Redox-Activated Porphyrin-Based Liposome Remote-Loaded with Indoleamine 2,3-Dioxygenase (IDO) Inhibitor for Synergistic Photoimmunotherapy through Induction of Immunogenic Cell Death and Blockage of IDO Pathway.

Immunotherapy through stimulating the host immune system has emerged as a powerful therapeutic strategy for various malignant and metastatic tumors in the clinic. However, harnessing the immune system for cancer treatment often fails to obtain a durable response rate due to the poor immunogenicity and the strong immunosuppressive milieu in the tumor site. Herein, a redox-activated liposome was developed from the self-assembly of the porphyrin-phospholipid conjugate and coencapsulation of indoleamine 2,3-dioxygenase (IDO) inhibitor into the interior lumen via remote-loading for simultaneous induction of immunogenic cell death (ICD) and reversing of suppressive tumor microenvironment. The nanoparticle exhibited prolonged blood circulation and enhanced tumor accumulation in the 4T1 tumor-bearing mice after intravenous injection. The nanovesicle could render exponential activation of fluorescence signal and photodynamic therapy (PDT) activity (>100-fold) in response to the high level of intracellular glutathione after endocytosed by tumor cells, thereby achieving effective inhibition of tumor growth and reduced phototoxicity to normal tissues owing to the activatable design of the nanoparticle. More importantly, redox-activated PDT induced intratumoral infiltration of cytotoxic T lymphocytes by induction of ICD of tumor cells. After combining with the IDO inhibitor, the systemic antitumor immune response was further augmented. Hence, we believe that the present nanovesicle strategy has the potential for the synergistic immunotherapy of the metastatic cancers.

A tenascin C targeted nanoliposome with navitoclax for specifically eradicating of cancer-associated fibroblasts.

Cancer-associated fibroblasts (CAFs) play a vitally important role during tumor progression. Navitoclax (Nav) can specifically induce apoptosis in CAFs. The present study aims to develop a novel CAF-targeted nanoliposome for cancer therapy. Nav-loaded nanoliposomes modified with peptide FH (FH-SSL-Nav), which specifically binds to tenascin C, a protein mainly expressed by CAFs, were formulated and characterized. Several experiments were performed to evaluate CAFs selective apoptosis, targeting and eradicating. Compared with SSL-Nav, FH-SSL-Nav achieved higher cellular uptake, and exhibited stronger cytotoxicity in vitro. The in vivo tumor stroma targeting effect was further confirmed by near infrared imaging. Accordingly, FH-SSL-Nav displayed improved tumor growth inhibition by eradicating CAFs in Hep G2 tumor-bearing nude mice model. In conclusion, FH-SSL-Nav could achieve targeting delivery of Nav to CAFs in vitro and in vivo, and may offer a potential strategy for cancer therapy based on tumor stroma. From the Clinical Editor: The progression of cancer cells often depends on the underlying tumor microenvironment, in which cancer-associated fibroblasts play an important role. In this article, the authors developed targeted therapy against CAFs using liposomes as carriers. This new modality was shown to be more effective in tumor killing both in vitro and in vivo. The finding may open a new era in cancer therapy.

Ruminal degradation characteristics of bagasse with different fermentation treatments in the rumen of beef cattle.

This experiment aimed to study the degradation characteristics of bagasse after three fermentation treatments in beef cattle. Bagasse 1 was treated with 0.3% lactic acid bacteria (w/w). Bagasse 2 was treated with 0.3% mixed strains (Saccharomyces cerevisiae, Aspergillus niger, Aspergillus oryzae, and lactic acid bacteria at 2:1:1:1). Bagasse 3 was treated with 0.1% cellulase and 0.1% xylanase in addition to 0.3% mixed strains of bagasse 2. The dry matter (DM), crude ash (ASH), crude protein (CP), neutral detergent fiber (NDF), and acid detergent fiber (ADF) in the bagasses were determined. Compared to the control bagasse (without the strain and enzyme treatments), three fermented bagasses showed higher DM after 4 h fermentation. The CP and ASH contents in fermented bagasse 3 were the highest, while the contents of NDF and ADF in fermented bagasse 3 were the lowest among all the groups. The effective degradability of DM, CP, NDF, and ADF was highest in fermented bagasse 3 among the evaluated bagasse feed, followed by fermented bagasse 2 > fermented bagasse 1 > bagasse. Overall, fermented bagasse 3 was better than the control and other treated bagasses, thus fermented bagasse 3 is a hopeful source for ruminant diet of beef cattle.

Rethinking nanoparticulate polymer-drug conjugates for cancer theranostics.

Polymer-drug conjugates (PDCs) fabricated as nanoparticles have hogged the limelight in cancer theranostics in the past decade. Many researchers have devoted to developing novel and efficient polymeric drug delivery system since the first generation of poly(N-[2-hydroxypropyl]methacrylamide) copolymer-drug conjugates. However, none of them has been approved for chemotherapy in clinic. An ideal PDC nanoparticle for cancer theranostics should possess several properties, including prolonged circulation in blood, sufficient accumulation and internalization in tumors, and efficient drug release in target sites. To achieve these goals, it is important to rationally design the nanoparticulate PDCs based on circulation, accumulation, penetration, internalization, and drug release (CAPIR) cascade. Specifically, CAPIR cascades are divided into five steps: (1) circulation in the vascular compartment without burst release, (2) accumulation in tumors via enhanced permeability and retention effect, (3) subsequent penetration into the deep regions of tumors, (4) internalization into tumor cells, and (5) release of drugs as free molecules to exert their pharmacological effects. In this review, we focus on the development and novel approaches of nanoparticulate PDCs based on CAPIR cascade, and provide an outlook on future clinical application. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease.

α-Conotoxin ImI-modified polymeric micelles as potential nanocarriers for targeted docetaxel delivery to α7-nAChR overexpressed non-small cell lung cancer.

A micelle system modified with α-Conotoxin ImI (ImI), a potently antagonist for alpha7 nicotinic acetylcholine receptor (α7-nAChR) previously utilized for targeting breast cancer, was constructed. Its targeting efficiency and cytotoxicity against non-small cell lung cancer (NSCLC) highly expressing α7-nAChR was investigated. A549, a non-small cell lung cancer cell line, was selected as the cell model. The cellular uptake study showed that the optimal modification ratio of ImI on micelle surface was 5% and ImI-modification increased intracellular delivery efficiency to A549 cells via receptor-mediated endocytosis. Intracellular Ca2+ transient assay demonstrated that ImI modification led to enhanced molecular interaction between nanocarriers and A549 cells. The in vivo near-infrared fluorescence imaging further revealed that ImI-modified micelles could facilitate the drug accumulation in tumor sites compared with non-modified micelles via α7-nAChR mediation. Moreover, docetaxel (DTX) was loaded in ImI-modified nanomedicines to evaluate its in vitro cytotoxicity. As a result, DTX-loaded ImI-PMs exhibited greater anti-proliferation effect on A549 cells compared with non-modified micelles. Generally, our study proved that ImI-modified micelles had targeting ability to NSCLC in addition to breast cancer and it may provide a promising strategy to deliver drugs to NSCLC overexpressing α7-nAChR.

Localized co-delivery of collagenase and trastuzumab by thermosensitive hydrogels for enhanced antitumor efficacy in human breast xenograft.

Modulation of the collagen-rich extracellular matrix (ECM) in solid tumors by the treatment with collagenase has been proved effective in enhancement of the interstitial transport and antitumor efficacy of antibodies. We, therefore, developed a PLGA-PEG-PLGA polymer-based thermosensitive hydrogel, which incorporated a HER2-targeted monoclonal antibody trastuzumab and collagenase (Col/Tra/Gel) for peritumoral administration. HER2-positvie BT474 tumor-bearing mice were selected as a model. The Col/Tra/Gel showed the continuous and biphasic release of protein drugs for 9 days in vitro. NIR imaging studies demonstrated a long-term retention of Col/Tra/Gel hydrogel in the peritumoral area for over 20 days. Treatment with Col/Tra/Gel reduced the collagen density and enhanced apoptotic cell death in tumor tissue, resulting in superior treatments with increased efficacy and reduced toxicity compared with other control groups. Moreover, a quarter-dose of Col/Tra/Gel exhibited a better antitumor efficacy than that of intravenous injection of clinical trastuzumab formulation. This localized co-delivery system offers a potential strategy for the modulation of dense ECM and enhancement of antibody efficacy.

Comprehensively priming the tumor microenvironment by cancer-associated fibroblast-targeted liposomes for combined therapy with cancer cell-targeted chemotherapeutic drug delivery system.

Cancer-associated fibroblasts (CAFs) not only support tumorigenesis and tumor metastasis by reciprocal cellular cross-talk with cancer cells, but also remodel the extracellular matrix (ECM) and architecture of tumor microenvironment. This leads to poor tumor penetration of traditional chemotherapeutic nanomedicines and resulting drug resistance. In this study, we use a novel tumor stroma-targeted nanovehicle (FH-SSL-Nav) to specifically eradicate CAFs, promote tumor penetration of nanomedicines and cut off the stroma's support to cancer cells. FH-SSL-Nav exhibited excellent and comprehensive tumor microenvironment modulation including downregulation ECM deposition, decreasing interstitial fluid pressure (IFP) and facilitating blood perfusion. As a result, more chemotherapeutic drug delivery systems penetrated deep into tumor spheroids in vitro and tumor tissues in vivo. Furthermore, chemotherapeutic drug resistance induced by microenvironment was partly reversed by FH-SSL-Nav. In a human Hep G2 xenograft nude mouse model, FH-SSL-Nav greatly improved the tumor suppression of cancer cell-targeted liposomal doxorubicin (7pep-SSL-DOX) with low dose and low toxicity. Since Nav and DOX exhibited no synergy against Hep G2 cells, it was clear that the improved antitumor efficacy was basically due to the comprehensive tumor microenvironment priming by FH-SSL-Nav.