Biological nanoparticles, or bionanoparticles, are small molecules manufactured in living systems with complex production and assembly machinery. The products of the assembly systems can be further engineered to generate functionalities for specific purposes. These bionanoparticles have demonstrated advantages such as immune system evasion, minimal toxicity, biocompatibility, and biological clearance. Hence, bionanoparticles are considered the new paradigm in nanoscience research for fabricating safe and effective nanoformulations for therapeutic purposes. Harnessing the power of the immune system to recognize and eradicate malignancies is a viable strategy to achieve better therapeutic outcomes with long-term protection from disease recurrence. However, cancerous tissues have evolved to become invisible to immune recognition and to transform the tumor microenvironment into an immunosuppressive dwelling, thwarting the immune defense systems and creating a hospitable atmosphere for cancer growth and progression. Thus, it is pertinent that efforts in fabricating nanoformulations for immunomodulation are mindful of the tumor-induced immune aberrations that could render cancer nanotherapy inoperable. This review systematically categorizes the immunosuppression mechanisms, the regulatory immunosuppressive cellular players, and critical suppressive molecules currently targeted as breakthrough therapies in the clinic. Finally, this review will summarize the engineering strategies for affording immune moderating functions to bionanoparticles that tip the tumor microenvironment (TME) balance toward cancer elimination, a field still in the nascent stage.

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工程生物纳米粒子作为肿瘤免疫调节的纳米疗法

生物纳米颗粒或生物纳米颗粒是在生命系统中通过复杂的生产和组装机械制造的小分子。组装系统的产品可以进一步设计以生成用于特定目的的功能。这些生物纳米颗粒具有免疫系统逃避、毒性最小、生物相容性和生物清除等优点。因此，生物纳米颗粒被认为是纳米科学研究的新范例，用于制造用于治疗目的的安全有效的纳米制剂。利用免疫系统的力量来识别和根除恶性肿瘤是一种可行的策略，可以实现更好的治疗结果并长期防止疾病复发。然而，癌组织已经进化到对免疫识别不可见，并将肿瘤微环境转变为免疫抑制住所，阻碍免疫防御系统并为癌症生长和进展创造适宜的氛围。因此，在制造用于免疫调节的纳米制剂时，必须注意肿瘤引起的免疫畸变，这些畸变可能导致癌症纳米疗法无法进行。这篇综述系统地对免疫抑制机制、调节性免疫抑制细胞参与者和目前临床突破性疗法的关键抑制分子进行了分类。最后，这篇综述将总结为生物纳米颗粒提供免疫调节功能的工程策略，从而使肿瘤微环境（TME）平衡朝着消除癌症的方向发展，而癌症这一领域仍处于起步阶段。