Department of Surgery, Drexel University College of Medicine, Philadelphia, PA, 19102, USA.
Department of Materials Science and Engineering, Drexel University, Philadelphia, PA, USA.
Ann Surg Oncol. 2020 Jan;27(1):76-84. doi: 10.1245/s10434-019-07493-7. Epub 2019 Jun 11.
Treatment failure in pseudomyxoma peritonei (PMP) is partly attributed to the ineffective delivery of therapeutics through dense mucinous tumor barriers. We modified the surface of Poly (lactic-co-glycolic acid)-b-polyethylene glycol (PLGA-PEG-NPs) with a low-density, second PEG layer (PLGA-TPEG-NPs-20) to reduce their binding affinity to proteins and improve diffusion through mucin.
Nanoprecipitation was used to fabricate PLGA-PEG-NPs. To construct the second PEG layer of PLGA-TPEG-NPs-20, PEG-Thiol was conjugated to PLGA-PEG-NPs composed of 80% methoxy PLGA-PEG and 20% of PLGA-PEG-Maleimide. DiD-labeled nanoparticles (NPs) were added to the inner well of a trans-well system containing cultured LS174T or human PMP tissue. Diffusion of NPs was measured via fluorescence signal in the bottom well. In an ex vivo rat model, small intestine was treated with DiD-labeled NPs. In an in vivo murine LS174T subcutaneous tumor model, Nu/Nu nude mice received supratumoral injections (subcutaneous injection above the tumor) of DiD-labeled NPs. Thirty minutes after injection, mice were sacrificed, and tumors were collected. All tissue was cryosectioned, mounted with DAPI-containing media, and inspected via confocal microscopy.
Diffusion profiles of NPs through PMP and cultured LS174T cells were generated. PLGA-TPEG-NPs-20 diffused faster with ~ 100% penetration versus PLGA-PEG-NPs with ~ 40% penetration after 8 h. Increased diffusion of PLGA-TPEG-NPs-20 was further observed in ex vivo rat small intestine as evidenced by elevated luminal NP fluorescence signal on the luminal surface. Subcutaneous LS174T tumors treated with PLGA-TPEG-NPs-20 demonstrated greater diffusion of NPs, showing homogenous fluorescence signal throughout the tumor.
PLGA-TPEG-NPs-20 can be an effective mucin penetrating drug delivery system.
假性黏液瘤（PMP）的治疗失败部分归因于治疗药物无法有效穿透致密的黏液瘤屏障。我们通过低浓度的第二 PEG 层对聚（乳酸-共-乙醇酸）-b-聚乙二醇（PLGA-PEG-NPs）进行表面修饰（PLGA-TPEG-NPs-20），以降低其与蛋白质的结合亲和力并改善其在黏液中的扩散。
采用纳米沉淀法制备 PLGA-PEG-NPs。为构建 PLGA-TPEG-NPs-20 的第二 PEG 层，将 PEG-硫醇偶联到由 80%甲氧基 PLGA-PEG 和 20% PLGA-PEG-马来酰亚胺组成的 PLGA-PEG-NPs 上。将 DiD 标记的纳米颗粒（NPs）添加到含有培养的 LS174T 或人 PMP 组织的 Trans-well 系统的内孔中。通过底部孔中的荧光信号测量 NPs 的扩散。在离体大鼠模型中，用 DiD 标记的 NPs 处理小肠。在体内 LS174T 皮下肿瘤模型中，Nu/Nu 裸鼠接受 DiD 标记的 NPs 的肿瘤上皮下注射（肿瘤上方的皮下注射）。注射后 30 分钟，处死小鼠并收集肿瘤。所有组织均进行冷冻切片，用含 DAPI 的介质装片，然后通过共聚焦显微镜进行检查。
生成了 NPs 通过 PMP 和培养的 LS174T 细胞的扩散图谱。与 ~40%渗透的 PLGA-PEG-NPs 相比，PLGA-TPEG-NPs-20 在 8 小时后更快地扩散，具有 ~100%的穿透率。在离体大鼠小肠中观察到 PLGA-TPEG-NPs-20 扩散增加，这表现在腔表面上腔内 NP 荧光信号升高。用 PLGA-TPEG-NPs-20 处理的 LS174T 皮下肿瘤显示出 NP 的扩散更大，整个肿瘤呈现均匀的荧光信号。
PLGA-TPEG-NPs-20 可以作为一种有效的穿透黏液的药物传递系统。
