尽管全身免疫疗法已经在某些患者和癌症类型中实现了持久的反应和改善的生存率，但低反应率和免疫系统相关的全身毒性限制了其整体影响。肿瘤内（病灶内）免疫疗法的输送向技术是一种有前景的方法，可以对抗肿瘤微环境中的肿瘤免疫抑制机制，降低全身药物暴露和相关副作用。然而，肿瘤内注射容易出现可变的肿瘤药物分布和渗漏到周围组织中的问题，这可能损害疗效并导致毒性。控制释药系统，例如原位形成水凝胶，是解决这些挑战的有前景的载体，通过提供对局部给药免疫疗法的空间和时间控制，旨在促进全身肿瘤特异性免疫反应和阿布斯科效应。在本综述中，我们将讨论应用控制释药系统进行免疫疗法的局部输送的概念、应用和挑战，重点关注肿瘤内注射水凝胶载药系统。版权所有 © 2023. 由Elsevier B.V.出版。

Although systemic immunotherapy has achieved durable responses and improved survival for certain patients and cancer types, low response rates and immune system-related systemic toxicities limit its overall impact. Intratumoral (intralesional) delivery of immunotherapy is a promising technique to combat mechanisms of tumor immune suppression within the tumor microenvironment and reduce systemic drug exposure and associated side effects. However, intratumoral injections are prone to variable tumor drug distribution and leakage into surrounding tissues, which can compromise efficacy and contribute to toxicity. Controlled release drug delivery systems such as in situ-forming hydrogels are promising vehicles for addressing these challenges by providing improved spatio-temporal control of locally administered immunotherapies with the goal of promoting systemic tumor-specific immune responses and abscopal effects. In this review we will discuss concepts, applications, and challenges in local delivery of immunotherapy using controlled release drug delivery systems with a focus on intratumorally injected hydrogel-based drug carriers.Copyright © 2023. Published by Elsevier B.V.