A tumor cell membrane-coated self-amplified nanosystem as a nanovaccine to boost the therapeutic effect of anti-PD-L1 antibody

To improve the response rate of immune checkpoint inhibitors such as anti-PD-L1 antibody in immunosup-pressive cancers like triple-negative breast cancer(TNBC),induction of immunogenic cell death(ICD)at tumor sites can increase the antigenicity and adjuvanticity to activate the immune microenvironment so that tumors become sensitive to the intervention of immune checkpoint inhibitors.Herein,a self-amplified biomimetic nanosystem,mEHGZ,was constructed by encapsulation of epirubicin(EPI),glucose oxidase(Gox)and hemin in ZIF-8 nanoparticles and coating of the nanoparticles with calreticulin(CRT)over-expressed tumor cell mem-brane.EPI acts as an ICD inducer,Gox and hemin medicate the cascade generation of reactive oxygen species(ROS)to strengthen the ICD effect,and CRT-rich membrane as“eat me”signal promote presentation of the released antigens by dendritic cells(DCs)to invoke the tumor-immunity cycle.The biomimetic delivery system displays an amplified ICD effect via Gox oxidation,hydroxyl radical generation and glutathione(GSH)depletion.The induced potent ICD effect promotes DCs maturation and cytotoxic T lymphocytes(CTLs)infiltration,reversing an immunosuppressive tumor microenvironment to an immunoresponsive one.Treatment with the nanosystem in combination with anti-PD-L1 antibody results in distinctive inhibition of tumor growth and lung metastasis,supporting that a potent ICD effect can significantly boost the therapeutic efficacy of the anti-PD-L1 antibody.This self-amplified biomimetic nanoplatform offers a promising means of raising the response rate of immune checkpoint inhibitors.

Corrigendum to “A tumor cell membrane-coated self-amplified nanosystem as a nanovaccine to boost the therapeutic effect of anti-PD-L1 antibody” [Bioact. Mater. 21 299-312]

The authors regret the incorrect publication of corresponding authors for the article.The corresponding authors have been updated as Hongyan Zhu(hyzhu_hmrrc@126.com)and Kui Luo(luokui@scu.edu.cn),and the same should be updated in the supplementary file as well.

Branched glycopolymer prodrug-derived nanoassembly combined with a STING agonist activates an immuno-supportive status to boost anti-PD-L1 antibody therapy

Despite the great potential of anti-PD-L1 antibodies for immunotherapy,their low response rate due to an immunosuppressive tumor microenvironment has hampered their application.To address this issue,we constructed a cell membrane-coated nanosystem(mB4S)to reverse an immunosuppressive microenvironment to an immuno-supportive one for strengthening the anti-tumor effect.In this system,Epirubicin(EPI)as an immunogenic cell death(ICD)inducer was coupled to a branched glycopolymer via hydrazone bonds and diABZI as a stimulator of interferon genes(STING)agonist was encapsulated into mB4S.After internalization of mB4S,EPI was acidic-responsively released to induce ICD,which was characterized by an increased level of calreticulin(CRT)exposure and enhanced ATP secretion.Meanwhile,diABZI effectively activated the STING pathway.Treatment with mB4S in combination with an anti-PD-L1 antibody elicited potent immune responses by increasing the ratio of matured dendritic cells(DCs)and CD8+T cells,promoting cytokines secretion,up-regulating M1-like tumor-associated macrophages(TAMs)and down-regulating immunosuppressive myeloid-derived suppressor cells(MDSCs).Therefore,this nanosystem for co-delivery of an ICD inducer and a STING agonist achieved promotion of DCs maturation and CD8+T cells infiltration,creating an immuno-supportive microenvironment,thus potentiating the therapy effect of the anti-PD-L1 antibody in both 4T1 breast and CT26 colon tumor mice.

Cathepsin B-responsive and gadolinium-labeled branched glycopolymer-PTX conjugate-derived nanotheranostics for cancer treatment

Multi-modal therapeutics are emerging for simultaneous diagnosis and treatment of cancer.Polymeric carriers are often employed for loading multiple drugs due to their versatility and controlled release of these drugs in response to a tumor specific microenvironment.A theranostic nanomedicine was designed and prepared by complexing a small gadolinium chelate,conjugating a chemotherapeutic drug PTX through a cathepsin B-responsive linker and covalently bonding a fluorescent probe pheophorbide a(Ppa)with a branched glycopolymer.The branched prodrug-based nanosystem was degradable in the tumor microenvironment with overexpressed cathepsin B,and PTX was simultaneously released to exert its therapeutic effect.The theranostic nanomedicine,branched glycopolymer-PTX-DOTA-Gd,had an extended circulation time,enhanced accumulation in tumors,and excellent biocompatibility with significantly reduced gadolinium ion(Gd3+)retention after 96 h post-injection.Enhanced imaging contrast up to 24 h post-injection and excellent antitumor efficacy with a tumor inhibition rate more than 90%were achieved from glycopolymer-PTX-DOTA-Gd without obvious systematic toxicity.This branched polymeric prodrug-based nanomedicine is very promising for safe and effective diagnosis and treatment of cancer.

Dendron-polymer hybrid mediated anticancer drug delivery for suppression of mammary cancer

Dendron-polymer-based nanoscale and stimuli-responsive drug delivery systems have shown great promise in tumor-targeting accumulation without significant toxicity.Here we report a dendronized polymer-doxorubicin(DOX)hybrid(DPDH)with an improved in vivo drug delivery efficiency for cancer therapy compared with a linear polymer-DOX conjugate(LPDC).The in vitro drug release profile of DOX indicates that DPDH displays pH-responsive drug release due to cleavage of hydrazone bonds since a greater amount of DOX is released at pH 5.2 at a faster rate than at pH 7.4.DPDH efficiently enters 4 T1 cells and releases DOX to induce cytotoxicity and apoptosis.Owing to the dendronzied structure,DPDH has a significantly longer blood circulation time than LPDC.DPDH substantially enhances the therapeutic efficacy to suppress tumor growth in a 4 T1 mammary cancer model than LPDC as well as free drug,evidenced from tumor growth inhibition,TUNEL assessment and histological analysis.Biosafety of DPDH is also confirmed from hemolysis,body weight shifts during treatment and pathological analysis.This study demonstrates the use of dendronized polymer-DOX hybrids for specific drug molecules is a promising approach for drug delivery.

Two dehydroecdysone reductases act as fat body-specific 20E catalyzers in Bombyx mori

Periodic post-embryonic changes in insects, including growth, development and metamorphosis, are strictly controlled by many compounds, including steroid hormones. The biosynthesis and clearance of 20-hydroxyecdysone (20E), the major active form of the insect steroid hormone ecdysone, result in titer fluctuations that help control insect development. The inactivation of 20E in the silkworm Bombyx mori is highly tissue-specific, with CYP18A1 and ecdysone oxidase controlling 20E inactivation specifically in the mid-silk gland and midgut, respectively. Here, we characterized silkworm 3-dehydroecdysone 3α reductase (Bm3DE3α) and 3-dehydroecdysone 3β reductase (Bm3DE3β), two enzymes involved predominantly in the C-3-mediated catalysis of 20E in fat bodies. The ubiquitous and silk gland-specific overexpression of Bm3DE3α decreased the 20E titer, resulting in larval lethality and larval–pupal transition failure, respectively. In contrast, the ubiquitous and mid-silk gland-specific overexpression of Bm3DE3β increased the 20E titer, resulting in larval growth delays and lethality at the mid-fifth larval stage, respectively. Thus, Bm3DE3α and Bm3DE3β mediate fat body-specific steroid hormone metabolism in B. mori, indicating that highly diversified 20E metabolism-related mechanisms exist in different insect species.