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

A Comprehensive Review on Current Treatments and Challenges Involved in the Treatment of Ovarian Cancer

Ovarian cancer (OC) is the second most common gynaecological malignancy. It typically affects females over the age of 50, and since 75% of cases are only discovered at stage III or IV, this is a sign of a poor diagnosis. Despite intraperitoneal chemotherapy's chemosensitivity, most patients relapse and face death. Early detection is difficult, but treatment is also difficult due to the route of administration, resistance to therapy with recurrence, and the need for precise cancer targeting to minimize cytotoxicity and adverse effects. On the other hand, undergoing debulking surgery becomes challenging, and therapy with many chemotherapeutic medications has manifested resistance, a condition known as multidrug resistance (MDR). Although there are other therapeutic options for ovarian cancer, this article solely focuses on co-delivery techniques, which work via diverse pathways to overcome cancer cell resistance. Different pathways contribute to MDR development in ovarian cancer; however, usually, pump and non-pump mechanisms are involved. Striking cancerous cells from several angles is important to defeat MDR. Nanocarriers are known to bypass the drug efflux pump found on cellular membranes to hit the pump mechanism. Nanocarriers aid in the treatment of ovarian cancer by enhancing the delivery of chemotherapeutic drugs to the tumour sites through passive or active targeting, thereby reducing unfavorable side effects on the healthy tissues. Additionally, the enhanced permeability and retention (EPR) mechanism boosts the bioavailability of the tumour site. To address the shortcomings of conventional delivery, the current review attempts to explain the current conventional treatment with special reference to passively and actively targeted drug delivery systems (DDSs) towards specific receptors developed to treat ovarian cancer. In conclusion, tailored nanocarriers would optimize medication delivery into the intracellular compartment before optimizing intra-tumour distribution. Other novel treatment possibilities for ovarian cancer include tumour vaccines, gene therapy, targeting epigenetic alteration, and biologically targeted compounds. These characteristics might enhance the therapeutic efficacy.

Engineering extracellular vesicles mimetics for targeted chemotherapy of drug-resistant ovary cancer

Aim: To develop nanocarriers for targeting the delivery of chemotherapeutics to overcome multidrug-resistant ovarian cancer. Materials & methods: Doxorubicin-loaded nanovesicles were obtained through serial extrusion, followed by loading of P-glycoprotein siRNA and folic acid. The targeting ability and anticancer efficacy of the nanovesicles were evaluated. Results: The doxorubicin-loaded nanovesicles showed a high production yield. The presence of P-glycoprotein siRNA and folic acid resulted in reversed drug resistance and tumor targeting. This nanoplatform tremendously inhibited the viability of multidrug-resistant ovarian cancer cells, which was able to target tumor tissue and suppress tumor growth without adverse effects. Conclusion: These bioengineered nanovesicles could serve as novel extracellular vesicles mimetics for chemotherapeutics delivery to overcome multidrug resistance.

mPEG-PDLLA Micelles Potentiate Docetaxel for Intraperitoneal Chemotherapy in Ovarian Cancer Peritoneal Metastasis

Ovarian cancer is the second most common cause of gynecological cancer death in women. It is usually diagnosed late and accompanied by peritoneal metastasis. For ovarian cancer with peritoneal metastasis, intraperitoneal (IP) chemotherapy can maintain a high drug concentration in the abdominal cavity and reduce local and systemic toxicity. Recently, docetaxel (DTX) has shown broad-spectrum antitumor activity against various malignant tumors, including ovarian cancer with peritoneal metastasis. However, DTX has limited clinical applications due to its poor water solubility, predisposition to hypersensitivity, fluid retention, and varying degrees of neurotoxicity. In this study, we prepared methoxy-poly(ethylene glycol)-block-poly(D,L-lactide) (mPEG-PDLLA) micelles loaded with DTX and developed an alternative, less toxic, more effective DTX formulation, without Tween 80, and evaluated its pharmacokinetics in the abdominal cavity and its efficacy in ovarian cancer with peritoneal metastasis. The mean diameter of DTX-mPEG-PDLLA was about 25 nm, and the pharmacokinetics of BALB/c mice via IP showed that the plasma exposure of DTX-mPEG-PDLLA was about four times lower than that of DTX. Importantly, DTX-mPEG-PDLLA was significantly more effective than DTX and prolonged the survival period in a SKOV-3 ovarian cancer peritoneal metastasis model. Moreover, the apoptosis rate was significantly increased in vitro. Based on these findings, it is expected that DTX-mPEG-PDLLA can enhance efficacy against ovarian cancer peritoneal metastasis, while reducing toxic side effects, and has the potential to be used in the clinical treatment of peritoneal metastatic cancer.

Synthesis of nanomedicine hydrogel microcapsules by droplet microfluidic process and their pH and temperature dependent release

Chitosan and alginate hydrogels are attractive because they are highly biocompatible and suitable for developing nanomedicine microcapsules. Here we fabricated a polydimethylsiloxane-based droplet microfluidic reactor to synthesize nanomedicine hydrogel microcapsules using Au@CoFeB-Rg3 as a nanomedicine model and a mixture of sodium alginate and PEG-g-chitosan crosslinked by genipin as a hydrogel model. The release kinetics of nanomedicines from the hydrogel were evaluated by simulating the pH and temperature of the digestive tract during drug transport and those of the target pathological cell microenvironment. Their pH and temperature-dependent release kinetics were studied by measuring the mass loss of small pieces of thin films formed by the nanomedicine-encapsulating hydrogels in buffers of pH 1.2, 7.4, and 5.5, which replicate the pH of the stomach, gut and blood, and cancer microenvironment, respectively, at 20 °C and 37 °C, corresponding to the storage temperature of hydrogels before use and normal body temperature. Interestingly, nanomedicine-encapsulating hydrogels can undergo rapid decomposition at pH 5.5 and are relatively stable at pH 7.4 at 37 °C, which are desirable qualities for drug delivery, controlled release, and residue elimination after achieving target effects. These results indicate that the designed nanomedicine hydrogel microcapsule system is suitable for oral administration.

Engineered strategies to enhance tumor penetration of drug-loaded nanoparticles

Nanocarriers have been widely employed in preclinical studies and clinical trials for the delivery of anticancer drugs. The most important causes of failure in clinical translation of nanocarriers is their inefficient accumulation and penetration which arises from special characteristics of tumor microenvironment such as insufficient blood supply, dense extracellular matrix, and elevated interstitial fluid pressure. Various strategies such as engineering extracellular matrix, optimizing the physicochemical properties of nanocarriers have been proposed to increase the depth of tumor penetration; however, these strategies have not been very successful so far. Novel strategies such as transformable nanocarriers, transcellular transport of peptide-modified nanocarriers, and bio-inspired carriers have recently been emerged as an advanced generation of drug carriers. In this study, the latest developments of nanocarrier-based drug delivery to solid tumor are presented with their possible limitations. Then, the prospects of advanced drug delivery systems are discussed in detail.

Self-Therapeutic Cobalt Hydroxide Nanosheets (Co(OH)2 NS) for Ovarian Cancer Therapy

High-grade serous ovarian cancer (HGSOC) is one of the major life-threatening cancers in women, with a survival rate of less than 50%. So far, chemotherapy is the main therapeutic tool to cure this lethal disease; however, in many cases, it fails to cure HGSOC even with severe side effects. Self-therapeutic nanomaterials could be an effective alternative to chemotherapy, facilitated by their diverse physicochemical properties and the ability to generate reactive species for killing cancer cells. Herein, inorganic cobalt hydroxide nanosheets (Co(OH)₂ NS) were synthesized by a simple solution process at room temperature, and morphological, spectroscopic, and crystallographic analyses revealed the formation of Co(OH)₂ NS with good crystallinity and purity. The as-prepared Co(OH)₂ NS showed excellent potency, comparable to the FDA-approved cisplatin drug to kill ovarian cancer cells. Flow cytometric analysis (nnexin V) revealed increased cellular apoptosis for Co(OH)₂ NS than cobalt acetate (the precursor). Tracking experiments demonstrated that Co(OH)₂ NS are internalized through the lysosome pathway, although relocalization in the cytoplasm has been observed. Hence, Co(OH)₂ NS could be an effective self-therapeutic drug and open up an area for the optimization of self-therapeutic properties of cobalt nanomaterials for cancer treatment.

Star polyester-based folate acid-targeting nanoparticles for doxorubicin and curcumin co-delivery to combat multidrug-resistant breast cancer

Chemotherapeutic treatments are indispensable in the treatment of breast cancer. However, the emergence of multidrug-resistance, strong cell toxicity, and poor targeting selection has inhibited their clinical application. In this study, two synergistic drugs, doxorubicin (DOX) and curcumin (CUR), were co-administered to overcome multidrug resistance (MDR). Based on the characteristics of the tumor microenvironment, we developed folic acid-modified nanoparticles ((DOX + CUR)-FA-NPs) based on a star-shaped polyester (FA-TRI-CL) to enhance the tumor targeting selectivity and drug loading (DL) capacity. The (DOX + CUR)-FA-NPs displayed a characteristic spheroid morphology with an ideal diameter (186.52 nm), polydispersity index (0.024), zeta potential (-18.87 mV), and good entrapment efficiency (97.64%/78.13%, DOX/CUR) and DL (20.27%/11.29%, DOX/CUR) values. In vitro pharmacokinetic and pharmacodynamic experiments demonstrated that the (DOX + CUR)-FA-NPs were gradually released, and they displayed the highest cell apoptosis and cellular uptake in MCF-7/ADR cells. Additionally, in vivo results illustrated that (DOX + CUR)-FA-NPs not only displayed significant tumor targeting and anticancer efficacy, but also induced less pathological damage to the normal tissue. In summary, co-administered DOX and CUR appeared to reverse MDR, and this targeted combinational nanoscale delivery system could thus be a promising carrier for tumor therapies in the future.

Long non-coding RNA SDCBP2-AS1 delays the progression of ovarian cancer via microRNA-100-5p-targeted EPDR1

Background

Dysregulation of long non-coding RNAs has been implied to connect with cancer progression. This research was to decipher the mechanism of long non-coding RNA SDCBP2-AS1 in ovarian cancer (OC) through regulation of microRNA (miR)-100-5p and ependymin-related protein 1 (EPDR1).

Methods

LncRNA SDCBP2-AS1 and EPDR1 levels in OC were assessed by Gene Expression Profiling Interactive Analysis. lncRNA SDCBP2-AS1, miR-100-5p, and EPDR1 levels in OC tissues and cells were determined. SKOV3 and A2780 cells were transfected with lncRNA SDCBP2-AS1, miR-100-5p, and EPDR1-related plasmids or sequences, and then their functions in cell viability, apoptosis, migration, and invasion were evaluated. The interplay of lncRNA SDCBP2-AS1, miR-100-5p, and EPDR1 was clarified.

Results

LncRNA SDCBP2-AS1 and EPDR1 levels were suppressed whilst miR-100-5p level was elevated in OC. After upregulating lncRNA SDCBP2-AS1 or EPDR1, viability, migration, and invasion of OC cells were impaired, and apoptosis rate was increased. Downregulating EPDR1 or upregulating miR-100-5p partially mitigated upregulated lncRNA SDCBP2-AS1-induced impacts on the biological functions of OC cells. LncRNA SDCBP2-AS1 sponged miR-100-5p, and EPDR1 was targeted by miR-100-5p.

Conclusion

It is illustrated that lncRNA SDCBP2-AS1 regulates EPDR1 by sponge adsorption of miR-100-5p to inhibit the progression of OC.

Perspectives in Breast and Ovarian Cancer Chemotherapy by Nanomedicine Approach: Nanoformulations in Clinical Research

BACKGROUND

Breast and ovarian carcinomas represent major health problems in women worldwide. Chemotherapy constitutes the main treatment strategy, and the use of nanocarriers, a good tool to improve it. Several nanoformulations have already been approved, and others are under clinical trials for the treatment of both types of cancers.

OBJECTIVE

This review focuses on the analysis of the nanoformulations that are under clinical research in the treatment of these neoplasms.

RESULTS

Currently, there are 6 nanoformulations in clinical trials for breast and ovarian carcinomas, most of them in phase II and phase III. In the case of breast cancer treatment, these nanomedicines contain paclitaxel; and, for ovarian cancer, nanoformulations containing paclitaxel or camptothecin analogs are being evaluated. The nanoencapsulation of these antineoplastics facilitates their administration and reduces their systemic toxicity. Nevertheless, the final approval and commercialization of nanoformulations may be limited by other aspects like lack of correlation between the efficacy results evaluated at in vitro and in vivo levels, difficulty in producing large batches of nanoformulations in a reproducible manner and high production costs compared to conventional formulations of antineoplastics. However, these challenges are not insurmountable and the number of approved nanoformulations for cancer therapy is growing.

CONCLUSION

Reviewed nanoformulations have shown, in general, excellent results, demonstrating a good safety profile, a higher maximum tolerated dose and a similar or even slightly better antitumor efficacy compared to the administration of free drugs, reinforcing the use of nano-chemotherapy in both breast and ovarian tumors.

Visible Light-Activated Water-Soluble Platicur Nanocolloids: Photocytotoxicity and Metabolomics Studies in Cancer Cells

Nanoparticle-based drug delivery systems for cancer therapy offer a great promising opportunity as they specifically target cancer cells, also increasing the bioavailability of anticancer drugs characterized by low water solubility. Platicur, [Pt(cur) (NH₃)₂](NO₃), is a cis-diamine-platinum(II) complex linked to curcumin. In this work, an ultrasonication method, coupled with layer by layer technology, allows us to obtain highly aqueous stable Platicur nanocolloids of about 100 nm. The visible light-activated Platicur nanocolloids showed an increased drug release and antitumor activity on HeLa cells, with respect to Platicur nanocolloids in darkness. This occurrence could give very interesting insight into selective activation of the nanodelivered Pt(II) complex and possible side-effect lowering. For the first time, the metabolic effects of Platicur nanocolloid photoactivation, in the HeLa cell line, have been investigated using an NMR-based metabolomics approach coupled with statistical multivariate data analysis. The reported results highlight specific metabolic differences between photoactivated and non-photoactivated Platicur NC-treated HeLa cancer cells.

Cisplatin-loaded albumin nanoparticle and study their internalization effect by using β-cyclodextrin

The present study with aim at enhancing the therapeutic and anti-cancer properties of cisplatin (CPT)-loaded bovine serum albumin (BSA) nanoparticles. The BSA nanoparticles containing CPT (CPT-BSANPs) were successfully prepared by the desolvation technique. The physicochemical characterization of the CPT-BSANPs were used by Fourier transformed infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and atomic force microscopy (AFM). The particle size of CPT-BSANPs was found less than 200 nm with 75.02 ± 0.15% entrapment efficiency (EE), while zeta potential and PDI were -17.6 mV and 0.2, respectively. In vitro release behavior of the CPT from the carrier suggests that about 64% of the drug gets released after 48 hrs. The anti-cancer activities of the CPT-BSANPs were tested on MCF-7 cell lines. Our studies show that CPT-BSANPs nanoparticles showed specific targeting and enhanced cytotoxicity to MCF-7 cells when compared to the bare CPT. Thus results suggest that CPT-BSANPs fallowed caveolae-mediated endocytosis, it may become better option for intracellular delivery of anticancer drug.

PLGA Nanoparticles for the Intraperitoneal Administration of CBD in the Treatment of Ovarian Cancer: In Vitro and In Ovo Assessment

The intraperitoneal administration of chemotherapeutics has emerged as a potential route in ovarian cancer treatment. Nanoparticles as carriers for these agents could be interesting by increasing the retention of chemotherapeutics within the peritoneal cavity. Moreover, nanoparticles could be internalised by cancer cells and let the drug release near the biological target, which could increase the anticancer efficacy. Cannabidiol (CBD), the main nonpsychotropic cannabinoid, appears as a potential anticancer drug. The aim of this work was to develop polymer nanoparticles as CBD carriers capable of being internalised by ovarian cancer cells. The drug-loaded nanoparticles (CBD-NPs) exhibited a spherical shape, a particle size around 240 nm and a negative zeta potential (-16.6 ± 1.2 mV). The encapsulation efficiency was high, with values above 95%. A controlled CBD release for 96 h was achieved. Nanoparticle internalisation in SKOV-3 epithelial ovarian cancer cells mainly occurred between 2 and 4 h of incubation. CBD antiproliferative activity in ovarian cancer cells was preserved after encapsulation. In fact, CBD-NPs showed a lower IC₅₀ values than CBD in solution. Both CBD in solution and CBD-NPs induced the expression of PARP, indicating the onset of apoptosis. In SKOV-3-derived tumours formed in the chick embryo model, a slightly higher-although not statistically significant-tumour growth inhibition was observed with CBD-NPs compared to CBD in solution. To sum up, poly-lactic-co-glycolic acid (PLGA) nanoparticles could be a good strategy to deliver CBD intraperitoneally for ovarian cancer treatment.

Enhanced docetaxel delivery using sterically stabilized RIPL peptide-conjugated nanostructured lipid carriers: In vitro and in vivo antitumor efficacy against SKOV3 ovarian cancer cells

Docetaxel (DTX) has poor solubility, low specificity, and severe side effects. For efficient targeting of DTX to hepsin-overexpressing SKOV3 ovarian cancer cells, PEGylated and RIPL peptide (IPLVVPLRRRRRRRRC)-conjugated nanostructured lipid carriers (PEG-RIPL-NLCs) were examined for in vitro and in vivo antitumor efficacy. DTX-loaded plain NLCs (DTX-pNLCs), RIPL-NLCs (DTX-RIPL-NLCs), and PEG-RIPL-NLCs (DTX-PEG-RIPL-NLCs) were prepared using a solvent emulsification-evaporation technique. DTX was successfully loaded with high encapsulation efficiency (>93%), and all NLCs showed homogeneous dispersion with zeta potentials varying from -17 to 15 mV. Drug release was biphasic: initial rapid release, then gradual release. In vitro cytotoxicity was time- and dose-dependent: DTX-RIPL-NLCs and DTX-PEG-RIPL-NLCs exhibited greater cytotoxicity, enhanced cell apoptosis owing to the cell cycle arrest in the G2/M phase, and increased activation of the mitochondria-related intrinsic apoptosis pathway compared to DTX-pNLCs. Pharmacokinetic experiments in male Sprague-Dawley rats revealed that DTX-PEG-RIPL-NLCs increased the mean residence time of DTX but reduced total body clearance and volume of distribution. In a SKOV3-bearing xenograft Balb/c athymic mouse model, DTX-PEG-RIPL-NLCs suppressed tumors, evidenced by tumor volume change and histopathological examination. Thus, we conclude that PEG-RIPL-NLCs have an advantage of high payload of poorly water-soluble drugs and are a good candidate for drug targeting to SKOV3-derived ovarian cancer.