The development of nanotechnology has made it possible to develop safe, efficient, precise and controllable drug delivery system (DDS). Among them, organic or inorganic synthetic nanocarriers have been widely reported and used for the delivery of tumor therapeutic agents. However, some of carriers have several problems, such as easily eliminated by the body's immune system, difficult to preparation or poor safety in vivo. In recent years, with the development of biomedicine, biomimetic technology based biomembrane-mediated nanodrug delivery has organically integrated the low immunogenicity of natural biomembrane, cancer targeting, and the controllable and multifunctional of smart nanocarrier design. It will achieve a new breakthrough of nanotechnology in cancer targeted therapy. Based on the recent advances of cell membrane-derived biomimetic nanotechnology and the nanomedicine in the field of cancer therapy, this review discusses the three aspects including the experimental basis of cell membrane-derived biomimetic nanotechnology, the classification of biomimetic nanodrug delivery platforms, and the application in cancer targeted therapy. Therefore, the review will provide reference for the design of smart drug delivery system and its development in cancer targeted treatment.

As a basic amino acid, histidine has a pK_a close to the acidity of the tumor microenvironment, thus the charge and solubility of histidine are able to vary as the pH changes. Under a neutral environment, histidine is not charged and exhibits hydrophobic properties, while it can be protonated and becomes hydrophilic when exposed to mildly acidic pH, such as tumor microenvironment. Therefore, histidine is widely used in the design of drug delivery systems to target the mildly acidic pH of tumor microenvironment. This article reviews the recent progresses of histidine-based tumor-targeting drug delivery systems, and summarizes the principles on promoting internalization and tuning drug release by taking advantage of histidine. Finally, we point out the common issues on histidine application and illustrate its future prospects.

Chemoimmunotherapy has attracted much attention as an emerging therapy pattern for the treatment of cancers. Exploring effective drug combination schemes and reasonable delivery methods remained the key issue in current research. Herein, we designed sorafenib (SF) and anti-Tim-3 monoclonal antibody (Tim-3 mAb) co-loaded MMP2-responsive mesoporous silica nanoparticles (ST-MSNs) for combined chemoimmunotherapy of hepatocellular carcinoma (HCC). The shell of ST-MSNs was fabricated by Tim-3 mAb through matrix metalloproteinase 2 (MMP2) sensitive peptides as "gatekeepers" to prevent drug release during the blood circulation. In tumor microenvironment, the high levels of MMP2 caused the responsive shedding of Tim-3 mAb, leading to the triggerred release of SF and Tim-3 mAb. Then, SF could be delivered to tumor cells and Tim-3 mAb could be delivered to T cells, respectively. In vivo tumor inhibition study results demonstrated that ST-MSNs can significantly enhance synergistic antitumor activity compared with sequential administration of free SF solution and Tim-3 mAb solution. Meanwhile, the expression of antitumor cytokines IFN-γ, IL-12 and the percentage of CD3⁺CD4⁺ cells, CD3⁺CD8⁺ cells in tumors were upregulated after the administration of ST-MSNs, demonstrating good immunomodulatory ability. In addition, within the dosage range, the ST-MSNs had low cytotoxicity and hemolysis, and no obvious tissue toxicity was observed. All animal experiments were performed in line with national regulations and approved by the Animal Experiments Ethical Committee of Shandong University. In conclusion, this study provided a promising drug combination of chemoimmunotherapy with good application prospects for clinical HCC treatment, and exhibited a potential drug carrier for clinical chemoimmunotherapy.

In recent years, immunotherapy has made great progress in clinical cancer therapy. However, the poor tumor specificity, low intra-tumoral penetration, and low cellular uptake in the systemic delivery of immunotherapeutic drugs lead to low efficacy and poor safety, limiting the development of immunotherapy. Active tumor-targeting nano drug delivery systems (aNDDS) can enhance the concentration of drugs in target cells through the interaction between surface-conjugated antibodies or ligands and the receptors on target cell membranes, providing a viable strategy for specific and efficient drug delivery. In addition, some specific types of cell membranes with the natural targeting ability have been exploited for the construction of biomimetic nanocarriers to improve the drug delivery efficiency. In view of the many advantages of active tumor-targeting nanocarriers, researchers also have designed a series of aNDDS for promoting antitumor immune responses and proved that they improved the efficacy and safety of immunotherapy. In this review, we summarize the recent progress on aNDDS for improving the tumor immunotherapy and look forward to the main challenges and future directions in this field.

Polydopamine (PDA) is a novel type of polymer synthesized inspired by adhesion proteins in mussels. It has been widely used in tumor-targeting drug delivery systems due to its natural advantages such as good biocompatibility, excellent photothermal conversion performance, adhesion, high chemical reactivity and multiple drug release response mechanisms. This review summarizes the applications of PDA-based tumor-targeting drug delivery in recent years, hoping to provide references for designing a more reasonable and effective PDA-based multifunctional collaborative tumor therapy platform.

At present, cancer is still one of the most serious threats to human health. Despite the wide application of multiple cancer therapies in clinical practice, the therapeutic effects of most cancers are still far from satisfactory. In recent years, the discovery of regulated cell death may be a good first step on the road to treat cancer. Ferroptosis is triggered by lipid peroxidation of unsaturated fatty acids in cell membrane catalyzed by iron ion. It has been widely concerned as an emerging target for cancer therapy. With the booming of biomedical nanotechnology, ferroptosis as an emerging therapeutic target has attracted extensive attention. Here, we review the advance on the intersection of ferroptosis and biomedical nanotechnology. First, the research background of ferroptosis and nano-preparation as well as the feasibility of ferroptosis-based nano-drug delivery systems (nano-DDS) for cancer treatment are presented and analyzed. Then, the strategies for inducing ferroptosis based on nano-DDS are summarized, mainly including: the promotion of Fenton reaction, the inhibition of glutathione peroxidase 4 (GPX-4) and the restriction of the cysteine-glutamate exchange transporter (system Xc^-). Furthermore, the combination therapy strategies based on biomedical nanotechnology induced ferroptosis are also discussed. Finally, we shine the spotlight on the prospects and challenges of ferroptosis-based nanotherapeutics in clinical application.

Natural killer (NK) cells, as an essential part of innate immunity, can directly identify and kill tumor cells after being activated by the synergistic action of surface inhibitory receptors and activated receptors. It can secrete cytokines to recruit dendritic cells (DCs), induce DCs maturation and enhance adaptive immune response. It can target cancer stem cells (CSCs) and circulating tumor cells (CTCs) to inhibit cancer metastasis. NK cells have a unique inflammatory tendency, which can respond to cytokines and chemokines released from tumor sites and migrate to tumor sites, making them occupy an important advantage in cancer targeted therapy. The research on cancer targeted therapy of NK cells as drug delivery carriers, NK cell membrane-coated biomimetic nanoparticles, and NK cell extracellular vesicles (NKEVs) has attracted more and more attention. The article will focus on the mechanism of NK cells inhibiting cancer, and summarize the research progress of cancer targeted therapy of NK cells.

This paper aims to develop folic acid-modified paclitaxel nanocrystals (PTX NC@FA) with good stability, high drug loading and tumor cell targeting for endoscopic injection for preoperative local chemotherapy of gastric cancer. PTX NC@FA was prepared by the "bottom-up" followed by ultrasonic to study its morphology, particle size, ζ-potential, drug loading, folic acid-modified phospholipid (FA-DSPE-PEG₂₀₀₀) content, crystalline characteristics, stability, in vitro release, cytotoxicity against human gastric cancer cell line SGC-7901, and anti-tumor effect in two different tumor sizes (tumor volume 100 mm³ or 300 mm³) after single peri-tumor injection in a murine subcutaneous SGC-7901 tumor model. Animal experiments were approved by the Experimental Animal Ethics Committee of the School of Pharmacy, Fudan University. The resulting PTX NC@FA was of short rod-like shape, average particle size 175.3±2.5 nm (PDI 0.17±0.02), ζ-potential -2.5±0.2 mV, PTX loading (28.23±0.74)% (w/w) and FA-DSPE-PEG₂₀₀₀ content (4.40±0.60)% (w/w). The size of the PTX NC@FA remained unchanged for 4 days in phosphate buffer with or without serum. Cellular growth inhibition effect on SGC-7901 showed the superiority of PTX NC@FA over nanocrystals without FA modification. PTX NC@FA inhibited tumor growth more efficiently than both nanocrystals without FA modification and commercially available paclitaxel injection (Taxol) 12 days after peri-tumor injection. For model tumor with the volume of 100 mm³, tumors of all animals in the PTX NC@FA group disappeared completely. For model tumor with the volume of 300 mm³, tumors of 3 animals in the PTX NC@FA group completely disappeared and tumors of the rest 4 animals also became significantly smaller with a tumor volume inhibition rate of 90%. PTX NC@FA showed good potential for preoperative chemotherapy of increase the chances of function preserving gastrectomy and improve the quality of life of patients.

The neonatal Fc receptor (FcRn) was first found to be a membrane protein that maternal antibodies transmitted to fetuses and newborns, and also expressed in multiple organs and tissues for whole life in adults. It plays a significant role to central regulate the lifespan of immunoglobulin G and serum albumin, as well as its involvement in innate and adaptive immune responses. In modern biopharmaceuticals, FcRn is a great potential drug delivery target and a highlighted subject for current research. This paper briefly describes the basic biological properties and action mechanism of FcRn, as well as the commonly used drug carrier design strategies of FcRn, especially the functional applications of prolonging half-life, targeted drug delivery, transmembrane and antigen presentation and so on. We propose that these distribution in different tissues and the diverse biological activities may have significant implications of targeting FcRn for novel drug delivery systems and immunotherapy.

Tumor immune checkpoint therapy is a clinical treatment strategy developed based on the new principle of the inhibition of negative immune regulation. In this article, the tumor immune checkpoint therapy and the drug delivery strategies were reviewed, mainly including immunity and tumor therapy, tumor immune checkpoint therapy and its mechanism of action, clinical application of tumor immune checkpoint therapy and therapeutic drugs, immune resistance of programmed cell death protein 1 (PD1)/programmed cell death ligand 1 (PDL1) treatment and countermeasures, drug delivery strategies for tumor immune checkpoint therapeutic agents, etc. As a revolutionary new immunotherapy strategy, tumor immune checkpoint therapy has shown obvious superior therapeutic efficacy in a variety types of tumor. However, tumor immune checkpoint therapy is also faced with a big challenge, namely, immunotherapy resistance. With the discovery of new mechanism, the continuous development of new therapeutic drugs and delivery strategies, tumor immune checkpoint therapy is expected to further improve the clinical efficacy of tumor.