Effective tumor vessel barrier disruption mediated by perfluoro-N-(4-methylcyclohexyl) piperidine nanoparticles to enhance the efficacy of photodynamic therapy

Enzyme-Induced Shape-Shifting Peptide Nanocarrier Coloaded with Paclitaxel and Dipyridamole Inhibits Platelet Function and Tumor Metastasis

Tumor-associated platelets can bind to tumor cells and protect circulating tumor cells from NK-mediated immune surveillance. Tumor-associated platelets secrete cytokines to induce the epithelial-mesenchymal transition (EMT) in tumor cells, which promotes tumor metastasis. Combining chemotherapeutic agents with antiplatelet drugs can reduce the occurrence of metastasis, but the systemic application of chemotherapeutic agents and antiplatelet drugs is prone to causing serious side effects. Therefore, delivering drugs to the tumor microthrombus site for long-lasting inhibition is a problem that needs to be addressed. Here, we show that small molecule peptide nanoparticles containing the Cys-Arg-Glu-Lys-Ala (CREKA) peptide can deliver the platelet inhibitor dipyridamole (DIP) and the chemotherapeutic drug paclitaxel (PTX) to tumor tissues, thereby inhibiting tumor-associated platelet function while killing tumor cells. The drug-loaded nanoparticles PD/Pep1 inhibited platelet-tumor cell interactions, were effectively taken up by tumor cells, and underwent morphological transformation induced by alkaline phosphatase (ALP) to prolong the retention time of the drugs. After intravenous injection, PD/Pep1 can target tumors and inhibit tumor metastasis. Thus, this small molecule peptide nanoformulation provides a simple strategy for efficient drug delivery and shows promise as a novel cancer therapy platform.

Recent progress, perspectives, and issues of engineered PD-L1 regulation nano-system to better cure tumor: A review

Currently, immune checkpoint blockade (ICB) therapies that target the programmed cell death ligand-1 (PD-L1) have been used as revolutionary cancer treatments in the clinic. Apart from restoring the antitumor response of cytotoxic T cells by blocking the interaction between PD-L1 on tumor cells and programmed cell death-1 (PD-1) on T cells, PD-L1 proteins were also newly revealed to possess the capacity to accelerate DNA damage repair (DDR) and enhance tumor growth through multiple mechanisms, leading to the impaired efficacy of tumor therapies. Nevertheless, current free anti-PD-1/PD-L1 therapy still suffered from poor therapeutic outcomes in most solid tumors due to the non-selective tumor accumulation, ineludible severe cytotoxic effects, as well as the common occurrence of immune resistance. Recently, nanoparticles with efficient tumor-targeting capacity, tumor-responsive prosperity, and versatility for combination therapy were identified as new avenues for PD-L1 targeting cancer immunotherapies. In this review, we first summarized the multiple functions of PD-L1 protein in promoting tumor growth, accelerating DDR, as well as depressing immunotherapy efficacy. Following this, the effects and mechanisms of current clinically widespread tumor therapies on tumor PD-L1 expression were discussed. Then, we reviewed the recent advances in nanoparticles for anti-PD-L1 therapy via using PD-L1 antibodies, small interfering RNA (siRNA), microRNA (miRNA), clustered, regularly interspaced, short palindromic repeats (CRISPR), peptide, and small molecular drugs. At last, we discussed the challenges and perspectives to promote the clinical application of nanoparticles-based PD-L1-targeting therapy.

Metabolic reprogramming mediated PD-L1 depression and hypoxia reversion to reactivate tumor therapy

As a promising cancer treatment, photodynamic therapy (PDT) still achieved limited clinical success due to the severe hypoxia and programmed death ligand-1 (PD-L1) over-expressed immunosuppression tumor microenvironment. At present, few methods have been proven to solve these two defects simply and effectively by a single drug or nano-system simultaneously. To ameliorate this situation, we designed and constructed MB@Bu@MnO₂ nanoparticles with two-step oxygen regulation ability and PD-1/PD-L1 axis cascade-disruption capacity via a biomineralization method. In such a nanosystem, manganese dioxide albumin (MnO₂@Alb) was used as the drug carrier, Butformin (Bu) as mitochondria-associated oxidative phosphorylation (OXPHOS) disruption agent with PD-L1 depression and oxygen reversion ability, and methylene blue (MB) as PDT drug with programmed cell death protein 1 (PD-1) inhibition capacity. Owing to the tumor-responsive capacity of MB@Bu@MnO₂ nanoparticles, Bu and MB were selectively delivered and released in tumors. Then, the tumor hypoxia was dramatically reversed by Bu inhibited oxygen consumption, and MnO₂ improved oxygen generation. Following this, the reactive oxygen species (ROS) generation was enhanced by MB@Bu@MnO₂ nanoparticles mediated PDT owing to the reversed tumor hypoxia. Furthermore, the immunosuppression microenvironment was also obviously reversed by MB@Bu@MnO₂ nanoparticles enhanced immunogenic cell death (ICD) and PD-1/PD-L1 axis cascade-disruption, which then enhanced T cell infiltration and improved its tumor cell killing ability. Finally, the growth of solid tumors was significantly depressed by MB@Bu@MnO₂ nanoparticles mediated PDT. All in all, this well-designed nanosystem could solve the defects of traditional PDT via PD-1/PD-L1 axis dual disruption and reversing tumor hypoxia by two-step oxygen regulation.

Ethidium bromide-bridged mesoporous silica hybrid nanocarriers for fluorescence cell imaging and drug delivery applications

We report the fabrication of mesoporous organosilica hybrid nanocarriers with red-fluorescence behaviour under UV-light for pH-responsive drug delivery and red-fluorescence-based bioimaging applications in cancer therapy.