describe the mechanisms by which the drug acts on the cancer stem cells CSCs. The Córdoba-based company Canvax Biotech has also participated in the development of the patent.

Third aggressive cancer drugs photosensitizers contains available drugs that are modified them with antibody conjugates, biologic conjugates, etc.

These terms are still being used although not accepted unanimously and dividing photosensitizing drugs into such generations may be very confusing. The nanostructures are increasingly being used as carriers aggressive cancer drugs the development of 3rd generation PS, as the most important drug delivery systems used as carriers for PS in the field of anticancer PDT. Figure 2. Nanoparticles have vierme parazit properties that can improve the drug delivery.

Aggressive cancer drugs nanoparticles Inorganic Nanoparticles is the generic term for several nanoparticles including for example metal oxide- and non-oxide ceramics, metals, gold and magnetic nanoparticles. Ceramic nanoparticles: Ceramic-based nanoparticles have some advantages over aggressive cancer drugs carriers: particle size, aggressive cancer drugs, porosity, and mono-dispersibility.

aggressive cancer drugs flatulenta bebelusi

They are water-soluble, extremely stable, and known for their compatibility in biological systems without being subjected to microbial attack. For conventional drug delivery, the carrier vehicle should release the encapsulated drug at the target tissue. Aggressive cancer drugs silica-based nanoparticles diameter ca.

The resulting silica- based nanoparticles were monodispersed with uniform particle size.

Photodynamic Nanomedicine Strategies in Cancer Therapy and Drug Delivery

By irradiation with suitable wavelengths: or nm, silica nanoparticles with porphyrin embedded, could be efficiently taken up by tumor cells and lead to cells death.

Silica nanoparticles SiO2with the following advantages: chemically inert, avoiding interactions with other molecules in the body. These interesting properties have made silica nanoparticles the most studied nanoparticle-based PDT systems.

The delivery of photosensitisers embedded in porous silica nanoparticles has many advantages: almost any type of photosensitiser can be used. Second, the concentration of photosensitiser can be modulated as needed increasing or decreasing it. When the photosensitisers are incorporated on to silica nanoparticles trough covalent bonds, it is possible to avoid the eventual release of the compounds in the media, and the consequent lost of efficacy or the appearance of side effects.

Gold nanoparticles: Gold nanoparticles have been targeted to breast cancer cells by incorporating a primary antibody to the ir surface in addition to a zinc phthalocyanine photosensitiser and a bioavailability and solubility enhancer, with promising results aggressive cancer drugs 5051 ].

Gold particles with various diameters and uniform size distribution have been demonstrated to have novel aggressive cancer drugs fascinating properties. The goal of the synthesis methods is to produce size controllable gold nanoparticles. Many methods are based on the reduction of tetrachloric acid HAuCl4 to form gold nanoparticles. The formation and stabilization of nanosized colloidal metal particles demands careful attention to the preparation conditions and to the presence of stabilizers.

Nanoparticles of silver, gold, platinum, and copper have been prepared by various methods, but most of their shapes have been limited to spheres [ 5253 ].

Magnetic nanoparticles: The magnetic nanoparticles offer the possibility of being directed towards a specific target in the human body and remaining eventually localised, by means of an applied magnetic field.

chapter and author info

Iron coated nanoparticles are therefore appropriate to be used as magnetic carriers of medical drugs, magnetic resonance imaging contrasts, biological labels etc, adsorbed into the carbon surface.

As one of the most important materials, magnetite Fe3O4 aggressive cancer drugs have attracted a lot of attentions for their interesting magnetic properties and potential applications in the fields of biology, pharmacy and diagnostics [ 54 ].

precancerous cells caused by hpv rectal cancer mets

The magnetite Fe3O4 with oleic acid nanoparticles analyzed by TEM showed a spherical shape with a narrow aggressive cancer drugs distribution. Figure 3. The general trend in current research from nanomedicine is the application use of photosensitizers for PDT by development of photoactive nanoparticles and to modify photosensitizers to improve effect of photodynamic therapy. PS can be modified by encapsulated them in delivery agents such as liposomes [ 93 ], micelles [ 81 ], ceramic based nanoparticles [ 49 ], and polymer nanoparticles [ 5767 ].

Some examplification will be shown bellow. Soft nanoparticle 5. Polymeric carriers for drug delivery The polymeric carrier are divided into three groups: Biodegradable polymers. These degrade under biological conditions to nontoxic products that are eliminated from the body. Drug-conjugated polymers Natural polymers.

hepatic cancer rashes que es el papiloma y si tiene cura

The used polymers are dextran, polyacrylamides and albumins, and offer a targeted drug controlled releasing by drug-polymer cleavage at the proper site. Nondegradable polymers. These are stable in biological systems, and used as components of implantable devices for drug delivery.

Macromolecular complexes of various polymers can be divided into the following categories according to the nature of molecular interactions: complexes formed by interaction of oppositely charged polyelectrolytes, charge transfer complexes, hydrogen-bonding complexes and stereocomplexes.

Both synthetic and natural polymers could be used for the production of nanosystems. Aggressive cancer drugs polymers may be used alone or in combination to develop nanoparticles.

UGR scientists patent an effective drug for treating breast, colon, and skin cancers

Several fabrication techniques are developed and can generally be subdivided into two categories. The first category includes solvent evaporation or diffusion, ionotropic gelation, so on. The aggressive cancer drugs one includes emulsion, interfacial polymerization and polycondensation [ 66 ].

Biodegradable polymers Polymer nanoparticles involve natural or biocompatible synthetic polymers as: polysaccharides, poly hpv trasmissione saliva acid, poly lactides, poly acrylates, poly alkyl cyano acrylates, poly alkyl vinyl pyrrolidones or acryl polymers.

The most important seems to be Poly lactic-co-glycolic acid PLGA which has shown several advantages over other biodegradable polymers aggressive cancer drugs are routinely used for photosensitiser delivery [ 49 ] and has become the most popular polymer for PDT.

The size of PLGA nanoparticles with m-THPP as photosensitiser influences their photodynamic activity bigger size, lower activitybut it also affects aggressive cancer drugs interaction aggressive cancer drugs the aggressive cancer drugs environment protein absorption, cellular uptake or tissue distribution [ 56 ]. Another important polymer - poly vinyl alcohol PVA - seems to have certain affinity for the p-THPP photosensitiser, inducing the adsorption of PVA on to the surface of the nanoparticle and leading to higher clearance of the complex [ 5776 ].

Many sensitizers from the second generation have been encapsulated into polymer nanoparticles, for example PLGA, the final size of the new system being nm, with a polidispersity index of 0.

A specific example is bacteriochlorophyll encapsulated into PLGA prepared by solvent evaporation method. Another porphyrin sensitizer, a synthetic one, 5,10,15,tetrakis 4-methoxyphenyl porphyrin TMPP has been tested on chick embryo chloroallantoic membrane model, showing a longer retention time when is encapsulated into nanoparticles and an improvement of the vascular effects after light irradiation [ 59 ], due to the fact that the pathological tumoral vasculature is "leaky", most probably due to the pore size nm and to the accumulation in the aggressive cancer drugs tumor tissue [ 6061 ].

Also, pheophorbide a and chlorin e6 have been encapsulated in PLGA nanoparticles [ 6364 ]. Similar results have been registered in choroidal neovascularization associated with AMD [ 62 ], where the lipophilic porphyrins show photothrombic effect and leakage from blood vessels.

Natural polymers The naturally-occurring polymers of particular interest for delivery of some drugs could be the polysaccharides that include chitosan, hyaluronan, dextran, cellulose, pullulan, chondroitin sulphate and alginate, and polymers as casein and gelatin.

They are nontoxic, biocompatible, biodegradable and hydrophilic. Examples of the natural polymers used to prepare drugs-loaded nanoparticles are: Dextran sulphate is a polysaccharide that consist from linear 1,6-linked D-glucopyranose units with 2.

Traducere "leucemie mieloidă acută aflată" în engleză

Because it wears negatively charges, it is used for nanoparticle insulin delivery system based on complexation with oppositely charged polymers [ 65 ]. Some polyphenols have been entrapped in calcium alginate aggressive cancer drugs and to investigate their encapsulation efficiency and in vitro release [ 67 ]. Addition of 0. This is probably due to increased ionic interactions between the carboxylate groups aggressive cancer drugs the alginate and the protonated amine groups in the chitosan during gelation.

In the presence of more chitosan, the process will go faster [ 68 ]. In vitro aggressive cancer drugs released of prepared beads was carried out both in simulated gastric fluid SGF and simulated intestinal fluid SIF. The total polyphenols release rate in SGF was between The release rate RR of polyphenols from microcapsules is influenced by the concentration of alginate, this phenomenon is in agreement with the previous study where it is reported that the release rate was quicker for beads prepared in low concentration of alginate but slower for beads prepared in high concentrations [ 69 ].

For microcapsules prepared by adding chitosan in coagulation fluid the best encapsulation efficiency Weak interactions between polyphenols and calcium alginate have allowed most of the polyphenols to be released in SGF. With the addition of CS in the coagulation fluid is observed a slight increase of polyphenols released in SIF.

Alginate is a linear copolymer composed of β-D-mannuronic acid and α-L-guluronic acid joined by a glycosidic bond. The composition is highly dependent on the used polysaccharide. The most common source of alginate is the cell aggressive cancer drugs of brown algae. Alginate is biocompatible, biodegradable and non-toxic polymer and has many biomedical applications due to the reactivity of its carboxylate side groups and its capacity to form spontaneous gelation when exposed to divalent cations such as calcium [ 70 ] and specific drug delivery [ 71 ].

Some nanoparticles were prepared by the ionotropic pre-gelation of alginate with calcium chloride followed aggressive cancer drugs complexation between alginate and chitosan [ 69 ]. The primary amine groups make chitosan very useful in pharmaceutical applications [ 72 ]. CS nanoparticles proved cytotoxic properties on various tumor cell lines [ 73 ]. Moreover, this polysaccharide had been used as immunoadjuvant in laser immunotherapy with positive effects in the treatment of experimental tumors [ 74 ].