Cytotoxicity of doxorubicin bound to poly(butyl cyanoacrylate) nanoparticles in rat glioma cell lines using different assays

The cytotoxicity of doxorubicin bound to poly(butyl cyanoacrylate) nanoparticles (Dox-PBCA-NP) was investigated in the rat glioma cell lines GS-9L, F-98 and RG-2. MTT and LDH assays were used as cytotoxic assays. In general, the cytotoxicity of nanoparticle-bound doxorubicin (Dox) was enhanced compared to the free drug in solution. However, responses of the cell lines towards the drug effects were different. In the case of free Dox in solution, this difference correlated with different intracellular concentrations of Dox, which in turn, depended on the level of P-glycoprotein (P-gp) expression in these cell lines. Accordingly, the 9L gliosarcoma (GS-9L) cells, which appeared to be most resistant towards Dox, were characterized by the highest P-gp expression.Additionally, the influence of surfactants on the cytotoxic effect was investigated at different Dox concentrations. It was shown that the presence of polysorbate 80 (Tween 80) in the nanoparticle formulation significantly enhanced the cytotoxicity, whereas poloxamer 188 (Pluronic F68) and poloxamine 908 (Tetronic 908) had a negligible influence.     

Ability of Doxorubicin-Loaded Nanoparticles to Overcome Multidrug Resistance of Tumor Cells After Their Capture by Macrophages

Purpose. Investigation of the ability of doxorubicin-loaded nanoparticles (NP/Dox) to overcome multidrug resistance (MDR) when they have first been taken up by macrophages. Methods. The growth inhibition of P388 sensitive (P388) and resistant (P388/ADR) tumor cells was evaluated in a coculture system consisting of wells with two compartments. The tumor cells were seeded into the lower compartment, the macrophages were introduced into the upper part in which the drug preparations were also added. Results. Doxorubicin exerted lower cytotoxicity on tumor cells in coculture compared with direct contact. In P388/ADR, NP/Dox cytotoxicity was far higher than that of free doxorubicin (Dox). Three different formulations of cyclosporin A (either free (CyA), loaded to nanoparticles (NP/CyA) or in a combined formulation with doxorubicin (NP/Dox-CyA)), were added to modulate doxorubicin efficacy. The addition of cyclosporin A to Dox increased drug cytotoxicity. Both CyA added to NP/Dox and NP/Dox-CyA were able to bypass drug resistance. Conclusions. Despite the barrier role of macrophages, NP/Dox remained far more cytotoxic than Dox against P388/ADR. Both NP/ Dox + CyA and NP/Dox-CyA allowed to overcome MDR, but the last one should present greater advantagein vivo by confining both drugs in the same compartment, hence reducing the adverse effects.     

Can marine‐derived fungus Neosartorya siamensis KUFA 0017 extract and its secondary metabolites enhance antitumor activity of doxorubicin? An in vitro survey unveils interactions against lung cancer cells

Doxorubicin (Dox) is one of the most successful anticancer drugs in use. However, chemoresistance is one of the main limitations that patients face. Therefore, development of new strategies to improve the efficacy of Dox is needed. Marine‐derived fungi are especially promising sources of new anticancer compounds. In this work, antitumor activity of crude ethyl extract of the cultures of the marine‐derived fungus Neosartorya siamensis KUFA 0017 (NS), combined with Dox, was evaluated in six cancer cell lines. To evaluate possible mechanisms involved in the eventual improvement of Dox's cytotoxicity by NS extract, effects on DNA damage, cell death, ultrastructural modifications, and intracellular accumulation of Dox were assessed. The NS extract demonstrated a significant enhancement of Dox's cytotoxic activity in A549 cells, inducing DNA damage, cell death, and intracellular accumulation of Dox. Additionally, the cytotoxic effect of eight compounds, isolated from this extract, that is, 2,4‐dihydroxy‐3‐methylacetophenone‐(C1), nortryptoquivaline‐(C2), chevalone C‐(C3), tryptoquivaline H‐(C4), fiscalin A‐(C5), epi‐fiscalin‐C (C6), epi‐neofiscalin A‐(C7), and epi‐fiscalin A‐(C8), alone and combined with Dox was also evaluated in lung cancer cells. The cytotoxic effect of Dox was potentiated by all the isolated compounds (except C1) in A549 cells. Therefore, we concluded that NS extract potentiated cytotoxicity by inhibiting cell proliferation, increasing intracellular accumulation of Dox, and inducing cell death (possibly by an autophagic process). The isolated compounds also enhanced the activity of Dox, supporting the potential of this sort of combination. These data call for further studies to characterize drug interactions and underlying mechanisms.     

Solid Lipid Nanoparticles for Potential Doxorubicin Delivery in Glioblastoma Treatment: Preliminary In Vitro Studies

The major obstacle to glioblastoma pharmacological therapy is the overcoming of the blood–brain barrier (BBB). In literature, several strategies have been proposed to overcome the BBB: in this experimental work, solid lipid nanoparticles (SLN), prepared according to fatty acid coacervation technique, are proposed as the vehicle for doxorubicin (Dox), to enhance its permeation through an artificial model of BBB. The in vitro cytotoxicity of Dox-loaded SLN has been measured on three different commercial and patient-derived glioma cell lines. Dox was entrapped within SLN thanks to hydrophobic ion pairing with negatively charged surfactants, used as counterions. Results indicate that Dox entrapped in SLN maintains its cytotoxic activity toward glioma cell lines; moreover, its permeation through hCMEC/D3 cell monolayer, assumed as a model of the BBB, was increased when the drug was entrapped in SLN. In conclusion, SLN proved to be a promising vehicle for the delivery of Dox to the brain in glioblastoma treatment.     

Prostate cancer-specific monoclonal antibody 5D4 significantly enhances the cytotoxicity of doxorubicin-loaded liposomes against target cells in vitro

Long-circulating liposomes loaded with doxorubicin (Dox) were additionally modified with the prostate cell-specific monoclonal antibody 5D4 (mAb 5D4). The resultant Dox-loaded 5D4-immunoliposomes specifically recognized prostate cancer cell lines of several different types expressing the mAb 5D4 antigen, PSMA, and significantly enhanced cytotoxicity toward these cells compared with the non-targeted Dox-liposomes in vitro while no increased toxicity was observed toward non-prostate (lung) cancer cell line.     

An in vitro demonstration of overcoming drug resistance in SKOV3 TR and MCF7 ADR with targeted delivery of polymer pro-drug conjugates

Drug resistance is a common phenomenon that occurs in cancer chemotherapy. Delivery of chemotherapeutic agents as polymer pro-drug conjugates (PPDCs) pretargeted with bispecific antibodies could circumvent drug resistance in cancer cells. To demonstrate this approach to overcome drug resistance, Paclitaxel (Ptxl)-resistant SKOV3 TR human ovarian- and doxorubicin (Dox)-resistant MCF7 ADR human mammary-carcinoma cell lines were used. Pre-targeting over-expressed biotin or HER2/neu receptors on cancer cells was conducted by biotinylated anti-DTPA or anti-HER2/neu affibody – anti-DTPA Fab bispecific antibody complexes. The targeting PPDCs are either D-Dox-PGA or D-Ptxl-PGA. Cytotoxicity studies demonstrate that the pretargeted approach increases cytotoxicity of Ptxl or Dox in SKOV3 TR or MCF7 ADR resistant cell lines by 5.4 and 27 times, respectively. Epifluorescent microscopy – used to track internalization of D-Dox-PGA and Dox in MCF7 ADR cells – shows that the pretargeted delivery of D-Dox-PGA resulted in a 2- to 4-fold increase in intracellular Dox concentration relative to treatment with free Dox. The mechanism of internalization of PPDCs is consistent with endocytosis. Enhanced drug delivery and intracellular retention following pretargeted delivery of PPDCs resulted in greater tumor cell toxicity in the current in vitro studies.     

Heat Enhanced Follicular Delivery of Isotretinoin to the Skin

Purpose

Fibrin gels (FBGs) are potential delivery vehicles for many drugs, and can be easily prepared from purified components. We previously demonstrated their applicability for the release of different doxorubicin (Dox) nanoparticles used clinically or in an experimental stage, such as its inclusion complex with the amino β-cyclodextrin polymer (oCD-NH₂/Dox). Here we extend these studies by in vitro and in vivo evaluations.

Methods

An in vitro cytotoxicity model consisting of an overlay of a neuroblastoma (NB) cell-containing agar layer above a drug-loaded FBG layer was used. Local toxicity in vivo (histology and blood analysis) was studied in a mouse orthotopic NB model (SHSY5YLuc⁺ cells implanted into the left adrenal gland).

Results

In vitro data show that FBGs loaded with oCD-NH₂/Dox have a slightly lower cytotoxicity against NB cell lines than those loaded with Dox. Fibrinogen (FG), and Ca²⁺ concentrations may modify this activity. In vivo data support a lower general and local toxicity for FBGs loaded with oCD-NH₂/Dox than those loaded with Dox.

Conclusion

Our results suggest a possible increase of the therapeutic index of Dox when locally administered through FBGs loaded with oCD-NH₂/Dox, opening the possibility of using these releasing systems for the treatment of neuroblastoma.

     

A novel valproic acid prodrug as an anticancer agent that enhances doxorubicin anticancer activity and protects normal cells against its toxicity in vitro and in vivo

The poor survival of patients with malignant gliomas, underscores the need to develop effective treatment modalities for this devastating disease. Epigenetic agents used in combination with chemotherapy provide a promising approach to evoke synergistic cytotoxicity in glioblastomas. Previously we have described the cytotoxic synergy between a butyric acid prodrug and radiation in glioblastoma cell lines and the potentiation of radiation efficacy in glioma xenografts. Herein, we describe and compare the activities of AN446 (valproyl ester-valpramide of acyclovir) a novel histone deacetylase inhibitor (HDACI) to the previously described AN7 a HDACI prodrug of butyric acid. In various cancer cell lines, AN446 was a ∼2–5-fold more potent anticancer agent HDACI than AN7. While AN446 augmented the anticancer efficacy of doxorubicin (Dox) it also reduced the Dox toxicity in non-cancerous cells. The interaction between AN446 and Dox in U251 and in 4T1 cell lines was synergistic in inducing cytotoxicity. We examined the concomitant physical and molecular changes in the tumor and heart of glioblastoma xenografts treated with AN446, AN7, Dox and the combination of the prodrugs with Dox. A weekly dose of 4 mg/kg Dox, caused toxicity in mice whereas AN446 (25 mg/kg) or AN7 (50 mg/kg) administered thrice weekly, did not. When Dox was administered with AN446 or AN7, the prodrugs ameliorated the decline in body weight, prolonged the time to failure and increased anticancer efficacy. Thus, the combination of Dox with AN446 or AN7 could add safety and efficacy to future treatment protocols for treating glioblastoma and other cancers.     

A New Polymer–Lipid Hybrid Nanoparticle System Increases Cytotoxicity of Doxorubicin Against Multidrug-Resistant Human Breast Cancer Cells

Purpose This work is intended to develop and evaluate a new polymer–lipid hybrid nanoparticle system that can efficiently load and release water-soluble anticancer drug doxorubicin hydrochloride (Dox) and enhance Dox toxicity against multidrug-resistant (MDR) cancer cells. Methods Cationic Dox was complexed with a new soybean-oil-based anionic polymer and dispersed together with a lipid in water to form Dox-loaded solid lipid nanoparticles (Dox–SLNs). Drug loading and release properties were measured spectrophotometrically. The in vitro cytotoxicity of Dox–SLN and the excipients in an MDR human breast cancer cell line (MDA435/LCC6/MDR1) and its wild-type line were evaluated by trypan blue exclusion and clonogenic assays. Cellular uptake and retention of Dox were determined with a microplate fluorometer. Results Dox–SLNs were prepared with a drug encapsulation efficiency of 60–80% and a particle size range of 80–350 nm. About 50% of the loaded drug was released in the first few hours and an additional 10–20% in 2 weeks. Treatment of the MDR cells with Dox–SLN resulted in over 8-fold increase in cell kill when compared to Dox solution treatment at equivalent doses. The blank SLN and the excipients exhibited little cytotoxicity. The biological activity of the released Dox remained unchanged from fresh, free Dox. Cellular Dox uptake and retention by the MDR cells were both significantly enhanced (p < 0.05) when Dox was delivered in Dox–SLN form. Conclusions The new polymer–lipid hybrid nanoparticle system is effective for delivery of Dox and enhances its efficacy against MDR breast cancer cells.     

Inhibition of P-Glycoprotein by D-α-Tocopheryl Polyethylene Glycol 1000 Succinate (TPGS)

Purpose. To investigate whether d--tocopheryl polyethylene glycol 1000 succinate (TPGS) functions as an inhibitor of P-glycoprotein (P-gp), the multidrug resistance transporter. Methods. Two assays were used to measure the function of TPGS on P-gp function. First, we examined the ability of TPGS to modulate the cytotoxicity of established, cytotoxic, P-glycoprotein substrates. Parental NIH 3T3 cells and NIH 3T3 cells transfected with the human MDR1 cDNA (G185) were exposed to doxorubicin, paclitaxel, colchicine, vinblastine and 5-fluorouracil (5FU) in the presence or absence of TPGS. Cytotoxicity was assessed with the MTT assay. Second, polarized transport of the P-gp substrates rhodamine 123 (R123), paclitaxel and vinblastine was measured using the human intestinal HCT-8 and Caco-2 cell lines grown in Transwell dishes. Drug flux was measured by liquid scintillation counting or fluorescence spectroscopy of the media. Results. G185 cells were 27–135 fold more resistant to the cytotoxic drugs doxorubicin, vinblastine, colchicine and paclitaxel than the parental NIH 3T3 cells. In contrast 5FU, which is not a P-gp substrate, is equally cytotoxic to parental and G185 cells. Co-administration of TPGS enhanced the cytotoxicity of doxorubicin, vinblastine, paclitaxel, and colchicine in the G185 cells to levels comparable to the parental cells. TPGS did not increase the cytotoxicity of 5FU in the G185 cells. Using a polarized epithelial cell transport assay, TPGS blocked P-gp mediated transport of Rl 23 and paclitaxel in a dose responsive manner. Conclusions. These data demonstrate that TPGS acts as a reversal agent for P-glycoprotein mediated multidrug resistance and inhibits P-gp mediated drug transport. These results suggest that enhanced oral bioavailability of drugs co-administered with TPGS may, in part, be due to inhibition of P-glycoprotein in the intestine.     

Fundamental Relationships Between the Composition of Pluronic Block Copolymers and Their Hypersensitization Effect in MDR Cancer Cells

Purpose. Previous studies have demonstrated that Pluronic block copolymers hypersensitize multiple drug resistant (MDR) cancer cells, drastically increasing the cytotoxic effects of anthracyclines and other anticancer cytotoxics in these cells. This work evaluates the dose dependent effects of these polymers on (i) doxorubicin (Dox) cytotoxicity and (ii) cellular accumulation of P-glycoprotein probe, rhodamine 123 (R123) in MDR cancer cells. Methods. Dox cytotoxicity and R123 accumulation studies are performed on monolayers of drug-sensitive (KB, MCF-7, Aux-Bl) and MDR (KBv, MCF-7/ADR, CH^rC5) cells. Results. Both tests reveal strong effects of Pluronic copolymers observed at concentrations below the critical micelle concentration (CMC) and suggest that these effects are due to the copolymer single chains ('unimers'). Using block copolymers with various lengths of hydrophobic propylene oxide (PO) and hydrophilic ethylene oxide (EO) segments these studies suggest that the potency of Pluronic unimers in MDR cells increases with elevation of the hydrophobicity of their molecule. Optimization of Pluronic composition in R123 accumulation and Dox cytotoxicity studies reveals that Pluronic copolymers with intermediate lengths of PO chains and relatively short EO segments have the highest net efficacy in MDR cells. Conclusions. The relationship between the structure of Pluronic block copolymers and their biological response modifying effects in MDR cells is useful for determining formulations with maximal efficacy with respect to MDR tumors.     

Ultrasound-Induced Hyperthermia Increases Cellular Uptake and Cytotoxicity of P-Glycoprotein Substrates in Multi-Drug Resistant Cells

Purpose. Localized hyperthermia has been shown previously to augment the cytotoxicity of some lipophilic anticancer drugs. Because many of the substrates for the multi-drug resistance (MDR) transporter P-glycoprotein (P-gp) are lipophilic in nature, studies were conducted to test the hypothesis that hyperthermia induced by ultrasound could also increase cellular uptake and cytotoxicity of P-gp substrates by P-gp-expressing cells. Methods. To test this hypothesis, we studied the effects of hyperthermia and ultrasound on cellular accumulation of putative P-gp substrates, rhodamine 123 (R123) and doxorubicin (DOX), and cytotoxicity of DOX in the parent and MDR variants of two human cancer cell lines. Results. Treatment of cells with hyperthermia or ultrasound (20 min at 41°C) both caused a significant increase over controls (no ultrasound treatment) in R123 and DOX accumulation in the parent and MDR lines of MV522 and KB cells. Ultrasound also substantially increased the antiproliferative effects of DOX in both the parent and MDR variants of MV522 and KB cell lines when compared with controls. Our results also indicated that ultrasound exerted a much greater effect on cellular accumulation of R123 and DOX and cytotoxicity enhancement of DOX in the MDR variants than putative P-gp antagonist such as verapamil. Conclusion. The present results point to the potential use of ultrasound-induced hyperthermia as a much safer alternative to P-gp antagonist for reversal of MDR.     

Cytotoxicity of neolignans identified in Saururus chinensis towards human cancer cell lines

The cytotoxicity of compounds derived from the aerial parts of Saururus chinensis towards 24 cancer model and six normal cell lines was examined by MTT assay and compared with those of the anticancer agents cisplatin and doxorubicin. The active principles were characterized as the neolignans manassantin A, and its erythro, erythro- and threo, erythro-epimers by spectroscopic analysis. Manassantin A was isolated from S. chinensis as a new cytotoxic principle. Its two epimers were isolated for the first time in nature. The neolignans were more active than cisplatin and doxorubicin, with IC50 values of the neolignans, cisplatin, and doxorubicin against SK-Hep-1, PC-3, DU-145, BT-20, SK-BR-3, T-47D, Hela, T98G, and SK-MEL-28 cancer cell lines, in the ranges 0.018-0.423, 1.175-7.922, and 0.131- >50 microg/mL, respectively. Manassantin A and its threo, erythro-epimer were equicytotoxic towards model cancer cell lines. threo, erythro-Manassantin A was more active than erythro, erythro-manassantin A. Additionally, these three neolignans (IC50 > 10 microg/mL) had very low cytotoxicity towards six normal cell lines, whereas cisplatin (IC50 2.846-0.825 microg/mL) and doxorubicin (IC50 5.222-0.008 microg/mL) exhibited potent cytotoxic effects. Structure-activity relationships indicate that the hydroxy moiety appears to be essential for cytotoxicity. These neolignans merit further study as potential anticancer agents or as leads.     

Cross-talk between phosphatidic acid and ceramide during ethanol-induced apoptosis in astrocytes

Background

Anticancer bisdioxopiperazines, including ICRF-154, razoxane (Raz, ICRF-159) and ICRF-193, are a family of anticancer agents developed in the UK, especially targeting metastases of neoplasms. Two other bisdioxopiperazine derivatives, probimane (Pro) and MST-16, were synthesized at the Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China. Cytotoxic activities and mechanisms of Raz (+)-steroisomer (ICRF-187, dexrazoxane), Pro and MST-16 against tumor cells were evaluated by MTT colorimetry, flow cytometry and karyotyping.

Results

Pro was cytotoxic to human tumor cell lines in vitro (IC₅₀<50 μM for 48 h). Four human tumor cell lines (SCG-7901, K562, A549 and HL60) were susceptible to Pro at low inhibitory concentrations (IC₅₀ values < 10 μM for 48 h). Although the IC₅₀ against HeLa cell line of vincristine (VCR, 4.56 μM), doxorubicin (Dox, 1.12 μM) and 5-fluoruouracil (5-Fu, 0.232 μM) are lower than Pro (5.12 μM), ICRF-187 (129 μM) and MST-16 (26.4 μM), VCR, Dox and 5-Fu shows a low dose-related – high cytotoxic activity. Time-response studies showed that the cytotoxic effects of Pro are increased for 3 days in human tumor cells, whereas VCR, Dox and 5-Fu showed decreased cytotoxic action after 24 h. Cell cycle G₂/M phase arrest and chromosome segregation blocking by Pro and MST-16 were noted. Although there was similar effects of Pro and MST-16 on chromosome segregation blocking action and cell cycle G₂/M phase arrest at 1- 4 μM, cytotoxicity of Pro against tumor cells was higher than that of MST-16 in vitro by a factor of 3- 10 folds. Our data show that Pro may be more effective against lung cancer and leukemia while ICRF-187 and MST-16 shows similar IC₅₀ values only against leukemia.

Conclusion

It suggests that Pro has a wider spectrum of cytotoxic effects against human tumor cells than other bisdioxopiperazines, especially against solid tumors, and with a single cytotoxic pathway of Pro and MST-16 affecting chromosome segregation and leading also to cell G₂/ M phase arrests, which finally reduces cell division rates. Pro may be more potent than MST-16 in cytotoxicity. High dose- and time- responses of Pro, when compared with VCR, 5-Fu and Dox, were seen that suggest a selectivity of Pro against tumor growth. Compounds of bisdioxopiperazines family may keep up their cytotoxic effects longer than many other anticancer drugs.     

Improved cytotoxicity and preserved level of cell death induced in colon cancer cells by doxorubicin after its conjugation with iron-oxide magnetic nanoparticles

A promising strategy for overcoming the problem of limited efficacy in antitumor drug delivery and in drug release is the use of a nanoparticle-conjugated drug. Doxorubicin (Dox) anticancer chemotherapeutics has been widely studied in this respect, because of severe cardiotoxic side effects. Here, we investigated the cytotoxic effects, the uptake process, the changes in cell cycle progression and the cell death processes in the presence of iron-oxide magnetic nanoparticles (Nps) and doxorubicin conjugates (Dox-Nps) in human colon HT29 cells. The amount of Dox participated in biological action of Dox-Nps was determined by cyclic voltammetry and thermogravimetric measurements. The cytotoxicity of Dox-Nps was shown to be two/three times higher than free Dox, whereas Nps alone did not inhibit cell proliferation. Dox-Nps penetrated cancer cells with higher efficacy than free Dox, what could be a consequence of Dox-Nps aggregation with proteins in culture medium and/or with cell surface. The treatment of HT29 cells with Dox-Nps and Dox at IC₅₀ concentration resulted in G2/M arrest followed by late apoptosis and necrosis. Summing up, the application of iron-oxide magnetic nanoparticles improved Dox-Nps cell penetration compared to free Dox and achieved the cellular response to Dox-Nps conjugates similar to that of Dox alone.     

Anticancer Drug Delivery with Transferrin Targeted Polymeric Chitosan Vesicles

Purpose. The study reports the initial biological evaluation of targeted polymeric glycol chitosan vesicles as carrier systems for doxorubicin (Dox). Methods. Transferrin (Tf) was covalently bound to the Dox-loaded palmitoylated glycol chitosan (GCP) vesicles using dimethylsuber- imidate (DMSI). For comparison, glucose targeted niosomes were prepared using N-palmitoyl glucosamine. Biological properties were studied using confocal microscopy, flow cytometry, and cytotoxicity assays as well as a mouse xenograft model. Results. Tf vesicles were taken up rapidly with a plateau after 1-2 h and Dox reached the nucleus after 60-90 min. Uptake was not increased with the use of glucose ligands, but higher uptake and increased cytotoxicity were observed for Tf targeted as compared to GCP Dox alone. In the drug-resistant A2780AD cells and in A431 cells, the relative increase in activity was significantly higher for the Tf-GCP vesicles than would have been expected from the uptake studies. All vesicle formulations had a superior in vivo safety profile compared to the free drug. Conclusions. The in vitro advantage of targeted Tf vesicles did not translate into a therapeutic advantage in vivo. All vesicles reduced tumor size on day 2 but were overall less active than the free drug.     

EGF-modified mPEG-PLGA-PLL nanoparticle for delivering doxorubicin combined with Bcl-2 siRNA as a potential treatment strategy for lung cancer

Context: Nanoparticles (NPs) have been widely used as carriers to deliver siRNA and chemotherapeutic agents. Bcl-2 siRNA has been widely used to induce cancer cell apoptosis, and doxorubicin (Dox) can destroy cancer cells by binding with cancer cell DNA.

Objective: To investigate the therapeutic effect on lung cancer of simultaneously delivering Dox and Bcl-2-siRNA using epidermal growth factor (EGF) modified monomethoxy (polyethylene glycol)-poly (D, L-lactide-co-glycolide)-poly(L-lysine) (mPEG-PLGA-PLL, PEAL) NPs (EGF-PEAL).

Methods: EGF-PEAL NPs were characterized with respect to size, zeta potential and morphology. Cytotoxicity and drug (or siRNA) loading capacity of EGF-PEAL NPs were analyzed. Cellular uptake, drug release profile, cell killing effects of Dox and Bcl-2-siRNA-loaded EGF-PEAL NPs were assessed. Biodistribution and therapeutic effects of Dox and Bcl-2-siRNA EGF-PEAL NPs were evaluated in H1299 tumor-bearing mice.

Results and discussion: EGF-PEAL NPs or PEAL NPs had nearly negligible cytotoxicity toward H1299 cells. Dox and Bcl-2-siRNA gradually released from EGF-PEAL NPs and exhibited sustained release patterns. Dox and Bcl-2-siRNA-loaded NPs were taken up by cells and induced the apoptosis of H1299 cells more effectively than using Dox or Bcl-2 siRNA alone. With the intravenous injection of PEAL NPs into H1299 xenografted mice, we found that combination treatment suppressed lung cancer growth and reduced Bcl-2 expression in tumor tissue, and EGF-PEAL NPs concentrated in lung tumor much more than non-targeted PEAL NPs.

Conclusion: We conclude that co-delivery of Dox and Bcl-2-siRNA by tumor-targeted EGF-PEAL NPs could significantly inhibit lung cancer growth.     

Cytotoxic activity of physodic acid and acetone extract from Hypogymnia physodes against breast cancer cell lines

Context: Lichens produce specific secondary metabolites with different biological activity.

Objective: This study investigated the cytotoxic effects of physodic acid, in addition to the total phenolic content and cytotoxic and antioxidant activity of acetone extract from Hypogymnia physodes (L.) Nyl. (Parmeliaceae).

Materials and methods: Cytotoxicity of physodic acid (0.1–100?μM) was assessed in MDA-MB-231, MCF-7 and T-47D breast cancer cell lines and a nontumorigenic MCF-10A cell line using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, neutral red uptake and crystal violet assays during 72?h of incubation. An MTT assay was also used to assess the cytotoxic effects of the acetone extract (0.1–100?μg/mL) in the MDA-MB-231, MCF-7, T-47D breast cancer cell lines after 72?h. The total phenolic content of the acetone extract, expressed as the gallic acid equivalent, was investigated using Folin-Ciocalteu reagent. The antioxidant activity of the extract was assessed by 2,2-diphenyl-1-picrylhydrazyl and ferric-reducing antioxidant power assays.

Results: The cytotoxic activity of physodic acid appeared to be strong in the tumorigenic cell lines (IC₅₀ 46.0–93.9?μM). The compound was inactive against the nontumorigenic MCF-10A cell line (IC_50?>100?μM). The acetone extract showed cytotoxicity in the breast cancer cell lines (IC₅₀ 46.2–110.4?μg/mL). The acetone extract was characterized by a high content of polyphenols, and it had significant antioxidant activity.

Discussion and conclusion: Physodic acid and acetone extract from H. physodes displayed cytotoxic effects in the breast cancer cell lines. Furthermore, acetone extract from H. physodes possessed significant antioxidant properties.     

The 4′-O-benzylated doxorubicin analog WP744 overcomes resistance mediated by P-glycoprotein,multidrug resistance protein and breast cancer resistance protein in cell lines and acute myeloid leukemia cells

Summary Background: The synthetic 4’-O-benzylated doxorubicin analog WP744 was designed to abrogate transport by the multidrug resistance (MDR)-associated ATP-binding cassette (ABC) proteins P-glycoprotein (Pgp) and multidrug resistance protein (MRP-1). We compared its uptake and cytotoxicity with those of doxorubicin and daunorubicin in cell lines overexpressing Pgp, MRP-1 or breast cancer resistance protein (BCRP) and in acute myeloid leukemia (AML) cells. Methods: Cellular uptake was studied by flow cytometry and cytotoxicity in 96-h 96-well cultures in cell lines overexpressing Pgp, MRP-1 or wild type (BCRP^R482) or mutant (BCRP^R482T, BCRP^R482G) BCRP and in pre-treatment AML marrow cells. Results: Uptake and cytotoxicity of WP744 were consistently greater than those of doxorubicin and daunorubicin at equimolar concentrations in all cell lines studied and in AML cells. Conclusion: WP744 overcomes transport by Pgp, MRP-1 and BCRP in cell lines and AML cells and is a promising agent for clinical development in AML and other malignancies with broad-spectrum multidrug resistance.     

Bicontinuous Cubic Liquid Crystalline Nanoparticles for Oral Delivery of Doxorubicin: Implications on Bioavailability,Therapeutic Efficacy,and Cardiotoxicity

Purpose

The present study explores the potential of bicontinous cubic liquid crystalline nanoparticles (LCNPs) for improving therapeutic potential of doxorubicin.

Methods

Phytantriol based Dox-LCNPs were prepared using hydrotrope method, optimized for various formulation components, process variables and lyophilized. Structural elucidation of the reconstituted formulation was performed using HR-TEM and SAXS analysis. The developed formulation was subjected to exhaustive cell culture experiments for delivery potential (Caco-2 cells) and efficacy (MCF-7 cells). Finally, in vivo pharmacokinetics, pharmacodynamic studies in DMBA induced breast cancer model and cardiotoxicity were also evaluated.

Results

The reconstituted formulation exhibited Pn3m type cubic structure, evident by SAXS and posed stability in simulated gastrointestinal fluids and at accelerated stability conditions for 6 months. Dox-LCNPs revealed significantly higher cell cytotoxicity (16.23-fold) against MCF-7 cell lines as compared to free drug owing to its preferential localization in the vicinity of nucleus. Furthermore, Caco-2 cell experiments revealed formation of reversible “virtual pathways” in the cell membrane for Dox-LCNPs and hence posed significantly higher relative oral bioavailability (17.74-fold). Subsequently, Single dose of Dox-LCNPs (per oral) led to significant reduction in % tumor burden (~42%) as compared that of ~31% observed in case of Adriamycin® (i.v.) when evaluated in DMBA induced breast cancer model. Moreover, Dox induced cardiotoxicity was also found to be significantly lower in case of Dox-LCNPs as compared to clinical formulations (Adriamycin® and Lipodox®).

Conclusion

Incorporation of Dox in the novel LCNPs demonstrated improved antitumor efficacy and safety profile and can be a viable option for oral chemotherapy.