Intraperitoneal drug delivery systems releasing cytostatic agents to target gastro-intestinal peritoneal metastases in laboratory animals: a systematic review

Polymer-lipid hybrid microcarriers for oral codelivery of paclitaxel and tributyrin: development, optimization, and cytotoxicity in cells and spheroids of colorectal cancer

Colorectal cancer (CRC) is the third most frequent cancer worldwide. Despite advances in treatment, conventional chemotherapy suffers from severe side effects and limited drug selectivity, highlighting the importance of alternative therapies. In this study, a polymer-lipid hybrid microcarrier was developed for oral co-administration of paclitaxel (PTX) and tributyrin (TB) as a novel approach for CRC therapy. The microcarrier was designed with a pH-sensitive polymeric shell that encapsulates drug-loaded nanostructured lipid carriers (NLC); shell dissolution at intestinal pH enables localized release of the NLC. The methodological approach employed an emulsion of vegetable oil and NLC as a template for polymer deposition. Multiple parameters were optimized, including polymers ratios, NLC dilution, acid concentration, and sonication time. Spherical hybrid particles with smooth surface and mean size of 1000 nm were obtained; PTX encapsulation efficiency was 99.9 ± 0.2 %, with a production yield of 97.2 ± 0.08 %. Drug release followed the Korsmeyer-Peppas kinetic model. Cytotoxic evaluation in human colorectal adenocarcinoma HCT-116 monolayers showed that PTX encapsulation increased cytotoxicity, lowering IC50 to 83.7 nM compared to 199.5 nM for free PTX. The addition of TB further improved cytotoxicity, reducing the IC50 to 60.8 nM. A similar potentiation cytotoxicity was observed in spheroids. The microcarrier induced reductions in colony formation, alterations in cell cytoskeleton, and led to a significant reduction in P-glycoprotein expression compared to its free form, suggesting its potential to help to overcome drug resistance. These results point to the promising applicability of the hybrid microcarrier as an innovative delivery system for oral administration of cytotoxic agents.

Sex-specific activation of platelet purinergic signaling is key in local cytokine release and phagocytosis in the peritoneal cavity in intra-abdominal sepsis

Intra-abdominal sepsis is a life-threatening complex syndrome caused by microbes in the gut microbiota invading the peritoneal cavity. It is one of the major complications of intra-abdominal surgery. To date, only supportive therapies are available. No studies have investigated the progression of intra-abdominal sepsis in the peritoneal cavity. Our group has shown that platelets play an essential role during sepsis, and blocking purinergic signaling in platelets through P2Y1 and P2Y12 antagonism significantly lowered inflammatory levels and improved survival in a murine model of sepsis. Here, we tested whether antagonizing purinergic signaling in platelets in the peritoneal cavity can reduce the local release of cytokines and modulate platelet interaction with the immune system. We used cecal ligation and puncture (CLP) to induce sepsis followed by intraperitoneal administration of MRS2279 (P2Y1 antagonist) or ticagrelor (P2Y12 antagonist) in male and female mice. The peritoneal cavity fluid (PCF) was collected 4 or 24 h post-CLP and analyzed for cell recruitment, platelet markers, cytokines, and platelet immune cell interactions. Platelet markers were increased 24 h after CLP, although the total platelet count in the peritoneal cavity was lower than the blood. Blocking P2Y12 or P2Y1 improved bacterial clearance in the PCF in a sex-dependent manner. The influx of immune cells in the peritoneal cavity was altered by blocking P2Y12 or P2Y1 sex-dependently. Blocking P2Y1 and P2Y12 receptors can enhance the phagocytic activity in the peritoneal cavity in a sex- and time-related manner, and platelets significantly contribute to the development and progression of sepsis in the peritoneal cavity.NEW & NOTEWORTHY Intra-abdominal sepsis is a challenging complication postabdominal surgery caused by perforations of the gastrointestinal tract where microbes invade the peritoneal cavity. This leads to local cytokine release and immune cell dysfunction. Our data identify platelets as key players in mediating inflammation in intra-abdominal sepsis. We have shown that blocking purinergic signaling in the peritoneal cavity reduced cytokine release and cell-cell interactions differently in males and females, hence a sex-specific strategy to improve intra-abdominal sepsis.

Peritoneal chemotherapy delivery systems for ovarian cancer treatment: systematic review of animal models

Introduction

Intraperitoneal chemotherapy for ovarian cancer treatment has controversial benefits as most methodologies are associated with significant morbidity. We carried out a systematic review to compare tumor response, measured by tumor weight and volume, between intraperitoneal chemotherapy delivered via drug delivery systems (DDSs) and free intraperitoneal chemotherapy in animal models of ovarian cancer. The secondary aim was to assess the toxicity of DDS-delivered chemotherapy, based on changes in animal body weight.

Methods

Based on PRISMA and SYRCLE guidelines, we identified 38 studies for review, of which 20, were used in the meta-analysis. We evaluated outcome, through tumor volume and tumor weight and, toxicity, through animal weight. Analysis was based on drugs employed and treatment duration.

Results

Most studies were performed on mice. Ovarian cancer cell lines most commonly used to induce xenografts were SKOV3 (19 studies) and A2780 (6 studies). Intraperitoneal device, also known as drug delivery systems (DDS), consisted in nanoparticles, hydrogels, lipid polymer and others. The most commonly used drugs were paclitaxel and cisplatin. Most studies used as the control treatment the same chemotherapy applied free intraperitoneally and tumor response/animal weight were evaluated weekly. There was a small benefit in overall tumor reduction in animals treated with intraperitoneal chemotherapy applied through the slow release device compared with animals treated with intraperitoneal free chemotherapy, as evaluated through tumor weight - results in standardized mean difference. (-1.06; 95% CI: -1.34, -0.78) and tumor volume (-3.72; 95% CI: -4.47, -2.97), a benefit that was seen in most weekly evaluations and for most chemotherapy drugs, such as carboplatin (tumor weight: -5.60; 95% CI: -7.83, -3.37), paclitaxel (tumor weight: -1.18; 95% CI: -1.52, -0.83), and cisplatin (tumor volume: -2.85; 95% CI: -3.66, -2.04) carboplatin (tumor volume: -12.71; 95% CI: -17.35, -8.07); cisplatin (tumor volume: -7.76; 95% CI: -9.88, -5.65); paclitaxel (tumor volume: -2.85; 95% CI: -3.66, -2.04). Regarding animal weight, there was no weight reduction in animals treated with intraperitoneal chemotherapy applied through the slow-release device compared with animals treated with intraperitoneal free chemotherapy. However, significant heterogeneity was observed in some comparisons.

Conclusion

slow-release devices are overall safe and effective in animal models of ovarian cancer. It was not possible to evaluate which one is the most promising device to treat ovarian cancer, because many different types were used to apply chemotherapy intraperitoneally.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42021224573.

Intraperitoneal drug delivery systems for peritoneal carcinomatosis: Bridging the gap between research and clinical implementation

Several abdominal-located cancers develop metastasis within the peritoneum, what is called peritoneal carcinomatosis (PC), constituting a clinical challenge in their therapeutical management, often leading to poor prognoses. Current multidisciplinary strategies, including cytoreductive surgery (CRS), hyperthermic intraperitoneal chemotherapy (HIPEC), and pressurized intraperitoneal aerosol chemotherapy (PIPAC), demonstrate efficacy but have limitations. In response, alternative strategies are explored in the drug delivery field for intraperitoneal chemotherapy. Controlled drug delivery offers a promising avenue, maintaining localized drug concentrations for optimal PC management. Drug delivery systems (DDS), including hydrogels, implants, nanoparticles, and hybrid systems, show potential for sustained and region-specific drug release. The present review aims to offer an overview of the advances and current designs of DDS for PC chemotherapy administration, focusing on their composition, main characteristics, and principal experimental outcomes, highlighting the importance of biomaterial rationale design and in vitro/vivo models for their testing. Moreover, since clinical data for human subjects are scarce, we offer a critical discussion of the gap between bench and bedside in DDS translation, emphasizing the need for further research.

Development of a Supramolecular Hydrogel for Intraperitoneal Injections

Local intraperitoneal drug administration is considered a challenging drug delivery route. The therapeutic efficiency is low, mainly due to rapid clearance of drugs. To increase the intraperitoneal retention time of specific drugs, a pH-sensitive supramolecular hydrogel that can act as a drug delivery vehicle is developed. To establish the optimal formulation of the hydrogel and to study its feasibility, safety, and tissue compatibility, in vitro, postmortem, and in vivo experiments are performed. In vitro tests reveal that a hydrogelator formulation with pH ≥ 9 results in a constant viscosity of 0.1 Pa·s. After administration postmortem, the hydrogel covers the parietal and visceral peritoneum with a thin, soft layer. In the subsequent in vivo experiments, 14 healthy rats are subjected to intraperitoneal injection with the hydrogel. Fourteen and 28 days after implantation, the animals are euthanized. Intraperitoneal exposure to the hydrogel is not resulted in significant weight loss or discomfort. Moreover, no macroscopic adverse effects or signs of organ damage are detected. In several intra-abdominal tissues, vacuolated macrophages are found indicating a physiological degradation of the synthetic hydrogel. This study demonstrates that the supramolecular hydrogel is safe for intraperitoneal application and that the hydrogel shows good tissue compatibility in rats.

Evaluation of the Effect of an Intraperitoneal Cytostatic-Loaded Supramolecular Hydrogel on Intestinal Anastomotic Healing in an Animal Model

The prognosis of colorectal cancer patients with peritoneal metastases is very poor. Intraperitoneal drug delivery systems, like supramolecular hydrogels, are being developed to improve local delivery and intraperitoneal residence time of a cytostatic such as mitomycin C (MMC). In this study, we evaluate the effect of intraperitoneal hydrogel administration on anastomotic healing. Forty-two healthy Wistar rats received a colonic end-to-end anastomosis, after which 6 animals received an intraperitoneal injection with saline, 18 with unloaded hydrogel and 18 with MMC-loaded hydrogel. After 7 days, animals were euthanized, and the anastomotic adhesion and leakage score were measured as primary outcome. Secondary outcomes were bursting pressure, histological anastomosis evaluation and body weight changes. Twenty-two rats completed the follow-up period (saline: n = 6, unloaded hydrogel: n = 10, MMC-loaded hydrogel: n = 6) and were included in the analysis. A trend towards significance was found for anastomotic leakage score between the rats receiving saline and unloaded hydrogel after multiple-comparison correction (p = 0.020, α = 0.0167). No significant differences were found for all other outcomes. The main reason for drop-out in this study was intestinal blood loss. Although the preliminary results suggest that MMC-loaded or unloaded hydrogel does not influence anastomotic healing, the intestinal blood loss observed in a considerable number of animals receiving unloaded and MMC-loaded hydrogel implies that the injection of the hydrogel under the studied conditions is not safe in the current rodent model and warrants further optimalisation of the hydrogel.

Treating colorectal peritoneal metastases with an injectable cytostatic loaded supramolecular hydrogel in a rodent animal model

Patients with peritoneal metastases (PM) of colorectal cancer have a very poor outcome. Intraperitoneal delivery of chemotherapy is the preferred route for PM treatment. The main limitation of the treatment options is the short residence time of the cytostatic, with subsequent short exposure of the cancer cells. To address this, a supramolecular hydrogel has been developed that allows both local and slow release of its encapsulated drug, mitomycin C (MMC) or cholesterol-conjugated MMC (cMMC), respectively. This experimental study investigates if drug delivery using this hydrogel improves the therapeutic efficacy against PM. PM was induced in WAG/Rij rats (n = 72) by intraperitoneally injecting syngeneic colon carcinoma cells (CC531) expressing luciferase. After seven days, animals received a single intraperitoneal injection with saline (n = 8), unloaded hydrogel (n = 12), free MMC (n = 13), free cMMC (n = 13), MMC-loaded hydrogel (n = 13), or cMMC-loaded hydrogel (n = 13). Primary outcome was overall survival with a maximum follow-up of 120 days. Intraperitoneal tumor development was non-invasive monitored via bioluminescence imaging. Sixty-one rats successfully underwent all study procedures and were included to assess therapeutic efficacy. After 120 days, the overall survival in the MMC-loaded hydrogel and free MMC group was 78% and 38%, respectively. A trend toward significance was found when comparing the survival curves of the MMC-loaded hydrogel and free MMC (p = 0.087). No survival benefit was found for the cMMC-loaded hydrogel compared to free cMMC. Treating PM with our MMC-loaded hydrogel, exhibiting prolonged MMC exposure, seems effective in improving survival compared to treatment with free MMC.