Ultrasound-triggered with ROS-responsive SN38 nanoparticle for enhanced combination cancer immunotherapy.

Controlled generation of cytotoxic reactive oxygen species (ROS) is essential in cancer therapy. Ultrasound (US)-triggered sonodynamic therapy (SDT) has shown considerable ability to trigger in situ ROS generation. Unfortunately, US therapy alone is insufficient to trigger an efficient anticancer response, owing to the induction of multiple immunosuppressive factors. It was identified that 7-ethyl-10-hydroxycamptothecin (SN38) could notably inhibit DNA topoisomerase I, induce DNA damage and boost robust anticancer immunity. However, limited by the low metabolic stability, poor bioavailability, and dose-limiting toxicity, the direct usage of SN38 is inadequate in immune motivation, which limits its clinical application. Hence, new strategies are needed to improve drug delivery efficiency to enhance DNA topoisomerase I inhibition and DNA damage and elicit a vigorous anticancer cancer immunity response. Considering US irradiation can efficiently generate large amounts of ROS under low-intensity irradiation, in this study, we aimed to design a polymeric, ROS-responsive SN38 nanoformulation for in vivo drug delivery. Upon the in-situ generation of ROS by US therapy, controlled on-demand release of SN38 occurred in tumor sites, which enhanced DNA damage, induced DC cell maturation, and boosted anticancer immunity. Our results demonstrated that a new strategy of involving the combination of a SN38 nanoformulation and US therapy could be used for cancer immunotherapy.

Comprehensive evaluation of biopolymer immune implants for peritoneal metastasis carcinoma therapy.

Immunotherapy has been widely used in the treatment of advanced stage cancers with spreading metastases, while the fully activation of immune system often requires sustained and long-acting immune stimulation by immunotherapeutic agents. In previous studies, we designed a biopolymer immune implant by dynamic covalent bonds and achieved sustained release of loaded immunotherapeutic agents, thus stimulated systemic immune activation and elicited immune memory effects. Herein, we further optimized the implants and carried out a comprehensive evaluation of the implants on peritoneal metastasis carcinoma (PMC) therapy. Our results showed that the implants fabricated with 8-arm polyethylene glycol amine (8-arm PEG-NH2) and 40% oxidation degree dextran (ODEX) exhibited a satisfactory degradation time for activating the antitumor immunity. The drug combination of oxaliplatin (OxP) and resiquimod (R848) could be sustainably released from the implants for 18 days. The implants cured 75% of mice with PMC and elicited immune memory effects to resist tumor re-challenge without obvious side effects observed. Mechanism analysis revealed that the implants could serve as an in-situ vaccine to enhance the infiltration of activated dendritic cells (DCs), T cells and natural killer (NK) cells inside the tumor, as well as increase the serum tumor necrosis factor α (TNF-α), interferon-γ (IFN-γ) and interleukin 12 (IL-12) levels. These results strongly support the clinical translation potential of this sustained released biopolymer immune implants for PMC therapy.

Cisplatin Nanoparticles Promote Intratumoral CD8+ T Cell Priming via Antigen Presentation and T Cell Receptor Crosstalk.

Nanomedicines are highly promising for cancer therapy due to their minimal side effects. However, little is known regarding their host immune response, which may limit their clinical efficacy and applications. Here, we find that cisplatin (CDDP)-loaded poly(l-glutamic acid)-graft-methoxy poly(ethylene glycol) complex nanoparticles (CDDP-NPs) elicit a strong antitumor CD8+ T cell-mediated immune response in a tumor-bearing mouse model compared to free CDDP. Mechanistically, the sustained retention of CDDP-NPs results in persistent tumor MHC-I overexpression, which promotes the formation of MHC-I-antigen peptide complex (pMHC-I), enhances the interaction between pMHC-I and T cell receptor (TCR), and leads to the activation of TCR signaling pathway and CD8+ T cell-mediated immune response. Furthermore, CDDP-NPs upregulate the costimulatory OX40 on intratumoral CD8+ T cells, and synergize with the agonistic OX40 antibody (aOX40) to suppress tumor growth by 89.2%. Our study provides a basis for the efficacy advantage of CDDP-based nanomedicines and immunotherapy.

A simple and general strategy for postsurgical personalized cancer vaccine therapy based on an injectable dynamic covalent hydrogel.

Cancer vaccines artificially stimulate the immune system against cancer and are considered the most promising treatment of cancer. However, the current progress in vaccine research against cancer is still limited and slow, partially due to the difficulties in identifying and obtaining tumor-specific antigens. Considering surgery as the first choice for tumor treatment in most cases, the authors evaluated whether the resected tumor can be directly used as a source of tumor antigens for designing personalized cancer vaccines. Based on this idea, herein, the authors report a dynamic covalent hydrogel-based vaccine (DCHVax) for personalized postsurgical management of tumors. The study uses proteins extracted from the resected tumor as antigens, CpG as the adjuvant, and a multi-armed poly(ethylene glycol) (8-arm PEG)/oxidized dextran (ODEX) dynamically cross-linked hydrogel as the matrix. Subcutaneous injection of DCHVax recruits dendritic cells to the matrix in situ and elicits robust tumor-specific immune responses. Thus, it effectively inhibits the postoperative growth of the residual tumor in several murine tumor models. This simple and personalized method to develop cancer vaccines may be promising in developing clinically relevant strategies for postoperative cancer treatment.

Manipulating Liver Bile Acid Signaling by Nanodelivery of Bile Acid Receptor Modulators for Liver Cancer Immunotherapy.

Gut bacteria and their metabolites influence the immune microenvironment of liver through the gut-liver axis, thus representing emerging therapeutic targets for liver cancer therapy. However, directly manipulating gut microbiota or their metabolites is not practical in clinic since the safety concerns and the complicated mechanism of action. Considering the dysregulated bile acid profiles associated with liver cancer, here we propose a strategy that directly manipulates the primary and secondary bile acid receptors through nanoapproach as an alternative and more precise way for liver cancer therapy. We show that nanodelivery of bile acid receptor modulators elicited robust antitumor immune responses and significantly changed the immune microenvironment in the murine hepatic tumor. In addition, ex vivo stimulation on both murine and patient hepatic tumor tissues suggests the observation here may be meaningful for clinical practice. This study elucidates a novel and precise strategy for liver cancer immunotherapy.

In-Situ-Sprayed Dual-Functional Immunotherapeutic Gel for Colorectal Cancer Postsurgical Treatment.

Surgery remains the most preferred treatment options for colorectal cancer (CRC). Paradoxically, local recurrence and distant metastasis are usually accelerated postsurgery as a consequence of local and systemic immunosuppression caused by surgery. Therefore, modulating tumor postoperative immune microenvironment and activating systemic antitumor immunity are necessary supplementaries for CRC therapy. Here, an in-situ-sprayed immunotherapeutic gel loaded with anti-OX40 antibody (iSGels@aOX40) is reported for CRC postsurgical treatment. The iSGel is formed instantly after spraying with strong adhesion ability via crosslinking between tannic acid (TA) and poly(l-glutamic acid)-g-methoxy poly(ethylene glycol)/phenyl boronic acid (PLG-g-mPEG/PBA). TA not only serves as one component of the iSGel but also relieves the postsurgical immunosuppressive microenvironment by inhibiting the activity of cyclo-oxygenase-2 (COX-2). The aOX40 serves as an immune agonistic antibody and is released from the iSGel in a constant manner lasting for over 20 days. In a subcutaneous murine CRC model, the iSGels@aOX40 results in complete inhibition on tumor recurrence. In addition, the cured mice show resistance to tumor re-challenge, suggesting that immune memory effects are established after the iSGels@aOX40 treatment. In an orthotopic CRC peritoneal metastatic model, the iSGels@aOX40 also remarkably inhibits the growth of the abdominal metastatic tumors, suggesting great potential for clinical CRC therapy.

Biopolymer Immune Implants' Sequential Activation of Innate and Adaptive Immunity for Colorectal Cancer Postoperative Immunotherapy.

Surgical resection is the first-line therapy for colorectal cancer (CRC). However, for advanced CRC, the curative effect of surgical resection is limited due to either local recurrence or distal metastasis. Postoperative in situ immunotherapy, presents a promising option for preventing tumor recurrence and metastasis, owing to the fact that surgeons have unique opportunities and direct access to the surgical site. Herein, a designed biopolymer immune implant for CRC post-surgical therapy, characterized with tissue adhesion, sustained drug release, and sequential elicitation of innate immunity, adaptive immunity, and immune memory effects, is reported. With gradual release of the loaded resiquimod (R848) and anti-OX40 antibody (aOX40), the immune implant can eradicate residual tumors post-surgery (with no tumor recurrence in 150 days), inhibit the growth of distal tumors and elicit immune memory effects to resist tumor re-challenge. Immunological analysis reveal that the biopolymer immune plant treatment leads to a two-stage action, with enhanced natural killer cells (NK cells) infiltration and activation of dendritic cells (DCs) in the first several days, then a greatly increased population of infiltrating T cells, and finally immune memory effects are established. The reported biopolymer immune implants provide a valuable and clinically-relevant option for post-surgical CRC management.

Precise delivery of obeticholic acid via nanoapproach for triggering natural killer T cell-mediated liver cancer immunotherapy.

Primary bile acids were reported to augment secretion of chemokine (C‒X‒C motif) ligand 16 (CXCL16) from liver sinusoidal endothelial cells (LSECs) and trigger natural killer T (NKT) cell-based immunotherapy for liver cancer. However, abundant expression of receptors for primary bile acids across the gastrointestinal tract overwhelms the possibility of using agonists against these receptors for liver cancer control. Taking advantage of the intrinsic property of LSECs in capturing circulating nanoparticles in the circulation, we proposed a strategy using nanoemulsion-loaded obeticholic acid (OCA), a clinically approved selective farnesoid X receptor (FXR) agonist, for precisely manipulating LSECs for triggering NKT cell-mediated liver cancer immunotherapy. The OCA-nanoemulsion (OCA-NE) was prepared via ultrasonic emulsification method, with a diameter of 184 nm and good stability. In vivo biodistribution studies confirmed that the injected OCA-NE mainly accumulated in the liver and especially in LSECs and Kupffer cells. As a result, OCA-NE treatment significantly suppressed hepatic tumor growth in a murine orthotopic H22 tumor model, which performed much better than oral medication of free OCA. Immunologic analysis revealed that the OCA-NE resulted in augmented secretion of CXCL16 and IFN-γ, as well as increased NKT cell populations inside the tumor. Overall, our research provides a new evidence for the antitumor effect of receptors for primary bile acids, and should inspire using nanotechnology for precisely manipulating LSECs for liver cancer therapy.

The impact of anastomotic leakage on oncology after curative anterior resection for rectal cancer: A systematic review and meta-analysis.

BACKGROUND: Anastomotic leakage (AL) is a serious clinical complication after anterior resection for rectal cancer and will lead to an increase in postoperative mortality. However, the effect on long-term oncology outcomes remains controversial. METHODS: We searched the PubMed, Embase, and Cochrane library databases for related articles. The included studies assessed local recurrence, distant recurrence, overall survival, cancer-specific survival and disease-free survival. The systematic reviews and meta-analyses was conducted in accordance with the PRISMA guidelines. The combined RRs with 95% CI were then calculated using a fixed effects model or a randomized effect model. RESULTS: A total of 18 cohort studies included 34,487 patients who met the inclusion criteria. The meta-analysis demonstrated that AL was associated with increased local recurrence (RR 1.47, 95% CI 1.14-1.90, I = 57.8%). Anastomotic leakage decreased overall survival (RR 0.92, 95% CI 0.88-0.96, I = 58.1%), cancer-specific survival (RR 0.96, 95% CI 0.92-1.00, I = 30.4%), and disease-free survival (RR 0.85, 95% CI 0.77-0.94, I = 80.4%). Distant recurrence may had no significant effects of AL (RR 1.16, 95% CI 0.91-1.46, I = 58.4%). CONCLUSION: AL has a negative effect on local recurrence and long-term survival (including overall survival, cancer-specific survival, and disease-free survival) after anterior resection for rectal cancer, but not related to distant recurrence.

Biodegradable Implants Combined with Immunogenic Chemotherapy and Immune Checkpoint Therapy for Peritoneal Metastatic Carcinoma Postoperative Treatment.

Peritoneal seeding represents one of the most frequent sites of metastasis for late-stage gastrointestinal and gynecological cancer. At present, the major treatment method for peritoneal metastatic carcinoma (PMC) is the combination of cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC). Nevertheless, the 5 year survival rate of patients after these treatments is still far from satisfactory. Here, we report a biodegradable implant co-loaded with doxorubicin (DOX) and anti-PD-1 monoclonal antibody (aPD-1) (BI@DOX+aPD-1) for a combination of immunogenic chemotherapy and immune checkpoint therapy for PMC postoperative treatment. The bio-implant is fabricated with oxidized dextran (ODEX) and 4-arm poly(ethylene glycol) amine (4-arm PEG-NH2) by Schiff's base reaction at mild conditions, with DOX and aPD-1 loaded inside during and after the fabrication process, respectively. In vitro studies confirmed the slow and sustained release of DOX and aPD-1 from the bio-implants. In vivo studies showed that the bio-implants could be gradually degraded and maintain relatively high concentrations of therapeutic agents in the mouse abdomen. In a murine CT26 PMC model, the BI@DOX+aPD-1 resulted in a 89.7% tumor-suppression rate after peritoneal implantation. Importantly, the combination therapy of DOX and aPD-1 in the bio-implant showed an excellent synergistic effect with a Q value of 2.35. This easy-fabricated bio-implant combined with DOX and aPD-1 should be promising for clinical PMC postoperative treatment.

[Comparative study of three-dimensional and two-dimensional laparoscopic-assisted D2 radical gastrectomy in short-term efficacy].

OBJECTIVE: To evaluate the advantage and short-term efficacy of three-dimensional (3D) laparoscopic-assisted D2 radical gastrectomy for gastric cancer. METHODS: Clinical data of 116 gastric cancer patients who underwent laparoscopic-assisted D2 radical gastrectomy in our department from January 2014 to August 2015 were analyzed retrospectively. Among 116 patients, 56 received 3D and 60 received two-dimensional(2D) technique respectively. All the surgeries were performed by the same team. The operative parameters, short-term efficacy and hospital expense were compared between the two groups. RESULTS: There were no significant differences between the two groups in baseline data(all P>0.05). All the operations were performed successfully without conversion. Compared with 2D group, 3D group had shorter operative time [(186.2±22.8) minutes vs. (198.1±26.4) minutes, t=2.589, P=0.011], less intraoperative blood loss [(73.6±28.5) ml vs. (88.1±32.3)ml, t=2.555, P=0.012]. Whereas no significant differences in dissected lymph nodes(36.5±6.6 vs. 34.5±5.4, P=0.073), time to first flatus[(3.1±1.5) days vs. (3.3±1.8) days, P=0.729], length of hospital stay[(11.7±2.9) days vs. (12.6±3.1) days, P=0.088], incidence of postoperative complications [8.9%(5/56) vs. 11.7%(7/60), P=0.628] and hospitalization cost [(8.6±1.4)×10(4) yuan vs. (8.1±1.2)×10(4) yuan, P=0.055] were found between two groups. CONCLUSION: Three-dimensional laparoscopic-assisted D2 radical gastrectomy may be advantageous over two-dimensional laparoscopic-assisted D2 radical gastrectomy.