Chitosan/pshRNA plasmid nanoparticles targeting MDR1 gene reverse paclitaxel resistance in ovarian cancer cells

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.

Chitosan-based advanced materials for docetaxel and paclitaxel delivery: Recent advances and future directions in cancer theranostics

Paclitaxel (PTX) and docetaxel (DTX) are key members of taxanes with high anti-tumor activity against various cancer cells. These chemotherapeutic agents suffer from a number of drawbacks and it seems that low solubility in water is the most important one. Although much effort has been made in improving the bioavailability of PTX and DTX, the low bioavailability and minimal accumulation at tumor sites are still the challenges faced in PTX and DTX therapy. As a consequence, bio-based nanoparticles (NPs) have attracted much attention due to unique properties. Among them, chitosan (CS) is of interest due to its great biocompatibility. CS is a positively charged polysaccharide with the capability of interaction with negatively charged biomolecules. Besides, it can be processed into the sheet, micro/nano-particles, scaffold, and is dissolvable in mildly acidic pH similar to the pH of the tumor microenvironment. Keeping in mind the different applications of CS in the preparation of nanocarriers for delivery of PTX and DTX, in the present review, we demonstrate that how CS functionalized-nanocarriers and CS modification can be beneficial in enhancing the bioavailability of PTX and DTX, targeted delivery at tumor site, image-guided delivery and co-delivery with other anti-tumor drugs or genes.

Current strategies for different paclitaxel-loaded Nano-delivery Systems towards therapeutic applications for ovarian carcinoma: A review article

Ovarian carcinoma (OC) is one of the leading causes of death among gynecologic malignancies all over the world. It is characterized by high mortality rate because of the lack of early diagnosis. The first-line chemotherapeutic regimen for late stage epithelial ovarian cancer is paclitaxel in combination to carboplatin. However, in most of cases, relapse occurs within six months despite the initial success of this chemotherapeutic combination. A lot of challenges have been encountered with the conventional delivery of paclitaxel in addition to the occurrence of severe off-target toxicity. One major problem is poor paclitaxel solubility which was improved by addition of Cremophor EL that unfortunately resulted in hypersensitivity side effects. Another obstacle is the multi drug resistance which is the main cause of OC recurrence. Accordingly, incorporation of paclitaxel, solely or in combination to other drugs, in nanocarrier systems has grabbed attention of many researchers to circumvent all these hurdles. The current review is the first article that provides a comprehensive overview on multi-faceted implementations of paclitaxel loaded nanoplatforms to solve delivery obstacles of paclitaxel in management of ovarian carcinoma. Moreover, challenges in physicochemical properties, biological activity and targeted delivery of PTX were depicted with corresponding solutions using nanotechnology. Different categories of nanocarriers employed were collected included lipid, protein, polymeric, solid nanoemulsion and hybrid systems. Future perspectives including imperative research considerations in ovarian cancer therapy were proposed as well.

Dendritic cell engineering for selective targeting of female reproductive tract cancers

Female reproductive tract cancers (FRCs) are considered as one of the most frequently occurring malignancies and a foremost cause of death among women. The late-stage diagnosis and limited clinical effectiveness of currently available mainstay therapies, primarily due to the developed drug resistance properties of tumour cells, further increase disease severity. In the past decade, dendritic cell (DC)-based immunotherapy has shown remarkable success and appeared as a feasible therapeutic alternative to treat several malignancies, including FRCs. Importantly, the clinical efficacy of this therapy is shown to be restricted by the established immunosuppressive tumour microenvironment. However, combining nanoengineered approaches can significantly assist DCs to overcome this tumour-induced immune tolerance. The prolonged release of nanoencapsulated tumour antigens helps improve the ability of DC-based therapeutics to selectively target and remove residual tumour cells. Incorporation of surface ligands and co-adjuvants may further aid DC targeting (in vivo) to overcome the issues associated with the short DC lifespan, immunosuppression and imprecise uptake. We herein briefly discuss the necessity and progress of DC-based therapeutics in FRCs. The review also sheds lights on the future challenges to design and develop clinically effective nanoparticles-DC combinations that can induce efficient anti-tumour immune responses and prolong patients' survival.

Engineered Nanoparticles Against MDR in Cancer: The State of the Art and its Prospective

Cancer is a highly heterogeneous disease at intra/inter patient levels and known as the leading cause of death worldwide. A variety of mono and combinational therapies including chemotherapy have been evolved over the years for its effective treatment. However, advent of chemotherapeutic resistance or multidrug resistance (MDR) in cancer is a major challenge researchers are facing in cancer chemotherapy. MDR is a complex process having multifaceted non-cellular or cellular-based mechanisms. Research in the area of cancer nanotechnology over the past two decade has now proven that the smartly designed nanoparticles help in successful chemotherapy by overcoming the MDR and preferentially accumulate in the tumor region by means of active and passive targeting therefore reducing the offtarget accumulation of payload. Many of such nanoparticles are in different stages of clinical trials as nanomedicines showing promising result in cancer therapy including the resistant cases. Nanoparticles as chemotherapeutics carriers offer the opportunity to have multiple payload of drug and or imaging agents for combinational and theranostics therapy. Moreover, nanotechnology further bring in notice the new treatment strategies such as combining the NIR, MRI and HIFU in cancer chemotherapy and imaging. Here, we discussed the cellular/non-cellular factors constituting the MDR in cancer and the role of nanomedicines in effective chemotherapy of MDR cases of cancers. Moreover, recent advancements like combinational payload delivery and combined physical approach with nanotechnology in cancer therapy have also been discussed.

The role of ABC transporters in ovarian cancer progression and chemoresistance

Over 80% of ovarian cancer patients develop chemoresistance which results in a lethal course of the disease. A well-established cause of chemoresistance involves the family of ATP-binding cassette transporters, or ABC transporters that transport a wide range of substrates including metabolic products, nutrients, lipids, and drugs across extra- and intra-cellular membranes. Expressions of various ABC transporters, shown to reduce the intracellular accumulation of chemotherapy drugs, are increased following chemotherapy and impact on ovarian cancer survival. Although clinical trials to date using ABC transporter inhibitors have been disappointing, ABC transporter inhibition remains an attractive potential adjuvant to chemotherapy. A greater understanding of their physiological functions and role in ovarian cancer chemoresistance will be important for the development of more effective targeted therapies. This article will review the role of the ABC transporter family in ovarian cancer progression and chemoresistance as well as the clinical attempts used to date to reverse chemoresistance.

Evaluation of Chitosan-Tripolyphosphate Nanoparticles as a p-shRNA Delivery Vector: Formulation, Optimization and Cellular Uptake Study

Polysaccharides (especially chitosan) have recently attracted much attention as gene therapy delivery vehicles for their unique properties such as biocompatibility, biodegradability, low toxicity, and controlled release. Nanoparticles have strong potential as a carrier of plasmid short hairpin RNA (p-shRNA). This study aimed to find the optimum conditions for obtaining Chitosan/triphosphate (TPP)/p-shRNA nanoparticles by the ionic gelation method, and investigating the cellular uptake of the optimized nanoparticles. After applying the central composite design of response surface methodology (RSM), the optimum conditions for preparation of nanoparticles with small size and high loading efficiency were: chitosan/TPP ratio = 10, pH = 5.5 and N/P ratio = 11. The resulting nanoparticles had an average size of 172.8 ± 7 nm and loading efficiency of 71.5 ± 5%. SEM images showed spherical and smooth nanoparticles. The nanoparticles complexed with p-shRNA and may protect it against nuclease digestion. Cytotoxicity studies with HeLa and PC3 human cancer cells demonstrated that chitosan/TPP nanoparticles had low toxicity. Cellular uptake studies using HeLa cells showed that the nanoparticles entered the cells (cellular uptake) and delivered DNA, probably due to their favorable Zeta potential (approximately +28 mV) and small size.

Optimizing molecular-targeted therapies in ovarian cancer: the renewed surge of interest in ovarian cancer biomarkers and cell signaling pathways

The hallmarks of ovarian cancer encompass the development of resistance, disease recurrence and poor prognosis. Ovarian cancer cells express gene signatures which pose significant challenges for cancer drug development, therapeutics, prevention and management. Despite enhancements in contemporary tumor debulking surgery, tentative combination regimens and abdominal radiation which can achieve beneficial response rates, the majority of ovarian cancer patients not only experience adverse effects, but also eventually relapse. Therefore, additional therapeutic possibilities need to be explored to minimize adverse events and prolong progression-free and overall response rates in ovarian cancer patients. Currently, a revival in cancer drug discovery is devoted to identifying diagnostic and prognostic ovarian cancer biomarkers. However, the sensitivity and reliability of such biomarkers may be complicated by mutations in the BRCA1 or BRCA2 genes, diverse genetic risk factors, unidentified initiation and progression elements, molecular tumor heterogeneity and disease staging. There is thus a dire need to expand existing ovarian cancer therapies with broad-spectrum and individualized molecular targeted approaches. The aim of this review is to profile recent developments in our understanding of the interrelationships among selected ovarian tumor biomarkers, heterogeneous expression signatures and related molecular signal transduction pathways, and their translation into more efficacious targeted treatment rationales.

Nanomedicine for targeted cancer therapy: towards the overcoming of drug resistance

Anticancer drug resistance almost invariably emerges and poses major obstacles towards curative therapy of various human malignancies. In the current review we will distinguish between mechanisms of chemoresistance that are predominantly mediated by ATP-driven multidrug resistance (MDR) efflux transporters, typically of the ATP-binding cassette (ABC) superfamily, and those that are independent of such drug efflux pumps. In recent years, multiple nanoparticle (NP)-based therapeutic systems have been developed that were rationally designed to overcome drug resistance by neutralizing, evading or exploiting various drug efflux pumps and other resistance mechanisms. NPs are being exploited for selective drug delivery to tumor cells, to cancer stem/tumor initiating cells and/or to the supportive cancer cell microenvironment, i.e. stroma or tumor vasculature. Some of these NPs are currently undergoing preclinical in vivo studies as well as advanced stages of clinical evaluation with promising results. Nanovehicles harboring a payload of therapeutic drug combinations for the selective targeting and elimination of tumor cells as well as the simultaneous overcoming of mechanisms of drug resistance are a subject of intense research efforts, some of which are expected to enter clinical trials in the near future. In the present review we highlight novel approaches to selectively target cancer cells and overcome drug resistance phenomena, through the use of various nanometric drug delivery systems. In the near future, it is anticipated that innovative theragnostic nanovehicles will be developed which will harbor four major components: (1) a selective targeting moiety, (2) a diagnostic imaging aid for the localization of the malignant tumor and its micro- or macrometastases, (3) a cytotoxic, small molecule drug(s) or novel therapeutic biological(s), and (4) a chemosensitizing agent aimed at neutralizing a resistance mechanism, or exploiting a molecular "Achilles hill" of drug resistant cells. We propose to name these envisioned four element-containing nanovehicle platform, "quadrugnostic" nanomedicine. This targeted strategy holds promise in paving the way for the introduction of highly effective nanoscopic vehicles for cancer therapeutics while overcoming drug resistance.