Preclinical efficacy of the camptothecin-polymer conjugate IT-101 in multiple cancer models

Advances in Nanomaterials for Immunotherapeutic Improvement of Cancer Chemotherapy

Immuno-stimulative effect of chemotherapy (ISECT) is recognized as a potential alternative to conventional immunotherapies, however, the clinical application is constrained by its inefficiency. Metronomic chemotherapy, though designed to overcome these limitations, offers inconsistent results, with effectiveness varying based on cancer types, stages, and patient-specific factors. In parallel, a wealth of preclinical nanomaterials holds considerable promise for ISECT improvement by modulating the cancer-immunity cycle. In the area of biomedical nanomaterials, current literature reviews mainly concentrate on a specific category of nanomaterials and nanotechnological perspectives, while two essential issues are still lacking, i.e., a comprehensive analysis addressing the causes for ISECT inefficiency and a thorough summary elaborating the nanomaterials for ISECT improvement. This review thus aims to fill these gaps and catalyze further development in this field. For the first time, this review comprehensively discusses the causes of ISECT inefficiency. It then meticulously categorizes six types of nanomaterials for improving ISECT. Subsequently, practical strategies are further proposed for addressing inefficient ISECT, along with a detailed discussion on exemplary nanomedicines. Finally, this review provides insights into the challenges and perspectives for improving chemo-immunotherapy by innovations in nanomaterials.

Anti-tumor activity of silymarin nanoliposomes in combination with iron: In vitro and in vivo study

Combination therapy represents a promising strategy in cancer management by reducing chemotherapy resistance and associated side effects. Silymarin (SLM) has been extensively investigated due to its potent antioxidant properties and demonstrated efficacy against cancer cells. Under certain conditions however, polyphenolic compounds may also exhibit prooxidant activity by elevating intracellular reactive oxygen species (ROS), which can harm the target cells. In this study, we hypothesized that the simultaneous administration of iron (Fe) could alter the antioxidant characteristic of SLM nanoliposomes (SLM Lip) to a prooxidant state. Hence, we first developed a SLM Lip preparation using lipid film method, and then investigated the anti-oxidant properties as well as the cytotoxicity of the liposomal preparation. We also explored the efficacy of concomitant administration of iron sucrose and SML Lip on the tumor growth and survival of mice bearing tumors. We observed that exposing cells to iron, and consecutive treatment with SLM Lip (Fe + SLM Lip) could induce greater toxicity to 4 T1 breast cancer cells compared to SLM Lip. Further, Fe + SLM Lip combination demonstrated a time-dependent effect on reducing the catalase activity compared to SLM Lip, while iron treatment did not alter cell toxicity and catalase activity. In a mouse breast cancer model, the therapeutic efficacy of Fe + SLM Lip was superior compared to SLM Lip, and the treated animals survived longer. The histopathological findings did not reveal a significant damage to the major organs, whereas the most significant tumor necrosis was evident with Fe + SLM Lip treatment. The outcomes of the present investigation unequivocally underscored the prospective use of Fe + SLM combination in the context of cancer therapy, which warrants further scrutiny.

The effect of m2 peptide targeted nanoliposomes containing crocin on induction of phenotypic change in tumor macrophages to M1 state

AIMS

Crocin has immunomodulatory and anticancer effects. In this study, crocin was used to induce the M1 phenotype in mouse tumor macrophages.

MAIN METHODS

A targeted liposomal formulation with m2 peptide was prepared and characterized to deliver crocin to the M2 macrophages present in the tumor environment. RT-qPCR and IHC were performed for in vitro and in vivo (in C26 colon carcinoma mouse model at a dose of 50 mg/kg) assessment of M1 induction, respectively.

KEY FINDINGS

In vitro results indicated that liposome modified with m2 peptide was non-toxic to macrophages and had an improved uptake by macrophages compared to the non-targeted formulation and induced M1 phenotype through an IL6-independent pathway. M2 peptide- modified liposome showed considerable tumor accumulation and anti-tumor effects and significantly shifted the phenotype of tumor macrophages towards an anti-tumor M1 phenotype.

SIGNIFICANCE

Probably the remarkable anti-tumor responses observed in this study with m2 peptide-targeted liposomal formulations containing crocin were due to the enhanced delivery of crocin to the tumor macrophage and the subsequent initiation of anti-tumor immune responses.

Targeting the tumor microenvironment by liposomal Epacadostat in combination with liposomal gp100 vaccine

Indoleamine-2,3-dioxygenase (IDO1) pathway has vital role in cancer immune escape and its upregulation leads to immunosuppressive environment which is associated with poor prognosis and progression in various cancers like melanoma. Previously, we showed the antitumoral efficacy of nanoliposomal form of Epacadostat (Lip-EPA), as an IDO1 inhibitor. Herein, we used Lip-EPA as a combination approach with liposomal gp100 (Lip-gp100) anti-cancer vaccine in melanoma model. Here, we showed that B16F10 tumor express IDO1 so using Lip-EPA will enhance the efficacy of vaccine therapy. The biodistribution of ICG-labelled liposomal form of EPA showed the remarkable accumulation of drug at tumor site. In an in vivo study, Lip-EPA enhanced the antitumor efficacy of Lip-gp100 in which the IDO mRNA expression was decreased (~ fourfold) in tumor samples. Also, we identified a significant increase in the number of infiltrated T lymphocytes (p < 0.0001) with enhanced in interferon gamma (IFN-γ) production (p < 0.0001). Additionally, Lip-EPA + Lip-gp100 significantly modulated intratumoral regulatory T cells which altogether resulted in the highest delay in tumor growth (TGD = 56.54%) and increased life span (ILS > 47.36%) in treated mice. Our study demonstrated that novel combination of Lip-EPA and Lip-gp100 was effective treatment with capability of being used in further clinical studies.

Brief review: Applications of nanocomposite in electrochemical sensor and drugs delivery

The recent advancement of nanoparticles (NPs) holds significant potential for treating various ailments. NPs are employed as drug carriers for diseases like cancer because of their small size and increased stability. In addition, they have several desirable properties that make them ideal for treating bone cancer, including high stability, specificity, higher sensitivity, and efficacy. Furthermore, they might be taken into account to permit the precise drug release from the matrix. Drug delivery systems for cancer treatment have progressed to include nanocomposites, metallic NPs, dendrimers, and liposomes. Materials’ mechanical strength, hardness, electrical and thermal conductivity, and electrochemical sensors are significantly improved using nanoparticles (NPs). New sensing devices, drug delivery systems, electrochemical sensors, and biosensors can all benefit considerably from the NPs’ exceptional physical and chemical capabilities. Nanotechnology is discussed in this article from a variety of angles, including its recent applications in the medical sciences for the effective treatment of bone cancers and its potential as a promising option for treating other complex health anomalies via the use of anti-tumour therapy, radiotherapy, the delivery of proteins, antibiotics, and vaccines, and other methods. This also brings to light the role that model simulations can play in diagnosing and treating bone cancer, an area where Nanomedicine has recently been formulated. There has been a recent uptick in using nanotechnology to treat conditions affecting the skeleton. Consequently, it will pave the door for more effective utilization of cutting-edge technology, including electrochemical sensors and biosensors, and improved therapeutic outcomes.

Cyclodextrin-Based Polymeric Drug Delivery Systems for Cancer Therapy

Cyclodextrins (CDs) are one of the most extensively studied cyclic-oligosaccharides due to their low toxicity, good biodegradability and biocompatibility, facile chemical modification, and unique inclusion capacity. However, problems such as poor pharmacokinetics, plasma membrane disruption, hemolytic effects and a lack of target specificity still exist for their applications as drug carriers. Recently, polymers have been introduced into CDs to combine the advantages of both biomaterials for the superior delivery of anticancer agents in cancer treatment. In this review, we summarize four types of CD-based polymeric carriers for the delivery of chemotherapeutics or gene agents for cancer therapy. These CD-based polymers were classified based on their structural properties. Most of the CD-based polymers were amphiphilic with the introduction of hydrophobic/hydrophilic segments and were able to form nanoassemblies. Anticancer drugs could be included in the cavity of CDs, encapsulated in the nanoparticles or conjugated on the CD-based polymers. In addition, the unique structures of CDs enable the functionalization of targeting agents and stimuli-responsive materials to realize the targeting and precise release of anticancer agents. In summary, CD-based polymers are attractive carriers for anticancer agents.

Glutathione-Responsive Nanoparticles of Camptothecin Prodrug for Cancer Therapy

Camptothecin (CPT) is a potent chemotherapeutic agent for various cancers, but the broader application of CPT is still hindered by its poor bioavailability and systemic toxicity. Here, a prodrug that releases CPT in response to glutathione (GSH), which is commonly overexpressed by cancer cells is reported. Through assembling with PEGylated lipids, the prodrug is incorporated within as-assembled nanoparticles, affording CPT with a prolonged half-life in blood circulation, enhanced tumor targetingability, and improved therapeutic efficacy. Furthermore, such prodrug nanoparticles can also promote dendritic cell maturation and tumor infiltration of CD8⁺ T cells, providing a novel strategy to improve the therapeutic efficacy of CPT.

Nanoparticles advanced from preclinical studies to clinical trials for lung cancer therapy

Lung cancer is the leading cause of cancer mortality. As a heterogeneous disease, it has different subtypes and various treatment modalities. In addition to conventional surgery, radiotherapy and chemotherapy, targeted therapy and immunotherapy have also been applied in the clinics. However, drug resistance and systemic toxicity still cannot be avoided. Based on the unique properties of nanoparticles, it provides a new idea for lung cancer therapy, especially for targeted immunotherapy. When nanoparticles are used as carriers of drugs with special physical properties, the nanodrug delivery system ensures the accuracy of targeting and the stability of drugs while increasing the permeability and the aggregation of drugs in tumor tissues, showing good anti-tumor effects. This review introduces the properties of various nanoparticles including polymer nanoparticles, liposome nanoparticles, quantum dots, dendrimers, and gold nanoparticles and their applications in tumor tissues. In addition, the specific application of nanoparticle-based drug delivery for lung cancer therapy in preclinical studies and clinical trials is discussed.

Camptothesome Potentiates PD-L1 Immune Checkpoint Blockade for Improved Metastatic Triple-Negative Breast Cancer Immunochemotherapy

In this study, we focus on investigating the therapeutic effects of camptothesome on treating metastatic triple-negative breast cancer (TNBC). We elucidate that camptothesome elicited stronger immunogenic cell death (ICD) compared to free camptothecin (CPT) and Onivyde in 4T1 TNBC cells. In addition, camptothesome is mainly internalized by the 4T1 and MDA-MB-231 cells through clathrin-mediated endocytosis based on the results of flow cytometry. Through real-time Lago optical imaging, camptothesome shows excellent tumor-targeting efficiency in orthotopic TNBC tumors. We demonstrate that camptothesome can upregulate programmed death-ligand 1 (PD-L1) in 4T1 tumors in an interferon gamma (IFN-γ)-dependent manner. Furthermore, the anti-TNBC efficacy studies reveal that camptothesome is superior to Onivyde and markedly potentiates PD-L1 immune checkpoint blockade therapy with complete lung metastasis remission in an orthotopic 4T1-Luc2 tumor model. This combination therapy eliciting robust cytotoxic T lymphocytes (CTL) response via boosting tumor-infiltrating cluster of differentiation 8 (CD8), calreticulin (CRT), high mobility group box 1 protein (HMGB-1), low-density lipoprotein receptor-related protein 1 (LRP1), IFN-γ, and granzyme B. Our work corroborates the promise of camptothesome in favorably modulating tumor immune microenvironment via inducing ICD to fortify the PD-L1 checkpoint blockade therapy for improved treatment of intractable TNBC.

Camptothesome elicits immunogenic cell death to boost colorectal cancer immune checkpoint blockade

Camptothesome is an innovative nanovesicle therapeutic comprising the sphingomyelin-derived camptothecin (CPT) lipid bilayer. In this work, we deciphered that Camptothesome was taken up by colorectal cancer (CRC) cells through primarily the clathrin-mediated endocytotic pathway and displayed the potential of eliciting robust immunogenic cancer cell death (ICD) via upregulating calreticulin, high mobility group box 1 protein (HMGB-1), and adenosine triphosphate (ATP), three hallmarks involved in the induction of ICD. In addition, use of dying MC38 tumor cells treated with Camptothesome as vaccine prevented tumor growth in 60% mice that received subsequent injection of live MC38 cells on the contralateral flank, validating Camptothesome was a legitimate ICD inducer in vivo. Camptothesome markedly reduced the acute bone marrow toxicity and gastrointestinal mucositis associated with free CPT and beat free CPT and Onivyde on anti-CRC efficacy and immune responses in a partially interferon gamma (IFN-γ)-dependent manner. Furthermore, Camptothesome enhanced the efficacy of immune checkpoint inhibitors to shrink late-stage orthotopic MC38 CRC tumors with diminished tumor metastasis and markedly prolonged mice survival.

Docetaxel in combination with metformin enhances antitumour efficacy in metastatic breast carcinoma models: a promising cancer targeting based on PEGylated liposomes

OBJECTIVES

Metformin has been shown to kill cancer stem-like cells in genetically various types of breast carcinoma. With the aim to simultaneously eradicate the bulk population of tumour cells and the rare population of cancer stem-like cells in breast cancer tissues, we used the combination chemotherapy of docetaxel (DTX) with metformin (MET). Furthermore, we introduce an active loading method based on ammonium sulphate 250 mM (SA) for encapsulating docetaxel into liposomes.

METHODS

Docetaxel and metformin encapsulated into PEGylated liposomes with two different methods based on remote or passive loading methods, respectively. The size and surface charge of the liposomes were characterized. DTX content in the nanoliposomes was measured by the high-performance liquid chromatography method. The drug release profiles were evaluated in phosphate-buffered dextrose 5% with the pH of 6.5 and 7.4. We examined the antitumour activity of Taxotere (TAX), and liposomal formulation of DTX and MET as a monotherapy or combination therapy. The biodistribution of liposomes was also investigated using 99mTc hexamethyl propylene amine oxime method in BALB/c mice bearing 4T1 breast carcinoma tumours.

KEY FINDINGS

The final formulations were prepared according to the best physicochemical characteristics which were HSPC/mPEG2000-DSPE/Chol (DTX liposomes) and HSPC/DPPG/mPEG2000-DSPE/Chol (MET liposomes), at molar ratios of 85/5/10 and (55/5/5/35), respectively. In vivo experiments showed that when free or liposomal metformin used in combination with liposomal docetaxel, they prolonged median survival time (MST) from 31 in the control group to 46 days, which demonstrates their promising effects on the survival of the 4T1 breast carcinoma mice models. Moreover, combination therapies could significantly increase life span in comparison with phosphate-buffered saline (PBS) and Taxotere groups at the same dose. Furthermore, in the combination therapy study, treatment with DTX liposomes prepared by ammonium sulphate 250 mM buffer alone resulted in similar therapeutic efficacy to combination therapy. The biodistribution study exhibited significant accumulation of DTX liposomes in the tumours due to the Enhanced Permeability and Retention effect.

CONCLUSIONS

This study also showed that metformin-based combinatorial chemotherapies have superior efficacy versus their corresponding monotherapy counterparts at same doses. The findings confirm that liposomes based on ammonium sulphate 250 mM could be as a promising formulation for efficient DTX delivering and cancer targeting and therefore merit further investigations.

Redox-sensitive doxorubicin liposome: a formulation approach for targeted tumor therapy

In this study redox-sensitive (RS) liposomes manufactured using 10,10′-diselanediylbis decanoic acid (DDA), an organoselenium RS compound, to enhance the therapeutic performance of doxorubicin (Dox). The DDA structure was confirmed by 1H NMR and LC–MS/MS. Various liposomal formulations (33 formulations) were prepared using DOPE, Egg PC, and DOPC with Tm ˂ 0 and DDA. Some formulations had mPEG₂₀₀₀-DSPE and cholesterol. After extrusion, the external phase was exchanged with sodium bicarbonate to create a pH gradient. Then, Dox was remotely loaded into liposomes. The optimum formulations indicated a burst release of 30% in the presence of 0.1% hydrogen peroxide at pH 6.5, thanks to the redox-sensitive role of DDA moieties; conversely, Caelyx (PEGylated liposomal Dox) showed negligible release at this condition. RS liposomes consisting of DOPE/Egg PC/DDA at 37.5 /60/2.5% molar ratio, efficiently inhibited C26 tumors among other formulations. The release of Dox from RS liposomes in the TME through the DDA link fracture triggered by ROS or glutathione is seemingly the prerequisite for the formulations to exert their therapeutic action. These findings suggest the potential application of such intelligent formulations in the treatment of various malignancies where the TME redox feature could be exploited to achieve an improved therapeutic response.

Amino acid coordination complex mediates cisplatin entrapment within PEGylated liposome: An implication in colorectal cancer therapy

Cis-Diaminedichloroplatinum (cisplatin, CDDP) remained among the most widely used anti-cancer agents; however, management of the dose-limiting side effects is still a great hurdle to its therapeutic potential. In the framework of this investigation, novel approach was developed for CDDP encasement within liposome based on the formation of a coordination bond between the platinum (II) atom and a carboxylic group in aspartic acid (AA) and glutamic acid (GA). We have also compared two methods of preparation based on equilibration and conventional lipid film hydration. For this, first FTIR spectra of the conjugates confirmed coordination bond between Pt and the carboxylate moieties. The PEGylated liposomes composed of HSPC, cholesterol and DPPG had a size of 134 to 197 nm and negative zeta potential (-14.20 to -20.90 mv). Cytotoxicity study revealed IC₅₀ values of <7 µg/ml for liposomes. In vivo plasma retention following iv administration indicated the potential of liposome in maintaining cisplatin levels within the circulation, while free cisplatin and cisplatin conjugates were promptly eliminated. Anti-tumor efficacy studies following iv injections at 3 mg/kg cisplatin weekly for three weeks in C26 tumor bearing BALB/c mice demonstrated the potential of the cisplatin liposomes in tumor growth inhibition. Pt-complexes were not as effective as liposomal formulations showing the crucial role of liposomes in maintaining cisplatin levels within blood circulation. Overall, the developed cisplatin liposome seems to be a promising therapeutic approach for targeting solid tumors.

A silica-based antioxidant nanoparticle for oral delivery of Camptothecin which reduces intestinal side effects while improving drug efficacy for colon cancer treatment

Camptothecin (CPT) is a potent anticancer agent for the treatment of colorectal cancer; however, it exhibits some limitations, including poor solubility, low stability, and low bioavailability via oral administration, which restrict its usability in clinical treatments. In addition, overproduction of reactive oxygen species (ROS) during chemotherapy induces drug resistance and severe intestinal side effects. In this study, silica-installed ROS scavenging nanoparticles (siRNP) with 50-60 nm in diameter were employed to overcome the aforementioned drawbacks of CPT. The solubility of CPT was significantly improved by incorporating it into the core of the nanoparticle, forming CPT-loaded siRNP (CPT@siRNP). The anticancer activity of CPT@siRNP against colorectal cancer cells (C-26) in vitro was significantly improved as compared to free CPT through higher efficiency of intracellular internalization and induction of apoptosis. Owing to its antioxidant properties, CPT@siRNP reduced cytotoxicity to normal endothelial cells, which was in sharp contrast to the high toxicity of free CPT. Oral administration of CPT and CPT@siRNP to the C-26 tumor-bearing mice exhibited antitumor activity, accompanied by effective suppression of tumor growth. Although CPT treatment suppressed tumor progression, it caused severe side effects, including intestinal damage and significant bodyweight loss. Interestingly, such noticeable side effects were not observed in the mice treated with CPT@siRNP, and the effect of tumor growth inhibition tended to be similar to or higher than that of CPT treatment. The results obtained in this study indicate that CPT@siRNP is a potential therapeutic nanomedicine for the treatment of colon cancer. STATEMENT OF SIGNIFICANCE: Here we employed silica-containing antioxidant nanoparticle (siRNP) as promising oral delivery nanocarrier of campothecin (CPT) to treat colon cancer. The design of siRNP via covalent conjugation of antioxidant nitroxide radicals and the silanol groups in the polymer backbone contributes to a significant increase in the absorption of hydrophobic drug molecules inside the core and enhances the stability of nanoparticles in the gastrointestinal environment for oral drug delivery. CPT-loaded siRNP (CPT@siRNP) significantly improved solubility of CPT. As compared to free CTP, the CPT@siRNP treatment showed a significantly higher toxicity to colon cancer cell, inhibition of cancer cell migration, and induction of apopotosis. With the antioxidant feature, siRNP also significantly suppressed the intestinal side effects caused by CPT treatment in tumor-bearing mouse model.

Anti-GD2 CAR MSCs against metastatic Ewing's sarcoma

BACKGROUND

Ewing's sarcoma (ES) is an aggressive cancer affecting children and young adults. We pre-clinically demonstrated that mesenchymal stromal/stem cells (MSCs) can deliver tumour necrosis factor-related apoptosis-inducing ligand (TRAIL) against primary ES after local injection. However, ES is often metastatic calling for approaches able to support MSC targeting to the ES multiple remote sites. Considering that the disialoganglioside GD2 is expressed by ES and to optimise MSC tumour affinity, bi-functional (BF) MSCs expressing both TRAIL and a truncated anti-GD2 chimeric antigen receptor (GD2 tCAR) were generated and challenged against ES.

METHODS

The anti-GD2 BF MSCs delivering a soluble variant of TRAIL (sTRAIL) were tested in several in vitro ES models. Tumour targeting and killing by BF MSCs was further investigated by a novel immunodeficient ES metastatic model characterized by different metastatic sites, including lungs, liver and bone, mimicking the deadly clinical scenario.

FINDINGS

In vitro data revealed both tumour affinity and killing of BF MSCs. In vivo, GD2 tCAR molecule ameliorated the tumour targeting and persistence of BF MSCs counteracting ES in lungs but not in liver.

INTERPRETATION

We here generated data on the potential effects of BF MSCs within a complex ES metastatic in vivo model, exploring also the biodistribution of MSCs. Our BF MSC-based strategy promises to pave the way for potential improvements in the therapeutic delivery of TRAIL for the treatment of metastatic ES and other deadly GD2-positive malignancies.

Nanomedicine from amphiphilizedprodrugs: Concept and clinical translation

Nanomedicines generally consisting of carrier materials with small fractions of active pharmaceutical ingredients (API) have long been used to improve the pharmacokinetics and biodistributions, augment the therapeutic efficacies and mitigate the side effects. Amphiphilizing hydrophobic/hydrophilic drugs to prodrugs capable of self-assembly into well-defined nanostructures has emerged as a facile approach to fabricating nanomedicines because this amphiphilized prodrug (APD) strategy presents many advantages, including minimized use of inert carrier materials, well-characterized prodrug structures, fixed and high drug loading contents, 100% loading efficiency, and burst-free but controlled drug release. This review comprehensively summarizes recent advances in APDs and their nanomedicines, from the rationale and the stimuli-responsive linker chemistry for on-demand drug release to their progress to the clinics, clinical performance of APDs, as well as the challenges and perspective on future development.

Antennapedia-derived positively-charged peptide faces multiple problems upon their usage as targeting ligand for liposomal doxorubicin

The positively-charged peptide antp derived from Antennapedia transcription protein is demonstrated to mediate the liposome translocation across the cell membrane. In the current investigation, we prepared a stable liposomal doxorubicin (Dox) formulation and targeted it with the antp peptide from 0 to 200 ligand/liposome. These antp-containing liposomes were investigated in terms of physical stability on storage in the refrigerator and upon incubation in blood. Also, other features like cell binding, uptake, biodistribution, and treatment efficiency were evaluated in C26 colon carcinoma BALB/c mice. The Antp in liposomes resulted in enhanced particle growth with the development of the enormously large liposomes from 2000 to 6000 nm. Upon incubation in blood, these large liposomes were removed. The antp also enhanced the cell binding affinity and cell uptake rate of the liposomes and resulted in the restriction of the cancer cell proliferation, but it failed to improve the chemotherapeutic property of the Dox-liposome. The i.v. injection of antp-liposomes (15 mg Dox/kg) caused severe body weight loss and early death incidence due to probably increased toxicity. The antp targeting offered no advantage to the Dox-liposome in the delivery of Dox to the tumor, and failed to enhance the treatment efficiency of the liposomes.

Ex vivo dendritic cell-based (DC) vaccine pulsed with a low dose of liposomal antigen and CpG-ODN improved PD-1 blockade immunotherapy

Lack of pre-existing tumor infiltrated T cells resulting in resistance to programmed cell death protein 1 (PD-1) blockade therapies can be solved by combining with anti-cancer vaccines and CpG-ODN in increasing T cell expansion and infiltration. Therefore, we prepared an ex vivo dendritic cell-based (DC) vaccine pulsed with a low dose of either liposomal or non-liposomal gp100 antigen (2.8 µg) plus CpG-ODN (800 ng) formulations and evaluated its anti-tumor activity in combination with anti-PD-1 therapy. Our results showed a combination of liposomal peptide plus CpG-ODN pulsed DC with anti-PD-1 antibody was more efficacious, as evidenced by a significant increase in T_eff/T_reg TILs with a marked fourfold elevation of IFN-γ expression level in the tumor site of treated mice which reversed resistance to PD-1 blockade in a CD8 T cell-dependent manner. Furthermore, this combination also led to a remarkable tumor remission and prolonged survival rate in melanoma-bearing mice compared to non-liposomal peptide plus CpG-ODN or single-treated liposomal peptide formulations. Our results provide essential insights to devise combining regimens to improve the efficacy of immune checkpoint blockers even by a low dose of peptide and CpG-ODN.

Perspectives on Hypoxia Signaling in Tumor Stroma

Hypoxia is a well-known characteristic of solid tumors that contributes to tumor progression and metastasis. Oxygen deprivation due to high demand of proliferating cancer cells and standard of care therapies induce hypoxia. Hypoxia signaling, mainly mediated by the hypoxia-inducible transcription factor (HIF) family, results in tumor cell migration, proliferation, metabolic changes, and resistance to therapy. Additionally, the hypoxic tumor microenvironment impacts multiple cellular and non-cellular compartments in the tumor stroma, including disordered tumor vasculature, homeostasis of ECM. Hypoxia also has a multifaceted and often contradictory influence on immune cell function, which contributes to an immunosuppressive environment. Here, we review the important function of HIF in tumor stromal components and summarize current clinical trials targeting hypoxia. We provide an overview of hypoxia signaling in tumor stroma that might help address some of the challenges associated with hypoxia-targeted therapies.

The Effect of Phase Transition Temperature on Therapeutic Efficacy of Liposomal Bortezomib

AIMS

Here, three liposomal formulations of DPPC/DPPG/Chol/DSPE-mPEG2000 (F1), DPPC/DPPG/Chol (F2) and HSPC/DPPG/Chol/DSPE-mPEG2000 (F3) encapsulating BTZ were prepared and characterized in terms of their size, surface charge, drug loading, and release profile. Mannitol was used as a trapping agent to entrap the BTZ inside the liposomal core. The cytotoxicity and anti-tumor activity of formulations were investigated in vitro and in vivo in mice bearing tumor.

BACKGROUND

Bortezomib (BTZ) is an FDA approved proteasome inhibitor for the treatment of mantle cell lymphoma and multiple myeloma. The low solubility of BTZ has been responsible for the several side effects and low therapeutic efficacy of the drug. Encapsulating BTZ in a nano drug delivery system; helps overcome such issues. Among NDDSs, liposomes are promising diagnostic and therapeutic delivery vehicles in cancer treatment.

OBJECTIVE

Evaluating anti-tumor activity of bortezomib liposomal formulations.

METHODS

Data prompted us to design and develop three different liposomal formulations of BTZ based on Tm parameter, which determines liposomal stiffness. DPPC (Tm 41°C) and HSPC (Tm 55°C) lipids were chosen as variables associated with liposome rigidity. In vitro cytotoxicity assay was then carried out for the three designed liposomal formulations on C26 and B16F0, which are the colon and melanoma cancer mouse-cell lines, respectively. NIH 3T3 mouse embryonic fibroblast cell line was also used as a normal cell line. The therapeutic efficacy of these formulations was further assessed in mice tumor models.

RESULT

MBTZ were successfully encapsulated into all the three liposomal formulations with a high entrapment efficacy of 60, 64, and 84% for F1, F2, and F3, respectively. The findings showed that liposomes mean particle diameter ranged from 103.4 to 146.8nm. In vitro cytotoxicity studies showed that liposomal-BTZ formulations had higher IC50 value in comparison to free BTZ. F2-liposomes with DPPC, having lower Tm of 41°C, showed much higher anti-tumor efficacy in mice models of C26 and B16F0 tumors compared to F3-HSPC liposomes with a Tm of 55°C. F2 formulation also enhanced mice survival compared with untreated groups, either in BALB/c or in C57BL/6 mice.

CONCLUSION

Our findings indicated that F2-DPPC-liposomal formulations prepared with Tm close to body temperature seem to be effective in reducing the side effects and increasing the therapeutic efficacy of BTZ and merits further investigation.

Antitumor Activity of NLG207 (Formerly CRLX101) in Combination with Enzalutamide in Preclinical Prostate Cancer Models

Effective treatments for patients with metastatic castration-resistant prostate cancer following disease progression on enzalutamide are currently an unmet clinical need. Simultaneous inhibition of the hypoxia-inducible factor (HIF)-1α and androgen receptor (AR) pathways has been previously shown to overcome enzalutamide resistance in vitro Combination treatment with NLG207, a nanoparticle-drug conjugate of camptothecin and inhibitor of HIF-1α, and enzalutamide was evaluated in preclinical prostate cancer models of enzalutamide resistance. The effect of NLG207 and enzalutamide on average tumor volume and tumor re-growth after 3 weeks of treatment was evaluated in vivo using the subcutaneous 22Rv1 xenograft and castrated subcutaneous VCaP xenograft models. Correlative assessments of antitumor activity were evaluated in vitro using cell proliferation and qPCR assays. NLG207 8 mg/kg alone and in combination with enzalutamide reduced average tumor volume by 93% after 3 weeks of treatment (P < 0.05) in comparison with vehicle control in the subcutaneous 22Rv1 xenograft model. Notably, the addition of NLG207 also enhanced the efficacy of enzalutamide alone in the castrated subcutaneous VCaP xenograft model, decreasing the median rate of tumor growth by 51% (P = 0.0001) in comparison with enzalutamide alone. In vitro assessments of cell proliferation and gene expression further demonstrated antitumor activity via AR-HIF-1α crosstalk inhibition. Combination treatment with NLG207 and enzalutamide was shown to be effective in preclinical prostate cancer models of enzalutamide resistance. Clinical investigation of this treatment combination is ongoing (NCT03531827).

YY1 regulated transcription-based stratification of gastric tumors and identification of potential therapeutic candidates

Gastric cancer is one of the leading causes of cancer-related death worldwide. The transcription factor YY1 regulates diverse biological processes, including cell proliferation, development, DNA damage responses, and carcinogenesis. This study was designed to explore the role of YY1 regulated transcription in gastric cancer. YY1 silencing in gastric cancer cells has resulted in the inhibition of Wnt/β-catenin, JNK/MAPK, ERK/MAPK, ER, and HIF-1α signaling pathways. Genome-wide mRNA profiling upon silencing the expression YY1 gene in gastric cancer cells and comparison with the previously identified YY1 regulated genes from other lineages revealed a moderate overlap among the YY1 regulated genes. Despite the differing genes, all the YY1 regulated gene sets were expressed in most of the intestinal subtype gastric tumors and a subset of diffuse subtype gastric tumors. Integrative functional genomic analysis of the YY1 gene sets revealed an association among the pathways Wnt/β-catenin, Rapamycin, Cyclin-D1, Myc, E2F, PDGF, and AKT. Further, the drugs capable of inhibiting YY1 mediated transcription were identified as suitable targeted therapeutic candidates for gastric tumors with activated YY1. The data emerging from the investigation would pave the way for the development of YY1-based targeted therapeutics for gastric cancer.

Preparation and characterization of PEGylated liposomal Doxorubicin targeted with leptin-derived peptide and evaluation of their anti-tumor effects, in vitro and in vivo in mice bearing C26 colon carcinoma

Employing targeting ligands on the surface of liposomes has the great potential to improve therapeutic efficacy and decreases off-target effects of liposomal formulations. In the present study, a leptin-derived peptide (Lp31) was evaluated to optimize the therapeutic efficacy of PEGylated liposomal Doxorubicin (PLD, Caelyx®). Leptin is an appetite regulatory hormone that is secreted into the blood circulation by the adipose tissue and it functions via its over expressed receptors (Ob-R) in a wide variety of cancers. Lp31, as targeting ligand, was conjugated to Maleimide-PEG2000-DSPE and then post-inserted into Caelyx. The anti-tumor activity and therapeutic efficacy of leptin modified Caelyx were evaluated and compared with Caelyx. The in vitro experiments demonstrated enhanced cytotoxicity and cellular uptake of Lp31-targeted Caelyx in C26 cell line compared to Caelyx. In BALB/c mice bearing C-26 murine carcinoma, Lp31 modified Caelyx groups exhibited significantly higher doxorubicin concentration at tumor tissue. Furthermore, Lp31 modified Caelyx at the dose of 10 mg/kg resulted in significant tumor growth inhibition and enhanced survival time compared to Caelyx. According to these results, the novel Lp31-liposomal doxorubicin offers great promise for the treatment of colon cancer and merits further investigation.

Preparation of nanoliposomes containing HER2/neu (P5+435) peptide and evaluation of their immune responses and anti-tumoral effects as a prophylactic vaccine against breast cancer

HER2/neu is an immunogenic protein inducing both humoral and cell-mediated immune responses. The antigen-specific cytotoxic T lymphocytes (CTLs) are the main effector immune cells in the anti-tumor immunity. To induce an effective CTL specific response against P5+435 single peptide derived from rat HER2/neu oncogene, we used a liposome delivery vehicle. In vivo enhancement of liposome stability and intracytoplasmic delivery of peptides are the main strategies which elevate the liposome-mediated drug delivery. Liposomes containing high transition temperature phospholipids, such as DSPC, are stable with prolonged in vivo circulation and more accessibility to the immune system. Incorporation of DOPE phospholipid results in the effective delivery of peptide into the cytoplasm via the endocytotic pathway. To this end, the P5+435 peptide was linked to Maleimide-PEG2000-DSPE and coupled on the surface of nanoliposomes containing DSPC: DSPG: Cholesterol with/without DOPE. We observed that mice vaccinated with Lip-DOPE-P5+435 formulation had the highest number of IFN-γ- producing CTLs with the highest cytotoxic activity that consequently led to significantly smallest tumor size and prolonged survival rate in the TUBO mice model. In conclusion, our study indicated that the liposomal form of P5+435 peptide containing DOPE can be regarded as a promising prophylactic anti-cancer vaccine to generate potent antigen-specific immunity.

Polymer nanomedicines

Polymer nanomedicines (macromolecular therapeutics, polymer-drug conjugates, drug-free macromolecular therapeutics) are a group of biologically active compounds that are characterized by their large molecular weight. This review focuses on bioconjugates of water-soluble macromolecules with low molecular weight drugs and selected proteins. After analyzing the design principles, different structures of polymer carriers are discussed followed by the examination of the efficacy of the conjugates in animal models and challenges for their translation into the clinic. Two innovative directions in macromolecular therapeutics that depend on receptor crosslinking are highlighted: a) Combination chemotherapy of backbone degradable polymer-drug conjugates with immune checkpoint blockade by multivalent polymer peptide antagonists; and b) Drug-free macromolecular therapeutics, a new paradigm in drug delivery.

Self-assembling prodrug nanotherapeutics for synergistic tumor targeted drug delivery

Self-assembling prodrugs represents a robust and effective nanotherapeutic approach for delivering poorly soluble anticancer drugs. With numerous intrinsic advantages, self-assembling prodrugs possess the maximum drug loading capacity, controlled drug release kinetics, prolonged blood circulation, and preferential tumor accumulation based on the enhanced permeability and retention (EPR) effect. These prodrug conjugates allow for efficient self-assembly into nanodrugs with the potential of encapsulating other therapeutic agents that have different molecular targets, enabling simultaneous temporal-spatial release of drugs for synergistic antitumor efficacy with reduced systemic side effects. The aim of this review is to summarize the recent progress of self-assembling prodrug cancer nanotherapeutics that are made through conjugating therapeutically active agents to Polyethylene glycol, Vitamin E, or drugs with different physicochemical properties via rational design, for synergistic tumor targeted drug delivery.

Statement of Significance

All current FDA-approved nanomedicines use inert biomaterials as drug delivery carriers. These biomaterials lack any therapeutic potential, contributing not only to the cost, but may also elicit severe unfavorable adverse effects. Despite the reduction in toxicity associated with the payload, these nanotherapeutics have been met with limited clinical success, likely due to the monotherapy regimen. The self-assembling prodrug (SAP) has been emerging as a powerful platform for enhancing efficacy through co-delivering other therapeutic modalities with distinct molecular targets. Herein, we opportunely present a comprehensive review article summarizing three unique approaches of making SAP for synergistic drug delivery: pegylation, vitamin E-derivatization, and drug-drug conjugation. These SAPs may inevitably pave the way for developing more efficacious, clinically translatable, combination cancer nanotherapies.

Vaccination with dendritic cells pulsed ex vivo with gp100 peptide-decorated liposomes enhances the efficacy of anti PD-1 therapy in a mouse model of melanoma

BACKGROUND

Targeting antigens to dendritic cells (DCs) via nanoparticles is a powerful strategy which improves the efficacy of ex vivo antigen-pulsed DC vaccines.

METHODS

In this study, liposomes were first decorated with gp100_25-33 self-antigen and then characterized. Then, DCs were pulsed ex vivo with liposomal gp100 and injected subcutaneously in mice bearing B16F10 established melanoma tumors in combination with anti-PD-1 therapy.

RESULTS

Treatment with liposomal pulsed DC vaccine elicited the strongest anticancer immunity and enhanced intratumoral immune responses based on infiltration of gp100-specific CD4+ and CD8+ T cells to the tumor leading to significant tumor growth regression and prolonged survival rate. Treatment with liposomal pulsed DC vaccine also markedly enhanced specific cytotoxic T lymphocytes (CTL) responses with a significant higher titer of IFN-γ in the spleen. Moreover, a significant increase of PD-1 expressing CD8+ tumor infiltrating lymphocytes (TILs) was detected in tumors.

CONCLUSION

Our results demonstrate an optimum dose of liposomal gp100 significantly increases the efficacy of anti-PD-1 therapy in mice and might be an effective strategy to overcome resistance to anti-PD-1 therapy.

Cyclodextrin as a magic switch in covalent and non-covalent anticancer drug release systems

Cancer has been a threat to human health, so its treatment is a huge challenge to the present medical field. One of commonly used methods is the controlled release of anticancer drug to reduce the dose for patients, increase the stability of drug treatment and minimize side effects. Cyclodextrin is a kind of cyclic oligosaccharide produced by amylase hydrolysis. Because cyclodextrin contains a cavity structure and active hydroxyl groups, it has a positive effect on the study of the controlled release of anticancer drugs. This article reviews the controlled release of current anticancer drugs based on cyclodextrins as a "flexible switch", and discusses the classification of different types of release systems, highlighting their role in cancer treatment. Moreover, the opportunities and challenges of cyclodextrin as a magic switch in the controlled release of anticancer drugs are discussed.

PEAMOtecan, a novel chronotherapeutic polymeric drug for brain cancer

Glioblastoma multiforme (GBM) is an aggressive and difficult to treat form of brain cancer. In this work, we report on a novel chronotherapeutic polymeric drug, PEAMOtecan, for GBM therapy. PEAMOtecan was synthesized by conjugating camptothecin, a topoisomerase I inhibitor, to our proprietary, 'clickable' and modular polyoxetane polymer platform consisting of acetylene-functionalized 3-ethyl-3-(hydroxymethyl)oxetane (EAMO) repeat units (Patent No.: US 9,421,276) via the linker 3,3'-dithiodipropionic acid (DDPA) with a disulfide bond (SS) extended by short-chain polyethylene glycol (PEG). We show that PEAMOtecan is a highly modular polymer nanoformulation that protects covalently bound CPT until slowly being released over extended periods of time dependent on the cleavage of the disulfide and ester linkages. PEAMOtecan kills glioma cells by mitotic catastrophe with p53 mutant/knockdown cells being more sensitive than matched wild type cells potentially providing cancer-specific targeting. To establish proof-of-principle therapeutic effects, we tested PEAMOtecan as monotherapy for efficacy in a mouse orthotopic glioma model. PEAMOtecan was administered by one-time, convection-enhanced delivery (CED) intra-tumorally to achieve superior distribution and extended drug release over time. In addition, the near-infrared (NIR) dye Cy5.5 was coupled to the polymer providing live-animal imaging capability to track tissue distribution and clearance of the injected polymer over time. We show that PEAMOtecan significantly improves the survival of mice harboring intra-cranial tumors (p = .0074 compared to untreated group). Altogether, these results support further development and testing of our nanoconjugate platform.

Optimization of Docetaxel Loading Conditions in Liposomes: proposing potential products for metastatic breast carcinoma chemotherapy

Docetaxel (DTX) was loaded in nanoliposomes based on a new remote loading method using mannitol and acetic acid as hydration buffer. DTX loading conditions were optimized, and the final formulations were prepared according to the best parameters which were HSPC/mPEG2000-DSPE/Chol (F1), HSPC/mPEG2000-DSPE/DPPG/Chol (F2), HSPC/mPEG2000-DSPE/DSPG/Chol (F3), at molar ratios of 85/5/10, 80/5/5/10, 80/5/5/10, respectively. DTX-liposomes were found of desired size (~115 nm) and homogeneity (PDI ≤ 0.2), high drug encapsulation efficacy (34-67%) and DTX concentration, and favorable stability. Passive loaded counterparts liposomes showed three times lower encapsulation efficacy compared to the remote loaded liposomes. The drug release of remote loaded liposomes in plasma 50% was significantly more controlled and less in comparison with their passive loaded counterparts (p < 0.0001). The IC50 values of formulations were determined on MCF-7, 4T1, TUBO, NIH/3T3 cell lines. The biodistribution of iodinated docetaxel as free or liposomal form exhibited significantly greater accumulation of DTX-liposomes in tumors than that of free docetaxel due to the EPR effect. In vivo experiment with BALB/c mice bearing 4T1 or TUBO breast carcinoma tumors also showed that DTX-liposomes could significantly delay tumor growth and prolonged the survival time in comparison with control and Taxotere groups at the similar dose of 8 mg/kg. F1 and F2 formulations were stable and showed good anti-tumor activity and merit further investigation.

Folate conjugation improved uptake and targeting of porous hydroxyapatite nanoparticles containing epirubicin to cancer cells

As hydroxyapatite (HAp) with the hexagonal crystal structure is biocompatible and bioactive. In the present study, HAp nanoparticles were synthesized and functionalized with polyethylene glycol and folic acid. The anticancer drug, epirubicin, was loaded to the folic acid-conjugated polyethylene glycol-coated HAp (FA-PEG-HAp) nanoparticles. The prepared nanoparticles were used for in vitro and in vivo experiments. Particle size analyzer showed that the hydrodynamic size of PEG-HAp and FA-PEG-HAp nanoparticles was 150.3 ± 1.5 nm and 217.2 ± 14.9 nm, respectively. The release behavior of epirubicin from nanoparticles showed an increase in the rate of release in acidic pH. The released drug in acidic pH was 2.5 fold more than pH 7.4. The results of in vitro study indicated an increase in cellular uptake of nanoparticles due to folate ligand. In vivo treatment with both PEG-HAp and FA-PEG-HAp nanoparticles had notably higher inhibition efficacy towards tumor growth than free epirubicin. In conclusion, folate conjugation provided higher uptake and better targeting of hydroxyapatite nanoparticles to cancer cells.

Effects of immunisation against PCSK9 in mice bearing melanoma

INTRODUCTION

Inhibition of proprotein convertase subtilisin/kexin 9 (PCSK9) is an established modality for the treatment of hypercholesterolaemia. However, the impact of PCSK9 inhibition in other situations such as cancer remains largely unknown. The current study was conducted to study the effects of PCSK9 inhibition on cancer endpoints in mice bearing melanoma.

MATERIAL AND METHODS

To generate antiPCSK9 antibody in vivo, a nanoliposomal antiPCSK9 vaccine adsorbed to 0.4% Alum adjuvant was subcutaneously injected in C57BL/6 mice four times with bi-weekly intervals. Two weeks after the last immunisation, mice were subcutaneously inoculated with B16F0 melanoma cells. After a tumour mass was palpable (approximately 10 mm³), the mice were randomly divided into four groups and subjected to different treatment protocols: (1) PBS (untreated control), (2) vaccine group, (3) the combination of vaccine and a single dose of liposomal doxorubicin (Doxil^®), and (4) liposomal doxorubicin (positive control) group. To determine therapeutic efficacy, mouse body weight, tumour size, and survival were monitored every three days for 36 days.

RESULTS

The nanoliposomal antiPCSK9 vaccine was found to efficiently induce specific antibodies against PCSK9 in C57BL/6 mice, thereby reducing plasma levels and function of PCSK9. Tumour volumes in the vaccinated group were not significantly different from those in the liposomal doxorubicin, combination, and control groups. The time to reach endpoint (TTE) values of the vaccine (28 ±5 days), combination (30 ±6 days), liposomal doxorubicin (34 ±2 days), and control (31 ±2 days) groups were not significantly different, either. Furthermore, the tumour growth delay (TGD) values of the vaccine (-11.5 ±15.4%), liposomal doxorubicin (7.75 ±6.5%), combination (-6 ±20.77%), and control (0 ±7.5) groups were not significantly different. Finally, there was no significant difference between the median survival time and lifespan of the vaccinated versus other tested groups.

CONCLUSIONS

The nanoliposomal PCSK9 vaccine did not adversely affect the growth of melanoma tumour nor the survival of tumour-bearing mice.

Measurement of NLG207 (formerly CRLX101) nanoparticle-bound and released camptothecin in human plasma

Camptothecin (CPT), a potent inhibitor of topoisomerase I and HIF-1α, failed to demonstrate utility as an anti-cancer agent in early clinical trial investigations, primarily due to limited clinical activity and significant toxicity attributable to unfavorable physicochemical properties (e.g. low plasma solubility, pH-labile lactone ring). NLG207 (formerly CRLX101), a nanoparticle-drug conjugate (NDC) of CPT designed to optimize plasma pharmacokinetics and facilitate drug delivery to tumors, is included as part of combination treatment in two Phase II clinical trials ongoing at the National Cancer Institute (NCT02769962 and NCT03531827). To better understand the potential for drug-drug interactions and to correlate drug exposure to clinical outcomes and pharmacodynamic biomarkers, a robust analytical method was developed to measure CPT in human plasma. Two sample processing methods were developed to quantify both NDC-bound CPT and free CPT, primarily via alteration of pH conditions. A solid-phase extraction recovered >79 % of CPT prior to quantitative analysis by ultra HPLC-MS/MS. Dynamic calibration ranges of 10 to 10,000 ng/mL and 1 to 1000 ng/mL for total and free CPT, respectively were utilized to capture clinical ranges. NLG207 NDCs demonstrated significant rates of CPT release in human plasma at room temperature after 2 h but were shown to be stable at 4 °C for 24 h and through 4 freeze/thaw cycles. This assay was used to quantitate CPT plasma concentrations in clinical samples to confirm clinical utility following NLG207 treatment in subjects with advanced prostate cancer.

Topoisomerase inhibitors: Pharmacology and emerging nanoscale delivery systems

Topoisomerase enzymes have shown unique roles in replication and transcription. These enzymes which were initially found in Escherichia coli have attracted considerable attention as target molecules for cancer therapy. Nowadays, there are several topoisomerase inhibitors in the market to treat or at least control the progression of cancer. However, significant toxicity, low solubility and poor pharmacokinetic properties have limited their wide application and these characteristics need to be improved. Nano-delivery systems have provided an opportunity to modify the intrinsic properties of molecules and also to transfer the toxic agent to the target tissues. These delivery systems leads to the re-introduction of existing molecules present in the market as novel therapeutic agents with different physicochemical and pharmacokinetic properties. This review focusses on a variety of nano-delivery vehicles used for the improvement of pharmacological properties of topoisomerase inhibitors and thus enabling their potential application as novel drugs in the market.

Mechanism of a Novel Camptothecin-Deoxycholic Acid Derivate Induced Apoptosis against Human Liver Cancer HepG2 Cells and Human Colon Cancer HCT116 Cells

BACKGROUND

Camptothecin (CPT) is known as an anticancer drug in traditional Chinese medicine. However, due to the lack of targeting, low solubility, and instability of CPT, its therapeutic applications are hampered. Therefore, we synthesized a series of CPT-bile acid analogues that obtained a national patent to improve their tumour-targeting chemotherapeutic effects on liver or colon cancers. Among these analogues, the compound G2 shows high antitumor activity with enhanced liver targeting and improved oral absorption. It is significant to further investigate the possible anticancer mechanism of G2 for its further clinical research and application.

OBJECTIVE

We aimed to unearth the anticancer mechanism of G2 in HepG2 and HCT116 cells.

METHODS

Cell viability was measured using MTT assay; cell cycle, Mitochondrial Membrane Potential (MMP), and cell apoptosis were detected by flow cytometer; ROS was measured by Fluorescent Microplate Reader; the mRNA and protein levels of cell cycle-related and apoptosis-associated proteins were examined by RT-PCR and western blot, respectively.

RESULTS

We found that G2 inhibited cells proliferation of HepG2 and HCT116 remarkably in a dosedependent manner. Moreover, G2-treatment led to S and G2/M phase arrest in both cells, which could be elucidated by the change of mRNA levels of p21, p27 and Cyclin E and the increased protein level of p21. G2 also induced dramatically ROS accumulated and MMP decreased, which contributed to the apoptosis through activation of both the extrinsic and intrinsic pathways via changing the genes and proteins expression involved in apoptosis pathway in both of HepG2 and HCT116 cells.

CONCLUSION

These findings suggested that the apoptosis in both cell lines induced by G2 was related to the extrinsic and intrinsic pathways.

Host immune response to anti-cancer camptothecin conjugated cyclodextrin-based polymers

Introduction

Efficacy and safety are critical concerns when designing drug carriers. Nanoparticles are a particular type of carrier that has gained recent attention in cancer therapeutics.

Methods

In this study, we assess the safety profile of IT-101, a nanoparticle formed by self-assembly of camptothecin (CPT) conjugated cyclodextrin-based polymers. IT-101 delivers CPT to target cancer cells in animal models of numerous human cancers and in humans. Previous data from preclinical and clinical trials indicate that IT-101 has no notable immunological side effects. However, there have been no published studies focused on evaluating the effects of IT-101 on host immune systems.

Results

In this work, we demonstrate that IT-101 diminished initial host immune response following first injection of the nanopharmaceutical and induced NK cell activation and T cell proliferation upon further IT-101 exposure. Additionally, IT-101 could attenuate tumor growth more efficiently than CPT treatment only.

Conclusions

Drugs administration in whole-body circulation may lead to poorly bioavailable in central nervous system and often has toxic effects on peripheral tissues. Conjugated with cyclodextrin-based polymers not only reduce adverse effects but also modulate the immune responses to elevate drug efficacy. These immune responses may potentially facilitate actions of immune blockage, such as PD1/PDL1 in cancer treatment.

Evaluation of the Anti-Tumor Activity of Niclosamide Nanoliposomes Against Colon Carcinoma

BACKGROUND AND AIMS

Niclosamide is an established anti-helminthic drug, which has recently been shown to inhibit the growth of various cancer cells. To exploit the potential anti-tumor activity of this drug for systemic use, the problem of low aqueous solubility should be addressed. The present study tested the in vivo anti-tumor effects of a recently developed nanoliposomal preparation of niclosamide in an experimental model of colon carcinoma.

METHODS

The cytotoxicity of nanoliposomal niclosamide on CT26 colon carcinoma cells was evaluated using the MTT test. Inhibition of tumor growth was investigated in BALB/c mice bearing CT26 colon carcinoma cells. The animals were randomly divided into 4 groups including: 1) untreated control, 2) liposomal doxorubicin (15 mg/kg; single intravenous dose), 3) liposomal niclosamide (1 mg/kg/twice a week; intravenously for 4 weeks), and 4) free niclosamide (1 mg/kg/twice a week; intravenously for 4 weeks). To study therapeutic efficacy, tumor size and survival were monitored in 2-day intervals for 40 days.

RESULTS

In vitro results indicated that nanoliposomal and free niclosamide could exert cytotoxic effects with IC50 values of 4.5 and 2.5 μM, respectively. According to in vivo studies, nanoliposomal niclosamide showed a higher growth inhibitory activity against CT26 colon carcinoma cells compared with free niclosamide as revealed by delayed tumor growth and prolongation of survival.

CONCLUSION

Nnaoliposomal encapsulation enhanced anti-tumor properties of niclosamide in an experimental model of colon carcinoma.

Clinical developments of antitumor polymer therapeutics

Polymer therapeutics encompasses polymer-drug conjugates that are nano-sized, multicomponent constructs already in the clinic as antitumor compounds, either as single agents or in combination with other organic drug scaffolds. Nanoparticle-based polymer-conjugated therapeutics are poised to become a leading delivery strategy for cancer treatments as they exhibit prolonged half-life, higher stability and selectivity, water solubility, longer clearance time, lower immunogenicity and antigenicity and often also specific targeting to tissues or cells. Compared to free drugs, polymer-tethered drugs preferentially accumulate in the tumor sites unlike conventional chemotherapy which does not discriminate between the cancer cells and healthy cells, thereby causing severe side-effects. It is also desirable that the drug reaches its site of action at a particular concentration and the therapeutic dose remains constant over a sufficiently long period of time. This can be achieved by opting for new formulations possessing polymeric systems of drug carriers. However, many challenges still remain unanswered in polymeric drug conjugates which need to be readdressed and therefore, can broaden the scope of this field. This review highlights some of the antitumor polymer therapeutics including polymer-drug conjugates, polymeric micelles, polymeric liposomes and other polymeric nanoparticles that are currently under investigation.

Potential anti-tumor effect of a nanoliposomal antiPCSK9 vaccine in mice bearing colorectal cancer

INTRODUCTION

Inhibition of proprotein convertase subtilisin/kexin 9 (PCSK9) is an effective therapeutic tool for lowering low-density lipoprotein cholesterol (LDL-C). There is no available evidence on the efficacy and safety of PCSK9 inhibitors in non-cardiovascular diseases, particularly cancer. The present study aimed to evaluate the effect of PCSK9 inhibition on cancer endpoints in mice bearing colon carcinoma, using a nanoliposomal antiPCSK9 vaccine.

MATERIAL AND METHODS

The prepared nanoliposomal antiPCSK9 vaccine was subcutaneously inoculated in BALB/c mice four times with a biweekly interval. Two weeks after the last booster, the vaccinated and unvaccinated mice were subcutaneously inoculated with CT26 colon cancer cells into the right flank. After the tumor mass became palpable, the mice were randomly divided into three groups: (1) PBS (untreated control), (2) vaccine group, and (3) pegylated liposomal doxorubicin (PLD; positive control) group. Body weight, tumor size and survival of mice were monitored for 50 days.

RESULTS

The nanoliposomal antiPCSK9 vaccine could efficiently provoke specific antibodies against PCSK9 in BALB/c mice and thereby reduced the plasma level and function of PCSK9. Tumor volume was 77% and 87.7% lower (p < 0.0001) in the vaccinated mice when compared with Doxil (liposomal doxorubicin) and control mice, respectively. Tumor size analysis showed that time to reach the endpoint of the vaccine group (47 ±11 days) was slightly but not significantly higher than PLD (46 ±2.6 days) and the control (43 ±12 days) groups. The tumor growth rates in the vaccine and PLD groups were reduced by 9.3% and 7.3, respectively, when compared with the control group. The vaccinated mice survived slightly but not significantly longer than PLD and the control mice. The median survival of the vaccine, PLD and control groups were 51, 45, and 41 days, respectively. The vaccinated mice's life was prolonged by 24.4% as compared with the control mice, while it was increased by 9.8% in the PLD group.

CONCLUSIONS

Our results revealed that PCSK9 inhibition not only exerted no harmful effects but also could moderately inhibit tumor growth, and improve lifespan and survival in mice bearing colon cancer.

Effects of immunization against PCSK9 in an experimental model of breast cancer

INTRODUCTION

Inhibition of proprotein convertase subtilisin/kexin 9 (PCSK9) is an efficient strategy for lowering low-density lipoprotein cholesterol (LDL-C). There are, however, scant data on the efficacy and safety of PCSK9 inhibitors in non-cardiovascular diseases, particularly cancer. The present study aimed to evaluate the effect of PCSK9 inhibition using a nanoliposomal antiPCSK9 vaccine on cancer behavior and endpoints in mice bearing breast tumor.

MATERIAL AND METHODS

To induce antiPCSK9 antibody in vivo, a nanoliposomal antiPCSK9 vaccine absorbed on 0.4% alum adjuvant was used. To induce tumor, BALB/c mice were subcutaneously inoculated with 4T1 breast carcinoma cells. After the tumor mass was palpable (approximately 10 mm3), the mice were randomly divided into four groups and subjected to different treatment protocols: (1) PBS (untreated control), (2) vaccine group, (3) combination of vaccine and Doxil, and (4) Doxil (positive control) group. Vaccine was subcutaneously administered to mice four times at 2-week intervals. Two weeks after the last administration, the vaccinated and non-vaccinated mice were subcutaneously inoculated with 4T1 breast carcinoma cells. To evaluate therapeutic efficacy, mouse body weight, tumor size, and survival were monitored every other day for 60 days.

RESULTS

The nanoliposomal antiPCSK9 vaccine was found to efficiently induce specific antibodies against PCSK9 in BALB/c mice, thereby decreasing plasma levels of PCSK9 and inhibiting its function. Tumor size analysis showed that time to reach endpoint (TTE) of the vaccine, combination, Doxil, and control groups was 47 ±10, 57 ±4, 60 ±4 and 39 ±9 days, respectively. Rate of tumor growth in vaccine, combination and Doxil groups was decreased by 21%, 48% and 53%, respectively, compared to the control group. Lifespan was increased by 4.2% in the vaccine group, compared with the control group. Additionally, the survival in the combination and Doxil groups was significantly higher than the vaccine and control groups.

CONCLUSIONS

Our results revealed that PCSK9 inhibition may moderately improve breast cancer outcomes while having no harmful effects in tumor-bearing mice.

Nanotechnology in the diagnosis and treatment of lung cancer

Lung cancer is an umbrella term for a subset of heterogeneous diseases that are collectively responsible for the most cancer-related deaths worldwide. Despite the tremendous progress made in understanding lung tumour biology, advances in early diagnosis, multimodal therapy and deciphering molecular mechanisms of drug resistance, overall curative outcomes remain low, especially in metastatic disease. Nanotechnology, in particular nanoparticles (NPs), continue to progressively impact the way by which tumours are diagnosed and treated. The unique physicochemical properties of materials at the nanoscale grant access to a diverse molecular toolkit that can be manipulated for use in respiratory oncology. This realisation has resulted in several clinically approved NP formulations and many more in clinical trials. However, NPs are not a panacea and have yet to be utilised to maximal effect in lung cancer, and medicine in a wider context. This review serves to: describe the complexity of lung cancer, the current diagnostic and therapeutic environment, and highlight the recent advancements of nanotechnology based approaches in diagnosis and treatment of respiratory malignancies. Finally, a brief outlook on the future directions of nanomedicine is provided; presently the full potential of the field is yet to be realised. By gleaning lessons and integrating advancements from neighbouring disciplines, nanomedicine can be elevated to a position where the current barriers that stymie full clinical impact are lifted.

Preparation of nanoliposomes linked to HER2/neu-derived (P5) peptide containing MPL adjuvant as vaccine against breast cancer

The study was aimed at evaluating antitumor and immunomodulatory effects of liposomal vaccine composed of P5 human epidermal growth factor receptor 2 (HER2)/neu-derived peptide coupled to the surface of high-temperature nanoliposomes containing distearoylphosphocholine:distearoylphosphoglycerol:Chol:dioleoylphosphatidylethanolamine (DOPE) comprising monophosphoryl lipid A (MPL) adjuvant in HER2/neu overexpressing the breast cancer model. BALB/c mice bearing TUBO carcinoma were subcutaneously immunized with formulations containing 10 µg P5 peptide and 25 µg MPL three times with 2-week intervals. To determine immuno responses in immunized mice, the amount of released interferon-γ and IL-4 were measured by the enzyme-linked immunospot method and the flow cytometric analysis on the isolated splenocytes. The results demonstrated that tumor-bearing mice immunized with Lip/DOPE/MPL/P5 formulation had the most released interferon-γ and the highest cytotoxic T lymphocyte responses that led to the lowest tumor size and the longest survival time than those of other formulations. The results achieved by Lip/DOPE/MPL/P5 formulation could make it a suitable candidate to induce effective antigen-specific tumor immunity against breast cancer.