99mTc-Methionine Gold Nanoparticles as a Promising Biomaterial for Enhanced Tumor Imaging.

Methionine-gold nanoparticles (MGNs) was synthesized by conjugating methionine via dithiocarbamate linkage to gold nanoparticles (GNPs), prepared simultaneously by one pot modified Burst method. Formation of MGNs was confirmed by UV-visible spectroscopy and appearance of new IR bands in the range of 934 cm-1 to 1086 cm-1 and shifting of N-C,S-S and S-C-S stretching, confirms the involvement of '-S-C-S-' group of methionine dithiocarbamate with GNPs. The presence of Au in MGNs was confirmed by EDXA spectrum, whereas TEM, SAED and XRD revealed that MGNs are nanocrystalline (~13 nm) and have face-centered cubic structure. MGNs was labeled with 99mTc (TMGNs) with radiolabeling efficiency greater than 99% using 300 µg of stannous chloride, pH 7 and 90.6 MBq of 99mTcO4. The stability data showed that the conjugate will remain infrangible in systemic circulation and in acidic microenvironment of tumor. The blood kinetic profile of TMGN in rabbits and biodistribution studies in EAT tumor bearing balb/c mice showed longer in vivo circulation and slow clearance compared to radiolabeled methionine (TM). TMGN demonstrated nearly three-fold higher tumor accumulation (3.9 ± 0.35% ID/g), 2-fold lower tumor saturation dose (1.0 µg/kg) and higher tumor retention compared with TM. Data showed that the TMGN tumor: blood ratio (1.05) is nearly 2.5-fold higher than TM (0.44), whereas TMGN tumor: muscle ratio (97.5) is nearly 8-fold higher than TM (11.6). In conclusion, TMGN showed excellent tumor targeting and has promising prospects as a SPECT-radiopharmaceutical for imaging tumors.

Liquid Crystalline Nanoparticles for Nasal Delivery of Rosuvastatin: Implications on Therapeutic Efficacy in Management of Epilepsy.

In the present study we investigated the protective role of intranasal rosuvastatin liquid crystalline nanoparticles (Ros-LCNPs) against pentylenetetrazole (PTZ) induced seizures, increasing current electroshock (ICES) induced seizures, and PTZ-induced status epilepticus. From the dose titration study, it was evident that intranasal rosuvastatin (ROS), at lower dose, was more effective than oral and intraperitoneal ROS. The Ros-LCNPs equivalent to 5 mg/kg ROS were developed by hydrotrope method using glyceryl monooleate (GMO) as lipid phase. The high resolution TEM revealed that the formed Ros-LCNPs were cubic shaped and multivesicular with mean size of 219.15 ± 8.14 nm. The Ros-LCNPs showed entrapment efficiency of 70.30 ± 1.84% and release was found to be biphasic following Korsmeyer-Peppas kinetics. Intranasal Ros-LCNPs (5 mg/kg) showed significant increase in latency to PTZ-induced seizures and ICES seizure threshold compared to control and intranasal ROS solution. Additionally, intranasal Ros-LCNPs provided effective protection against PTZ-induced status epilepticus. No impairment in cognitive functions was observed following intranasal Ros-LCNPs. The results suggested that Ros-LCNPs could be an effective and promising therapeutics for the epilepsy management.

Parenteral Sustained Release Lipid Phase-Transition System of Ziprasidone: Fabrication and Evaluation for Schizophrenia Therapy.

INTRODUCTION: Ziprasidone (ZP) is a novel atypical antipsychotic agent effective in the treatment of positive and negative symptoms of schizophrenia with low chances for extrapyramidal side effects (EPs) and cognitive deficits. ZP possesses poor oral bioavailability (~50%), short biological half-life (~2.5 h) and due to extensive first-pass metabolism, a repeated dose is administered which makes the therapy non-adherent, leading to patient non-compliance. Therefore, this is a first report of developing parenteral ZP loaded sustained release phospholipid based phase-transition system (ZP-LPS). METHODS: The ZP-LPS system was formulated by mixing of biocompatible materials including phospholipid E 80, medium chain triglyceride (MCT) and ethanol. Optimization was done by aqueous titration method using pseudo-ternary phase diagram and dynamic rheological measurements. In vivo depot formation was confirmed by gamma scintigraphy after subcutaneous injection. Biodegradation and biocompatibility studies were performed for its safety evaluation. Finally, the efficacy of the formulation was assessed by Morris water maze (MWM) test and dizocilpine (MK-801) was used to induce schizophrenia in Sprague-Dawley rats. RESULTS: Optimized ZP-LPS showed rapid gelation (2 min), highest change in viscosity (~48000 mPa.s) and sustained release of ZP over a period of 1 month. Gamma scintigraphy depicted that the low-viscosity ZP-LPS system undergo rapid in situ gelation. Biodegradation and biocompatibility studies revealed gradual degradation in size of depot over a period of 28 days without any inflammation at the injection site. In MWM test, escape latency, time spent and total distance in target quadrant were significantly improved (p < 0.001) in the ZP-LPS group in comparison to the MK-801 group when evaluated at day 0, day 7 and day 28. However, significant improvement (p < 0.001) was observed only at day 0 in ZP suspension group. CONCLUSION: The overall result indicates that the novel ZP-LPS system is safe, biodegradable, and effective for the management of schizophrenia.

Improved cardioprotective effects of hesperidin solid lipid nanoparticles prepared by supercritical antisolvent technology.

Doxorubicin (DOX) is commonly used for the treatment of many types of cancers but its cardiotoxicity, owing to free radical formation, limits its clinical use. Hesperidin (HES), a flavanone glycoside, has been shown to exert multiple pharmacological actions including cardioprotective effects. Herein, we aim to formulate HES loaded solid lipid nanoparticles (SLNs) using supercritical antisolvent (SAS) technology to improve the oral delivery of HES. Process parameters were optimized to produce small size (175.3 ±â€¯3.6 nm) HES-SLNs with high encapsulation efficiency (87.6 ±â€¯3.8 %). DSC and XRD showed that HES is amorphously dispersed in SLNs. Compared to HES, HES-SLNs resulted in a nearly 20-fold increase in aqueous solubility and a nearly 5-fold increase in apparent permeability. Pharmacokinetics in rats revealed nearly 4.5-fold higher bioavailability of HES from SLN formulation compared to HES suspension. Data showed that HES-SLN significantly attenuated DOX-induced cardiotoxicity through lowering creatine kinase-muscle/brain, cardiac troponin I and improving histopathological scores as compared to the DOX group. HES-SLN also decreased malondialdehyde, increased catalase and superoxide dismutase of rats' heart to levels relatively comparable to control. Marked reductions in caspase-3 were also observed following HES-SLN treatment. Conclusively, these results describe a cardioprotective effect for HES-SLN against DOX-induced cardiotoxicity likely facilitated via suppression of oxidative stress and apoptosis.