Novel Cocktail Therapy Based on a Nanocarrier with an Efficient Transcytosis Property Reverses the Dynamically Deteriorating Tumor Microenvironment for Enhanced Immunotherapy.

The immune checkpoint blockade (ICB) faces a low response rate in clinical cancer treatment. Chemotherapy could enhance the response rate of the ICB, but patients would suffer from side effects. The off-target toxicity could be reduced by loading the chemotherapeutic agent through nanocarriers. Therefore, we developed a polymeric carrier for doxorubicin (DOX) loading to form DOX nanoparticles (DOX NPs), which were spatiotemporally responsive to the tumor microenvironment (TME). DOX NPs had an efficient transcytosis property for deep tumor infiltration and sustained drug release ability. Unfortunately, a binary therapy of DOX NPs and ICB induces tumor adaptive resistance and causes dynamic deterioration of the TME. We propose for the first time that TGF-ß1 is a major cause of tumor adaptive resistance and developed an immune cocktail therapy containing DOX NPs, ICB, and TGF-ß1 gene silencing nanoparticles. This therapy successfully overcame tumor adaptive resistance by reversing the immunosuppressive TME and achieved enhanced tumor treatment efficiency.

Photothermal-Chemotherapy Enhancing Tumor Immunotherapy by Multifunctional Metal-Organic Framework Based Drug Delivery System.

Immunotherapy holds great promise for patients undergoing tumor treatment. However, the clinical effect of immunotherapy is limited because of tumor immunogenicity and its immunosuppressive microenvironment. Herein, the metal-organic framework (MIL-100) loaded with chemotherapeutic agent mitoxantrone (MTO) was combined with photothermal-chemotherapy for enhancing immunogenic cell death. MIL-100 loaded with MTO and hyaluronic acid as nanoparticles (MMH NPs) yielded an NP with two therapeutic properties (photothermal and chemotherapy) with dual imaging modes (photoacoustic and thermal). When MMH NPs were coinjected with an anti-OX40 antibody in colorectal cancer, the highest antitumor efficacy and a robust immune effect were achieved. This work provides a novel combined therapeutic strategy, which will hold great promise in future tumor therapy.

Tumor microenvironment as the "regulator" and "target" for gene therapy.

In this review, we focus on strategies for designing functional nano gene carriers, as well as choosing therapeutic genes targeting the tumor microenvironment. Gene mutations have a great impact on the occurrence of cancer. Thus, gene therapy plays a major role in cancer therapy and has the potential to cure cancer. Well-designed gene therapy largely relies on effective gene carriers, which can be divided into viral carriers and non-viral carriers. A gene carrier delivers functional genes to their intracellular target and avoids nucleic acids being degraded by nucleases in the serum. Most conventional cancer gene therapies only target cancer cells and do not appear to be sufficintly efficient to pass clinical trials. Accumulating evidence has shown that extending the therapeutic strategies to the tumor microenvironment, rather than the tumor cell itself, can allow more options for achieving robust anti-cancer efficiency. In addition, unusual features between tumor microenvironment and normal tissues, such as a lower pH, higher glutathione and reactive oxygen species concentrations, and overexpression of some enzymes, facilitate the design of smart stimuli-responsive gene carriers regulated by the tumor microenvironment. These carriers interact with nucleic acids and then form stable nanoparticles under physiological conditions. By regulation of the tumor microenvironment, stimuli-responsive gene carriers are able to change their properties and achieve high gene delivery efficiency. Considering the tumor microenvironment as the "regulator" and "target" when designing gene carriers and choosing therapeutic genes shows significant benefit with respect to improving the accuracy and efficiency of cancer gene therapy.

A Comprehensive Strategy Based on High Clinical Translational Nanosystem for Programmable Immunotherapy of Triple Negative Breast Cancer.

Triple negative breast cancer (TNBCs), known as an immunologically cold tumor, is difficult to completely eliminate with existing monotherapies, let alone metastasis and recurrence. It is urgent to design a rational combination of multiple therapies to programmatically reconstitute tumor microenvironment (TME) and reverse the immune "cold" into "hot" inflammatory tumors to improve the therapeutic effect. Hence, in this work, a multifunctional nanosystem (FeSH NPs) that integrates metal-polyphenol coordination complex as a photothermal agent and polyphenol, salvianolic acid B (SAB) as immunomodulator is designed and fabricated for synergistic photothermal-immunotherapy of TNBCs combined with anti-PD-L1 antibody. Guided by photothermal/photoacoustic dual-mode imaging, photothermal therapy (PTT) caused by FeSH NPs induces immunogenic cell death (ICD) under 808 nm laser irradiation. Subsequently, the loaded SAB is released with the addition of deferoxamine mesylate (DFO) to remodel TME, specifically TGF-ß inhibition and PD-L1 upregulation, and eliminate the primary tumors. The combination of PTT and TME reprogramming by FeSH NPs further synergizes with anti-PD-L1 antibody to eradicate recurrence and inhibit metastasis of TNBCs concurrently. Given the biosafety of FeSH NPs throughout the lifecycle, this work provides a protocol with high clinical translational promise for comprehensive programmed therapeutics of immunologically cold tumors TNBCs.

A Versatile Nanovaccine Enhancement Strategy Based on Suction-Inspired Physical Therapy.

Vaccine technology is effective in preventing and treating diseases, including cancers and viruses. The efficiency of vaccines can be improved by increasing the dosage and frequency of injections, but it would bring an extra burden to people. Therefore, it is necessary to develop vaccine-boosting techniques with negligible side effects. Herein, we reported a cupping-inspired noninvasive suction therapy that could enhance the efficacy of cancer/SARS-CoV-2 nanovaccines. Negative pressure caused mechanical immunogenic cell death and released endogenous adjuvants. This created a subcutaneous niche that would recruit and activate antigen-presenting cells. Based on this universal central mechanism, suction therapy was successfully applied in a variety of nanovaccine models, which include prophylactic/therapeutic tumor nanovaccine, photothermal therapy induced in situ tumor nanovaccine, and SARS-CoV-2 nanovaccine. As a well-established physical therapy method, suction therapy may usher in an era of noninvasive and high-safety auxiliary strategies when combined with vaccines.

A Multifunctional Nanoparticle Mitigating Cytokine Storm by Scavenging Multiple Inflammatory Mediators of Sepsis.

Sepsis is a disease caused by infection, which is characterized by a dysregulated immune response in the host and affects more than 30 million people worldwide each year. However, the current single therapeutic approaches are not effective in controlling the progression of sepsis. Here, we synthesize a nanoparticle (TMP) containing tannic acid (TA), Polymyxin B (PMB), and Mn2+ (Mn) by a simple one-pot method. TMP has the following characteristics: (1) All components have good biocompatibility; (2) simple preparation process without subsequent processing; (3) antibacterial and remove multiple inflammatory mediators; and (4) effectively mitigating cytokine storm both in the acute lung injury (ALI) and the cecal ligation and puncture (CLP) model. Our results demonstrate the critical role of targeting multiple mediators to mitigate cytokine storms for the treatment of sepsis.

CD47KO/CRT dual-bioengineered cell membrane-coated nanovaccine combined with anti-PD-L1 antibody for boosting tumor immunotherapy.

Tumor vaccines trigger tumor-specific immune responses to prevent or treat tumors by activating the hosts' immune systems, and therefore, these vaccines have potential clinical applications. However, the low immunogenicity of the tumor antigen itself and the low efficiency of the vaccine delivery system hinder the efficacy of tumor vaccines that cannot produce high-efficiency and long-lasting antitumor immune effects. Here, we constructed a nanovaccine by integrating CD47KO/CRT dual-bioengineered B16F10 cancer cell membranes and the unmethylated cytosine-phosphate-guanine (CpG) adjuvant. Hyperbranched PEI25k was used to load unmethylated cytosine-phosphate-guanine (CpG) through electrostatic adsorption to prepare PEI25k/CpG nanoparticles (PEI25k/CpG-NPs). CD47KO/CRT dual-bioengineered cells were obtained by CRISPR-Cas9 gene editing technology, followed by the cell surface translocation of calreticulin (CRT) to induce immunogenic cell death (ICD) in vitro. Finally, the extracted cell membranes were coextruded with PEI25k/CpG-NPs to construct the CD47KO/CRT dual-bioengineered cancer cell membrane-coated nanoparticles (DBE@CCNPs). DBE@CCNPs could promote endocytosis of antigens and adjuvants in murine bone marrow derived dendritic cells (BMDCs) and induce their maturation and antigen cross-presentation. To avoid immune checkpoint molecule-induced T cell dysfunction, the immune checkpoint inhibitor, the anti-PD-L1 antibody, was introduced to boost tumor immunotherapy through a combination with the DBE@CCNPs nanovaccine. This combination therapy strategy can significantly alleviate tumor growth and may open up a potential strategy for clinical tumor immunotherapy.

Metformin reprograms tumor microenvironment and boosts chemoimmunotherapy in colorectal cancer.

Tumor stroma plays an important role in the occurrence, development, and metastasis of colorectal cancer (CRC). The dense collagenous stroma forms a physical barrier for antitumor drugs and sustains a highly tumor immunosuppressive microenvironment. To address this issue, a spatiotemporal combination of antitumor stroma and nanoscale functional materials was used as an antitumor strategy for reprogramming the tumor immune microenvironment. In this combination, metformin hydrochloride (MET) was intraperitoneally injected to disrupt the dense tumor stroma for promoting drug delivery and remodeling the tumor immune microenvironment. Subsequently, intravenously injected multifunctional drug-delivery materials (MIL-100/mitoxantrone/hyaluronic acid nanoparticles, MMH NPs) were visualized by double imaging (photoacoustic (PA) and fluorescence imaging) and generated a robust immune response via immunogenic cell death (ICD). More importantly, the combination treatment also acted synergistically with the anti-OX40 agonist antibody (αOX40), which enhanced the treatment of orthotopic CRC. In summary, the combination strategy of MET/MMH NPs/αOX40 provides a novel and effective clinical option for CRC therapy.

Cationic polymer synergizing with a disulfide-containing enhancer achieved efficient nucleic acid and protein delivery.

To improve the efficiency of nucleic acid and protein delivery by cationic polymers, there is a trade-off between increasing the positive charge density of cationic polymers and decreasing cytotoxicity. In this work, a strategy to introduce multiple interactions between the cell membrane and a delivery system based on cationic polymers was proposed. A novel delivery system consisting of PEI1.8k and an enhancer (LA-RT) was fabricated. The introduction of LA-RT contributed to multiple interactions between the delivery system and the cell membrane including electrostatic interactions, hydrogen bonding, hydrophobic interaction, and dynamic sulfur exchange reactions, which enabled efficient intracellular delivery of nucleic acids and proteins. For nucleic acid delivery, plasmid DNA and mRNA were loaded to realize CRISPR/Cas 9 gene editing in vivo and protein expression in vivo, respectively. For protein delivery, the delivery system carrying OVA protein and CpG formed a nano-vaccine, which induced enhanced humoral and cellular immunity in vivo. In addition, the delivery system based on PEI1.8k revealed negligible cytotoxicity. This work provided a novel strategy to prepare efficient delivery systems based on cationic polymers via the introduction of a multifunctional enhancer.

Biomineralized Two-Enzyme Nanoparticles Regulate Tumor Glycometabolism Inducing Tumor Cell Pyroptosis and Robust Antitumor Immunotherapy.

Currently, immune checkpoint therapy combined with chemotherapy and radiotherapy is a useful strategy for improving immunotherapy's therapeutic efficacy. However, chemotherapy and radiotherapy cause serious side effects, so finding safe and effective methods to combine with immunotherapy is critical. In this work, regulating tumor glycometabolism is found to induce tumor cell pyroptosis and regulate the degree of expression of programmed death-ligand 1 (PD-L1). Therefore, how to treat tumors by regulating tumor glycometabolism in combination with anti-PD-L1 therapy is investigated here. First, the biomineralization-like method is used to construct nanoparticles with two-enzymatic activity by hybridizing nanozymes and glucose oxidase (GOx). It has the ability to self-amplify regulation of the glycometabolism of tumor cells. It can also induce tumor cell pyroptosis and increase the expression of PD-L1 in tumor cells. To treat tumors, nanoparticles are further combined with anti-PD-L1, which substantially inhibits tumor development and significantly increases  the survival time of mice. Combination therapy also has a significant immunological memory effect, successfully preventing tumor recurrence and metastasis. This is thought to be the first study that combines tumor glycometabolism with immunocheckpoint blocking in cancer therapy. This innovative, safe, low-toxic, and highly effective anti-tumor strategy can have good prospects in clinical applications.

Combining mannose receptor mediated nanovaccines and gene regulated PD-L1 blockade for boosting cancer immunotherapy.

Tumor nanovaccines have potential applications in the prevention and treatment of malignant tumors. However, it remains a longstanding challenge in exploiting efficient nanocarriers for inducing potent specifically cellular immune responses. Toward this objective, we herein explore an intensive tumor immunotherapeutic strategy by combining mannosylated nanovaccines and gene regulated PD-L1 blockade for immune stimulation and killing activity. Here, we fabricate a mannose modified PLL-RT (Man-PLL-RT) mediated nanovaccines with dendritic cells (DCs) targeting capacity. Man-PLL-RT is capable of co-encapsulating with antigen (ovalbumin, OVA) and adjuvant (unmethylated cytosine-phosphate-guanine, CpG) by electrostatic interaction. This positively charged Man-PLL-RT/OVA/CpG nanovaccines can facilitate the endocytosis, maturation and cross presentation in DCs. However, the nanovaccines arouse limited inhibition of tumor growth, which is mainly due to the immunosuppressed microenvironment of tumors. Combining tumor nanovaccines with gene regulated PD-L1 blockade leads to an obvious tumor remission in B16F10 melanoma bearing mice. The collaborative strategy provides essential insights to boost the benefits of tumor vaccines by regulating the checkpoint blockade with gene therapy.

A generally minimalist strategy of constructing biomineralized high-efficiency personalized nanovaccine combined with immune checkpoint blockade for cancer immunotherapy.

As a representative of tumor immunotherapy, tumor vaccine can inhibit tumor growth by activating tumor-specific immune response, which has the advantages of relatively low toxicity and high efficiency, and has attracted much attention in recent years. However, there are still difficulties in how to effectively deliver tumor vaccines in vivo and make them work efficiently. It is a relatively mature method to load tumor specific antigens with suitable carriers to produce tumor vaccines. Here, a generally minimalist construction method of tumor nanovaccine was developed. A high-efficiency tumor nanovaccine (NV) was prepared in one step by a biomineralization-like method, which contained ovalbumin (OVA, model antigen), unmethylated cytosine-phosphate-guanine (CpG, adjuvant) and Mn-NP (carrier and adjuvant). NV not only showed good tumor preventive effect, but also could successfully inhibited tumor development and metastasis when combined with anti-PD-L1, and induced long-term immune memory effect. However, the method of screening tumor specific antigen to construct nanovaccine is cumbersome and tumors are heterogeneous. Therefore, surgically resected tumor tissue is the best source of antigens for preparing tumor vaccines. Next, based on the strong loading ability of the carrier, we designed a personalized tumor nanovaccine (PNV) using the supernatant of tumor abrasive fluid (STAF) as antigen based on the generally minimalist tumor nanovaccine construction strategy. PNV combined with anti-PD-L1 could successfully inhibit post-surgical tumor recurrence and induce strong and durable immune memory effects. This study presents a novel, general, and minimalist strategy to construct high-efficiency personalized nanovaccine, which has a wide range of potential applications in the field of tumor treatment.

An immune cocktail therapy to realize multiple boosting of the cancer-immunity cycle by combination of drug/gene delivery nanoparticles.

Immune checkpoint blockade therapy (ICT) has shown potential in the treatment of multiple tumors, but suffers poor response rate in clinic. We found that even combining ICT with chemotherapy, which was wildly used in clinical trials, failed to achieve satisfactory tumor inhibition in the B16F10 model. Thus, we further constructed a previously unexplored immune cocktail therapy and realized multiple boosting of the cancer-immunity cycle. Cocktail therapy consisted of two kinds of tumor microenvironment-responsive drug and gene delivery nanoparticles to achieve specific delivery of doxorubicin and codelivery of plasmids expressed small hairpin RNA of PD-L1 (pshPD-L1) and hyaluronidase (pSpam1) in the tumor area. Experimental evidences proved that any component in the cocktail therapy was indispensable, and the cocktail therapy exhibited excellent antitumor effects against different types of tumors. The cocktail therapy presented here offers a searching strategy for more synergistic units with ICT and is meaningful for developing more efficient antitumor immunotherapy.