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Inducing mitochondrial malfunction is an appealing strategy to overcome tumor multidrug resistance (MDR). Reported here a versatile mitochondrial-damaging molecule, vitamin E succinate (VES), is creatively utilized to assist MDR reversal of doxorubicin hydrochloride (DOX·HCl) via a nanovesicle platform self-assembled from amphiphilic polyphosphazenes containing pH-sensitive 1H-benzo-[d]imidazol-2-yl) methanamine (BIMA) groups. Driven by multiple non-covalent interactions, VES is fully introduced into the hydrophobic membrane of DOX·HCl-loaded nanovesicles with loading content of 23.5%. The incorporated VES also offers robust anti-leakage property toward DOX·HCl under normal physiological conditions. More importantly, upon release within acidic tumor cells, VES can target mitochondria and result in various dysfunctions including excessive generation of reactive oxygen species (ROS), mitochondrial membrane potential (ΔΨm) loss, and inhibited adenosine triphosphate (ATP) synthesis, which contribute to cell apoptosis and insufficient energy supply for drug efflux pumps. Consequently, the killing-effect of DOX·HCl is significantly enhanced toward drug resistant cancer cells at the optimal mass ratio of DOX·HCl to VES. Further in vivo antitumor investigation on nude mice bearing xenograft drug-resistant human chronic myelogenous leukemia K562/ADR tumors verifies the extremely enhanced anti-tumor efficacy of the dual drug-loaded nanovesicle with the tumor inhibition rate (TIR) of 82.38%. Collectively, this study provides a s safe, facile and promising strategy for both precise drug delivery and MDR eradication to improve cancer therapy.

L-arginine (L-Arg) is an important nitric oxide (NO) donor, and its exploration in NO gas therapy has received widespread attention. Application of nano-platforms that can efficiently deliver L-Arg and induce its rapid conversion to NO becomes a predominant strategy to achieve promising therapeutic effects in tumor treatment. Herein, an enhanced nano-vesicular system of ternary synergistic treatment combining NO therapy, photodynamic therapy (PDT) along with mild photothermal therapy (MPTT) was developed for cancer therapy. We integrated photosensitizer PEGylated indocyanine green (mPEG-ICG) into polyphosphazene PEP nano-vesicles through co-assembly and simultaneously encapsulated NO donor L-Arg into the vesicle center chambers to form mPEG-ICG/L-Arg co-loaded system IA-PEP. The unique nanostructure of vesicle provided considerable loading capacity for mPEG-ICG and L-Arg with 15.9% and 17.95% loading content, respectively, and efficiently prevented mPEG-ICG and L-Arg from leaking. Significantly, the reactive oxygen species (ROS) was produced by IA-PEP under 808 nm laser irradiation to perform PDT against tumors, which concurrently reacted with L-Arg to release NO and arouse gas therapy effectively. Moreover, the mild heat produced by IA-PEP could exhibit cooperative anti-tumor effect with minimal damage. As a consequence, in vivo antitumor investigation on nude mice bearing xenograft MCF-7 tumors verified the potent anti-tumor efficacy of IA-PEP under 808 nm laser irradiation with complete tumor elimination. Taken together, the IA-PEP nano-vesicle system designed in this work may provide a promising treatment paradigm for synergistic cancer treatment. STATEMENT OF SIGNIFICANCE: Nitric oxide (NO) gas therapy has drawn widespread attention due to its "green" treatment paradigm with negligible side effects. L-arginine (L-Arg) is an important NO donor. However, how to efficiently deliver L-Arg and induce NO generation remains a big challenge since L-Arg is a water-soluble small molecule. Herein, we developed a nano-vesicle system IA-PEP to integrate photosensitizer PEGylated indocyanine green and L-Arg with high loading content and to produce a ternary synergistic treatment combining NO therapy, photodynamic therapy (PDT) along with mild-temperature photothermal therapy (MPTT) under 808 nm laser irradiation. The in vivo investigation on nude mice bearing xenograft MCF-7 tumors verified its potent anti-tumor efficacy with complete tumor elimination.

Vitamin E succinate (VES), a succinic acid ester of vitamin E, is one of the most effective anticancer compounds of the vitamin E family. VES can inhibit tumor growth by multiple pathways mainly involve tumor proliferation inhibition, apoptosis induction, and metastasis prevention. More importantly, the mitochondrial targeting and damaging property of VES endows it with great potential in exhibiting synergetic effect with conventional chemotherapeutic drugs and overcoming multidrug resistance (MDR). Given the lipophilicity of VES that hinders its bioavailability and therapeutic activity, nanotechnology with multiple advantages has been widely explored to deliver VES and opened up new avenues for its in vivo application. This review aims to introduce the anticancer mechanisms of VES and summarize its delivery strategies using nano-drug delivery systems. Specifically, VES-based combination therapy for synergetic anticancer effect, MDR-reversal, and oral chemotherapy improvement are highlighted. Finally, the challenges and perspectives are discussed.

Background Epilepsy is one of the most common neurological problems among children. The aim of this survey was to assess the knowledge and attitude among preschool staff in Shanghai regarding epilepsy. Methods A cross-sectional survey was carried out among the staff at selected preschools. A stratified random sampling method was first used to identify suitable subjects. Data were obtained using a self-completed questionnaire. A standardized collection of demographic information was performed, and participants were given a questionnaire about their knowledge and attitudes regarding epilepsy. Results A total of 1069 subjects completed the questionnaire. In this survey, 387 (36.2%) staff members had previously participated in related training. 17.6% of teachers knew how to provide appropriate first aid for seizures. Correct responses regarding first aid for seizures, such as laying the person on his or her side (24.9%), moving harmful objects out of the way (20.7%), protecting the head (36.1%), waiting until the seizure ends (7.9%), and dialing the emergency number (40.1%), were low. The staff members had different attitudes towards children with epilepsy: some subjects had a positive attitude, some had a negative attitude. Conclusions The level of first-aid knowledge among preschool staff in Shanghai relevant to epilepsy was low. There is an urgent need to educate staff about epilepsy and appropriate first-aid practices for seizures.

On the basis of immuno-modulating effect and upregulating the activity of thymidine phosphorylase (TP), interferon-γ (IFN-γ) as a cooperative attacker was explored to enhance the anticancer activity of 5-FU. We designed and prepared a self-assembled nano-vesicular system IFN-γ-EDP formulated by amphiphilic poly((polyethylene glycol)(dodecylphospho-ethanolamine)phosphazene) (EDP) to entrap IFN-γ in the hydrophilic cavity. The IFN-γ-EDP vesicles allowed IFN-γ to accumulate at the tumor site and be taken up by tumor cells, resulting in significantly upregulated expression level of TP, distinct inhibition of cell growth, more cellular apoptosis and more serious cell cycle arrest when administrated combined with 5-FU. Moreover, IFN-γ-EDP could normalize the tumor microenvironment by enhancing the CD4+ and CD8+ T cell populations, promoting the IL-12 secretion and suppressing the IL-10 secretion in tumor. As a consequence, the combination therapy of IFN-γ-EDP with 5-FU achieved remarkably enhanced tumor inhibition rate of 56.9% against CT26 colorectal cancer.

Carboplatin is one of the few platinum-based antitumor drugs used worldwide. Unfortunately, systemic carboplatin therapy is limited by its dose-related myelosuppression. In this study, a viable way to reduce the serious myelotoxicity of carboplatin while improving its therapeutic efficacy using amino-functionalized polyphosphazene vesicles is reported. First, three polyphosphazenes with different amino content were synthesized by amidating hydrophobic side groups; these polyphosphazenes could self-assemble into polymersomes with similar particle size and morphology. Based on FTIR analysis, hydrogen bonding interactions between the polymeric carriers and carboplatin were validated and shown to predominantly contribute to the significant improvement of drug loading in polymersomes. Therefore, it turned out that the amino level of polymers played a substantial role in carboplatin encapsulation. Then, PEAP-2-C polymersomes were optimized for further experimental verification to achieve depressed carboplatin-induced myelotoxicity as well as promote curative effects against CT-26 colon adenocarcinoma. These results in vitro and in vivo proved that amino-functionalized polyphosphazene vesicles have great potential for carboplatin delivery in the application of cancer therapy.

Objectives This study aimed to evaluate that the polymersomes (Ps-DOX-CA4P) dual-loaded with combretastatin-A4 phosphate (CA4P) and doxorubicin (DOX) overcame drug resistance and sensitized tumour cells to chemotherapeutic drugs. Methods Ps-DOX-CA4P were prepared by solvent evaporation method using mPEG-b-PLA as carriers. The potential capability of CA4P to reverse DOX resistance was verified by cytotoxicity test, apoptosis assay and cellular uptake of DOX. The comparison between free drugs and drug-loaded polymersomes was also made on a single-layer cell model and multicellular tumour spheroids to display the superiority of the drug vehicles. Furthermore, we put the emphasis on the investigation into underlying mechanisms for CA4P overcoming DOX resistance. Key findings Results showed Ps-DOX-CA4P achieved increased uptake of DOX, enhanced cytotoxicity and apoptotic rate in MCF-7/ADR cells as well as MCF-7/ADR tumour spheroids. The potential molecular mechanisms may be related to inhibiting P-glycoprotein function by downregulating protein kinase Cα, stimulating ATPase activity, depleting ATP and increasing intracellular reactive oxygen species levels. Conclusions The findings validated the sensitization property of CA4P on DOX independent of its well-known angiogenesis effect, which would provide a novel and promising strategy for drug-resistant cancer therapy.

Aim: In this study, we constructed a novel vector (BioPf-M-loaded Alg-microparticles [Alg-BioPf-M]) with nano-in-micro structure to improve the oral absorption of docetaxel (DTX) by sequentially dual-targeting functions toward intestine and sodium-dependent multivitamin transporter based on entrapping biotin-modified micelles into alginate microparticles. Methods: A series of characteristics of this system was investigated, such as drug release, cellular uptake, transport pathway and the comprehensive in vivo studies including pharmacokinetic studies, anti-tumor activity and toxicity study. Results: The bioavailability of DTX-loaded Alg-BioPf-M was 27.4-fold higher than that of free DTX after oral administration and achieved superior tumor inhibition of 84.6% against sarcoma 180 tumors. Conclusion: These results demonstrated that the Alg-BioPf-M was a promising vector for oral delivery of DTX.

MiR-200c has been confirmed to display remarkable effects on proliferation inhibition and apoptosis induction of certain cancer cells, but the main challenge for its successful translation into the clinic remains its effective delivery to the action site in vivo. In this study, a novel composite polyphosphazene vesicle system composed of amphiphilic [NP(PEG)0.3(EAB)1.7]n (PEEP) and weakly cationic [NP(PEG)0.5(DPA)1.5]n (PEDP) was prepared via a very simple dialysis method. The loading of miR-200c was accomplished with high efficiency by taking advantage of the combination effect of physical encapsulation and electrostatic interaction between vectors and miR-200c. The resultant miR-200c-loaded PEEP-PEDP polymersome (Nano-ED-200c) displayed suitable particle size, electric neutrality, excellent Ribonuclease stability and hemocompatibility. We also evaluated its subsequent miR-200c function in paclitaxel resistance human lung cancer (A549/T) cells in culture and tumor xenografts in nude mice. The results showed that Nano-ED-200c could achieve a higher miR-200c level and the enhanced antitumor efficacy with 68% tumor inhibition ratio at a very low dose of 1.0 mg/kg than PEEP nanoparticle, PEDP nanoparticle, even than Lipo2000. All these evidences indicated that this miR-200c delivery via polyphosphazene vesicles could act as a potential new therapeutic option for paclitaxel resistant human lung cancer.

Understanding how the size of nanocarriers affects their fate in biological systems in vivo is of fundamental importance for rational design of drug delivery systems. In this study, five docetaxel (DTX)-loaded methoxy poly(ethylene glycol)-poly(lactide) micelles of different sizes (30-230nm) were prepared. It was observed that the permeation of micelles within both the multicellular tumor spheroids and tumor xenografts in mice was dependent on the size of the micelle. In addition, the size of micelles influenced their pharmacokinetic behavior. DTX-loaded pH-sensitive micelle based on poly(ethylene glycol)-poly(lactide)-poly(β-amino ester) (DTX-pHPM) was constructed to further illustrate the effect of particle size. As expected, DTX-pHPM improved tumor penetration, uptake by tumor cells, and prolonged circulation time, consequently demonstrating the highest inhibition of in vivo tumor growth (84.4%) in oral epidermoid carcinoma. Taken together, our findings can aid in designing nano-scale drug delivery systems for cancer therapy by optimizing the particle size.

Lu Zhang,1–3 Jiafei Lu,3 Liyan Qiu1 1Ministry of Education (MOE) Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, 2Drug Clinical Trial Office, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, 3College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, People’s Republic of China Abstract: P-glycoprotein (P-gp) overexpression has become the most common cause of occurrence of multidrug resistance in clinical settings. We aimed to construct a micellar polymer carrier to sensitize drug-resistant tumors to doxorubicin (DOX). This A-B-C-type amphiphilic copolymer was prepared by the sequential linkage of β-cyclodextrin, hydrophobic poly(D,L-lactide), and hydrophilic poly(ethylene glycol). Upon incubation of the DOX-loaded micelles with DOX-resistant human breast carcinoma MCF-7/ADR cells, significantly enhanced cytotoxicity and apoptosis were achieved. A series of studies on the action mechanism showedthat the polymer components such as β-cyclodextrin, hydrophobic poly(D,L-lactide) segment, and poly(ethylene glycol) coordinatively contributed to the improved intracellular ATP depletion and ATPase activity, increased intracellular uptake of P-gp substrates via competitive binding to P-gp, and decreased P-gp expression in MCF-7/ADR cells. More interestingly, a similar phenomenon was observed in the zebrafish xenograft model, resulting in ~64% inhibition of MCF-7/ADR tumor growth. These results implied that the polymeric micelles displayed great potentials as P-gp modulators to reverse DOX resistance in MCF-7/ADR breast carcinoma. Keywords: multidrug resistance, P-glycoprotein, micelle, doxorubicin, zebrafish

Abnormal lipid metabolism is a hallmark of tumorigenesis. Accumulating evidence demonstrates that fatty acid synthase (FAS, FASN) is a metabolic oncogene that supports the growth and survival of tumor cells and is highly expressed in many cancers. Here, we report that the oncoprotein, hepatitis B X-interacting protein (HBXIP, LAMTOR5) contributes to abnormal lipid metabolism. We show that high expression of HBXIP in 236 breast cancer patients was significantly associated with decreased overall survival and progression-free survival. Interestingly, the expression of HBXIP was positively related to that of FAS in clinical breast cancer tissues, and HBXIP overexpression in breast cancer cells resulted in FAS upregulation. Mechanistically, HBXIP upregulated SREBP-1c (SREBF1), which activates the transcription of FAS, by directly interacting with and coactivating nuclear receptor (NR) liver X receptors (LXR). Physiologically, LXRs are activated via a coactivator containing NR motif in a ligand-dependent manner. However, in breast cancer cells, HBXIP containing the corepressor/nuclear receptor motif with special flanking sequence could coactivate LXRs independent of ligand. Moreover, overexpressed SREBP-1c was able to activate the transcription of HBXIP, forming a positive-feedback loop. Functionally, HBXIP enhanced lipogenesis, resulting in the growth of breast cancer cells in vitro and in vivo. Thus, we conclude that the oncoprotein HBXIP contributes to the abnormal lipid metabolism in breast cancer through LXRs/SREBP-1c/FAS signaling, providing new insights into the mechanisms by which cancer cells reprogram lipid metabolism in their favor. Cancer Res; 76(16); 4696–707. ©2016 AACR.

Chemotherapy is one of the main strategies for cancer treatment, but its effective application is seriously limited by the development of drug resistance. In this study, we designed micellar vectors for doxorubicin based on amphiphilic copolymers sequentially linking β-cyclodextrin (β-CD), polylacticacid (PLA) or polycaprolactone (PCL) block, and polyethylene glycol (PEG) block to overcome drug resistance in human acute myeloid leukemia cells (HL60/ADR) overexpressing multidrug resistance protein 1 (MRP1). The significant enhancement in cytotoxicity and inhibited HL60/ADR tumor growth in mouse was achieved. More importantly, several analyses were performed to understand the interactions between various polymers and MRP1 at the cellular level. The results showed that the polymers did not show remarkable correlation of MRP1 gene and protein expression, but could decrease intracellular ATP, mitochondrial membrane potential and glutathione levels, which was greatly dependent on the molecular structure of polymers. In conclusion, these novel micelles can be considered as a kind of promising drug delivery system for tumor therapy to reverse drug resistance related to MRP1 overexpression.

Polymersomes represent a promising pharmaceutical vehicle for the delivery of hydrophilic therapeutic agents. However, modification of polymersomes with molecules that confer targeting functions remains challenging because of the strict requirements regarding the weight fractions of the hydrophilic and hydrophobic block polymers. In this study, based on the compatibility between cholesterol and polymeric carriers, polymersomes self-assembled by amphiphilic graft polyphosphazenes were endowed with a targeting function by incorporating the cholesterol-linked aptamer through a simple dialysis method. The aqueous interior of the polymersomes was employed to encapsulate water-soluble doxorubicin hydrochloride. In vivo experiments in tumor-bearing mice showed that the aptamer-anchored vesicle targeted accumulation at the tumor site, favorable penetration through tumor tissue, and incremental endocytosis into tumor cells. Correspondingly, the aptamer-anchored vesicle decreased systemic toxicity and effectively suppressed the growth of subcutaneous MCF-7 xenografts. These findings suggested that vesicles modified with targeted groups via hydrophobic supermolecular interactions could provide a platform for selective delivery of hydrophilic drug. Statement of Significance Polymersomes have represented a promising type of pharmaceutical vehicles due to their predominant physical properties. However, it is still a challenge to endow polymersomes with active target function because of strict requirements of the weight fractions of hydrophilic polymer block to hydrophobic one. In this research, by taking advantage of the supermolecular interactions between amphiphilic graft polyphosphazene and cholesterol which was linked to aptamer AS1411, we prepared a targeted functional polymersome (PEP-DOX·HCl-Ap) through a simple method with high loading of water soluble anti-cancer drug doxorubicin hydrochloride. The in vivo experiments in MCF-7 tumor-bearing mice demonstrated several advantages of PEP-DOX·HCl-Ap vesicle such as prolonged circulation time in blood, targeted accumulation at tumor site, permeation through the tumor tissue and incremental endocytosis by tumor cells, which consequently resulted in the significantly improved anti-cancer efficacy. Moreover, this novel polymersome designed in this study has built a research platform to achieve targeted delivery of hydrophilic chemotherapeutics for cancer therapy.

The conventional chemotherapeutic agent doxorubicin hydrochloride (DOX·HCl) is often accompanied by drug resistance which has severely hindered its clinical application. By taking advantage of the self-assembled behavior of amphiphilic polyphosphazenes, we constructed novel polymersomes loading DOX·HCl or desalted DOX with chloroquine phosphate (CQ) as a drug resistance-reversal agent at 1:1 or 2:1 weight ratios via a one-step common dialysis method. The cytotoxicity evaluation of this dual drug-loaded polymersome was performed on DOX-resistant MCF-7/Adr breast cancer and HL60/Adr leukemia cells. Simultaneously, to simulate in vivo cancerous tissue, 3D tumor spheroid was constructed for tissue penetration and anti-cancer effect evaluation. As a result, PEP-DHC-1 containing DOX·HCl and CQ at 1:1 weight ratio exhibited the strongest toxicity. Furthermore, the in vivo tumor inhibition study carried out on a zebrafish xenograft model also validated that PEP-DHC-1 made the outstanding contribution to improve the sensitivity of MCF-7/Adr breast cancer to chemotherapeutics. These findings suggest that this DOX·HCl and CQ co-delivery system based on PEP polymersomes might be promising for drug resistance reversal of cancer therapy and consequently enhanced anti-cancer efficacy.

Spinal muscular atrophy (SMA) is a kind of neuromuscular disease characterized by progressive motor neuron loss in the spinal cord. It is caused by mutations in the survival motor neuron 1 (SMN1) gene. SMN1 has a paralogous gene, survival motor neuron 2 (SMN2), in humans that is present in almost all SMA patients. The generation and genetic correction of SMA patient-specific induced pluripotent stem cells (iPSCs) is a viable, autologous therapeutic strategy for the disease. Here, c-Myc-free and non-integrating iPSCs were generated from the urine cells of an SMA patient using an episomal iPSC reprogramming vector, and a unique crRNA was designed that does not have similar sequences (≤3 mismatches) anywhere in the human reference genome. In situ gene conversion of the SMN2 gene to an SMN1-like gene in SMA-iPSCs was achieved using CRISPR/Cpf1 and single-stranded oligodeoxynucleotide with a high efficiency of 4/36. Seamlessly gene-converted iPSC lines contained no exogenous sequences and retained a normal karyotype. Significantly, the SMN expression and gems localization were rescued in the gene-converted iPSCs and their derived motor neurons. This is the first report of an efficient gene conversion mediated by Cpf1 homology-directed repair in human cells and may provide a universal gene therapeutic approach for most SMA patients.

Aptamers are single-stranded RNA or DNA ligands that can specifically bind to various molecular targets with high affinity. Owing to this unique character, they have become increasingly attractive in the field of drug delivery. In this study, we developed a multifunctional composite micelle (CM) with surface modification of aptamer AS1411 (Ap) for targeted delivery of doxorubicin (DOX) to human breast tumors. This binary mixed system consisting of AS1411 modified Pluronic F127 and beta-cyclodextrin-linked poly(ethylene glycol)-b-polylactide could enhance DOX-loading capacity and increase micelle stability. Cellular uptake of CM-Ap was found to be higher than that of untargeted CM due to the nucleolin-mediated endocytosis effect. In vivo study in MCF-7 tumor-bearing mice demonstrated that the AS1411-functionalized composite micelles showed prolonged circulation time in blood, enhanced accumulation in tumor, improved antitumor activity, and decreased cardiotoxicity. In conclusion, aptamer-conjugated multifunctional composite micelles could be a potential delivery vehicle for cancer therapy.

Breast cancer remains one of the most common cancers for females. Drug delivery based on cancer nanotechnology could improve the performance of some chemotherapeutic medicines already used in clinic. The emergence of polymersomes provided the potential to encapsulate hydrophobic/hydrophilic drugs. By modifying the weight ratio of methoxy-poly (ethylene glycol) (mPEG) chain to ethyl-p-aminobenzoate (EAB) side group, a series of amphiphilic graft polyphosphazenes (PEPs) was prepared. PEP can be tuned from micelles to polymersomes with the decrease of mPEG content via dialysis. Either hydrophilic doxorubicin hydrochloride (DOX·HCl) or hydrophobic doxorubicin base (DOX) could be encapsulated into PEP polymersomes with high payload and high encapsulation efficiency due to the strong intermolecular interaction with PEP. Compared with free DOX·HCl administration, in vivo investigation in growth inhibition of MCF-7 xenograft tumors in nude mice demonstrated that PEP polymersomes could enhance life safety without compromise of therapeutic efficacy, especially DOX·HCl loaded delivery system. From the Clinical Editor In this preclinical study, polymerosomes based on PEPs were investigated as doxorubicin delivery systems, demonstrating similar efficacy but less toxicity compared to standard delivery methods.

The transmembrane transport of drug loaded micelles to intracellular compartment is quite crucial for efficient drug delivery. In the current study, we investigated the cellular internalization and anticancer activity of doxorubicin loaded micelles with folate modified stealthy PEOz corona. Folate-decorated micelles incorporating doxorubicin were characterized for particle size, degree of folate decoration, drug loading content and encapsulation efficiency, morphology, and surface charge. The targeting capability and cell viability were assessed using HeLa, KB, A549 and MCF-7/ADR cell lines. In vitro study clearly illustrated the folate receptor (FR) mediated targeting of FA modified micelles to FR-positive human HeLa, KB and MCF-7/ADR cells, while specific delivery to FR-negative A549 cells was not apparently increased at the same experimental conditions. Cytotoxicity assay showed 60% and 58% decrease in IC50 values for HeLa and KB cells, while only a slight decrease for A549 cells, following treatment with folate modified formulations. The enhanced intracellular delivery of FA modified micelles in MCF-7/ADR cells was also observed. In vivo antitumor tests revealed DOX entrapped FA-PEOz-PCL micelles effectively inhibited the tumor growth and reduced the toxicity to mice compared with free DOX. The current study showed that the targeted nano-vector improved cytotoxicity of DOX and suggested that this novel PEOz endowed stealthy micelle system held great promise in tumor targeted therapy.

Multidrug resistance (MDR) is a major obstacle to successful clinical cancer chemotherapy. Currently, there is still unsatisfactory demand for innovative strategies as well as effective and safe reversing agent to overcome MDR. In this study, we developed a novel nanoformulation, in which doxorubicin hydrochloride (DOX) and quinine hydrochloride (QN) were simultaneously loaded into liposomes by a pH-gradient method for overcoming MDR and enhancing cytotoxicity in a doxorubicin-resistant human breast cancer cell line (MCF-7/ADR). The various factors were investigated to optimize the formulation and manufacturing conditions of DOX and QN co-loaded liposomes (DQLs). The DQL showed uniform size distribution and high encapsulation efficiency (over 90%) for both the drugs. Furthermore, DQLs significantly displayed high intracellular accumulation and potential of MDR reversal capability in MCF-7/ADR cells through the cooperation of DOX with QN, in which QN played the role as a MDR reversing agent. The IC50 of DQL0.5:1 with the DOX/QN/SPC weight ratio of 0.5:1:50 was 1.80 ± 0.03 μg/mL, which was 14.23 times lower than that of free DOX in MCF-7/ADR cells. And the apoptotic percentage induced by DQL0.5:1 was also increased to 62.2%. These findings suggest that DQLs have great potential for effective treatment of MDR cancer.

Adenosine triphosphate (ATP)-binding cassette (ABC) transporters play a key role in the development of multidrug resistance (MDR) in cancer cells. P-glycoprotein (P-gp) and multidrug resistance-associated protein 1 (MRP1) are important proteins in this superfamily which are widely expressed on the membranes of multidrug resistance (MDR) cancer cells. Besides, upregulation of cellular autophagic responses is considered a contributing factor for MDR in cancer cells. We designed a liposome system co-encapsulating a chemotherapeutic drug (doxorubicin hydrochloride, DOX) and a typical autophagy inhibitior (chloroquine phosphate, CQ) at a weight ratio of 1:2 and investigated its drug resistance reversal mechanism. MTT assay showed that the IC

To circumvent the severe toxicity of the systemic delivery of IL-12 protein and the limits of local administration of IL-12 gene, we constructed a polymersome system for systemic delivery of recombinant murine IL-12 plasmid (pmIL-12) based on amphiphilic polyphosphazenes containing weakly cationic N,N-diisopropylethylenediamine (DPA) as hydrophobic groups and monomethoxy poly(ethylene glycol) (mPEG) as hydrophilic tails. By simple dialysis method, pmIL-12 was successfully loaded into polymersomes due to the combination effect of physical encapsulation and electrostatic interaction. This pmIL-12 polymersome delivery system was validated with good biocompatibility and stability despite of serum protein and DNase challenging. The results of in vivo antitumor experiments showed that intravenous injection of pmIL-12 polymersomes achieved significant suppression of tumor growth in BALB/c mice bearing CT-26 colon carcinoma. The analysis revealed that the mechanism was related to the antitumor immune response induced by efficient transfection of pmIL-12 polymersomes, which maybe involved lymphocytes infiltration and angiogenic inhibition at the tumor site.

Doxorubicin, as a widely used chemotherapeutic, always causes multidrug resistance in human cancer cells. To circumvent drug resistance, we developed a novel formulation where doxorubicin hydrochloride (DOX) and chloroquine phosphate (CQ) were simultaneously loaded into liposomes by a pH-gradient method where CQ played the role of a chemical sensitizer. The various factors were investigated to optimize the formulation and manufacturing conditions of DOX and CQ coencapsulated liposomes (DCL). The resultant DCLs achieved the high encapsulation efficiency of both drugs over 90%. Further, DCLs significantly displayed resistance reversal action on a doxorubicin-resistant human breast cancer cell line (MCF-7/ADR) through the cooperation of CQ with DOX. The reversal fold of DCL with the DOX/CQ/soybean phosphatidylcholine weight ratio of 0.5:1:50 was 5.7, compared to free DOX. These results demonstrate that DCL is a promising formulation for the treatment of DOX-resistant breast cancer.

Emerging evidence has shown that hepatitis B virus (HBV) X protein (HBx) plays a crucial role in the development of hepatocellular carcinoma. Complement regulatory proteins including CD46, CD55 and CD59 contribute to escape of tumor cells from complement-dependent cytotoxicity (CDC). However, little is known about the potential role of HBx in anti-CDC activity during hepatocarcinogenesis. In the present study, we for the first time report that HBx decreases the sensitivity of hepatoma and hepatic cells to CDC. Coincidentally, we demonstrated that HBx increased the promoter activity of CD59, as well as their messenger RNA and protein levels. Moreover, flow cytometry showed the increased expression level of CD59 protein on the surface of HBx-positive cells. Of interest, we found that HBx up-regulated CD59 by binding with cAMP response element-binding to the promoter region of the CD59 gene using chromatin immunoprecipitation assay. In addition, we showed that HBx up-regulated CD59 by let-7i at post-transcriptional regulation level. Our data showed that the deposition of C5b-9 were decreased on the cell surface in HepG2-X cells relative to HepG2 cells, suggesting that increased CD59 mediated by HBx prevents the formation of functional membrane attack complex. Furthermore, we demonstrated that down-regulation of CD59 was sufficient to abolish the resistance capability of CDC in HBx-positive cells by RNA interference (siRNA) in vitro and in vivo. Thus, we conclude that HBx contributes to cells resistance to CDC through CD59. Therapeutically, CD59 may serve as a target in HBV-associated hepatoma patients.

Hepatitis B virus X protein (HBx) plays a crucial role in the development of hepatocellular carcinoma. Here, we sought to identify the mechanisms by which HBx mediates liver cell proliferation. We found that HBx upregulated the levels of cyclooxygenase-2 (COX-2), 5-lipoxygenase (5-LOX) and phosphorylated extracellular signal-regulated protein kinases 1/2 (p-ERK1/2) in liver cells. HBx-induced p-ERK1/2 was abolished by inhibition of Gi/o proteins, COX or LOX. In addition, HBx increased the amounts of prostaglandin E2 (PGE2) and leukotriene B4 (LTB4) released from cell lines derived from hepatocytes. Moreover, these released arachidonic acid metabolites were able to activate ERK1/2. Interestingly, activated ERK1/2 could upregulate the expression of COX-2 and 5-LOX in a positive feedback manner. In conclusion, HBx enhances and maintains liver cell proliferation via a positive feedback loop involving COX-2, 5-LOX, released arachidonic acid metabolites, Gi/o proteins and p-ERK1/2.

PLAA (ortholog of yeast Doa1/Ufd3, also know as human PLAP or phospholipase A2-activating protein) has been implicated in a variety of disparate biological processes that involve the ubiquitin system. It is linked to the maintenance of ubiquitin levels, but the mechanism by which it accomplishes this is unclear. The C-terminal PUL (PLAP, Ufd3p, and Lub1p) domain of PLAA binds p97, an AAA ATPase, which among other functions helps transfer ubiquitinated proteins to the proteasome for degradation. In yeast, loss of Doa1 is suppressed by altering p97/Cdc48 function indicating that physical interaction between PLAA and p97 is functionally important. Although the overall regions of interaction between these proteins are known, the structural basis has been unavailable. We solved the high resolution crystal structure of the p97-PLAA complex showing that the PUL domain forms a 6-mer Armadillo-containing domain. Its N-terminal extension folds back onto the inner curvature forming a deep ridge that is positively charged with residues that are phylogenetically conserved. The C terminus of p97 binds in this ridge, where the side chain of p97-Tyr(805), implicated in phosphorylation-dependent regulation, is buried. Expressed in doa1Delta null cells, point mutants of the yeast ortholog Doa1 that disrupt this interaction display slightly reduced ubiquitin levels, but unlike doa1Delta null cells, showed only some of the growth phenotypes. These data suggest that the p97-PLAA interaction is important for a subset of PLAA-dependent biological processes and provides a framework to better understand the role of these complex molecules in the ubiquitin system.

The excellent transfection efficiency and viability are essential for successful gene therapy. It suggested that when bound to its glucocorticoid receptor, glucocorticoid steroid can dilate the nuclear pore complexes and facilitated the transport of pDNA into the nucleus. In this research, the two different degrees of substitution of PAMAM-triamcinolone acetonide (PAMAM-TA) conjugates were synthesised for efficient translocation of pDNA into the nucleus. The physicochemical properties of the polyplexes were investigated by agarose gel electrophoresis, Zeta-sizer and TEM. They both could form nano-size polyplexes with pDNA. The polyplexes were very stable and showed excellent buffering capacities, facilitating endosomal escape, and no obvious difference was found between them. The TA-conjugated PAMAM-mediated transfection of luciferase and EGFP genes showed better transfer activity than native PAMAM and was comparable to the PEI 25K (polyethylenimine), and lower cytotoxicity in HEK 293 and HepG 2 cells. Even with 10% serum, their transfer activity was still high relatively. In addition, confocal microscopy examination confirmed that the enhancing mechanism for enhanced gene transfer activity of PAMAM-TA conjugate may involve the nuclear translocation of the polyplex. The low substituted degree of TA to 0.22 did not interrupt its nuclear localization potency. These findings demonstrated that the TA-grafted PAMAM dendrimer is a potential candidate as a safe and efficient gene delivery carrier for gene therapy.

Efficient nuclear gene delivery is essential for successful gene therapy. It was previously reported that the transport of DNA into nucleus may be facilitated by glucocorticoid (GC). In this study, five glucocorticoids with different structures and potencies were conjugated with low molecular weight PEI 1800, and the degree of substitution of glucocorticoids was controlled to be close to each other. The glucocorticoid–polyethylenimine (GC–PEI)/pDNA complexes were prepared and their physico-chemical properties and transfection efficiency were investigated. The results showed that the complexes had similar physico-chemical properties, but their transfection activities were different statistically. In order to explore the reason of this difference, the affinity of GC–PEI polymer with GC receptor was analyzed by the application of molecular docking, and the correlation between transfection activity and the potency of five GC was investigated. The result showed that receptor binding of five GC was different and transgene expression enhanced linearly with the increasing GC potency, but log P . In addition, confocal microscopy examination confirmed that GC–PEI/DNA complexes were more effectively translocated in the nucleus than PEI 25 K or PEI 1800 complexes and the cytotoxicities of the GC–PEI polymers were lower than that of PEI 25 K. These results demonstrated that transfection activity of GC–PEI polymer correlated with its GC potency, and this regularity might be useful for the development of more efficient GC substituted polymer as promising nuclear-targeting carrier.

In this study, a new class of amphiphilic methoxy-poly(ethylene glycol) grafted polyphosphazene with glycine ethyl ester side groups (PPP-g-PEG/GlyEt) was synthesized and characterized. An anti-cancer agent doxorubicin (DOX) was encapsulated into polymeric micelles derived from those copolymers, which exhibited considerably strong impact on micelle morphology: turned the rod-like and spherical drug free micelles into spheres and vesicles respectively. The in vitro release behavior of those drug-loaded micelles exhibits a sustained release manner and is affected by drug content. Cytotoxicity assay against adriamycin-resistant human breast cancer MCF-7 cell line showed that drug-loaded micelles based on PPP-g-PEG/GlyEt micelles can effectively suppress cell proliferation and the cytotoxicity was both time and concentration related, an enhanced cytotoxicity was observed either with increasing drug concentration or with prolonged incubation time. Moreover, flow cytometry results revealed a particle size dependency in cellular uptake of drug-loaded micelles. These findings suggest that the present copolymers can encapsulate water insoluble anti-cancer agents and contribute to improve drug sensitivity of adriamycin-resistant cell line.

To construct novel doxorubicin-loaded polymeric micelles based on polyphosphazenes containing N-isopropylacrylamide copolymers and evaluate their various properties as well as in vitro anticancer effect.These amphiphilic graft polyphosphazenes PNDGP were synthesized via thermal ring-opening polymerization and subsequent two-step substitution reaction of hydrophilic and hydrophobic side groups. Micellization behavior in an aqueous phase was confirmed by fluorescence technique, DLS and TEM. Doxorubicin (DOX) was physically loaded into micelles by dialysis or O/W emulsion method. CLSM and MTT test were applied to observe intracellular drug distribution and determine cytotoxicity of drug-loaded micelles on Hela and HepG2 cells lines, respectively.A series of PNDGPs with controlled substitution ratios were obtained. Poly(NIPAm-co-DMAA) can act as hydrophilic segments in micellular system since its LCST was over 37 degrees C when PNIPAm was copolymerized with DMAA. The CMC value was decreased with the increase of Glyet content. In addition, more hydrophobic group content introduced into the polymer would facilitate DOX encapsulation into the micelle. DOX-loaded micelle could achieve comparative cytotoxicity as free drug via endocytosis and succedent drug release into cytoplasm of cancer cells.The results suggest that these polymers might be used as potential carriers of hydrophobic anti-tumor drug for cancer therapy.

In this study, we designed biodegradable polymersomes for co-delivery of an antiangiogenic drug combretastatin-A4 phosphate (CA4P) and doxorubicin (DOX) to collapse tumor neovasculature and inhibit cancer cell proliferation with the aim to achieve synergistic antitumor effects. The polymersomes co-encapsulating DOX and CA4P (Ps-DOX-CA4P) were prepared by solvent evaporation method using methoxy poly(ethylene glycol)-b-polylactide (mPEG-PLA) block copolymers as drug carriers. The resulting Ps-DOX-CA4P has vesicles shape with uniform sizes of about 50 nm and controlled co-encapsulation ratios of DOX to CA4P. More importantly, Ps-DOX-CA4P (1:10) showed strong synergistic cytotoxicity (combination index CI = 0.31) against human nasopharyngeal epidermal carcinoma (KB) cells. Furthermore, Ps-DOX-CA4P accumulated remarkably in KB tissues xenografts in nude mice. Consistent with these observations, Ps-DOX-CA4P (1:10) achieved significant antitumor potency because of fast tumor vasculature disruption and sustained tumor cells proliferation inhibition in vivo. The overall findings indicate that co-delivery of an antiangiogenic drug and a chemotherapeutic agent in polymersomes is a potentially promising strategy for cancer therapy.

Aim: Indocyanine green (ICG) is a promising near-infrared (NIR) dye for tumor imaging and photothermal therapy; however, the poor stability and lack of targeting limit its application. In this study, ICG was encapsulated into folate-conjugated poly(2-ethyl-2-oxazoline)-b-poly(ε-caprolactone) micelles to overcome these problems. Materials & methods: ICG-loaded micelles were prepared by solvent evaporation method. Cell uptake and in vitro photothermal cytotoxicity were evaluated on KB cells. In vivo NIR imaging and photothermal therapy were conducted on KB tumor-bearing mice. Results: ICG-loaded micelles with favorable sizes and stable NIR optical properties were successfully prepared. These micelles could target to KB tumors and enabled high-resolution NIR imaging. Moreover, they could effectively convert the absorbed NIR laser energy into heat, resulting in significant tumor damage and inhibition. Conclusion: This novel micellar system, integrating stable NIR properties, excellent tumor targeting and photothermal capability, showed great potential in tumor imaging and therapy.

In order to enhance the antitumor effects of doxorubicin (DOX), a novel micellar vector with high DOX loading and tumor targeting function based on folate-conjugated amphiphilic copolymer folate-poly(ethylene glycol)-poly(d,l-lactide)-β-cyclodextrin (FA-PEL-CD) was constructed. Cytotoxicity and cellular uptake experiments were performed in HeLa, KB, and A549 cell lines expressing different amounts of folate receptors in order to evaluate the targeting effect of the folate modification. The antitumor experiments performed in a KB cell-xenografted nude mouse model showed that the treatment with 10mg/kg DOX loaded FA-PEL-CD micelles achieved approximately 86% of tumor growth inhibition compared to the control. Ex vivo fluorescence imaging experiments and histological examination confirmed that folate modification can enhance the antitumorigenesis efficacy and reduce the cardiotoxicity of DOX. These results suggest that FA-PEL-CD copolymer-based micelles are promising nanocarriers for targeted doxorubicin delivery, with improved antitumor efficacy and reduced toxicity in normal tissues.

Modifying positive surface charge and reducing bulk size of nanoparticles has been proven beneficial to cancer cellular delivery, but meanwhile results in fast clearance and unspecific distribution in body after intravenous injection. How to balance these problems is still a challenge to construct an ideal nano-scaled drug delivery system in cancer treatment. Herein, we developed a multistage drug delivery system to enhance anticancer efficacy of curcumin (CUR), which could intelligently alter its size and surface charge after long-circulation and extravasation from leaky blood vessels at tumor sites. This micellar system was constructed by amphiphilic and pH-sensitive methoxy poly(ethylene glycol)-poly(lactide)-poly(β-amino ester) (MPEG-PLA-PAE) copolymers. As compared with MPEG-PLA micelles, MPEG-PLA-PAE micelles displayed several advantageous characteristics for drug delivery and treatment. We found that CUR-loaded MPEG-PLA-PAE micelles remained stable in murine plasma at 37 °C even with high drug loading. More interestingly, when the media pH decreased from 7.4 to 5.5, the micelles shrank from 171.0 nm to 22.6 nm and their surface charge increased to 24.8 mV meanwhile, which resulted in the significantly improved cell uptake of CUR by human breast cancer MCF-7 cells. Using indocyanine green (ICG) as a fluorescence probe, it was observed that MPEG-PLA-PAE micelles experienced longer circulation than MPEG-PLA micelles followed by accumulation at tumors with stronger fluorescence intensity. Consequently, MPEG-PLA-PAE micelles achieved enhanced cancer growth inhibition of 65.6% in vivo. All these findings demonstrated the potential of size/charge-changing MPEG-PLA-PAE micelles as a promising drug delivery system for tumor-targeted therapy.

Aptamers are a class of oligonucleotides that can specifically bind to different targets with high affinity. Since their discovery in 1980s, aptamers have attracted considerable interests in medical applications. So far, initial research using aptamers as delivery systems has produced exciting results. In this review, we summarize recent progress in aptamer-mediated chemotherapeutic drug and siRNA delivery systems in tumor treatment. With regard to chemotherapeutic drugs, the 2 main methods for targeted delivery using aptamers are as follows: aptamer-drug systems (in which aptamers directly deliver the drug both as a carrier and as a ligand) and aptamer-nanoparticles systems (in which nanoparticles function together with aptamers for targeted delivery of drugs). For delivery of siRNA, aptamers can be utilized by the following ways to facilitate targeting: (1) linked by a connector; (2) form a chimera; and (3) combined with nanoparticles. In co-delivery system, the advantages associated with the use of aptamers are beginning to become apparent also. Here, the challenges and new perspectives in the field of aptamer-mediated delivery have been discussed.

The significance of hepatitis B virus (HBV) DNA-based integration in hepatocarcinogenesis is poorly understood. In the present study, we investigated whether the integration of HBV X gene (HBx) is involved in the event. Our finding showed that the integration of HBx fragment (316–462bp/262–462bp) was able to transform human immortalized normal liver LO2 cells using a cell model of HBx-integration. We identified that the recombination, HBx/Alu core sequence/subtelomeric DNA, was required for the transformation, which could be detected in 5 out of 44 clinical HBx-positive hepatocellular carcinoma tissues. Thus, we conclude that HBx integration is involved in the hepatocarcinogenesis.

pH-responsive drug carriers derived from polymers containing weak base groups have been shown to improve the antitumor effect of chemotherapeutics. The common interpretation is that a "proton sponge effect" caused by pH-responsive polymers facilitates endosomal membrane destruction and accelerates cytoplasmic drug release in tumor cells. However, the mechanisms by which pH-responsive weak base polymers disrupt membranes have not been expatiated clearly. Herein, we synthesized a series of pH-responsive amphiphilic polyphosphazenes containing diisopropylamino (DPA) side groups with various contents and investigated the effect of DPA content on the actions of polymers with cell membranes. In a certain pH range, the polymers with elevated DPA content showed enhanced membrane disruptive activity. Electrical interactions between the protonated DPA groups of polymers and the cell lipid bilayer are critical for pH-dependent membrane disruption, which can be competitively prevented by serum proteins. On the other hand, the hydrophobic unprotonated DPA moieties can insert into lipophilic regions of cell membrane. These synergic actions caused the alteration of biomembrane permeability consequently. More interestingly, it was also found that DPA-rich polymers exhibit higher P-glycoprotein (P-gp) inhibition activity as compared with the polymer containing only low levels of DPA by efficiently blocking the internal epitope of P-gp. These findings strongly provide rational support for pH-responsive amphiphilic polyphosphazenes containing DPA side groups to be quite promising drug carriers for intracellular drug delivery applications, especially the treatment of P-gp overexpressing, drug-resistant tumors.

Background Mucosa-associated lymphoid tissue 1 (MALT1) plays an important role in the adaptive immune program. During TCR- or BCR-induced NF-κB activation, MALT1 serves to mediate the activation of the IKK (IκB kinase) complex, which subsequently regulates the activation of NF-κB. Aggregation of MALT1 is important for E3 ligase activation and NF-κB signaling. Principal Findings Unlike the isolated CARD or paracaspase domains, which behave as monomers, the tandem Ig-like domains of MALT1 exists as a mixture of dimer and tetramer in solution. High-resolution structures reveals a protein-protein interface that is stabilized by a buried surface area of 1256 A2 and contains numerous hydrogen and salt bonds. In conjunction with a second interface, these interactions may represent the basis of MALT1 oligomerization. Conclusions The crystal structure of the tandem Ig-like domains reveals the oligomerization potential of MALT1 and a potential intermediate in the activation of the adaptive inflammatory pathway. Enhanced version This article can also be viewed as an enhanced version in which the text of the article is integrated with interactive 3D representations and animated transitions. Please note that a web plugin is required to access this enhanced functionality. Instructions for the installation and use of the web plugin are available in Text S1.

This study involved the construction of self-assembled nanoparticles from novel pH-sensitive amphiphilic polyphosphazenes. These nanoparticles provide fast pH-responsive drug release and have the capability to disturb endosomal membranes. The polymers were prepared by linking N,N-diisopropylethylenediamine (DPA) onto a backbone of PEGylated polyphosphazene. In vitro cell viability measurements demonstrated the superior efficacy of these pH-responsive nanoparticles over free doxorubicin (Dox): the IC50 was over 60 times lower than that of free Dox against a Dox-resistant cell line. Using flow cytometry and confocal microscopy, the further investigation of the intracellular distribution of Dox and fluorescent probes provided evidence that, upon internalization by cells through endocytic pathways, the pH-sensitive polymer would disrupt membranes of endosomal compartments, releasing the cargo drugs into the cytoplasm in a burst-like manner. This resulted in reduced likelihood of drug efflux via exocytosis, and reversal of the drug resistance of the tumor cells. Generally, the pH-responsive nanoparticles designed in this study have achieved their potential as a drug delivery system for tumor therapy applications.

This study constructed a series of novel micelles based on star-shaped amphiphilic copolymers (sPEC/CDs), and aimed to confirm the important role poly(e-caprolactone) (PCL) segments played to improve the various properties of micelles. sPEC/CDs, consisting of β-cyclodextrin (β-CD) as a core and monomethoxy poly(ethylene glycol) (mPEG) and PCL diblock copolymers as arms, were synthesized by arm-first method. The critical micelle concentrations (CMC) of sPEC/CDs were determined by fluorescence spectrophotometry using pyrene as a probe. 3-(4, 5-dimethylthiazol-2-yl)- 2,5-diphenyltetrazolium bromide and flow cytometry were used to detect drug cytotoxicity and cellular uptake of the doxorubicin-loaded micelles. Rhodamine-123 cellular accumulation was examined to evaluate the polymer action to P-glycoprotein. It was revealed that, once PCL segment was inserted between β-CD and mPEG, the CMC can be significantly decreased, the drug loading capability greatly improved, and the drug resistance of MCF-7/ADR cells effectively reversed. These findings suggest that sPEC/CDs own potential superiority for cancer therapy as drug carriers.

pH-responsive amphiphilic graft macromolecules consisting of a polyphosphazene backbone, hydrophilic PEG branches and pH-sensitive DPA were successfully synthesized and characterized. The copolymer can self-assemble into vesicles in an aqueous solution with unique inner structure and homogeneously encapsulate both lipophilic and hydrophilic molecules. The pH-dependent structure change of vesicles was also observed by DLS and TEM. Dox-loaded vesicles exhibit a sharp pH-responsive drug release profile and dramatically enhance the cytotoxicity of Dox against Dox-resistant MCF-7/adr cells. These results suggest such vesicles based on pH-responsive polyphosphazene hold great potential for specific drug therapy.

Aim: Delivery of doxorubicin could be achieved by a novel micellar system based on β-cyclodextrin-centered star-shaped amphiphilic polymers (sPEL/CD). This study specifically explored the effect of polylactide segments in sPEL/CD on various micelle properties, such as the critical micelle concentration, size, drug loading, cytotoxicity and drug resistance reversing effect. Method: The sPEL/CD was synthesized by the arm-first method. The critical micelle concentrations of polymeric micelles were determined by fluorescence spectrophotometry using pyrene as a probe. The oil/water method was applied to prepare doxorubicin-loaded micelles. 3-(4,5-dimethylthi-azol-2-yl)-2,5-diphenyltetrazolium bromide, confocal laser-scanning microscopy and flow cytometry were used to examine cell cytotoxicity and cellular uptake of the doxorubicin-loaded micelles. Finally, rhodamine-123 cellular uptake was determined to evaluate the polymer action on MCF-7 and MCF-7/ADR cells. Results: All polymers exhibited low cytotoxicity and their micelles had a desirable release-acceleration pH (pH 5.0) for cytoplasmic drug delivery. With the introduction of polylactide into the polymer, the micelle critical micelle concentration can be effectively decreased and the drug-loading content was enhanced. Most importantly, the drug resistance of MCF-7/ADR cells was significantly reversed via the interaction between polymer and Pgp. Therefore, this type of polymer has potential superiority for cancer therapy.

Poly(epsilon-caprolactone)-poly(ethylene glycol) (PCL-PEG) copolymers are important synthetic biomedical materials with amphiphilicity, controlled biodegradability, and great biocompatibility. They have great potential application in the fields of nanotechnology, tissue engineering, pharmaceutics, and medicinal chemistry. This review introduced several aspects of PCL-PEG copolymers, including synthetic chemistry, PCL-PEG micro/nanoparticles, PCL-PEG hydrogels, and physicochemical and toxicological properties.

Hepatitis B virus X protein (HBx) plays a crucial role in the development of hepatocellular carcinoma (HCC). However, the significance of circulating antibody to hepatitis B virus X antigen (anti-HBx) in sera remains unclear. In the present study, we examined the titers of anti-HBx (IgG) in the sera from 173 patients with chronic hepatitis B (CHB), 106 liver cirrhosis (LC), and 61 HCC by enzyme-linked immunosorbent assay (ELISA), respectively. Our data showed that the positive rates of anti-HBx were higher in sera of LC (40.6%) and HCC (34.4%) than those of CHB (10.4%),P<.05. In all 40 patients with anti-HBx+ out of 340 patients, 39 (97.5%) were HBsAg/HBeAg/anti-HBc+ and 1 (2.5%) was anti-HBs+ (P<.01), suggesting that anti-HBx in sera is a marker of HBV replication rather than a protective antibody. Thus, our findings reveal that circulating anti-HBx in sera is one of the markers of development of LC and HCC mediated by HBV.

Self-assembled polymeric micelles are widely applied in drug delivery system (DDS). In this study, honokiol (HK) loaded micelles were prepared from biodegradable poly(epsilon-caprolactone)-poly(ethylene glycol)-poly(epsilon-caprolactone) (PCEC) copolymers. Micelles were prepared by self-assembly of triblock copolymer PCEC in distilled water triggered by its amphiphilic character without any organic solvent. Drug loading and encapsulation efficiency were determined by adjusting the weight ratio of HK and PCEC. The particle size and zeta potential distribution of obtained micelles were determined using Malvern laser particle sizer, and spherical geometry were observed on atomic force microscope (AFM). Otherwise, the thermo-sensitivity of honokiol-loaded micelles was monitored. And the cytotoxicity results of drug loaded micelles showed that the encapsulated honokiol remained potent antitumor effect. Moreover, in vitro release profile demonstrated a significant difference between rapid release of free honokiol and much slower and sustained release of HK-loaded micelles. These results suggested that we have successfully prepared honokiol-loaded micelles in an improved method which is safer and more efficient. The prepared micelles might be potential carriers for honokiol delivery in cancer chemotherapy.

Menghua Gao,1 Yuzhen Xu,1 Liyan Qiu2,3 1College of Pharmaceutical Sciences, 2Ministry of Education (MOE) Key Laboratory of Synthesis and Functionalization, Department of Polymer Science and Engineering, ZhejiangUniversity, Hangzhou, 3Collaborative Innovation Center for Biotherapy, West China Hospital, Sichuan University, Chengdu, People’s Republic of China Abstract: A novel composite liposomal system co-encapsulating paclitaxel (PTX) with chloroquine phosphate (CQ) was designed for treating PTX-resistant carcinoma. It was confirmed that liposomal CQ can sensitize PTX by means of autophagy inhibition and competitively binding with multidrug-resistance transporters. Furthermore, according to the in vitro cytotoxicity and apoptosis assay, real-time observation of cellular uptake, and in vivo tissue distribution study, co-encapsulation of PTX and CQ in liposomes was validated as superior to the mixture of PTX liposome plus CQ liposome due to the simultaneous delivery and synergetic effect of the two drugs. Consequently, this composite liposome achieved significantly stronger anticancer efficacy in vivo than the PTX liposome plus CQ liposome mixture. This study helps to guide and enlighten ongoing and future clinical trials about the optimal administration modes for drug combination therapy. Keywords: paclitaxel, chloroquine, liposome, drug resistance, combination therapy

Yuzhen Xu,1 Liyan Qiu2 1College of Pharmaceutical Sciences, 2Ministry of Education Key Laboratory of Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, People’s Republic of China Abstract: The use of vincristine (VCR) to treat cancer has been limited by its dose-dependent toxicity and development of drug resistance after repeated administrations. In this study, we investigated the mechanism by which quinine hydrochloride (QN) acts as a sensitizer for VCR. Our experiments used three kinds of multidrug-resistant cancer cells and demonstrated that QN worked by inducing intracellular depletion of adenosine triphosphate, increasing adenosine triphosphatase activity, and decreasing P-glycoprotein expression. Based on these results, we designed and prepared a VCR and QN codelivery liposome (VQL) and investigated the effect of coencapsulated QN on the in vitro cytotoxicity of VCR in cells and three-dimensional multicellular tumor spheroids. The antitumor effects of the formulation were also evaluated in multidrug-resistant tumor-bearing mice. The results of this in vivo study indicated that VQL could reverse VCR resistance. In addition, it reduced tumor volume 5.4-fold when compared with other test groups. The data suggest that VQL could be a promising nanoscaled therapeutic agent to overcome multidrug resistance, and may have important clinical implications for the treatment of cancer. Keywords: vincristine, quinine, combination therapy, liposome, multidrug resistance reversal, P-glycoprotein&nbsp

To study the respiratory system injury in fur processing environment.Environmental fungal survey was conducted in the fur processing procedures. Investigation of respiratory symptoms and chest X-ray examination were also carried out in 138 fur processing workers and 40 control workers. At the same time, the serum antibodies to fungi were analyzed by ELISA.Fungal number(629-3,681 cfu/m3) in fur processing procedures was much higher than those in the control environment. Cladosporium and Alternaria were the leading strains of fungi in fur processing procedures. The rates of respiratory symptoms(cough, sputum, chest tightness, dyspnea, and fever) in fur processing workers were higher than those in the control workers. The rates of the symptoms in female workers were 37.9%, 28.4%, 10.5%, 22.1%, 4.2%, respectively. Abnormalities of chest X ray were found in 7 workers. The serum antibodies to Cladosporium and Alternaria(A450 nm 0.631, 0.724, respectively) in fur workers were significantly higher than those in the control workers(P0.05). The positive rates of the antibodies to Cladosporium and Alternaria(44.2%, 42.8%) were significantly higher than those in the control workers(P0.01).Cladosporium and Alternaria may be the pathogens of occupational respiratory diseases in fur processing workers.