Free TcO 4- in 99m Tc-PSMA Scan : A Case Report and Review of an Old Pitfall in the New Era of Modern Imaging.

ABSTRACT: In a recent 99m Tc-HYNIC-PSMA study conducted at our department, we examined 2 patients with prostate cancer referred for initial staging on the same day. The whole-body scans revealed radiotracer uptake in the gastric mucosa and thyroid glands, alluding to high levels of free TcO 4- in the injected vial. The scans were repeated after confirming acceptable radiopharmaceutical purity of 97% (normal range, 95%-100%). Interestingly, 1 patient had liver metastases at presentation, which remained non-PSMA-avid after repeating the scan. We have reviewed this pitfall, which has been reported with many radiotracers, yet not reported with PSMA tracers.

Development of a Novel Sulfur Quantum Dots: Synthesis, 99mTc Radiolabeling, and Biodistribution.

Sulfur quantum dots (SQDs) as free heavy metal element quantum dots have promising applications in diagnosis and therapy; however, SQDs' in vivo biodistribution has not been studied. In the current study, SQDs were synthesized directly from cheap sublimated sulfur powder via a one-pot solvothermal method, and sucrose was used as a stabilizer to enhance stability and biocompatibility. The as-obtained SQDs with an average size of 4.6 nm exhibited great water dispersity, highly favorable quantum yield (21.5%), and uniformly spherical shape which were confirmed by UV-Vis, fluorescence spectrophotometer, TEM, and FESEM/EDX/PSA analyses. Moreover, the as-synthesized SQDs had very low cytotoxicity based on cancer (C26) and normal (L929) cell lines via MTT assay. And also, SQDs were radio-labeled directly by Technetium-99m (99mTc), which had good stability ranging from 86 to 99% in PBS and human serum. The SQDs' cell uptake on C26 and L929 cell lines demonstrated that cancer cells had more uptake than normal cells by increasing concentrations. Moreover, SQDs' in vivo biodistribution results displayed high kidney dose accumulation and rapid renal clearance, making them suitable for imaging and therapeutic applications.

Docetaxel in combination with metformin enhances antitumour efficacy in metastatic breast carcinoma models: a promising cancer targeting based on PEGylated liposomes.

OBJECTIVES: Metformin has been shown to kill cancer stem-like cells in genetically various types of breast carcinoma. With the aim to simultaneously eradicate the bulk population of tumour cells and the rare population of cancer stem-like cells in breast cancer tissues, we used the combination chemotherapy of docetaxel (DTX) with metformin (MET). Furthermore, we introduce an active loading method based on ammonium sulphate 250 mM (SA) for encapsulating docetaxel into liposomes. METHODS: Docetaxel and metformin encapsulated into PEGylated liposomes with two different methods based on remote or passive loading methods, respectively. The size and surface charge of the liposomes were characterized. DTX content in the nanoliposomes was measured by the high-performance liquid chromatography method. The drug release profiles were evaluated in phosphate-buffered dextrose 5% with the pH of 6.5 and 7.4. We examined the antitumour activity of Taxotere (TAX), and liposomal formulation of DTX and MET as a monotherapy or combination therapy. The biodistribution of liposomes was also investigated using 99mTc hexamethyl propylene amine oxime method in BALB/c mice bearing 4T1 breast carcinoma tumours. KEY FINDINGS: The final formulations were prepared according to the best physicochemical characteristics which were HSPC/mPEG2000-DSPE/Chol (DTX liposomes) and HSPC/DPPG/mPEG2000-DSPE/Chol (MET liposomes), at molar ratios of 85/5/10 and (55/5/5/35), respectively. In vivo experiments showed that when free or liposomal metformin used in combination with liposomal docetaxel, they prolonged median survival time (MST) from 31 in the control group to 46 days, which demonstrates their promising effects on the survival of the 4T1 breast carcinoma mice models. Moreover, combination therapies could significantly increase life span in comparison with phosphate-buffered saline (PBS) and Taxotere groups at the same dose. Furthermore, in the combination therapy study, treatment with DTX liposomes prepared by ammonium sulphate 250 mM buffer alone resulted in similar therapeutic efficacy to combination therapy. The biodistribution study exhibited significant accumulation of DTX liposomes in the tumours due to the Enhanced Permeability and Retention effect. CONCLUSIONS: This study also showed that metformin-based combinatorial chemotherapies have superior efficacy versus their corresponding monotherapy counterparts at same doses. The findings confirm that liposomes based on ammonium sulphate 250 mM could be as a promising formulation for efficient DTX delivering and cancer targeting and therefore merit further investigations.

Sentinel lymph node mapping in post chemotherapy nonseminoma testicular cancer patients undergoing retroperitoneal lymph node dissection: A series of nine cases.

OBJECTIVES: Testicular germ cell cancers are the most common solid malignancy among young men at the age ranging between 14 and 35 years. In this study, we evaluated the feasibility of sentinel lymph node mapping using intraoperative injection of radiotracer in nonseminomatous testicular cancer patients with history of orchiectomy who were candidate for retroperitoneal lymph node dissection (RPLND) in post-chemotherapy setting. METHODS: Nine consecutive cases were included in the study. Technetium-99m-labelled phytate was injected in two divided doses in the stump of the spermatic cord, through transabdominal approach. A hand-held gamma probe was used for radio-guided retroperitoneal sentinel lymph node detection intraoperatively and confirming the location of the sentinel lymph nodes. RESULTS: Detection rate and the false negative rate were estimated as the main indices. The detection rate was 6/9 (66%) and the false negative rate was 0/2 (0%). Location of the dissected sentinel lymph nodes were interaortocaval (2 patients), internal iliac (1 patient), external iliac (1 patient), common iliac (2 patients), and paraaortic (1 patient). CONCLUSION: Sentinel lymph node mapping technique seems to be feasible and promising in post chemotherapy non-seminoma testis cancer patients who are candidate for RPLND; however, further larger studies are needed to increase and standardize the detection rate.

Sentinel lymph node biopsy in upper tract urothelial cancers: an experience with intraoperative radiotracer injection.

BACKGROUND: The feasibility of the sentinel node mapping in upper tract urothelial cancers (UTUC) was evaluated, using a radiotracer as the mapping material. MATERIAL AND METHODS: To identify the sentinel lymph nodes, 37 MBq of [99mTc] phytate was injected in five patients with the renal pelvis or ureter cancer, who were candidates for ureterectomy and lymphadenectomy. The radiotracer was injected in a peritumoral fashion following the surgical exposure of the tumour. The sentinel lymph nodes were detected using a handheld gamma probe. RESULTS: By intraoperatively injecting the radiotracer immediately after surgical exposure of the tumour, at least one sentinel lymph node could be detected in each patient, and the detection rate was 100%. The location of sentinel nodes was in the paracaval, renal hill, retro-aortic, para-aortic, common iliac, and external iliac areas, which was dependent on the tumour location. No false-negative case was identified. CONCLUSIONS: Sentinel node mapping is feasible in UTUC. Injection technique (intra-vesical approach vs peri-tumoral injection after exposure of the tumour) and location of the tumour (proximal vs distal) may affect the technique's feasibility.

Development of a stable and high loaded liposomal formulation of lapatinib with enhanced therapeutic effects for breast cancer in combination with Caelyx®: In vitro and in vivo evaluations.

Lapatinib, a dual tyrosine kinase inhibitor, has poor water solubility, which results in poor and incomplete absorption from the gastrointestinal tract. To overcome this obstacle, we designed a stable and high-loaded liposomal formulation encapsulating lapatinib and examined its therapeutic efficacy in vitro and in vivo on TUBO and 4T1 cell lines. We also assessed the impact of liposomal lapatinib on the extent of the tumor and spleen-infiltrating lymphocytes and the autophagy and apoptosis gene expression within the tumor site. Our results showed that liposomal lapatinib inhibits cell proliferation and significantly induces autophagy and apoptosis compared to control groups. Moreover, when it used in combination with liposomal doxorubicin, it extended the time to end from 22.4 ± 3.5 in the control group to 40 days in the TUBO cell line and from 29.2 ± 1.7 to 38.6 ± 2.2 days in 4T1 triple-negative breast cancer cell line, which reveals its promising effects on the survival of tumor-bearing mice. Our results indicated the need for further evaluations to understand liposomal lapatinib's potential effects on autophagy, apoptosis, and particularly on immune system cells.

Prognostic value and optimal threshold of first thyroglobulin in low/intermediate risk DTC.

BACKGROUND: The aim of this study was to define prognostic value and optimal threshold of first thyroglobulin (fTg) measured after thyroidectomy and just before radio-iodine therapy (RIT), in low/intermediate risk patients with differentiated thyroid cancer (DTC). METHODS: This is a retrospective study in 383 patients with DTC who were treated with surgery followed by RIT. Response to treatment was assessed 1 and 2 years after RIT. Odds ratio of different risk factors like age, sex, TNM stage, fTg and Anti-Tg Ab were compared between patients with and without incomplete response 1 and 2 years after treatment. Receiver operating curve analysis was used for definition of optimal fTg cut off for detection of incomplete response. RESULTS: 218 female and 55 male with DTC had negative anti-Tg antibody (mean age: 37.5±14.5 years) and analyzed separately. fTg≥33.5 ng/mL and fTg/TSH ratio of ≥0.36 had the optimal sensitivity and specificity for detection of incomplete response 1 and 2 years after treatment. fTg<33.5 ng/mL had NPV of 98.5% for exclusion of distant metastases. Patients with fTg≥33.5 ng/mL had longer "time to excellent response" (3.6±2.3 vs. 2.0±1.8 yrs) and needed more additional treatments compared to patients with fTg<33.5 ng/mL. Multivariate analysis showed that fTg was the most potent risk factor for prediction of treatment failure 1 and 2 years after RIT. CONCLUSIONS: fTg of ≥33.5 ng/mL was the most important risk factor for prediction of treatment failure after RIT and could be included in decision algorithms regarding intensity of treatments in low/intermediate risk patients with DTC.

Lymphoscintigraphy in the Time of COVID-19: Effect of Molybdenum-99 Shortage on Feasibility of Sentinel Node Mapping.

Background: In the current study, we reported our experience on sentinel node mapping of breast cancer patients during the extreme shortage of Mo99-Tc99m generators using Tc-99m phytate. Methods and Results: During the period from March 7, 2019, to April 18, 2020, due to disruption of molybdenum supply chain, we used low specific activity Tc-99m pertechnetate elute (0.5-2 mCi of 99mTcO4 in 5 mL) for each kit preparation. Two or three intradermal periareolar injections were done for each patient (0.02-0.1 mCi/0.2 mL for each injection). Immediately following injection, dynamic lymphoscintigraphy was done. Surgery was done the same day of injection and the axillary sentinel node was sought using a gamma probe. Overall, 35 patients were included in the study. The specific activity of the Tc-99m elute (in 5 mL) used for kit preparation was 2 mCi/10 mg in four, 1.5 mCi/10 mg in eight, 1.25 mCi/10 mg in eight, 1 mCi/10 mg in three, 0.75 mCi/10 mg in five, and 0.5 mCi/10 mg of 99mTc-Phytate in seven patients. For the first four groups of patients, we used two 0.2 mL injections, while in the latter two groups, three 0.2 mL injections were used. At least one sentinel node was detected in all patients but three in whom axilla was involved. Conclusion: Sentinel node biopsy can be achieved with low specific activity of Tc-99m elute at the time of Mo99-Tc-99m generator shortage. If special personal protection is used, sentinel node mapping can be done in nuclear medicine departments with excellent results despite the COVID-19 pandemic and disruption of generator shipment.

Sentinel lymph node biopsy in muscle-invasive bladder cancer: single-center experience.

OBJECTIVE: In this study, the validity of sentinel node biopsy procedure as our index test was assessed and compared with bilateral pelvic lymphadenectomy for staging and detecting the regional lymph nodes metastasis in patients with muscle-invasive bladder cancer (MIBC). METHODS: Consecutive series of cases with T1-T4 urothelial MIBC were included. Following the injection of radiotracer, sentinel nodes were sought using a handheld gamma probe and all hot nodes were harvested. Bilateral pelvic lymphadenectomy was done for all patients following sentinel node biopsy. The tumor specimen, sentinel nodes, and excised lymph nodes were evaluated histopathologically. Same as the other midline tumors, detection rate and false negative rates were calculated using patient basis and side basis methods. RESULTS: By evaluating each patient as a unit of analysis, sentinel nodes were detected in 35 of 41 patients (85%), 13/16 (81%) of the neoadjuvant chemotherapy (NAC) and 22/25 (88%) of the no-neoadjuvant chemotherapy (No-NAC) participants. The false negative rate was 3/7 (42%): 1/3 (33%) for NAC, and 2/4 (50%) for No-NAC patients. By evaluating each hemipelvis as a unit of analysis, sentinel nodes were detected in 53 of 82 hemipelves (65%), 19/32 (66%) of the NAC, and 34/50 (68%) of the No-NAC hemipelves. No false-negative result was found by assessing each hemipelvis as a unit of analysis. CONCLUSIONS: Sentinel node biopsy is a feasible method for lymph node staging in MIBC, including patients with a history of NAC. To optimize the sensitivity, the decision regarding the lymphadenectomy is best to be based on the pathological status of sentinel node harvested from each hemipelvis separately as the unilateral finding of a sentinel node, does not rule out the possibility of metastatic involvement of contralateral pelvic lymph nodes.

Folate targeted PEGylated liposomes for the oral delivery of insulin: In vitro and in vivo studies.

In this study using phospholipids with high transition temperature and taking advantage of PEGylation, we designed liposomal formulation targeted with folic acid (FA) to improve the stability of liposomes with high penetration efficiency at the same time. The results of characterization demonstrated that liposomal formulations are in range of 150-210 nm size with negative surface charge. The results of cell uptake indicated that FA conjugation resulted in the more uptake of insulin. However, the results of transepithelial electrical resistance (TEER) showed no statistical differences among the formulations. The results of biodistribution also demonstrated that PEGylated liposome targeted with FA had more residence time in stomach and intestine along with higher amounts in blood and liver. The anti-diabetic effects of formulation in vivo indicated the efficacy of PEGylated liposome targeted with FA had promising results in decreasing blood glucose and increasing insulin levels. The results of this study indicated that using phospholipids with high Tm along with PEGylation and using targeting ligand could improve efficiency of oral delivery of liposomes which merit further investigation.

Optimization of Docetaxel Loading Conditions in Liposomes: proposing potential products for metastatic breast carcinoma chemotherapy.

Docetaxel (DTX) was loaded in nanoliposomes based on a new remote loading method using mannitol and acetic acid as hydration buffer. DTX loading conditions were optimized, and the final formulations were prepared according to the best parameters which were HSPC/mPEG2000-DSPE/Chol (F1), HSPC/mPEG2000-DSPE/DPPG/Chol (F2), HSPC/mPEG2000-DSPE/DSPG/Chol (F3), at molar ratios of 85/5/10, 80/5/5/10, 80/5/5/10, respectively. DTX-liposomes were found of desired size (~115 nm) and homogeneity (PDI ≤ 0.2), high drug encapsulation efficacy (34-67%) and DTX concentration, and favorable stability. Passive loaded counterparts liposomes showed three times lower encapsulation efficacy compared to the remote loaded liposomes. The drug release of remote loaded liposomes in plasma 50% was significantly more controlled and less in comparison with their passive loaded counterparts (p < 0.0001). The IC50 values of formulations were determined on MCF-7, 4T1, TUBO, NIH/3T3 cell lines. The biodistribution of iodinated docetaxel as free or liposomal form exhibited significantly greater accumulation of DTX-liposomes in tumors than that of free docetaxel due to the EPR effect. In vivo experiment with BALB/c mice bearing 4T1 or TUBO breast carcinoma tumors also showed that DTX-liposomes could significantly delay tumor growth and prolonged the survival time in comparison with control and Taxotere groups at the similar dose of 8 mg/kg. F1 and F2 formulations were stable and showed good anti-tumor activity and merit further investigation.

Synthesis, 99mTc-radiolabeling, and biodistribution of new cellulose nanocrystals from Dorema kopetdaghens.

Cellulose nanocrystals (CNCs) are known as nano-biomaterials that can be achieved from the different sources. The designated CNCs have been successfully fabricated from the roots of Dorema kopetdaghens (Dk) plant by sulphuric acid hydrolysis method. Structural analysis has been carried out by the means of XRD, FTIR, and TGA/DTG procedures. The XRD results have indicated that the crystalline structure of CNCs had been cellulose I with the crystallinity index of 83.20% and size of 4.95 nm. The FTIR spectra have shown that the resulting samples have been related to the cellulose species. The thermal properties of CNCs have exhibited a lower thermal stability in comparison to the untreated roots. It has been indicated by the morphological analyses of FESEM, TEM, and AFM that the nanoparticles had contained a spherical shape. Also, the cytotoxicity of CNCs against A549 cell line has not exhibited any cytotoxic effects. The analysis of labeling efficiency in regards to 99mTc-CNCs has been observed to be above 98%, while the biodistribution of radioactivity has displayed a high uptake by the kidneys and blood circulation. Therefore, it is possible to transform the low-cost by-product into a beneficial substance such as CNCs that can be utilized in bioimaging applications.

Preparation, in vitro and in vivo evaluation of PLGA/Chitosan based nano-complex as a novel insulin delivery formulation.

The smart self-regulated drug delivery systems for insulin administration are desirable to achieve glycemic control, and decrease the long-term micro- and macro vascular complications. In this study, we developed an injectable nano-complex formulation for closed-loop insulin delivery after subcutaneous administration and release of insulin in response to increased blood glucose levels. The nano-complex was prepared by mixing oppositely charged chitosan and PLGA nanoparticles. PLGA nanoparticles were prepared using double-emulsion solvent diffusion method, and were loaded with glucose oxidase (GOx) and catalase (CAT) enzymes. These negatively charged particles decrease micro-environmental pH, by gluconic acid production in the glucose molecules presence. Positively charged chitosan nanoparticles were prepared using ionic gelation method, and were loaded with insulin. These nanoparticles (NPs) released insulin by dissociation in acidic pH caused by the GOx activity. Following in vitro studies, in vivo evaluation of nano-complex formulations in streptozocin induced diabetic rats showed significant glycemic regulation up to 98 h after subcutaneous administration.

Bio-based synthesis of Nano-Ceria and evaluation of its bio-distribution and biological properties.

Bio-based synthesis of Nano-Ceria (NC) was performed in Linum usitatissimum L. (Lu) seeds extract as capping agent. Obtained gel was calcined at 400, 500, and 600 °C to investigate the effect of temperature on the size and morphology of the particles. All samples had spherical morphology which their crystallite size was decreased in higher temperature. Products were characterized by TGA/DTA, UV-vis, FESEM, FTIR and XRD. The band gap of the prepared samples was calculated through Tauc plot in the range of 3.2-3.4 eV. The results of MTT assay confirmed that NC has been shown no significant toxicity on A549 cell line. 2',7'-dichlorofluorescin diacetate (DCFDA) was used to determine antioxidant properties of NC on A549 cell and the results showed that all concentrations of NC could reduce reactive oxygen species (ROS). NC was labeled with technetium (99mTc) for in vivo bio-distribution study in Wistar rat. Radiolabeled NC was stable in different environments of PBS buffer and human serum with radiochemical purity of more than 95% according to the instant thin layer chromatography (ITLC) method. DLS analysis showed radiolabeled particles had small size and pleasant colloidal stability. Bio-distribution of radiolabeled NC illustrated the highest accumulation in kidneys (1 h: 5.94 ±â€¯0.77%ID/g, 4 h: 10.95 ±â€¯5.99%ID/g, 24 h 7.94 ±â€¯0.36%ID/g). Moreover, low uptake of 99mTc-NC in stomach confirmed the in vivo stability of 99mTc-NC. Accordingly, NC could be a worthy candidate for biological purposes and in vivo studies.

Formulation and Optimization of a New Cationic Lipid-Modified PLGA Nanoparticle as Delivery System for Mycobacterium tuberculosis HspX/EsxS Fusion Protein: An Experimental Design.

Polymeric particles and liposomes are efficient tools to overcome the low immunogenicity of subunit vaccines. The aim of the present study was formulation and optimization of a new cationic lipid-modified PLGA nanoparticles (NPs) as a delivery system for Mycobacterium tuberculosis HspX/EsxS fusion protein. The cationic lipid-modified PLGA NPs containing HspX/EsxS fusion protein were prepared using a modified double emulsion solvent evaporation method. Scanning electron microscopy and dynamic light scattering (DLS) tools were used to determine physical properties of hybrid NPs. A multi-level full factorial design was used to evaluate the influence of two factors of PLGA:DDA weight ratio (w/w) and PVA concentration (%) on size, surface charge, polydispersity index, encapsulation efficiency and yield. Finally, the optimal formulation was achieved based on desired responses. Mathematical models were obtained to indicate the relation between the studied factors and responses. The DDA concentration showed an increasing effect on surface charge and also a decreasing effect on particle size, encapsulation efficiency and yield. Higher amounts of DDA increased surface charge of NPs; however, the size, encapsulation efficiency and yield were decreased. The influence of various concentrations of PVA on different physical characteristics of PLGA:DDA hybrid NPs was variable. The optimal formulation consisted of 0.91 (55:5, w/w) weight ratio of PLGA:DDA and 0.5% PVA. The hybrid NPs showed acceptable particle size distribution, strong positive surface charge, prolonged antigen release and good encapsulation efficiency in comparison to PLGA alone. However, further preclinical and clinical studies are needed.

Sentinel Node Biopsy in Urothelial Carcinoma of the Bladder: Systematic Review and Meta-Analysis.

OBJECTIVES: To determine the application of sentinel node biopsy in urothelial carcinoma of the bladder, we performed a systematic review and meta-analysis. METHODS: Pooled false negative rate and detection rate were presented using Meta-Disc (version 1.4), and comprehensive meta-analysis (version 2). Publication bias and heterogeneity were assessed using funnel plot, Cochrane Q test, and I2 index. RESULTS: The pooled detection rate was 91% (95% CI 87-93%) and pooled sensitivity was 79% (95% CI 0.69-0.86%). When the neoadjuvant chemotherapy group of patients was omitted, the pooled sensitivity changed to 82% (95% CI 74-88%), and the Cochrane Q and I2 statistics were 15.44 and 48.2%, respectively. The pooled sensitivity of studies that included > 50% of pT 3 or 4 patients was 70% (59-80), by omitting studies that enrolled > 50% of patients at pT stage of 3 or 4, the pooled sensitivity increased to 93% (81-98). CONCLUSIONS: Although the studies on SN biopsy of muscle invasive bladder cancer patients resulted in a high detection rate and sensitivity, further validated multicenter trials with larger sample size are essential to confirm the reliability and accuracy of this approach and obtain a standardized method. We showed that pT1 or pT2 bladder cancer patients with clinically negative lymph nodes are the most appropriated group for sentinel lymph node mapping.

Corrigendum to "Exosomes derived from TRAIL-engineered mesenchymal stem cells with effective anti-tumor activity in a mouse melanoma model" [International Journal of Pharmaceutics 549 (2018) 218-229].

Exosomes are biological nano-sized vesicles (~30-200 nm in diameter) that are produced by a wide range of cells and play several roles in cell-cell communications. These vesicles contain membrane and cytoplasmic components of producing cells. Mesenchymal stem cells (MSCs) are the ideal producer of exosomes. The secreted vesicles from MSCs are promising biological vehicles for cell-free therapy in regenerative medicine, cancer therapy and targeted delivery of therapeutic agents to the tumor cells. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a promising member of the TNF family with selective effect on cancerous cells. Recent evidences showed that the membrane TRAIL-armed exosomes possess anti-tumor activity. However, the effect of in vivo administration of TRAIL-armed exosomes has not been reported so far. In the current study, mesenchymal stem cells expressing TRAIL/GFP proteins were prepared with the help of a non-viral vector based on polyethylenimine 25 kDa. Then, exosomes containing TRAIL protein (Exo-TRAIL) were isolated from the supernatant of genetically engineered MSCs and characterized. Antitumor activity of both MSC-derived exosomes and Exo-TRAIL was investigated in vitro and in vivo in three models. The results indicated that the co-injection of both Exo-TRAIL and tumor cells delayed the tumor appearance. Besides, the tumor volume/weight was efficiently decreased in tumor bearing mice. Moreover, it was shown that multi-dose injections of Exo-TRAIL reduced the tumor size while single dose treatment with Exo-TRAIL did not show significant anti-tumor activity. To conclude, these results suggested that MSC-derived Exo-TRAIL has a potential capacity for cancer treatment.

Robust mucosal and systemic responses against HTLV-1 by delivery of multi-epitope vaccine in PLGA nanoparticles.

In this investigation, the immunogenicity of HTLV-1 fusion epitope-loaded PLGA nanoparticles (NPs) was assessed in the absence or presence of co-encapsulated CpG ODN adjuvant, in a mice model. For this purpose, the multi-epitope chimera including Tax, env, and gag immunodominant HTLV-1 epitopes was encapsulated in biodegradable PLGA NPs with or without CpG adjuvant. PLGA nanospheres produced by a double emulsion method had a size of <200 nm, and encapsulation efficiency of chimera antigen was 85%. The release profile of radiolabeled chimera indicated that only 17.4% and 20.1% of chimera were released from PLGA NPs without or with co-encapsulated CPG ODN during one month, respectively. The PLGA formulations significantly elevated titers of IgG1, IgG2a, and sIgA antibodies, as well as IL-10, and IFN-γ cytokines and also reduced the amount of TGF-ß1 production relative to the other vaccines. Additionally, co-delivery of chimera and CpG ODN in PLGA NPs significantly promoted cellular and mucosal responses compared to the incorporation of CpG and chimera antigen. In summary, these results revealed that the sustained release of chimera from PLGA as an efficient polymeric system elicited potent cell-mediated and mucosal immunity without inflammatory responses against HTLV-1. Therefore, the proper design of vaccine formulation and immunization strategy are crucial factors to construct an efficient vaccine.

Green synthesis of labeled CeO2 nanoparticles with 99mTc and its biodistribution evaluation in mice.

AIMS: The in vivo targeted diagnostic applications of biosynthetic Cerium oxide nanoparticles (CeO2-NPs), prepared by applying chitosan as a stabilizer, was explored by evaluating the cytotoxicity through MTT assay on WEHI 164 cell line, the Hemolytic activity of CeO2-NPs and biodistribution in rats. MAIN METHODS: The CeO2-NPs were characterized through the use of TGA/DTG, PXRD, FESEM, FTIR, and UV-Vis spectroscopy. The biodistribution of CeO2-NPs were determined by directly labeled nanoparticles with Technetium-99 m (99mTc) radioisotope (99mTc-CeO2-NPs). The labeling efficiency and stability of 99mTc-CeO2-NPs were also measured with Instant Thin Layer Chromatography (ITLC) method. The saturation study was investigated by 1 mCi of 99mTc-CeO2-NPs using different concentrations of WEHI 164 cells after 4 h of incubation. In vivo biodistribution study was performed by intravenous injection of 600 µCi/200 µL 99mTc-CeO2-NPs through rat's tail. KEY FINDINGS: CeO2-NPs seemed to have a low cytotoxic effect on WEHI 164 cell line and did not result in hemolysis. The biodistribution of CeO2-NPs has shown that a huge amount of 99mTc-CeO2-NPs was amassed in the living human organs, including liver, lung, spleen, stomach, and thyroid which shows the in vivo stability of the labeled conjugate. Herein, we have developed a facile, economical, and greener synthetic procedure applying Chitosan template. This green approach is comparable to conventional methods that utilize hazardous materials which are would be a suitable alternative to circumvent synthetic issues related to these materials. SIGNIFICANCE: The bio-applications of nano-sized CeO2-NPs were explored to find new horizon to use nanotechnology as the diagnostic tool.

Exosomes derived from TRAIL-engineered mesenchymal stem cells with effective anti-tumor activity in a mouse melanoma model.

Exosomes are biological nano-sized vesicles (~30-200 nm in diameter) that are produced by a wide range of cells and play several roles in cell-cell communications. These vesicles contain membrane and cytoplasmic components of producing cells. Mesenchymal stem cells (MSCs) are the ideal producer of exosomes. The secreted vesicles from MSCs are promising biological vehicles for cell-free therapy in regenerative medicine, cancer therapy and targeted delivery of therapeutic agents to the tumor cells. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a promising member of the TNF family with selective effect on cancerous cells. Recent evidences showed that the membrane TRAIL-armed exosomes possess anti-tumor activity. However, the effect of in vivo administration of TRAIL-armed exosomes has not been reported so far. In the current study, mesenchymal stem cells expressing TRAIL/GFP proteins were prepared with the help of a non-viral vector based on polyethylenimine 25 kDa. Then, exosomes containing TRAIL protein (Exo-TRAIL) were isolated from the supernatant of genetically engineered MSCs and characterized. Antitumor activity of both MSC-derived exosomes and Exo-TRAIL was investigated in vitro and in vivo in three models. The results indicated that the co-injection of both Exo-TRAIL and tumor cells delayed the tumor appearance. Besides, the tumor volume/weight was efficiently decreased in tumor bearing mice. Moreover, it was shown that multi-dose injections of Exo-TRAIL reduced the tumor size while single dose treatment with Exo-TRAIL did not show significant anti-tumor activity. To conclude, these results suggested that MSC-derived Exo-TRAIL has a potential capacity for cancer treatment. [corrected].