Hydrogel-based drug delivery systems for localised treatment of peritoneal metastasis: A systematic and ideal framework review

The peritoneum, a membranous structure that lines the abdominal cavity, is one of the most common sites to which gastric, colorectal and ovarian cancer metastasise. The presence of peritoneal metastasis is associated with poor prognosis primarily due to the ineffectiveness of systemic therapies against this condition. Direct delivery of chemotherapy to the peritoneal cavity has been proposed as an alternative treatment, although its efficacy is limited by low drug retention. Hydrogel-based delivery solutions have the potential to augment the capabilities of intraperitoneal administration by facilitating sustained therapeutic drug concentrations via extended release. This systematic review provides a comprehensive overview of 39 preclinical studies that show improvements in therapeutic efficacy over carrier-free delivery. Synthetic hydrogels were generally favoured over hydrogels prepared from biomolecules and were largely used to administer small molecule anti-neoplastic agents over immunotherapies. An IDEAL framework analysis highlighted that whilst there is growing research interest, there has been limited clinical translation. Based on a critical analysis of the existing literature, this review offers recommendations and guidelines towards the translation of hydrogel-based drug delivery systems for the treatment of peritoneal metastasis.