Doxorubicin and anti-VEGF siRNA co-delivery via nano-graphene oxide for enhanced cancer therapy in vitro and in vivo

The advancement of siRNA-based nanomedicine for tumor therapy

Small interfering RNA (siRNA) has been proved to be able to effectively down-regulate gene expression through the RNAi mechanism. Thus, siRNA-based drugs have become one of the hottest research directions due to their high efficiency and specificity. However, challenges such as instability, off-target effects and immune activation hinder their clinical application. This review explores the mechanisms of siRNA and the challenges in siRNA-based tumor therapy. It highlights the use of various nanomaterials - including lipid nanoparticles, polymeric nanoparticles and inorganic nanoparticles - as carriers for siRNA delivery in different therapeutic modalities. The application strategies of siRNA-based nanomedicine in chemotherapy, phototherapy and immunotherapy are discussed in detail, along with recent clinical advancements. Aiming to provide insights for future research and therapeutic approaches.

Graphene Oxide Nanoparticles and Organoids: A Prospective Advanced Model for Pancreatic Cancer Research

Pancreatic cancer, notorious for its grim 10% five-year survival rate, poses significant clinical challenges, largely due to late-stage diagnosis and limited therapeutic options. This review delves into the generation of organoids, including those derived from resected tissues, biopsies, pluripotent stem cells, and adult stem cells, as well as the advancements in 3D printing. It explores the complexities of the tumor microenvironment, emphasizing culture media, the integration of non-neoplastic cells, and angiogenesis. Additionally, the review examines the multifaceted properties of graphene oxide (GO), such as its mechanical, thermal, electrical, chemical, and optical attributes, and their implications in cancer diagnostics and therapeutics. GO's unique properties facilitate its interaction with tumors, allowing targeted drug delivery and enhanced imaging for early detection and treatment. The integration of GO with 3D cultured organoid systems, particularly in pancreatic cancer research, is critically analyzed, highlighting current limitations and future potential. This innovative approach has the promise to transform personalized medicine, improve drug screening efficiency, and aid biomarker discovery in this aggressive disease. Through this review, we offer a balanced perspective on the advancements and future prospects in pancreatic cancer research, harnessing the potential of organoids and GO.

Graphene oxide nanoarchitectures in cancer therapy: Drug and gene delivery, phototherapy, immunotherapy, and vaccine development

The latest advancements in oncology involves the creation of multifunctional nanostructures. The integration of nanoparticles into the realm of cancer therapy has brought about a transformative shift, revolutionizing the approach to addressing existing challenges and limitations in tumor elimination. This is particularly crucial in combating the emergence of resistance, which has significantly undermined the effectiveness of treatments like chemotherapy and radiotherapy. GO stands as a carbon-derived nanoparticle that is increasingly finding utility across diverse domains, notably in the realm of biomedicine. The utilization of GO nanostructures holds promise in the arena of oncology, enabling precise transportation of drugs and genetic material to targeted sites. GO nanomaterials offer the opportunity to enhance the pharmacokinetic behavior and bioavailability of drugs, with documented instances of these nanocarriers elevating drug accumulation at the tumor location. The GO nanostructures encapsulate genes, shielding them from degradation and facilitating their uptake within cancer cells, thereby promoting efficient gene silencing. The capability of GO to facilitate phototherapy has led to notable advancements in reducing tumor progression. By PDT and PTT combination, GO nanomaterials hold the capacity to diminish tumorigenesis. GO nanomaterials have the potential to trigger both cellular and innate immunity, making them promising contenders for vaccine development. Additionally, types of GO nanoparticles that respond to specific stimuli have been applied in cancer eradication, as well as for the purpose of cancer detection and biomarker diagnosis. Endocytosis serves as the mechanism through which GO nanomaterials are internalized. Given these advantages, the utilization of GO nanomaterials for tumor elimination comes highly recommended.

Framework Nucleic Acid-Based Multifunctional Tumor Theranostic Nanosystem for miRNA Fluorescence Imaging and Chemo/Gene Therapy

Intelligent stimulus-responsive theranostic systems capable of specifically sensing low-abundance tumor-related biomarkers and efficiently killing tumors remain a pressing endeavor. Here, we report a multifunctional framework nucleic acid (FNA) nanosystem for simultaneous imaging of microRNA-21 (miR-21) and combined chemo/gene therapy. To achieve this, two FNA nanoarchitectures labeled with Cy5/BHQ2 signal tags were designed, each of which contained an AS1411 aptamer, two pairs of DNA/RNA hybrids, a pH-sensitive DNA catcher, and doxorubicin (DOX) intercalating between cytosine and guanine in the tetrahedral DNA nanostructure (TDN). In the acidic tumor microenvironment, the DNA catchers spontaneously triggered to form an i-motif and create an FNA dimer (dFNA) while releasing DOX molecules to exert a cytotoxic effect. In addition, the overexpressed miR-21 in tumor cells dismantled the DNA/RNA hybrids to produce vascular endothelial growth factor-associated siRNA via a toehold-mediated strand displacement reaction, thus enabling a potent RNA interfering. Also importantly, the liberated miR-21 could initiate cascade-reaction amplification to efficiently activate the Cy5 signal reporters, thereby realizing on-site fluorescence imaging of miR-21 in living cells. The exquisitely designed FNA-based nanosystem showed favorable biocompatibility and stability as well as acid-driven DOX release characteristics. Owing to the aptamer-guided targeting delivery, specific uptake of the FNA-based theranostic nanosystem by HepG2 cells was verified with confocal laser scanning microscopy and flow cytometry analyses, which therefore resulted in apoptosis of HepG2 cells while doing minimal damage to normal H9c2 and HL-7702 cells. Strikingly, both in vitro and in vivo experiments demonstrated the achievements of the FNA-enabled miR-21 imaging and synergistically enhanced chemo/gene therapy. This work thus represents a noteworthy advance on the FNA-based theranostic strategy that can effectively avoid the undesirable premature leakage of anticarcinogen and off-target of siRNA, and achieve on-demand reagents release for tumor diagnostics and treatment.

Graphene family in cancer therapy: recent progress in cancer gene/drug delivery applications

In the past few years, the development in the construction and architecture of graphene based nanocomplexes has dramatically accelerated the use of nano-graphene for therapeutic and diagnostic purposes, fostering a new area of nano-cancer therapy. To be specific, nano-graphene is increasingly used in cancer therapy, where diagnosis and treatment are coupled to deal with the clinical difficulties and challenges of this lethal disease. As a distinct family of nanomaterials, graphene derivatives exhibit outstanding structural, mechanical, electrical, optical, and thermal capabilities. Concurrently, they can transport a wide variety of synthetic agents, including medicines and biomolecules, such as nucleic acid sequences (DNA and RNA). Herewith, we first provide an overview of the most effective functionalizing agents for graphene derivatives and afterward discuss the significant improvements in the gene and drug delivery composites based on graphene.

Magnetically responsive nanoplatform targeting circRNA circ_0058051 inhibits hepatocellular carcinoma progression

Circular RNAs (circRNAs) are a class of highly stable and closed-loop noncoding RNA that are involved in the occurrence and development of hepatocellular carcinoma (HCC). However, little is known about the therapeutic role of circRNAs in HCC. We found that high circ_0058051 expression was negatively correlated with the prognosis of HCC patients. Circ_0058051 knockdown attenuated the proliferation and colony formation, meanwhile inhibited migration of HCC cells. Circ_0058051 may be used as a target for HCC gene therapy. We synthesized a novel small interfering RNA (siRNA) delivery system, PEG-PCL-PEI-C14-SPIONs (PPPCSs), based on superparamagnetic iron oxide nanoparticles (SPIONs). PPPCSs protected the siRNA of circ_0058051 from degradation in serum and effectively delivered siRNA into SMMC-7721 cells. Meanwhile, intravenous injection of the PPPCSs/siRNA complex could inhibit tumor growth in the subcutaneous tumor model. In addition, the nanocomposite is not toxic to the organs of nude mice. The above results show that PPPCSs/si-circ_0058051 complex may provide a novel and promising method of HCC treatment.

Graphene oxide nanoarchitectures in cancer biology: Nano-modulators of autophagy and apoptosis

Nanotechnology is a growing field, with many potential biomedical applications of nanomedicine for the treatment of different diseases, particularly cancer, on the horizon. Graphene oxide (GO) nanoparticles can act as carbon-based nanocarriers with advantages such as a large surface area, good mechanical strength, and the capacity for surface modification. These nanostructures have been extensively used in cancer therapy for drug and gene delivery, photothermal therapy, overcoming chemotherapy resistance, and for imaging procedures. In the current review, we focus on the biological functions of GO nanoparticles as regulators of apoptosis and autophagy, the two major forms of programmed cell death. GO nanoparticles can either induce or inhibit autophagy in cancer cells, depending on the conditions. By stimulating autophagy, GO nanocarriers can promote the sensitivity of cancer cells to chemotherapy. However, by impairing autophagy flux, GO nanoparticles can reduce cell survival and enhance inflammation. Similarly, GO nanomaterials can increase ROS production and induce DNA damage, thereby sensitizing cancer cells to apoptosis. In vitro and in vivo experiments have investigated whether GO nanomaterials show any toxicity in major body organs, such as the brain, liver, spleen, and heart. Molecular pathways, such as ATG, MAPK, JNK, and Akt, can be regulated by GO nanomaterials, leading to effects on autophagy and apoptosis. These topics are discussed in this review to shed some lights towards the biomedical potential of GO nanoparticles and their biocompatibility, paving the way for their future application in clinical trials.

Elimination of Cancer Cells in Co-Culture: Role of Different Nanocarriers in Regulation of CD47 and Calreticulin-Induced Phagocytosis

Under healthy conditions, pro- and anti-phagocytic signals are balanced. Cluster of Differentiation 47 (CD47) is believed to act as an anti-phagocytic marker that is highly expressed on multiple types of human cancer cells including acute myeloid leukemia (AML) and lung and liver carcinomas, allowing them to escape phagocytosis by macrophages. Downregulating CD47 on cancer cells discloses calreticulin (CRT) to macrophages and recovers their phagocytic activity. Herein, we postulate that using a modified graphene oxide (GO) carrier to deliver small interfering RNA (siRNA) CD47 (CD47_siRNA) in AML, A549 lung, and HepG2 liver cancer cells in co-culture in vitro will silence CD47 and flag cancer cells for CRT-mediated phagocytosis. Results showed a high knockdown efficiency of CD47 and a significant increase in CRT levels simultaneously by using GO formulation as carriers in all used cancer cell lines. The presence of CRT on cancer cells was significantly higher than levels before knockdown of CD47 and was required to achieve phagocytosis in co-culture with human macrophages. Lipid nanoparticles (LNPs) and modified boron nitride nanotubes (BNPs) were used to carry CD47_siRNA, and the knockdown efficiency values of CD47 were compared in three cancer cells in co-culture, with an achieved knockdown efficiency of >95% using LNPs as carriers. Interestingly, the high efficiency of CD47 knockdown was obtained by using the LNPs and BNP carriers; however, an increase in CRT levels on cancer cells was not required for phagocytosis to happen in co-culture with human macrophages, indicating other pathways' involvement in the phagocytosis process. These findings highlight the roles of 2D (graphene oxide), 1D (boron nitride nanotube), and "0D" (lipid nanoparticle) carriers for the delivery of siRNA to eliminate cancer cells in co-culture, likely through different phagocytosis pathways in multiple types of human cancer cells. Moreover, these results provide an explanation of immune therapies that target CD47 and the potential use of these carriers in screening drugs for such therapies in vitro.

Advanced strategies for nucleic acids and small-molecular drugs in combined anticancer therapy

Cancer has been considered as complex malignant consequence of genetic mutations that control the cellular proliferation, differentiation and homeostasis, thus making tumor treatment extremely challenging. To date, a variety of cargo molecules, including nucleic acids drugs (pDNA, miRNA and siRNA), therapeutic drugs (doxorubicin, paclitaxel, daunomycin and gefitinib) and imaging agents (radioisotopes, fluorescence dyes, and MRI contrast agents) have been regarded as the potential medicines in clinical application. However, non-single therapeutic drug could induce the satisfied clinical results because of tumor heterogeneity and multiple drug resistance and the nanotechnology-based combined therapy is becoming an advanced important mode for enhanced anticancer effects. The review gathers the current advanced development to co-deliver small-molecular drugs and nucleic acids for the anticancer therapy with nanomedicine-based combination. Furthermore, the superiority is definitely presented and the barriers are detail discussed to surmount the clinical challenges. In final, future perspectives in rational direction for combined tumor therapy of drugs and nucleic acids are exhibited.

In vivo study of anticancer activity of ginsenoside Rh2-containing arginine-reduced graphene in a mouse model of breast cancer

Objectives

This study aims to evaluate the in vivo anticancer activity of arginine-reduced graphene (Gr-Arg) and ginsenoside Rh2-containing arginine-reduced graphene (Gr-Arg-Rh2).

Materials and Methods

Thirty-two mice with breast cancer were divided into four groups and treated every three days for 32 days: Group 1, PBS, Group 2, Rh2, Group 3, Gr-Arg, and Group 4, Gr-Arg-Rh2. The tumor size and weight, gene expression (IL10, INF-γ, TGFβ, and FOXP3), and pathological properties of the tumor and normal tissues were assessed.

Results

Results showed a significant decrease in TGFβ expression for all drug treatment groups compared with the controls (P=0.04). There was no significant difference among the groups regarding IL10 and FOXP3 gene expression profiles (P>0.05). Gr-Arg-Rh2 significantly inhibited tumor growth (size and weight) compared with Rh2 and control groups. The highest survival rate and the highest percentage of tumor necrosis (87.5%) belonged to the Gr-Arg-Rh2 group. Lungs showed metastasis in the control group. No metastasis was observed in the Gr-Arg-Rh2 group. Gr-Arg-Rh2 showed partial degeneration of hepatocytes and acute cell infiltration in the portal spaces and around the central vein. The Gr-Arg group experienced a moderate infiltration of acute cells into the port spaces and around the central vein. The Rh2 group also showed a mild infiltration of acute and chronic cells in portal spaces.

Conclusion

Based on the results, Gr-Arg-Rh2 can reduce tumor size, weight, and growth, TGF-β gene expression, and increase tumor necrosis and survival time in mice with cancer.

Recent Trends in Nanomedicine-Based Strategies to Overcome Multidrug Resistance in Tumors

Cancer is the leading cause of economic and health burden worldwide. The commonly used approaches for the treatment of cancer are chemotherapy, radiotherapy, and surgery. Chemotherapy frequently results in undesirable side effects, and cancer cells may develop resistance. Combating drug resistance is a challenging task in cancer treatment. Drug resistance may be intrinsic or acquired and can be due to genetic factors, growth factors, the increased efflux of drugs, DNA repair, and the metabolism of xenobiotics. The strategies used to combat drug resistance include the nanomedicine-based targeted delivery of drugs and genes using different nanocarriers such as gold nanoparticles, peptide-modified nanoparticles, as well as biomimetic and responsive nanoparticles that help to deliver payload at targeted tumor sites and overcome resistance. Gene therapy in combination with chemotherapy aids in this respect. siRNA and miRNA alone or in combination with chemotherapy improve therapeutic response in tumor cells. Some natural substances, such as curcumin, quercetin, tocotrienol, parthenolide, naringin, and cyclosporin-A are also helpful in combating the drug resistance of cancer cells. This manuscript summarizes the mechanism of drug resistance and nanoparticle-based strategies used to combat it.

Carbon-based Nanomaterials for delivery of small RNA molecules: a focus on potential cancer treatment applications

BACKGROUND

Nucleic acid-mediated therapy holds immense potential in the treatment of recalcitrant human diseases such as cancer. This is underscored by advances in understanding the mechanisms of gene regulation. In particular, the endogenous protective mechanism of gene silencing known as RNA interference (RNAi) has been extensively exploited.

METHODS

We review here the developments from 2011 to 2021, in the use of nanographene oxide, carbon nanotubes, fullerenes, carbon nanohorns, carbon nanodots and nanodiamonds for the delivery of therapeutic small RNA molecules.

RESULTS

Appropriately designed effector molecules such as small interfering RNA (siRNA), can, in theory, silence the expression of any disease-causing gene. Alternatively, siRNA can be generated in vivo through the introduction of plasmid-based short hairpin RNA (shRNA) expression vectors. Other small RNAs such as micro RNA (miRNA) also function in post-transcriptional gene regulation and are aberrantly expressed under disease conditions. The miRNA-based therapy involves either restoration of miRNA function through the introduction of miRNA mimics; or the inhibition of miRNA function by delivering anti-miRNA oligomers. However, the large size, hydrophilicity, negative charge and nuclease-sensitivity of nucleic acids necessitate an appropriate carrier for their introduction as medicine into cells.

CONCLUSION

While numerous organic and inorganic materials have been investigated for this purpose, the perfect carrier agent remains elusive. In recent years, carbon-based nanomaterials have received widespread attention in biotechnology due to their tunable surface characteristics, mechanical, electrical, optical and chemical properties.

Engineering a multi-target therapy nanoplatform against tumor growth and metastasis via a novel NSAID-Pt(IV) prodrug

Tumor growth and metastasis are caused by many factors. The complexity means that a multi-target combination therapy strategy should be selected against tumor growth and metastasis. Here, cisplatin (CDDP) and bendazac (Ben) were designed as a novel NSAID-Pt(IV) nanoplatform, which is an effective weapon for combating tumor growth and metastasis.

Graphene and graphene oxide with anticancer applications: Challenges and future perspectives

Graphene-based materials have shown immense pertinence for sensing/imaging, gene/drug delivery, cancer therapy/diagnosis, and tissue engineering/regenerative medicine. Indeed, the large surface area, ease of functionalization, high drug loading capacity, and reactive oxygen species induction potentials have rendered graphene- (G-) and graphene oxide (GO)-based (nano)structures promising candidates for cancer therapy applications. Various techniques namely liquid-phase exfoliation, Hummer's method, chemical vapor deposition, chemically reduced GO, mechanical cleavage of graphite, arc discharge of graphite, and thermal fusion have been deployed for the production of G-based materials. Additionally, important criteria such as biocompatibility, bio-toxicity, dispersibility, immunological compatibility, and inflammatory reactions of G-based structures need to be systematically assessed for additional clinical and biomedical appliances. Furthermore, surface properties (e.g., lateral dimension, charge, corona influence, surface structure, and oxygen content), concentration, detection strategies, and cell types are vital for anticancer activities of these structures. Notably, the efficient accumulation of anticancer drugs in tumor targets/tissues, controlled cellular uptake properties, tumor-targeted drug release behavior, and selective toxicity toward the cells are crucial criteria that need to be met for developing future anticancer G-based nanosystems. Herein, important challenges and future perspectives of cancer therapy using G- and GO-based nanosystems have been highlighted, and the recent advancements are deliberated.

Doxorubicin-loaded graphene oxide nanocomposites in cancer medicine: Stimuli-responsive carriers, co-delivery and suppressing resistance

INTRODUCTION

The application of doxorubicin (DOX) in cancer therapy has been limited due to its drug resistance and poor internalization. Graphene oxide (GO) nanostructures have the capacity for DOX delivery while promoting its cytotoxicity in cancer.

AREAS COVERED

The favorable characteristics of GO nanocomposites, preparation method, and application in cancer therapy are described. Then, DOX resistance in cancer is discussed. The GO-mediated photothermal therapy and DOX delivery for cancer suppression are described. Preparation of stimuli-responsive GO nanocomposites, surface functionalization, hybrid nanoparticles, and theranostic applications are emphasized in DOX chemotherapy.

EXPERT OPINION

Graphene oxide nanoparticle-based photothermal therapy maximizes the anti-cancer activity of DOX against cancer cells. Apart from DOX delivery, GO nanomaterials are capable of loading anti-cancer agents and genetic tools to minimize drug resistance and enhance the cytolytic impact of DOX in cancer eradication. To enhance DOX accumulation in cancer cells, stimuli-responsive (redox-, light-, enzyme- and pH-sensitive) GO nanoparticles have been developed for DOX delivery. Further development of targeted delivery of DOX-loaded GO nanomaterials against cancer cells may be achieved by surface modification of polymers such as polyethylene glycol, hyaluronic acid, and chitosan. Doxorubicin-loaded GO nanoparticles have demonstrated theranostic potential for simultaneous diagnosis and therapy. Hybridization of GO with other nanocarriers such as silica and gold nanoparticles further broadens their potential anti-cancer therapy applications.

Simultaneous nanocarrier-mediated delivery of siRNAs and chemotherapeutic agents in cancer therapy and diagnosis: Recent advances

Recently, investigations have revealed that RNA interference (RNAi) has a remarkable potential to decrease cancer burden by downregulating genes. Among various RNAi molecules, small interfering RNA (siRNA) has been more attractive for this goal and is able to silence a target pathological path and promote the degradation of a certain mRNA, resulting in either gain or loss of function of proteins. Moreover, therapeutic siRNAs have exhibited low side effects compared to other therapeutic molecular candidates. Nevertheless, siRNA delivery has its own limitations including quick degradation in circulation, ineffective internalization and low passive uptake by cells, possible toxicity against off-target sites, and inducing unfavorable immune responses. Therefore, delivery tools must be able to specifically direct siRNAs to their target locations without inflicting detrimental effects on other sites. To conquer the mentioned problems, nanocarrier-mediated delivery of siRNAs, using inorganic nanoparticles (NPs), polymers, and lipids, has been developed as a biocompatible delivery approach. In this review, we have discussed recent advances in the siRNA delivery methods that employ nanoparticles, lipids, and polymers, as well as the inorganic-based co-delivery systems used to deliver siRNAs and anticancer agents to target cells.

Nanocarriers for pancreatic cancer imaging, treatments, and immunotherapies

Pancreatic tumors are highly desmoplastic and immunosuppressive. Delivery and distribution of drugs within pancreatic tumors are compromised due to intrinsic physical and biochemical stresses that lead to increased interstitial fluid pressure, vascular compression, and hypoxia. Immunotherapy-based approaches, including therapeutic vaccines, immune checkpoint inhibition, CAR-T cell therapy, and adoptive T cell therapies, are challenged by an immunosuppressive tumor microenvironment. Together, extensive fibrosis and immunosuppression present major challenges to developing treatments for pancreatic cancer. In this context, nanoparticles have been extensively studied as delivery platforms and adjuvants for cancer and other disease therapies. Recent advances in nanotechnology have led to the development of multiple nanocarrier-based formulations that not only improve drug delivery but also enhance immunotherapy-based approaches for pancreatic cancer. This review discusses and critically analyzes the novel nanoscale strategies that have been used for drug delivery and immunomodulation to improve treatment efficacy, including newly emerging immunotherapy-based approaches. This review also presents important perspectives on future research directions that will guide the rational design of novel and robust nanoscale platforms to treat pancreatic tumors, particularly with respect to targeted therapies and immunotherapies. These insights will inform the next generation of clinical treatments to help patients manage this debilitating disease and enhance survival rates.

Laser activatable nanographene colloids for chemo-photothermal combined gene therapy of triple-negative breast cancer

This investigation reports the green approach for developing laser activatable nanoscale-graphene colloids (nGC-CO-FA) for chemo-photothermal combined gene therapy of triple-negative breast cancer (TNBC). The nano colloid was found to be nanometric as characterized by SEM, AFM, and zeta sizer (68.2 ± 2.1 nm; 13.8 ± 1.2 mV). The doxorubicin (Dox) loaded employing hydrophobic interaction/π-π stacking showed >80% entrapment efficiency with a sustained pH-dependent drug release profile. It can efficiently incorporate siRNA and Dox and successfully co-localize them inside TNBC cells to obtain significant anticancer activity as evaluated using CCK-8 assay, apoptosis assay, cell cycle analysis, cellular uptake, fluorescence assay, endosomal escape study, DNA content analysis, and gene silencing efficacy studies. nGC-CO-FA/Dox/siRNA released the Dox in temperature- and a pH-responsive manner following NIR-808 laser irradiation. The synergistic photo-chemo-gene therapy using near infrared-808 nm laser (NIR-808) irradiation was found to be more effective as compared to without NIR-808 laser-treated counterparts (∆T: 37 ± 1.1 °C → to 49.2 ± 3.1 °C; 10 min; 0.5 W/cm²), suggesting the pivotal role of photothermal combined gene-therapy in the treatment of TNBC.

Anti-EpCAM functionalized graphene oxide vector for tumor targeted siRNA delivery and cancer therapy

Graphene oxide (GO) has emerged as a potential drug delivery vector. For siRNA delivery, GO should be modified to endow it with gene delivery ability and targeting effect. However, the cationic materials used previously usually had greater toxicity. In this study, GO was modified with a non-toxicity cationic material (chitosan) and a tumor specific monoclonal antibody (anti-EpCAM) for the delivery of survivin-siRNA (GCE/siRNA). And the vector (GCE) prepared was proved with excellent biosafety and tumor targeting effect. The GCE exhibited superior performance in loading siRNA, maintained stability in different solutions and showed excellent protection effect for survivin-siRNA in vitro. The gene silencing results in vitro showed that the mRNA level and protein level were down-regulated by 48.24% ± 2.50% and 44.12% ± 3.03%, respectively, which was equal with positive control (P > 0.05). It was also demonstrated that GCE/siRNA had a strong antitumor effect in vitro, which was attributed to the efficient antiproliferation, and migration and invasion inhibition effect of GCE/siRNA. The results in vivo indicated that GCE could accumulate siRNA in tumor tissues. The tumor inhibition rate of GCE/siRNA 54.74% ± 5.51% was significantly higher than control 4.87% ± 8.49%. Moreover, GCE/siRNA showed no toxicity for blood and main organs, suggesting that it is a biosafety carrier for gene delivery. Taken together, this study provides a novel design strategy for gene delivery system and siRNA formulation.

Histone acetyltransferase 1 promotes gemcitabine resistance by regulating the PVT1/EZH2 complex in pancreatic cancer

The poor prognosis of pancreatic cancer is primarily due to the development of resistance to therapies, including gemcitabine. The long noncoding RNA PVT1 (lncRNA PVT1) has been shown to interact with enhancer of zeste 2 polycomb repressive complex 2 subunit (EZH2), promoting gemcitabine resistance in pancreatic cancer. In this study, we found histone acetyltransferase 1 (HAT1) enhanced the tolerance of pancreatic cancer cells to gemcitabine and HAT1-mediated resistance mechanisms were regulated by PVT1 and EZH2. Our results showed that the aberrant HAT1 expression promoted gemcitabine resistance, while silencing HAT1 restored gemcitabine sensitivity. Moreover, HAT1 depletion caused a notable increase of gemcitabine sensitivity in gemcitabine-resistant pancreatic cancer cell lines. Further research found that HAT1 increased PVT1 expression to induce gemcitabine resistance, which enhanced the binding of bromodomain containing 4 (BRD4) to the PVT1 promoter, thereby promoting PVT1 transcription. Besides, HAT1 prevented EZH2 degradation by interfering with ubiquitin protein ligase E3 component n-recognin 4 (UBR4) binding to the N-terminal domain of EZH2, thus maintaining EZH2 protein stability to elevate the level of EZH2 protein, which also promoted HAT1-mediated gemcitabine resistance. These results suggested that HAT1 induced gemcitabine resistance of pancreatic cancer cells through regulating PVT1/EZH2 complex. Given this, Chitosan (CS)-tripolyphosphate (TPP)-siHAT1 nanoparticles were developed to block HAT1 expression and improve the antitumor effect of gemcitabine. The results showed that CS-TPP-siHAT1 nanoparticles augmented the antitumor effects of gemcitabine in vitro and in vivo. In conclusion, HAT1-targeted therapy can improve observably gemcitabine sensitivity of pancreatic cancer cells. HAT1 is a promising therapeutic target for pancreatic cancer.

MicroRNA Delivery by Graphene-Based Complexes into Glioblastoma Cells

Glioblastoma (GBM) is the most common primary and aggressive tumour in brain cancer. Novel therapies, despite achievements in chemotherapy, radiation and surgical techniques, are needed to improve the treatment of GBM tumours and extend patients’ survival. Gene delivery therapy mostly uses the viral vector, which causes serious adverse events in gene therapy. Graphene-based complexes can reduce the potential side effect of viral carries, with high efficiency of microRNA (miRNA) or antisense miRNA delivery to GBM cells. The objective of this study was to use graphene-based complexes to induce deregulation of miRNA level in GBM cancer cells and to regulate the selected gene expression involved in apoptosis. The complexes were characterised by Fourier transform infrared spectroscopy (FTIR), scanning transmission electron microscopy and zeta potential. The efficiency of miRNA delivery to the cancer cells was analysed by flow cytometry. The effect of the anticancer activity of graphene-based complexes functionalised by the miRNA sequence was analysed using 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxyanilide salt (XTT) assays at the gene expression level. The results partly explain the mechanisms of miRNA deregulation stress, which is affected by graphene-based complexes together with the forced transport of mimic miR-124, miR-137 and antisense miR-21, -221 and -222 as an anticancer supportive therapy.

Nanotechnology lights up the antitumor potency by combining chemotherapy with siRNA

Nanotechnology-based combination anticancer therapy offers novel approaches to overcome the limitations of single-agent administration. The emerging siRNA technology combined with chemotherapy has shown considerable promise in anticancer therapy. There are three main challenges in the fabrication of siRNA/chemotherapeutic drug co-loaded nanovectors: adequate cargo protection, precise targeted delivery, and site-specific cargo release. This review presents a summary of the nanosystems that have recently been developed for co-delivering siRNA and chemotherapeutic drugs. Their combined therapeutic effects are also discussed.

Fluorescence "turn-off/turn-on" biosensing of metal ions by gold nanoclusters, folic acid and reduced graphene oxide

Metal ions homeostasis plays an important role in biological processes. The ability to detect the concentration of metal ions in biological fluids is often challenged by the obvious interference or competitive binding nature of other alkaline metals ions. Common analytical techniques employed for metal ions detection are electrochemical, fluorescence and colorimetric methods. However, most reported metal ions sensors are complicated, time-consuming and involve costly procedures with limited effectiveness. Herein, a nanobiosensor for detecting sodium and potassium ions using folic acid-functionalised reduced graphene oxide-modified RNase A gold nanoclusters (FA-rGO-RNase A/AuNCs) based on fluorescence "turn-off/turn-on" is presented. Firstly, a facile and optimised protocol for the fabrication of RNase A/AuNCs is developed. The activity of RNase A protein after the formation of RNase A/AuNCs is studied. RNase A/AuNCs is then loaded onto FA-rGO, in which FA-rGO is used as a potential carrier and fluorescence quencher for RNase A/AuNCs. Finally, a fluorescence "turn-on" sensing strategy is developed using the as-synthesised FA-rGO-RNase A/AuNCs to detect sodium and potassium ions. The developed nanobiosensor revealed an excellent sensing performance and meets the sensitivity required to detect both sodium and potassium ions. To the best of our knowledge, this is the first work done on determining the RNase A protein activity in RNase A/AuNCs and exploring the potential application of RNase A/AuNCs as a metal ion sensor. This work serves as a proof-of-concept for combining the potential of drug delivery, active targeting and therapy on cancer cells, as well as biosensing of metal ions into a single platform.

Tumor microenvironment remodeling-based penetration strategies to amplify nanodrug accessibility to tumor parenchyma

Remarkable advances in nano delivery systems have provided new hope for tumor prevention, diagnosis and treatment. However, only limited clinical therapeutic effects against solid tumors were achieved. One of the main reasons is the presence of abundant physiological and pathological barriers in vivo that impair tumoral penetration and distribution of the nanodrugs. These barriers are related to the components of tumor microenvironment (TME) including abnormal tumor vasculature, rich composition of the extracellular matrix (ECM), and abundant stroma cells. Herein, we review the advanced strategies of TME remodeling to overcome these biological obstacles against nanodrug delivery. This review aims to offer a perspective guideline for the implementation of promising approaches to facilitate intratumoral permeation of nanodrugs through alleviation of biological barriers. At the same time, we analyze the advantages and disadvantages of the corresponding methods and put forward possible directions for the future researches.

Preparation Optimization of Bovine Serum Albumin Nanoparticles and Its Application for siRNA Delivery

BACKGROUND

siRNA brings hope for cancer therapy. However, there are many obstacles for application of siRNA in clinical. Because of the excellent biocompatibility, non-toxicity and non-immunogenicity of bovine serum albumin (BSA), BSA-based nanoparticles have been widely designed as a drug carrier system.

METHODS

The optimal formula for BSA NPs preparation was investigated by central composite design response surface methodology (CCD-RSM), BSA-based survivin-siRNA delivery system (BSA NPs/siRNA) was characterized by dynamic light scattering, atomic force microscope, transmission electron microscope and Bradford method. The in vitro anti-tumor effect and mechanism of BSA NPs were investigated by confocal microscopic imaging, MTT assay, RT-qPCR and ELISA analysis. Moreover, the anti-tumor effect, distribution and biosafety of BSA NPs were studied in vivo.

RESULTS

The optimal formula for BSA NPs was settled to be 20 mg/mL for BSA concentration, 9 for pH value, 136% for crosslinking degree and 1.6 mL/min for speed of ethanol addition. BSA NPs/siRNA could remain stable at 4°C for 4 weeks and protect siRNA from degradation by RNase A. Besides, BSA NPs/siRNA could maintain a sustained release of siRNA and promote the uptake of siRNA significantly. The survivin-mRNA level and the survivin-protein level were decreased by 55% ± 1.6% and 54% ± 1.6% separately. The in vivo tumor inhibition results suggested that the tumor inhibition rate of BSA NPs/siRNA-treated group was 54% ± 12% and was similar with that of DOX-treated group (57% ± 9.2%, P > 0.05). The biosafety results confirmed that BSA NPs/siRNA could not induce significant damages to the main organs and blood in vivo.

CONCLUSION

These results demonstrated that CCD-RSM was an effective tool for preparation analysis, and the BSA NPs/siRNA was a promising system for siRNA-based gene therapy.

The importance of co-delivery of nanoparticle-siRNA and anticancer agents in cancer therapy

According to global statistics, cancer is the second leading cause of death worldwide. Because of the heterogeneity of cancer, single-drug therapy has many limitations due to low efficacy. Therefore, combination therapy with two or more therapeutic agents is being arisen. One of the most important approaches in cancer therapy is the shot down of key genes involved in apoptotic processes and cell cycle. In this regard, siRNA is a good candidate, a highly attractive method to suppressing tumor growth and invasion. Combination therapy with siRNAs and chemotherapeutic agents can overcome the multidrug resistance and increase apoptosis. The efficient delivery of siRNA to the target cell/tissue/organ has been a challenge. To overcome these challenges, the presence of suitable delivery systems by using nanoparticles is interesting. In this review, we discuss the current challenges for successful RNA interference. Also, we suggested proper a strategy for delivering siRNA that can be useful in targeting therapy. Finally, the combination of a variety of anticancer drugs and siRNA through acceptable delivery systems and their effects on cell cycle and apoptosis will be evaluated.

Carbon-based nanomaterials for targeted cancer nanotherapy: recent trends and future prospects

Carbon-based nanomaterials are becoming attractive materials due to their unique structural dimensions and promising mechanical, electrical, thermal, optical and chemical characteristics. Carbon nanotubes, graphene, graphene oxide, carbon and graphene quantum dots have numerous applications in diverse areas, including biosensing, drug/gene delivery, tissue engineering, imaging, regenerative medicine, diagnosis, and cancer therapy. Cancer remains one of the major health problems all over the world, and several therapeutic approaches are focussed on designing targeted anticancer drug delivery nanosystems by applying benign and less hazardous resources with high biocompatibility, ease of functionalization, remarkable targeted therapy issues, and low adverse effects. This review highlights the recent development on these carbon based-nanomaterials in the field of targeted cancer therapy and discusses their possible and promising diagnostic and therapeutic applications for the treatment of cancers.

Recent advances in graphene-family nanomaterials for effective drug delivery and phototherapy

INTRODUCTION

Owing to the unique properties of graphene, including large specific surface area, excellent thermal conductivity, and optical absorption, graphene-family nanomaterials (GFNs) have attracted extensive attention in biomedical applications, particularly in drug delivery and phototherapy.

AREAS COVERED

In this review, we point out several challenges involved in the clinical application of GFNs. Then, we provide an overview of the most recent publications about GFNs in biomedical applications, including diverse strategies for improving the biocompatibility, specific targeting and stimuli-responsiveness of GFNs for drug delivery, codelivery of drug and gene, photothermal therapy, photodynamic therapy, and multimodal combination therapy.

EXPERT OPINION

Although the application of GFNs is still in the preclinical stage, rational modification of GFNs with functional elements or making full use of GFNs-based multimodal combination therapy might show great potential in biomedicine for clinical application.

Progress in Natural Compounds/siRNA Co-delivery Employing Nanovehicles for Cancer Therapy

Chemotherapy using natural compounds, such as resveratrol, curcumin, paclitaxel, docetaxel, etoposide, doxorubicin, and camptothecin, is of importance in cancer therapy because of the outstanding therapeutic activity and multitargeting capability of these compounds. However, poor solubility and bioavailability of natural compounds have limited their efficacy in cancer therapy. To circumvent this hurdle, nanocarriers have been designed to improve the antitumor activity of the aforementioned compounds. Nevertheless, cancer treatment is still a challenge, demanding novel strategies. It is well-known that a combination of natural products and gene therapy is advantageous over monotherapy. Delivery of multiple therapeutic agents/small interfering RNA (siRNA) as a potent gene-editing tool in cancer therapy can maximize the synergistic effects against tumor cells. In the present review, co-delivery of natural compounds/siRNA using nanovehicles are highlighted to provide a backdrop for future research.

Virus Mimetic Shell-Sheddable Chitosan Micelles for siVEGF Delivery and FRET-Traceable Acid-Triggered Release

Targeting vascular endothelial growth factor (VEGF) using small interfering RNA (siVEGF) has shown great potential in inhibiting the growth, proliferation, and migration of tumors by reducing the proliferation of blood vessels. On the basis of bionic principles, a novel pH-responsive and virus mimetic shell-sheddable chitosan (CS) micelles (CMs) as siRNA delivery system was introduced in this study. The cyclo(Arg-Gly-Asp-d-Phe-Lys) (cRGD) modified poly(enthylene glycol) (PEG) was conjugated to the HA2 modified chitosan via a hydrazone linkage (cRGD-PEG-Hz-CS-HA2). The cRGD-PEG-Hz-CS-HA2 conjugate could form micelles by interacting with the complex of octanal, Boc-l-lysine, and 9-d-arginine (9R) (octyl-Lys-9R) as a hydrophodic core forming agent, termed as cRGD-PEG-Hz-CS-HA2/octyl-Lys-9R (abbreviated as cRGD/HA2/Hz-CMs).The CMs modified with cRGD can accurately target glioma cells (U87MG cells) with high expression of αvβ3. The payloads of siVEGF were packed into the core of cRGD/HA2/Hz-CMs via electrostatic interaction and hydrophobic interaction. The intracellular cargo release was achieved by the pH-responsive lysis of the hydrazone bond in acidic environment of endosome. Moreover, the exposed HA2, as a pH-sensitive membrane-disruptive peptide, assists the escape of the carriers from endosome into cytosol. In addition, cRGD/HA2/Hz-CMs can effectively deliver siVEGF and silence VEGF gene expression in U87MG cells, leading to the significant tumor growth inhibition. This study demonstrates that cRGD/HA2/Hz-CMs can deliver and release siVEGF in a controlled manner, which was traced by the fluorescence resonance energy transfer (FRET) system in order to achieve RNAi-based anti-angiogenic treatment of cancer in vivo.

Graphene Oxide Ameliorates the Cognitive Impairment Through Inhibiting PI3K/Akt/mTOR Pathway to Induce Autophagy in AD Mouse Model

Alzheimer's disease (AD) is a neurodegenerative disease of the central nervous system characterised by cognitive impairment. Its major pathological feature is the deposition of β-amyloid (Aβ) peptide, which triggers a series of pathological cascades. Autophagy is a main pathway to eliminate abnormal aggregated proteins, and increasing autophagy represents a plausible treatment strategy against relative overproduction of neurotoxic Aβ. Graphene oxide (GO) is an emerging carbon-based nanomaterial. As a derivative of graphene with neuroprotective effects, it can effectively increase the clearance of abnormally aggregated protein. In this article, we investigated the protective function of GO in an AD mouse model. GO (30 mg/kg, intraperitoneal) was administered for 2 weeks. The results of the Morris water maze test and the novel object recognition test suggested that GO ameliorated learning and memory impairments in 5xFAD mice. The long-term potentiation and depotentiation from the perforant path to the dentate gyrus in the hippocampus were increased with GO treatment in 5xFAD mice. Furthermore, GO upregulated the expression of synapse-related proteins and increased the cell density in the hippocampus. Our results showed that GO up-regulated LC3II/LC3I and Beclin-1 and decreased p62 protein levels in 5xFAD mice. In addition, GO downregulated the PI3K/Akt/mTOR signalling pathway to induce autophagy. These results have revealed the protective potential of GO in AD.

A non-viral nano-delivery system targeting epigenetic methyltransferase EZH2 for precise acute myeloid leukemia therapy

Acute myeloid leukemia (AML), which is common in the elderly population, accounts for poor long-term survival with a high possibility of relapse. The associated lack of currently developed therapeutics is directing the search for new therapeutic targets relating to AML. EZH2 (Enhancer of Zeste Homolog 2) is a histone methyltransferase member of the polycomb-group (PcG) family, and its significant overexpression in AML means it has emerged as a potential epigenetic target. Here, we propose the human serum albumin (HSA) nanoparticle based delivery of small interfering RNA (siRNA), which can target EZH2-expressing genes in AML. EZH2 specific siRNA loaded in a polyethyleneimine (PEI) conjugated HSA nanocarrier can overcome the systemic instability of siRNA and precisely target the AML cell population for increased EZH2 gene silencing. A stable nanosized complex (HSANPs-PEI@EZH2siRNA), achieved via the electrostatic interaction of PEI and EZH2 siRNA, shows increased systemic stability and hemocompatibility, and enhanced EZH2 gene silencing activity in vitro, compared to conventional transfection reagents. HSANPs-PEI@EZH2siRNA-treated AML cells showed downregulated EZH2, which is associated with a reduced level of Bmi-1 protein, and H3K27me3 and H2AK119ub modification. The ubiquitin-mediated proteasomal degradation pathway plays a critical role in the downregulation of associated proteins following HSANPs-PEI@EZH2siRNA exposure to AML cells. c-Myb is the AML-responsive transcription factor that directly binds on the EZH2 promoter and was downregulated in HSANPs-PEI@EZH2siRNA-treated AML cells. The systemic exposure to HSANPs-PEI@EZH2siRNA of AML engrafted immunodeficient nude mice displayed efficient EZH2 gene silencing and a reduced AML cell population in peripheral blood and bone marrow. The present study demonstrates a non-viral siRNA delivery system for epigenetic targeting based superior anti-leukemic therapy.

Codelivery of HIF-1α siRNA and Dinaciclib by Carboxylated Graphene Oxide-Trimethyl Chitosan-Hyaluronate Nanoparticles Significantly Suppresses Cancer Cell Progression

PURPOSE

Hypoxia-inducible factor (HIF) is one of the critical components of the tumor microenvironment that is involved in tumor development. HIF-1α functionally and physically interacts with CDK1, 2, and 5 and stimulates the cell cycle progression and Cyclin-Dependent Kinase (CDK) expression. Therefore, hypoxic tumor microenvironment and CDK overexpression lead to increased cell cycle progression and tumor expansion. Therefore, we decided to suppress cancer cell expansion by blocking HIF-1α and CDK molecules.

METHODS

In the present study, we used the carboxylated graphene oxide (CGO) conjugated with trimethyl chitosan (TMC) and hyaluronate (HA) nanoparticles (NPs) loaded with HIF-1α-siRNA and Dinaciclib, the CDK inhibitor, for silencing HIF-1α and blockade of CDKs in CD44-expressing cancer cells and evaluated the impact of combination therapy on proliferation, metastasis, apoptosis, and tumor growth.

RESULTS

The results indicated that the manufactured NPs had conceivable physicochemical properties, high cellular uptake, and low toxicity. Moreover, combination therapy of cancer cells using CGO-TMC-HA NPs loaded with HIF-1α siRNA and Dinaciclib (SCH 727965) significantly suppressed the CDKs/HIF-1α and consequently, decreased the proliferation, migration, angiogenesis, and colony formation in tumor cells.

CONCLUSIONS

These results indicate the ability of CGO-TMC-HA NPs for dual drug/gene delivery in cancer treatment. Furthermore, the simultaneous inhibition of CDKs/HIF-1α can be considered as a novel anti-cancer treatment strategy; however, further research is needed to confirm this treatment in vivo. Graphical Abstract The suppression of HIF-1α and CDKs inhibits cancer growth. HIF-1α is overexpressed by the cells present in the tumor microenvironment. The hypoxic environment elevates mitochondrial ROS production and increases p38 MAP kinase, JAK/STAT, ERK, JNK, and Akt/PI3K signaling, resulting in cyclin accumulation and aberrant cell cycle progression. Furthermore, the overexpression of HIF-1α/CDK results in increased expression of genes such as BCL2, Bcl-xl, Ki-67, TGFβ, VEGF, FGF, MMP2, MMP9, and, HIF-1α and consequently raise the survival, proliferation, angiogenesis, metastasis, and invasion of tumor cells. In conclusion, HIF-1α-siRNA/Dinaciclib-loaded CGO-TMC-HA NPs can inhibit the tumor expansion by blockage of CDKs and HIF-1α (JAK: Janus kinase, STAT: Signal transducer and activator of transcription, MAPK: mitogen-activated protein kinase, ERK: extracellular signal-regulated kinase, JNK: c-Jun N-terminal kinase, PI3K: phosphatidylinositol 3-kinase).

Nucleic Acid-Based Approaches for Tumor Therapy

Within the last decade, the introduction of checkpoint inhibitors proposed to boost the patients' anti-tumor immune response has proven the efficacy of immunotherapeutic approaches for tumor therapy. Furthermore, especially in the context of the development of biocompatible, cell type targeting nano-carriers, nucleic acid-based drugs aimed to initiate and to enhance anti-tumor responses have come of age. This review intends to provide a comprehensive overview of the current state of the therapeutic use of nucleic acids for cancer treatment on various levels, comprising (i) mRNA and DNA-based vaccines to be expressed by antigen presenting cells evoking sustained anti-tumor T cell responses, (ii) molecular adjuvants, (iii) strategies to inhibit/reprogram tumor-induced regulatory immune cells e.g., by RNA interference (RNAi), (iv) genetically tailored T cells and natural killer cells to directly recognize tumor antigens, and (v) killing of tumor cells, and reprograming of constituents of the tumor microenvironment by gene transfer and RNAi. Aside from further improvements of individual nucleic acid-based drugs, the major perspective for successful cancer therapy will be combination treatments employing conventional regimens as well as immunotherapeutics like checkpoint inhibitors and nucleic acid-based drugs, each acting on several levels to adequately counter-act tumor immune evasion.

Doxorubicin exhibits strong and selective association with VEGF Pu22 G-quadruplex

BACKGROUND

Vascular endothelial growth factor (VEGF), is upregulated in tumor cells and thus became a potential therapeutic target for anti-cancer drugs. Recent reports suggested the use of Doxorubicin (Dox) with VEGF-targeting siRNAs for an enhanced decrease in VEGF expression. Besides, VEGF-B gene therapy was found to suppress the cardiotoxicity effects of Dox. On the other hand, even though Dox is a commonly used anti-cancer agent, its mechanism of actions isn't completely mapped out. Herein, the interactions between a G4 structure formed by the VEGF promoter region Pu₂₂ and Dox were investigated.

METHODS

The Dox-G4 interactions were examined via competition dialysis, UV-vis Absorption, Circular Dichroism (CD) and Fluorescence spectroscopy.

RESULTS

The results demonstrated that Dox was stabilizing the VEGF Pu₂₂ G4 structure and the calculated association constant for VEGF Pu₂₂-G4 complex (K_a = 7.50 × 10⁶) was very close to the reported K_a values for Dox-dsDNA complexes. Additionally, the competition dialysis experiments revealed the selectivity of Dox to Pu₂₂ compared to other G4 structures formed in telomeric repeats and promoter regions such as BCL-2 and C-myc.

CONCLUSIONS

Dox exhibits strong and selective association with VEGF Pu₂₂ G4 structure that was comparable to its well-known association with dsDNA.

GENERAL SIGNIFICANCE

The results presented here might be useful in the general area of antitumor drug-DNA interactions. Doxorubicin's significant affinity to VEGF Pu₂₂ G4 might be one of the plausible mechanisms behind its anti-tumor activity.

Intracellular Fate and Impact on Gene Expression of Doxorubicin/Cyclodextrin-Graphene Nanomaterials at Sub-Toxic Concentration

The graphene road in nanomedicine still seems very long and winding because the current knowledge about graphene/cell interactions and the safety issues are not yet sufficiently clarified. Specifically, the impact of graphene exposure on gene expression is a largely unexplored concern. Herein, we investigated the intracellular fate of graphene (G) decorated with cyclodextrins (CD) and loaded with doxorubicin (DOX) and the modulation of genes involved in cancer-associated canonical pathways. Intracellular fate of GCD@DOX, tracked by FLIM, Raman mapping and fluorescence microscopy, evidenced the efficient cellular uptake of GCD@DOX and the presence of DOX in the nucleus, without graphene carrier. The NanoString nCounter™ platform provided evidence for 34 (out of 700) differentially expressed cancer-related genes in HEp-2 cells treated with GCD@DOX (25 µg/mL) compared with untreated cells. Cells treated with GCD alone (25 µg/mL) showed modification for 16 genes. Overall, 14 common genes were differentially expressed in both GCD and GCD@DOX treated cells and 4 of these genes with an opposite trend. The modification of cancer related genes also at sub-cytotoxic G concentration should be taken in consideration for the rational design of safe and effective G-based drug/gene delivery systems. The reliable advantages provided by NanoString^® technology, such as sensibility and the direct RNA measurements, could be the cornerstone in this field.

Targeting the undruggable in pancreatic cancer using nano-based gene silencing drugs

Pancreatic cancer is predicted to be the second leading cause of cancer-related death by 2025. The best chemotherapy only extends survival by an average of 18 weeks. The extensive fibrotic stroma surrounding the tumor curbs therapeutic options as chemotherapy drugs cannot freely penetrate the tumor. RNA interference (RNAi) has emerged as a promising approach to revolutionize cancer treatment. Small interfering RNA (siRNA) can be designed to inhibit the expression of any gene which is important given the high degree of genetic heterogeneity present in pancreatic tumors. Despite the potential of siRNA therapies, there are hurdles limiting their clinical application such as poor transport across biological barriers, limited cellular uptake, degradation, and rapid clearance. Nanotechnology can address these challenges. In fact, the past few decades have seen the conceptualization, design, pre-clinical testing and recent clinical approval of a RNAi nanodrug to treat disease. In this review, we comment on the current state of play of clinical trials evaluating siRNA nanodrugs and review pre-clinical studies investigating the efficacy of siRNA therapeutics in pancreatic cancer. We assess the physiological barriers unique to pancreatic cancer that need to be considered when designing and testing new nanomedicines for this disease.

Efficient miRNA Inhibitor with GO-PEI Nanosheets for Osteosarcoma Suppression by Targeting PTEN

BACKGROUND

Gene therapy is considered a novel way to treat osteosarcoma, and microRNAs are potential therapeutic targets for osteosarcoma. miR-214 has been found to promote osteosarcoma aggression and metastasis. Graphene oxide (GO) is widely used for gene delivery for the distinct physiochemical properties and minimal cytotoxicity.

METHODS

Polyethyleneimine (PEI)-functionalized GO complex was well-prepared and loaded with miR-214 inhibitor at different concentrations. The load efficacy was tested by gel retardation assay and the cy3-labeled fluorescence of cellular uptake. The experiments of wound healing, immunofluorescence staining, Western blot, qRT-PCR and immunohistochemical staining were performed to measure the inhibitory effect of the miR-214 inhibitor systematically released from the complexes against MG63, U2OS cells and xenograft tumors.

RESULTS

The systematic mechanistic elucidation of the efficient delivery of the miR-214 inhibitor by GO-PEI indicated that the inhibition of cellular miR-214 caused a decrease in osteosarcoma cell invasion and migration and an increase in apoptosis by targeting phosphatase and tensin homolog (PTEN). The synergistic combination of the GO-PEI-miR-214 inhibitor and CDDP chemotherapy showed significant cell death. In a xenograft mouse model, the GO-PEI-miR-214 inhibitor significantly inhibited tumor volume growth.

CONCLUSION

This study indicates the potential of functionalized GO-PEI as a vehicle for miRNA inhibitor delivery to treat osteosarcoma with low toxicity and miR-214 can be a good target for osteosarcoma therapy.

Graphene oxide as a 2D platform for complexation and intracellular delivery of siRNA

The development of efficient and safe nucleic acid delivery vectors remains an unmet need holding back translation of gene therapy approaches to the bedside. Graphene oxide (GO) could help bypass such bottlenecks, thanks to its large surface area, versatile chemistry and biocompatibility, which could overall enhance transfection efficiency while abolishing some of the limitations linked to the use of viral vectors. Here, we aimed to assess the capacity of bare GO, without any further surface modification, to complex a short double-stranded nucleic acid of biological relevance (siRNA) and mediate its intracellular delivery. GO formed stable complexes with siRNA at 10 : 1, 20 : 1 and 50 : 1 GO : siRNA mass ratios. Complexation was further corroborated by atomistic molecular dynamics simulations. GO : siRNA complexes were promptly internalized in a primary mouse cell culture, as early as 4 h after exposure. At this time point, intracellular siRNA levels were comparable to those provided by a lipid-based transfection reagent that achieved significant gene silencing. The time-lapse tracking of internalized GO and siRNA evidenced a sharp decrease of intracellular siRNA from 4 to 12 h, while GO was sequestered in large vesicles, which may explain the lack of biological effects (i.e. gene silencing) achieved by GO : siRNA complexes. This study underlines the potential of non-surface modified GO flakes to act as 2D siRNA delivery platforms, without the need for cationic functionalization, but warrants further vector optimization to allow the effective release of the nucleic acid and achieve efficient gene silencing.

Dual targeted and pH-responsive gold nanorods with improved chemotherapy and photothermal ablation for synergistic cancer treatment

Cancer is considered to be one of the leading causes of morbidity and mortality worldwide. A multifunctional nanosystem based on gold nanorods (GNRs) has demonstrated the potential to enhance therapeutic performance. In this research, dual-targeted pH-responsive GNRs for synergistic cancer treatment were developed and investigated. The GNRs could target angiogenic endothelial cells in the tumor region using αvβ3-mediated recognition and subsequently facilitate its specific binding to tumor cells mediated via recognition of the folate receptor, which could accumulate precisely at the tumor site. Doxorubicin (DOX) was loaded on to the surface of GNRs via a pH-sensitive hydrazone (hz) bond, which could effectively control the drug release by responding to the tumor acidic microenvironment. In vitro, the FA/RGD-DOX-hz-GNRs showed higher tumor specificity and killing ability under near-infrared irradiation. Furthermore, in B16-F10 xenograft tumor-bearing mice, FA/RGD-DOX-hz-GNRs produced the optimal tumor therapeutic efficacy by antagonizing angiogenesis, inhibiting cell proliferation and causing necrosis. Therefore, the strategy of integration of a photothermal effect, chemotherapy and a molecular active targeting based double-targeting mode appeared advantageous over chemotherapy or a photothermal therapy alone.

A dual-targeted pH-responsive GNR for synergistic cancer treatment was developed and investigated, which demonstrated the desired potential for enhancing therapeutic performance.