Reducing excessive toxicity in ovarian cancer treatment: a personalized approach

A fully implantable device for intraperitoneal drug delivery refilled by ingestible capsules

Creating fully implantable robots that replace or restore physiological processes is a great challenge in medical robotics. Restoring blood glucose homeostasis in patients with type 1 diabetes is particularly interesting in this sense. Intraperitoneal insulin delivery could revolutionize type 1 diabetes treatment. At present, the intraperitoneal route is little used because it relies on accessing ports connecting intraperitoneal catheters to external reservoirs. Drug-loaded pills transported across the digestive system to refill an implantable reservoir in a minimally invasive fashion could open new possibilities in intraperitoneal delivery. Here, we describe PILLSID (PILl-refiLled implanted System for Intraperitoneal Delivery), a fully implantable robotic device refillable through ingestible magnetic pills carrying drugs. Once refilled, the device acts as a programmable microinfusion system for precise intraperitoneal delivery. The robotic device is grounded on a combination of magnetic switchable components, miniaturized mechatronic elements, a wireless powering system, and a control unit to implement the refilling and control the infusion processes. In this study, we describe the PILLSID prototyping. The device key blocks are validated as single components and within the integrated device at the preclinical level. We demonstrate that the refilling mechanism works efficiently in vivo and that the blood glucose level can be safely regulated in diabetic swine. The device weights 165 grams and is 78 millimeters by 63 millimeters by 35 millimeters, comparable with commercial implantable devices yet overcoming the urgent critical issues related to reservoir refilling and powering.

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.

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.

Local control and prognostic significance of transarterial treatment for limited recurrence of ovarian cancer as third-line and beyond therapy

BACKGROUND

We aimed to retrospectively evaluate the safety and efficacy of transarterial treatment for the recurrence of ovarian cancer, limited to one or two gross regions, in a palliative setting as third-line and beyond therapy.

METHODS

Twenty-six consecutive patients were enrolled to undergo transarterial treatment of target lesions that were life-threatening or influenced their quality of life. Transarterial infusion via each feeding artery using 20-40 mg cisplatin and 20-40 mg docetaxel per patient was repeated every 4-6 weeks. Superabsorbent polymer microspheres were added for embolization after drug infusion, especially in hepatic or pelvic treatments. Univariate and multivariate Cox's proportional hazards models were used to assess the correlations between overall survival and individual parameters.

RESULTS

A total of 63 feeding arteries (median 2 per patient; range 1-5) were treated for 36 target sites (liver, 12; pelvis, 8; abdominal cavity, 7; lymph node, 3; other, 6) at the initial treatment. Of the 128 total sessions, the only grade 3/4 toxicity was neutropenia (3.8 %). The target lesion response rate by RECIST ver.1.1 was 50.0 % (11.5 % complete response; 38.5 % partial response). After a median follow-up of 30 months, the median overall survival was 16 months. Among 10 tumor-associated symptomatic patients, 7 showed symptom improvement. Multivariate analyses shows that the only independent prognostic factor was target lesion response (hazard ratio 18.7; 95 % CI 1.9-183.4; p = 0.01).

CONCLUSIONS

Transarterial treatment for ovarian cancer achieves a high local response and good symptom control, and significantly contributes to survival for patients with local control after multiple relapses.