Imaging tumor hypoxia:Blood-borne delivery of imaging agents is fundamentally different in hypoxia subtypes

Dedicated to the memory of Professor Briton Chance on the ccasion of his 100th birthday(July24 th,2013),and remembering mary erciting discussions on the orygenation of breast cancer,ontumor hyporia in general and imaging of the orygenation status of malignant tumors.Hypoxic tissue subvolumes are a hallmark feat ure of solid malignant tumors,relevant for cancertherapy and patient outcome because they increase both the intrinsic aggressiveness of tumor cells and their resist ance to several commonly used anticancer strategies.Pathogenetic mech-anisms leading to hypoxia are diverse,may coexist within the same tumor and are commonlygrouped according to the duration of their ffects.Chronic hypoxia is mainly caused by difusionlimitations resulting from enlarged intercapilary distances and adverse difusion geometriesand--to a lsser extent--by hypoxemia,compromised perfusion or long-lasting microregionalfow stops.Conversely,acute hypoxia preferentilly results from transient disruptions in per.fusion.While each of these features of the tumor microenvironment can contribute to a criticalreduction of oxy gen availability,the delivery of imaging agents(as well as nutrients and anti-cancer agents)may be compromised or remain unaffected,Thus,a critial appraisal of the ffectsof the various mechanisms leading to hypoxia with regard to the blood-bome delivery of imagingagents is necessary to judge their ability to correctly represent the hypoxic phenotype of solidmalignancies.

A 3-D in vitro tumor model for investigation of bacteria-mediated gene delivery

Introduction Cancer is an attractive target of gene therapy and currently represents the disease in most clinical trials[1]. Strategies for cancer gene therapy include: (1) stimulation of immune responses to tumor cells,(2) delivery of specific enzymes

Molecularly engineered truncated tissue factor with therapeutic aptamers for tumor-targeted delivery and vascular infarction

Selective occlusion of tumor vasculature has proven to be an effective strategy for cancer therapy.Among vascular coagulation agents,the extracellular domain of coagulation-inducing protein tissue factor,truncated tissue factor(tTF),is the most widely used.Since the truncated protein exhibits no coagulation activity and is rapidly cleared in the circulation,free tTF cannot be used for cancer treatment on its own but must be combined with other moieties.We here developed a novel,tumor-specific tTF delivery system through coupling tTF with the DNA aptamer,AS1411,which selectively binds to nucleolin receptors overexpressing on the surface of tumor vascular endothelial cells and is specifically cytotoxic to target cells.Systemic administration of the tTF-AS1411 conjugates into tumor-bearing animals induced intravascular thrombosis solely in tumors,thus reducing tumor blood supply and inducing tumor necrosis without apparent side effects.This conjugate represents a uniquely attractive candidate for the clinical translation of vessel occlusion agent for cancer therapy.

The progress and perspective of nanoparticle-enabled tumor metastasis treatment

As one of the most serious threats to human being,cancer is hard to be treated when metastasis happens.What’s worse,there are few identified targets of metastasis for drug development.Therefore,it is important to develop strategies to prevent metastasis or treat existed metastasis.This review focuses on the procedure of metastasis,and first summarizes the targeting delivery strategies,including primary tumor targeting drug delivery,tumor metastasis targeting drug delivery and hijacking circulation cells.Then,as a promising treatment,the application of immunotherapy in tumor metastasis treatment is introduced,and strategies that stimulating immune response are reviewed,including chemotherapy,photothermal therapy,photodynamic therapy,ferroptosis,sonodynamic therapy,and nanovaccines.Finally,the challenges and perspective about nanoparticle-enabled tumor metastasis treatment are discussed.