Holographically Activatable Nanoprobe via Glutathione/Albumin-Mediated Exponential Signal Amplification for High-Contrast Tumor Imaging.

Glutathione (GSH)-activatable probes hold great promise for in vivo cancer imaging, but are restricted by their dependence on non-selective intracellular GSH enrichment and uncontrollable background noise. Here, a holographically activatable nanoprobe caging manganese tetraoxide is shown for tumor-selective contrast enhancement in magnetic resonance imaging (MRI) through cooperative GSH/albumin-mediated cascade signal amplification in tumors and rapid elimination in normal tissues. Once targeting tumors, the endocytosed nanoprobe effectively senses the lysosomal microenvironment to undergo instantaneous decomposition into Mn2+ with threshold GSH concentration of ≈ 0.12 mm for brightening MRI signals, thus achieving high contrast tumor imaging and flexible monitoring of GSH-relevant cisplatin resistance during chemotherapy. Upon efficient up-regulation of extracellular GSH in tumor via exogenous injection, the relaxivity-silent interstitial nanoprobe remarkably evolves into Mn2+ that are further captured/retained and re-activated into ultrahigh-relaxivity-capable complex by stromal albumin in the tumor, and simultaneously allows the renal clearance of off-targeted nanoprobe in the form of Mn2+ via lymphatic vessels for suppressing background noise to distinguish tiny liver metastasis. These findings demonstrate the concept of holographic tumor activation via both tumor GSH/albumin-mediated cascade signal amplification and simultaneous background suppression for precise tumor malignancy detection, surveillance, and surgical guidance.

Sterically Bulky Caging of Transferrin for Photoactivatable Intracellular Delivery.

Photoactivatable ligand proteins are potentially useful for light-induced intracellular delivery of therapeutic and diagnostic cargos through receptor-mediated cellular uptake. Here, we report the simple and effective caging of transferrin (Tf), a representative ligand protein with cellular uptake ability, which has been used in the delivery of various cargos. Tf was modified with several biotin molecules through a photocleavable linker, and then the biotinylated Tf (bTf) was conjugated with the biotin-binding protein, streptavidin (SA), to provide steric hindrance to block the interaction with the Tf receptor. Without exposure to light, the cellular uptake of the bTf-SA complex was effectively inhibited. In response to light exposure, the complex was degraded with the release of Tf, leading to cellular uptake of Tf. Similarly, the cellular uptake of Tf-doxorubicin (Dox) conjugates could be suppressed by caging with biotinylation and SA binding, and the intracellular delivery of Dox could be triggered in a light-dependent manner. The intracellularly accumulated Dox decreased the cell viability to 25% because of the cell growth inhibitory effect of Dox. These results provided proof of principle that the caged Tf can be employed as a photoactivatable molecular device for the intracellular delivery of cargos.

Entropy-Driven Quick Loading of Functional Proteins in Nanohydrogels for Highly Efficient Tumor Targeting Therapy.

With the gradual deep understanding of the tumorigenesis and development process, nanodrug are thought to have great prospects for individualized treatment of tumors. To deliver adequate concentration of active ingredients to targeted tissues, proteins are usually used as carriers to avoid clearance by the immune system. Herein, a new strategy is developed for preparation of the protein-functionalized targeting nanodrugs; different kinds of proteins (albumin, horseradish, transferrin, and ricin) can be quickly loaded in polyacrylic acid nanohydrogels (PAA-NGs) without discrimination within 1 min under the strong driving force of entropy; and the loading efficiency can reach 99% with about 50% loading content. Meanwhile, the activity of the released protein can be well retained. After oriented binding of the targeting agent on the surface of the nanocarriers by a unique and facile technique, the protein-loaded nanodrug exhibits excellent tumor cell uptake and targeting effect. The excellent targeting ability from the oriented binding is further proved by comparing with the non-oriented targeting system. With quick loading of the anti-tumor protein of ricin and oriented binding of transferrin protein (Tf), the targeting nanodrug (PAA-BB@Ricin/Tf) shows a remarkable anti-tumor effect. This study proves a new universal delivery and targeting strategy for improving the nanodelivery system, which has great potentials for clinical application.

Transferrin Conjugated pH- and Redox-Responsive Poly(Amidoamine) Dendrimer Conjugate as an Efficient Drug Delivery Carrier for Cancer Therapy.

INTRODUCTION: A multifunctional redox- and pH-responsive polymeric drug delivery system is designed and investigated for targeted anticancer drug delivery to liver cancer. METHODS: The nanocarrier (His-PAMAM-ss-PEG-Tf, HP-ss-PEG-Tf) is constructed based on generation 4 polyamidoamine dendrimer (G4 PAMAM). Optimized amount of histidine (His) residues is grafted on the surface of PAMAM to obtain enhanced pH-sensitivity and proton-buffering capacity. Disulfide bonds (ss) are introduced between PAMAM and PEG to reach accelerated intracellular drug release. Transferrin (Tf) was applied to achieve active tumor targeting. Doxorubicin (DOX) is loaded in the hydrophobic cavity of the nanocarrier to exert its anti-tumor effect. RESULTS: The results obtained from in vitro and in vivo evaluation indicate that HP-ss-PEG-Tf/DOX complex has pH and redox dual-sensitive properties, and exhibit higher cellular uptake and cytotoxicity than the other control groups. Flow cytometry and confocal microscopy display internalization of HP-ss-PEG-Tf/DOX via clathrin mediated endocytosis and effective endosomal escape in HepG2 cancer cells. Additionally, cyanine 7 labeled HP-ss-PEG-Tf conjugate could quickly accumulate in the HepG2 tumor. Remarkably, HP-ss-PEG-Tf/DOX present superior anticancer activity, enhanced apoptotic activity and lower heart and kidney toxicity in vivo. DISCUSSION: Thus, HP-ss-PEG-Tf is proved to be a promising candidate for effective targeting delivery of DOX into the tumor.

Reversal of multidrug resistance in leukemia cells using a transferrin-modified nanomicelle encapsulating both doxorubicin and psoralen.

To ameliorate multidrug resistance (MDR) observed in leukemia cells, nanomicelles modified by transferrin (Tf-M-DOX/PSO), coencapsulating doxorubicin (DOX) and psoralen (PSO), were designed, synthesized and tested in K562 and doxorubicin-resistant K562 (K562/DOX) cells. In vitro drug release kinetics for constructed nanomicelles were measured using high-performance liquid chromatography. Characterization of the produced nanomicelles was completed using transmission electron microscopy and dynamic light scattering. Uptake of the nanomicelles in K562 cells was investigated using both confocal microscopy and flow cytometry. Apoptosis levels as well as the expression of glycoprotein (P-gp) were analyzing by western blotting and flow cytometry. Cellular cytotoxicity resulting from the exposure of nanomicelles was evaluated using MTT assays. The nanomicelles all showed mild release of DOX in PBS solution. In K562/DOX cells, Tf-M-Dox/PSO exhibited higher uptake compared to the other nanomicelles observed. Furthermore, cellular cytotoxicity when exposed to Tf-M-Dox/PSO was 2.8 and 1.6-fold greater than observed in the unmodified DOX and Tf-nanomicelles loaded with DOX alone, respectively. Tf-M-Dox/PSO strongly increased apoptosis of K562/DOX cells. Finally, the reversal of the drug resistance when cells are exposed to Tf-M-DOX/PSO was associated with P-gp expression inhibition. The Tf-M-Dox/PSO nanomicelle showed a reversal of MDR, with enhanced cellular uptake and delivery release.

Four-wave-mixing microscopy reveals non-colocalisation between gold nanoparticles and fluorophore conjugates inside cells.

Gold nanoparticles have been researched for many biomedical applications in diagnostics, theranostics, and as drug delivery systems. When conjugated to fluorophores, their interaction with biological cells can be studied in situ and real time using fluorescence microscopy. However, an important question that has remained elusive to answer is whether the fluorophore is a faithful reporter of the nanoparticle location. Here, our recently developed four-wave-mixing optical microscopy is applied to image individual gold nanoparticles and in turn investigate their co-localisation with fluorophores inside cells. Nanoparticles from 10 nm to 40 nm diameter were conjugated to fluorescently-labeled transferrin, for internalisation via clathrin-mediated endocytosis, or to non-targeting fluorescently-labelled antibodies. Human (HeLa) and murine (3T3-L1) cells were imaged at different time points after incubation with these conjugates. Our technique identified that, in most cases, fluorescence originated from unbound fluorophores rather than from fluorophores attached to nanoparticles. Fluorescence detection was also severely limited by photobleaching, quenching and autofluorescence background. Notably, correlative extinction/fluorescence microscopy of individual particles on a glass surface indicated that commercial constructs contain large amounts of unbound fluorophores. These findings highlight the potential problems of data interpretation when reliance is solely placed on the detection of fluorescence within the cell, and are of significant importance in the context of correlative light electron microscopy.

A Brief Overview of the Oral Delivery of Insulin as an Alternative to the Parenteral Delivery.

Diabetes mellitus greatly affects the quality of life of patients and has a worldwide prevalence. Insulin is the most commonly used drug to treat diabetic patients and is usually administered through the subcutaneous route. However, this route of administration is ineffective due to the low concentration of insulin at the site of action. This route of administration causes discomfort to the patient and increases the risk of infection due to skin barrier disturbance caused by the needle. The oral administration of insulin has been proposed to surpass the disadvantages of subcutaneous administration. In this review, we give an overview of the strategies to deliver insulin by the oral route, from insulin conjugation to encapsulation into nanoparticles. These strategies are still under development to attain efficacy and effectiveness that are expected to be achieved in the near future.

Biodistribution of TAT or QLPVM coupled to receptor targeted liposomes for delivery of anticancer therapeutics to brain in vitro and in vivo.

Combination therapy has emerged as an efficient way to deliver chemotherapeutics for treatment of glioblastoma. It provides collaborative approach of targeting cancer cells by acting via multiple mechanisms, thereby reducing drug resistance. However, the presence of impermeable blood brain barrier (BBB) restricts the delivery of chemotherapeutic drugs into the brain. To overcome this limitation, we designed a dual functionalized liposomes by modifying their surface with transferrin (Tf) and a cell penetrating peptide (CPP) for receptor and adsorptive mediated transcytosis, respectively. In this study, we used two different CPPs (based on physicochemical properties) and investigated the influence of insertion of CPP to Tf-liposomes on biocompatibility, cellular uptake, and transport across the BBB both in vitro and in vivo. The biodistribution profile of Tf-CPP liposomes showed more than 10 and 2.7 fold increase in doxorubicin and erlotinib accumulation in mice brain, respectively as compared to free drugs with no signs of toxicity.

Systematic Evaluation of Transferrin-Modified Porous Silicon Nanoparticles for Targeted Delivery of Doxorubicin to Glioblastoma.

There is a dire need to develop more effective therapeutics to combat brain cancer such as glioblastoma multiforme (GBM). An ideal treatment is expected to target deliver chemotherapeutics to glioma cells across the blood-brain barrier (BBB). The overexpression of transferrin (Tf) receptor (TfR) on the BBB and the GBM cell surfaces but not on the surrounding cells renders TfR a promising target. While porous silicon nanoparticles (pSiNPs) have been intensely studied as a delivery vehicle due to their high biocompatibility, degradability, and drug-loading capacity, the potential to target deliver drugs with transferrin (Tf)-functionalized pSiNPs remains unaddressed. Here, we developed and systematically evaluated Tf-functionalized pSiNPs (Tf@pSiNPs) as a glioma-targeted drug delivery system. These nanoparticles showed excellent colloidal stability and had a low toxicity profile. As compared with nontargeted pSiNPs, Tf@pSiNPs were selective to BBB-forming cells and GBM cells and were efficiently internalized through clathrin receptor-mediated endocytosis. The anticancer drug doxorubicin (Dox) was effectively loaded (8.8 wt %) and released from Tf@pSiNPs in a pH-responsive manner over 24 h. Furthermore, the results demonstrate that Dox delivered by Tf@pSiNPs induced significantly enhanced cytotoxicity to GBM cells across an in vitro BBB monolayer compared with free Dox. Overall, Tf@pSiNPs offer a potential toolbox for enabling targeted therapy to treat GBM.

Dual functionalized liposomes for efficient co-delivery of anti-cancer chemotherapeutics for the treatment of glioblastoma.

Glioblastoma is a hostile brain tumor associated with high infiltration leading to poor prognosis. Anti-cancer chemotherapeutic agents have limited access into the brain due to the presence of the blood brain barrier (BBB). In this study, we designed a dual functionalized liposomal delivery system, surface modified with transferrin (Tf) for receptor mediated transcytosis and a cell penetrating peptide-penetratin (Pen) for enhanced cell penetration. We loaded doxorubicin and erlotinib into liposomes to enhance their translocation across the BBB to glioblastoma tumor. In vitro cytotoxicity and hemocompatibility studies demonstrated excellent biocompatibility for in vivo administration. Co-delivery of doxorubicin and erlotinib loaded Tf-Pen liposomes revealed significantly (p < 0.05) higher translocation (~15%) across the co-culture endothelial barrier resulting in regression of tumor in the in vitro brain tumor model. The biodistribution of Tf-Pen liposomes demonstrated ~12 and 3.3 fold increase in doxorubicin and erlotinib accumulation in mice brain, respectively compared to free drugs. In addition, Tf-Pen liposomes showed excellent antitumor efficacy by regressing ~90% of tumor in mice brain with significant increase in the median survival time (36 days) along with no toxicity. Thus, we believe that this study would have high impact for treating patients with glioblastoma.

Transferrin/aptamer conjugated mesoporous ruthenium nanosystem for redox-controlled and targeted chemo-photodynamic therapy of glioma.

The blood-brain barrier (BBB) and low targeting are major obstacles for the treatment of gliomas. Accordingly, overcoming the BBB and enhancing the targeting of drugs to the glioma area are key to achieving a good therapeutic effect. Here, we have developed the mesoporous ruthenium nanosystem RBT@MRN-SS-Tf/Apt with dual targeting function. Transferrin (Tf) and aptamer AS1411 (Apt) are grafted on the surfaces of mesoporous ruthenium nanoparticles (MRN) with high loading capacity. This is achieved via redox-cleavable disulfide bonds, serving as both a capping agent and a targeting ligand, enabling the effective penetration of the blood-brain barrier and targeting the glioma. In addition, RBT@MRN-SS-Tf/Apt can specifically kill glioma cells in vitro and in vivo. Moreover, anti-tumor drugs [Ru(bpy)2(tip)]2+ (RBT) will produce reactive oxygen species and induce apoptosis of tumor cells under laser irradiation, providing photodynamic therapy (PDT) for the treatment of gliomas, and further prolonging the median survival period. The study shows that this chemical photodynamic therapy nanosystem can be used as an efficient and powerful synergistic system for the treatment of brain tumors and other brain diseases of the central nervous system. STATEMENT OF SIGNIFICANCE: In order to overcome the blood-brain barrier and low targeting, and enhance the anti-glioma activities of nanodrugs. We have developed RBT@MRN-SS-Tf/Apt with dual targeting function. It is achieved release drug via redox-cleavable disulfide bonds, and enable the effective penetration of the blood-brain barrier and targeting the glioma. Moreover, anti-tumor drugs RBT will produce reactive oxygen species and induce apoptosis of tumor cells under laser irradiation, providing photodynamic therapy (PDT) for the treatment of gliomas, and further prolonging the median survival period. Therefore, this chemical photodynamic therapy nanosystem can be used as an efficient and powerful synergistic system for the treatment of brain tumors and other brain diseases of the central nervous system.

Biodistribution, activation, and retention of proinsulin-transferrin fusion protein in the liver: Mechanism of liver-targeting as an insulin prodrug.

A recombinant proinsulin-transferrin fusion protein (ProINS-Tf) has been previously reported to be a novel long-lasting INS analog, acting specifically on the inhibition of hepatic glucose output. In this study, we investigated the biodistribution, activation and tissue retention of ProINS-Tf to elucidate its liver targeted anti-diabetic mechanism. The biodistribution study revealed that ProINS-Tf exhibited liver specific accumulation after a single intravenous injection, whereas transferrin (Tf) or insulin (INS) showed relatively even distribution among different organs. The conversion of inactive ProINS-Tf into an active immune-reactive INS-Tf form (irINS-Tf) via a Tf receptor (TfR) mediated process only occurred in the liver, but not in other organs. In addition, ProINS-Tf demonstrated a prolonged retention in the liver after an intravenous injection, suggesting the enhanced association of the bifunctional active form, irINS-Tf, within liver cells. Taken together, our results indicate that ProINS-Tf is a highly liver-targeted INS prodrug with a combination of 3 specific actions in liver cells: (1) TfR-mediated binding and uptake of the prodrug on the cell surface, (2) liver-specific, TfR-mediated conversion of the prodrug into its active form, and (3) the bifunctional binding of the active fusion protein to both Tf and INS receptors in the liver to achieve prolonged retention and thus enhanced anti-diabetic activities.

Decreasing TfR1 expression reverses anemia and hepcidin suppression in ß-thalassemic mice.

Iron availability for erythropoiesis and its dysregulation in ß-thalassemia are incompletely understood. We previously demonstrated that exogenous apotransferrin leads to more effective erythropoiesis, decreasing erythroferrone (ERFE) and derepressing hepcidin in ß-thalassemic mice. Transferrin-bound iron binding to transferrin receptor 1 (TfR1) is essential for cellular iron delivery during erythropoiesis. We hypothesize that apotransferrin's effect is mediated via decreased TfR1 expression and evaluate TfR1 expression in ß-thalassemic mice in vivo and in vitro with and without added apotransferrin. Our findings demonstrate that ß-thalassemic erythroid precursors overexpress TfR1, an effect that can be reversed by the administration of exogenous apotransferrin. In vitro experiments demonstrate that apotransferrin inhibits TfR1 expression independent of erythropoietin- and iron-related signaling, decreases TfR1 partitioning to reticulocytes during enucleation, and enhances enucleation of defective ß-thalassemic erythroid precursors. These findings strongly suggest that overexpressed TfR1 may play a regulatory role contributing to iron overload and anemia in ß-thalassemic mice. To evaluate further, we crossed TfR1+/- mice, themselves exhibiting iron-restricted erythropoiesis with increased hepcidin, with ß-thalassemic mice. Resultant double-heterozygote mice demonstrate long-term improvement in ineffective erythropoiesis, hepcidin derepression, and increased erythroid enucleation in relation to ß-thalassemic mice. Our data demonstrate for the first time that TfR1+/- haploinsufficiency reverses iron overload specifically in ß-thalassemic erythroid precursors. Taken together, decreasing TfR1 expression during ß-thalassemic erythropoiesis, either directly via induced haploinsufficiency or via exogenous apotransferrin, decreases ineffective erythropoiesis and provides an endogenous mechanism to upregulate hepcidin, leading to sustained iron-restricted erythropoiesis and preventing systemic iron overload in ß-thalassemic mice.

Delivery of fluorescent-labeled cyclodextrin by liposomes: role of transferrin modification and phosphatidylcholine composition.

Drug-in-CD-in-liposome (DCL) systems which encapsulate the drug/CD inclusion complexes into inner aqueous phase of liposomes have been applied as a novel strategy to improve efficacy of lipophilic antitumor drugs. The aim of this work was to assess the role of transferrin (Tf) modification and phosphatidylcholine (PC) composition on the properties of liposomes containing hydroxypropyl-ß-cyclodextrin (HP-ß-CD). Fluorescence dye, FITC, was conjugated with HP-ß-CD to facilitate the analysis. The resulting FITC-HP-ß-CD was further encapsulated into liposomes and then the liposomes were modified with Tf. The FITC-HP-ß-CD-loaded liposomes with different PC compositions were compared in terms of particle size, zeta potential, FITC content, FITC-HP-ß-CD leakage, phase transition temperature (Tm) and cellular uptake. The apparent partition coefficient values of different PCs were also determined. Compared to PEGylated liposomes, FITC-HP-ß-CD-loaded liposomes modified with Tf had been proved to significantly increase vesicle stability and specific cellular uptake. Moreover, PC composition affected the properties of liposomes. Soybean phosphatidylcholine (SPC) liposomes modified with Tf were found to be more easily internalized into tumor cells than 1,2-dipalmitoyl-sn-glycero-3-phosphatidylcholine (DPPC) and hydrogenated soybean phosphatidylcholine (HSPC) while Tf density on the liposomal surface was similar. And the lipophilicity of SPC was found to be much higher than DPPC and HSPC. Collectively, by the optimization of PC composition, the development of DCL modified with Tf might represent a potential strategy for the antitumor application of lipophilic drugs.

The effects of the glycation of transferrin on chromium binding and the transport and distribution of chromium in vivo.

Chromium (III) has been shown to act as a pharmacological agent improving insulin sensitivity in rodent models of obesity, insulin resistance, and diabetes. To act in beneficial fashion, chromium must reach insulin-sensitive tissues. Chromium is transported from the bloodstream to the tissues by the iron-transport protein transferrin. When blood concentrations of glucose are high (as in a diabetic subject), transferrin can be glycated, modifying its ability to bind and transport iron. However, the effects of glycation of transferrin on its ability to bind and transport Cr have not been examined previously. Storage of transferrin at 37°C in the presence and absence of glucose has significant effects on the binding of Cr. Transferrin stored in the absence of glucose only binds one equivalent of Cr tightly, compared to the normal binding of two equivalents of Cr by transferrin. Glycated transferrin (stored in the presence of glucose) binds two equivalents of Cr but the changes in its extinction coefficient at 245nm that accompany binding suggest that the Cr-bound transferrin possesses a conformation that deviates appreciably from untreated transferrin. These changes have dramatic effects, greatly reducing the ability of transferrin to transport Cr in vivo in rats. The results suggest that glycation of transferrin in subjects with high blood glucose concentrations should reduce the ability of Cr from pharmacological agents to enter tissues.

Transferrin-Targeted Nanoparticles Containing Zoledronic Acid as a Potential Tool to Inhibit Glioblastoma Growth.

The treatment of glioblastoma (GBM) is a challenge for the biomedical research since cures remain elusive. Its current therapy, consisted on surgery, radiotherapy, and concomitant chemotherapy with temozolomide (TMZ), is often uneffective. Here, we proposed the use of zoledronic acid (ZOL) as a potential agent for the treatment of GBM. Our group previously developed self-assembling nanoparticles, also named PLCaPZ NPs, to use ZOL in the treatment of prostate cancer. Here, we updated the previously developed nanoparticles (NPs) by designing transferrin (Tf)-targeted self-assembling NPs, also named Tf-PLCaPZ NPs, to use ZOL in the treatment of brain tumors, e.g., GBM. The efficacy of Tf-PLCaPZ NPs was evaluated in different GBM cell lines and in an animal model of GBM, in comparison with PLCaPZ NPs and free ZOL. Tf-PLCaPZ NPs were characterized by a narrow size distribution and a high incorporation efficiency of ZOL. Moreover, the presence of Tf significantly reduced the hemolytic activity of the formulation. In vitro, in LN229 cells, a significant uptake and cell growth inhibition after treatment with Tf-PLCaPZ NPs was achieved. Moreover, the sequential therapy of TMZ and Tf-PLCaPZ NPs lead to a superior therapeutic activity compared to their single administration. The results obtained in mice xenografted with U373MG, revealed a significant anticancer activity of Tf-PLCaPZ NPs, while the tumors remained unaffected with free TMZ. These promising results introduce a novel type of easy-to-obtain NPs for the delivery of ZOL in the treatment of GBM tumors.

Photolytic Protein Aggregates: Versatile Materials for Controlled Release of Active Proteins.

Photolytic protein aggregates are developed as a facile and versatile platform for light-induced release of active proteins. The proteins modified with biotin through a photo-cleavable linker rapidly form aggregates with streptavidin and biotinylated functional molecules simply by mixing. Light irradiation releases active proteins from the aggregates in high yields, and light-induced uptake of drug-modified transferrin into living cells is successfully demonstrated.

Transferrin conjugates of triazacyclononane-based bifunctional NE3TA chelates for PET imaging: Synthesis, Cu-64 radiolabeling, and in vitro and in vivo evaluation.

Three different polyaminocarboxylate-based bifunctional NE3TA (7-[2-[carboxymethyl)amino]ethyl]-1,4,7-triazacyclononane-1,4-diacetic acid) chelating agents were synthesized for potential use in copper 64-PET imaging applications. The bifunctional chelates were comparatively evaluated using transferrin (Tf) as a model targeting vector that binds to the transferrin receptor overexpressed in many different cancer cells. The transferrin conjugates of the NE3TA-based bifunctional chelates were evaluated for radiolabeling with (64)Cu. In vitro stability and cellular uptake of (64)Cu-radiolabeled conjugates were evaluated in human serum and prostate (PC-3) cancer cells, respectively. Among the three NE3TA-Tf conjugates tested, N-NE3TA-Tf was identified as the best conjugate for radiolabeling with (64)Cu. N-NE3TA-Tf rapidly bound to (64)Cu (>98% radiolabeling efficiency, 1min, RT), and (64)Cu-N-NE3TA-Tf remained stable in human serum for 2days and demonstrated high uptake in PC-3 cancer cells. (64)Cu-N-NE3TA-Tf was shown to have rapid blood clearance and increasing tumor uptake in PC-3 tumor bearing mice over a 24h period. This bifunctional chelate presents highly efficient chelation chemistry with (64)Cu under mild condition that can be applied for radiolabeling of various tumor-specific biomolecules with (64)Cu for potential use in PET imaging applications.

Surface-modified Epirubicin-HCl liposomes and its in vitro assessment in breast cancer cell-line: MCF-7.

BACKGROUND: Epirubicin-HCl is highly efficient for breast cancer management at a concentration of 60-90 mg/m(2). However, its application is limited due to cumulative dose-dependent cardio-toxicity. PURPOSE: The main aim of this study was to formulate breast cancer-targeted liposomal carrier by surface conjugation of transferrin to minimize cardio-toxicity of drug along with improved pharmacokinetic profile. METHOD: Liposomes were formulated by ethanol injection method using HSPC, cholesterol and DSPG and later loaded with drug by the ammonium sulfate gradient method. The formulation was characterized for physicochemical properties like size, zeta potential, entrapment efficiency, TEM; in vitro tests like electro-flocculation, hemolysis and drug release; cell line study (MCF-7 cells); in vivo studies including LD50 determination, pharmacokinetic analysis, myocardial toxicity determination and stability. RESULTS AND DISCUSSION: Optimized formulation had molar ratio of 60:30:8:2 (HSPC:Chol:DSPG:mPEG-DSPE) with entrapment efficiency ∼83%, particle size below 200 nm and zeta potential about -20 mV. In vitro studies proved non-interfering property and drug release character of formulation while cell line studies demonstrated improvement in cell uptake and thereby increased cytotoxicity of targeted formulation. The IC50 value obtained for epirubicin solution, non-targeted and targeted liposomes was 0.675, 0.532 and 0.192 µg/ml, respectively. Furthermore, in vivo tests validated safety and distribution profile of prepared formulations. CONCLUSION: Apt properties of prepared Epirubicin-HCl liposomal formulation warrant its clinical application in breast cancer treatment after further studies.

Facile preparation of hyaluronic acid and transferrin co-modified Fe3O4 nanoparticles with inherent biocompatibility for dual-targeting magnetic resonance imaging of tumors in vivo.

Clinical diagnosis of malignant tumors using nanoprobes needs severe improvements in the aspects of sensitivity and biocompatibility. Integrating a dual-targeting strategy with the selection of human-inherent elements and molecules as raw materials shows great potential in the development of a biosafe and sensitive nanoplatform. To carry out the proposed design, we constructed a biocompatible, dual-targeting MR imaging nanoprobe, based on Fe3O4 nanoparticles (NPs) co-modified with inherently innoxious hyaluronic acid (HA) and transferrin (Tf). HA was used as both a template and a targeting molecule to form Fe3O4@HA NPs through a one-step co-precipitation method, which were then further modified with Tf to obtain the dual-targeting Fe3O4@HA@Tf NPs at room temperature. The excellent biocompatibility of the nanoprobe was demonstrated via toxicity assays in vitro and in vivo. The desirable dual-targeting ability towards tumor cells was confirmed by a cellular uptake test (Hela cells, overexpressing both CD44 and transferrin receptors), and the developed nanoprobe was successfully applied in tumor-targeted MR imaging in vivo. In summation, we developed a dual-targeting Fe3O4 nanoprobe, following a facile procedure at room temperature. The nanoprobe showed a high targeting ability towards tumor cells and excellent biocompatibility, which showed its great potential to be applied in the clinical diagnosis of tumors.