Microrobots that can be precisely guided to target lesions have been studied for in vivo medical applications. However, existing microrobots have challenges in vivo such as biocompatibility, biodegradability, actuation module, and intra- and postoperative imaging. This study reports microrobots visualized with real-time x-ray and magnetic resonance imaging (MRI) that can be magnetically guided to tumor feeding vessels for transcatheter liver chemoembolization in vivo. The microrobots, composed of a hydrogel-enveloped porous structure and magnetic nanoparticles, enable targeted delivery of therapeutic and imaging agents via magnetic guidance from the actuation module under real-time x-ray imaging. In addition, the microrobots can be tracked using MRI as postoperative imaging and then slowly degrade over time. The in vivo validation of microrobot system–mediated chemoembolization was demonstrated in a rat liver with a tumor model. The proposed microrobot provides an advanced medical robotic platform that can overcome the limitations of existing microrobots and current liver chemoembolization.

Background and Aims: The effectiveness of gemcitabine-based adjuvant chemotherapy is unclear in cholangiocarcinoma. We investigated the role of adjuvant gemcitabine plus cisplatin (GemCis) in a homogeneous group of high-risk patients with resected, lymph node–positive extrahepatic cholangiocarcinoma. Approach and Results: Adenocarcinoma of perihilar or distal bile duct with regional lymph node metastasis who underwent curative-intent surgery (R0/R1) was eligible. Patients were randomized to receive GemCis (gemcitabine 1000 mg/m², cisplatin 25 mg/m² on days 1 and 8) or capecitabine (1250 mg/m² twice daily on days 1–14) every 3 weeks for 8 cycles. Primary endpoint was disease-free survival. Secondary endpoints were overall survival and safety. All p values are 1 sided and were considered significant if <0.1. Between July 2017 and November 2020, 101 patients (50 in the GemCis and 51 in the capecitabine group) were included in the intention-to-treat population. Perihilar and distal bile ducts were the primary sites in 45 (44.6%) and 56 (55.4%) patients, respectively, and 32 (31.7%) had R1 resections. Median (1-sided 90% CI) follow-up duration was 33.4 (30.5–35.8) months. In the GemCis and capecitabine group, 2-year disease-free survival rates were 38.5% (29.5%–47.4%) and 25.1% (17.4%–33.5%) [HR=0.96 (CI, 0.71–1.30), p=0.430], and median overall survival was 35.7 months (29.5–not estimated) and 35.7 months (30.9–not estimated) [HR=1.08 (CI, 0.71–1.64), 1-sided p=0.404], respectively. Grade 3–4 adverse events occurred in 42 (84.0%) and 8 patients (16.0%) in the GemCis and capecitabine groups, respectively. No treatment-related deaths were reported. Conclusions: In resected lymph node–positive extrahepatic cholangiocarcinoma, adjuvant GemCis did not improve survival outcomes compared with capecitabine.

Pancreatic cancer is characterized by late detection, frequent drug resistance, and a highly metastatic nature, leading to poor prognosis. Antibody-based immunotherapy showed limited success for pancreatic cancer, partly owing to the low delivery rate of the drug into the tumor. Herein, we describe a poly(lactic-co-glycolic acid;PLGA)-based siRNA nanoparticle targeting PD-L1 (siPD-L1@PLGA). The siPD-L1@PLGA exhibited efficient knockdown of PD-L1 in cancer cells, without affecting the cell viability up to 6 mg/mL. Further, 99.2% of PDAC cells uptake the nanoparticle and successfully blocked the IFN-gamma-mediated PD-L1 induction. Consistently, the siPD-L1@PLGA sensitized cancer cells to antigen-specific immune cells, as exemplified by Ovalbumin-targeting T cells. To evaluate its efficacy in vivo, we adopted a pancreatic PDX model in humanized mice, generated by grafting CD34⁺ hematopoeitic stem cells onto NSG mice. The siPD-L1@PLGA significantly suppressed pancreatic tumor growth in this model with upregulated IFN-gamma positive CD8 T cells, leading to more apoptotic tumor cells. Multiplex immunofluorescence analysis exhibited comparable immune cell compositions in control and siPD-L1@PLGA-treated tumors. However, we found higher Granzyme B expression in the siPD-L1@PLGA-treated tumors, suggesting higher activity of NK or cytotoxic T cells. Based on these results, we propose the application of siPD-L1@PLGA as an immunotherapeutic agent for pancreatic cancer.

Efficacy and safety of neoadjuvant FOLFIRINOX for borderline resectable pancreatic adenocarcinoma: improved efficacy compared with gemcitabine-based regimen Efficacy and Safety of Neoadjuvant FOLFIRINOX for Borderline Resectable Pancreatic Adenocarcinoma: Improved Efficacy Compared with Gemcitabine-based Regimen