Layered double hydroxides (LDHs) nanomaterial is a two-dimensional nanomaterial with a multi-layer structure. Due to their unique structural composition, LDHs can act as a "molecular switch" to achieve controllable release of payload under specific physiological pH conditions while remaining stable during blood circulation. In addition, LDHs are composed of several specific cations and have specific regulatory effects on various cellular functions. In addition to the excellent drug loading performance, LDHs can respond to the tumor microenvironment and realize a smart release of drugs, reduce the side effects of drugs, and enhance the tumor killing effect, having a wide range of applications in the field of tumor therapy. In this paper, the research progress of LDHs for chemotherapy drug delivery, immunotherapy, photodynamic therapy, and immunocombination therapy for tumors was reviewed.

Immunotherapy, which utilizes the body’s own immune system to fight cancer, has become one of the mainstream clinical strategies for cancer treatment, and the number of immunotherapeutic drugs approved for clinical treatment has increased year by year. However, the tumor microenvironment with immunosuppressive ability significantly reduces the effect of immunotherapy, making immunotherapy suffer from low response rate, poor penetration, and other problems, and the clinical efficacy is not ideal. In this review paper, the methods and mechanisms of action of remodeling the immunosuppressive tumor microenvironment (ITME) by reducing immunosuppressive cells and soluble molecules were summarized, and the important role of combined chemotherapy, radiotherapy, and other therapeutic modalities was explored in remodeling the ITME and enhancing the efficacy of immunotherapy.

Tumor immunotherapy has become the main treatment method for cancer after surgery, radiotherapy and chemotherapy. With the in-depth study of tumor immunology, cell biology and molecular technology, the tumor microenvironment was found to be immunosuppressive, and tumor development and metastasis are closely related to it. Tumor immunotherapy uses the body’s own immune system to kill tumor cells. At present, there are mainly mainstream tumor immunotherapy methods, namely monoclonal antibody therapy, immune checkpoint inhibitor therapy, immunocell therapy, and tumor vaccines. In this paper, the advantages and limitations of these four immunotherapies were mainly discussed, and the current status of their marketing and clinical research was also reviewed.

Neutrophils are the most abundant population of white blood cells in the human circulation. They play a key role in the protection of the host against microbial infections as well as taking a critical part in inflammatory processes. Recently, several studies showed that neutrophils play an active role in the immune response during cancer development. Neutrophils and various immune cells constitute a significant part of the tumor immune microenvironment. Research has found that different subpopulations of neutrophils may promote or limit tumor growth, indicating that people should be more concerned about the potential of neutrophils. In this paper, the various functions of neutrophils in the progression and treatment of cancer and the possibility of using these functions as a new model of immunotherapy were reviewed.

Hydrogels are hydrophilic three-dimensional networks that exhibit soft and flexible textures after absorbing water, making them biocompatible and biodegradable. Due to their similarity to biological tissues, hydrogels find extensive applications in the field of biomedical mechanism. In this paper, the preparation methods of physical hydrogels and chemical hydrogels are introduced according to the different cross-linking agents, and the application progress of hydrogels in cell therapy is reviewed.

The immune system is involved in the initiation and progression of cancer. Research on cancer and immunity has contributed to the development of several clinically successful immunotherapies. These immunotherapies often act on a single step of the cancer-immunity cycle. In recent years, the discovery of new nanomaterials has dramatically expanded the functions and potential applications of nanomaterials. In addition to acting as drug-delivery platforms, some nanomaterials can induce the immunogenic cell death (ICD) of cancer cells or regulate the profile and strength of the immune response as immunomodulators. Based on their versatility, nanomaterials may serve as an integrated platform for multiple drugs or therapeutic strategies, simultaneously targeting several steps of the cancer-immunity cycle to enhance the outcome of anticancer immune response. To illustrate the critical roles of nanomaterials in cancer immunotherapies based on cancer-immunity cycle, this review will comprehensively describe the crosstalk between the immune system and cancer, and the current applications of nanomaterials, including drug carriers, ICD inducers, and immunomodulators. Moreover, this review will provide a detailed discussion of the knowledge regarding developing combinational cancer immunotherapies based on the cancer-immunity cycle, hoping to maximize the efficacy of these treatments assisted by nanomaterials.

Chemotherapy has been a major option in clinic treatment of malignant tumors. However, single chemotherapy faces some drawbacks, such as multidrug resistance, severe side effects, which hinder its clinic application in tumor treatment. Multifunctional nanoparticles loading with chemotherapeutic agent and photosensitizer could be a promising way to efficiently conduct tumor combination therapy. In the current study, a novel pH-sensitive and bubble-generating mesoporous silica-based drug delivery system (denoted as M(a)D@PI-PEG-RGD) was constructed. Ammonium bicarbonate (NH

Malignant tumors are the second most important cause of death after cardiovascular and cerebrovascular diseases. Chemotherapeutic drugs for tumor treatment have strong toxic side effects. The common solution is to use nanoparticle as a carrier that can deliver drugs to tumor issues so as to kill the tumor cells. However, most of the current drug-carriers have a serious drug loss before reaching the tumor area, which makes the difficult control of drug release. Multi-stimulus responsive nano-carrier systems can overcome these drawbacks and make drug release controllable. pH/redox dual sensitive nano-carrier systems are currently hot research direction. In this paper, the research progress of pH/redox dual sensitive nano-carrier systems in recent years was reviewed in order to provide reference for relative researches.

In recent years, mesoporous silica nanoparticles (MSNs) have been widely used in the construction of various intelligent drug delivery systems due to their unique and excellent properties. The stimuli-responsive drug delivery system based on mesoporous silica nanoparticles can effectively load anticancer drugs and target them to tumor cells, and then responsively release anticancer drugs under the action of specific stimulation signals. The method of specifically delivering anticancer drugs to target sites not only can greatly improvethe drug efficacy, but also effectively reduce the side effects of anticancer drugs on normal tissues and organs. Thereby the advantages of anticancer drugs in tumor therapy are improved. In this paper, the applications and developments of stimuliresponsive mesoporous silica nano drug delivery systems in tumor therapy were summarized.

In recent years,the incidence of malignant tumors continually increased with the trend of younger age in onset age,which pose a serious threat to human health.At present,there are a variety of clinical anti-tumor treatments.However,a single treatment usually cannot achieve the best therapeutic effect.As a result,the combination therapy is often used in clinical practice.Combination therapy not only can enhance the therapeutic effect and reduce the toxic side effects of drugs,but also can alleviate the pain of patients.Chemotherapy is a commonly used clinical treatment for tumors.However,it can lead to greater side-effects,and cause irreversible damage to normal cells while killing the tumor cells.Photodynamic therapy uses the specific wavelengths of light to excite and activate the photosensitizer enriched in the tumor local.As a result,the tumor cells are killed directly or indirectly by photodynamic reactions with the participation of internal oxygen.Tumorassociated antigen will appear following the chemotherapy or photodynamic therapy.The immune system will stimulate the body to produce specific anti-tumor immune response after identifying the tumor-associated antigens.The combination treatment of chemotherapy and photodynamic therapy combined with immunotherapy not only can effectively improve the treatment effect of chemotherapy drugs and reduce drug side effects,inhibit tumor metastasis,but also can induce the production long-term anti-tumor immune response,so as to maximize the treatment effect.In this paper,the progress of the researches on chemotherapy,photodynamic therapy and immunotherapy in recent years were summarized.