Chemotherapeutic Drugs In Cancer Therapy Research Articles

Combination of miR159 Mimics and Irinotecan Utilizing Lipid Nanoparticles for Enhanced Treatment of Colorectal Cancer.

Colorectal cancer (CRC) ranks as the third most prevalent global malignancy, marked by significant metastasis and post-surgical recurrence, posing formidable challenges to treatment efficacy. The integration of oligonucleotides with chemotherapeutic drugs emerges as a promising strategy for synergistic CRC therapy. The nanoformulation, lipid nanoparticle (LNP), presents the capability to achieve co-delivery of oligonucleotides and chemotherapeutic drugs for cancer therapy. In this study, we constructed lipid nanoparticles, termed as LNP-I-V by microfluidics to co-deliver oligonucleotides miR159 mimics (VDX05001SI) and irinotecan (IRT), demonstrating effective treatment of CRC both in vitro and in vivo. The LNP-I-V exhibited a particle size of 118.67 ± 1.27 nm, ensuring excellent stability and targeting delivery to tumor tissues, where it was internalized and escaped from the endosome with a pH-sensitive profile. Ultimately, LNP-I-V significantly inhibited CRC growth, extended the survival of tumor-bearing mice, and displayed favorable safety profiles. Thus, LNP-I-V held promise as an innovative platform to combine gene therapy and chemotherapy for improving CRC treatment.

A novel mechanism of Dimethyl ester of Alpha-ketoglutarate in suppressing Paraquat-induced BEAS-2B cell injury by alleviating GSDME dependent pyroptosis

BackgroundAcute lung injury (ALI) induced by paraquat (PQ) progresses rapidly, leading to high mortality; however, there is no specific antidote. Our limited knowledge of the pathogenic toxicological mechanisms of PQ has hindered the development of treatments against PQ exposure. PurposePyroptosis is a form of programmed cell death recently identified as a novel molecular mechanism adopted by chemotherapeutic drugs for cancer therapy. However, the involvement of pyroptosis in PQ-induced lung injury has not been reported. Therefore, we investigated the effects of PQ on the lung tissues to elucidate the molecular mechanisms underlying its toxicity, especially its ability to induce pyroptosis. MethodsTo observe the morphological changes of BEAS-2B cells exposed to PQ, the plasma membrane damage of the cells was detected by LDH release assay, mitochondrial function and cell metabolism were detected by energy metabolism analysis. Western blotting was used to detect the protein levels of GSDMD, C-GSDMD, GSDME and N-GSDME in BEAS-2B cells. Metabolites of TCA cycle were detected by metabolomics, and the changes of TCA cycle metabolic enzymes in cells were detected by Western blotting. ResultsWe observed that PQ induced proteolytic cleavage of gasdermin E (GSDME) with concomitant cleavage of caspase 3 in BEAS-2B cells. Knockout of GSDME attenuated PQ-induced cell death. Additionally, PQ induced ROS accumulation, mitochondrial depolarisation, and mitochondrial dysfunction in these cells. PQ activated the caspase 3/GSDME pathway and damaged the cytoplasmic membrane in cells, leading to pyroptosis. We demonstrated that DMK suppressed PQ-induced pyroptosis by blocking PQ-induced caspase 3/GSDME pathway activation, reducing cellular ROS levels, and improving mitochondrial function. ConclusionThese findings provide novel insights into the previously unrecognized mechanism of GSDME-dependent pyroptosis in PQ poisoning.

Repurposing nitric oxide donating drugs in cancer therapy through immune modulation

BackgroundNitric oxide-releasing drugs are used for cardiovascular diseases; however, their effects on the tumor immune microenvironment are less clear. Therefore, this study explored the impact of nitric oxide donors on tumor progression in immune-competent mice.MethodsThe effects of three different nitric oxide-releasing compounds (SNAP, SNP, and ISMN) on tumor growth were studied in tumor-bearing mouse models. Three mouse tumor models were used: B16F1 melanoma and LL2 lung carcinoma in C57BL/6 mice, CT26 colon cancer in BALB/c mice, and LL2 lung carcinoma in NOD/SCID mice. After nitric oxide treatment, splenic cytokines and lymphocytes were analyzed by cytokine array and flow cytometry, and tumor-infiltrating lymphocytes in the TME were analyzed using flow cytometry and single-cell RNA sequencing.ResultsLow doses of three exogenous nitric oxide donors inhibited tumor growth in two immunocompetent mouse models but not in NOD/SCID immunodeficient mice. Low-dose nitric oxide donors increase the levels of splenic cytokines IFN-γ and TNF-α but decrease the levels of cytokines IL-6 and IL-10, suggesting an alteration in Th2 cells. Nitric oxide donors increased the number of CD8+ T cells with activation gene signatures, as indicated by single-cell RNA sequencing. Flow cytometry analysis confirmed an increase in infiltrating CD8+ T cells and dendritic cells. The antitumor effect of nitric oxide donors was abolished by depletion of CD8+ T cells, indicating the requirement for CD8+ T cells. Tumor inhibition correlated with a decrease in a subtype of protumor macrophages and an increase in a subset of Arg1-positive macrophages expressing antitumor gene signatures. The increase in this subset of macrophages was confirmed by flow cytometry analysis. Finally, the combination of low-dose nitric oxide donor and cisplatin induced an additive cancer therapeutic effect in two immunocompetent animal models. The enhanced therapeutic effect was accompanied by an increase in the cells expressing the gene signature of NK cell.ConclusionsLow concentrations of exogenous nitric oxide donors inhibit tumor growth in vivo by regulating T cells and macrophages. CD8+ T cells are essential for antitumor effects. In addition, low-dose nitric oxide donors may be combined with chemotherapeutic drugs in cancer therapy in the future.

Integration of phytotherapy and chemotherapy: Recent advances in anticancer molecular pathways.

Cancer is a disease characterized by abnormal and uncontrolled growth of cells, leading to invasion and metastasis to other tissues. Chemotherapy drugs are some of the primary treatments for cancer, which could detrimentally affect the cancer cells by various molecular mechanisms like apoptosis and cell cycle arrest. These treatment lines have always aligned with side effects and drug resistance. Due to their anticancer effects, medicinal herbs and their active derivative compounds are being profoundly used as complementary treatments for cancer. Many studies have shown that herbal ingredients exert antitumor activities and immune-modulation effects and have fewer side effects. On the other hand, combining phytotherapy and chemotherapy, with their synergistic effects, has gained much attention across the medical community. This review article discussed the therapeutic effects of essential herbal active ingredients combined with chemotherapeutic drugs in cancer therapy. To write this article, PubMed and Scopus database were searched with the keywords "Cancer," "Combination," "Herbal," "Traditional," and "Natural." After applying inclusion/exclusion criteria, 110 articles were considered. The study shows the anticancer effects of the active herbal ingredients by inducing apoptosis and cell cycle arrest in cancer cells, especially with a chemotherapeutic agent. This study also indicates that herbal compounds can reduce side effects and dosage, potentiate anticancer responses, and sensitize cancer cells to chemotherapy drugs.

A Novel RGD-4C-Saporin Conjugate Inhibits Tumor Growth in Mouse Models of Bladder Cancer.

Although toxin may have some advantages compared to chemotherapeutic drugs in cancer therapy, e.g. a potent cytotoxic activity and a reduced risk of resistance, their successful application in the treatments to solid tumors still remains to be fully demonstrated. In this study, we genetically modified the structure of the plant-derived single-chain ribosome inactivating protein saporin (SAP) by fusing its N-terminus to the ACDCRGDCFCG peptide (RGD-4C), an αv-integrin ligand, and explored the anti-tumor activity of the resulting protein (called RGD-SAP) in vitro and in vivo, using a model of muscle invasive bladder cancer. We found that the RGD-4C targeting domain enhances the cytotoxic activity of SAP against various tumor cell lines, in a manner dependent on αv-integrin expression levels. In a subcutaneous syngeneic model of bladder cancer, RGD-SAP significantly reduced tumor growth in a dose-dependent manner. Furthermore, systemic administration of RGD-SAP in combination with mitomycin C, a chemotherapeutic drug currently used to treat patients with bladder cancer, increased the survival of mice bearing orthotopic bladder cancer with no evidence of systemic toxicity. Overall, the results suggest that RGD-SAP represents an efficient drug that could be exploited, either alone or in combination with the state-of-the-art therapies, for the treatment of bladder cancer and, potentially, of other solid tumors.

Study of the Anticancer Potential of Plant Extracts Using Liver Tumor Microphysiological System.

Background: Plants have been considered a vital source of modern pharmaceutics since the paleolithic age. Contemporary chemotherapeutic drugs for cancer therapy are chemical entities sourced from plants. However, synthetic drugs or their derivatives come with severe to moderate side effects for human health. Hence, the quest to explore and discover plant-based novel anticancer drugs is ongoing. Anticancer activities are the primary method to estimate the potential and efficacy of an extract or compound for drug discovery. However, traditional in vitro anticancer activity assays often show poor efficacy due to the lack of in-vivo-like cellular environment. In comparison, the animal-based in vivo assays lack human genetic makeup and have ethical concerns. Aim: This study aimed to overcome the limitations of traditional cell-culture-based anticancer assays and find the most suitable assay for anticancer activity of plant extracts. We first reported utilizing a liver tumor microphysiological system in the anticancer effect assessment of plant extracts. Methodology: Methanolic extracts of Acer cappadocicum Gled were used to assess anticancer activity against liver tumor microphysiological system (MPS), and cell viability, liver function tests, and antioxidant enzyme activities were performed. Additionally, an embedded transepithelial electrical resistance sensor was utilized for the real-time monitoring of the liver tumor MPS. The results were also compared with the traditional cell culture model. Results: The study demonstrated the superiority of the TEER sensor-based liver tumor MPS by its better anticancer activity based on cell viability and biomarker analysis compared to the traditional in vitro cell culture model. The anticancer effects of the plant extracts were successfully observed in real time, and methanolic extracts of Acer cappadocicum Gled increased the alanine transaminase and aspartate aminotransferase secretion, which may reveal the different mechanisms of these extracts and suggest a clue for the future molecular study of the anticancer pathways. Conclusion: Our results show that the liver tumor microphysiological system could be a better platform for plant-based anticancer activity assessment than traditional cell culture models.

Design and Synthesis of Dual-Responsive Carbon Nanodots Loaded with Cisplatin for Targeted Therapy of Lung Cancer Therapy and Nursing Care

The use of chemotherapeutic drugs in cancer therapy is often limited by problems with administration such as insolubility, inefficient biodistribution, lack of selectivity, and inability of the drug to cross cellular barriers. To overcome these limitations, various types of drug delivery systems have been explored, and recently, carbon dots (CDs) materials have also garnered attention in the field of drug delivery. In this study, we describe the preparation, characterization, and in vitro testing of the PEGlyated carbon dots (CDs) loaded with cisplatin (CDDP) termed as (CDs@CDDP). Further, the CDs@CDDP decorated with PEGylated iRGD peptide (named as CDs@CDDP-iRGD. The electroscopic and spectroscopic methods are verified by the CDs@CDDP-iRGD. Two lung cancers (A549 and HEL-299) and a non-cancerous cell line (HUVEC) were examined for the cytotoxicity of nanoparticles in vitro. The nanoparticles effectively destroy cancer cells without damaging the non-cancerous cell lines. Also, the dual AO-EB fluorescent staining assay identified programmed cell death by morphological changes in the cells. The findings of our investigations also attest to promising reach and potency treatment and nursing care management of CDs@CDDP-iRGD nanoparticles for specific cancer therapy beyond platinum medicines. We have efficiently engineered the PEGlyated carbon dots loaded with cisplatin decorated with PEGylated iRGD peptide. The nanoparticles were confirmed by the various spectral methods (IR, UV, DLS and HR-TEM techiniques). Further, we screened the CDDP, CDs@CDDP and CDs@CDDP-iRGD, for human lung cancer cells. Additionally, CDDP, CDs@CDDP and CDs@CDDP-iRGD NPs effectively induce apoptosis in human lung cancer cells and the morphological changes were monitored through the AO-EB staining, and nuclear (Hoechst 33452) staining methods.

Orderly Curled Silica Nanosheets with a Small Size and Macromolecular Loading Pores: Synthesis and Delivery of Macromolecules To Eradicate Drug-Resistant Cancer

Hierarchically organized silica nanomaterials have shown great promise for nanomedicine. However, the synthesis of silica nanomaterials with a small size and macromolecular loading pore is still a big challenge. Herein, orderly curled silica nanosheets (OCSNs) with a ∼42 nm diameter and orderly connected large channels (∼13.4 nm) were successfully prepared for the first time. The key to the formation of the unique structure (OCSNs) is using an oil/water reaction system with high concentrations of the surfactant and alkali. The prepared OCSNs exhibit a long blood circulation halftime (0.97 h) and low internalization in the reticuloendothelial system. Notably, the large superficial channels can concurrently house large guest molecules (siRNA) and chemotherapeutic drugs. Furthermore, drug-loaded OCSNs modified with polyglutamic acids can greatly increase the accumulation of incorporated siRNA and doxorubicin in solid tumors and restrain the growth of drug-resistant orthotopic breast cancer by inducing cell apoptosis. Overall, we report the preparation of hierarchically OCSNs; their small size and macromolecular loading pores are very promising for the delivery of large guest molecules and chemotherapeutic drugs for cancer therapy.

Reduction-responsive polypeptide nanomedicines significantly inhibit progression of orthotopic osteosarcoma

Osteosarcoma (OS) is the most common malignant bone tumor with high metastasis and mortality. Neoadjuvant chemotherapy is an effective therapeutic regimen, but the clinical application is limited by the unsatisfactory efficacies and considerable side effects. In this study, the reduction-responsive polypeptide micelles based on methoxy poly(ethylene glycol)-block-poly(S-tert-butylmercapto-L-cysteine) copolymers (mPEG113-b-PBMLC4, P4M, and mPEG113-b-PBMLC9, P9M) were developed to control the delivery of doxorubicin (DOX) in OS therapy. Compared to free DOX, P4M/DOX and P9M/DOX exhibited 2.6 and 3.5 times increase in the area under the curve of pharmacokinetics, 1.6 and 2.0 times increase in tumor accumulation, and 1.6 and 1.7 times decrease of the distribution in the heart. Moreover, the selective accumulation of micelles, especially P9M/DOX, in tumors induced stronger antitumor effects on both primary and lung metastatic OSs with less systematic toxicity. These micelles with smart responsiveness to intracellular microenvironments are highly promising for the targeted delivery of clinical chemotherapeutic drugs in cancer therapy.

TNFα mediated ceramide generation triggers cisplatin induced apoptosis in B16F10 melanoma in a PKCδ independent manner

Ceramide is one of the important cellular components involved in cancer regulation and exerts its pleiotropic role in the protective immune response without exhibiting any adverse effects during malignant neoplasm. Although, the PKCδ-ceramide axis in cancer cells has been an effective target in reduction of cancer, involvement of PKCδ in inducing nephrotoxicity have become a major questionnaire. In the present study, we have elucidated the mechanism by which cisplatin exploits the ceramide to render cancer cell apoptosis leading to the abrogation of malignancy in a PKCδ independent pathway with lesser toxicity. Our study revealed that cisplatin treatment in PKCδ silenced melanoma cells induces ceramide mediated apoptosis. Moreover, cisplatin induced upregulation of the transcription factor IRF1 leading to the induction of the transcriptional activity of the TNFα promoter was evident from the pharmacological inhibition and RNA interference studies. Increased cellular expression of TNFα resulted in an elevated ceramide generation by stimulating acid-sphingomyelinase and cPLA2. Furthermore, reciprocity in the regulation of sphingosine kinase 1 (Sphk1) and sphingosine kinase 2 (Sphk2) during PKCδ independent ceramide generation was also observed during cisplatin treatment. PKCδ inhibited murine melanoma model showed reduction in nephrotoxicity along with tumor regression by ceramide generation. Altogether, the current study emphasized the unexplored signaling cascade of ceramide generation by cisplatin during PKCδ silenced condition, which is associated with increased TNFα generation. Our findings enlightened the detailed mechanistic insight of ceramide mediated signaling by chemotherapeutic drugs in cancer therapy exploring a new range of targets for cancer treatment strategies.

Cholesterol-conjugated poly(D, L-lactide)-based micelles as a nanocarrier system for effective delivery of curcumin in cancer therapy

Polymeric micelles have been widely explored preclinically as suitable delivery systems for poorly soluble chemotherapeutic drugs in cancer therapy. The present study reported the development of cholesterol (Ch)-conjugated poly(D,L-Lactide) (PLA)-based polymeric micelles (mPEG–PLA-Ch) for effective encapsulation and delivery of curcumin (CUR) at the tumor site. Cholesterol conjugation dramatically affected the particle size and improved drug loading (DL) and encapsulation efficiency (EE). mPEG–PLA-Ch-CUR showed bigger hydrodynamic diameter (104.6 ± 2.1 nm, and 169.3 ± 1.52 nm for mPEG–PLA and mPEG–PLA-Ch, respectively) due to increased size of the hydrophobic core. The newly developed polymer exhibited low critical micelles concentration (CMC) (25 μg/mL) which is close to lipid-based polymer, PEG-phosphatidyl ethanolamine (12.5 μg/mL) compared to mPEG–PLA (50 μg/mL). mPEG–PLA-Ch micelles exhibited relatively higher EE (93.74 ± 1.6%) and DL (11.86 ± 0.8%) compared to mPEG–PLA micelles (EE 91.89 ± 1.2% and DL 11.06 ± 0.8%). mPEG–PLA-Ch micelles were internalized by the cancer cells effectively and exhibited higher cytotoxicity compared to free CUR in both, murine melanoma (B16F10) and human breast cancer (MDA-MB-231) cells. mPEG–PLA-Ch exhibited satisfactory hemocompatibility indicating their potential for systemic application. Further, mPEG–PLA-Ch-CUR demonstrated higher rate of reduction of tumor volume in B16F10-xenografted tumor-bearing mice compared to free CUR. At the end of 22 days, the tumor reduced to 1.87-fold (627.72 ± 0.9 mm3 versus 1174.68 ± 1.64 mm3) compared to the treatment with free CUR. In conclusion, the experimental data in vitro and in vivo indicated that the newly developed CUR-mPEG–PLA-Ch micelles may have promising applications in solid tumors.

Tumor microenvironment-responsive micelles for pinpointed intracellular release of doxorubicin and enhanced anti-cancer efficiency

Internal stimuli, such as intracellular lysosomal pH, enzyme, redox and reduction, can be applied to improve biological specificity of chemotherapeutic drugs for cancer therapy. Thus, functionalized copolymers based on their response to specific microenvironment of tumor regions have been designed as smart drug vesicles for enhanced anti-cancer efficiency and reduced side effects. Herein, we reported dually pH/reduction-responsive novel micelles based on self-assembly of carboxymethyl chitosan-cysteamine-N-acetyl histidine (CMCH-SS-NA) and doxorubicin (DOX). The tailor-made dually responsive micelles demonstrated favorable stability in normal physiological environment and triggered rapid drug release in acidic and/or reduction environment. Additionally, the nanocarriers responded to the intracellular environment in an ultra-fast manner within several minutes, which led to the pinpointed release of DOX in tumor cells effectively and ensured higher DOX concentrations within tumor areas with the aid of targeted delivery, thereby leading to enhanced tumor ablation. Thus, this approach with sharp drug release behavior represented a versatile strategy to provide a promising paradigm for cancer therapy.

Reducible self-assembling cationic polypeptide-based micelles mediate co-delivery of doxorubicin and microRNA-34a for androgen-independent prostate cancer therapy

The co-delivery of chemotherapeutic drugs and microRNAs (miR) represents a promising strategy for tumor therapy due to the synergistic effect achieved. In the present study, hydrophobic doxorubicin (DOX) and negatively charged miR-34a were simultaneously delivered via a reducible self-assembling disulfide cross-linked stearyl-peptide-based micellar system (SHRss) using poly(l-arginine)-poly(l-histidine)-stearoyl as the copolymer building unit. The nanoscale SHRss micelles exhibited a low critical micelle concentration (CMC) with positive surface charge. In addition, the present micellar system facilitated the escape of miR-34a from the endosome and release of DOX into the cell nucleus, leading to the downregulation of silent information regulator 1 (SIRT1) expression and inhibition of DU145 and PC3 androgen-independent prostate cancer cell proliferation. In addition, DOX and miR-34a, delivered by SHRss micelles, passively targeted tumor tissue. Furthermore, a synergistic anti-proliferative effect was observed compared with DOX or miR-34a treatment alone in vivo. Our results demonstrate that the SHRss micelles developed in the present study represent a promising approach for combined delivery of gene agents and hydrophobic chemotherapeutic drugs in cancer therapy.

Reversing of multidrug resistance breast cancer by co-delivery of P-gp siRNA and doxorubicin via folic acid-modified core-shell nanomicelles

Multidrug resistance (MDR) remains one of major limitation for the successful treatment of many cancers including breast cancer. Co-delivery of chemotherapeutic drugs and small interfering RNA (siRNA) has been developed because of its ability to generate synergistic anticancer effects via different mechanisms of action, to reverse MDR and increase the efficacy of chemotherapeutic drugs in cancer therapy. Herein, we employed a kind of efficient multifunctional tumor targeted nanomicelles (PECL3) for the co-delivery of hydrophobic anti-cancer drugs and siRNA. This kind of nanomicelles were constructed by folic acid (FA)-decorated PEG-b-(PCL-g-PEI)-b-PCL triblock copolymers, which were synthesized through “click chemistry” and “ring opening” polymerization. Driven by the “core-shell” structure and the electrostatic interaction, this triblock copolymer could efficiently encapsulate P-glycoprotein (P-gp) siRNA and doxorubicin (DOX). The obtained nanomicelles can prevent renal clearance, RNase degradation and aggregation in circulation. Compared to the non-specific delivery, these FA functionalized nanomicelles could efficiently deliver P-gp siRNA to reducing both P-gp expression levels and IC50 value of the DOX in DOX-resistant breast cancer cells (MCF-7/ADR). Additionally, in vivo results showed that DOX loaded PECL3 (D-PECL3) micelles could reduce toxicity of DOX on nontarget tissues and significantly inhibited MCF-7/ADR tumor growth through encapsulating DOX in the micelles and deliver them to target tumor region. Taken together, these results proof that PECL3 micelles could co-deliver siRNA and drug to inhibit MDR tumor growth. These results suggested that the co-delivery of DOX and siRNA in tumor-targeting nanomicelles could excite synergistic effect of gene therapy and chemotherapy, thus can efficiently reverse MDR cancer and kill the cancer cells.

Exploring naturally occurring ivy nanoparticles as an alternative biomaterial

Arabinoglactan protein (AGP)-rich nanoparticles obtained from the sticky exudates of Hedera helix (English ivy), have shown promising potential to be used in nanomedicine owing to their excellent aqueous solubility, low intrinsic viscosity, biocompatibility, and biodegradability. In this study, the feasibilities of utilizing ivy nanoparticles (INPs) as nano-carriers for delivering chemotherapeutic drugs in cancer therapy and as nano-fillers to develop novel scaffolds for tissue engineering in regenerative medicine are evaluated. Via electrostatic and hydrophobic interactions, pH-responsive nanoconjugates are formed between the INPs and the doxorubicin (DOX) with an entrapment ratio of 77.9±3.9%. While the INPs show minimal cytotoxicity, the formed INP-DOX conjugates exhibit substantially stronger cytotoxic activity than free DOX against multiple cancer cell lines, suggesting a synergistic effect is established upon conjugation. The anti-cancer effects of the INP-DOX conjugates are further evaluated via in vivo xenograft assays by subcutaneously implanting DOX resistant cell line, SW620/Ad-300, into nude mice. The tumor volumes in mice treated with the INP-DOX conjugates are significantly less than those of the mice treated with free DOX. In addition, the INPs are further exploited as nano-fillers to develop fibrous scaffolds with collagen, via mimicking the porous matrix where the INPs are embedded under natural condition. Enhanced adhesion of smooth muscle cells (SMCs) and accelerated proliferation of mouse aortic SMCs are observed in this newly constructed scaffold. Overall, the results obtained from the present study suggest great potential of the INPs to be used as biocompatible nanomaterials in nanomedicine. The AGP-rich INP renders a glycoprotein architecture that is amenable for modification according to the functional designs, capable of being developed as versatile nanomaterials for extensive biomedical applications. Statement of SignificanceNaturally occurring organic nanomaterials have drawn increasing interest for their potential biomedical applications in recent years. In this study, a new type of naturally occurring nanoparticles obtained from the sticky exudates on the adventitious roots of English ivy (H. helix), was explored for its potential biomedical application. In particular, the feasibilities of utilizing ivy nanoparticles (INPs) as nano-carriers for delivering chemotherapeutic drugs in cancer therapy and as nano-fillers to develop novel scaffolds for tissue engineering in regenerative medicine were evaluated both in vitro and in vivo. Overall, the results obtained from the present study suggest the great potential of the INPs to be used as biocompatible nanomaterials in nanomedicine. This study may open a totally new frontier for exploring the biomedical application of naturally occurring nanomaterials.

Diameter-dependent release of a cisplatin pro-drug from small and large functionalized carbon nanotubes.

The use of platinum-based chemotherapeutic drugs in cancer therapy still suffers from severe disadvantages, such as lack of appropriate selectivity for tumor tissues and insurgence of multi-drug resistance. Moreover, drug efficacy can be attenuated by several mechanisms such as premature drug inactivation, reduced drug uptake inside cells and increased drug efflux once internalized. The use of functionalized carbon nanotubes (CNTs) as chemotherapeutic drug delivery systems is a promising strategy to overcome such limitations due to their ability to enhance cellular internalization of poorly permeable drugs and thus increase the drug bioavailability at the diseased site, compared to the free drug. Furthermore, the possibility to encapsulate agents in the nanotubes' inner cavity can protect the drug from early inactivation and their external functionalizable surface is useful for selective targeting. In this study, a hydrophobic platinum(IV) complex was encapsulated within the inner space of two different diameter functionalized multi-walled CNTs (Pt(IV)@CNTs). The behavior of the complexes, compared to the free drug, was investigated on both HeLa human cancer cells and RAW 264.7 murine macrophages. Both CNT samples efficiently induced cell death in HeLa cancer cells 72 hours after the end of exposure to CNTs. Although the larger diameter CNTs were more cytotoxic on HeLa cells compared to both the free drug and the smaller diameter nanotubes, the latter allowed a prolonged release of the encapsulated drug, thus increasing its anticancer efficacy. In contrast, both Pt(IV)@CNT constructs were poorly cytotoxic on macrophages and induced negligible cell activation and no pro-inflammatory cytokine production. Both CNT samples were efficiently internalized by the two types of cells, as demonstrated by transmission electron microscopy observations and flow cytometry analysis. Finally, the platinum levels found in the cells after Pt(IV)@CNT exposure demonstrate that they can promote drug accumulation inside cells in comparison with treatment with the free complex. To conclude, our study shows that CNTs are promising nanocarriers to improve the accumulation of a chemotherapeutic drug and its slow release inside tumor cells, by tuning the CNT diameter, without inducing a high inflammatory response.

Biomarker-Guided Repurposing of Chemotherapeutic Drugs for Cancer Therapy: A Novel Strategy in Drug Development

Cancer is a leading cause of mortality worldwide and matters are only set to worsen as its incidence continues to rise. Traditional approaches to combat cancer include improved prevention, early diagnosis, optimized surgery, development of novel drugs, and honing regimens of existing anti-cancer drugs. Although discovery and development of novel and effective anti-cancer drugs is a major research area, it is well known that oncology drug development is a lengthy process, extremely costly and with high attrition rates. Furthermore, those drugs that do make it through the drug development mill are often quite expensive, laden with severe side-effects and unfortunately, to date, have only demonstrated minimal increases in overall survival. Therefore, a strong interest has emerged to identify approved non-cancer drugs that possess anti-cancer activity, thus shortcutting the development process. This research strategy is commonly known as drug repurposing or drug repositioning and provides a faster path to the clinics. We have developed and implemented a modification of the standard drug repurposing strategy that we review here; rather than investigating target-promiscuous non-cancer drugs for possible anti-cancer activity, we focus on the discovery of novel cancer indications for already approved chemotherapeutic anti-cancer drugs. Clinical implementation of this strategy is normally commenced at clinical phase II trials and includes pre-treated patients. As the response rates to any non-standard chemotherapeutic drug will be relatively low in such a patient cohort it is a pre-requisite that such testing is based on predictive biomarkers. This review describes our strategy of biomarker-guided repurposing of chemotherapeutic drugs for cancer therapy, taking the repurposing of topoisomerase I (Top1) inhibitors and Top1 as a potential predictive biomarker as case in point.

Reduction-responsive cross-linked micelles based on PEGylated polypeptides prepared via click chemistry

This study aims to develop novel reduction-responsive cross-linked micelles (CMs) based on poly(ethylene glycol)-block-poly(γ-propargyl-L-glutamate) (PEG-PPLG) by click chemistry. 1H NMR spectroscopy, IR spectroscopy, dynamic light scattering (DLS) and transmission electron microscopy (TEM) were performed to confirm the successful construction of the CMs. Doxorubicin (DOX) was loaded into the CMs as a model anticancer drug. The DOX-loaded CMs could hold the drug under physiological conditions, and release the payload quickly in the presence of glutathione (GSH). Confocal laser scanning microscopy (CLSM) and flow cytometry measurements revealed that the intracellular drug release from the DOX-loaded CMs was increased in the HeLa cells with an enhanced intracellular GSH level. In vitro methyl thiazolyl tetrazolium (MTT) assays indicated that the CMs were biocompatible, and DOX-loaded CMs showed higher cellular proliferation inhibition towards GSH-pretreated HeLa cells than non-pretreated cells. Due to their unique responsiveness, the biocompatible CMs show promise for the intracellular delivery of chemotherapeutic drugs in cancer therapy.

Phorbol esters from Jatropha meal triggered apoptosis, activated PKC-δ, caspase-3 proteins and down-regulated the proto-oncogenes in MCF-7 and HeLa cancer cell lines.

Jatropha meal produced from the kernel of Jatropha curcas Linn. grown in Malaysia contains phorbol esters (PEs). The potential benefits of PEs present in the meal as anticancer agent are still not well understood. Hence, this study was conducted to evaluate the cytotoxic effects and mode of actions of PEs isolated from Jatropha meal against breast (MCF-7) and cervical (HeLa) cancer cell lines. Isolated PEs inhibited cells proliferation in a dose-dependent manner of both MCF-7 and HeLa cell lines with the IC50 of 128.6 ± 2.51 and 133.0 ± 1.96 µg PMA equivalents/mL respectively, while the values for the phorbol 12-myristate 13-acetate (PMA) as positive control were 114.7 ± 1.73 and 119.6 ± 3.73 µg/mL, respectively. Microscopic examination showed significant morphological changes that resemble apoptosis in both cell lines when treated with PEs and PMA at IC50 concentration after 24 h. Flow cytometry analysis and DNA fragmentation results confirmed the apoptosis induction of PEs and PMA in both cell lines. The PEs isolated from Jatropha meal activated the PKC-δ and down-regulated the proto-oncogenes (c-Myc, c-Fos and c-Jun). These changes probably led to the activation of Caspase-3 protein and apoptosis cell death occurred in MCF-7 and HeLa cell lines upon 24 h treatment with PEs and PMA. Phorbol esters of Jatropha meal were found to be promising as an alternative to replace the chemotherapeutic drugs for cancer therapy.

Cisplatin@US-tube carbon nanocapsules for enhanced chemotherapeutic delivery

The use of chemotherapeutic drugs in cancer therapy is often limited by problems with administration such as insolubility, inefficient biodistribution, lack of selectivity, and inability of the drug to cross cellular barriers. To overcome these limitations, various types of drug delivery systems have been explored, and recently, carbon nanotube (CNT) materials have also garnered attention in the area of drug delivery. In this study, we describe the preparation, characterization, and in vitro testing of a new ultra-short single-walled carbon nanotube (US-tube)-based drug delivery system for the treatment of cancer. In particular, the encapsulation of cisplatin (CDDP), a widely-used anticancer drug, within US-tubes has been achieved, and the resulting CDDP@US-tube material characterized by high-resolution transmission electron microscopy (HR-TEM), energy-dispersive spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), and inductively-coupled optical emission spectrometry (ICP-OES). Dialysis studies performed in phosphate-buffered saline (PBS) at 37 °C have demonstrated that CDDP release from CDDP@US-tubes can be controlled (retarded) by wrapping the CDDP@US-tubes with Pluronic-F108 surfactant. Finally, the anticancer activity of pluronic-wrapped CDDP@US-tubes has been evaluated against two different breast cancer cell lines, MCF-7 and MDA-MB-231, and found to exhibit enhanced cytotoxicity over free CDDP after 24 h. These studies have laid the foundation for developing US-tube-based delivery of chemotherapeutics, with drug release mainly limited to within cancer cells only.