Personalized Versus Precision Nanomedicine for Treatment of Ovarian Cancer

The response to treatment is substantially varied between individual patients with ovarian cancer. However, chemotherapy treatment plans rarely pay sufficient attention to the mentioned factors. Instead, standardized treatment protocols are usually employed for most ovarian cancer patients. Variations in an individual's sensitivity to drugs significantly limit the effectiveness of treatment in some patients and lead to severe toxicities in others. In the present investigation, a nanotechnology-based approach for personalized treatment of ovarian carcinoma (the most lethal type of gynecological cancer) constructed on the individual genetic profile of the patient's tumor is developed and validated. The expression of predefined genes and proteins is analyzed for each patient sample. Finally, a mixture of the complex nanocarrier-based targeted delivery system containing drug(s)/siRNA(s)/targeted peptide is selected from the pre-synthesized bank and tested in vivo on murine cancer model using cancer cells isolated from tumors of each patient. Based on the results of the present study, an innovative approach and protocol for personalized treatment of ovarian cancer are suggested and evaluated. The results of the present study clearly show the advantages and perspectives of the proposed individual treatment approach.

Inhibition of Mtorc1/2 and DNA-PK via CC-115 Synergizes with Carboplatin and Paclitaxel in Lung Squamous Cell Carcinoma

Only a small percentage (<1%) of patients with late-stage lung squamous cell carcinoma (LUSC) are eligible for targeted therapy. Because PI3K/AKT/mTOR signaling, particularly Phosphatidylinositol 3-kinase CA (PIK3CA), is dysregulated in two-thirds of LUSC, and DNA damage response pathways are enriched in LUSC, we tested whether CC-115, a dual mTORC1/2 and DNA-PK inhibitor, sensitizes LUSC to chemotherapy. We demonstrate that CC-115 synergizes with carboplatin in six of 14 NSCLC cell lines, primarily PIK3CA-mutant LUSC. Synergy was more common in cell lines that had decreased basal levels of activated AKT and DNA-PK, evidenced by reduced P-S473-AKT, P-Th308-AKT, and P-S2056-DNA-PKcs. CC-115 sensitized LUSC to carboplatin by inhibiting chemotherapy-induced AKT activation and maintaining apoptosis, particularly in PIK3CA-mutant cells lacking wild-type (WT) TP53. In addition, pathway analysis revealed that enrichments in the IFNα and IFNγ pathways were significantly associated with synergy. In multiple LUSC patient-derived xenograft and cell line tumor models, CC-115 plus platinum-based doublet chemotherapy significantly inhibited tumor growth and increased overall survival as compared with either treatment alone at clinically relevant dosing schedules. IHC and immunoblot analysis of CC-115-treated tumors demonstrated decreased P-Th308-AKT, P-S473-AKT, P-S235/236-S6, and P-S2056-DNA-PKcs, showing direct pharmacodynamic evidence of inhibited PI3K/AKT/mTOR signaling cascades. Because PI3K pathway and DNA-PK inhibitors have shown toxicity in clinical trials, we assessed toxicity by examining weight and numerous organs in PRKDC-WT mice, which demonstrated that the combination treatment does not exacerbate the clinically accepted side effects of standard-of-care chemotherapy. This preclinical study provides strong support for the further investigation of CC-115 plus chemotherapy in LUSC.

Strategy to enhance lung cancer treatment by five essential elements: inhalation delivery, nanotechnology, tumor-receptor targeting, chemo- and gene therapy

Non-Small Cell Lung Carcinoma (NSCLC), is the most common type of lung cancer (more than 80% of all cases). Small molecule Tyrosine Kinase (TK) Inhibitors acting on the Epidermal Growth Factor Receptors (EGFRs) are standard therapies for patients with NSCLC harboring EGFR-TK inhibitor-sensitizing mutations. However, fewer than 10 % of patients with NSCLC benefit from this therapy. Moreover, even the latest generation of EGFR inhibitors can cause severe systemic toxicities and are ineffective in preventing non-canonical EGFR signaling. In order to minimize and even overcome these limitations, we are proposing a novel multi-tier biotechnology treatment approach that includes: (1) suppression of all four types of EGFR-TKs by a pool of small interfering RNAs (siRNAs); (2) induction of cell death by an anticancer drug, (3) enhancing the efficiency of the treatment by the local inhalation delivery of therapeutic agents directly to the lungs (passive targeting), (4) active receptor-mediated targeting of the therapy specifically to cancer cells that in turn should minimize adverse side effects of treatment and (5) increasing the stability, solubility, and cellular penetration of siRNA and drug by using tumor targeted Nanostructured Lipid Carriers (NLC). Methods: NLCs targeted to NSCLC cells by a synthetic Luteinizing Hormone-Releasing Hormone (LHRH) decapeptide was used for the simultaneous delivery of paclitaxel (TAX) and a pool of siRNAs targeted to the four major forms of EGFR-TKs. LHRH-NLC-siRNAs-TAX nanoparticles were synthesized, characterized and tested in vitro using human lung cancer cells with different sensitivities to gefitinib (inhibitor of EGFR) and in vivo on an orthotopic NSCLC mouse model. Results: Proposed nanoparticle-based complex containing an anticancer drug, inhibitors of different types of EGFR-TKs and peptide targeted to the tumor-specific receptors (LHRH-NLC-siRNAs-TAX) demonstrated a favorable organ distribution and superior anticancer effect when compared with treatment by a single drug, inhibitor of one EGFR-TK and non-targeted therapy. Conclusions: The use of a multifunctional NLC-based delivery system substantially enhanced the efficiency of therapy for NSCLC and possibly will limit adverse side effects of the treatments. The results obtained have the potential to significantly impact the field of drug delivery and to improve the efficiency of therapy of lung and other types of cancer.

Prevention of paclitaxel-induced neuropathy by formulation approach

Chemotherapy-induced peripheral neuropathy (CIPN) is a major adverse effect of paclitaxel. Several liposome-based products have been approved and demonstrated superior efficacy and safety profiles for other drugs. The first objective of this work was to evaluate the effect of liposome formulation of paclitaxel (L-PTX) on neurotoxicity in-vitro and in-vivo in comparison to the standard Taxol® formulation. The second aim was to investigate the effect of formulation on paclitaxel biodistribution following intravenous administration in an animal model. Free paclitaxel was toxic to cell of neuronal origin (IC50 = 18.4 μg/mL) at a lower concentration than to lung cancer cells (IC50 = 59.1 μg/mL), and L-PTX demonstrated a comparable toxicity in both cell lines (IC50 = 31.8 and 33.7 μg/mL). Administration of L-PTX at 2 mg/kg per dose for a total of 4 doses on day 0, 2, 4, and 6 to rats did not result in increased sensitivity in response to mechanical or thermal stimulation of hind paws, in comparison to Taxol® administration at the same dose level that resulted in neuropathy. Paclitaxel biodisposition was evaluated for two formulations in plasma, liver, lung, brain, spinal cord, skin and muscle of rats after single intravenous dose at 6 mg/kg. The exposure to paclitaxel in brain, spinal cord, muscle, and skin was lower in the L-PTX group compared to Taxol® group. PEGylated liposomes containing paclitaxel were successfully developed and demonstrated reduced neurotoxicity in-vitro in neuronal cells and prevented development of peripheral neuropathy in-vivo. This proof of concept study showed that formulation in nanoparticles is a promising approach for reducing (or preventing) neurotoxicity caused by cancer drugs.

Inhalation treatment of cystic fibrosis with lumacaftor and ivacaftor co-delivered by nanostructured lipid carriers

Cystic fibrosis (CF), a most deadly genetic disorder, is caused by mutations of CF transmembrane receptor (CFTR) - a chloride channel present at the surface of epithelial cells. In general, two steps have to be involved in treatment of the disease: correction of cellular defects and potentiation to further increase channel opening. Consequently, a combinatorial simultaneous treatment with two drugs with different mechanisms of action, lumacaftor and ivacaftor, has been recently proposed. While lumacaftor is used to correct p.Phe508del mutation (the loss of phenylalanine at position 508) and increase the amount of cell surface-localized CFTR protein, ivacaftor serves as a CFTR potentiator that increases the open probability of CFTR channels. Since the main organ that is affected by cystic fibrosis is the lung, the delivery of drugs directly to the lungs by inhalation has a potential to enhance the efficacy of the treatment of CF and limit adverse side effects upon healthy tissues and organs. Based on our extensive experience in inhalation delivering of drugs by different nanocarriers, we selected nanostructured lipid carriers (NLC) for the delivery both drugs directly to the lungs by inhalation and tested NLC loaded with drugs in vitro (normal and CF human bronchial epithelial cells) and in vivo (homozygote/homozygote bi-transgenic mice with CF). The results show that the designed NLCs demonstrated a high drug loading efficiency and were internalized in the cytoplasm of CF cells. It was found that NLC-loaded drugs were able to restore the expression and function of CFTR protein. As a result, the combination of lumacaftor and ivacaftor delivered by lipid nanoparticles directly into the lungs was highly effective in treating lung manifestations of cystic fibrosis.

Metastatic and triple-negative breast cancer: challenges and treatment options

The major current conventional types of metastatic breast cancer (MBC) treatments include surgery, radiation, hormonal therapy, chemotherapy, or immunotherapy. Introducing biological drugs, targeted treatment and gene therapy can potentially reduce the mortality and improve the quality of life in patients with MBC. However, combination of several types of treatment is usually recommended. Triple negative breast cancer (TNBC) accounts for 10-20% of all cases of breast carcinoma and is characterized by the low expression of progesterone receptor (PR), estrogen receptor (ER), and human epidermal growth factor receptor 2 (HER2). Consequently, convenient treatments used for MBC that target these receptors are not effective for TNBC which therefore requires special treatment approaches. This review discusses the occurrence of MBC, the prognosis and predictive biomarkers of MBC, and focuses on the novel advanced tactics for treatment of MBC and TNBC. Nanotechnology-based combinatorial approach for the suppression of EGFR by siRNA and gifitinib is described.

Combinatorial treatment of idiopathic pulmonary fibrosis using nanoparticles with prostaglandin E and siRNA(s)

Inhalation delivery of prostaglandin E (PGE2) in combination with selected siRNA(s) was proposed for the efficient treatment of idiopathic pulmonary fibrosis (IPF). Nanostructured lipid carriers (NLC) were used as a delivery system for PGE2 with and without siRNAs targeted to MMP3, CCL12, and HIF1Alpha mRNAs. The model of IPF was developed in SKH1 mice by intratracheal administration of bleomycin at a dose of 1.5U/kg. Results showed that NLC-PGE2 in combination with three siRNAs delivered locally to the lungs by inhalation markedly reduced mouse body mass, substantially limited hydroxyproline content in the lungs and disturbances of the mRNAs and protein expression, restricted lung tissue damage and prevented animal mortality. Our data provide evidence that IPF can be effectively treated by inhalation of the NLC-PGE2 in combination with siRNAs delivered locally into the lungs. This effect could not be achieved by using NLC containing just PGE2 or siRNA(s) alone.

Stem cell-based gene therapy activated using magnetic hyperthermia to enhance the treatment of cancer

Stem cell-based gene therapies, wherein stem cells are genetically engineered to express therapeutic molecules, have shown tremendous potential for cancer applications owing to their innate ability to home to tumors. However, traditional stem cell-based gene therapies are hampered by our current inability to control when the therapeutic genes are actually turned on, thereby resulting in detrimental side effects. Here, we report the novel application of magnetic core-shell nanoparticles for the dual purpose of delivering and activating a heat-inducible gene vector that encodes TNF-related apoptosis-inducing ligand (TRAIL) in adipose-derived mesenchymal stem cells (AD-MSCs). By combining the tumor tropism of the AD-MSCs with the spatiotemporal MCNP-based delivery and activation of TRAIL expression, this platform provides an attractive means with which to enhance our control over the activation of stem cell-based gene therapies. In particular, we found that these engineered AD-MSCs retained their innate ability to proliferate, differentiate, and, most importantly, home to tumors, making them ideal cellular carriers. Moreover, exposure of the engineered AD-MSCS to mild magnetic hyperthermia resulted in the selective expression of TRAIL from the engineered AD-MSCs and, as a result, induced significant ovarian cancer cell death in vitro and in vivo.

Abstract 4405: Tumor-targeted nanotherapeutics

Directing anticancer agents specifically to tumors and/or cancer cells by targeting specific extracellular receptors fulfills the following three most important tasks: (1) preventing or at least substantially limiting adverse side effects on healthy tissues, (2) enhancing drug internalization by cancer cells, and (3) overcoming (at least in part) resistance mechanisms that are based on the active efflux of exogenous drugs from cancer cells.

We developed several tumor-targeted nanoscale-based formulations: various nanocarriers (liposomes, lipid nanoparticles, dendrimers, polymers, quantum dots, mesoporous silica and supermagnetic iron oxide nanoparticles); different anticancer drugs (doxorubicin, paclitaxel, camptothecin, and cisplatin); suppressors of cellular drug resistance and tumor grows (antisense oligonucleotides or siRNA targeted to BCL2, MDR1, MRP1, HIF1A, CD44 mRNA); and tumor-targeting agent - luteinizing hormone-releasing hormone (LHRH).

The proposed nanotherapeutics were tested in vitro and in vivo using established lung and ovarian cancer cell lines and highly metastatic cancer cells isolated from malignant intraperitoneal ascites from patients with advanced ovarian carcinoma. These cells were used to initiate orthotopic models of lung and ovarian cancers in nude mice that were often accompanied by the development of metastases. Tumor-targeted nanoscale-based drug formulations were delivered intravenously and intraperitoneally (for ovarian cancer) or intravenously and by inhalation (for lung cancer). Treatment with the developed therapeutics led to the suppression of targeted proteins, efficient induction of cell death, effective tumor shrinkage, prevention the development of metastases and limitation of adverse side effects.

Acknowledgements: The work was supported by R01CA100098, R01CA111766, and R01CA138533 grants from NIH.

Note: This abstract was not presented at the meeting.

Citation Format: Olga B. Garbuzenko, Andriy Kuzmov, Justin E. Sapiezynski, Oleh Taratula, Vatsal Shah, Min Zhang, Ronak Savla, Shali John, Lorna Rodriguez-Rodriguez, Tamara Minko. Tumor-targeted nanotherapeutics. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4405. doi:10.1158/1538-7445.AM2015-4405

Biodegradable Janus nanoparticles for local pulmonary delivery of hydrophilic and hydrophobic molecules to the lungs

The aim of the present work is to synthesize, characterize, and test self-assembled anisotropic or Janus particles designed to load anticancer drugs for lung cancer treatment by inhalation. The particles were synthesized using binary mixtures of biodegradable and biocompatible materials. The particles did not demonstrate cyto- and genotoxic effects. Janus particles were internalized by cancer cells and accumulated both in the cytoplasm and nuclei. After inhalation delivery, nanoparticles accumulated preferentially in the lungs of mice and retained there for at least 24 h. Two drugs or other biologically active components with substantially different aqueous solubility can be simultaneously loaded in two-phases (polymer-lipid) of these nanoparticles. In the present proof-of-concept investigation, the particles were loaded with two anticancer drugs: doxorubicin and curcumin as model anticancer drugs with relatively high and low aqueous solubility, respectively. However, there are no obstacles for loading any hydrophobic or hydrophilic chemical agents. Nanoparticles with dual load were used for their local inhalation delivery directly to the lungs of mice with orthotopic model of human lung cancer. In vivo experiments showed that the selected nanoparticles with two anticancer drugs with different mechanisms of action prevented progression of lung tumors. It should be stressed that anticancer effects of the combined treatment with two anticancer drugs loaded in the same nanoparticle significantly exceeded the effect of either drug loaded in similar nanoparticles alone.

Delivery of antisense oligonucleotides using poly(alkylene oxide)-poly(propylacrylic acid) graft copolymers in conjunction with cationic liposomes

The clinical application of gene silencing is hindered by poor stability and low delivery efficiency of naked oligonucleotides. Here, we present the in vitro and in vivo behaviors of a rationally designed, ternary, self-assembled nanoparticle complex, consisting of an anionic copolymer, cationic DOTAP liposome, and antisense oligonucleotide (AON). The multifunctional copolymers are based on backbone poly(propylacrylic acid) (PPAA), a pH-sensitive hydrophobic polymer, with grafted poly(alkylene oxides) (PAOs) varying in extent of grafting and PAO chemistry. The nanoparticle complexes with PPAA-g-PAO copolymers enhance antisense gene silencing effects in A2780 human ovarian cancer cells. A greater amount of AON is delivered to ovarian tumor xenografts using the ternary copolymer-stabilized delivery system, compared to a binary DOTAP/AON complex, following intraperitoneal injection in mice. Further, intratumoral injection of the nanoparticle complexes containing 1 mol% grafted PAO reduced tumoral bcl-2 expression by up to 60%. The data for complexes across the set of PAO polymers support a strong role for the hydrophilic-lipophilic balance of the graft copolymer in achieving serum stability and cellular uptake. Based upon these results, we anticipate that this novel nanoparticle delivery system can be extended to the delivery of plasmid DNA, siRNA, or aptamers for preclinical and clinical development.

Inhalation treatment of lung cancer: the influence of composition, size and shape of nanocarriers on their lung accumulation and retention

Objective

Various nanoparticles have been designed and tested in order to select optimal carriers for the inhalation delivery of anticancer drugs to the lungs.

Methods

The following nanocarriers were studied: micelles, liposomes, mesoporous silica nanoparticles (MSNs), poly propyleneimine (PPI) dendrimer-siRNA complexes nanoparticles, quantum dots (QDs), and poly (ethylene glycol) polymers. All particles were characterized using the following methods: dynamic light scattering, zeta potential, atomic force microscopy, in vitro cyto- and genotoxicity. In vivo organ distribution of all nanoparticles, retention in the lungs, and anticancer effects of liposomes loaded with doxorubicin were examined in nude mice after the pulmonary or intravenous delivery.

Results

Significant differences in lung uptake were found after the inhalation delivery of lipid-based and non-lipid-based nanoparticles. The accumulation of liposomes and micelles in lungs remained relatively high even 24 h after inhalation when compared with MSNs, QDs, and PPI dendrimers. There were notable differences between nanoparticle accumulation in the lungs and other organs 1 and 3 h after inhalation or intravenous administrations, but 24 h after intravenous injection all nanoparticles were mainly accumulated in the liver, kidneys, and spleen. Inhalation delivery of doxorubicin by liposomes significantly enhanced its anticancer effect and prevented severe adverse side effects of the treatment in mice bearing the orthotopic model of lung cancer.

Conclusion

The results of the study demonstrate that lipid-based nanocarriers had considerably higher accumulation and longer retention time in the lungs when compared with non-lipid-based carriers after the inhalation delivery. These particles are most suitable for effective inhalation treatment of lung cancer.

Targeted nanomedicine for suppression of CD44 and simultaneous cell death induction in ovarian cancer: an optimal delivery of siRNA and anticancer drug

PURPOSE

The proposed project is aimed at enhancing the efficiency of epithelial ovarian cancer treatment and reducing adverse side effects of chemotherapy using nanotechnology. Overexpression of the CD44 membrane receptor results in tumor initiation, growth, cancer stem cells' specific behavior, development of drug resistance, and metastases. We hypothesize that a developed cancer-targeted delivery system that combines CD44 siRNA with paclitaxel would successfully deliver its payload inside cancer cells, effectively induce cell death, and prevent metastases.

EXPERIMENTAL DESIGN

We synthesized, characterized, and tested a nanoscale-based drug delivery system (DDS) containing a modified polypropylenimine (PPI) dendrimer as a carrier; anticancer drug paclitaxel as a cell death inducer; a synthetic analog of luteinizing hormone-releasing hormone (LHRH) peptide as a tumor-targeting moiety; and siRNA targeted to CD44 mRNA. The proposed DDS was tested in vitro and in vivo using metastatic ovarian cancer cells isolated from patients with malignant ascites.

RESULTS

We found that in contrast with cells isolated from primary tumors, CD44 was highly overexpressed in metastatic cancer cells. Treatment with the proposed tumor-targeted nanoscale-based nucleic acid and DDS led to the suppression of CD44 mRNA and protein, efficient induction of cell death, effective tumor shrinkage, and prevention of adverse side effects on healthy organs.

CONCLUSION

We show a high therapeutic potential for combinatorial treatment of ovarian carcinoma with a novel DDS that effectively transports siRNA targeting to CD44 mRNA simultaneously with cytotoxic agents. Clin Cancer Res; 19(22); 6193-204. ©2013 AACR.

Inhalation treatment of pulmonary fibrosis by liposomal prostaglandin E2

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, and often fatal form of interstitial lung disease. We hypothesized that the local pulmonary delivery of prostaglandin E2 (PGE2) by liposomes can be used for the effective treatment of IPF. To test this hypothesis, we used a murine model of bleomycin-induced IPF to evaluate liposomal delivery of PGE2 topically to the lungs. Animal survival, body weight, hydroxyproline content in the lungs, lung histology, mRNA, and protein expression were studied. After inhalation delivery, liposomes accumulated predominately in the lungs. In contrast, intravenous administration led to the accumulation of liposomes mainly in kidney, liver, and spleen. Liposomal PGE2 prevented the disturbances in the expression of many genes associated with the development of IPF, substantially restricted inflammation and fibrotic injury in the lung tissues, prevented decrease in body weight, limited hydroxyproline accumulation in the lungs, and virtually eliminated mortality of animals after intratracheal instillation of bleomycin. In summary, our data provide evidence that pulmonary fibrosis can be effectively treated by the inhalation administration of liposomal form of PGE2 into the lungs. The results of the present investigations make the liposomal form of PGE2 an attractive drug for the effective inhalation treatment of idiopathic pulmonary fibrosis.

Characterization and application of a nose-only exposure chamber for inhalation delivery of liposomal drugs and nucleic acids to mice

BACKGROUND

A small nose-only exposure chamber was evaluated for inhalation delivery of drug carrier systems (DCSs) to mice for the treatment of lung cancer. The chamber then was used for inhalation delivery of an anticancer drug, antisense oligonucleotides (ASO), and small interfering RNA (siRNA) directly to the cancerous lungs of mice.

METHODS

The uniformity of particle delivery across the ports of the exposure chamber and stability of the DCS (liposomes) during continuous aerosolization by a Collison nebulizer were examined. The mean produced particle size by number was approximately 130 nm, and the mass median diameter was approximately 270 nm. The system was then used to deliver DCS containing doxorubicin (DOX) and ASO or siRNA targeted to multidrug resistance-associated protein 1 (MRP1) mRNA as suppressors of cancer cell resistance. The retention of the drug in the lungs and the effect on tumor size were compared after inhalation delivery and intravenous injection in a nu/nu mouse model of lung cancer.

RESULTS

The aerosol mass across the four inhalation ports had a coefficient of variation of less than 12%, and approximately 1.4% of the nebulized mass was available for inhalation at each port. The mean size of 130 nm of liposomal DCS did not change significantly during continuous 60-min aerosolization. For inhalation delivery of DCS with DOX+ASO/siRNA, the amount of drugs available for inhalation was lower compared with intravenous injection of DOX; however, the observed lung dose and the retention time were significantly higher. The delivery of DOX+ASO/siRNA via inhalation resulted in tumor volume reduction of more than 90%, whereas only about 40% reduction was achieved after intravenous injection of DOX.

CONCLUSIONS

The investigated exposure system is suitable for inhalation delivery of complex DCS, and its use to deliver DCS containing anticancer drugs and resistance suppressors via inhalation offered a superior method for lung cancer treatment in mice compared with intravenous injections.

Genotoxicity of different nanocarriers: possible modifications for the delivery of nucleic acids

The prevention of cyto- and genotoxicity of nanocarriers is an important task in nanomedicine. In the present investigation, we, at the first time using similar experimental conditions, compared genotoxicity of nanocarriers with different composition, architecture, size, molecular weight and charge. Poly(ethylene glycol) polymers, neutral and cationic liposomes, micelles, poly(amindo amine) and poly(propyleneimine) dendrimers, quantum dots, mesoporous silica, and supermagnetic iron oxide (SPIO) nanoparticles were studied. All nanoparticles were used in non-cytotoxic concentrations. However, even in these concentrations, positively charged cationic liposomes, dendrimers, and SPIO nanoparticles induced genotoxicity leading to the significant formation of micronuclei in cells. Negatively charged and neutral nanocarriers were not genotoxic. A strong positive correlation was found between the number of formed micronuclei and the positive charge of nanocarriers. We proposed modifications of both types of dendrimers and SPIO nanoparticles that substantially decreased their genotoxicity and allowed for an efficient intracellular delivery of nucleic acids.

Paclitaxel in tyrosine-derived nanospheres as a potential anti-cancer agent: in vivo evaluation of toxicity and efficacy in comparison with paclitaxel in Cremophor

Paclitaxel (PTX) has gained widespread clinical use yet its administration is associated with significant toxicity. In the present study, the toxicity and anti-tumor efficacy of tyrosine-derived nanospheres (NSP) for the delivery of PTX was compared to a clinical formulation of PTX in PBS-diluted Cremophor® EL (PTX-CrEL-D). Maximum tolerated dose was determined using a concentration series of PTX in NSP and CrEL-D, with toxicity assessed by measuring changes in body weight. Healthy mice administered PTX-NSP continued to gain weight normally while treatment with PTX-CrEL-D resulted in significant weight loss that failed to recover following treatment. Even at the dose of 50mg/kg, PTX-NSP showed better tolerance than 25mg/kg of PTX-CrEL-D. Xenograft studies of breast cancer revealed that the anti-tumor efficacy of PTX-NSP was equal to that of PTX-CrEL-D in tumors originating from both MDA-MB-435 and ZR-75-1 cancer lines. Larger volume of distribution and longer half-life were measured for PTX-NSP administration compared to those reported in the literature for a CrEL formulation. This trend suggests the potential for improved therapeutic index of PTX when administered via NSP. The findings reported here confirm that the NSP formulation is an efficient method for PTX administration with significant increase in maximum tolerated dose, offering possible clinical implications in the treatment of breast tumors.

Two-in-one: combined targeted chemo and gene therapy for tumor suppression and prevention of metastases

Aims: To develop an approach for the effective treatment of ovarian tumor, prevention of metastases and limitation of side effects. Materials & Methods: In order to combine chemotherapy with genotherapy, we constructed a nanoscale-based tumor-targeted system containing two anticancer drugs, two antisense oligonucleotides (suppressors of cellular resistance) and a ligand specific to receptors overexpressed in cancer cells. The system was tested in a mouse metastatic xenograft model using tumor isolates from patients with ovarian carcinoma. Results: Treatment with the proposed nanosystem decreased primary tumor, prevented intraperitoneal metastases and limited adverse side effects. Conclusions: The advantages of the proposed targeted complex treatment of primary aggressive ovarian tumor and prevention of metastases make the proposed approach promising for clinical applications.

Innovative strategy for treatment of lung cancer: targeted nanotechnology-based inhalation co-delivery of anticancer drugs and siRNA

A tumor targeted mesoporous silica nanoparticles (MSN)-based drug delivery system (DDS) was developed for inhalation treatment of lung cancer. The system was capable of effectively delivering inside cancer cells anticancer drugs (doxorubicin and cisplatin) combined with two types of siRNA targeted to MRP1 and BCL2 mRNA for suppression of pump and nonpump cellular resistance in non-small cell lung carcinoma, respectively. Targeting of MSN to cancer cells was achieved by the conjugation of LHRH peptide on the surface of MSN via poly(ethylene glycol) spacer. The delivered anticancer drugs and siRNA preserved their specific activity leading to the cell death induction and inhibition of targeted mRNA. Suppression of cellular resistance by siRNA effectively delivered inside cancer cells and substantially enhanced the cytotoxicity of anticancer drugs. Local delivery of MSN by inhalation led to the preferential accumulation of nanoparticles in the mouse lungs, prevented the escape of MSN into the systemic circulation, and limited their accumulation in other organs. The experimental data confirm that the developed DDS satisfies the major prerequisites for effective treatment of non-small cell lung carcinoma. Therefore, the proposed cancer-targeted MSN-based system for complex delivery of drugs and siRNA has high potential in the effective treatment of lung cancer.

Flexible filaments for in vivo imaging and delivery: persistent circulation of filomicelles opens the dosage window for sustained tumor shrinkage

Shape effects of synthetic carriers are largely unexplored in vivo, although recent findings suggest that flexible filaments can persist in the circulation even if microns in length. Here, to better assess biodistribution, a near-infrared fluorophore (NIRF) was incorporated into such block copolymer "filomicelles", and both in vivo and ex vivo imaging show that the majority of these wormlike micelles remain in the circulation for at least a day after intravenous injection. NIRF imaging further suggests that filomicelles convect into a tumor and some fragments can penetrate into the tumor stroma. To assess a functional effect, the hydrophobic drug paclitaxel (tax) was loaded into both filomicelles and sonication-generated spherical micelles of the same copolymer. Intravenous injection of tax-loaded filomicelles nearly doubles the maximum tolerated dose of tax in normal mice compared to tax-loaded spherical micelles. In tumor-bearing mice, the higher dose of tax produces greater and more sustained tumor shrinkage and tumor cell apoptosis. These results thus begin to address mechanisms for how nonspherical carriers deliver both imaging agents and anticancer therapeutics to solid tumors.

Internally cationic polyamidoamine PAMAM-OH dendrimers for siRNA delivery: effect of the degree of quaternization and cancer targeting

A novel cancer targeted, internally cationic and surface neutral polyamidoamine (PAMAM) dendrimer, was designed, synthesized, and evaluated as a nanocarrier for the targeted intracellular delivery of siRNA. The dendrimer contained a synthetic analog of Luteinizing hormone-releasing hormone as cancer targeting moiety. The proposed delivery system possesses the following advantages: (1) internal cationic charges for complexation with siRNA and enhanced siRNA protection; (2) low cytotoxicity; (3) lesser degree of quaternization offering free tertiary amines for potential proton sponge effect; and (4) targeting specifically to cancer cells for enhancing siRNA uptake and efficiency and potential limitation of adverse side effects of chemotherapy on healthy organs. Both nontargeted and targeted dendrimer-siRNA complexes formed compact nanometer size spherical particles, exhibited very low cytotoxicity even at the higher concentration, and efficiently penetrated cancer cells in vitro. However, only the targeted dendrimer-siRNA complex was able to substantially decrease the expression of a targeted BCL2 gene.

Co-delivery of siRNA and an anticancer drug for treatment of multidrug-resistant cancer

AIMS

To develop a novel nanomedicine approach for the treatment of multidrug-resistant (MDR) cancer by combining an anticancer drug and suppressors of cellular resistance within one multifunctional nanocarrier-based delivery system (NDS).

MATERIALS & METHODS

The NDS consisted of cationic liposomes (carrier, 100-140 nm), doxorubicin (DOX, anticancer drug), siRNA targeted to MRP1 and BCL2 mRNA (suppressors of pump and nonpump cellular-resistance, respectively). The resulting approximately 500 nm complex has a zeta potential of +4 mV.

RESULTS & DISCUSSION

The NDS provides an effective co-delivery of DOX and siRNA as well as cell-death induction and suppression of cellular resistance in MDR lung cancer cells.

CONCLUSION

We demonstrate NDS-enhanced efficiency of chemotherapy to a level that cannot be achieved by applying its components separately.

Nonviral nanoscale-based delivery of antisense oligonucleotides targeted to hypoxia-inducible factor 1 alpha enhances the efficacy of chemotherapy in drug-resistant tumor

PURPOSE

To enhance the efficacy of cancer treatment, we propose a complex approach: simultaneous delivery to the tumor of a chemotherapeutic agent and a suppressor of hypoxia-inducible factor 1 alpha (HIF1A).

EXPERIMENTAL DESIGN

The novel complex liposomal drug delivery system was developed and evaluated in vitro and in vivo on nude mice bearing xenografts of multidrug-resistant human ovarian carcinoma. The proposed novel complex drug delivery system consists of liposomes as a nanocarrier, a traditional anticancer drug (doxorubicin) as a cell death inducer, and antisense oligonucleotides targeted to HIF1A mRNA as a suppressor of cellular resistance and angiogenesis.

RESULTS

The system effectively delivers active ingredients into tumor cells, multiplies the cell death signal initiated by doxorubicin, and inhibits cellular defensive mechanisms and angiogenesis by down-regulating BCL2, HSP90, and vascular endothelial growth factor proteins. This, in turn, activates caspases, promotes apoptosis, necrosis, and tumor shrinkage. The proposed novel complex multipronged approach enhances the efficiency of chemotherapy.

CONCLUSIONS

The proposed combination therapy prevents the development of resistance in cancer cells, and thus, increases the efficacy of chemotherapy to an extent that cannot be achieved by individual components applied separately. It could form the foundation for a novel type of cancer therapy based on simultaneous delivery of an anticancer drug and a suppressor of HIF1A.

Receptor targeted polymers, dendrimers, liposomes: which nanocarrier is the most efficient for tumor-specific treatment and imaging?

To compare the influence of different characteristics of nanocarriers on the efficacy of chemotherapy and imaging, we designed, characterized, and evaluated three widely used nanocarriers: linear polymer, dendrimer and liposome in vitro and in vivo. These nanocarriers delivered the same anticancer drug (paclitaxel) and/or imaging agent (Cy5.5). A synthetic analog of LHRH peptide targeted to receptors overexpressed on the membrane of cancer cells was attached to the nanocarriers as a tumor targeting moiety. Significant differences were found between various studied non-targeted carriers in their cellular internalization, cytotoxicity, tumor and organ distribution and anticancer efficacy. LHRH peptide substantially enhanced intratumoral accumulation and anticancer efficacy of all delivery systems and minimized their adverse side effects. For the first time, the present study revealed that the targeting of nanocarriers to tumor-specific receptors minimizes the influence of the architecture, composition, size and molecular mass of nanocarriers on the efficacy of imaging and cancer treatment.