Adoptive transfer of natural killer (NK) cells is becoming one of the most important parts of cancer immunotherapy. However, recent accomplishments have focused on the improvement of the targeting effects based on the engineering of chimeric antigen receptors (CARs) on cell surfaces. Despite the large quantity of therapeutic cells required for clinical applications, the technology for ex vivo expansion is not well developed. Herein, a three-dimensional (3D) engineered hyaluronic acid-based niche for cell expansion (3D-ENHANCE) is introduced. Compared with the conventional two-dimensional (2D) method, NK-92 cell lines and human EGFR-specific (CAR)–NK cells cultured in 3D-ENHANCE yield favorable mRNA expressions, elevated cytokine release, upregulated proliferative and tumor-lytic abilities, and result in enhanced antitumor efficacy. Furthermore, controllable degradation rates can be realized by tuning the formulation of 3D-ENHANCE so that it can be applied as an implantable cell reservoir at surgical sites. In vivo results with the incompletely resected MDA-MB-231 model confirm that the peri-operative implantation of 3D-ENHANCE prevents the relapse and metastases after surgery. Overall, 3D-ENHANCE presents an effective cytokine-free niche for ex vivo expansion and postsurgical treatment that enhances the low-therapeutic efficacy of human NK cells.

天然杀伤（NK）细胞的过继转移正成为癌症免疫疗法最重要的部分之一。然而，近来的成就集中在基于细胞表面上的嵌合抗原受体（CAR）的工程改造的靶向作用上。尽管临床应用需要大量治疗细胞，但离体扩增技术尚未得到很好的开发。在此，介绍了用于细胞扩增的3D（3D）工程化透明质酸基小生境（3D-ENHANCE）。与传统的二维（2D）方法相比，在3D-ENHANCE中培养的NK-92细胞系和人类EGFR特异性（CAR）–NK细胞可产生良好的mRNA表达，细胞因子释放升高，增殖和肿瘤溶解能力上调，并增强抗肿瘤功效。此外，可通过调节3D-ENHANCE的配方来实现可控制的降解速率，以便将其用作手术部位的可植入细胞储存库。使用未完全切除的MDA-MB-231模型的体内结果证实，围手术期植入3D-ENHANCE可以防止术后复发和转移。总体而言，3D-ENHANCE为离体扩增和术后治疗提供了有效的无细胞因子利基，从而增强了人类NK细胞的低治疗功效。