Delivery of Chlorambucil to the Brain Using Surface Modified Solid Lipid Nanoparticles.

The delivery of drugs to the brain in the therapy of diseases of the central nervous system (CNS) remains a continuing challenge because of the lack of delivery systems that can cross the blood-brain barrier (BBB). Therefore, there is a need to develop an innovative delivery method for the treatment of CNS diseases. Thus, we have investigated the interaction of γ-aminobutyric acid (GABA) and S-(-)-γ-amino-α-hydroxybutyric acid (GAHBA) with the GABA receptor by performing a docking study. Both GABA and GAHBA show comparable binding affinities toward the receptor. In this study, we developed surface-modified solid lipid nanoparticles (SLNs) using GAHBA-derived lipids that can cross the BBB. CLB-loaded SLNs were characterized by a number of methods including differential scanning calorimetry, dynamic light scattering, UV-vis spectroscopy, and transmission electron microscopy. The blank and CLB-loaded SLN suspensions were found to exhibit good storage stability. Also, the SLNs showed a higher encapsulation efficiency for CLB drugs. In vitro release kinetics of CLB at physiological temperature was also investigated. The results of the in vitro cell cytotoxicity assay and flow cytometry studies in the human glioma U87MG cell line and human prostate cancer PC3 cell line suggested a higher efficacy of the GAHBA-modified CLB-loaded SLNs in U87MG cells. The transcription level of GABA receptor expression in the target organ and cell line was analyzed by a reverse transcription polymerase chain reaction study. The in vivo biodistribution and brain uptake in C57BL6 mice and SPECT/CT imaging in Wistar rats investigated using 99mTc-labeled SLN and autoradiography suggest that the SLNs have an increasing brain uptake. We have demonstrated the delivery of the anticancer drug chlorambucil (CLB) to glioma.

ZnAl2O4:Er3+ Upconversion Nanophosphor for SPECT Imaging and Luminescence Modulation via Defect Engineering.

This work reports an "all-in-one" theranostic upconversion luminescence (UCL) system having potential for both diagnostic and therapeutic applications. Despite considerable efforts in designing upconversion nanoparticles (UCNPs) for multimodal imaging and tumor therapy, there are few reports investigating dual modality SPECT/optical imaging for theranostics. Especially, research focusing on in vivo biodistribution studies of intrinsically radiolabeled UCNPs after intravenous injection is of utmost importance for the potential clinical translation of such formulations. Here, we utilized the gamma emission from 169Er and 171Er radionuclides for the demonstration of radiolabeled ZnAl2O4:171/169Er3+ as a potent agent for dual-modality SPECT/optical imaging. No uptake of radio nanoformulation was detected in the skeleton after 4 h of administration, which evidenced the robust integrity of ZnAl2O4:169/171Er3+. Combining the therapeutics using the emission of ß- particulates from 169Er and 171Er will be promising for the radio-theranostic application of the synthesized ZnAl2O4:169/171Er3+ nanoformulation. Cell toxicity studies of ZnAl2O4:1%Er3+ nanoparticles were examined by an MTT assay in B16F10 mouse melanoma cell lines, which demonstrated good biocompatibility. In addition, we explored the mechanism of UCL modulation via defect engineering by Bi3+ codoping in the ZnAl2O4:Er3+ upconversion nanophosphor. The UCL color tuning was successfully achieved from the red to the green region as a function of Bi3+ codoping concentrations. Further, we tried to establish a correlation of UCL tuning with the intrinsic oxygen and cation vacancy defects as a function of Bi3+ codoping concentrations with the help of electron paramagnetic resonance (EPR) and positron annihilation lifetime spectroscopy (PALS) studies. This study contributes to building a bridge between nature of defects and UC luminescence that is crucial for the design of advanced UCNPs for theranostics.

Nuclear Localization Signal Enhances the Targeting and Therapeutic Efficacy of a Porphyrin-Based Molecular Cargo: A Systemic In Vitro and Ex Vivo Evaluation.

The objective of the present work was to evaluate the potential of a nuclear localization signal (NLS) toward facilitating intracellular delivery and enhancement in the therapeutic efficacy of the molecular cargo. Toward this, an in-house synthesized porphyrin derivative, namely, 5-carboxymethyelene-oxyphenyl-10,15,20-tris(4-methoxyphenyl) porphyrin (UTriMA), was utilized for conjugation with the NLS sequence [PKKKRKV]. The three compounds synthesized during the course of the present work, namely DOTA-Lys-NLS, DOTA-UTriMA-Lys-NLS, and DOTA-Lys-UTriMA, were evaluated for cellular toxicity in cancer cell lines (HT1080), wherein all exhibited minimal dark toxicity. However, during photocytotoxicity studies with DOTA-Lys-UTriMA and DOTA-UTriMA-Lys-NLS conjugates in the same cell line, the latter exhibited significantly higher light-dependent toxicity compared to the former. Furthermore, the photocytotoxicity for DOTA-UTriMA-Lys-NLS in a healthy cell line (WI26VA4) was found to be significantly lower than that observed in the cancer cells. Fluorescence cell imaging studies carried out in HT1080 cancer cells revealed intracellular accumulation for the NLS-conjugated porphyrin (DOTA-UTriMA-Lys-NLS), whereas unconjugated porphyrin (DOTA-Lys-UTriMA) failed to do so. To evaluate the radiotherapeutic effects of the synthesized conjugates, all three compounds were radiolabeled with 177Lu, a well-known therapeutic radionuclide with high radiochemical purity (>95%). During in vitro studies, the [177Lu]Lu-DOTA-UTriMA-Lys-NLS complex exhibited the highest cell binding as well as internalization among the three radiolabeled complexes. Biological distribution studies for the radiolabeled compounds were performed in a fibrosarcoma-bearing small animal model, wherein significantly higher accumulation and prolonged retention of [177Lu]Lu-DOTA-UTriMA-Lys-NLS (9.32 ± 1.27% IA/g at 24 h p.i.) in the tumorous lesion compared to [177Lu]Lu-UTriMA-Lys-DOTA (2.3 ± 0.13% IA/g at 24 h p.i.) and [177Lu]Lu-DOTA-Lys-NLS complexes (0.26 ± 0.17% IA/g at 24 h p.i.) were observed. The results of the biodistribution studies were further corroborated by recording serial SPECT-CT images of fibrosarcoma-bearing Swiss mice administered with [177Lu]Lu-DOTA-UTriMA-Lys-NLS at different time points. Tumor regression studies performed with [177Lu]Lu-DOTA-UTriMA-Lys-NLS in the same animal model with two different doses [250 µCi (9.25 MBq) and 500 µCi (18.5 MBq)] resulted in a significant reduction in tumor mass in the treated group of animals. The above results revealed a definite enhancement in the targeting ability of molecular cargo upon conjugation with NLS and hence indicated that this strategy may be helpful for the preparation of drug-NLS conjugates as multimodal agents.

Brachytherapy at the nanoscale with protein functionalized and intrinsically radiolabeled [169Yb]Yb2O3 nanoseeds.

PURPOSE: Classical brachytherapy of solid malignant tumors is an invasive procedure which often results in an uneven dose distribution, while requiring surgical removal of sealed radioactive seed sources after a certain period of time. To circumvent these issues, we report the synthesis of intrinsically radiolabeled and gum Arabic glycoprotein functionalized [169Yb]Yb2O3 nanoseeds as a novel nanoscale brachytherapy agent, which could directly be administered via intratumoral injection for tumor therapy. METHODS: 169Yb (T½ = 32 days) was produced by neutron irradiation of enriched (15.2% in 168Yb) Yb2O3 target in a nuclear reactor, radiochemically converted to [169Yb]YbCl3 and used for nanoparticle (NP) synthesis. Intrinsically radiolabeled NP were synthesized by controlled hydrolysis of Yb3+ ions in gum Arabic glycoprotein medium. In vivo SPECT/CT imaging, autoradiography, and biodistribution studies were performed after intratumoral injection of radiolabeled NP in B16F10 tumor bearing C57BL/6 mice. Systematic tumor regression studies and histopathological analyses were performed to demonstrate therapeutic efficacy in the same mice model. RESULTS: The nanoformulation was a clear solution having high colloidal and radiochemical stability. Uniform distribution and retention of the radiolabeled nanoformulation in the tumor mass were observed via SPECT/CT imaging and autoradiography studies. In a tumor regression study, tumor growth was significantly arrested with different doses of radiolabeled NP compared to the control and the best treatment effect was observed with ~ 27.8 MBq dose. In histopathological analysis, loss of mitotic cells was apparent in tumor tissue of treated groups, whereas no significant damage in kidney, lungs, and liver tissue morphology was observed. CONCLUSIONS: These results hold promise for nanoscale brachytherapy to become a clinically practical treatment modality for unresectable solid cancers.

Intricacies in the Preparation of Patient Doses of [177Lu]Lu-Rituximab and [177Lu]Lu-Trastuzumab Using Low Specific Activity [177Lu]LuCl3: Methodological Aspects.

The development of humanized monoclonal antibodies (MAbs) with Lutetium-177 ([177Lu]Lu3+) has brought a paradigm shift in the arena of targeted therapy of various cancers. [177Lu]Lu-DOTA-Rituximab and [177Lu]Lu-DOTA-Trastuzumab have gained prominence due to their improved therapeutic efficacy in the treatment of lymphoma and breast cancer. The clinical dose formulation of these radiolabeled MAbs, using low specific activity [177Lu]LuCl3, requires extensive optimization of the radiolabeling protocol. The present study merits the development of a single protocol which has been optimized for conjugation of Rituximab and Trastuzumab with p-NCS-benzyl-DOTA and further radiolabeling these immunoconjugates (ICs) with low specific activity [177Lu]LuCl3. Herein, we report a consistent and reproducible protocol for clinical dose formulations of [177Lu]Lu-DOTA-Rituximab and [177Lu]Lu-DOTA-Trastuzumab (~9.25 GBq each, equivalent to ~2 patient doses) with radiochemical yield (RCY) between 84 and 86% and radiochemical purities (RCP) >99%. The in vitro stabilities of both these radioimmunoconjugates (RICs) were retained up to 120 h post-radiolabeling, upon storage with L-ascorbic acid as stabilizer (concentration: ~ 220-240 µg/37MBq) at -20 °C. The ready-to-use formulation of clinical doses[177Lu]Lu-DOTA-Rituximab and [177Lu]Lu-DOTA-Trastuzumab has been successfully achieved by employing a single optimized protocol. While [177Lu]Lu-DOTA-Rituximab has exhibited a high degree of localization in retroperitoneal nodal mass of refractory lymphoma patient, high uptake of [177Lu]Lu-DOTA-Trastuzumab has been observed in metastatic breast carcinoma patient with multiple skeletal metastases.

Physicochemical Characterization, Stability, and In Vitro Evaluation of Curcumin-Loaded Solid Lipid Nanoparticles Prepared Using Biocompatible Synthetic Lipids.

Solid lipid nanoparticles (SLNs) are promising drug delivery vehicles for the delivery of various drugs, especially poorly water-soluble drugs. However, the aqueous stability, drug release, and biocompatibility of SLNs are some of the issues that need attention. In this work, curcumin-loaded SLNs were prepared, and morphology, particle size, and entrapment efficiency were studied. For this, two amino acid-derived lipids were developed. The effect of the polarity of the lipid head on the aqueous stability of the SLN dispersion was investigated. Based on the stability, particle size, and polydispersity, an optimum formulation was obtained. The curcumin entrapment efficiency of the SLNs was found to be greater than those reported in the literature. The entrapped curcumin, as well as curcumin-loaded SLN suspensions, exhibited improved storage stability. The in vitro release kinetics indicated an enhanced rate of drug release in the case of curcumin-loaded SLNs consisting of the lipid containing -OH groups at the lipid head. The pure lipid and the blank SLN were found to have no significant cytotoxicity, but curcumin and curcumin-loaded SLNs induced cell death in a concentration-dependent manner in both human prostatic adenocarcinoma PC3 cell line and human breast carcinoma MCF7 cell line. This study has proposed a potential semisynthetic lipid for the stable SLN suspension for the delivery of curcumin.

Synthesis and 177Lu Labeling of the First Retro Analog of the HER2-Targeting A9 Peptide: A Superior Variant.

The retro analog of the HER2-targeting A9 peptide was synthesized by coupling amino acids in a reverse fashion and switching the N-terminal in the original sequence of the L-A9 peptide (QDVNTAVAW) to the C-terminal in rL-A9 (WAVATNVDQ). Modification in the backbone resulted in higher conformational stability of the retro peptide as evident from CD spectra. Molecular docking analysis revealed a higher HER2 binding affinity of [177Lu]Lu-DOTA-rL-A9 than the original radiopeptide [177Lu]Lu-DOTA-L-A9. Enormously enhanced metabolic stability of the retro analog led to significant elevation in tumor uptake and retention. SPECT imaging studies corroborated biodistribution results demonstrating a remarkably higher tumor signal for [177Lu]Lu-DOTA-rL-A9. The presently studied retro probe has promising efficiency for clinical screening.

A robust lyophilized kit for convenient one-step formulation of [68Ga]Ga-DOTA-E-[c(RGDfK)]2 in hospital radiopharmacy for clinical PET imaging.

The present article describes the development of robust lyophilized kit for convenient formulation of [68Ga]Ga-DOTA-E-[c(RGDfK)]2 (E = glutamic acid, R = arginine, G = glycine, D = aspartic acid, f = phenylalanine, K = lysine) radiopharmaceutical for clinical use in non-invasive monitoring of malignancies overexpressing integrin αvß3 receptors. Five batches of the kit were prepared with optimized kit contents, all of which showed high 68Ga-radiolabeling yield (>98%). Pre-clinical evaluation of the [68Ga]Ga-radiotracer in SCID mice bearing FTC133 tumour exhibited significant accumulation in the tumor xenograft. Preliminary human clinical investigation carried out in a 60 year old male patient with metastatic lung cancer revealed high radiotracer uptake in the tumor along with satisfactory target to non-target contrast. The developed kit formulation also showed a long shelf-life of at least 12 months on storage at 0 °C. All these results point towards the promising attributes of the developed kit formulation for convenient preparation of [68Ga]Ga-DOTA-E-[c(RGDfK)]2 for routine clinical use.

[99mTc]Tc-HYNIC-RM2: A potential SPECT probe targeting GRPR expression in prostate cancers.

INTRODUCTION: Elevated density of gastrin releasing peptide receptors (GRPR) in prostate cancer has led to exploration of several radiolabeled peptides for imaging and staging of the disease. The GRPR antagonist peptide RM2 has been successfully conjugated with several chelators and radiolabeled with gallium-68. The goal of this study was to synthesize a 99mTc-labeled probe and investigate its potential for SPECT imaging of prostate cancer. Towards this HYNIC-RM2 peptide conjugate was synthesized, radiolabeled with 99mTc and evaluated in GRPR-positive PC3 tumor xenografts. METHODS: HYNIC-RM2 was manually synthesized by standard Fmoc solid phase strategy and radiolabeled with 99mTc. In vitro cell studies were performed in GRPR-positive human prostate carcinoma (PC3) cells. Metabolic stability studies of [99mTc]Tc-HYNIC-RM2 were performed in normal mice in the presence as well as absence of neutral endopeptidase (NEP) inhibitor, phosphoramidon (PA). Biodistribution and imaging studies of [99mTc]Tc-HYNIC-RM2 were performed in SCID mice bearing PC3-xenograft. RESULTS: [99mTc]Tc-HYNIC-RM2 exhibited high binding affinity in low nanomolar range (Kd = 1.83 ± 0.31 nM). Metabolic stability studies in mice indicated that in the absence of PA, radiolabeled peptide was about 65 % intact in the blood at 15 min p.i., whereas proportion of intact radiolabeled peptide was enhanced to 90 % on co-administration of PA. Biodistribution studies in PC3 tumor bearing mice demonstrated high tumor uptake (8.02 ± 0.9%ID/g and 6.13 ± 0.44%ID/g at 1 h and 3 h p.i.). Co-administration of PA with the radiolabeled peptide resulted in further enhancement of tumor uptake (14.24 ± 0.76 % ID/g and 11.71 ± 0.59%ID/g at 1 h and 3 h p.i.). SPECT/CT images of [99mTc]Tc-HYNIC-RM2 could clearly visualize the tumor. Significant (p < 0.001) reduction in the tumor uptake with a co-injected blocking dose of unlabeled peptide ascertained the GRPR specificity of [99mTc]Tc-HYNIC-RM2. CONCLUSION: Encouraging results obtained in biodistribution and imaging studies indicate the potential of [99mTc]Tc-HYNIC-RM2 for further exploration as GRPR targeting agent.

68Ga-Labeled Trastuzumab Fragments for ImmunoPET Imaging of Human Epidermal Growth Factor Receptor 2 Expression in Solid Cancers.

Background: Trastuzumab, the first humanized antibody approved for therapeutic use has shown promising results for the treatment of patients with human epidermal growth factor receptor 2 (HER2) positive cancers. The aim of this study was to formulate immunoPET agents based on trastuzumab fragments and demonstrate their potential for early diagnosis of HER2-positive tumors. Materials and Methods: F(ab')2 and F(ab') fragments of trastuzumab were prepared by enzymatic digestion and conjugated with chelator NOTA for labeling with 68Ga. For comparison, intact trastuzumab was also radiolabeled. In vitro stability, immunoreactivity, and binding affinity of radio formulations toward HER2 receptors were evaluated by performing in vitro studies in cancer cell lines. Biodistribution and PET imaging studies were performed in animal model bearing tumors. Results: 68Ga-NOTA-F(ab')-trastuzumab, 68Ga-NOTA-F(ab')2-trastuzumab, and 68Ga-NOTA-trastuzumab could be prepared with >98% radiochemical purity (% RCP) and were found to be stable when studied up to 4 h. In vitro binding studies revealed high affinity and specificity of formulations toward HER2 receptors. Specific tumor uptake of 68Ga-NOTA-F(ab')-trastuzumab and 68Ga-NOTA-F(ab')2-trastuzumab in HER2-positive tumors was observed in biodistribution and PET imaging studies. Conclusions: This study describes optimization of protocol for the formulation of 68Ga-NOTA-F(ab')-trastuzumab and 68Ga-NOTA-F(ab')2-trastuzumab for targeting HER2-overexpressing tumors. Further studies with these radioformulations are warranted to confirm their potential as immunoPET agents for management of HER2-positive breast and other solid tumors.

Synthesis and evaluation of [177 Lu]Lu-labeled porphyrin loaded PAMAM dendrimer: Impact on tumor uptake and pharmacokinetics.

The objective of the present work is to evaluate the ability of the radiolabeled PAMAM dendrimers (polyamidoamine) towards facilitating the delivery of an in-house synthesized porphyrin derivative in the tumorous lesions to evaluate their candidature for possible application in endo-radionuclide therapy. For this, PAMAM particles were conjugated with a porphyrin derivative namely, 5,10,15,20-tetrakis-(4-carboxymethyleneoxyphenyl)porphyrin (STAP), synthesized in-house following a two-step reaction. The average number of porphyrin molecules loaded per PAMAM particle was evaluated using ultraviolet-visible spectrophotometry and was found to be approximately 2. STAP conjugated PAMAM particles were further conjugated with p-NCS-benzyl-DOTA (subsequently referred as DOTA) to facilitate radiolabeling with 177 Lu. On an average, two p-NCS-benzyl-DOTA molecules were observed to be attached per PAMAM-STAP particle. DOTA-PAMAM-STAP conjugate was radiolabeled with 177 Lu with a final radiochemical purity of >95%, which was determined by paper chromatography using two different mobile phases viz. 0.1 M sodium citrate buffer (pH 5.0) and 10 mM DTPA. Biological behavior of [177 Lu]Lu-DOTA-PAMAM-STAP conjugate was investigated in fibrosarcoma bearing Swiss mice model wherein accumulation of radiolabeled particles was observed in liver, GIT, spleen, and kidneys at 3 h post-administration. However, accumulated activity exhibited rapid clearance from majority of the organs at 24 h post-administration. [177 Lu]Lu-DOTA-PAMAM-STAP conjugate exhibited an appreciable uptake in tumor mass [6.09 ± 1.22 percentage injected activity/organ (% IA/organ)] at 3 h post-administration (p.i.) which was found to reduce to 1.05 ± 0.13 % IA/organ at 24 h post-administration. The results obtained in biodistribution studies were further corroborated through scintigraphic imaging performed in the same animal model. Despite of an appreciable accumulation in tumor mass, the lower retention of the [177 Lu]Lu-DOTA-PAMAM-STAP conjugate therein, at longer time point (24 h p.i.) may limit its possible potential as a radio-therapeutic agent and indicates towards need for further structural manoeuvring to attain favorable in vivo performance.

A Study on FibroScan and Endoscopic Finding in Patients of Chronic Liver Disease attending Tripura Medical College and Dr. B.R. Ambedkar Memorial Teaching Hospital.

INTRODUCTION: Chronic liver disease (CLD) represents different liver disorders of varying severity and etiology in which hepatic inflammation and fibrosis continue at least for 6 months. Portal hypertension is one of the important complications of CLD and its early recognition is of paramount importance. Though liver biopsy remains the gold standard for diagnosing liver fibrosis and upper gastrointestinal (GI) endoscopy plays an important role in diagnosing different findings of portal hypertension, various noninvasive methods like FibroScan are being increasingly used to diagnose liver fibrosis. AIMS AND OBJECTIVES: Study the FibroScan and endoscopic findings in patients of CLDs and the objectives are to find the prevalence of portal hypertension and to find various grades of esophageal varix and portal hypertensive gastropathy (PHG) and its relationship with liver fibrosis by FibroScan. MATERIALS AND METHODS: A total of 114 patients of CLD and compensated cirrhosis having childturcotte- pugh (CTP) stages A and B were included in the study fulfilling inclusion and exclusion criteria, after calculating the sample size of 100. All the patients underwent detailed history, physical and gastrointestinal examination. Complete blood count (CBC), liver function test (LFT), kidney function test (KFT), viral markers were done. Aspartate aminotransferase (AST) to platelet ratio index (APRI) score was calculated, liver fibrosis was estimated by FibroScan and evidence of portal hypertension was documented by upper GI endoscopy. Cutoff value of FibroScan, APRI score, and model for end-stage liver disease (MELD) score for portal hypertension was decided by receiver operating characteristic (ROC) curve. RESULTS: Alcoholic liver disease (ALD) was the most common cause (43%) of CLD closely followed by nonalcoholic fatty liver disease (NAFLD) in 42% cases followed by chronic viral hepatitis, 75% patients had evidence of portal hypertension with PHG being the most common followed by esophageal varix. F4 fibrosis was found in 73% of cases followed by F3, F2, and F1 fibrosis. FibroScan value of 12.2 kPa was predictive of presence of portal hypertension and value of 26.6 mm predicted the presence of large esophageal varices.

Clinical Dose Preparation of [177Lu]Lu-DOTA-Pertuzumab Using Medium Specific Activity [177Lu]LuCl3 for Radioimmunotherapy of Breast and Epithelial Ovarian Cancers, with HER2 Receptor Overexpression.

Background: The overexpression of human epidermal growth factor receptor 2 (HER2) is commonly associated with metastatic breast cancer and epithelial ovarian cancer. The U.S. Food and Drug Administration (FDA) has approved Trastuzumab as an anti-HER2 agent for the metastatic breast and epithelial ovarian cancer. However, Trastuzumab has severe limitations in the treatment of metastatic breast cancer associated with ligand-dependent dimerization of HER2 receptor at the extracellular domain-II (ECD-II) region. The therapeutic approach in combination of pertuzumab and trastuzumab is found to be effective in preventing HER2 dimerization at the ECD-II region. The radioimmunotherapeutic approach, utilizing both these anti-HER2 agents (trastuzumab/pertuzumab), radiolabeled with [177Lu]Lu3+, has proved to be clinically efficacious with promising potential. Toward this, the formulation for clinical doses of [177Lu]Lu-DOTA-pertuzumab has been optimized using medium specific activity (0.81 GBq/µg) [177Lu]LuCl3. Materials and Methods: Preconcentrated pertuzumab was conjugated with p-NCS-benzyl-DOTA. Purified DOTA-benzyl-pertuzumab conjugate was radiolabeled with carrier-added [177Lu]LuCl3. Quality control parameters were evaluated for the [177Lu]Lu-DOTA-pertuzumab. In vivo biodistribution was carried out at different time points postadministration. Specific cell binding, immunoreactivity, and internalization were investigated by using SKOV3 and SKBR3 cells. Results: In this study, the authors reported a consistent and reproducible protocol for clinical dose formulations of [177Lu]Lu-DOTA-pertuzumab, with a radiochemical yield of 86.67% ± 1.03% and radiochemical purity (RCP) of 99.36% ± 0.36% (n = 10). Preclinical cell binding studies of [177Lu]Lu-DOTA-pertuzumab revealed specific binding with SKOV3 and SKBR3 cells up to 24.4% ± 1.4% and 23.2% ± 0.8%, respectively. The uptakes in SKOV3- and SKBR3-xenografted tumor in severe combined immunodeficiency mice were observed to be 25.9% ± 0.8% and 25.2% ± 1.2% ID/g at 48 and 120 h postinjection, respectively. Conclusions: A protocol was optimized for the preparation of ready-to-use clinical dose of [177Lu]Lu-DOTA-pertuzumab, in hospital radiopharmacy settings. The retention of RCP of the radiopharmaceutical, on storage in saline and serum, at -20°C, up to 120 h postradiolabeling, confirmed its in vitro stability.

Automated radiochemical synthesis of pharmaceutical grade [18 F]FLT using 3-N-Boc-5'-O-dimethoxytrityl-3'-O-nosyl-thymidine precursor and its Sep-Pak® purification employing selective elution from reversed phase.

Pharmaceutical grade 3'-deoxy-3'-[18 F]fluorothymidine [18 F]FLT was synthesized using 3-N-Boc-5'-O-dimethoxytrityl-3'-O-nosyl-thymidine (BOC-Nosyl) precursor, in the general purpose TRACERlab FX modules. Purification of [18 F]FLT, via solid phase extraction (SPE) after radiosynthesis, using a combination of different SPE cartridges, yielded satisfactory results, with radiochemical and chemical purity >99%. While the non-decay corrected radiochemical yield (RCY) with 20 mg (24 µmole) of BOC-Nosyl precursor was found to be 6.80 ± 0.16%, the decay corrected radiochemical yield (RCY) was 9.95 ± 0.24%. Residual acetone, acetonitrile, and ethanol levels were found to be 22.97 ± 0.76, 109.08 ± 0.93, and 7,666.45 ± 3.7 ppm, respectively. A simplified method for solid-phase purification of [18 F]FLT was developed, circumventing the need for HPLC purification. Biodistribution in C57BL/6 mice with B16F10 cell line-induced melanoma showed tumor to blood ratio of ~3.8 at 90 min. PET/CT imaging of normal rabbit injected with [18 F]FLT shows selective uptake in the bone marrow and small intestine. [18 F]FLT was found to be excreted through the kidneys and get collected in the urinary bladder, 120 min post injection. PET/CT imaging performed in rabbit model at 30, 60, 90, and 120 min post [18 F]FLT injections showed concordance with tissue distribution kinetics of mice tumor model.

Psychosocial perception of health-care workers in a COVID-19-designated hospital in eastern India.

BACKGROUND: COVID-19 pandemic has changed the life of people in many facets, economic, social, and psychological. Frontline health-care workers (HCWs) fighting against this pandemic faced some psychological as well as social issues which are of major concern. The objective of the study is to evaluate the magnitude of mental health problems, namely depression, anxiety, and stress among frontline HCWs as well as their perception on ongoing events and surroundings. MATERIALS AND METHODS: It was a prospective, observational study on n = 85 HCWs over a 4-month period. Study participants were sampled purposively in accordance with inclusion and exclusion criteria; data were collected by online survey method. A semi-structured scale was used: Part A of which assessed the demography and perception of HCWs on surrounding along with ongoing social events and Part B consisted of the Depression, Anxiety, and Stress Scale-21 that was used to assess mental health issues. All the associations were tested in percentages and proportions. Statistics was calculated by using SPSS 24th version. RESULTS: Majority of the participants were female doctors and belonged to 21-30 years' age group. Most of them were marginally worried of contacting infection (73%) but were substantially apprehensive of transmitting infection to their family (56.5%) and hoped positive outcome ultimately in the form of recovery from infection. Majority (96.4%) gathered information from authentic sources and were confident of adequacy of their knowledge. Majority (88.3%) were satisfied about their occupational safety and responded on scientific solution of pandemic. However, we got a mixed result about their professional appreciation. Depression symptom score was higher than anxiety and stress symptom score in our participants. CONCLUSIONS: Doctors and nurses both were suffering from mental health issues, and provision of adequate information and occupational safety may lessen these burdens.

Therapeutic Multidose Preparation of a Ready-to-Use 177Lu-PSMA-617 Using Carrier Added Lutetium-177 in a Hospital Radiopharmacy and Its Clinical Efficacy.

Introduction: [177Lu]Lu-prostate-specific membrane antigen (PSMA)-617 has emerged as a promising radiopharmaceutical for targeting PSMA in metastatic castrate-resistant prostate carcinoma (mCRPC). We have optimized the radiolabeling protocol for a multidose formulation (27-28.8 GBq equivalent to 6-7 patient-doses) of [177Lu]Lu-PSMA-617 using [177Lu]Lu3+ produced via 176Lu(n,γ)177Lu route with moderate specific activity (0.66-0.81 GBq/µg). Methods: [177Lu]Lu-PSMA-617 was synthesized using moderate specific activity [177Lu]LuCl3 (0.74 GBq/µg) with PSMA-617 having metal-to-ligand molar ratio ∼1: 2.5 in CH3COONH4 buffer (0.1 M) containing gentisic acid at pH 4.0-4.5. Human prostate carcinoma cell line LNCaP cell (high PSMA expression) was used for in vitro cell-binding studies and generating tumor xenograft models in nude mice for tissue biodistribution studies. Several batches of the present formulation have been clinically administered in mCRPC patients (single patient dose: 4.44-5.55 GBq per cycle). Results: In this study we report a consistent and reproducible protocol for multidose formulations of [177Lu]Lu-PSMA-617 for adopting in a hospital radiopharmacy setting. Although the radiochemical yield of [177Lu]Lu-PSMA-617 was found to be 97.30% ± 1.03%, the radiochemical purity was 98.24% ± 0.50% (n = 19). In vitro and serum stability of [177Lu]Lu-PSMA-617 was retained up to 72 and 120 h after radiolabeling and upon storage at -20°C with a radioactive concentration between 0.37 and 0.74 GBq/mL upon using stabilizer concentration as low as 43-48 µg/mCi. Preclinical cell-binding studies of [177Lu]Lu-PSMA-617 revealed specific binding with LNCaP cells of 17.4% ± 2.4%. The uptake in LnCaP xenografted tumor (nude mice) was 7.5 ± 2.6% ID/g for ∼1.5-2.0 cm3 tumor volume at 24-h post-injection. Post-therapy (24 h) SPECT image of mCRPC patients with prior orchidectomy and various hormone therapy showed specific localization of [177Lu]Lu-PSMA-617 in the tumor region. Conclusions: Formulation of a ready-to-use multidose formulation of [177Lu]Lu-PSMA-617 was successfully achieved and the procedure was optimized for routine preparation at a hospital radiopharmacy set-up. High degree of localization of [177Lu]Lu-PSMA-617 in post-therapy SPECT scan and the post-therapeutic response confirms its therapeutic efficacy. Clinical Trials.gov ID: RPC/51/Minutes/Final dated 16th October, 2019.

On the Separation of Yttrium-90 from High-Level Liquid Waste: Purification to Clinical-Grade Radiochemical Precursor, Clinical Translation in Formulation of 90Y-DOTATATE Patient Dose.

Introduction: The quality control parameters of in-house-produced 90Y-Acetate from high-level liquid waste (HLLW) using supported liquid membrane (SLM) technology were validated and compared with the pharmacopeia standard. The radiolabeling of DOTATATE yielding 90Y-DOTATATE in acceptable radiochemical purity (RCP), with expected pharmacological behavior in in vivo models, establish the quality of 90Y-Acetate. Clinical translation of 90Y-Acetate in formulation of 90Y-DOTATATE adds support toward its use as clinical-grade radiochemical. Methods: Quality control parameters of 90Y-Acetate, namely radionuclide purity (RNP), were evaluated using ß- spectrometry, γ-spectroscopy, and liquid scintillation counting. RCP and metallic impurities were established using high-performance liquid chromatography and inductively coupled plasma optical emission spectrometry, respectively. The suitability of 90Y-Acetate as an active pharmaceutical ingredient radiochemical was ascertained by radiolabeling with DOTATATE. In vivo biodistribution of 90Y-DOTATATE was carried out in nude mice bearing AR42J xenografted tumor. Clinical efficacy of 90Y-DOTATATE was established after using in patients with large-volume neuroendocrine tumors (NET). Bremsstrahlung imaging was carried out in dual-head gamma camera with a wide energy window setting (100-250 keV). Results: In-house-produced 90Y-Acetate was clear, colorless, and radioactive concentration (RAC) in the range of 40-50 mCi/mL. RCP was >98%. 90Sr content was <0.85 µCi/Ci of 90Y. Gross λ content was <0.8 nCi/Ci of 90Y and no γ peak was observed. Fe3+, Cu2+, Zn2+, Cd2+, and Pb2+ contents were <1.7 µg/Ci. The radiolabeling yield (RLY) of 90Y-DOTATATE was >94%, RCP was >98%. The in vitro stability of 90Y-DOTATATE was up to 72 h postradiolabeling, upon storage at -20°C. Post-therapy (24 h) Bremsstrahlung image of patients with large NET exhibit complete localization of 90Y-DOTATATE in tumor region. Conclusions: This study demonstrates that the in-house-produced 90Y-Acetate from HLLW can be used for the formulation of various therapeutic 90Y-based radiopharmaceuticals. Since 90Y is an imported radiochemical precursor available at a high cost in India, this study which demonstrates the suitability of indigenously sourced 90Y, ideally exemplifies the recovery of "wealth from waste." The Clinical Trial Registration number: (P17/FEB/2019).