A Ti3 C2 TX /Pt-Pd based amperometric biosensor for sensitive cancer biomarker detection.

The detection of cancer biomarkers is of great significance for the early screening of cancer. Detecting the content of sarcosine in blood or urine has been considered to provide a basis for the diagnosis of prostate cancer. However, it still lacks simple, high-precision and wide-ranging sarcosine detection methods. In this work, a Ti3 C2 TX /Pt-Pd nanocomposite with high stability and excellent electrochemical performance has been synthesized by a facile one-step alcohol reduction and then used on a glassy carbon electrode (GCE) with sarcosine oxidase (SOx ) to form a sarcosine biosensor (GCE/Ti3 C2 TX /Pt-Pd/SOx ). The prominent electrocatalytic activity and biocompatibility of Ti3 C2 TX /Pt-Pd enable the SOx to be highly active and sensitive to sarcosine. Under the optimized conditions, the prepared biosensor has a wide linear detection range to sarcosine from 1 to 1000 µM with a low limit of detection of 0.16 µM (S/N = 3) and a sensitivity of 84.1 µA/mM cm2 . Besides, the reliable response in serum samples shows its potential in the early diagnosis of prostate cancer. More importantly, the successful construction and application of the amperometric biosensor based on Ti3 C2 TX /Pt-Pd will provide a meaningful reference for detecting other cancer biomarkers.

XA pH-Responsive and Colitis-Targeted Nanoparticle Loaded with Shikonin for the Oral Treatment of Inflammatory Bowel Disease in Mice.

Epidemiology shows that more than 6.8 million people in the world are influenced by inflammatory bowel disease (IBD) each year. IBD is a refractory inflammatory disease, and the disease mainly affects the colon. Shikonin (SK) was originally extracted from traditional Chinese medicine "Zicao" (with an English name Lithospermum erythrorhizon) and found to inhibit inflammation, regulate immunity, and be involved in healing wounds. Herein, we used chitosan (CS), hyaluronic acid (HA), and pH-responsive polymer Eudragits S100 (ES100) to design SK-loaded ES100/HA/CS nanoparticles (SK@SAC) as an oral delivery system to treat the colitis mice. Particle size of SK@SAC was 190.3 nm and drug loading efficiency was 6.6%. SAC nanoparticles accumulated in RAW264.7 macrophages and exhibited colitis-targeted ability by increasing the local drug concentration as well as reducing nonspecific distribution after oral gavage. In TNBS-induced IBD mice, SK@SAC treatment had significant therapeutic effects, regulated of pro-inflammatory cytokines (TNF-α, IL-6, and IL-1ß) and anti-inflammatory cytokines (IL-10 and TGF-ß), and also inhibited COX-2 and iNOS activity. SK@SAC also increased tight junction protein ZO-1 and occludin to some extent. These promising results showed that this novel oral SK-loaded nanoparticle drug delivery system for targeted treatment provides a new strategy for the management of IBD.

Facile Preparation of Hydrophilic Mesoporous Metal-Organic Framework via Synergistic Etching and Surface Functionalization for Glycopeptides Analysis.

In view of the size and hydrophilicity of glycopeptides, materials having suitable channels (size-exclusion) and strong hydrophilic surface (hydrophilic interaction) are preferred to enrich the glycopeptides in biological samples. Metal-organic frameworks (MOFs) are good candidates. However, their smaller microporous channels and low chemical stability have limited the application. Herein, a facile strategy was established to construct hydrophilic mesoporous MOF via synergistic etching and surface functionalization by using phytic acid (PA). Besides, polyvinylpyrrolidone (PVP) was added during MOF synthesis to enhance the water stability of the MOF. Owing to the expanded hydrophilic mesoporous channels, the PA-modified Ce-MOF effectively and selectively captured 422 glycopeptides from 155 glycoproteins in tryptic digests of human serum (2 µL). The present work sheds light on the easy fabrication of hydrophilic mesoporous materials, and this established material holds unique advantages for glycopeptides analysis in biological samples.

Highly Efficient Separation of Methylated Peptides Utilizing Selective Complexation between Lysine and 18-Crown-6.

Protein methylation is one of the most common and important post-translational modifications, and it plays vital roles in epigenetic regulation, signal transduction, and chromatin metabolism. However, due to the diversity of methylation forms, slight difference between methylated sites and nonmodified ones, and ultralow abundance, it is extraordinarily challenging to capture and separate methylated peptides from biological samples. Here, we introduce a simple and highly efficient method to separate methylated and nonmethylated peptides using 18-crown-6 as a mobile phase additive in high-performance liquid chromatography. Selective complexation between lysine and 18-crown-6 remarkably increases the retention of the peptides on a C18 stationary phase, leading to an excellent baseline separation between the lysine methylated and nonmethylated peptides. A possible binding mechanism is verified by nuclear magnetic resonance titration, biolayer interferometry technology, and quantum chemistry calculation. Through establishment of a simple enrichment methodology, a good selectivity is achieved and four methylated peptides with greatly improved signal-to-noise (S/N) ratios are successfully separated from a complex peptide sample containing 10-fold bovine serum albumin tryptic digests. By selecting rLys N as an enzyme to digest histone, methylation information in the histone could be well identified based on our enrichment method. This study will open an avenue and provide a novel insight for selective enrichment of lysine methylated peptides in post-translational modification proteomics.

Safe and Efficacious Diphtheria Toxin-Based Treatment for Melanoma: Combination of a Light-On Gene-Expression System and Nanotechnology.

The controversy surrounding the use of diphtheria toxin (DT) as a therapeutic agent against tumor cells arises mainly from its unexpected harmfulness to healthy tissues. We encoded the cytotoxic fragment A of DT (DTA) as an objective gene in the Light-On gene-expression system to construct plasmids pGAVPO (pG) and pU5-DTA (pDTA). Meanwhile, a cRGD-modified ternary complex comprising plasmids, chitosan, and liposome (pG&pDTA@cRGD-CL) was prepared as a nanocarrier to ensure transfection efficiency. Benefiting from spatiotemporal control of this light-switchable transgene system and the superior tumor targeting of the carrier, toxins were designed to be expressed selectively in illuminated lesions. In vitro studies suggested that pG&pDTA@cRGD-CL exerted arrest of the S phase in B16F10 cells upon blue light irradiation and, ultimately, induced the apoptosis and necrosis of tumor cells. Such DTA-based treatment exerted enhanced antitumor activity in mice bearing B16F10 xenografts and displayed prolonged survival time with minimal side effects. Hence, we described novel DTA-based therapy combined with nanotechnology and the Light-On gene-expression system: such treatment could be a promising strategy against melanoma.

Targeted immobilization of titanium (IV) on magnetic mesoporous nanomaterials derived from metal-organic frameworks for high-efficiency phosphopeptide enrichment in biological samples.

A selectively modified porous metal/carbon nanocomposite was fabricated to enhance the enrichment of low-abundance phosphopeptides from biological samples. The carbon matrix derived from the metal-organic framework provides a suitable pore size to allow the diffusion of peptides, while the deliberately modified metal nanoparticles within the pores enhance their interaction with the phosphopeptides. This nanocomposite shows extremely high enrichment selectivity for phosphopeptides in the MALDI-TOF MS detection, even when the molar ratio of α-casein digests versus bovine serum albumin digests was up to about 1:20,000. By combining such nanocomposite with nano-LC-MS/MS, 4556 unique phosphopeptides were identified with high selectivity (95.2%) from HeLa cell extracts. Furthermore, phosphopeptides from prostate tissue digests were also determined. A total of 277 and 1242 phosphopeptides were identified from normal and tumor tissues of a patient with prostate cancer, respectively. This indicates that phosphorylation and prostate cancer can be related to each other.

A metal-free and preconcentration-free method for non-enzymatic amperometric determination of pentachlorophenol using a ZIF-derived hollow carbon material.

An enzyme-free, metal-free, and preconcentration-free electrochemical sensor for pentachlorophenol assay has been fabricated. The interface of the sensor is based on a hollow zeolitic imidazolate framework-derived mesoporous carbon material (denoted as HZC/SPCE). The sensor exhibits linear amperometric response upon pentachlorophenol at 0.82 V (vs. Ag/AgCl) in the concentration range 0.001 to 26.8 mg L-1 (3.75 × 10-8~1.006 × 10-4 M) (R2 = 0.997). The sensitivity of HZC/SPCE is 3.53 × 102 µA mM-1 cm-2 with a detection limit of 2.05 × 10-9 M (S/N = 3) for pentachlorophenol. The method has been applied to the determination of pentachlorophenol in spiked food packaging samples with recoveries in the range 92.0 to 107.0%. Graphical abstract Schematic representation of the synthesis of hollow ZIFs-derived hollow carbon material. Free protons derived from tannic acid penetrated into ZIF-8 to destroy its solid framework and the outer parts covered by tannic acid were protected from further etching. After pyrolysis, the morphology of HZC remained similar to that of HZIF-8. Abbreviation: CTAB: hexadecyl trimethyl ammonium bromide; Melm: 2-methylimidazole; ZIF-8: zeolitic imidazolate framework-8; TA: tannic acid; HZIF-8: hollow zeolitic imidazolate framework-8; HZC: hollow zeolitic imidazolate frameworks (ZIFs)-derived mesoporous carbon material.

Self-Amplified Photodynamic Therapy through the 1 O2 -Mediated Internalization of Photosensitizers from a Ppa-Bearing Block Copolymer.

Nanocarriers are employed to deliver photosensitizers for photodynamic therapy (PDT) through the enhanced penetration and retention effect, but disadvantages including the premature leakage and non-selective release of photosensitizers still exist. Herein, we report a 1 O2 -responsive block copolymer (POEGMA-b-P(MAA-co-VSPpaMA) to enhance PDT via the controllable release of photosensitizers. Once nanoparticles formed by the block copolymer have accumulated in a tumor and have been taken up by cancer cells, pyropheophorbide a (Ppa) could be controllably released by singlet oxygen (1 O2 ) generated by light irradiation, enhancing the photosensitization. This was demonstrated by confocal laser scanning microscopy and in vivo fluorescence imaging. The 1 O2 -responsiveness of POEGMA-b-P(MAA-co-VSPpaMA) block copolymer enabled the realization of self-amplified photodynamic therapy by the regulation of Ppa release using NIR illumination. This may provide a new insight into the design of precise PDT.

Hydrophilic Nanocomposite Functionalized by Carrageenan for the Specific Enrichment of Glycopeptides.

A hydrophilic nanocomposite was synthesized by an easy route to improve glycopeptides enrichment efficiency. This new composite, prepared with a method based on electrostatic interaction, was demonstrated to be efficient for immobilization of carrageenan on graphene oxide/poly(ethylenimine) support (denoted as GO-PEI-Carr). Carrageenan, which has a large number of hydroxyl groups and is fully negatively charged, is a new modified phase of hydrophilic materials in glycoproteomics. The introduction of carrageenan provided the composite not only a perfect surface charge but also a greater ability to enrich glycosylated peptides. Thirty-four glycopeptides from human serum immunoglobulin G (IgG) tryptic digests were obviously observed with greatly improved signal-to-noise (S/N) ratio. A good selectivity was still kept even when the molar ratio of IgG and bovine serum albumin (BSA) tryptic digest mixtures reached to 1:500. Meanwhile, 76 glycopeptides derived from 56 glycoproteins with 83 N-glycosylation sites were identified from human serum and 149 glycopeptides derived from 129 glycoproteins with 157 N-glycosylation sites were identified from mouse liver tissues, which showed the ability to enrich glycopeptides from complex biological samples. In addition, GO-PEI-Carr exhibited a unique repeatability and stability even after enrichment of glycopeptides for 20 times. It also performed a higher sensitivity (1 fmol/µL IgG), a better enrichment capacity (up to ∼300 mg/g), and an ideal enrichment recovery (90.8% and 109.5%) for glycopeptides enrichment, indicating a great potential for the application of glycoproteomic research.

Sensitization of Hypoxic Tumor to Photodynamic Therapy via Oxygen Self-Supply of Fluorinated Photosensitizers.

Photodynamic therapy (PDT) utilizes photosensitizers to convert innoxious oxygen to cytotoxic reactive oxygen species under an appropriate light, thus inducing cancer cells necrosis. However, PDT performs in an oxygen-dependent method to destroy cells while hypoxia is a feature for most solid tumors. To effectively improve the PDT effect against solid tumors, an oxygen self-supplying and pH-sensitive therapeutic nanoparticle (PTFC) has been developed by the self-assembly of a tetrakis(pentafluorophenyl) chlorin (TFPC)-conjugated block copolymer (POEGMA-b-P(DEAEMA-co-GMA)). PTFC nanoparticles can transport oxygen to a tumor site with their accumulation in the tumor on account of the good oxygen solubility, therefore relieving the oxygen deficiency of a solid tumor and enhancing the PDT efficacy. It is worth noting that the oxygen loading was realized by the fluorinated photosensitizer itself. In addition, the phototoxicity of PTFC nanoparticles is greatly improved in an acidic aqueous environment due to the DEAEMA unit protonation, which not only enhanced the cellular uptake of nanoparticles but also weakened the aggregation of photosensitizers. Taking the hypoxia and acidic microenvironment of solid tumors, PTFC nanoparticles could be efficiently taken up and disassembled to release oxygen upon accumulation at tumor sites, thus significantly improving the PDT efficacy against solid tumors.

Electrochemical detection of superoxide anions in HeLa cells by using two enzyme-free sensors prepared from ZIF-8-derived carbon nanomaterials.

Two kinds of carbon-based nanozymes were constructed from the same precursor of zeolitic imidazolate framework-8 (ZIF-8) for O2•- determination. Hollow carbon cubic nanomaterial (labelled as HCC) was obtained by chemically etching ZIF-8 with tannic acid and a subsequent calcination. A porous carbon cubic nanomaterial (labelled as PCC) was prepared by directly pyrolysis. Then HCC and PCC were immobilized on the surface of screen printed carbon electrodes (SPCE), fabricating HCC and PCC modified electrodes (denoted as HCC/SPCE and PCC/SPCE). HCC/SPCE, best operated at -0.5 V (vs. Ag/AgCl), has a sensitivity of 6.55 × 102 nA µM-1 cm-2 with a detection limit of 207 nM (at S/N = 3) for O2•- sensing. And PCC/SPCE, best operated at -0.4 V (vs. Ag/AgCl), exhibited a superior performance for O2•- detection with a sensitivity of 1.14 × 103 nA µM-1 cm-2 and a low detection limit of 140 nM (at S/N = 3). The two sensors possess excellent reproducibility and stability. They were used to sense O2•- released from HeLa cells. Graphical abstract Illustration of the synthesis of the hollow carbon cubic nanomaterial (HCC) and of the porous carbon cubic nanomaterial (PCC), and the scheme for detection of superoxide anions in HeLa cell.

Preparation of a hydrophilic interaction liquid chromatography material by sequential electrostatic deposition of layers of polyethyleneimine and hyaluronic acid for enrichment of glycopeptides.

A hydrophilic interaction liquid chromatography (HILIC) material with application in glycoproteomics was obtained by sequential deposition of polyethyleneimine (PEI) and hyaluronic acid (HA) on a negatively charged substrate by means of electrostatic self-assembly. This kind of surface modification endows the material with excellent hydrophilicity and warrants efficient glycopeptides enrichment. The feasibility of this enrichment was verified by using dendritic mesoporous silica nanoparticles (DMSNs) and magnetic graphene oxide (MagG) as negatively charged substrates for PEI and HA adhesion. The two final products (DMSNs@PEI@HA and MagG@PEI@HA) exhibit high enrichment selectivity (molar ratios of IgG and BSA digests = 1:500 and 1:1000), sensitivity (detection limit, 2 fmol/µL), recovery (>90%) and enrichment capacity (300 mg/g). When using DMSNs@PEI@HA, 419 N-glycopeptides derived from 105 glycoproteins were identified. When using MagG@PEI@HA, 376 N-glycopeptides derived from 102 glycoproteins were identified, both from a 2 µL serum sample. This is better than by methods described in previous reports. Graphical abstract Schematic representation of hydrophilic modification of negatively charged nanomaterial substrates by electrostatic self-assembly techniques to obtain hydrophilic interaction liquid chromatography (HILIC) materials for enrichment of N-glycopeptides.

Colorimetric evaluation of the hydroxyl radical scavenging ability of antioxidants using carbon-confined CoOx as a highly active peroxidase mimic.

The authors present a colorimetric method for the evaluation of the hydroxyl radical scavenging capability of antioxidants by exploiting carbon-confined mixed cobalt oxide nanoparticles (denoted as C-confined CoOx NPs) as a novel peroxidase mimic. The nanozyme can be prepared from the metal-organic framework ZIF-67 by calcination at a moderate temperature. It exhibits peroxidase-mimicking activity and catalyzes the oxidation of colorless 3,3',5,5'-tetramethylbenzidine (TMB) to form a blue product in the presence of H2O2 via generation of hydroxyl radicals. However, in the presence of an antioxidant, the color reaction is suppressed due to scavenging of hydroxyl radicals by the antioxidant. Based on this principle, the hydroxy radical scavenging ability of glutathione (GSH), cysteine (Cys), tannic acid (TA) and tea polyphenols (TP) was assessed. It was found that these antioxidants can scavenge hydroxyl radicals in the following decreasing order: TA>Cys>GSH>TP. The assay was also used to quantify the antioxidative power of common fruit extracts. Graphical abstract Schematic presentation for evaluating the hydroxyl radical scavenging ability of different antioxidants using carbon-confined mixed cobalt oxide nanoparticles (denoted as C-confined CoOx NPs) as a highly active peroxidase mimic. With excellent activity, the C-confined CoOx NPs together with the visible peroxidase reaction can be employed as a powerful tool to rapidly screen appropriate antioxidants from natural samples and measure their activity for guiding their usage in related products.

The Design and Synthesis of Fluorescent Coumarin Derivatives and Their Study for Cu2+ Sensing with an Application for Aqueous Soil Extracts.

A series of fluorescent coumarin derivatives 2a-e were systematically designed, synthesized and studied for their Cu2+ sensing performance in aqueous media. The sensitivities and selectivities of the on-to-off fluorescent Cu2+ sensing signal were in direct correlation with the relative arrangements of the heteroatoms within the coordinating moieties of these coumarins. Probes 2b and 2d exhibited Cu2+ concentration dependent and selective fluorescence quenching, with linear ranges of 0-80 µM and 0-10 µM, and limits of detection of 0.14 µM and 0.38 µM, respectively. Structural changes of 2b upon Cu2+ coordination were followed by fluorescence titration, attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), mass spectrometry, and single crystal X-ray diffraction on the isolated Cu2+-coumarin complex. The results revealed a 1:1 stoichiometry between 2b and Cu2+, and that the essential structural features for Cu2+-selective coordination are the coumarin C=O and a three-bond distance between the amide NH and heterocyclic N. Probe 2b was also used to determine copper (II) levels in aqueous soil extracts, with recovery rates over 80% when compared to the standard soil analysis method: inductively coupled plasma-mass spectrometry (ICP-MS).

Hydrophilic Phytic Acid-Coated Magnetic Graphene for Titanium(IV) Immobilization as a Novel Hydrophilic Interaction Liquid Chromatography-Immobilized Metal Affinity Chromatography Platform for Glyco- and Phosphopeptide Enrichment with Controllable Selectivity.

In this work, multifunctional Ti4+-immobilized phytic acid-modified magnetic graphene (denoted as MagG@PEI@PA-Ti4+) nanocomposites were fabricated through a facile route for simultaneous/respective enrichment of N-glyco- and phosphopeptides. Phytic acid (PA), with six phosphate groups, possesses excellent hydrophilicity and metal ion coordination ability, which endowed the MagG@PEI@PA-Ti4+ with combined properties of immobilized metal ion affinity chromatography (IMAC)- and hydrophilic interaction liquid chromatography (HILIC)-based materials. On the basis of the different binding ability of N-glyco- and phosphopeptides on MagG@PEI@PA-Ti4+, the MagG@PEI@PA-Ti4+ nanocomposites could enrich N-glyco- and phosphopeptides simultaneously or respectively by using different enrichment conditions, achieving controllable selective enrichment of N-glyco- and phosphopeptides. The proposed nanocomposites demonstrated an outstanding performance for selective enrichment of N-glycopeptides (selectivity, 1:1000 molar ratios of IgG/BSA; sensitivity, 0.5 fmol/µL IgG; loading capacity, 300 mg g-1; recovery, >90%) and phosphopeptides (selectivity, 1:5000 molar ratios of α-casein/BSA; sensitivity, 0.1 fmol/µL α-casein; loading capacity, 100 mg g-1; recovery, >90%). Taking advantage of these merits, a total of 393 N-glycopeptides derived from 259 glycoproteins and 574 phosphopeptides derived from 341 phosphoproteins were identified from 200 µg of HeLa cell extracts through a single-step enrichment using MagG@PEI@PA-Ti4+.

Dendritic Mesoporous Silica Nanoparticles with Abundant Ti4+ for Phosphopeptide Enrichment from Cancer Cells with 96% Specificity.

Selective enrichment and sensitive detection of phosphopeptides are of great significance in many bioapplications. In this work, dendritic mesoporous silica nanoparticles modified with polydopamine and chelated Ti4+ (denoted DMSNs@PDA-Ti4+) were developed to improve the enrichment selectivity of phosphopeptides. The unique central-radial pore structures endowed DMSNs@PDA-Ti4+ with a high surface area (362 m2 g-1), a large pore volume (1.37 cm3 g-1), and a high amount of chelated Ti4+ (75 µg mg-1). Compared with conventional mesoporous silica-based materials with the same functionalization (denoted mSiO2@PDA-Ti4+) and commercial TiO2, DMSNs@PDA-Ti4+ showed better selectivity and a lower detection limit (0.2 fmol/µL). Moreover, 2422 unique phosphopeptides were identified from HeLa cell extracts with a high specificity (>95%) enabled by DMSNs@PDA-Ti4+, better than those in previous reports.

pH-Sensitive DOX-Loaded PAA-PF127-PAA Micelles Combined with Cryotherapy for Treating Walker 256 Carcinosarcoma in a Rat Model.

In this work, a novel combination of drug therapy and cryotherapy for tumor treatment was developed. Pluronic F127 modified with poly(acrylic acid) at two terminals (denoted as PAA-PF127-PAA) was used as carriers for doxorubicin (DOX) delivery. Due to the pH-sensitive property endowed by PAA, the DOX-loaded PAA-PF127-PAA micelles released DOX faster in the slightly acidic physiological environment of the tumor site than that in the neutral physiological environment. Three-group rats bearing Walker 256 carcinosarcoma were respectively treated with cryotherapy, combination of DOX-loaded micelles and cryotherapy, and saline injection to investigate the effect of the combined therapy. The apoptosis rate of TdT-mediated dUTP nick-end labeling (TUNEL) slices indicated that compared with cryotherapy alone, the DOX-loaded PAA-PF127-PAA micelles combining with cryotherapy showed increased apoptosis. Thus, the combination of drug therapy and cryotherapy can be used as an effective technique for tumor treatment.

Synthesis and evaluation of a maltose-bonded silica gel stationary phase for hydrophilic interaction chromatography and its application in Ginkgo Biloba extract separation in two-dimensional systems.

Maltose covalently bonded to silica was prepared by using carbonyl diimidazole as a cross-linker and employed as a stationary phase for hydrophilic interaction liquid chromatography. The column efficiency and the effect of water content, buffer concentration, and pH value influenced on retention were investigated. The separation or enrichment selectivity was also studied with nucleosides, saccharides, amino acids, peptides, and glycopeptides. The results indicated that the stationary phase processed good separation efficiency and separation selectivity in hydrophilic interaction liquid chromatography mode. Moreover, a two-dimensional hydrophilic interaction liquid chromatography× reversed-phase liquid chromatography method with high orthogonality was developed to analyze the Ginkgo Biloba extract fractions. The development of this two-dimensional chromatographic system would be an effective tool for the separation of complex samples of different polarities and contents.

Synergistic anticancer effects of andrographolide and paclitaxel against A549 NSCLC cells.

CONTEXT: Paclitaxel (PTX) is widely used in chemotherapy for cancer treatment; however, it has some serious side effects. Andrographolide (Andro) is a potential cancer therapeutic agent isolated from Andrographis paniculata (Burm. f.) Nees (Acanthaceae). OBJECTIVE: The objective of this study is to evaluate the effects of PTX combined with Andro against A549 cells. MATERIALS AND METHODS: The effects of 24-48 h treatment with 0.48-60.75 nM PTX and 5.10-328.0 µM Andro on cellular proliferation, apoptosis, cell cycle and intracellular reactive oxygen species (ROS) were determined by sulphorhodamine B assay, Annexin V-FITC/PI apoptosis detection, PI staining and ROS assay, respectively. Synergy was determined using combination index. The antitumour efficacy of 20 mg/kg PTX with 100 mg/kg Andro was studied in a xenograft murine model. RESULTS: IC50 value of the PTX combined with Andro against A549 cells was 0.5-7.4 nM, which was significantly lower than that of PTX (15.9 nM). PTX with 10 µM Andro caused (1.22-1.27)-fold apoptosis and 1.7-fold ROS accumulation compared with PTX alone. N-Acetylcysteine, a ROS scavenger, blocked this synergy in vitro. In contrast, G2/M phase cell cycle arrest resulting from PTX was not potentiated by Andro. Moreover, PTX in combination with Andro inhibited the growth of A549 transplanted tumours by 98%. DISCUSSION AND CONCLUSION: The results indicate that the combination of PTX and Andro exert significant synergistic anticancer effect on A549 cells in vitro and in vivo. The synergy may be the result of the accumulation of ROS. The combination of Andro and PTX represents a potential strategy for the treatment of A549 cells.

Doxorubicin-Loaded Micelles Based on Folic Acid Conjugated pH-Dependent Thermo-Sensitive Copolymer: In Vitro and In Vivo Evaluation.

In this paper, the doxorubicin (DOX)-loaded micelles were prepared based on a novel folic acid conjugated pH-dependent thermo-sensitive copolymer poly(D,L-lactic acid)-b-poly(N-isopropyl methacrylamide-co-N-isopropylmaelic acid-co-10-undecenoic acid) (PLA-PNNUA-FA) constructed to provide an active targeting drug delivery and triggered drug release system. The micelles were able to target tumors through the interaction between folic acid and its receptors which are overexpressed on the tumor cell membrane, and achieved pH-dependent thermo induced drug release in the intracellular mild acidic media such as endosomes and lysosomes after the micelles enter the cells. The results of cell assays and animal experiments showed that the micelles exhibited obvious tumor penetration efficiency in vivo, also improved DOX cell uptake and cytotoxicity in vitro. It was suggested that copolymer PLA-PNNUA-FA might be a potential targeted drug carrier to deliver chemotherapeutic drugs achieving better efficacy of chemotherapy.