Role of magnetic nanoparticles in targeted drug delivery for central nervous system

Introduction: The treatment of neurological disease, such as brain cancer or neurodegenerative diseases, is one of the most difficult challenges in medicine. The major limitation in this therapy is caused by asthenia of some drugs injected to the blood vessel to reach the main tissue of brain. There are three substrate obstacles that adjust molecular exchange in junction between blood and neurotic tissue or its steep spaces: the brain endothelium which makes blood-brain barrier (BBB), the arachnoids epithelium which makes intermediate substrate of meninges and the choroid plexus epithelium, which secretes cerebrospinal fluid (CSF). Methods: In recent years, some significant researches showed that magnetic nanoparticles (through conjugation of iron oxide NPs with hydrophilic polymer coatings of dextran) can be administered for impressive systemic and territorial transfer of therapeutics to the CNS. Nanoparticles also have the potential to revolutionize conventional imaging techniques. Conventional epitomize condition lack the association of high delicacy and high spatial precision required for molecular imaging. Results: Magnetic Resonance Imaging (MRI) has high resolution, but lacks sensitivity to molecular signals, while high sensitivity nuclear medicine modalities such as Individual photon ejaculation calculated tomography and position emission tomography (PET) provide superb sensitivity, at the cost of reduced spatial resolution. Using nanoparticles in some conditions such as MRI can amazingly enhance delicacy, presenting the potential for high resolution molecular imaging. MRI has high spatial resolution, is non-invasive in nature and offers multiplanar tomographic capabilities. Nanoparticles can be managed to have magnetized specifications that can be acquired by MRI at low condensations and at the same time include lingads which target specific molecules. Iron oxide nanoparticles have been widely researched for MRI, as there are several types, namely magnetite (Fe3O4) and hematite (α-Fe2O3), among which magnetite is very promising, because of its proven biocompatibility. For molecular imaging purposes, superparamagnetic iron oxide nanoparticles (SPIONs) need to bind to a range of drugs, proteins, enzymes, antibodies, or other molecular targets. In conclusion, using magnetized nanoparticles as a drug delivering system is still determined by its biocompatibility and optional aiming to the favorable cell or tissue under the guidance of external magnetic field (MRI scanner). Conclusion: Advances in current technologies and the expansion of magnetized nanoparticles as medicine transfer device to transfer medicine to tumor hypoxic zones have fast tracked in the past decade and led to the development of various magnetic nanoformulations such as liposomes, metallic, and polymeric nanoparticles. This technology will not only minimize invasive methods, nut also decrease side effects to intact fiber which are two primary concerns in conventional cancer therapies. The field of magnetic drug delivery is still at infancy, and combination of better magnetized medicine transfer device and association of multifunctional ligands are being continuously investigated so as to carry it from the bench-top to the clinic. Until Then the worries about the omission and long term toxicity remain barriers to clinical entry

Idiopathic generalized epilepsies and efficiency of advanced magnetic resonance imaging techniques in present era; perspectives in future

Epilepsy is a common disorder worldwide, with a prevalence of 4.5/1000 (0.45%) for youngsters and youths, and 1.54/1000 (0.15%) for the adult Chinese population in Hong Kong. up to 15% of epileptic patients can still leak the screening process of any structural lesion. In addition, the structural lesions detected on structural MR images may not reveal the correct degree and practical position of the abnormalities, especially with respect to malformations of cortical development. These include magnetic resonance spectroscopy (MRS) and perfusion weighted imaging (PWI). The widespread application of most of these techniques in clinical practice depends on the availability of high-performance MR imagers with the ability to accomplish fast echo-planar pulse sequences (echo-planar imaging), as well as substantial data processing capabilities. Using and PWI in study of microcirculation of tissues and vascular of lesional area on mechanisms by which selective drugs work and will provide new treatment targets for drug development. Finally, there is coupling of cerebral blood flow and metabolism, MR perfusion can act as a surrogate marker of metabolism as measured by MRS

Interaction of Dioxovanadium (V) ion with L-alanine at Different Ionic Strengths

The formation constants of species formed in the system H+ + alanine and VO2+ +alanine have been determined in aqueous solution for 1.0<pH<7.0 and at different ionic strengths ranging from 0.1 to 1.0 mol dm-3 NaClO4, using a combination of potentiometric and spectrophotometric techniques.The compositions of the formd complexes and their stability constants were determined by curve fitting method and it was shown that dioxivanadium(V) forms two mononuclear 1:1 and 1:2 species with alanineof type VO2L and VO2L2-.The porotonation constant of the amino group of alanine has been determined using potentiometric techniques and calculated using a computer program wich employ a least-squares method. The dependence of the porotonation of alanine and the stability constants of the species on ionic strength are described by a deby-huckel type equation

Role of diffusion tensor imaging as an imaging biomarker and theranostic tool in structural imaging of traumatic brain injury

Neuroimaging technology is at a "newborn" stage in the evaluation of TBI. While additional literature are obviously required to decide whether these modalities and progress in knowledge with noninvasive monitors will allow early and consistent recognition of revocable secondary brain damages, the final query is whether these new modalities will help in treatment plans that will absolutely mark result. DTI is an influential instrument for assessing white matter anatomy and related anomalies. DTI was formerly an investigation tool, but is using clinical practice. Accepting the terms and basic ideas of this method can aid in the clinical implementation and interpretation of this blend of structural and physiologic white matter evaluation. In conclusion, although DTI is as a diagnostic tool for severity of TBI and as an outcome predictor, but severe preclinical and clinical validation of each imaging method should be a top importance

Medical imaging modalities: Prevention of unnecessary orders and non-optimized radiation exposure

Magnetic resonance imaging (MRI) uses a constant magnetic field and radio waves, a non-invasive method for examining tissues, organs and the skeletal system. The advantages and disadvantages of MRI is not fully understood. In the computerized tumor (CT) scan, as an invasive method, the x-rays of the body is used for tomography; which different x-ray attenuation coefficient in tissues as well as the reconstruction of images could affect on the scanning of the patient and the received amount of radiation by the patient. However, compared to other radiographical diagnostic methods, CT scan could lead to the exposure of the patients against substantial radiation dosage, which may have several radiobiological effects such as delayed effects of radiation (possible effect) with the result of a variety of cancers, chromosomal failures and potential genetic abnormalities in the future generations. It is recommended that these tests would prescribe for the patients with greater accuracy and caution; with application of magnetic dosimeter for monitoring exposure of people who working with MRI (as its application for X-ray and CT scan)

Multiple Endocrine Neoplasia Type 2B: Eighteen-Year Follow-up of a Four-Generation Family

Seven members with multiple endocrine neoplasia type 2B from a 15-member family have been followed for 18 years. All affected had the neuroma phenotype in a distribution compatible with autosomal dominant inheritance. The phenotype features have allowed 100% initial and continuing prediction of affected versus nonaffected status in as early as 1.5 years. Among the affected: immunoreactive plasma calcitonin (iCT) concentration was high in 100%; thyroid palpation was false-negative in 71%; and thyroid scintiscan was false-negative in 83%. All had total thyroidectomy, plus lymphadenectomy in three, for bilateral medullary thyroid carcinoma (MTC) or C-cell hyperplasia (in the youngest). None has died directly from MTC. The index case died at age 68 and his son at age 32 years from complications of the syndrome. All but the youngest have continuing high iCT concentrations. No patient has had parathyroid disease. During preoperative calcium infusion, immunoreactive serum parathyroid hormone concentration declined by 35% to 84% of basal. At operation, macroscopically and microscopically normal parathyroid glands were found in all. No patient has had chemical suggestion of pheochromocytomas: at postmortem the index case had no adrenal medullary disease; his son had bilateral nodular adrenal hyperplasia; his daughter has had adrenal medullary hyperplasia and a renin-secreting juxtaglomerular tumor. Initially nonaffected members remain so

Walking Ability, Participation, and Quality of Life in Children with Spastic Diplegic Cerebral Palsy: A Path Analysis Study

  Objectives This study aims to design a conceptual model for the effect of various factors on walking ability, participation, and quality of life in children with spastic diplegic cerebral palsy (SDCP) and test it based on field data using path analysis. Materials & Methods This cross-sectional study was performed on 181 children with SDCP. The following were used to measure each of the variables: the Modified Ashworth Scale, the Micro Manual Muscle Tester, the Timed Up and Go Test (TUG), the Boyd and Graham test, the goniometer, weight and height, the Gross Motor Function Classification System, the Life Habits Questionnaire, and cerebral palsy Quality of Life Questionnaire for Children. The structural model was tested in Amos 17. Results All paths of the proposed model were significant (P <0.05). Among evaluated variables, muscle strength (B = -0.466), balance (B = 0.326), and spasticity (B = 0.143) affected walking ability. Moreover, as an intermediate factor, walking ability affected the subjects’ participation (B = -0.819) and quality of life (B = -0.183). Conclusion Muscle strength, balance, and spasticity are the most influential factors in the walking ability of children with SDCP. Furthermore, walking ability and participation are two critical factors in promoting the quality of life of these children