61Cu-PSMA-Targeted PET for Prostate Cancer: From Radiotracer Development to First-in-Human Imaging.

The demand for PET tracers that target prostate-specific membrane antigen (PSMA) continues to increase. Meeting this demand with approved 68Ga- and 18F-labeled PSMA tracers is challenging outside of major urban centers. This is because the short physical half-life of these radionuclides makes it necessary to produce them near their sites of usage. To overcome this challenge, we propose cyclotron-produced 61Cu for labeling PSMA PET tracers. 61Cu can be produced on a large scale, and its 3.33-h half-life allows shipping over considerably longer distances than possible for 68Ga and 18F. Production of true theranostic twins using 61Cu and the ß--emitter 67Cu is also feasible. Methods: PSMA-I&T (DOTAGA-(l-y)fk(sub-KuE)) and its derivative in which the DOTAGA chelator was replaced by NODAGA (NODAGA-(l-y)fk(sub-KuE)), herein reported as DOTAGA-PSMA-I&T and NODAGA-PSMA-I&T, respectively, were labeled with 61Cu and compared with [68Ga]Ga-DOTAGA-PSMA-I&T, [68Ga]Ga-NODAGA-PSMA-I&T, [68Ga]Ga-PSMA-11, and [18F]PSMA-1007. In vitro (lipophilicity, affinity, cellular uptake, and distribution) and in vivo (PET/CT, biodistribution, and stability) studies were performed in LNCaP cells and xenografts. Human dosimetry estimates were calculated for [61Cu]Cu-NODAGA-PSMA-I&T. First-in-human imaging with [61Cu]Cu-NODAGA-PSMA-I&T was performed in a patient with metastatic prostate cancer. Results: [61Cu]Cu-DOTAGA-PSMA-I&T and [61Cu]Cu-NODAGA-PSMA-I&T were synthesized with radiochemical purity of more than 97%, at an apparent molar activity of 24 MBq/nmol, without purification after labeling. In vitro, natural Cu (natCu)-DOTAGA-PSMA-I&T and natCu-NODAGA-PSMA-I&T showed high affinity for PSMA (inhibitory concentration of 50%, 11.2 ± 2.3 and 9.3 ± 1.8 nM, respectively), although lower than the reference natGa-PSMA-11 (inhibitory concentration of 50%, 2.4 ± 0.4 nM). Their cellular uptake and distribution were comparable to those of [68Ga]Ga-PSMA-11. In vivo, [61Cu]Cu-NODAGA-PSMA-I&T showed significantly lower uptake in nontargeted tissues than [61Cu]Cu-DOTAGA-PSMA-I&T and higher tumor uptake (14.0 ± 5.0 percentage injected activity per gram of tissue [%IA/g]) than [61Cu]Cu-DOTAGA-PSMA-I&T (6.06 ± 0.25 %IA/g, P = 0.0059), [68Ga]Ga-PSMA-11 (10.2 ± 1.5 %IA/g, P = 0.0972), and [18F]PSMA-1007 (9.70 ± 2.57 %IA/g, P = 0.080) at 1 h after injection. Tumor uptake was also higher for [61Cu]Cu-NODAGA-PSMA-I&T at 4 h after injection (10.7 ± 3.3 %IA/g) than for [61Cu]Cu-DOTAGA-PSMA-I&T (4.88 ± 0.63 %IA/g, P = 0.0014) and [18F]PSMA-1007 (6.28 ± 2.19 %IA/g, P = 0.0145). Tumor-to-nontumor ratios of [61Cu]Cu-NODAGA-PSMA-I&T were superior to those of [61Cu]Cu-DOTAGA-PSMA-I&T and comparable to those of [68Ga]Ga-PSMA-11 and [18F]PSMA-1007 at 1 h after injection and increased significantly between 1 and 4 h after injection in most cases. Human dosimetry estimates for [61Cu]Cu-NODAGA-PSMA-I&T were similar to the ones reported for 18F-PSMA ligands. First-in-human imaging demonstrated multifocal osseous and hepatic metastases. Conclusion: [61Cu]Cu-NODAGA-PSMA-I&T is a promising PSMA radiotracer that compares favorably with [68Ga]Ga-PSMA-11 and [18F]PSMA-1007, while allowing delayed imaging.

CUDC-907, a dual PI3K/histone deacetylase inhibitor, increases meta-iodobenzylguanidine uptake (123/131I-mIBG) in vitro and in vivo: a promising candidate for advancing theranostics in neuroendocrine tumors.

BACKGROUND: Neuroblastoma (NB) and pheochromocytoma/paraganglioma (PHEO/PGL) are neuroendocrine tumors. Imaging of these neoplasms is performed by scintigraphy after injection of radiolabeled meta-iodobenzylguanidine (mIBG), a norepinephrine analog taken up by tumoral cells through monoamine transporters. The pharmacological induction of these transporters is a promising approach to improve the imaging and therapy (theranostics) of these tumors. METHODS: Transporters involved in mIBG internalization were identified by using transfected Human Embryonic Kidney (HEK) cells. Histone deacetylase inhibitors (HDACi) and inhibitors of the PI3K/AKT/mTOR pathway were tested in cell lines to study their effect on mIBG internalization. Studies in xenografted mice were performed to assess the effect of the most promising HDACi on 123I-mIBG uptake. RESULTS: Transfected HEK cells demonstrated that the norepinephrine and dopamine transporter (NET and DAT) avidly internalizes mIBG. Sodium-4-phenylbutyrate (an HDACi), CUDC-907 (a dual HDACi and PI3K inhibitor), BGT226 (a PI3K inhibitor) and VS-5584 and rapamycin (two inhibitors of mTOR) increased mIBG internalization in a neuroblastoma cell line (IGR-NB8) by 2.9-, 2.1-, 2.5-, 1.5- and 1.3-fold, respectively, compared with untreated cells. CUDC-907 also increased mIBG internalization in two other NB cell lines and in one PHEO cell line. We demonstrated that mIBG internalization occurs primarily through the NET. In xenografted mice with IGR-NB8 cells, oral treatment with 5 mg/kg of CUDC-907 increased the tumor uptake of 123I-mIBG by 2.3- and 1.9-fold at 4 and 24 h post-injection, respectively, compared to the untreated group. CONCLUSIONS: Upregulation of the NET by CUDC-907 lead to a better internalization of mIBG in vitro and in vivo.

Head-to-head comparison of different classes of FAP radioligands designed to increase tumor residence time: monomer, dimer, albumin binders, and small molecules vs peptides.

PURPOSE: Fibroblast activation protein-α (FAP)-targeting radioligands have recently demonstrated high diagnostic potential. However, their therapeutic value is impaired by the short tumor residence time. Several strategies have been tested to overcome this limitation, but a head-to-head comparison has never been done. With the aim to identify strengths and limitations of the suggested strategies, we compared the monomer FAPI-46 versus (a) its dimer (FAPI-46-F1D), (b) two albumin binders conjugates (FAPI-46-Ibu (ibuprofen) and FAPI-46-EB (Evans Blue)), and (c) cyclic peptide FAP-2286. METHODS: 177Lu-labeled ligands were evaluated in vitro in cell lines with low (HT-1080.hFAP) and high (HEK-293.hFAP) humanFAP expression. SPECT/CT imaging and biodistribution studies were conducted in HT-1080.hFAP and HEK-293.hFAP xenografts. The areas under the curve (AUC) of the tumor uptake and tumor-to-critical-organs ratios and the absorbed doses were estimated. RESULTS: Radioligands showed IC50 in the picomolar range. Striking differences were observed in vivo regarding tumor uptake, residence, specificity, and total body distribution. All [177Lu]Lu-FAPI-46-based radioligands showed similar uptake between the two tumor models. [177Lu]Lu-FAP-2286 showed higher uptake in HEK-293.hFAP and the least background. The AUC of the tumor uptake and absorbed dose was higher for [177Lu]Lu-FAPI-46-F1D and the two albumin binder conjugates, [177Lu]Lu-FAPI-46-Ibu and [177Lu]Lu-FAPI-46-EB, in HT1080.hFAP xenografts and for [177Lu]Lu-FAPI-46-EB and [177Lu]Lu-FAP-2286 in HEK293.hFAP xenografts. The tumor-to-critical-organs AUC values and the absorbed doses were in favor of [177Lu]Lu-FAP-2286, but tumor-to-kidneys. CONCLUSION: The study indicated dimerization and cyclic peptide structures as promising strategies for prolonging tumor residence time, sparing healthy tissues. Albumin binding strategy outcome depended on the albumin binding moiety. The peptide showed advantages in terms of tumor-to-background ratios, besides tumor-to-kidneys, but its tumor uptake was FAP expression-dependent.

Development of a New Class of CXCR4-Targeting Radioligands Based on the Endogenous Antagonist EPI-X4 for Oncological Applications.

The peptide fragment of human serum albumin that was identified as an inhibitor of C-X-C motif chemokine receptor 4 (CXCR4), termed EPI-X4, was investigated as a scaffold for the development of CXCR4-targeting radio-theragnostics. Derivatives of its truncated version JM#21 (ILRWSRKLPCVS) were conjugated to 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) and tested in Jurkat and Ghost-CXCR4 cells. Ligand-1, -2, -5, -6, -7, -8, and -9 were selected for radiolabeling. Molecular modeling indicated that 177Lu-DOTA incorporation C-terminally did not interfere with the CXCR4 binding. Lipophilicity, in vitro plasma stability, and cellular uptake hinted 177Lu-7 as superior. In Jurkat xenografts, all radioligands showed >90% washout from the body within an hour, with the exception of 177Lu-7 and 177Lu-9. 177Lu-7 demonstrated best CXCR4-tumor targeting. Ex vivo biodistribution and single-photon emission computed tomography (SPECT)/positron emission tomography (PET)/CT imaging of 177Lu-7/68Ga-7 showed the same distribution profile for both radioligands, characterized by very low uptake in all nontargeted organs except the kidneys. The data support the feasibility of CXCR4-targeting with EPI-X4-based radioligands and designate ligand-7 as a lead candidate for further optimization.

Inhibitory potential of iRGD peptide-conjugated garcinol-loaded biodegradable nanoparticles in rat colorectal carcinoma.

Targeted drug delivery has become attention in chemotherapy during the last decade. The principle of chemotherapy seeks maximum effect to the desired site and the minimum impact to other undesired sites of action. The nanoparticulated drug delivery system progressed a lot in this aspect in the last twenty years. Plant-derived natural products and their semisynthetic analogues boosted chemotherapy through their excellent mechanistic approach to killing cancer cells. Keeping in mind the available molecular targets in colorectal carcinoma (CRC), in this article, we proposed a peptide conjugated novel polymeric nanoparticle to deliver garcinol against colorectal carcinoma. Integrin binding peptide iRGD, sequence c(CRGDKGPDC), has been selected as a targeting moiety, as most CRC overexpress integrins. We encapsulated garcinol in biodegradable polymeric nanoparticle (PLGA)-conjugated with iRGD peptide on the particles' surface, and analyzed its (iRGD-GAR-NP's) in vitro and in vivo antineoplastic potential against CRC in a comparative way with gracinol (GAR) and garcinol-loaded PLGA nanoparticles (GAR-NP). In vitro cellular studies on human CRC cell lines, HCT116 and HT-29, revealed the superior cytotoxic potential of iRGD-GAR-NP over GAR and GAR-NP. The IC50 value on HCT116 cells was reduced by 2.3 times compared to GAR upon the application of iRGD-GAR-NP. At equivalent doses, iRGD-GAR-NP induced higher apoptosis in HCT116 cells and caused blockage of cell cycle at G0/G1 phase of the same. iRGD-GAR-NP increased the apoptotic population of HCT116 cells by 2.5 times compared to GAR. In vivo biodistribution study uncoiled the ability of GAR-NP and iRGD-GAR-NP to accumulate in the colons of dimethyl hydrazine-induced CRC-bearing Sprague-Dawely (SD) rats. In vivo antitumor efficacy study demonstrated the better effect of iRGD-GAR-NP to reduce CRC tumor progression in experimental animals. The survival rate of animals was also increased by 166% in the case of iRGD-GAR-NP compared to CRC-bearing animals received no treatment.

Apigenin-loaded galactose tailored PLGA nanoparticles: A possible strategy for liver targeting to treat hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is the most common hepatic malignancy worldwide. Recent reports focusing on the efficacy of apigenin-loaded nanoparticles (NPs) in combating the progress of HCC encouraged us to develop galactose-tailored PLGA NPs loaded with apigenin (API-GAL-NPs) for active liver targeting to treat HCC. Two kinds of apigenin NPs, such as apigenin-PLGA NPs (API-NPs) and API-GAL-NPs were fabricated and characterized by size, surface morphology, encapsulation efficacy, and in vitro drug release kinetics. In vitro assays were performed on HepG2 cells to check the cellular internalization, cytotoxic potential, and apoptotic potential of free apigenin (API), API-NPs, and API-GAL-NPs. In this stdy, API-GAL-NPs exhibited improved cellular internalization of API resulting in significantly high cytotoxic and apoptotic potentials to HepG2 cells over API and API-NPs. In in vivo studies, API-GAL-NPs exhibited a better protective effect against DEN-induced HCC in rats evidenced by the significant reduction of nodule formation, downregulation of matrix metalloproteinases (MMP-2 and MMP-9), and induction of apoptosis in the liver than API and API-NPs. Histopathological studies and scintigraphic imaging also confirmed that API-GAL-NPs treatment achieved better therapeutic efficacy against DEN-induced HCC in rats over API-NPs. In conclusion, API-GAL-NPs may serve as a potential therapeutic agent against HCC in the future by achieving improved liver targeting.

SPECT Imaging of SST2-Expressing Tumors with 99mTc-Based Somatostatin Receptor Antagonists: The Role of Tetraamine, HYNIC, and Spacers.

[99mTc]Tc-HYNIC-TOC is the most widely used 99mTc-labeled somatostatin receptor (SST) agonist for the SPECT imaging of SST-expressing tumors, such as neuroendocrine tumors. Recently, radiolabeled SST antagonists have shown improved diagnostic efficacy over agonists. 99mTc-labeled SST antagonists are lacking in clinical practice. Surprisingly, when [99mTc]Tc-HYNIC was conjugated to the SST2 antagonist SS01, SST2 imaging was not feasible. This was not the case when [99mTc]Tc-N4 was conjugated to SS01. Here, we assessed the introduction of different spacers (X: ß-Ala, Ahx, Aun and PEG4) among HYNIC and SS01 with the aim of restoring the affinity of HYNIC conjugates. In addition, we used the alternative antagonist JR11 for determining the suitability of HYNIC with 99mTc-labeled SST2 antagonists. We performed a head-to-head comparison of the N4 conjugates of SS01 and JR11. [99mTc]Tc-HYNIC-TOC was used as a reference, and HEK-SST2 cells were used for in vitro and in vivo evaluation. EDDA was used as a co-ligand for all [99mTc]Tc-HYNIC conjugates. The introduction of Ahx restored, to a great extent, the SST2-mediated cellular uptake of the [99mTc]Tc-HYNIC-X conjugates (X: spacer), albeit lower than the corresponding [99mTc]Tc-N4-conjugates. SPECT/CT images showed that all 99mTc-labeled conjugates accumulated in the tumor and kidneys with [99mTc]Tc-HYNIC-PEG4-SS01, [99mTc]Tc-N4-SS01 and [99mTc]Tc-N4-JR11 having notably higher kidney uptake. Biodistribution studies showed similar or better tumor-to-non-tumor ratios for the [99mTc]Tc-HYNIC-Ahx conjugates, compared to the [99mTc]Tc-N4 counterparts. The [99mTc]Tc-HYNIC-Ahx conjugates of SS01 and JR11 were comparable to [99mTc]Tc-HYNIC-TOC as imaging agents. HYNIC is a suitable chelator for the development of 99mTc-labeled SST2 antagonists when a spacer of appropriate length, such as Ahx, is used.

Selection of the First 99mTc-Labelled Somatostatin Receptor Subtype 2 Antagonist for Clinical Translation-Preclinical Assessment of Two Optimized Candidates.

Recently, radiolabelled antagonists targeting somatostatin receptors subtype 2 (SST2) in neuroendocrine neoplasms demonstrated certain superior properties over agonists. Within the ERA-PerMED project "TECANT" two 99mTc-Tetramine (N4)-derivatized SST2 antagonists (TECANT-1 and TECANT-2) were studied for the selection of the best candidate for clinical translation. Receptor-affinity, internalization and dissociation studies were performed in human embryonic kidney-293 (HEK293) cells transfected with the human SST2 (HEK-SST2). Log D, protein binding and stability in human serum were assessed. Biodistribution and SPECT/CT studies were carried out in nude mice bearing HEK-SST2 xenografts, together with dosimetric estimations from mouse-to-man. [99mTc]Tc-TECANT-1 showed higher hydrophilicity and lower protein binding than [99mTc]-TECANT-2, while stability was comparable. Both radiotracers revealed similar binding affinity, while [99mTc]Tc-TECANT-1 had higher cellular uptake (>50%, at 2 h/37 °C) and lower dissociation rate (<30%, at 2 h/37 °C). In vivo, [99mTc]Tc-TECANT-1 showed lower blood values, kidney and muscles uptake, whereas tumour uptake was comparable to [99mTc]Tc-TECANT-2. SPECT/CT imaging confirmed the biodistribution results, providing the best tumour-to-background image contrast for [99mTc]Tc-TECANT-1 at 4 h post-injection (p.i.). The estimated radiation dose amounted to approximately 6 µSv/MBq for both radiotracers. This preclinical study provided the basis of selection of [99mTc]Tc-TECANT-1 for clinical translation of the first 99mTc-based SST2 antagonist.

CD-340 functionalized doxorubicin-loaded nanoparticle induces apoptosis and reduces tumor volume along with drug-related cardiotoxicity in mice.

BACKGROUND AND OBJECTIVE: Targeted drug delivery of nanoparticles decorated with site-specific recognition ligands is of considerable interest to minimize cytotoxicity of chemotherapeutics in the normal cells. The study was designed to develop CD-340 antibody-conjugated polylactic-co-glycolic acid (PLGA) nanoparticles loaded with a highly water-soluble potent anticancer drug, doxorubicin (DOX), to specifically deliver entrapped DOX to breast cancer cells. METHODS: The study showed how to incorporate water-soluble drug in a hydrophobic PLGA (85:15) based matrix which otherwise shows poor drug loading due to leaching effect. The optimized formulation was covalently conjugated to anti-human epidermal growth factor receptor-2 (HER2) antibody (CD-340). Surface conjugation of the ligand was assessed by flow cytometry, confocal microscopy, and gel electrophoresis. Selectivity and cytotoxicity of the experimental nanoparticles were tested on human breast cancer cells SKBR-3, MCF-7, and MDA-MB-231. Both CD-340-conjugated and unconjugated nanoparticles were undergone in vitro and in vivo characterization. RESULT: Higher level of incorporation of DOX (8.5% W/W), which otherwise shows poor drug loading due to leaching effect of the highly water-soluble drug, was seen in this method. In HER2-overexpressing tumor xenograft model, radiolabeled antibody-conjugated nanoparticles showed preferentially more of the formulation accumulation in the tumor area when compared to the treatments with the unconjugated one or with the other control groups of mice. The ligand conjugated nanoparticles showed considerable potential in reduction of tumor growth and cardiac toxicity of DOX in mice, a prominent side-effect of the drug. CONCLUSION: In conclusion, CD-340-conjugated PLGA nanoparticles containing DOX preferentially delivered encapsulated drug to the breast cancer cells and in breast tumor and reduced the breast tumor cells by apoptosis. Site-specific delivery of the formulation to neoplastic cells did not affect normal cells and showed a drastic reduction of DOX-related cardiotoxicity.

Garcinol-loaded novel cationic nanoliposomes: in vitro and in vivo study against B16F10 melanoma tumor model.

Aim: Garcinol (GAR)-loaded cationic nanoliposomes were developed to achieve potential antitumor efficacy on B16F10 melanoma cells in vitro and in vivo. Materials & methods: Two different phospholipids namely, distearoyl phosphatidylcholine (DSPC) and dipalmitoyl phosphatidylcholine (DPPC) were used in formulation to elucidate the difference in cellular uptake, cytotoxicity, in vivo tumor uptake (by scintigraphic imaging after technetium-99m radiolabeling) and therapeutic efficacy. Results: Different in vitro protocols, for example, MTT assay, apoptosis study, gene expression analysis, chromatin condensation and cytoskeleton breakdown analysis in B16F10 cell lines as well as scintigraphic analysis and tumor inhibition studies (B16F10 tumor xenograft model) revealed superiority of GAR-DPPC than GAR-DSPC and free GAR in melanoma prevention. Conclusion: Cationic nanoliposomal formulations could be a future medication for skin cancer treatment.

Peripheral nerve targeting by procaine-conjugated ribavirin-loaded dual drug nanovesicle.

AIM: Procaine that is able to reach the peripheral nervous system (PNS) was conjugated as a ligand with lipid nanovesicle and loaded with ribavirin (a broad spectrum antiviral drug incapable of entering the PNS on its own) to target the PNS with a dual-drug effect. MATERIALS & METHODS: Different physicochemical characterizations, Î³-scintigraphy and electromyography of the developed nanovesicle were conducted. RESULTS: Marked capability of the optimized radiolabeled formulation to target PNS was observed in rats. Electromyography signals were reduced after treatment with the formulation on conscious rats. CONCLUSION: The developed nanocarrier can deliver drug successfully at the PNS and reduce excitation of the nerve and thus give a better therapeutic option for treatment of various diseases and disorders of the PNS.

Development of a peptide-based bifunctional chelator conjugated to a cytotoxic drug for the treatment of melanotic melanoma.

The cytotoxic drug gemcitabine (GEM) has been conjugated to receptor-binding peptides to target melanoma tumors. A hexapeptide having a Lys-Gly-His-Lys sequence (pep-1), an octapeptide with an Arg-Gly-Asp-Lys-Gly-His-Lys sequence (pep-2), a GEM-conjugated Lys-Gly-His-Lys peptide (GEM-pep-3) and a GEM-conjugated Asp-Gly-Arg peptide (GEM-pep-4) were synthesized and characterized. In vitro uptake of fluorescently labeled GEM-pep-3 and GEM-pep-4 on B16F10 cells was investigated. Fluorescence microscopy studies demonstrated significant uptake of GEM-pep-3 in the B16F10 mouse melanoma cell line. The peptides and GEM-coupled peptides were radiolabeled with [99mTc(CO)3(H2O)3]+ and examined for in vitro cell binding in the B16F10 melanoma cell line and in vivo biodistribution and scintigraphic studies in a B16F10 melanoma tumor-bearing mice model. In vitro cellular uptake studies and biological evaluation confirmed significant deposition of GEM-pep-3 at the melanoma tumor site. The MTT assay depicted higher cytotoxic behaviour of GEM-pep-3 than free GEM. A considerable amount of cell apoptosis was also observed in B16F10 cells. Finally, the in vivo therapeutic efficacy study revealed a significant decrease in tumor growth in the GEM-pep-3-treated animal model. These studies reveal enough potentiality of GEM-pep-3 to treat melanoma and underline the need for further evaluation.

Apigenin loaded nanoparticle delayed development of hepatocellular carcinoma in rats.

Hepatocellular carcinoma (HCC) is one of the major causes of cancer related death globally. Apigenin, a dietary flavonoid, possesses anti-tumor activity against HCC cells in-vitro. Development, physicochemical characterization of apigenin loaded nanoparticles (ApNp), biodistribution pattern and pharmacokinetic parameters of apigenin upon intravenous administration of ApNp, and effect of ApNp treatment in rats with HCC were investigated. Apigenin loaded nanoparticles had a sustained drug release pattern and successfully reached the hepatic cancer cells in-vitro as well as in liver of carcinogenic animals. ApNp predominantly delayed the progress of HCC in chemical induced hepatocarcinogenesis in rats. Quantification of apigenin by liquid chromatography-mass spectroscopy (LC-MS/MS) showed that apigenin availability significantly increased in blood and liver upon ApNp treatment. Apigenin loaded nanoparticle delivery substantially controlled the severity of hepatocellular carcinoma and could be a future hope for lingering the survival in hepatic cancer patients.

Chitosan-coated nanoparticles enhanced lung pharmacokinetic profile of voriconazole upon pulmonary delivery in mice.

AIM: Chitosan-coated polylactic-co-glycolic acid nanoparticles of voriconazole (VChNP) were developed to increase residence time and provide sustained drug release locally to treat recurrent lung-fungal infection. MATERIALS & METHODS: VChNP has been developed using a simple, unique technique and characterized. Pharmacokinetics, lung deposition with time and gamma imaging were conducted with optimized formulations. RESULTS: The deposition of fluorescein isothiocyanate-labeled VChNP in lung was confirmed by confocal microscopy. Gamma-scintigraphic images showed that Tc-99m-labeled VChNP had better pulmonary retention for longer period than that of noncoated formulation. Drastic improvement in pharmacokinetic profile of VChNP than noncoated formulation was observed. CONCLUSION: Thus, VChNP may be useful for effective pulmonary delivery with improved bioavailability. Such chitosan-coated nanoparticles may open up a new avenue for efficacious treatment of lung-fungal infection.

Lipid-based nanocarrier efficiently delivers highly water soluble drug across the blood-brain barrier into brain.

Delivering highly water soluble drugs across blood-brain barrier (BBB) is a crucial challenge for the formulation scientists. A successful therapeutic intervention by developing a suitable drug delivery system may revolutionize treatment across BBB. Efforts were given here to unravel the capability of a newly developed fatty acid combination (stearic acid:oleic acid:palmitic acid = 8.08:4.13:1) (ML) as fundamental component of nanocarrier to deliver highly water soluble zidovudine (AZT) as a model drug into brain across BBB. A comparison was made with an experimentally developed standard phospholipid-based nanocarrier containing AZT. Both the formulations had nanosize spherical unilamellar vesicular structure with highly negative zeta potential along with sustained drug release profiles. Gamma scintigraphic images showed both the radiolabeled formulations successfully crossed BBB, but longer retention in brain was observed for ML-based formulation (MGF) as compared to soya lecithin (SL)-based drug carrier (SYF). Plasma and brain pharmacokinetic data showed less clearance, prolonged residence time, more bioavailability and sustained release of AZT from MGF in rats compared to those data of the rats treated with SYF/AZT suspension. Thus, ML may be utilized to successfully develop drug nanocarrier to deliver drug into brain across BBB, in a sustained manner for a prolong period of time and may provide an effective therapeutic strategy for many diseases of brain. Further, many anti-HIV drugs cannot cross BBB sufficiently. Hence, the developed formulation may be a suitable option to carry those drugs into brain for better therapeutic management of HIV.

Garcinol loaded vitamin E TPGS emulsified PLGA nanoparticles: preparation, physicochemical characterization, in vitro and in vivo studies.

Garcinol (GAR) is a naturally occurring polyisoprenylated phenolic compound. It has been recently investigated for its biological activities such as antioxidant, anti-inflammatory, anti ulcer, and antiproliferative effect on a wide range of human cancer cell lines. Though the outcomes are very promising, its extreme insolubility in water remains the main obstacle for its clinical application. Herein we report the formulation of GAR entrapped PLGA nanoparticles by nanoprecipitation method using vitamin E TPGS as an emulsifier. The nanoparticles were characterized for size, surface morphology, surface charge, encapsulation efficiency and in vitro drug release kinetics. The MTT assay depicted a high amount of cytotoxicity of GAR-NPs in B16F10, HepG2 and KB cells. A considerable amount of cell apoptosis was observed in B16f10 and KB cell lines. In vivo cellular uptake of fluorescent NPs on B16F10 cells was also investigated. Finally the GAR loaded NPs were radiolabeled with technetium-99m with >95% labeling efficiency and administered to B16F10 melanoma tumor bearing mice to investigate the in vivo deposition at the tumor site by biodistribution and scintigraphic imaging study. In vitro cellular uptake studies and biological evaluation confirm the efficacy of the formulation for cancer treatment.

Exploring the Potential of (99m)Tc(CO)3-Labeled Triazolyl Peptides for Tumor Diagnosis.

In recent years the authors have reported on (99m)Tc(CO)3-labeled peptides that serve as carriers for biomolecules or radiopharmaceuticals to the tumors. In continuation of that work they report the synthesis of a pentapeptide (Met-Phe-Phe-Gly-His; pep-1), a hexapeptide (Met-Phe-Phe-Asp-Gly-His; pep-2), and a tetrapeptide (Asp-Gly-Arg-His; pep-3) and the attachment of 3-amino-1,2,4-triazole to the ß carboxylic function of the aspartic acid unit of pep-2 and pep-3. The pharmacophores were radiolabeled in high yields with [(99m)Tc(CO)3(H2O)3](+) metal aqua ion, characterized for their stability in serum and saline, as well as in His solution, and found to be substantially stable. B16F10 cell line binding studies showed favorable uptake and internalization. In vivo behavior of the radiolabeled triazolyl peptides was assessed in mice bearing induced tumor. The (99m)Tc(CO)3-triazolyl pep-3 demonstrated rapid urinary clearance and comparatively better tumor uptake. Imaging studies showed visualization of the tumor using (99m)Tc(CO)3-triazolyl pep-3, but due to high abdominal background, low delineation occurred. Based on the results further experiments will be carried out for targeting tumor with triazolyl peptides.

Bio-assay guided isolation of alpha-glucosidase inhibitory constituents from Eclipta alba.

Eclipta alba (L.) Hassk is used traditionally in diabetes mellitus in India and the plant extract is reported to possess anti-diabetic activity. A bioactivity-guided isolation approach based on alpha-glucosidase inhibition was used to identify the constituents contributing towards the inhibition of the enzyme and probably contributing towards its anti-diabetic activity. Four echinocystic acid glycosides were thus isolated, of which eclalbasaponin VI, isolated from the n-butanol fraction, was found to be the most potent (IC50 54.2 +/- 1.3 microM). The compound is an uncompetitive type of inhibitor with Ki 26.1 microM. A quantitative estimation of the constituents was established using RP-HPLC.