Combining magnetic hyperthermia and dual T1/T2 MR imaging using highly versatile iron oxide nanoparticles.

Magnetic hyperthermia and magnetic resonance imaging (MRI) are two of the most important biomedical applications of magnetic nanoparticles (MNPs). However, the design of MNPs with good heating performance for hyperthermia and dual T1/T2 contrast for MRI remains a considerable challenge. In this work, ultrasmall superparamagnetic iron oxide nanoparticles (USPIONs) are synthesized through a simple one-step methodology. A post-synthetic purification strategy has been implemented in order to separate discrete nanoparticles from aggregates and unstable nanoparticles, leading to USPIONs that preserve chemical and colloidal stability for extended periods of time. The optimized nanoparticles exhibit high saturation magnetization and show good heating efficiency in magnetic hyperthermia experiments. Remarkably, the evaluation of the USPIONs as MRI contrast agents revealed that the nanoparticles are also able to provide significant dual T1/T2 signal enhancement. These promising results demonstrate that USPIONs are excellent candidates for the development of theranostic nanodevices with potential application in both hyperthermia and dual T1/T2 MR imaging.

Trabectedin for reversing platinum resistance and resensitization to platinum in patients with recurrent ovarian cancer.

AIMS: We evaluated trabectedin in patients with platinum-resistant/refractory and partially platinum-sensitive recurrent ovarian cancer and the outcomes after reintroduction of platinum. METHODS: Twenty-seven patients (platinum-resistant/refractory n = 24/PPS; n = 3) treated with trabectedin were retrospectively analyzed. RESULTS: Trabectedin resulted in an objective response rate (ORR) of 18.2% with a 59.1% of disease control rate (ORR plus stable disease). The median progression-free and overall survival were 3.0 and 21.3 months, respectively. Subsequently, 17 patients were retreated with platinum and yield an ORR of 41.2% and DCR of 47.0%. The median progression-free and overall survival after platinum rechallenge were 5.0 and 14.7 months, respectively. CONCLUSION: Our results suggest that trabectedin may contribute to resensitize tumor cells to platinum rechallenge.

Indirect calculation of monoclonal antibodies in nanoparticles using the radiolabeling process with technetium 99 metastable as primary factor: Alternative methodology for the entrapment efficiency.

The use of monoclonal antibodies (Mab) in the current medicine is increasing. Antibody-drug conjugates (ADCs) represents an increasingly and important modality for treating several types of cancer. In this area, the use of Mab associated with nanoparticles is a valuable strategy. However, the methodology used to calculate the Mab entrapment, efficiency and content is extremely expensive. In this study we developed and tested a novel very simple one-step methodology to calculate monoclonal antibody entrapment in mesoporous silica (with magnetic core) nanoparticles using the radiolabeling process as primary methodology. The magnetic core mesoporous silica were successfully developed and characterised. The PXRD analysis at high angles confirmed the presence of magnetic cores in the structures and transmission electron microscopy allowed to determine structures size (58.9 ±â€¯8.1 nm). From the isotherm curve, a specific surface area of 872 m2/g was estimated along with a pore volume of 0.85 cm3/g and an average pore diameter of 3.15 nm. The radiolabeling process to proceed the indirect determination were well-done. Trastuzumab were successfully labeled (>97%) with Tc-99m generating a clear suspension. Besides, almost all the Tc-99m used (labeling the trastuzumab) remained trapped in the surface of the mesoporous silica for a period as long as 8 h. The indirect methodology demonstrated a high entrapment in magnetic core mesoporous silica surface of Tc-99m-traztuzumab. The results confirmed the potential use from the indirect entrapment efficiency methodology using the radiolabeling process, as a one-step, easy and cheap methodology.

Magnetic core mesoporous silica nanoparticles doped with dacarbazine and labelled with 99mTc for early and differential detection of metastatic melanoma by single photon emission computed tomography.

Cancer is responsible for more than 12% of all causes of death in the world, with an annual death rate of more than 7 million people. In this scenario melanoma is one of the most aggressive ones with serious limitation in early detection and therapy. In this direction we developed, characterized and tested in vivo a new drug delivery system based on magnetic core-mesoporous silica nanoparticle that has been doped with dacarbazine and labelled with technetium 99 m to be used as nano-imaging agent (nanoradiopharmaceutical) for early and differential diagnosis and melanoma by single photon emission computed tomography. The results demonstrated the ability of the magnetic core-mesoporous silica to be efficiently (>98%) doped with dacarbazine and also efficiently labelled with 99mTc (technetium 99 m) (>99%). The in vivo test, using inducted mice with melanoma, demonstrated the EPR effect of the magnetic core-mesoporous silica nanoparticles doped with dacarbazine and labelled with technetium 99 metastable when injected intratumorally and the possibility to be used as systemic injection too. In both cases, magnetic core-mesoporous silica nanoparticles doped with dacarbazine and labelled with technetium 99 metastable showed to be a reliable and efficient nano-imaging agent for melanoma.

Carbon-11 radiolabelling of organosulfur compounds: (11) C synthesis of the progesterone receptor agonist tanaproget.

Herein a new (11) C radiolabelling strategy for the fast and efficient synthesis of thioureas and related derivatives using the novel synthon, (11) CS2 , is reported. This approach has enabled the facile labelling of a potent progesterone receptor (PR) agonist, [(11) C]Tanaproget, by the intramolecular reaction of the acyclic aminohydroxyl precursor with (11) CS2 , which has potential applications as a positron emission tomography radioligand for cancer imaging.

Lapatinib plus trastuzumab in pretreated human epidermal growth factor receptor 2-positive metastatic breast cancer.

BACKGROUND: Dual human epidermal growth factor receptor 2 (HER2) blockade has been preclinically and clinically assessed in HER2-overexpressing metastatic breast cancer (mBC) with encouraging results. PATIENTS AND METHODS: This is a descriptive retrospective study of trastuzumab plus lapatinib activity in patients with HER2-overexpressing mBC from two centers. The primary endpoints were to assess objective response rate (ORR) and toxicity. The secondary endpoints were to assess progression-free survival (PFS) and overall survival. RESULTS: A total of 23 HER2-positive mBC patients previously treated with trastuzumab received a trastuzumab plus lapatinib based therapy. Chemotherapy (CT) was added to the dual HER2 blockade treatment in 13 patients (56%), whereas hormonotherapy (HT) was added in 8 patients (35%) and 2 patients (9%) received lapatinib plus trastuzumab without any other agent. ORR was 22% (5/23) and 39% (9/23) of patients had stable disease. PFS in the overall population was 4 months. PFS in patients with CT was 5 months, whereas PFS in patients with HT was 2 months. Grade≥3 adverse events were diarrhea (26%) and hand-and-foot syndrome (9%). CONCLUSIONS: These findings suggest that dual HER2 blockade in combination with CT is feasible in pretreated HER2-positive mBC patients.