Breast Cancer with Increased Drug Resistance, Invasion Ability, and Cancer Stem Cell Properties through Metabolism Reprogramming.

Breast cancer is a heterogeneous disease, and the survival rate of patients with breast cancer strongly depends on their stage and clinicopathological features. Chemoradiation therapy is commonly employed to improve the survivability of patients with advanced breast cancer. However, the treatment process is often accompanied by the development of drug resistance, which eventually leads to treatment failure. Metabolism reprogramming has been recognized as a mechanism of breast cancer resistance. In this study, we established a doxorubicin-resistant MCF-7 (MCF-7-D500) cell line through a series of long-term doxorubicin in vitro treatments. Our data revealed that MCF-7-D500 cells exhibited increased multiple-drug resistance, cancer stemness, and invasiveness compared with parental cells. We analyzed the metabolic profiles of MCF-7 and MCF-7-D500 cells through liquid chromatography−mass spectrometry. We observed significant changes in 25 metabolites, of which, 21 exhibited increased levels (>1.5-fold change and p < 0.05) and 4 exhibited decreased levels (<0.75-fold change and p < 0.05) in MCF-7 cells with doxorubicin resistance. These results suggest the involvement of metabolism reprogramming in the development of drug resistance in breast cancer, especially the activation of glycolysis, the tricarboxylic acid (TCA) cycle, and the hexamine biosynthesis pathway (HBP). Furthermore, most of the enzymes involved in glycolysis, the HBP, and the TCA cycle were upregulated in MCF-7-D500 cells and contributed to the poor prognosis of patients with breast cancer. Our findings provide new insights into the regulation of drug resistance in breast cancer, and these drug resistance-related metabolic pathways can serve as targets for the treatment of chemoresistance in breast cancer.

Intraligand Charge Transfer Enables Visible-Light-Mediated Nickel-Catalyzed Cross-Coupling Reactions.

We demonstrate that several visible-light-mediated carbon-heteroatom cross-coupling reactions can be carried out using a photoactive NiII precatalyst that forms in situ from a nickel salt and a bipyridine ligand decorated with two carbazole groups (Ni(Czbpy)Cl2 ). The activation of this precatalyst towards cross-coupling reactions follows a hitherto undisclosed mechanism that is different from previously reported light-responsive nickel complexes that undergo metal-to-ligand charge transfer. Theoretical and spectroscopic investigations revealed that irradiation of Ni(Czbpy)Cl2 with visible light causes an initial intraligand charge transfer event that triggers productive catalysis. Ligand polymerization affords a porous, recyclable organic polymer for heterogeneous nickel catalysis of cross-coupling reactions. The heterogeneous catalyst shows stable performance in a packed-bed flow reactor during a week of continuous operation.

Heterogeneous metallaphotoredox catalysis in a continuous-flow packed-bed reactor.

Metallaphotoredox catalysis is a powerful and versatile synthetic platform that enables cross-couplings under mild conditions without the need for noble metals. Its growing adoption in drug discovery has translated into an increased interest in sustainable and scalable reaction conditions. Here, we report a continuous-flow approach to metallaphotoredox catalysis using a heterogeneous catalyst that combines the function of a photo- and a nickel catalyst in a single material. The catalyst is embedded in a packed-bed reactor to combine reaction and (catalyst) separation in one step. The use of a packed bed simplifies the translation of optimized batch reaction conditions to continuous flow, as the only components present in the reaction mixture are the substrate and a base. The metallaphotoredox cross-coupling of sulfinates with aryl halides was used as a model system. The catalyst was shown to be stable, with a very low decrease of the yield (≈1% per day) during a continuous experiment over seven days, and to be effective for C-O arylations when carboxylic acids are used as nucleophile instead of sulfinates.

NLIP and HAD-like Domains of Pah1 and Lipin 1 Phosphatidate Phosphatases Are Essential for Their Catalytic Activities.

Saccharomyces cerevisiae Pah1 phosphatidate phosphatase (PAP) catalyzes the dephosphorylation of phosphatidate to yield diacylglycerol, controlling phospholipids and triacylglycerol metabolisms. Pah1 and human Lipin 1 are intrinsically disordered proteins with 56% and 43% unfolded regions, respectively. Truncation analysis of the conserved and non-conserved regions showed that N- and C-conserved regions are essential for the catalytic activity of Pah1. PAP activities can be detected in the conserved N-terminal Lipin (NLIP) domain and C-terminal Lipin (CLIP)/haloacid dehalogenase (HAD)-like domain of Pah1 and Lipin 1, suggesting that the evolutionarily conserved domains are essential for the catalytic activity. The removal of disordered hydrophilic regions drastically reduced the protein solubility of Pah1. Thioredoxin is an efficient fusion protein for production of soluble NLIP-HAD recombinant proteins in Escherichia coli.

Rapid Screening of New Psychoactive Substances Using pDART-QqQ-MS.

Drug abuse is a severe social problem worldwide. Particularly, the issue of new psychoactive substances (NPSs) have increasingly emerged. NPSs are structural or functional analogs of traditional illicit drugs, such as cocaine, cannabis, and amphetamine; these molecules provide the same or more severe neurological effects. Usually, immunoassays are utilized in the preliminary screening method. However, NPSs have poor detectability in commercially available immunoassay kits. Meanwhile, various chromatography combined with the mass spectrometry platform have been developed to quantify NPSs. Still, a significant amount of time and resources are required during these procedures. Therefore, we established a rapid analytical platform for NPSs employing paper-loaded direct analysis in real time triple quadrupole mass spectrometry (pDART-QqQ-MS). We implemented this platform for the semiquantitative analysis of forensic drug tests in urine. This platform significantly shrinks the analytical time of a single sample within 30 s and requires a low volume of the specimen. The platform can detect 21 NPSs in urine mixtures at a lower limit of qualification of concentration ranging from 20 to 75 nanograms per milliliter (ng mL-1) and is lower than the cutoff value of currently available immune-based devices for detecting multiple drugs (1000 ng mL-1). Urine samples from drug addicts have been collected to verify the platform's effectiveness. By combining efficiency and accuracy, our platform offers a promising solution for addressing the challenges posed by NPSs in drug abuse detection.

Sterically polymer-based liposomal complexes with dual-shell structure for enhancing the siRNA delivery.

The sterically polymer-based liposomal complexes (SPLexes) were formed by cationic polymeric liposomes and pH-sensitive diblock copolymer were studied for their capabilities in improving the stability with high efficiency of siRNA delivery. The SPLexes were formed a dual-shelled structure and uniform size distribution. The PEGylated outer shell could mitigate the phagocytosis and reduce the cytotoxicity. Moreover, the folated SPLexes improved 42.9× accumulation in vitro and 1.7× tumor uptake in vivo in contrast with nonfolated SPLexes. The protonated copolymer at low pH would improve the siRNA released into cytoplasm following SPLexes fusion with the endo/lysosome membrane and inhibited the protein expression to 75.6 ± 4.5% efficiently. Results of this study significantly contribute to efforts to develop lipoplexes based siRNA delivery systems.

Rehardening and the Protective Effect of Gamma-Polyglutamic Acid/Nano-Hydroxyapatite Paste on Surface-Etched Enamel.

Many revolutionary approaches are on the way pertaining to the high occurrence of tooth decay, which is an enduring challenge in the field of preventive dentistry. However, an ideal dental care material has yet to be fully developed. With this aim, this research reports a dramatic enhancement in the rehardening potential of surface-etched enamels through a plausible synergistic effect of the novel combination of γ-polyglutamic acid (γ-PGA) and nano-hydroxyapatite (nano-HAp) paste, within the limitations of the study. The percentage of recovery of the surface microhardness (SMHR%) and the surface parameters for 9 wt% γ-PGA/nano-HAp paste on acid-etched enamel were investigated with a Vickers microhardness tester and an atomic force microscope, respectively. This in vitro study demonstrates that γ-PGA/nano-HAp treatment could increase the SMHR% of etched enamel to 39.59 ± 6.69% in 30 min. To test the hypothesis of the rehardening mechanism and the preventive effect of the γ-PGA/nano-HAp paste, the surface parameters of mean peak spacing (Rsm) and mean arithmetic surface roughness (Ra) were both measured and compared to the specimens subjected to demineralization and/or remineralization. After the treatment of γ-PGA/nano-HAp on the etched surface, the reduction in Rsm from 999 ± 120 nm to 700 ± 80 nm suggests the possible mechanism of void-filling within a short treatment time of 10 min. Furthermore, ΔRa-I, the roughness change due to etching before remineralization, was 23.15 ± 3.23 nm, while ΔRa-II, the roughness change after remineralization, was 11.99 ± 3.90 nm. This statistically significant reduction in roughness change (p < 0.05) implies a protective effect against the demineralization process. The as-developed novel γ-PGA/nano-HAp paste possesses a high efficacy towards tooth microhardness rehardening, and a protective effect against acid etching.

Peptides as a material platform for gene delivery: Emerging concepts and converging technologies.

Successful gene therapies rely on methods that safely introduce DNA into target cells and enable subsequent expression of proteins. To that end, peptides are an attractive materials platform for DNA delivery, facilitating condensation into nanoparticles, delivery into cells, and subcellular release to enable protein expression. Peptides are programmable materials that can be designed to address biocompatibility, stability, and subcellular barriers that limit efficiency of non-viral gene delivery systems. This review focuses on fundamental structure-function relationships regarding peptide design and their impact on nanoparticle physical properties, biologic activity, and biocompatibility. Recent peptide technologies utilize multi-dimensional structures, non-natural chemistries, and combinations of peptides with lipids to achieve desired properties and efficient transfection. Advances in DNA cargo design are also presented to highlight further opportunities for peptide-based gene delivery. Modern DNA designs enable prolonged expression compared to traditional plasmids, providing an additional component that can be synergized with peptide carriers for improved transfection. Peptide transfection systems are poised to become a flexible and efficient platform incorporating new chemistries, functionalities, and improved DNA cargos to usher in a new era of gene therapy.

Biotin-Decorated PAMAM G4.5 Dendrimer Nanoparticles to Enhance the Delivery, Anti-Proliferative, and Apoptotic Effects of Chemotherapeutic Drug in Cancer Cells.

Biotin receptors are overexpressed by various types of solid cancer cells and play a significant role in tumor metabolism, growth, and metastasis. Thus, targeting the biotin receptors on tumor cells may enhance the efficiency and reduce the side-effects of chemotherapy. The aim of this study was to develop a biotin-coupled poly(amido)amine (PAMAM) (PG4.5) dendrimer nanoparticle to enhance the tumor-specific delivery and intracellular uptake of anticancer drugs via receptor-mediated endocytosis. We modified PG4.5 with diethylenetriamine (DETA) followed by biotin via an amide bond and characterized the resulting PG4.5-DETA-biotin nanoparticles by 1H NMR, FTIR, and Raman spectroscopy. Loading and releasing of gemcitabine (GEM) from PG4.5-DETA-biotin were evaluated by UV-Visible spectrophotometry. Cell viability and cellular uptake were examined by MTT assay and flow cytometry to assess the biocompatibility, cellular internalization efficiency and antiproliferative activity of PG4.5-DETA-biotin/GEM. Gemcitabine-loaded PG4.5-DETA-biotin nanoparticles were spherical with a particle size of 81.6 ± 6.08 nm and zeta potential of 0.47 ± 1.25 mV. Maximum drug-loading content and encapsulation efficiency were 10.84 ± 0.16% and 47.01 ± 0.71%, respectively. Nearly 60.54 ± 1.99% and 73.96 ± 1.14% of gemcitabine was released from PG4.5-DETA-biotin/GEM nanoparticles after 48 h at the acidic pH values of 6.5 and 5, respectively. Flow cytometry and fluorescence microscopy of cellular uptake results revealed PG4.5-DETA-biotin/GEM nanoparticles selectively targeted cancer cells in vitro. Cytotoxicity assays demonstrated gemcitabine-loaded PG4.5-DETA-biotin significantly reduced cell viability and induced apoptosis in HeLa cells. Thus, biotin-coupled PG4.5-DETA nanocarrier could provide an effective, targeted drug delivery system and selectively convey gemcitabine into tumor cells.

Biodegradable polymer-nanoclay composites as intestinal sleeve implants installed in digestive tract for obesity and type 2 diabetes treatment.

Obesity and type 2 diabetes have become serious health problems in 21st century. Development of non-invasive treatment to treat obesity and type-2 diabetes is still unmet needs. For targeting on this, one of the promising treatments is to implant an intestine sleeve in the gastrointestinal tract for limitation of food absorption. In this context, biodegradable polymer intestine sleeve was composed of polycaprolactone (PCL), poly-DL-lactic acid (PDLLA) and disk-shape nano-clay (Laponite®), and fabricated as an implantable device. Here, Laponite® as a rheological additive to improve the compatibility of PCL and PDLLA, and the polymers/clay composites were also evaluated by scanning electron microscopy SEM analysis and mechanical measurements. The mass ratio 90/10/1 of PCL/PDLLA/Laponite® composite was selected for fabrication of intestine sleeve, because of the highest toughness and flexibility, which are tensile strength of 91.9 N/mm2 and tensile strain of 448% at the failure point. The prepared intestine sleeve was implanted and deployed at the duodenum in type2 diabetic rats, providing significant benefits in control of the body weight and blood glucose, while compared with the non-implanted type 2 diabetic rats. More importantly, the food intake records and histopathological section reports presented that the implanted rats still have normal appetites and no noticeable acute symptoms of inflammation in the end of the test. These appreciable performances suggested the implantation of biocompatible polymer composites has a highly potential treatment for obesity and type 2 diabetes.

In vitro siRNA delivery via diethylenetriamine- and tetraethylenepentamine-modified carboxyl group-terminated Poly(amido)amine generation 4.5 dendrimers.

The recent discovery of small interfering RNAs (siRNAs) has opened new avenues for designing personalized treatment options for various diseases. However, the therapeutic application of siRNAs has been confronted with many challenges because of short half-life in circulation, poor membrane penetration, difficulty in escaping from endosomes, and insufficient release into the cytosol. To overcome these challenges, we designed a diethylenetriamine (DETA)- and tetraethylenepentamine (TEPA)-modified polyamidoamine dendrimer generation 4.5 (PDG4.5), and characterized it using 1H nuclear magnetic resonance (NMR), 13C NMR, correlation spectroscopy (COSY), heteronuclear single-quantum correlation spectroscopy (HSQC), and Fourier transform infrared (FTIR) spectroscopy followed by conjugation with siRNA. The PDG4.5-DETA and PDG4.5-TEPA polyplexes exhibited spherical nanosize, ideal zeta potential, and effective siRNA binding ability, protected the siRNA from nuclease attack, and revealed less cytotoxicity of PDG4.5-DETA and PDG4.5-TEPA in HeLa cells. More importantly, the polyplexes also revealed good cellular internalization and facilitated translocation of the siRNA into the cytosol. Thus, PDG4.5-DETA and PDG4.5-TEPA can act as potential siRNA carriers in future medical and pharmaceutical applications.

Thermosensitive double network of zwitterionic polymers for controlled mechanical strength of hydrogels.

Zwitterionic hydrogels have promising potential as a result of their anti-fouling and biocompatible properties, but they have recently also gained further attention due to their controllable stimuli responses. We successfully synthesized two zwitterionic polymers, poly(2-methacryloyloxyethyl phosphorylcholine) (poly-MPC) and poly(2-(methacryloyloxy)ethyl dimethyl-(3-sulfopropyl)ammonium hydroxide) (poly-DMAPS), which have complementary ionic sequences in their respective zwitterionic side groups and likely form an interpenetrating double network to improve their mechanical strength. The synthesized poly-MPC was blended in a poly-DMAPS matrix (MD gel) and showed high viscosity, while poly-DMAPS was blended in a poly-MPC hydrogel (DM gel) and revealed UCST behavior as the temperature increased. In addition, cross-section images of the MD hydrogel exhibited its compact and uniform structure, while the DM gel was found to exhibit a porous micro-structure with clear boundaries. The results explained the low viscosity of the DM gel, which was also confirmed via 3D Raman mapping. To sum up, the preliminary data demonstrated that binary zwitterionic hydrogels have thermosensitive mechanical properties, promoting further bio-applications in the future, such as in wound healing.

Localized controlled release of bevacizumab and doxorubicin by thermo-sensitive hydrogel for normalization of tumor vasculature and to enhance the efficacy of chemotherapy.

In a malignant tumor, overexpression of pro-angiogenic factors like vascular endothelial growth factor (VEGF) provokes the production of pathologic vascular networks characterized by leaky, chaotically organized, immature, thin-walled, and ill-perfused. As a result, hostile tumor environment would be developed and profoundly hinders anti-cancer drug activities and fuels tumor progression. In this study, we develop a strategy of sequential sustain release of anti-angiogenic drug, Bevacizumab (BVZ), and anti-cancer drug, Doxorubicin (DOX), using poly (d, l-Lactide)- Poly (ethylene glycol) -Poly (d, l-Lactide) (PDLLA-PEG-PDLLA) hydrogel as a local delivery system. The release profiles of the drugs from the hydrogel were investigated in vitro which confirmed that relatively rapid release of BVZ (73.56 ±â€¯1.39%) followed by Dox (61.21 ±â€¯0.62%) at pH 6.5 for prolonged period. The in vitro cytotoxicity test revealed that the copolymer exhibited negligible cytotoxicity up to 2.5 mg ml-1 concentration on HaCaT and HeLa cells. Likeways, the in vitro degradation of the copolymer showed 41.63 ±â€¯2.62% and 73.25 ±â€¯4.36% weight loss within 6 weeks at pH 7.4 and 6.5, respectively. After a single intratumoral injection of the drug-encapsulated hydrogel on Hela xenograft nude, hydrogel co-loaded with BVZ and Dox displayed the highest tumor suppression efficacy for up to 36 days with no noticeable damage on vital organs. Therefore, localized co-delivery of anti-angiogenic drug and anti-cancer drug by hydrogel system may be a promising approach for enhanced chemotherapeutic efficacy in cancer treatment.

Diselenide linkage containing triblock copolymer nanoparticles based on Bi(methoxyl poly(ethylene glycol))-poly(ε-carprolactone): Selective intracellular drug delivery in cancer cells.

Redox-responsive diselenide bond containing triblock copolymer Bi(mPEG-SeSe)-PCL,Bi(mPEG-SeSe)-PCL was developed for specific drug release in cancer cells. Initially, ditosylated polycaprolactone was prepared via the reaction between polycaprolactone diol (PCL-diol) and tosyl chloride (TsCl). Next, Bi(mPEG-SeSe)-PCL was synthesized via the reaction between ditosylated polycaprolactone and sodium diselenide initiated poly (ethylene glycol) methyl ether tosylate. The synthesized amphiphilic triblock copolymer could self-assemble into uniform nanoparticles in aqueous medium and disassemble upon redox stimuli. The Bi(mPEG-SeSe)-PCL nanoparticles showed a DOX loading content of 5.1 wt% and a loading efficiency of 49%. In vitro drug release studies showed that about 62.4% and 56% of DOX was released from the nanoparticles during 72 h at 37 °C in PBS containing 2 mg/mL (6 mM) GSH and 0.1% H2O2, respectively, whereas only about 30% of DOX was released in PBS under the same conditions. The cell viability (MTT assays) results showed that the synthesized material was biocompatible with above 90% cell viability, and that the DOX-loaded Bi(mPEG-SeSe)-PCL nanoparticles had a high antitumor activity against HeLa cells and low antitumor activity against HaCaT cells, following a 24-h incubation period. Three-dimensional (3D) spheroids of HeLa cells were established for the evaluation of localization of the DOX-loaded nanoparticles into spheroids cells and the successfully inhibition of 3D tumor spheroid growth. The results indicated that the synthesized material Bi(mPEG-SeSe)-PCL was biocompatible and it could be a potential candidate for anticancer drug delivery system.

Mixed Lanthanide Oxide Nanoparticles Coated with Alginate-Polydopamine as Multifunctional Nanovehicles for Dual Modality: Targeted Imaging and Chemotherapy.

Integrating anticancer drugs and diagnostic agents in a polymer nanosystem is an emerging and promising strategy for improving cancer treatment. However, the development of multifunctional nanoparticles (NPs) for an "all-in-one" platform characterized by specific targeting, therapeutic efficiency, and imaging feedback remains an unmet clinical need. In this study, pH-responsive mixed-lanthanide-based multifunctional NPs were fabricated based on simple metal-ligand interactions for simultaneous cancer cell imaging and drug delivery. We investigated two new systems of alginate-polydopamine complexed with either terbium/europium or dysprosium/erbium oxide NPs (Tb/Eu@AlgPDA or Dy/Er@AlgPDA NPs). Tb/Eu@AlgPDA NPs were then functionalized with the tumor-targeting ligand folic acid (FA) and loaded with the anticancer drug doxorubicin (DOX) to form FA-Tb/Eu@AlgPDA-DOX NPs. Using such systems, the mussel-inspired property of PDA was introduced to improve tumor targetability and penetration, in addition to active targeting (via FA-folate receptor interactions). Determining the photoluminescence efficiency showed that the Tb/Eu@AlgPDA system was superior to the Dy/Er@AlgPDA system, presenting intense and sharp emission peaks on the fluorescence spectra. In addition, compared to Dy/Er@AlgPDA NPs (82.4%), Tb/Eu@AlgPDA NPs exhibited negligible cytotoxicity with >93.3% HeLa cell viability found in MTT assays at NP concentrations of up to 0.50 mg/mL and high biocompatibility when incubated with zebrafish (Danio rerio) embryos and larvae. The FA-Tb/Eu@AlgPDA-DOX system exhibited a pH-responsive and sustained drug-release pattern. In a spheroid model of HeLa cells, the FA-Tb/Eu@AlgPDA-DOX system showed a better penetration efficiency and spheroid growth-inhibitory effect than free DOX. After incubation with zebrafish embryos, the FA-Tb/Eu@AlgPDA-DOX system also showed improved antitumor efficacies versus the other experimental groups in HeLa tumor cell xenografted zebrafish. Therefore, our results suggested that FA-Tb/Eu@AlgPDA-DOX NPs are promising multifunctional nanocarriers with therapeutic capacity for tumor targeting and penetration.

Non-Anticoagulant Heparin Prodrug Loaded Biodegradable and Injectable Thermoresponsive Hydrogels for Enhanced Anti-Metastasis Therapy.

Metastasis is a pathogenic spread of cancer cells from the primary site to surrounding tissues and distant organs, making it one of the primary challenges for effective cancer treatment and the major cause of cancer mortality. Heparin-based biomaterials exhibit significant inhibition of cancer cell metastasis. In this study, a non-anticoagulate heparin prodrug is developed for metastasis treatment with a localized treatment system using temperature sensitive, injectable, and biodegradable (poly-(ε-caprolactone-co-lactide)-b-poly(ethylene glycol)-b-poly(ε-caprolactone-co-lactide) polymeric hydrogel. The drug molecule (heparin) is conjugated with the polymer via esterification, and its sustained release is ensured by hydrolysis and polymeric biodegradation. An aqueous solution of the polymer could be used as an injectable solution at below 25 °C and it achieves gel formation at 37 °C. The anti-metastasis effect of the hydrogels is investigated both in vitro and in vivo. The results demonstrated that local administration of injectable heparin-loaded hydrogels effectively promote an inhibitory effect on cancer metastasis.

Tricyclohexylphosphine-Catalyzed Cycloaddition of Enynoates with [60]Fullerene and the Application of Cyclopentenofullerenes as n-Type Materials in Organic Photovoltaics.

The tricyclohexylphosphine-catalyzed [3 + 2] cycloaddition of (E)-alkyl 5-substituted phenylpent-4-en-2-ynoates with [60]fullerene was studied. This reaction undergoes an initial 1,3-addition of phosphines toward the α-carbons of enynoates. Subsequent cycloaddition of the generated 1,3-dipoles with [60]fullerene and elimination of tricyclohexylphosphines resulted in cyclopentenofullerenes in 20-43% yields. The isolated cyclopentenofullerenes were observed to serve as n-type materials in organic photovoltaics, providing a maximum average power conversion efficiency of 3.79 ± 0.29% upon embedding with P3HT in the active layer.

Evaluation of 188Re-labeled PEGylated nanoliposome as a radionuclide therapeutic agent in an orthotopic glioma-bearing rat model.

PURPOSE: In this study, the (188)Re-labeled PEGylated nanoliposome ((188)Re-liposome) was prepared and evaluated as a therapeutic agent for glioma. MATERIALS AND METHODS: The reporter cell line, F98(luc) was prepared via Lentivector expression kit system and used to set up the orthotopic glioma-bearing rat model for non-invasive bioluminescent imaging. The maximum tolerated dose applicable in Fischer344 rats was explored via body weight monitoring of the rats after single intravenous injection of (188)Re-liposome with varying dosages before the treatment study. The OLINDA/EXM 1.1 software was utilized for estimating the radiation dosimetry. To assess the therapeutic efficacy, tumor-bearing rats were intravenously administered (188)Re-liposome or normal saline followed by monitoring of the tumor growth and animal survival time. In addition, the histopathological examinations of tumors were conducted on the (188)Re-liposome-treated rats. RESULTS: By using bioluminescent imaging, the well-established reporter cell line (F98(luc)) showed a high relationship between cell number and its bioluminescent intensity (R(2)=0.99) in vitro; furthermore, it could also provide clear tumor imaging for monitoring tumor growth in vivo. The maximum tolerated dose of (188)Re-liposome in Fischer344 rats was estimated to be 333 MBq. According to the dosimetry results, higher equivalent doses were observed in spleen and kidneys while very less were in normal brain, red marrow, and thyroid. For therapeutic efficacy study, the progression of tumor growth in terms of tumor volume and/or tumor weight was significantly slower for the (188)Re-liposome-treated group than the control group (P<0.05). As a result, the lifespan of glioma-bearing rats treated with (188)Re-liposome was prolonged 10.67% compared to the control group. CONCLUSION: The radiotherapeutic evaluation by dosimetry and survival studies have demonstrated that passive targeting (188)Re-liposome via systemic administration can significantly prolong the lifespan of orthotopic glioma-bearing rats while maintaining reasonable systemic radiation safety. Therefore, (188)Re-liposome could be a potential therapeutic agent for glioblastoma multiforme treatment.

Variability of clinical presentations in three cases of parathyroid carcinoma.

Parathyroid carcinoma accounts for 0.5 to 4.0% of cases of primary hyperparathyroidism. The prognosis depends largely on the extent of successful resection at the time of initial operation. Therefore, early diagnosis before surgery is important. We report 3 cases of primary hyperparathyroidism. The first patient, a 20-year-old uremic female, had refractory hypercalcemia after 5 years of hemodialysis treatment. Hypercalcemia persisted despite repeated parathyroidectomy. Pathology revealed diffuse hyperplasia of the parathyroid glands with focal adenomatous changes. Multiple pulmonary metastases were found later. The second patient, a 45-year-old female with history of nephrolithiasis, presented with severe osteoporosis. She underwent repeated parathyroidectomy for local recurrence. Pathology disclosed typical features of parathyroid carcinoma with adjacent lymph node metastasis. The third patient, a 34-year-old male, had recurrent episodes of extremity fracture and hypercalcemia with palpable neck mass. He underwent resection of the parathyroid tumor. Vascular and capsular invasions were noted microscopically. All three patients were relatively young and had extremely high intact parathyroid hormone (iPTH) level (15 to 31 times the upper limit of normal). The first patient died of hypercalcemia and respiratory failure and the other 2 were treated successfully with surgical excision and, in case 2, combined chemotherapy and radiotherapy. The latter 2 patients had no recurrence during 18 months and 14 months of follow-up, respectively. Our experience with these cases suggests that the combination of the following characteristics are highly suggestive of parathyroid carcinoma: young age, palpable neck mass, concomitant renal and skeletal disease, and extremely high iPTH level in patients with PTH-dependent hypercalcemia.

The PEGylated liposomal doxorubicin improves the delivery and therapeutic efficiency of 188Re-Liposome by modulating phagocytosis in C26 murine colon carcinoma tumor model.

Liposome in delivering radionuclide for cancer therapy has been expansively studied; however, liposome itself can be deliberately entrapped and destroyed by the reticuloendothelial system, causing an insufficiency of the drug delivery, which in turn would restrict the effectiveness of the drug. In this study, mice with subcutaneous implantation of C26 murine colon cancer received an experimental treatment regimen in which mice took delivery of PEGylated liposomal doxorubicin (LipoDox) first, after a three-day interval, of Rhenium-188 encapsulated into PEGylated liposome ((188)Re-Liposome) subsequently and by which suppressed the functioning of reticuloendothelial system for the short term. The data showed that based upon the biodistribution assay and the evaluation of the therapeutic efficacy, (188)Re-Liposome was more sufficiently delivered to tumor sites in mice with this treatment regimen than mice without the regimen, and that cancer mortalities in mice with the treatment regimen were much lower than the mortalities in mice without the regimen. Taken together, a new strategy proposed in this study significantly improved both the (188)Re-Liposome delivery and the effectiveness of (188)Re-Liposome, suggesting that the strategy can be an ideal treatment for cancer.