Efficient siRNA delivery and tumor accumulation mediated by ionically cross-linked folic acid–poly(ethylene glycol)–chitosan oligosaccharide lactate nanoparticles: For the potential targeted ovarian cancer gene therapy

Advances in the preparation, characterization, and biological functions of chitosan oligosaccharide derivatives: A review

Chitosan oligosaccharide (COS), which represent the positively charged basic amino oligosaccharide in nature, is the deacetylated and degraded products of chitin. COS has become the focus of intensive scientific investigation, with a growing body of practical and clinical studies highlighting its remarkable health-enhancing benefits. These effects encompass a wide range of properties, including antibacterial, antioxidant, anti-inflammatory, and anti-tumor activities. With the rapid advancements in chemical modification technology for oligosaccharides, many COS derivatives have been synthesized and investigated. These newly developed derivatives possess more stable chemical structures, improved biological activities, and find applications across a broader spectrum of fields. Given the recent interest in the chemical modification of COS, this comprehensive review seeks to consolidate knowledge regarding the preparation methods for COS derivatives, alongside discussions on their structural characterization. Additionally, various biological activities of COS derivatives have been discussed in detail. Lastly, the potential applications of COS derivatives in biomedicine have been reviewed and presented.

Hypoxia: Intriguing Feature in Cancer Cell Biology

Hypoxia, a key aspect of the tumor microenvironment, plays a vital role in cell proliferation, angiogenesis, metabolism, and the immune response within tumors. These factors collectively promote tumor advancement, aggressiveness, metastasis and result in a poor prognosis. Hypoxia inducible factor 1α (HIF-1α), activated under low oxygen conditions, mediates many of these effects by altering drug target expression, metabolic regulation, and oxygen consumption. These changes promote cancer cell growth and survival. Hypoxic tumor cells develop aggressive traits and resistance to chemotherapy and radiotherapy, leading to increased mortality. Targeting hypoxic tumor offers a potential solution to overcome the challenges posed by tumor heterogeneity and can be used in designing diagnostic and therapeutic nanocarriers for various solid cancers. This concept provides an overview of the intricate relationship between hypoxia and the tumor microenvironment, highlighting its potential as a promising tool for cancer therapies. The article explores the development of hypoxia in cancer cells and its role in cancer progression, along with the latest advancements in hypoxia-triggered cancer treatment.

Targeting endothelial permeability in the EPR effect

The characteristics of the primary tumor blood vessels and the tumor microenvironment drive the enhanced permeability and retention (EPR) effect, which confers an advantage towards enhanced delivery of anti-cancer nanomedicine and has shown beneficial effects in preclinical models. Increased vascular permeability is a landmark feature of the tumor vessels and an important driver of the EPR. The main focus of this review is the endothelial regulation of vascular permeability. We discuss current challenges of targeting vascular permeability towards clinical translation and summarize the structural components and mechanisms of endothelial permeability, the principal mediators and signaling players, the targeted approaches that have been used and their outcomes to date. We also critically discuss the effects of the tumor-infiltrating immune cells, their interplay with the tumor vessels and the impact of immune responses on nanomedicine delivery, the impact of anti-angiogenic and tumor-stroma targeting approaches, and desirable nanoparticle design approaches for greater translational benefit.

Development and Perspectives: Multifunctional Nucleic Acid Nanomedicines for Treatment of Gynecological Cancers

Gynecological malignancies are a significant cause of morbidity and mortality across the globe. Due to delayed presentation, gynecological cancer patients are often referred late in the disease's course, resulting in poor outcomes. A considerable number of patients ultimately succumb to chemotherapy-resistant disease, which reoccurs at advanced stages despite treatment interventions. Although efforts have been devoted to developing therapies that demonstrate reduced resistance to chemotherapy and enhanced toxicity profiles, current clinical outcomes remain unsatisfactory due to treatment resistance and unfavorable off-target effects. Consequently, innovative biological and nanotherapeutic approaches are imperative to strengthen and optimize the therapeutic arsenal for gynecological cancers. Advancements in nanotechnology-based therapies for gynecological malignancies offer significant advantages, including reduced toxicity, expanded drug circulation, and optimized therapeutic dosing, ultimately leading to enhanced treatment effectiveness. Recent advances in nucleic acid therapeutics using microRNA, small interfering RNA, and messenger RNA provide novel approaches for cancer therapeutics. Effective single-agent and combinatorial nucleic acid therapeutics for gynecological malignancies have the potential to transform cancer treatment by giving safer, more tailored approaches than conventional therapies. This review highlights current preclinical studies that effectively exploit these approaches for the treatment of gynecological malignant tumors and malignant ascites.

Chitosan-Based Nanoparticles for Nucleic Acid Delivery: Technological Aspects, Applications, and Future Perspectives

Chitosan is a naturally occurring polymer derived from the deacetylation of chitin, which is an abundant carbohydrate found mainly in the shells of various marine and terrestrial (micro)organisms. Chitosan has been extensively used to construct nanoparticles (NPs), which are biocompatible, biodegradable, non-toxic, easy to prepare, and can function as effective drug delivery systems. Moreover, chitosan NPs have been employed in gene and vaccine delivery, as well as advanced cancer therapy, and they can also serve as new therapeutic tools against viral infections. In this review, we summarize the most recent developments in the field of chitosan-based NPs intended as nucleic acid delivery vehicles and gene therapy vectors. Special attention is given to the technological aspects of chitosan complexes for nucleic acid delivery.

Current Update on Nanotechnology-Based Approaches in Ovarian Cancer Therapy

Ovarian cancer is one of the leading causes of cancer-related deaths among women. The drawbacks of conventional therapeutic strategies encourage researchers to look for alternative strategies, including nanotechnology. Nanotechnology is one of the upcoming domains of science that is rechanneled towards targeted cancer therapy and diagnosis. Nanocarriers such as dendrimers, liposomes, polymer micelles, and polymer nanoparticles present distinct surface characteristics in morphology, surface chemistry, and mode of action that help differentiate normal and malignant cells, which paves the way for target-specific drug delivery. Similarly, nanoparticles have been strategically utilized as efficacious vehicles to deliver drugs that alter the epigenetic modifications in epigenetic therapy. Some studies suggest that the use of specialized target-modified nanoparticles in siRNA-based nanotherapy prevents internalization and improves the antitumor activity of siRNA by ensuring unrestrained entry of siRNA into the tumor vasculature and efficient intracellular delivery of siRNA. Moreover, research findings highlight the significance of utilizing nanoparticles as depots for photosensitive drugs in photodynamic therapy. The applicability of nanoparticles is further extended to medical imaging. They serve as contrast agents in combination with conventional imaging modalities such as MRI, CT, and fluorescence-based imaging to produce vivid and enhanced images of tumors. Therefore, this review aims to explore and delve deeper into the advent of various nanotechnology-based therapeutic and imaging techniques that provide non-invasive and effective means to tackle ovarian cancers.

Recent Advancements in the Design of Nanodelivery Systems of siRNA for Cancer Therapy

RNA interference (RNAi) has increased the possibility of restoring RNA drug targets for cancer treatment. Small interfering RNA (siRNA) is a promising therapeutic RNAi tool that targets the defective gene by inhibiting its mRNA expression and stopping its translation. However, siRNAs have flaws like poor intracellular trafficking, RNase degradation, rapid kidney filtration, off-targeting, and toxicity, which limit their therapeutic efficiency. Nanocarriers (NCs) have been designed to overcome such flaws and increase antitumor activity. Combining siRNA and anticancer drugs can give synergistic effects in cancer cells, making them a significant gene-modification tool in cancer therapy. Our discussion of NCs-mediated siRNA delivery in this review includes their mechanism, limitations, and advantages in comparison with naked siRNA delivery. We will also discuss organic NCs (polymers and lipids) and inorganic NCs (quantum dots, carbon nanotubes, and gold) that have been reported for extensive delivery of therapeutic siRNA to tumor sites. Finally, we will conclude by discussing the studies based on organic and inorganic NCs-mediated siRNA drug delivery systems conducted in the years 2020 and 2021.

Modulating the tumor immune microenvironment with nanoparticles: A sword for improving the efficiency of ovarian cancer immunotherapy

With encouraging antitumor effects, immunotherapy represented by immune checkpoint blockade has developed into a mainstream cancer therapeutic modality. However, only a minority of ovarian cancer (OC) patients could benefit from immunotherapy. The main reason is that most OC harbor a suppressive tumor immune microenvironment (TIME). Emerging studies suggest that M2 tumor-associated macrophages (TAMs), T regulatory cells (Tregs), myeloid-derived suppressor cells (MDSCs), and cancer-associated fibroblasts (CAFs) are enriched in OC. Thus, reversing the suppressive TIME is considered an ideal candidate for improving the efficiency of immunotherapy. Nanoparticles encapsulating immunoregulatory agents can regulate immunocytes and improve the TIME to boost the antitumor immune response. In addition, some nanoparticle-mediated photodynamic and photothermal therapy can directly kill tumor cells and induce tumor immunogenic cell death to activate antigen-presenting cells and promote T cell infiltration. These advantages make nanoparticles promising candidates for modulating the TIME and improving OC immunotherapy. In this review, we analyzed the composition and function of the TIME in OC and summarized the current clinical progress of OC immunotherapy. Then, we expounded on the promising advances in nanomaterial-mediated immunotherapy for modulating the TIME in OC. Finally, we discussed the obstacles and challenges in the clinical translation of this novel combination treatment regimen. We believe this resourceful strategy will open the door to effective immunotherapy of OC and benefit numerous patients.

Insights on prospects of nano-siRNA based approaches in treatment of Cancer

siRNA interference, commonly referred to as gene silence, is a biological mechanism that inhibits gene expression in disorders such as cancer. It may enhance the precision, efficacy, and stability of medicines, especially genetic therapies to some extent. However, obstacles such as the delivery of oligonucleotide drugs to inaccessible areas of the body and the prevalence of severe side effects must be overcome. To maximize their potential, it is thus essential to optimize their distribution to target locations and limit their toxicity to healthy cells. The action of siRNA may be harnessed to delete a similar segment of mRNA that encodes a protein that causes sickness. The absence of an efficient delivery mechanism that shields siRNA from nuclease degradation, delivers it to cancer cells and releases it into the cytoplasm of specific cancer cells without causing side effects is currently the greatest obstacle to the practical implementation of siRNA therapy. This article focuses on combinations of siRNA with chemotherapeutic drug delivery systems for the treatment of cancer and gives an overview of several nanocarrier formulations in both research and clinical applications.

Polymeric nanoparticles-siRNA as an emerging nano-polyplexes against ovarian cancer

Ovarian cancer (OC) is considered fifth-deadliest cancer globally responsible for high mortality in women. As the conventional therapeutic and diagnostic approaches are ineffective in increasing the survival rates of advanced staged patients by more than 5 years, OC has resulted in high morbidity and mortality rates over the last two decades. As a result, there is a dire need for innovative treatment approaches to address the issues. RNAi and nanotechnology can be considered the most appropriate strategies that can be used to improve OC therapy and help circumvent the chemo-resistance. siRNA is considered highly successful in facilitating the knockdown of specific genes on entering the cytosol when administered in-vivo via inhibiting the mRNA expression responsible for translation of those specific genes through the mechanism called RNA interference (RNAi). However, the primary barrier of utmost importance in the clinical efficacy of employed siRNA for the treatment of OC is the systemic distribution to the targeted site from the administration site. As a result, nanoparticles are constructed to carry the siRNA molecules inside them to the targeted site by preventing serum degradation and enhancing the serum stability of administered siRNA. The present review assesses the developments made in the polymeric-based nanoparticle siRNA delivery for targeting particular genes involved in the prognosis of ovarian cancers and surpassing the chemo-resistance and thus improving the therapeutic potentials of administered agents.

Nanodelivery Systems Delivering Hypoxia-Inducible Factor-1 Alpha Short Interfering RNA and Antisense Oligonucleotide for Cancer Treatment

Hypoxia-inducible factor (HIF), which plays a crucial role in oxygen homeostasis, contributes to immunosuppression, tumor angiogenesis, multidrug resistance, photodynamic therapy resistance, and metastasis. HIF as a therapeutic target has attracted scientists’ strong academic research interests. Short interfering RNA (siRNA) and antisense oligonucleotide (ASO) are the more promising and broadly utilized methods for oligonucleotide-based therapy. Their physicochemical characteristics such as hydrophilicity, negative charge, and high molecular weight make them impossible to cross the cell membrane. Moreover, siRNA and ASO are subjected to a rapid deterioration in circulation and cannot translocate into nuclear. Delivery of siRNA and ASO to specific gene targets should be realized without off-target gene silencing and affecting the healthy cells. Nanoparticles as vectors for delivery of siRNA and ASO possess great advantages and flourish in academic research. In this review, we summarized and analyzed regulation mechanisms of HIF under hypoxia, the significant role of HIF in promoting tumor progression, and recent academic research on nanoparticle-based delivery of HIF siRNA and ASO for cancer immunotherapy, antiangiogenesis, reversal of multidrug resistance and radioresistance, potentiating photodynamic therapy, inhibiting tumor metastasis and proliferation, and enhancing apoptosis are reviewed in this thesis. Furthermore, we hope to provide some rewarding suggestions and enlightenments for targeting HIF gene therapy.

Gene Therapy for Malignant and Benign Gynaecological Disorders: A Systematic Review of an Emerging Success Story

Simple Summary

This review discusses all the major advances in gene therapy of gynaecological disorders, highlighting the novel and potentially therapeutic perspectives associated with such an approach. It specifically focuses on the gene therapy strategies against major gynaecological malignant disorders, such as ovarian, cervical, and endometrial cancer, as well as benign disorders, such as uterine leiomyomas, endometriosis, placental, and embryo implantation disorders. The above therapeutic strategies, which employ both viral and non-viral systems for mutation compensation, suicide gene therapy, oncolytic virotherapy, antiangiogenesis and immunopotentiation approaches, have yielded promising results over the last decade, setting the grounds for successful clinical trials.

Abstract

Despite the major advances in screening and therapeutic approaches, gynaecological malignancies still present as a leading cause of death among women of reproductive age. Cervical cancer, although largely preventable through vaccination and regular screening, remains the fourth most common and most lethal cancer type in women, while the available treatment schemes still pose a fertility threat. Ovarian cancer is associated with high morbidity rates, primarily due to lack of symptoms and high relapse rates following treatment, whereas endometrial cancer, although usually curable by surgery, it still represents a therapeutic problem. On the other hand, benign abnormalities, such as fibroids, endometriosis, placental, and embryo implantation disorders, although not life-threatening, significantly affect women’s life and fertility and have high socio-economic impacts. In the last decade, targeted gene therapy approaches toward both malignant and benign gynaecological abnormalities have led to promising results, setting the ground for successful clinical trials. The above therapeutic strategies employ both viral and non-viral systems for mutation compensation, suicide gene therapy, oncolytic virotherapy, antiangiogenesis and immunopotentiation. This review discusses all the major advances in gene therapy of gynaecological disorders and highlights the novel and potentially therapeutic perspectives associated with such an approach.

Targeting colon cancer stem cells using novel doublecortin like kinase 1 antibody functionalized folic acid conjugated hesperetin encapsulated chitosan nanoparticles

The cancer stem cell (CSC) hypothesis is an evolving oncogenesis concept. CSCs have a distinct ability to self-renew themselves and also give rise to a phenotypically diverse population of cells. Targeting CSCs represents a promising strategy for cancer treatment. Plant-derived compounds are potent in restricting the expansion of CSCs. DCLK1 has been already reported as a colon CSC specific marker. Nanoparticles can effectively inhibit multiple types of CSCs by targeting specific markers. We have synthesized DCLK1 functionalized folic acid conjugated hesperetin encapsulated chitosan nanoparticles (CFH-DCLK1), specifically to target CSCs. In this regard, we have performed proliferation assay, colony formation assay, cell migration assay, apoptosis assay, flow cytometry analysis, real-time RT- PCR and western blot analyses to determine the effect of CFH-DCLK1 and CFH nanoparticles in HCT116-colon cancer cells. In our study, we have determined the median inhibitory concentration (IC50) of CFH (47.8 µM) and CFH-DCLK1 (4.8 µM) nanoparticles in colon cancer cells. CFH-DCLK1 nanoparticles induced apoptosis and inhibited the migration and invasion of colon cancer cells. Real time PCR and western blot results have demonstrated that the treatment with CFH-DCLK1 nanoparticles significantly reduced the expression of CSC markers such as DCLK1, STAT1 and NOTCH1 compared to the CFH alone in HCT116 colon cancer cells. Finally, in the 3D spheroid model, CFH-DCLK1 nanoparticles significantly inhibited the colonosphere growth. Overall, our results highlight the effectiveness of CFH-DCLK1 nanoparticles in targeting the colon cancer cells and CSCs. This study would lead to the development of therapies targeting both cancer cells and CSCs simultaneously using nanoformulated drugs, which could bring changes in the current cancer treatment strategies.

Drug delivery systems for cancer treatment: a review of marine-derived polysaccharides

Abstract:

Cancer is a disease characterized by uncontrolled cell proliferation and the spread of cells to other tissues and remains one of the worldwide problems waiting to be solved. There are various treatment strategies for cancer, such as chemotherapy, surgery, radiotherapy, and immunotherapy, although it varies according to its type and stage. Many chemotherapeutic agents have limited clinical use due to lack of efficacy, off-target toxicity, metabolic instability, or poor pharmacokinetics. One possible solution to this high rate of clinical failure is to design drug delivery systems that deliver drugs in a controlled and specific manner and are not toxic to normal cells. Marine systems contain biodiversity, including components and materials that can be used in biomedical applications and therapy. Biomaterials such as chitin, chitosan, alginate, carrageenan, fucoidan, hyaluronan, agarose, and ulvan obtained from marine organisms have found use in DDSs today. These polysaccharides are biocompatible, non-toxic, biodegradable, and cost-effective, making them ideal raw materials for increasingly complex DDSs with a potentially regulated release. In this review, the contributions of polysaccharides from the marine environment to the development of anticancer drugs in DDSs will be discussed.

Research progress of nanocarriers for gene therapy targeting abnormal glucose and lipid metabolism in tumors

In recent years, the incidence of various types of tumors has gradually increased, and it has also been found that there is a certain correlation between abnormal glucose and lipid metabolism and tumors. Glycolipid metabolism can promote tumor progression through multiple pathways, and the expression of related genes also directly or indirectly affects tumor metabolism, metastasis, invasion, and apoptosis. There has been much research on targeted drug delivery systems designed for abnormal glucose and lipid metabolism due to their accuracy and efficiency when used for tumor therapy. In addition, gene mutations have become an important factor in tumorigenesis. For this reason, gene therapy consisting of drugs designed for certain specifically expressed genes have been transfected into target cells to express or silence the corresponding proteins. Targeted gene drug vectors that achieve their corresponding therapeutic purposes are also rapidly developing. The genes related to glucose and lipid metabolism are considered as the target, and a corresponding gene drug carrier is constructed to influence and interfere with the expression of related genes, so as to block the tumorigenesis process and inhibit tumor growth. Designing drugs that target genes related to glucose and lipid metabolism within tumors is considered to be a promising strategy for the treatment of tumor diseases. This article summarizes the chemical drugs/gene drug delivery systems and the corresponding methods used in recent years for the treatment of abnormal glucose and lipid metabolism of tumors, and provides a theoretical basis for the development of glucolipid metabolism related therapeutic methods.

Blockade of CD73 using siRNA loaded chitosan lactate nanoparticles functionalized with TAT-hyaluronate enhances doxorubicin mediated cytotoxicity in cancer cells both in vitro and in vivo

Chemotherapy drugs are still one of the first treatment options used in many cancers; however, problems such as cytotoxic side effects on normal cells after systemic administration and resistance to treatment have reduced the use of chemotherapeutics day by day. Targeted delivery of these drugs to the tumor site and sensitization of cancer cells to death induced by chemotherapy drugs are ways that can overcome the limitations of the use of these drugs. In this study, we designed and generated a novel nanocarrier composed of chitosan lactate nanoparticles (NPs) functionalized by HIV-1 derived TAT peptide (Transactivating transcriptional activator) and hyaluronate (HA) to deliver CD73 siRNA and doxorubicin to 4T1 and CT26 cancer cells, both in vivo and in vitro, as a novel combinatorial treatment strategy. The CD73 molecule plays a key role in many cancer cell behaviors such as proliferation, angiogenesis, metastasis, imunosuppression, and resistance to chemotherapy. Therefore, we decided to reduce the side effects of DOX by simultaneously transmitting CD73 siRNA and DOX by CL-TAT-HA NPs, increase the susceptibility of cancer cells to DOX-induced cell death, and stimulate anti-tumor immune responses, for the first time. These results indicated that simultaneous transfer of CD73 siRNA and DOX to cancer cells (4 T1 and CT26) increased cell death and inhibited the prolifration and spread of cancer cells. Also, the preferential aggregation of NPs in the tumor microenvironment reduced tumor growh, promoted the survival of tumor-bearing mice, and induced anti-tumor immune responses. These findings indicate that CL-TAT-HA NPs are a good candidate for targeted siRNA/drug delivery to cancer cells and the simultaneous transfer of CD73 siRNA and DOX to cancer cells using this nanocarrier can be used to treat cancer.

ADNP prompts the cisplatin-resistance of bladder cancer via TGF-β-mediated epithelial-mesenchymal transition (EMT) pathway

Activity-dependent neuroprotective protein (ADNP) is vital for embryonic development and brain formation. Besides, the upregulated expression of ADNP enhances tumorigenesis in some human tumors like bladder cancer (BC). However, the potential roles of ADNP in drug resistance and the related mechanisms in BC is unknown. We performed this study to elucidate the influence of ADNP in the chemoresistance of BC and tried to explore the underlying molecular mechanism. The expressions of ADNP in BC from progression and non-progression patient specimens were measured by quantitative real-time PCR (qRT-PCR) and immunohistochemistry (IHC). In vitro experiments including colony formation, cell counting kit-8 (CCK-8), wound healing, and in vivo tumorigenesis assay were performed to explore the effects of ADNP on chemoresistance of BC. The impacts of ADNP on TGF-β/Smad signaling pathways were explored by western blot. Our results showed that the expression of ADNP mRNA and protein were significantly upregulated in BC tissues of the patients who suffered tumor-progression via RT-PCR and western blot. Cox regression survival analysis revealed that patients with high ADNP expression closely linked to shorter tumor-free survival. ADNP downregulation in BC showed more sensitive to cisplatin in vivo, while ADNP overexpression showed the opposite results. Additionally, we confirmed that ADNP promoted cell migration and EMT, thereby inducing cisplatin resistance, which may be related to TGF-β / Smad signaling pathway.

Simultaneous inhibition of CD73 and IL-6 molecules by siRNA-loaded nanoparticles prevents the growth and spread of cancer

High concentrations of adenosine and interleukin (IL)-6 in the tumor microenvironment have been identified as one of the leading causes of cancer growth. Thus, we decided to inhibit the growth of cancer cells by inhibiting the production of adenosine and IL-6 in the tumor environment at the same time. For this purpose, we used chitosan-lactate-PEG-TAT (CLP-TAT) nanoparticles (NPs) loaded with siRNA molecules against CD73, an adenosine-producing enzyme, and IL-6. Proper physicochemical properties of the produced NPs led to high cell uptake and suppression of target molecules. Administration of these NPs to tumor-bearing mice (4T1 and CT26 models) greatly reduced the size of the tumor and increased the survival of the mice, which was accompanied by an increase in anti-tumor T lymphocyte responses. These findings suggest that combination therapy using siRNA-loaded CLP-TAT NPs against CD73 and IL-6 molecules could be an effective treatment strategy against cancer that needs further study.

Chitosan Nanomedicine in Cancer Therapy: Targeted Delivery and Cellular Uptake

Nanomedicine has gained much attention for the management and treatment of cancers due to the distinctive physicochemical properties of the drug-loaded particles. Chitosan's cationic nature is attractive for the development of such particles for drug delivery, transfection, and controlled release. The particle properties can be improved by modification of the polymer or the particle themselves. The physicochemical properties of chitosan particles are analyzed in 126 recent studies, which allows to highlight their impact on passive and active targeted drug delivery, cellular uptake, and tumor growth inhibition (TGI). From 2012 to 2019, out of 40 in vivo studies, only 4 studies are found reporting a reduction in tumor size by using chitosan particles while all other studies reported tumor growth inhibition relative to controls. A total of 23 studies are analyzed for cellular uptake including 12 studies reporting cellular uptake mechanisms. Understanding and exploiting the processes involved in targeted delivery, endocytosis, and exocytosis by controlling the physicochemical properties of chitosan particles are important for the development of safe and efficient nanomedicine. It is concluded based on the recent literature available on chitosan particles that combination therapies can play a pivotal role in transformation of chitosan nanomedicine from bench to bedside.

Folate Receptor-Mediated siRNA Delivery: Recent Developments and Future Directions for RNAi Therapeutics

RNA interference (RNAi), a gene regulatory process mediated by small interfering RNAs (siRNAs), has made remarkable progress as a potential therapeutic agent against various diseases. However, RNAi is associated with fundamental challenges such as poor systemic delivery and susceptibility to the nucleases. Targeting ligand-bound delivery vehicles has improved the accumulation of drug at the target site, which has resulted in high transfection efficiency and enhanced gene silencing. Recently, folate receptor (FR)-mediated targeted delivery of siRNAs has garnered attention due to their enhanced cellular uptake and high transfection efficiency toward tumor cells. Folic acid (FA), due to its small size, low immunogenicity, high in vivo stability, and high binding affinity toward FRs, has attracted much attention for targeted siRNA delivery. FRs are overexpressed in a large number of tumors, including ovarian, breast, kidney, and lung cancer cells. In this review, we discuss recent advances in FA-mediated siRNA delivery to treat cancers and inflammatory diseases. This review summarizes various FA-conjugated nanoparticle systems reported so far in the literature, including liposome, silica, metal, graphene, dendrimers, chitosan, organic copolymers, and RNA nanoparticles. This review will help in the design and development of potential delivery vehicles for siRNA drug targeting to tumor cells using an FR-mediated approach.

Metformin-conjugated micellar system with intratumoral pH responsive de-shielding for co-delivery of doxorubicin and nucleic acid

A novel PMet-P(cdmPEG_2K) polymeric micellar carrier was developed for tumor-targeted co-delivery of DOX and nucleic acids (NA), based on polymetformin and a structure designed to lose the PEG shell in response to the acidic extracellular tumor environment. NA/DOX co-loaded micelleplexes exhibited enhanced inhibition of cell proliferation compared to DOX-loaded micelles, and displayed a higher level of cytotoxicity at an acidic pH (6.8) which mimicks the tumor microenvironment. The PMet-P(cdmPEG_2K) micelles achieved significantly improved transfection with either a reporter plasmid or Cy3-siRNA, and enhanced DOX intracellular uptake in 4T1.2 cells at pH 6.8. Importantly, PMet-P(cdmPEG_2K) micelles showed excellent pEGFP (EGFP expression plasmid) transfection in an aggressive murine breast cancer (4T1.2) model. By using a plasmid encoding IL-12 (pIL-12), we investigated the combined effect of chemotherapy and gene therapy. PMet-P(cdmPEG_2K) micelles co-loaded with DOX and pIL-12 were more effective at inhibiting tumor growth compared to micelles loaded with DOX or pIL-12 alone. In addition, this micellar system was effective in co-delivery of siRNA and DOX into tumor cells. Our results suggest that PMet-P(cdmPEG_2K) has the potential for chemo and nucleic acid combined cancer therapy.

Recent Progresses in Organic-Inorganic Nano Technological Platforms for Cancer Therapeutics

Nanotechnology offers promising tools in interdisciplinary research areas and getting an upsurge of interest in cancer therapeutics. Organic nanomaterials and inorganic nanomaterials bring revolutionary advancement in cancer eradication process. Oncology is achieving new heights under nano technological platform by expediting chemotherapy, radiotherapy, photo thermodynamic therapy, bio imaging and gene therapy. Various nanovectors have been developed for targeted therapy which acts as "Nano-bullets" for tumor cells selectively. Recently combinational therapies are catching more attention due to their enhanced effect leading towards the use of combined organicinorganic nano platforms. The current review covers organic, inorganic and their hybrid nanomaterials for various therapeutic action. The technological aspect of this review emphasizes on the use of inorganic-organic hybrids and combinational therapies for better results and also explores the future opportunities in this field.

Nanoparticulate RNA delivery systems in cancer

BACKGROUND

Drug delivery system is a common practice in cancer treatment. RNA interference-mediated post-transcriptional gene silencing holds promise as an approach to knockdown in the expression of target genes responsible for cancer cell growth and metastasis. RNA interference (RNAi) can be achieved by delivering small interfering RNA (siRNA) and short hairpin RNA (shRNA) to target cells. Since neither interfering RNAs can be delivered in naked form due to poor stability, an efficient delivery system is required that protects, guides, and delivers the siRNA and shRNA to target cells as part of cancer therapy (chemotherapy).

RECENT FINDINGS

In this review, a discussion is presented about the different types of drug delivery system used to deliver siRNA and shRNA, together with an overview of the potential benefits associated with this sophisticated biomolecular therapy. Improved understanding of the different approaches used in nanoparticle (NP) fabrication, along with an enhanced appreciation of the biochemical properties of siRNA/shRNA, will assist in developing improved drug delivery strategies in basic and clinical research.

CONCLUSION

These novel delivery techniques are able to solve the problems that form an inevitable part of delivering genes in more efficient manner and as part of more effective treatment protocols. The present review concludes that the nanoparticulate RNA delivery system has great possibility for cancer treatment along with several other proposed methods. Several NPs or nanocarriers are already in use, but the methods proposed here could fulfill the missing gap in cancer research. It is the future technology, which unravels the mystery of resolving genomic diseases that is, especially genomic instability and its signaling cascades.

Targeting CD146 using folic acid-conjugated nanoparticles and suppression of tumor growth in a mouse glioma model

OBJECTIVE

Glioma stem cells (GSCs) are responsible for tumor initiation, therapeutic resistance, and recurrence. CD146 is mainly expressed in dividing GSCs and regulates cell cycle progression. However, the evaluation of the efficacy of targeted therapy against CD146 in vivo remains to be investigated. In this study, the authors aimed to develop gene therapy targeting GSCs using chitosan oligosaccharide lactate (COL) nanoparticles (NPs) conjugated with folic acid-polyethylene glycol (FA-PEG-COL NPs) for in vitro and in vivo delivery of CD146 small-interfering RNA (siCD146) and to determine the effect of CD146 knockdown on tumor growth.

METHODS

To examine the uptake of NPs by tumor cells, immunofluorescence staining, flow cytometry, and in vivo imaging were performed. The knockdown effect of siCD146 was measured by western blot and water-soluble tetrazolium salt-8 assay in mouse glioma cells. The efficacy of siRNA therapy-targeted GSCs was evaluated by monitoring tumor growth through in vivo imaging and histological analysis.

RESULTS

In vivo accumulation of the FA-PEG-COL NPs in subcutaneous and intracranial gliomas following NP administration via a mouse tail vein was observed. Additionally, in vitro delivery of siCD146 ionically cross-linked NPs, reduced CD146 levels, and suppressed growth in the glioma tumor sphere. Evaluation of the in vivo therapeutic effects of siCD146-cross-linked NPs in a mouse glioma model revealed significant suppression of intracranial tumor growth, with complete removal of the tumor observed in some mice on histological examination. Furthermore, delivery of siCD146 significantly reduced the Ki-67 index in residual tumor tissues relative to that in control mice.

CONCLUSIONS

CD146 is a potential therapeutic target, and folic acid-conjugated NPs delivering siRNA may facilitate gene therapy in malignant gliomas.

Recent Advancement of Molecular Structure and Biomaterial Function of Chitosan from Marine Organisms for Pharmaceutical and Nutraceutical Application

Chitosan is an innate cationic biological polysaccharide polymer, naturally obtained from chitin deacetylation, that possesses broad-spectrum properties such as antibacterial, biodegradability, biocompatibility, non-toxic, non-immunogenicity, and so on. Chitosan can be easily modified owing to its molecular chain that contains abundant active amino and hydroxyl groups, through various modifications. Not only does it possess excellent properties but it also greatly accelerates its solubility and endows it with additional special properties. It can be developed into bioactive materials with innovative properties, functions, and multiple uses, especially in the biomedical fields. In this paper, the unique properties and the relationship between the molecular structure of chitosan and its derivatives are emphasized, an overview of various excellent biomedical properties of chitosan and its current progress in the pharmaceutical and nutraceutical field have prospected, to provide the theoretical basis for better development and utilization of new biomedical materials of chitosan and its derivatives.

Current developments in nanotechnology for improved cancer treatment, focusing on tumor hypoxia

Hypoxia is a common feature of the tumor microenvironment, which is characterized by tissue oxygen deficiency due to an aggressive proliferation of cancer cells. Hypoxia activates hypoxia-inducible factor-dependent signaling, which in turn regulates metabolic reprogramming, immune suppression, resistance to apoptosis, angiogenesis, metastasis, and invasion to secondary sites. In this review, we provide an overview of the use of nanotechnology to harmonize intra-tumoral oxygen or suppress hypoxia-related signaling for an improved efficacy of cancer treatment. The biological background was followed by conducting a literature review on the (1) nanoparticles responsible for enhancing oxygen levels within the tumor, (2) nanoparticles sensitizing hypoxia, (3) nanoparticles suppressing hypoxia-inducing factor, (4) nanoparticles that relieve tumor hypoxia for enhancement of chemotherapy, photodynamic therapy, and immunotherapy, either individually or in combination. Lastly, the heterogeneity of cancer and limitations of nanotechnology are discussed to facilitate translational therapeutic treatment.

Nanoscale drug delivery strategies for therapy of ovarian cancer: conventional vs targeted

Ovarian cancer is the second most common gynaecological malignancy. It usually occurs in women older than 50 years, and because 75% of cases are diagnosed at stage III or IV it is associated with poor diagnosis. Despite the chemosensitivity of intraperitoneal chemotherapy, the majority of patients is relapsed and eventually dies. In addition to the challenge of early detection, its treatment presents several challenges like the route of administration, resistance to therapy with recurrence and specific targeting of cancer to reduce cytotoxicity and side effects. In ovarian cancer therapy, nanocarriers help overcome problems of poor aqueous solubility of chemotherapeutic drugs and enhance their delivery to the tumour sites either by passive or active targeting, and thus reducing adverse side effects to the healthy tissues. Moreover, the bioavailability to the tumour site is increased by the enhanced permeability and retention (EPR) mechanism. The present review aims to describe the current conventional treatment with special reference to passively and actively targeted drug delivery systems (DDSs) towards specific receptors designed against ovarian cancer to overcome the drawbacks of conventional delivery. Conclusively, targeted nanocarriers would optimise the intra-tumour distribution, followed by drug delivery into the intracellular compartment. These features may contribute to greater therapeutic effect.

KHSRP-bound small nucleolar RNAs associate with promotion of cell invasiveness and metastasis of pancreatic cancer

KH-type splicing regulatory protein (KHSRP) is an RNA-binding protein implicated in a variety of cellular processes, including splicing in the nucleus and mRNA localization and degradation in the cytoplasm. The present study reports that KHSRP promotes invasiveness and metastasis of pancreatic cancer cells. KHSRP was localized in the nucleus and cell protrusions of pancreatic cancer cell lines. Suppression of KHSRP by small interfering RNA decreased the number of cell protrusions and inhibited invasiveness and metastasis of pancreatic cancer cells. KHSRP was localized in cytoplasmic RNA granules in pancreatic cancer cells, and RNA immunoprecipitation-sequencing analysis showed that the majority of enriched RNAs that immunoprecipitated with KHSRP were small nucleolar RNAs (snoRNAs). Specific KHSRP-bound snoRNAs, SNORA18 and SNORA22, associated with formation of cell protrusions. Consequently, SNORA18 and SNORA22 contributed to cell invasiveness and tumor metastasis. Our results provide insight into the link between KHSRP-bound snoRNAs and invasiveness and metastasis of pancreatic cancers. New therapies that prevent binding of KHSRP with specific snoRNAs may hold significant clinical promise.

Chitosan is a potential inhibitor of ovarian cancer: Molecular aspects

Although ovarian cancer has a lower prevalence than breast cancer, its mortality rate is three times higher, which is reported to increase in the coming years. As the early stages of ovarian cancer do not have any obvious symptoms, in most of the cases, this cancer is diagnosed at advanced stages with a poor prognosis. Moreover, in many patients who are diagnosed with advanced stage, relapse of the disease and drug resistance are observed. Over the past years, these women have been treated with chemotherapy and cytoreductive surgeries. However, the chemotherapy could affect the healthy tissues in addition to the malignancies. Therefore, discovering new diagnostic and therapeutic options seems to be a crucial need. Unlike the common invasive and/or nonspecific treatments, nanomedicine is trying to find a new way for cancer imaging, diagnosis, and drug delivery method. Nanoparticles (NPs), which has recently drawn attention, can be used in order to reduce the toxicity and frequent dosing of drugs, tumor-specific delivery, and early diagnosis for malignancies. Chitosan as an NP and product of chitin deacetylation has multiple characteristics, including biocompatibility, biodegradability, and safety. In this review, we cover the studies concerned with the role of chitosan in finding solutions to overcome the problems faced in ovarian cancer treatments. Furthermore, we highlight how chitosan is being used in delivering chemotherapy drugs, gene therapy, and imaging methods for both detection and image-guided therapies.

Folate-conjugated nanovehicles: Strategies for cancer therapy

Cancer theranostics represents a strategy that aims at combining diagnosis with therapy through the simultaneous imaging and targeted delivery of therapeutics to cancer cells. Recently, the folate receptor alpha has emerged as an attractive theranostic target due to its overexpression in multiple solid tumors and its great functional versatility. In fact, it can be incorporated into folate-conjugated nano-systems for imaging and drug delivery. Hence, it can be used along the line of personalized clinical strategies as both an imaging tool and a delivery method ensuring the selective transport of treatments to tumor cells, thus highlighting its theranostic qualities. In this review, we will explore these theranostic characteristics in detail and assess their clinical potential. We will also discuss the technological advances that have allowed the design of sophisticated folate-based nanocarriers harboring various chemical properties and suited for the transport of various therapeutic agents.

Nanoparticle-siRNA: a potential strategy for ovarian cancer therapy?

Ovarian cancer is one of the most common causes of mortality throughout the world. Unfortunately, chemotherapy has failed to cure advanced cancers developing multidrug resistance (MDR). Moreover, it has critical side effects because of nonspecific toxicity. Thanks to specific silencing of oncogenes and MDR-associated genes, nano-siRNA drugs can be a great help address the limitations of chemotherapy. Here, we review the current advances in nanoparticle-mediated siRNA delivery strategies such as polymeric- and lipid-based systems, rigid nanoparticles and nanoparticles coupled to specific ligand systems. Nanoparticle-based codelivery of anticancer drugs and siRNA targeting various mechanisms of MDR is a cutting-edge strategy for ovarian cancer therapy, which is completely discussed in this review.

Gold nanoparticles with chitosan, N-acylated chitosan, and chitosan oligosaccharide as DNA carriers

Currently, gold nanoparticles have found applications in engineering and medical sciences, taking advantage from their properties and characteristics. Surface plasmon resonance, for instance, is one of the main features for optical applications and other physical properties, like high density, that represents the key for cellular uptake. Among other applications, in the medical field, some diseases may be treated by using gene therapy, including monogenetic or polygenetic disorders and infections. Gene adding, suppression, or substitution is one of the many options for genetic manipulation. This work explores an alternative non-viral method for gene transfer by using gold nanoparticles functionalized with organic polymers; two routes of synthesis were used: one of them with sodium borohydride as reducing agent and the other one with chitosan oligosaccharide as reducing and stabilizing agent. Gold nanoparticles conjugated with chitosan, acylated chitosan and chitosan oligosaccharide, were used to evaluate transfection efficiency of plasmid DNA into cell culture (HEK-293). Physical and chemical properties of gold nanocomposites were characterized by using UV-Vis Spectroscopy, ξ-potential, and transmission electron microscopy. Furthermore, the interaction between gold nanoparticles and plasmid DNA was demonstrated by using agarose gel electrophoresis. Transfection tests were performed and evaluated by β-galactosidase activity and green fluorescence protein expression. The percentage of transfection obtained with chitosan, acylated chitosan, and chitosan oligosaccharide were of 27%, 33%, and 60% respectively.

Elimination of HER3-expressing breast cancer cells using aptamer-siRNA chimeras

Breast cancer is the most common cancer in women worldwide. Despite recent developments in breast cancer detection and treatment, 1.38 million women each year are still affected. Breast cancer heterogeneity at the population and single-cell level, complexity and developing different metastases are setting several challenges to develop efficient breast cancer therapies. RNA interference (RNAi) represents an opportunity to silence gene expression and inhibit specific pathways in cancer cells. In order to reap the full advantages of RNAi-based therapy, different pathways that sustain cancer cells growth have been targeted using specific siRNAs. The present study investigated the ability of a set of cytotoxic siRNAs to inhibit growth of breast cancer cells. These siRNAs are targeting eukaryotic elongation factor 2 (EEF2), polo-like kinase 1 (PLK1), G protein-coupled receptor kinase 4 (GRK4) and sphingosine kinase interacting protein (SKIP5). To facilitate their targeted delivery, the human epidermal growth factor receptor-3 (HER3)-specific aptamer A30 was used. The in vitro results described in this work indicate that combining the highly specific HER3 aptamer with cytotoxic siRNAs targeting (EEF2, PLK1, GRK4 and SKIP5) can inhibit its activity and ultimately suppress proliferation of HER3 positive breast cancer cells.

Crosstalk between chitosan and cell signaling pathways

The field of tissue engineering (TE) experiences its most exciting time in the current decade. Recent progresses in TE have made it able to translate into clinical applications. To regenerate damaged tissues, TE uses biomaterial scaffolds to prepare a suitable backbone for tissue regeneration. It is well proven that the cell-biomaterial crosstalk impacts tremendously on cell biological activities such as differentiation, proliferation, migration, and others. Clarification of exact biological effects and mechanisms of a certain material on various cell types promises to have a profound impact on clinical applications of TE. Chitosan (CS) is one of the most commonly used biomaterials with many promising characteristics such as biocompatibility, antibacterial activity, biodegradability, and others. In this review, we discuss crosstalk between CS and various cell types to provide a roadmap for more effective applications of this polymer for future uses in tissue engineering and regenerative medicine.

Ligand decorated chitosan as an advanced nanocarrier for targeted delivery: a critical review

Nontargeted delivery systems present nonspecific delivery, low transfection efficiency and high toxicity. Ligand-conjugated chitosan (CS) nanocarriers have emerged as an outstanding option for achieving active delivery specifically and preferentially to the target sites by exploiting receptors mediated endocytosis. Mannosylated CS nanocarriers have brought tremendous breakthrough in gene therapy and have proven to be an excellent choice for treatment of infectious and inflammatory diseases. Similarly, folate and antibodies-conjugated CS play a significant role in diagnosis and treatment of various cancers. Current evidences obviously propose ligand-decorated CS as an attractive option for diagnosis and treatment of dreadful conditions. In order to bring huge revolution in the field of targeted delivery, challenges associated with these nanocarriers needs to be addressed.

Chitosan for gene delivery: Methods for improvement and applications

Gene therapy is a promising strategy for treating challenging diseases. The successful delivery of genes is a critical step for gene therapy. However, concerns about immunogenicity and toxicity are the main obstacles against the widespread use of effective viral systems. Therefore, nonviral vectors are regarded as good alternatives to viral vectors. Chitosan is a natural cationic polysaccharide that could be used to create nonviral gene delivery vectors. Various methods have been developed to improve the properties of chitosan related to gene delivery. This review introduces the features of chitosan in gene delivery, summarizes current progress toward methods promoting the properties of chitosan related to gene delivery, and presents different applications of chitosan in gene delivery vectors. Finally, future prospects of gene vectors based on chitosan are discussed.

Efficient delivery of small interfering RNAs targeting particular mRNAs into pancreatic cancer cells inhibits invasiveness and metastasis of pancreatic tumors

We report the use of small interfering RNAs (siRNAs) against ARHGEF4, CCDC88A, LAMTOR2, mTOR, NUP85, and WASF2 and folic acid (FA)-modified polyethylene glycol (PEG)-chitosan oligosaccharide lactate (COL) nanoparticles for targeting, imaging, delivery, gene silencing, and inhibition of invasiveness and metastasis in an orthotopic xenograft model. In vitro assays revealed that these siRNA-FA-PEG-COL nanoparticles were specifically inserted into pancreatic cancer cells compared to immortalized normal pancreatic epithelial cells and knocked down expression of the corresponding targets in pancreatic cancer cells. Cell motility and invasion were significantly inhibited by adding target siRNA-FA-PEG-COL nanoparticles into the culture medium. In vivo mouse experiments confirmed that when intravenously delivered, these siRNA-FA-PEG-COL nanoparticles became incorporated into human pancreatic cancer cells in mouse pancreatic tumors. Little accumulation was seen in the normal pancreas and vital organs. All target siRNA-FA-PEG-COL nanoparticles significantly inhibited retroperitoneal invasion. The siRNA-FA-PEG-COL nanoparticles against LAMTOR2, mTOR, and NUP85, which strongly inhibited retroperitoneal invasion and significantly inhibited peritoneal dissemination compared to the other nanoparticles, improved prognosis of the mice. Our results imply that siRNA-FA-PEG-COL nanoparticles against these six targets could have great potential as biodegradable drug carriers. In particular, siRNA nanoparticles against LAMTOR2, mTOR, and NUP85 may hold significant clinical promise.

Analysis of carbohydrates and glycoconjugates by matrix-assisted laser desorption/ionization mass spectrometry: An update for 2013-2014

This review is the eighth update of the original article published in 1999 on the application of Matrix-assisted laser desorption/ionization mass spectrometry (MALDI) mass spectrometry to the analysis of carbohydrates and glycoconjugates and brings coverage of the literature to the end of 2014. Topics covered in the first part of the review include general aspects such as theory of the MALDI process, matrices, derivatization, MALDI imaging, fragmentation, and arrays. The second part of the review is devoted to applications to various structural types such as oligo- and poly- saccharides, glycoproteins, glycolipids, glycosides, and biopharmaceuticals. Much of this material is presented in tabular form. The third part of the review covers medical and industrial applications of the technique, studies of enzyme reactions, and applications to chemical synthesis. © 2018 Wiley Periodicals, Inc. Mass Spec Rev 37:353-491, 2018.

Recent Progress in Gene Therapy for Ovarian Cancer

Ovarian cancer is the most lethal gynecological malignancy in developed countries. This is due to the lack of specific symptoms that hinder early diagnosis and to the high relapse rate after treatment with radical surgery and chemotherapy. Hence, novel therapeutic modalities to improve clinical outcomes in ovarian malignancy are needed. Progress in gene therapy has allowed the development of several strategies against ovarian cancer. Most are focused on the design of improved vectors to enhance gene delivery on the one hand, and, on the other hand, on the development of new therapeutic tools based on the restoration or destruction of a deregulated gene, the use of suicide genes, genetic immunopotentiation, the inhibition of tumour angiogenesis, the alteration of pharmacological resistance, and oncolytic virotherapy. In the present manuscript, we review the recent advances made in gene therapy for ovarian cancer, highlighting the latest clinical trials experience, the current challenges and future perspectives.

Targeted delivery of nucleic acids into xenograft tumors mediated by novel folate-equipped liposomes

Folate receptors (FR) are cellular markers highly expressed in various cancer cells. Here, we report on the synthesis of a novel folate-containing lipoconjugate (FC) built of 1,2-di-O-ditetradecyl-rac-glycerol and folic acid connected via a PEG spacer, and the evaluation of the FC as a targeting component of liposomal formulations for nucleic acid (NA) delivery into FR expressing tumor cells. FR-targeting liposomes, based on polycationic lipid 1,26-bis(cholest-5-en-3β-yloxycarbonylamino)-7,11,16,20-tetraazahexacosan tetrahydrochloride (2X3), lipid helper dioleoylphosphatidylethanolamine (DOPE) and novel FC, formed small compact particles in solution with diameters of 60 ± 22 nm, and were not toxic to cells. Complexes of NAs with the liposomes were prepared at various nitrogen to phosphate ratios (N/P) to optimize liposome/cell interactions. We showed that FR-mediated delivery of different nucleic acids mediated by 2X3-DOPE/FC liposomes occurs in vitro at low N/P (1/1 and 2/1); under these conditions FC-containing liposomes display 3-4-fold higher transfection efficiency in comparison with conventional formulation. Lipoplexes formed at N/P 1/1 by targeted liposomes and cargo (Cy7-labeled siRNA targeting MDR1 mRNA) in vivo efficiently accumulate in tumor (∼15-18% of total amount), and kidneys (71%), and were retained there for more than 24 h, causing efficient downregulation of p-glycoprotein expression (to 40% of control) in tumors. Thus, FC containing liposomes provide effective targeted delivery of nucleic acids into tumor cells in vitro and in xenograft tumors in vivo.