Glutamic acid-coated Fe3O4 nanoparticles for tumor-targeted imaging and therapeutics.

We have developed surface functionalised Fe3O4 magnetic nanoparticles (MNPs) based system that can be used for tumor-targeted multimodal therapies and MR imaging. Biocompatible, non-essential amino acid (glutamic acid) was introduced onto the surface of Fe3O4 MNPs to provide functional sites for binding of chemotherapeutic drugs. These glutamic acid-coated Fe3O4 MNPs (GAMNPs) exhibit good water-dispersibility, magnetic responsivity and pH dependent charge conversal feature. The magnetic core as well as organic shell of GAMNPs was characterized by XRD, TEM, DLS, FTIR, PPMS and UV-visible spectroscopy and zeta-potential analyzer etc. The broad spectrum anticancer drugs, doxorubicin hydrochloride (DOX) and methotrexate (MTX) were electrostatically and covalently conjugated to the surface of GAMNPs, respectively for combination chemotherapy. These dual drugs loaded system (DOX-MTX-GAMNPs) shows pH dependent release behaviour of both the drugs and enhanced toxicity towards breast cancer cell line (MCF-7) as compared to their individual treatment. Fluorescence microscopy and flow cytometric analyses confirmed the successful uptake of drug loaded system into MCF-7 cell lines. Further MTX being analogue of folic acid, its co-delivery with DOX would help in internalization of both the drugs into MCF-7 cells. These GAMNPs also show good heating efficiency under AC magnetic field (Intrinsic loss power, ILP = 0.95 and 0.73 and 0.48 nHm2/Kg at Fe concentration of 0.5, 1 and 2 mg/ml, respectively) and transverse relaxivity (r2 = 152 mM-1 s-1) indicating their potential capability for hyperthermia therapy and MRI tracking. Furthermore, it has been observed that the combination of chemotherapeutic drugs and hyperthermia leads to an enhancement of cytotoxicity in MCF-7 cells.

Carboxyl decorated Fe3O4 nanoparticles for MRI diagnosis and localized hyperthermia.

We report the development of carboxyl decorated iron oxide nanoparticles (CIONs) by a facile soft-chemical approach for magnetic resonance imaging (MRI) and hyperthermia applications. These superparamagnetic CIONs (~10 nm) are resistant to protein adsorption under physiological medium and exhibit good colloidal stability, magnetization and cytocompatibility with cell lines. Analysis of the T2-weighted MRI scans of CIONs in water yields a transverse relaxivity (r2) value of 215 mM(-1) s(-1). The good colloidal stability and high r2 value make these CIONs as promising candidates for high-efficiency T2 contrast agent in MRI. Further, these biocompatible nanoparticles show excellent self-heating efficacy under external AC magnetic field (AMF). The infrared thermal imaging confirmed the localized heating of CIONs under AMF. Thus, these carboxyl decorated Fe3O4 nanoparticles can be used as a contrast agent in MRI as well as localized heat activated killing of cancer cells. Furthermore, the active functional groups (COOH) present on the surface of Fe3O4 nanoparticles can be accessible for routine conjugation of biomolecules/drugs through well-developed bioconjugation chemistry.

Acute encephalopathy with biphasic seizures and late reduced diffusion.

Acute encephalopathy with biphasic seizures and reduced diffusion (AESD) is a syndrome of encephalopathy characterized by biphasic seizures and altered consciousness in the acute stage followed in the subacute stage by restricted diffusion in the subcortical white matter on magnetic resonance imaging. The etiology of AESD has been attributed to viral infection like influenza A and human herpes virus 6. The exact pathogenesis of AESD is uncertain. Here we report a case of AESD, diagnosed based on clinicoradiological correlation.

Antenatal diagnosis of iniencephaly: sonographic and MR correlation: a case report.

Iniencephaly is an uncommon and fatal neural tube defect involving the occiput and inion, this occurs together with rachischisis of the cervical and thoracic spine, and retroflexion of the head. We report the ultrasound (US) and magnetic resonance (MR) imaging findings of a case of iniencephaly with clubfeet and arthrogryposis. The diagnosis of iniencephaly is easy to make on ultrasound due to the typical star-gazing fetus. However, the details of the fetal brain and spinal cord may not be adequately delineated on US. We found MR imaging to be superior for depicting central nervous system abnormalities. MR imaging has evolved as an imaging modality and it is complementary to fetal US, yet US remains the screening modality of choice.

MRI diagnosis of hypertrophic osteoarthropathy from a remote childhood malignancy.

Hypertrophic osteoarthropathy (HOA) is a clinico-radiological syndrome characterized by digital clubbing, periosteal proliferation, bone pain, synovitis and arthralgia, all of these being commonly symmetrical. It is occasionally associated with nasopharyngeal lymphoepitheliomas and may develop before or after development of lung metastases in these patients. We report a case of a healthy 22-year-old female who presented to our institution with pain and swelling in the thighs and legs. She had a history of childhood nasopharyngeal lymphoepithelioma. Radiographs of the knees were negative. Magnetic resonance imaging (MRI) showed features suggestive of bilateral periostitis. Because of the propensity of the rare childhood nasopharyngeal lymphoepithelioma to present with HOA, this entity was included in the differential diagnosis. A subsequent chest radiograph and CT demonstrated a lung and mediastinal mass that were histologically confirmed to be metastatic. To the best of our knowledge, HOA and metastases from nasopharyngeal lymphoepithelioma occurring after such a long time interval have not been previously reported. Early demonstration and consideration of HOA on the basis of MRI, lead to expeditious and appropriate subsequent investigation.

Pre- and post-therapy MR imaging in fibrodysplasia ossificans progressiva.

Fibrodysplasia ossificans progressiva, also known as myositis ossificans progressiva, is characterized by congenital skeletal malformations and progressive ectopic bone formation in connective tissues. The disorder presents as rapidly growing masses usually in the neck or paraspinal region with stiffness in the adjoining joints. The preosseous lesions involve the fascia, ligaments, tendons, and skeletal muscle. These lesions occasionally resolve but more often progress to form ectopic ossification. We present a boy who had a characteristic clinical presentation. Magnetic resonance (MR) imaging conducted in the preosseous stage of the lesion revealed the pathology, resulting in early therapy and resolution of the preosseous lesion without progression to ossification. To the best of our knowledge, post-therapy follow-up MR imaging in such a case has not been reported.