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Purpose: Scientific community is always searching for alternatives for cancer treatment and promoting drug repurposing is one of the ways. Rifamycin is a well-known antibiotic, that inhibits RNA synthesis and probably can be explored as cytotoxic agent. Thus, our goal was to repurpose rifamycin for breast cancer treatment using liposomes as a delivery system. Methods: Liposomes were produced by thin-film evaporation method using egg phosphatidylcholine, cholesterol and DOPE-PEG5k (70:25:5, molar ratio). Non-encapsulated drug was removed using dialysis bags and encapsulated drug was directly determined by UV spectrophotometer. Liposomes were characterized regarding size and surface charge by dynamic light scattering. Liposomes were stored at 4°C and 25°C for stability evaluation, monitoring nanoparticles parameters and drug encapsulation. Formulation biocompatibility was evaluated by hemolysis assay. Finally, cytotoxicity of rifamycin SV and liposomes was evaluated in MCF-7 and MDA-MB-231 cell lines. Results: Blank liposomes (without drug) and rifamycin-loaded liposomes showed size smaller than 100 nm and polydispersity around 0.2, with slightly negative zeta potential. Rifamycin encapsulation in liposomes was 3mg of drug/10mg of lipid films. Both formulations were stable for at least 21 days when stored at 4°C, keeping above 60% of drug encapsulated. In the concentrations tested (0.5mg/mL of drug, 2mg/mL of lipids), liposomes formulation (blank and loaded) and free rifamycin were biocompatible and non-hemolytic, since hemolysis was below 6%. Blank liposomes were not cytotoxic in tested cell lines. Free rifamycin and rifamycin-loaded liposomes demonstrated the IC50 in the same range between 41 and 46 µg/mL in 24h and 48h for both MCF-7 and MDA-MB-231. Conclusions: Rifamycin was successfully encapsulated in liposomes, leading to a stable, biocompatible, and non-hemolytic formulation. The liposomal rifamycin demonstrated strong cytotoxicity towards cancer cells similar to that of the free drug. Citation Format: Janaina Artem Ataide, Nina Filipczak, Satya Siva Kishan Yalamarty, Priscila Gava Mazzola, Vladimir P. Torchilin. Repurposing an antibiotic for breast cancer treatment using liposomes as a delivery system [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1999.

Purpose: A major hurdle in chemotherapy is multidrug resistance (MDR) observed in tumors. Downregulation of efflux proteins such as P-glycoprotein (P-gp) using small interfering RNA (siRNA) can be an effective way to treat resistant tumors. In this study, monoclonal antibody 2C5 (mAb 2C5) - PEG7k-DOPE conjugates were post-inserted into the mixed dendrimer micelles containing generation 4 (G4) polyamidoamine (PAMAM)-PEG2k-DOPE and PEG5k-DOPE. The inherent amphiphilic nature of DOPE conjugates causes the copolymers to self-assemble to form a micelle and encapsulate hydrophobic chemotherapeutic drug in its core. The siRNA electrostatically binds to the cationic charges on the G4 PAMAM dendrimer. The tumor-specific mAb 2C5 on the surface of these nano-preparations resulted in improved tumor targeting. Methods: G4 PAMAM-PEG2k-DOPE was prepared by conjugating G4 PAMAM with para-nitrophenol (pNP)-PEG2k-DOPE. To prepare 2C5-PEG7k-DOPE, mAb 2C5 was mixed with micelles containing pNP-PEG7k-DOPE and PEG5k-DOPE in sodium citrate buffer at pH 5.0 and later adjusted the pH to 8.0. In vitro evaluation of the targeted and non-targeted micelles were performed in both MDA-MB-231 and SKOV-3TR resistant cell lines. Further a xenograft MDA-MB-231 in vivo mice tumor models were performed. Results: The 2C5-conjugated mixed dendrimer micelles have a uniform size distribution with a slightly positive zeta potential. They show a stable size and zeta potential for 20 days. The morphology of the 2C5 modified micelles was confirmed using TEM imaging. A higher cellular association was observed in the micelles with the 2C5 antibody targeting using fluorescence imaging (DOPE-FITC tagged micelle) in both the cell lines. At 30 minutes the 2C5 targeted mixed dendrimer micelles showed high cellular uptake and was analyzed using flow cytometry. We further evaluated the P-gp downregulation using western blot and observed a significant downregulation of P-gp levels in the targeted formulation versus the non-targeted formulation. The in vivo tumor growth inhibition study in nude NCG 572 MDA-MB-231 tumor bearing mice showed that the immuno-micelles loaded with siMDR-1 and chemotherapeutics resulted in significantly increased therapeutic efficacy compared to non-modified mixed dendrimer micelles. Conclusions: We have evaluated the 2C5 antibody-modified mixed dendrimer micelles in different cell models, in addition to the models tested in our previous studies. We have successfully established the stability of the formulation in this study and established a 20-day shelf-life. Cellular association, internalization and P-gp downregulation studies show the superiority of the 2C5 modified dendrimer micelles upon non-targeted preparations or free actives. Citation Format: Satya Siva Kishan Yalamarty, Nina Filipczak, Xiang Li, Tanvi Vinod Pathrikar, Colin Cotter, Vladimir P. Torchilin. 2C5 antibody modified dendrimer-based mixed micelles for the treatment of multidrug resistant cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1997.

Background: Neutrophil extracellular traps (NETs) are composed of processed chromatin bound to granular and selected cytoplasmic proteins and released by neutrophils. NETs consist of smooth filaments composed of stacked nucleosomes. Fully hydrated NETs have a cloud-like appearance and occupy a space 10-15-fold larger than the volume of the cells they originate from. DNases are the enzymes that cleave extracellular DNA including NETs. Together with their protective role in microbial infections, NETs are involved in multiple pathological processes and represent key events in a variety of pathologies including cancer, autoimmunity, and cardiovascular disease. Sites of NETs concentration are dangerous for the host if the process of NETs formation becomes chronic or the mechanism of NETs removal does not work. NETosis has been linked to the development of periodontitis, cystic fibrosis, type 2 diabetes, COVID-19 or rheumatoid arthritis as well as cancer progression. Purpose: Thus, the destruction of NETs is of primary significance in many pathologies. In our approach, we are focusing on mimicking one of the natural mechanisms of destroying excessive NETs by delivering deoxyribonuclease I to the specific site of pathological NETs accumulation by modifying the nanoparticles using an anti-nucleosome monoclonal antibody (2C5). The antibody is specific to nucleosomes and can recognize histones in NETs. DNase I is U.S. Food and Drug Administration (FDA)-approved active component and is commonly used in therapeutic methods of modern medicine for cystic fibrosis to clear extracellular DNA fibers in the lungs and systemic lupus erythematosus. Recent findings have also shown the effectiveness of DNase I in the digestion of NETs. However, the low serum stability and fast deactivation by environmental stimuli have been considered as the limiting factors for clinical applications of DNase I, which can be overcome by its targeted specific delivery in pharmaceutical nanocarriers. Methods: In this study, we generate NETs in vitro using human neutrophils and HL-60 cells differentiated into granulocyte-like cells. We used interleukin-8, lipopolysaccharide from E.Coli (LPS), phorbol myristate acetate (PMA), and calcium ionophore A23187 (CI) to generate the NETs. We confirmed the specificity of 2C5 toward NETs by ELISA, which showed that it binds to NETs with the specificity like that for purified nucleohistone substrate. We further utilized that feature to create two delivery systems (liposomes and micelles) for DNAse I enzyme to destroy NETs, which was confirmed by staining NETs with SYTOX Green dye and followed by flow cytometric measurements and microscopic images. Conclusions: Our results suggest that 2C5 could be used to identify and visualize NETs and serve as a ligand for NET-targeted diagnostics and therapies. Also, we proved that our carrier can successfully deliver DNase to NETs to provide their degradation. Citation Format: Nina Filipczak, Xiang Li, Gaurav Rajan Saawant, Diptanshu Pardeshi, Bharat Ashok Rajmalani, Satya Siva Kishan Yalamarty, Vladimir P. Torchilin. 2C5-surface modified nanocarriers targeting neutrophil extracellular traps [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1995.

Farzana Parveen,1– 3 Asadullah Madni,2 Vladimir P Torchilin,1 Mubashar Rehman,4 Talha Jamshaid,2 Nina Filipczak,1 Nadia Rai,2,5 Muhammad Muzamil Khan,2,3 Muhammad Imran Khan6 1Center for Pharmaceutical Biotechnology and Nanomedicine, Northeastern University, Boston, MA, 02115, USA; 2Department of Pharmaceutics, Faculty of Pharmacy, The Islamia University of Bahawalpur, Bahawalpur, Punjab, 63100, Pakistan; 3Primary and Secondary Healthcare Department, Government of Punjab, Lahore, 54000, Pakistan; 4Department of Pharmacy, Quaid-i-Azam University, Islamabad, 45320, Pakistan; 5Department of Biomedical and Pharmaceutical Sciences, Chapman University School of Pharmacy, Irvine, CA, 92618, USA; 6Riphah Institute of Pharmaceutical Sciences, Riphah International University Lahore Campus, Lahore, 54000, PakistanCorrespondence: Asadullah Madni, Department of Pharmaceutics, Faculty of Pharmacy, The Islamia University of Bahawalpur, Bahawalpur, Punjab, 63100, Pakistan, Tel +92 62 925 5243, Fax +92 62 925 5565, Email asadpharmacist@hotmail.comBackground: Most of the traditional nanocarriers of cancer therapeutic moieties present dose-related toxicities due to the uptake of chemotherapeutic agents in normal body cells. The severe life-threatening effects of systemic chemotherapy are well documented. Doxorubicin, DOX is the most effective antineoplastic agent but with the least specific action that is responsible for severe cardiotoxicity and myelosuppression that necessitates careful monitoring while administering. Stimuli-sensitive/intelligent drug delivery systems, specifically those utilizing temperature as an external stimulus to activate the release of encapsulated drugs, have become a subject of recent research. Thus, it would be ideal to have a nanocarrier comprising safe excipients and controllable drug release capacity to deliver the drug at a particular site to minimize unwanted and toxic effects of chemotherapeutics. We have developed a simple temperature-responsive nanocarrier based on eutectic mixture of fatty acids. This study aimed to develop, physicochemically characterize and investigate the biological safety of eutectic mixture of fatty acids as a novel construct for temperature-responsive drug release potential.Methods: We have developed phase change material, PCM, based on a series of eutectic mixtures of fatty acids due to their unique and attractive physicochemical characteristics such as safety, stability, cost-effectiveness, and ease of availability. The reversible solid-liquid phase transition of PCM is responsible to hold firm or actively release the encapsulated drug. The eutectic mixtures of fatty acids (stearic acid and myristic acid) along with liquid lipid (oleic acid) were prepared to exhibit a tunable thermoresponsive platform. Doxorubicin-loaded lipid nanocarriers were successfully developed with combined hot melt encapsulation (HME) and sonication method and characterized to achieve enhanced permeability and retention (EPR) effect-based solid tumor targeting in response to exogenous temperature stimulus. The cytotoxicity against melanoma cell lines and in vivo safety studies in albino rats was also carried out.Results: Doxorubicin-loaded lipid nanocarriers have a narrow size distribution (94.59– 219.3 nm), and a PDI (0.160– 0.479) as demonstrated by photon correlation microscopy and excellent colloidal stability (Z.P value: − 22.7 to − 32.0) was developed. Transmission electron microscopy revealed their spherical morphology and characteristics of a monodispersed system. A biphasic drug release pattern with a triggered drug release at 41°C and 43°C and a sustained drug release was observed at 37°C. The thermoresponsive cytotoxic potential was demonstrated in B16F10 cancer cell lines. Hemolysis assay and acute toxicity studies with drug-free and doxorubicin lipid nanocarrier formulations provided evidence for their non-toxic nature.Conclusion: We have successfully developed a temperature-responsive tunable platform with excellent biocompatibility and intelligent drug release potential. The formulation components being from natural sources present superior characteristics in terms of cost, compatibility with normal body cells, and adaptability to preparation methods. The reported preparation method is adapted to avoid complex chemical processes and the use of organic solvents. The lipid nanocarriers with tunable thermoresponsive characteristics are promising biocompatible drug delivery systems for improved localized delivery of chemotherapeutic agents.Graphical Abstract: Keywords: nanostructured lipid carriers, lipid nanocarriers, thermoresponsive, eutectic mixtures, fatty acids, phase change materials, doxorubicin, acute toxicity studies, hemolysis assay

The innovative development of nanomedicine has promised effective treatment options compared to the standard therapeutics for cancer therapy. However, the efficiency of EPR-targeted nanodrugs is not always pleasing as it is strongly prejudiced by the heterogeneity of the enhanced permeability and retention effect (EPR). Targeting the dynamics of the EPR effect and improvement of the therapeutic effects of nanotherapeutics by using EPR enhancers is a vital approach to developing cancer therapy. Inadequate data on the efficacy of EPR in humans hampers the clinical translation of cancer drugs. Molecular targeting, physical amendment, or physiological renovation of the tumor microenvironment (TME) are crucial approaches for improving the EPR effect. Advanced imaging technologies for the visualization of EPR-induced nanomedicine distribution in tumors, and the use of better animal models, are necessary to enhance the EPR effect. This review discusses strategies to enhance EPR effect-based drug delivery approaches for cancer therapy and imaging technologies for the diagnosis of EPR effects. The effort of studying the EPR effect is beneficial, as some of the advanced nanomedicine-based EPR-enhancing approaches are currently undergoing clinical trials, which may be helpful to improve EPR-induced drug delivery and translation to clinics.

Nano silver is one of the most widely used engineering nanomaterials with antimicrobial activity against bacteria, fungi, and viruses. However, the widespread application of nano silver preparations in daily life raises concerns about public health. Although several review articles have described the toxicity of nano silver to specific major organs, an updated comprehensive review that clearly and systematically outlines the harmful effects of nano silver is lacking. This review begins with the routes of exposure to nano silver and its distribution in vivo. The toxic reactions are then discussed on three levels, from the organ to the cellular and subcellular levels. This review also provides new insights on adjusting the toxicity of nano silver by changing their size and surface functionalization and their combination with other materials to form a composite formulation. Finally, future development, challenges, and research directions are discussed.

The most important goal of regenerative medicine is to repair, restore, and regenerate tissues and organs that have been damaged as a result of an injury, congenital defect or disease, as well as reversing the aging process of the body by utilizing its natural healing potential. Regenerative medicine utilizes products of cell therapy, as well as biomedical or tissue engineering, and is a huge field for development. In regenerative medicine, stem cells and growth factor are mainly used; thus, innovative drug delivery technologies are being studied for improved delivery. Drug delivery systems offer the protection of therapeutic proteins and peptides against proteolytic degradation where controlled delivery is achievable. Similarly, the delivery systems in combination with stem cells offer improvement of cell survival, differentiation, and engraftment. The present review summarizes the significance of biomaterials in tissue engineering and the importance of colloidal drug delivery systems in providing cells with a local environment that enables them to proliferate and differentiate efficiently, resulting in successful tissue regeneration.

Amphotericin B (AmB) belongs to a group of polyene antibiotics commonly used in the treatment of systemic mycotic infections. A widely accepted mechanism of action of AmB is based on the formation of an oligomeric pore structure within the plasma membrane (PM) by interaction with membrane sterols. Although AmB binds preferentially to ergosterol, it can also bind to cholesterol in the mammalian PM and cause severe cellular toxicity. The lipid content and its lateral organization at the cell PM appear to be significant for AmB binding. Several ATP-binding cassette (ABC) transporters, including ABCA1, play a crucial role in lipid translocation, cholesterol redistribution and efflux. Here, we demonstrate that cells expressing ABCA1 are more resistant to AmB treatment, while cells lacking ABCA1 expression or expressing non-active ABCA1MM mutant display increased sensitivity. Further, a FLIM analysis of AmB-treated cells reveals a fraction of the antibiotic molecules, characterized by relatively high fluorescence lifetimes (> 6 ns), involved in formation of bulk cholesterol–AmB structures at the surface of ABCA1-expressing cells. Finally, lowering the cellular cholesterol content abolishes resistance of ABCA1-expressing cells to AmB. Therefore, we propose that ABCA1-mediated cholesterol efflux from cells induces formation of bulk cholesterol–AmB structures at the cell surface, preventing AmB cytotoxicity. Electronic supplementary material The online version of this article (10.1007/s00018-019-03154-w) contains supplementary material, which is available to authorized users.

Dendrimers comprise a specific group of macromolecules, which combine structural properties of both single molecules and long expanded polymers. The three-dimensional form of dendrimers and the extensive possibilities for use of additional substrates for their construction creates a multivalent potential and a wide possibility for medical, diagnostic and environmental purposes. Depending on their composition and structure, dendrimers have been of interest in many fields of science, ranging from chemistry, biotechnology to biochemical applications. These compounds have found wide application from the production of catalysts for their use as antibacterial, antifungal and antiviral agents. Of particular interest are peptide dendrimers as a medium for transport of therapeutic substances: synthetic vaccines against parasites, bacteria and viruses, contrast agents used in MRI, antibodies and genetic material. This review focuses on the description of the current classes of dendrimers, the methodology for their synthesis and briefly drawbacks of their properties and their use as potential therapies against infectious diseases.

Introduction: Nano formulations continue to be a very attractive venue for the development of “smart” drug delivery systems. Emerging green (organic) formulations do not require harsh chemical solvents and are easy to prepare. Solid Core Lipid Formulations: The lipid phase (l.p.) contained a solid fatty acid (lauric acid) and liquid lipid (oleic acid) with or without Doxorubicin. 55° surfactant containing an emulsifying agent (Brij-58) mixed with nonionic surfactant (Span 80) was dropwise added. The emulsion was cooled to form temperature-activated nanoparticles (TAN). Before usage, the emulsion was activated by heating to 41°C. Experiments: B16F10 melanoma, U87-MR glioblastoma, MDA-MB-231 and MCF-7 breast cancer cell lines were analyzed on a variety of quantitative Imaging platforms. Results iCyte (CompuCyte): Laser based instrument for obtaining quantitative fluorescence and light scatter measurements. We obtained single endpoint dosage response curves to compare the TAN with free Dox, and found the TANs were effective at 4-6 times lower equivalent Dox concentrations. Holomonitor (Phase Holographic Imaging): The HM4 resides in tissue culture incubators and allows long-term medium resolution holographic imaging. It offersa complete image processing library including routines for proliferation and cell tracking. We devised methods for 4-dimensional imaging (X pos. vs. Y pos. vs Time, vs. Density). Thus, we are able to monitor the temporal effects of the compounds. Cell Explorer (Nanolive): The Cell Explorer has a a rotating mirror that directs the laser in an orbit around the sample to obtain super-resolution 3D tomographs. It enables long-term time-lapse imaging via stage-top environmental chamber. It is well suited for quantifying sub cellular components such as mitochondria and lipids. HT-2 (Tomocube): The HT-2 is a label-free ultra-high resolution holotomography system complemented by fluorescence capabilities. Combined RI and fluorescence images give the highest information content of any of the platforms. Discussion: In 2012, Dixon et al described ferroptosis as a distinct new form of cell death through the iron dependent accumulation of oxidatively damaged phospholipids. They state that a diagnostic feature is mitochondrial shrinkage and collapse. We confirmed this in our tomographic imaging images. Other features that were detected and consistent with ferroptosis are loss of nuclear contents, a thickening of the nuclear membrane, and peri-nuclear mitochondrial accumulation. In 48-hour HM4 plots control cells show numerous mitotic events. Dox treated cells show cellular enlargement but no mitotic events. In the TAN population at about 20 hours, there is sudden death occurring in the entire population. Conclusion: Our experiments suggest a high potency of the newly developed TANs. Ferroptosis is the most likely mechanism of action. Citation Format: Farzana Parveen, Nina Filipczak, Asadullah Madni, Vladimir P. Torchilin, Ed Luther. Characterization of a green, temperature activated nano formulation that drives the mechanism of doxorubicin toxicity from apoptosis to ferroptosis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5327.

Neutrophils can release DNA and granular cytoplasmic proteins that form smooth filaments of stacked nucleosomes (NS). These structures, called neutrophil extracellular traps (NETs), are involved in multiple pathological processes, and NET formation and removal are clinically significant. The monoclonal antibody 2C5 has strong specificity toward intact NS but not to individual NS components, indicating that 2C5 could potentially target NS in NETs. In this study, NETs were generated in vitro using neutrophils and HL-60 cells differentiated into granulocyte-like cells. The specificity of 2C5 toward NETs was evaluated by ELISA, which showed that it binds to NETs with the specificity similar to that for purified nucleohistone substrate. Immunofluorescence showed that 2C5 stains NETs in both static and perfused microfluidic cell cultures, even after NET compaction. Modification of liposomes with 2C5 dramatically enhanced liposome association with NETs. Our results suggest that 2C5 could be used to identify and visualize NETs and serve as a ligand for NET-targeted diagnostics and therapies.

The effectiveness of existing anti-cancer therapies is based mainly on the stimulation of apoptosis of cancer cells. Most of the existing therapies are somewhat toxic to normal cells. Therefore, the quest for nontoxic, cancer-specific therapies remains. We have demonstrated the ability of liposomes containing anacardic acid, mitoxantrone and ammonium ascorbate to induce the mitochondrial pathway of apoptosis via reactive oxygen species (ROS) production by the killing of cancer cells in monolayer culture and shown its specificity towards melanoma cells. Liposomes were prepared by a lipid hydration, freeze-and-thaw (FAT) procedure and extrusion through polycarbonate filters, a remote loading method was used for dug encapsulation. Following characterization, hemolytic activity, cytotoxicity and apoptosis inducing effects of loaded nanoparticles were investigated. To identify the anticancer activity mechanism of these liposomes, ROS level and caspase 9 activity were measured by fluorescence and by chemiluminescence respectively. We have demonstrated that the developed liposomal formulations produced a high ROS level, enhanced apoptosis and cell death in melanoma cells, but not in normal cells. The proposed mechanism of the cytotoxic action of these liposomes involved specific generation of free radicals by the iron ions mechanism.

Lipid-polymer hybrid nanoparticles (LPHNP) are delivery systems for controlled drug delivery at tumor sites. The superior biocompatible properties of lipids and structural advantages of polymers can be obtained using this system for controlled drug delivery. In this study, cisplatin-loaded lipid-chitosan hybrid nanoparticles were formulated by the single step ionic gelation method based on ionic interaction of positively charged chitosan and negatively charged lipid. Formulations with various chitosan to lipid ratios were investigated to obtain the optimal particle size, encapsulation efficiency, and controlled release pattern. Transmission electron microscope and dynamic light scattering analysis demonstrated a size range of 181–245 nm and a zeta potential range of 20–30 mV. The stability of the formulation was demonstrated by thermal studies. Cytotoxicity and cellular interaction of cisplatin-loaded LPHNP were investigated using in vitro cell-based assays using the A2780 ovarian carcinoma cell line. The pharmacokinetics study in rabbits supported a controlled delivery of cisplatin with enhanced mean residence time and half-life. These studies suggest that cisplatin loaded LPHNP have promise as a platform for controlled delivery of cisplatin in cancer therapy.

Multiple factors are involved in the development of cancers and their effects on survival rate. Many are related to chemo-resistance of tumor cells. Thus, treatment with a single therapeutic agent is often inadequate for successful cancer therapy. Ideally, combination therapy inhibits tumor growth through multiple pathways by enhancing the performance of each individual therapy, often resulting in a synergistic effect. Polymeric nanoparticles prepared from block co-polymers have been a popular platform for co-delivery of combinations of drugs associated with the multiple functional compartments within such nanoparticles. Various polymeric nanoparticles have been applied to achieve enhanced therapeutic efficacy in cancer therapy. However, reported drug ratios used in such systems often vary widely. Thus, the same combination of drugs may result in very different therapeutic outcomes. In this review, we investigated polymeric co-delivery systems used in cancer treatment and the drug combinations used in these systems for synergistic anti-cancer effect. Development of polymeric co-delivery systems for a maximized therapeutic effect requires a deeper understanding of the optimal ratio among therapeutic agents and the natural heterogenicity of tumors.

Multidrug resistance (MDR) significantly decreases the therapeutic efficiency of anti-cancer drugs. Its reversal could serve as a potential method to restore the chemotherapeutic efficiency. Downregulation of MDR-related proteins with a small interfering RNA (siRNA) is a promising way to reverse the MDR effect. Additionally, delivery of small molecule therapeutics simultaneously with siRNA can enhance the efficiency of chemotherapy by dual action in MDR cell lines. Here, we conjugated the dendrimer, generation 4 polyamidoamine (G4 PAMAM), with a polyethylene glycol (PEG)-phospholipid copolymer. The amphiphilic conjugates obtained spontaneously self-assembled into a micellar nano-preparation, which can be co-loaded with siRNA onto PAMAM moieties and sparingly water-soluble chemotherapeutics into the lipid hydrophobic core. This system was co-loaded with doxorubicin (DOX) and therapeutic siRNA (siMDR-1) and tested for cytotoxicity against MDR cancer cells: human ovarian carcinoma (A2780 ADR) and breast cancer (MCF7 ADR). The combination nanopreparation effectively downregulated P-gp in MDR cancer cells and reversed the resistance towards DOX.

p53, The tumour suppressor protein encoded by P53 gene, is the most commonly altered protein in the human malignancies. MDM2 controls the p53 activity through an autoregulatory feedback loop. p53 activates the expression of MDM2 and in return, MDM2 blocks the p53 activity through various mechanisms. Nutlins, including nutlin-3, are a new class of small molecules that bind to MDM2 and prevent its interaction with p53. This antagonism results in increased p53 activity and can also re-activates the p53 pathway and resensitize the glioblastoma cells to apoptosis. Here we used nutlin-3 in combination with another potent anticancer drug, doxorubicin, to investigate the synergism between these drugs. We encapsulated both water-insoluble drugs in the PEG-PE-based micellar nanocarriers efficiently and evaluate their efficacy against U87MG cells in 2 D and 3 D models. These nanomedicine formulations successfully re-activated the p53 levels in cells, increased the apoptosis and showed strong synergistic cytotoxic effect.

Cancer causes the second-highest rate of death world-wide. A major shortcoming inherent in most of anticancer drugs is their lack of tumor selectivity. Nanodrugs for cancer therapy administered intravenously escape renal clearance, are unable to penetrate through tight endothelial junctions of normal blood vessels and remain at a high level in plasma. Over time, the concentration of nanodrugs builds up in tumors due to the EPR effect, reaching several times higher than that of plasma due to the lack of lymphatic drainage. This review will address in detail the progress and prospects of tumor-targeting via EPR effect for cancer therapy.

A series of caffeic acid derivatives were synthesized via a modified Wittig reaction which is a very important tool in organic chemistry for the construction of unsaturated carbon–carbon bonds. All reactions were performed in water medium at 90 °C. The aqueous Wittig reaction worked best when one unprotected hydroxyl group was present in the phenyl ring. The olefinations in the aqueous conditions were also conducted with good yields in the presence of two unprotected hydroxyl groups. When the number of the hydroxyl groups was increased to three, the reaction yields were worse, and the derivatives 12, 13, and 18 were obtained with 74%, 37%, and 70% yields, respectively. Nevertheless, the Wittig reaction using water as the essential medium is an elegant one-pot synthesis and a greener method, which can be a safe alternative for implementation in organic chemistry. The obtained compounds were tested for their antioxidant activity, and 12, 13, and 18 showed the highest activities. Moreover, all synthesized compounds displayed no cytotoxicity, and can therefore be used in the pharmaceutical or cosmetic industry.

Mateusz Legut, Dominik Lipka, Nina Filipczak, Adriana Piwoni, Arkadiusz Kozubek, Jerzy GubernatorDepartment of Lipids and Liposomes, Faculty of Biotechnology, University of Wrocław, Wrocław, PolandAbstract: This paper describes a novel formulation of antineoplastic drug: mitoxantrone loaded into liposomal carriers enriched with encapsulated anacardic acid in the liposomal bilayer using a vitamin C gradient. Anacardic acid is a potent epigenetic agent with anticancer activity. This is the first liposomal formulation to combine an actively encapsulated drug and anacardic acid. The liposomes were characterized in terms of basic parameters, such as size, zeta potential, optimal drug-to-lipid ratio, loading time and temperature, and stability at 4°C and in human plasma in vitro. The formulation was found to be stable, and the loading process was rapid and efficient (drug-to-lipid ratio of up to 0.3 with over 90% efficiency in 5 minutes). The cytotoxicity of these formulations was assessed using the human melanoma cell lines A375 and Hs294T and the normal human dermal fibroblast line. The results showed that anacardic acid and to a smaller extent vitamin C significantly increased the cytotoxicity of the drug towards melanoma compared to ammonium sulfate liposomes. On the other hand, vitamin C and anacardic acid both protected normal cells from damage caused by the drug. The formulation combining anacardic acid, vitamin C, and mitoxantrone showed promising results in terms of cytotoxicity and cytoprotection. Therefore, it has potential for anticancer treatment.Keywords: anacardic acid, vitamin C, ascorbic acid, liposomes, mitoxantrone, melanomaCorrigendum for this paper has been published&nbsp

The incorporation of hydrophobic drugs into liposomes improve their bioavailability and leads to increased stability and anticancer activity, along with decreased drug toxicity. Curcumin (Cur) is a natural polyphenol compound with a potent anticancer activity in pancreatic adenocarcinoma (PA). In the present study, different types of Cur-loaded liposomal formulations were prepared and characterized in terms of size, shape, zeta potential, optimal drug-to-lipid ratio and stability at 4°C, 37°C; and in human plasma in vitro. The best formulation in terms of these parameters was PEGylated, cholesterol-free formulation based upon hydrogenated soya PC (HSPC:DSPE-PEG2000:Cur, termed H5), which had a 0.05/10 molar ratio of drug-to-lipid, was found to be stable and had a 96% Cur incorporation efficiency. All Cur-loaded liposomal formulations had potent anticancer activity on the PA cancer cell lines AsPC-1 and BxPC-3, and were less toxic to a normal cell line (NHDF). Furthermore, apoptosis-induction induced by Cur in PA cells was associated with morphological changes including cell shrinkage, cytoplasmic blebbing, irregularity in shape and the externalization of cell membrane phosphatidylserine, which was preceded by an increase in intracellular reactive oxygen species (ROS) generation and caspase 3/7 activation. Because the liposomal formulations tested here, especially the H5 variant which exhibited slow release of the Cur in the human plasma test, the formulation may be stable enough to facilitate the accumulation of pharmacologically active amounts of Cur in target cancer tissue by EPR. Therefore, our formulations could serve as a promising therapeutic approach for pancreatic cancer and other cancers.

Dominik Lipka,1 Jerzy Gubernator,1 Nina Filipczak,1 Sabine Barnert,2 Regine Süss,2 Mateusz Legut,1 Arkadiusz Kozubek1 1Department of Lipids and Liposomes, University of Wroclaw, Wroclaw, Poland; 2Department of Pharmaceutical Technology, Albert Ludwigs University, Freiburg, Germany Abstract: The encapsulation of anticancer drugs in a liposome structure protects the drug during circulation and increases drug accumulation in the cancer tissue and antitumor activity while decreasing drug toxicity. This paper presents a new method of active drug loading based on a vitamin C pH/ion gradient. Formulations were characterized in terms of the following parameters: optimal external pH, time and drug-to-lipid ratio for the purpose of remote loading, and in vitro stability. In the case of the selected drug, epirubicin (EPI), its coencapsulation increases its anticancer activity through a possibly synergistic effect previously reported by other groups for a free nonencapsulated drug/vitamin C cocktail. The method also has another advantage over other remote-loading methods: it allows faster drug release through liposome destabilization at the tumor site, thanks to the very good solubility of the EPI vitamin C salt, as seen on cryogenic transmission electron microscopy images. This influences the drug-release process and increases the anticancer activity of the liposome formulation. The liposomes are characterized as stable, with very good pharmacokinetics (half-life 18.6 hours). The antitumor activity toward MCF-7 and 4T-1 breast cancer cells was higher in the case of EPI loaded via our gradient than via an ammonium sulfate gradient. Finally, the EPI liposomal formulation and the free drug were tested using the murine 4T-1 breast cancer model. The antitumor activity of the encapsulated drug was confirmed (tumor-growth inhibition over 40% from day 16 until the end of the experiment), and the free drug was shown to have no anticancer activity at the tested dose. Keywords: liposomes, epirubicin, vitamin C, antitumor activity, remote loading, ascorbic acid