Sustained, low-dose intraperitoneal cisplatin improves treatment outcome in ovarian cancer mouse models

Damnacanthal isolated from morinda species inhibited ovarian cancer cell proliferation and migration through activating autophagy

BACKGROUND

Ovarian cancer is a very common gynecological malignant tumor. Natural products are important sources of chemotherapy drugs for ovarian cancer. Damnacanthal is an anthraquinone derivative with anti-cancer pharmacological properties.

OBJECTIVE

This study aimed to investigate the mechanisms underlying damnacanthal's effects against ovarian cancer.

METHODS

In vitro experiments, CCK8, colony formation and flow cytometry assays were used to evaluate the anti-ovarian cancer effect of damnacanthal on SKVO3 and A2780 cells. The wound healing tests and the transwell invasion assays were used to detect the migration and infiltration of ovarian cancer cells. Western Blot assays and immunofluorescence staining were used to measure autophagy levels. In vivo experiments, the anti-ovarian cancer effect of damnacanthal was further evaluated in a xenograft nude mouse model of SKVO3 cells.

RESULTS

Damnacanthal induced significant cell death and apoptosis, as well as significant inhibition in migration and invasion, in SKVO3 and A2780 cells, Furthermore, damnacanthal induced cell cycle arrest by increasing the protein levels of p27Kip1 and decreasing cyclin D1 levels. In addition, damnacanthal induced a significant accumulation of autophagosomes, accompanied with an increase in LC3II protein levels, and a decrease in p62 protein levels. 3-methyladenine, an autophagy formation inhibitor, significantly mitigated the damnacanthal-induced apoptosis and migration hindrance, as well as the decline in cell viability. Furthermore, the inactivation of ERK and its downstream effector mTOR signaling pathways, rather than Akt or P38 pathway, were involved in damnacanthal's activation in autophagy. In addition, TBHQ, an ERK activator, significantly inhibited damnacanthal-boosted LC3 II levels and autophagosome accumulation, and reversed damnacanthal-induced cell death, apoptosis, cell cycle arrest and migration hindrance. Finally, the anti-ovarian cancer effect of damnacanthal was confirmed in the orthotopic xenograft model of SKVO3 cells in nude mice, with tumor growth being significantly inhibited comparably to the efficacy of cisplatin. Damnacanthal was also synergistic with cisplatin and showed inhibition in cisplatin-resistant ovarian cancer cells.

CONCLUSION

Damnacanthal inhibited the growth of ovarian cancer via the ERK/mTOR/autophagy signaling cascade, indicating that it may be a potential anti-ovarian cancer drug candidate.

Differential Drug Release Kinetics from Paclitaxel-Loaded Polydioxanone Membranes and Capsules

BACKGROUND

Drug laden implantable systems can provide drug release over several hours to years, which eventually aid in the therapy of both acute and chronic diseases. The present study focuses on a fundamental evaluation of the influence of implant properties such as morphology, architecture, porosity, surface area, and wettability in regulating the drug release kinetics from drug-loaded polymeric matrices.

METHODS

For this, Polydioxanone (PDS) was selected as the polymer and Paclitaxel (Ptx) as the model drug. Two different forms of the matrix implants, viz., reservoir type capsules developed by dip coating and matrix type membranes fabricated by phase inversion and electrospinning, were utilized for the study. Drug release from all the four different matrices prepared by simple techniques was evaluated in vitro in PBS and ex vivo in peritoneal wash fluid for ~4 weeks. The drug release profiles were thereafter correlated with the physicochemical parameters of the polymeric implants.

RESULTS

Reservoir-type capsules followed a slow and steady zero-order kinetics, while matrix-type electrospun and phase inversion membranes displayed typical biphasic kinetics.

CONCLUSION

It was inferred that the slow degradation rate of PDS polymer as well as the implant properties like porosity and wettability play an important role in controlling the drug release rates.

Prolonged activity of a recombinant manganese superoxide dismutase through a formulation of polymeric multi-layer nanoassemblies targeting cancer cells

A new isoform of human manganese superoxide dismutase (SOD) has been recently isolated and obtained in a synthetic recombinant form and termed rMnSOD. As compared to other SODs, this isoform exhibits a dramatically improved cellular uptake and an intense antioxidant and antitumoral activity. Unfortunately, its use is severely hampered as this active pharmaceutical ingredient (API) in solution suffers from remarkable instability, which realizes as an interplay of unfolding and aggregation phenomena. This leads the API to be ineffective after three weeks only when stored at 4°C. A formulation strategy was undertaken to mitigate this instability. This was based on the incorporation of the API in hyaluronic acid and its layer-by-layer deposition over a chitosan-n-acetyl cysteine- monolayer nanoemulsion (NE) and its subsequent coverage with a further external interface of a chitosan-n-acetyl cysteine. The obtained constructs were tested over a selected panel of healthy and cancerous cell lines. The undertaken formulation strategy enhanced the API's effect in vitro already at time zero, maintaining the efficacy of this anticancer agent until up to 30 weeks when stored at 4°C.

Pharmaceutical strategies in improving anti-tumour efficacy and safety of intraperitoneal therapy for peritoneal metastasis

Introduction: In selected patients with limited peritoneal metastasis (PM), favorable tumor biology, and a good clinical condition, there is an indication for combination of cytoreductive surgery (CRS) and subsequent intravenous (IV) or intraperitoneal (IP) chemotherapy. Compared with IV injection, IP therapy can achieve a high drug concentration within the peritoneal cavity with low systemic toxicity, however, the clinical application of IP chemotherapy is limited by the related abdominal pain, infection, and intolerance.Areas covered:To improve the anti-tumor efficacy and safety of IP therapy, various pharmaceutical strategies have been developed and show promising potential. This review discusses the specialized modification of traditional drug delivery systems and demonstrates the preparation of customized drug carriers for IP therapy, including chemotherapy and gene therapy. IP therapy has important clinical significance in the treatment of PM using novel anti-tumor agents as well as conventional drugs in new applications.Expert opinion: Although IP therapy exhibits good performance both in mouse models and in patients with PM in clinical trials, its clinical application remains limited due to the serious side effects and low acceptability. Further investigations, including pharmaceutical strategies, are needed to develop potential IP therapy, focusing on the efficacy and safety thereof.

Enhancing delivery of small molecule and cell-based therapies for ovarian cancer using advanced delivery strategies

Ovarian cancer is the most lethal gynecological malignancy with a global five-year survival rate of 30-50%. First-line treatment involves cytoreductive surgery and administration of platinum-based small molecules and paclitaxel. These therapies were traditionally administered via intravenous infusion, although intraperitoneal delivery has also been investigated. Initial clinical trials of intraperitoneal administration for ovarian cancer indicated significant improvements in overall survival compared to intravenous delivery, but this result is not consistent across all studies performed. Recently cell-based immunotherapy has been of interest for ovarian cancer. Direct intraperitoneal delivery of cell-based immunotherapies might prompt local immunoregulatory mechanisms to act synergistically with the delivered immunotherapy. Based on this theory, pre-clinical in vivo studies have delivered these cell-based immunotherapies via the intraperitoneal route, with promising results. However, successful intraperitoneal delivery of cell-based immunotherapy and clinical adoption of this technique will depend on overcoming challenges of intraperitoneal delivery and finding the optimal combinations of dose, therapeutic and delivery route. We review the potential advantages and disadvantages of intraperitoneal delivery of cell-based immunotherapy for ovarian cancer and the pre-clinical and clinical work performed so far. Potential advanced delivery strategies, which might improve the efficacy and adoption of intraperitoneal delivery of therapy for ovarian cancer, are also outlined.

Nanofibrous Polydioxanone Depots for Prolonged Intraperitoneal Paclitaxel Delivery

BACKGROUND

Prolonged chemodrug delivery to the tumor site is a prerequisite to maintaining its localised therapeutic concentrations for effective treatment of malignant solid tumors.

OBJECTIVE

The current study aims to develop implantable polymeric depots through conventional electrospinning for sustained drug delivery, specifically to the peritoneum.

METHODS

Non-woven electrospun mats were fabricated by simple electrospinning of Polydioxanone solution loaded with the chemodrug, Paclitaxel. The implants were subjected to the analysis of morphology, mechanical properties, degradation and drug release in phosphate buffer and patient-derived peritoneal drain fluid samples. In vivo studies were conducted by surgical knotting of these implants to the peritoneal wall of healthy mice.

RESULTS

Non-woven electrospun mats with a thickness of 0.65±0.07 mm, weighing ~ 20 mg were fabricated by electrospinning 15 w/v% polymer loaded with 10 w/w% drug. These implants possessing good mechanical integrity showed a drug entrapment efficiency of 87.82±2.54 %. In vitro drug release studies in phosphate buffer showed a sustained profile for ~4 weeks with a burst of 10 % of total drug content, whereas this amounted to >60% in patient samples. Mice implanted with these depots remained healthy during the study period. The biphasic drug release profile obtained in vivo showed a slow trend, with peritoneal lavage and tissues retaining good drug concentrations for a sustained period.

CONCLUSION

The results indicate that non-woven electrospun mats developed from biodegradable Polydioxanone polymer can serve as ideal candidates for easily implantable drug depots to address the challenges of peritoneal metastasis in ovarian cancer.

Enhanced anti-tumor efficacy and safety with metronomic intraperitoneal chemotherapy for metastatic ovarian cancer using biodegradable nanotextile implants

The objective of this study was to evaluate intraperitoneal (IP) metronomic chemotherapy using sustained release paclitaxel (PTX) delivery from electrospun biodegradable polymeric yarns woven into suturable nanotextiles. Following confirmation of in vitro PTX efficacy in ID8-VEGF epithelial ovarian cancer cells, in vivo studies were performed upon surgical peritoneal implantation of nanotextile implants in orthotopic, syngeneic ID8-VEGF tumor-bearing C57BL/6 mice. In comparison to the clinical PTX-solution, there was a significant enhancement of anti-tumor efficacy and safety with PTX-nanotextiles. After 35-days, the peritoneum of tumor-bearing mice with PTX-nanotextiles was completely devoid of tumor nodules and ascitic fluid. Additionally, VEGF levels measured in peritoneal lavage fluid were 300-fold lower compared to PTX-solution and 600-fold lower as compared to untreated tumor-bearing animals. PTX-solution treated group also developed severe metastatic lesions and progressive ascitic fluid buildup. More importantly, no signs of systemic/ organ toxicity were observed in PTX-nanotextile implanted mice, unlike the systemic toxic effects induced by PTX-solution. Collectively, our results show the therapeutic and safety advantages offered by combining clinically translatable metronomic low-dose chemotherapy and IP pharmacokinetics using biodegradable nanotextile implants in addressing the challenges of late-stage ovarian cancer.

Rethinking Alkylating(-Like) Agents for Solid Tumor Management

Although old molecules, alkylating agents and platinum derivatives are still widely used in the treatment of various solid tumors. However, systemic toxicity and cellular resistance mechanisms impede their efficacy. Innovative strategies, including local administration, optimization of treatment schedule/dosage, synergistic combinations, and the encapsulation of bioactive molecules in smart, multifunctional drug delivery systems, have shown promising results in potentiating anticancer activity while circumventing such hurdles. Furthermore, questioning of the old paradigm according to which nuclear DNA is the critical target of their anticancer activity has shed light on subcellular alternative and neglected targets that obviously participate in the mediation of cytotoxicity or resistance. Thus, rethinking of the use of these pivotal antineoplastic agents appears critical to improve clinical outcomes in the management of solid tumors.

Long-term drug delivery using implantable electrospun woven polymeric nanotextiles

A woven nanotextile implant was developed and optimized for long-term continuous drug delivery for potential oncological applications. Electrospun polydioxanone (PDS) nanoyarns, which are twisted bundles of PDS nanofibres, were loaded with paclitaxel (PTX) and woven into nanotextiles of different packing densities. A mechanistic modeling of in vitro drug release proved that a combination of diffusion and matrix degradation controlled the slow PTX-release from a nanoyarn, emphasizing the role of nanostructure in modulating release kinetics. Woven nanotextiles, through variations in its packing density and thereby architecture, demonstrated tuneable PTX-release. In vivo PTX-release, pharmacokinetics and biodistribution were evaluated in healthy BALB/c mice by suturing the nanotextile to peritoneal wall. The slow and metronomic PTX-release for 60 days from the loosely woven implant was extremely effective in enhancing its residence in peritoneum, in contrast to intraperitoneal injections. Such an implantable matrix offers a novel platform for therapy of solid tumors over prolonged durations.

Addition of intraperitoneal cisplatin and etoposide to first-line chemotherapy for advanced ovarian cancer: a randomised, phase 2 trial

BACKGROUND

We assessed the efficacy of adding intraperitoneal (IP) chemotherapy to standard first-line intravenous (IV) chemotherapy in epithelial ovarian cancer (EOC) patients.

METHODS

Patients with stage IIIC-IV EOC who underwent optimal debulking surgery were randomly assigned to four cycles of weekly IP chemotherapy with cisplatin (50 mg/m²) and etoposide (100 mg/m²) followed by six cycles of IV chemotherapy every 3 weeks (IP/IV arm), or were administered IV chemotherapy alone (IV arm). The primary endpoint for this study was the 12-month non-progression rate (NPR).

RESULTS

Between 4/2009 and 9/2015, 218 patients were randomised, of whom 215 initiated treatment. In the IP/IV arm, 90.6% of patients completed 4 cycles of IP chemotherapy. The 12-month NPRs were 81.9% and 64.2% in the IP/IV and IV groups, respectively (HR 0.48 (95% CI 0.27-0.82)). The median progression-free survival (PFS) was increased in the IP/IV arm compared with that in the IV arm (22.4 vs. 16.8 months; HR 0.66 (0.48-0.91)) and in a subgroup with no gross cytoreduction (31.1 vs. 16.8 months; HR 0.46 (0.26-0.82)). Similar findings were detected with regard to time to first subsequent anticancer therapy (TFST) (25.9 vs. 18.0 months; P = 0.009) and time to second subsequent anticancer therapy (TSST) (40.8 vs. 30.1 months; P = 0.042). Grade 3/4 leukopenia, anaemia and gastrointestinal events were more common in the IP/IV arm, but the treatment burden was considered acceptable.

CONCLUSIONS

IP chemotherapy prior to IV chemotherapy was associated with an increased 12-month NPR and a longer TSST than IV alone in patients with EOC, albeit with acceptable toxic effects. Long-term follow-up is warranted to identify the effects of IP therapy on overall survival.

Intraperitoneal chemotherapy for ovarian cancer using sustained-release implantable devices

INTRODUCTION

Epithelial ovarian cancer (EOC) remains to be the most lethal of all gynecological malignancies mainly due to its asymptomatic nature. The late stages are manifested with predominant metastases confined to the peritoneal cavity. Although there has been a substantial progress in the treatment avenue with different therapeutic interventions, the overall survival rate of patients remain poor due to relapse and drug resistance.

AREAS COVERED

The pharmacokinetic advantages offered by intraperitoneal (IP) chemotherapy due to peritoneal-plasma barrier can be potentially exploited for EOC relapse treatment. The ability to retain high concentrations of chemo-drugs with high AUC peritoneum/plasma for prolonged durations in the peritoneal cavity can be utilized effectively through the clinical adoption of drug delivery systems (DDSs) which obviates the need for indwelling catheters. The metronomic dosing strategy could enhance anti-tumor efficacy with a continuous, low dose of chemo-drugs providing minimal systemic toxicity.

EXPERT OPINION

The development of a feasible, non-catheter based, IP DDS, retaining the peritoneal-drug levels, with less systemic levels could offer significant survival advantages as a patient-compliant therapeutic strategy. Suturable-implantable devices based on metronomic dosing, eluting drug in a sustained manner at low doses, could be implanted surgically post-debulking for treatment of refractory EOC patients.

Modelling drug transport during intraperitoneal chemotherapy

Despite a strong rationale for intraperitoneal (IP) chemotherapy, the actual use of the procedure is limited by the poor penetration depth of the drug into the tissue. Drug penetration into solid tumours is a complex mass transport process that involves multiple parameters not only related to the used cytotoxic agent but also to the tumour tissue properties and even the therapeutic setup. Mathematical modelling can provide unique insights into the different transport barriers that occur during IP chemotherapy as well as offer the possibility to test different protocols or drugs without the need for in vivo experiments. In this work, a distinction is made between three different types of model: the lumped parameter model, the distributed model and the cell-based model. For each model, we discuss which steps of the transport process are included and where assumptions are made. Finally, we focus on the advantages and main limitations of each category and discuss some future perspectives for the modelling of IP chemotherapy.

Improving paclitaxel pharmacokinetics by using tumor-specific mesoporous silica nanoparticles with intraperitoneal delivery

Mesoporous silica nanoparticles (MSNs) containing paclitaxel for intraperitoneal (i.p.) delivery were developed to exploit the tumor specific accumulation of these nanocarriers after i.p. injection and the slow release of paclitaxel from the MSNs. A 3.5-fold increase in tumor cellular drug uptake was observed for the paclitaxel-loaded MSNs compared with free paclitaxel. An in vivo study using xenograft mice bearing peritoneal human pancreatic carcinoma MIA PaCa-2 demonstrated that the MSN-paclitaxel formulation, compared to free paclitaxel, exhibited a 3.2-fold increase in peritoneal cavity residence time, slower absorption into the systemic circulation with one third systemic exposure, but a 6.5-fold increase in peritoneal tumor accumulation. Tissue distribution imaging showed significantly greater accumulation of fluorescent MSNs in tumor tissues compared to other peritoneal tissues. In conclusion, intraperitoneal administration of drug-containing MSNs was effective at reducing systemic exposure and increasing the peritoneal tumor accumulation of paclitaxel.