An updated overview of cyanidins for chemoprevention and cancer therapy.

Anthocyanins are colored polyphenolic compounds that belong to the flavonoids family and are largely present in many vegetables and fruits. They have been used in traditional medicine in many cultures for a long time. The most common and abundant anthocyanins are those presenting an O-glycosylation at C-3 (C ring) of the flavonoid skeleton to form -O-ß-glucoside derivatives. The present comprehensive review summarized recent data on the anticancer properties of cyanidings along with natural sources, phytochemical data, traditional medical applications, molecular mechanisms and recent nanostrategies to increase the bioavailability and anticancer effects of cyanidins. For this analysis, in vitro, in vivo and clinical studies published up to the year 2022 were sourced from scientific databases and search engines such as PubMed/Medline, Google scholar, Web of Science, Scopus, Wiley and TRIP database. Cyanidins' antitumor properties are exerted during different stages of carcinogenesis and are based on a wide variety of biological activities. The data gathered and discussed in this review allows for affirming that cyanidins have relevant anticancer activity in vitro, in vivo and clinical studies. Future research should focus on studies that bring new data on improving the bioavailability of anthocyanins and on conducting detailed translational pharmacological studies to accurately establish the effective anticancer dose in humans as well as the correct route of administration.

Nano-targeting vascular remodeling in cancer: Recent developments and future directions.

Tumor growth and progression are strictly dependent on the adequate blood supply of oxygen and nutrients. The formation of new blood vessels and vascular networks is essential to ensure this demand. Blood vessels also facilitate the invasion of cancer cells into nearby tissues and their subsequent metastasis. Tumor cells represent the main driver of the neovascularization process through the direct or indirect, by neighboring non-cancer cells, release of pro-angiogenic molecules. The mediators (e.g., growth factors and extracellular matrix components), signaling pathways, cellular components, and processes (e.g., endothelial cell proliferation and migration) activated in tumor angiogenesis are similar to those involved in normal vascular development, except they lack efficient control mechanisms. Consequently, newly formed tumor vessels are typically fragile and hyperpermeable with a reduced and erratic blood flow. Targeting the tumor vasculature has been the focus of intense research over the last 20 years. However, despite the initial interest and expectations, the systemic use of anti-angiogenic drugs has not always led to therapeutic breakthroughs and, in some cases, has been associated with the development of tumor adaptive resistance resulting in a more aggressive phenotype. Therefore, new therapeutic approaches have focused on combining anti-angiogenic agents with chemotherapy or immunotherapy and/or optimizing (normalizing) the structure and function of tumor blood vessels to ensure a more efficient drug delivery. In this context, nanomedicine offers the significant advantage of targeting and releasing anti-angiogenic drugs at specific sites, minimizing toxicity in healthy tissues. Several nanoparticles possess intrinsic modulatory effects on angiogenesis, while others have been developed to facilitate drug delivery in association with chemotherapy, thermotherapy, radiotherapy or in response to specific stimuli within the tumor environment (e.g., enzymes, ions, redox potential) or exogenous stimuli (e.g., temperature, electricity, magnetic fields, and ultrasound). Other nanoparticles can modify, under specific conditions, their physical properties (e.g., dimensions, structure, and interactions) to increase penetration in tumor cells. This review provides a comprehensive appraisal of the critical modulators of tumor vascular biology, the most promising nano-strategies that specifically target such modulators, and the directions for future research and clinical applications.