Liposomes, the most widely studied nano-drug carriers in drug delivery, are sphere-shaped vesicles consisting of one or more phospholipid bilayers. Compared with traditional drug delivery systems, liposomes exhibit prominent properties that include targeted delivery, high biocompatibility, biodegradability, easy functionalization, low toxicity, improvements in the sustained release of the drug it carries and improved therapeutic indices. In the wake of the rapid development of nanotechnology, the studies of liposome composition have become increasingly extensive. The molecular diversity of liposome composition, which includes long-circulating PEGylated liposomes, ligand-functionalized liposomes, stimuli-responsive liposomes, and advanced cell membrane-coated biomimetic nanocarriers, endows their drug delivery with unique physiological functions. This review describes the composition, types and preparation methods of liposomes, and discusses their targeting strategies in cancer therapy.

The therapeutic efficiency of sonodynamic therapy (SDT) mainly depends on the presence of oxygen (O₂) to generate harmful reactive oxygen species (ROS); thus, the hypoxic tumor microenvironment significantly limits the efficacy of SDT. Therefore, the development of oxygen-independent free radical generators and associated combination therapy tactics can be a promising field to facilitate the anticancer capability of SDT. In this study, a biomimetic drug delivery system (C-TiO₂/AIPH@PM) composed of an alkyl-radical generator (2,2′-azobis[2-(2-imidazolin-2-yl)propane] dihydrochloride, AIPH)-loaded C-TiO₂ hollow nanoshells (HNSs) as the inner cores, and a platelet membrane (PM) as the outer shells is successfully prepared for synergistic SDT and oxygen-independent alkyl-radical therapy. The PM encapsulation can significantly prolong the blood circulation time of C-TiO₂/AIPH@PM compared with C-TiO₂/AIPH while enabling C-TiO₂/AIPH@PM to achieve tumor targeting. C-TiO₂/AIPH@PM can efficiently produce ROS and alkyl radicals, which can achieve a more thorough tumor eradication regardless of the normoxic or hypoxic conditions. Furthermore, the generation of these radicals improves the efficiency of SDT. In addition, nitrogen (N₂) produced due to the decomposition of AIPH enhances the acoustic cavitation effect and lowers the cavitation threshold, thereby enhancing the penetration of C-TiO₂/AIPH@PM at the tumor sites. Both in vitro and in vivo experiments demonstrate that C-TiO₂/AIPH@PM possesses good biosafety, ultrasound imaging performance, and excellent anticancer efficacy. This study provides a new strategy to achieve oxygen-independent free radical production and enhance therapeutic efficacy by combining SDT and free radical therapy.

Histopathological examination (biopsy) is the “gold standard” for the diagnosis of colorectal cancer (CRC). However, biopsy is an invasive method, and due to the temporal and spatial heterogeneity of the tumor, a single biopsy cannot reveal the comprehensive biological characteristics and dynamic changes of the tumor. Therefore, there is a need for new biomarkers to improve CRC diagnosis and to monitor and treat CRC patients. Numerous studies have shown that “liquid biopsy” is a promising minimally invasive method for early CRC detection. A liquid biopsy mainly samples circulating tumor cells (CTCs), circulating tumor DNA (ctDNA), microRNA (miRNA) and extracellular vesicles (EVs). CTCs are malignant cells that are shed from the primary tumors and/or metastases into the peripheral circulation. CTCs carry information on both primary tumors and metastases that can reflect dynamic changes in tumors in a timely manner. As a promising biomarker, CTCs can be used for early disease detection, treatment response and disease progression evaluation, disease mechanism elucidation, and therapeutic target identification for drug development. This review will discuss currently available technologies for plasma CTC isolation and detection, their utility in the management of CRC patients and future research directions.

In Chinese traditional medicine, quercetin (QT) plays a fundamental role in the treatment of asthma, as an anti-allergen and to lower blood pressure. Recent evidence suggests that QT can improve tumor radiosensitivity through multiple mechanisms. However, poor tumor tissue targeting ability and low water solubility of QT limit its usefulness in the treatment of cancers. Herein, we designed a novel drug delivery system (CQM) consisting of inner QT loaded mesoporous silica nanoparticles (MSNs) and outer cancer cell membranes (CM). The developed nanoplatform had strong anti-cancer effects under X-ray irradiation and good QT loading characteristics. In addition, CQM effectively targeted tumor tissues. Results of in vitro and in vivo experiments demonstrated that the developed CQM drug delivery system has excellent tumor targeting ability and effectively inhibited tumor growth. Therefore, the CQM platform realized targeted drug delivery and radiotherapy sensitization, which provided a newfangled idea of cancer treatment.

Sonosensitizer-mediated sonodynamic therapy (SDT) has emerged as a promising anti-tumor strategy. However, this strategy of continuous oxygen consumption further exacerbates the hypoxic tumor microenvironment, which limits its therapeutic efficacy. In this study, we designed a multifunctional hydrogel (PB+Ce6@Hy) that simultaneously co-delivers nanozyme prussian blue (PB) and sonosensitizer chlorin e6 (Ce6) for the realization of photothermal therapy (PTT) and enhanced SDT. When the hydrogel reaches the tumor tissue through local injection, the 808 nm laser can induce the hydrogel to warm up and soften, thereby triggering the release of PB and Ce6. PB can interact with endogenous H₂O₂in situ and generate sufficient oxygen to promote the Ce6-mediated SDT effect. Besides, due to the good encapsulation ability of the hydrogel, the nanomaterials can be released in a controlled manner by changing laser parameter, irradiation time, etc. The experimental results show that the PB+Ce6@Hy system we developed can generate a large amount of reactive oxygen species (ROS), which can be combined with the photothermal effect to kill tumor cells, as a result, tumor proliferation has been adequately inhibited. This combined PTT/SDT dynamic strategy provides a new perspective for Ce6-induced cancer therapy, showing great potential for clinical application.