Application potential of injectable hydrogels in the post-surgical window period following tumor surgery.

Chemotherapy is one of the primary modalities for the treatment of malignant diseases. The outcomes, however, are different between tumors of various origins, which hinder clinical applications. The advantages of chemotherapies in patients with hematological lesions are more obvious than those seen in solid tumors. This might be attributed to the availability of drug concentration and exposure time. Based on this phenomenon, we hypothesis that localized drug administration is expected to be more potential for solid tumors, particularly for the residual tumors in post-operative "window period". The presence of residual tumors after surgical resection are the major factors leading to tumor recurrence after surgery. The methods of dealing with this problem are yet to be found. Conventional chemotherapies are scarcely applied in the post-surgical window period due to their unselected and unexpected side effects. This article studied the advantages and disadvantages of prominent formulations currently utilized in the field of local implantation in cancer treatment, with the notable superiority of injectable hydrogel platforms being most appealing. These platforms not only enhance wound healing of the patients with less side effects, during the "window period" following tumor surgery, but also effectively eradicate residual tumors by facilitating the establishment of a favorable microenvironment. Additionally, the challenges seen in this field and future directions are discussed, which is expected to provide insights for pharmaceutical professionals and clinical applications.