Smart Targeting To Improve Cancer Therapeutics.

Cancer is the second largest cause of death worldwide with the number of new cancer cases predicted to grow significantly in the next decades. Biotechnology and medicine can and should work hand-in-hand to improve cancer diagnosis and treatment efficacy. However, success has been frequently limited, in particular when treating late-stage solid tumors. There still is the need to develop smart and synergistic therapeutic approaches to achieve the synthesis of strong and effective drugs and delivery systems. Much interest has been paid to the development of smart drug delivery systems (drug-loaded particles) that utilize passive targeting, active targeting, and/or stimulus responsiveness strategies. This review will summarize some main ideas about the effect of each strategy and how the combination of some or all of them has shown to be effective. After a brief introduction of current cancer therapies and their limitations, we describe the biological barriers that nanoparticles need to overcome, followed by presenting different types of drug delivery systems to improve drug accumulation in tumors. Then, we describe cancer cell membrane targets that increase cellular drug uptake through active targeting mechanisms. Stimulus-responsive targeting is also discussed by looking at the intra- and extracellular conditions for specific drug release. We include a significant amount of information summarized in tables and figures on nanoparticle-based therapeutics, PEGylated drugs, different ligands for the design of active-targeted systems, and targeting of different organs. We also discuss some still prevailing fundamental limitations of these approaches, eg, by occlusion of targeting ligands.

Data on cytotoxic pattern of cholesterol analogs for lung adenocarcinoma cells.

Cholesterol (Cho) is a sterol that plays an essential role in the maintenance of biologic cell membranes, and various lipoproteins are its carriers through blood circulation [1]. Some FDA-approved anticancer drugs (i.e., Lipoplatin and Myocet) are conjugated to Cho moieties to improve their pharmacokinetic properties, cellular uptake and target specificity [2]. Recently natural and synthetic sterol compounds have shown a broad spectrum of pharmacological activities [3,4]. Herein, we investigated the anticancer activity of various natural Cho analogs, ie. asiatic acid (AsA), betulinic acid (BeA), oleanolic acid (OleA), ursolic Acid (UrA), lupeol (Lupe) and ß-sitosterol (ß-Sito) against non-small cell lung adenocarcinoma (A549). We performed theoretical calculations of the biophysicochemical properties, and viability assays in a range of 5-100 µM in A549 cells of these Cho analogs. We used ChemSketch and ChemSpider to determine physical properties, and GraphPad Prism 8 software for the data analysis to determine the inhibitory concentrations at 50% (IC50) of each compound.

Fueling a Hot Debate on the Application of TiO2 Nanoparticles in Sunscreen.

Titanium is one of the most abundant elements in the earth's crust and while there are many examples of its bioactive properties and use by living organisms, there are few studies that have probed its biochemical reactivity in physiological environments. In the cosmetic industry, TiO2 nanoparticles are widely used. They are often incorporated in sunscreens as inorganic physical sun blockers, taking advantage of their semiconducting property, which facilitates absorbing ultraviolet (UV) radiation. Sunscreens are formulated to protect human skin from the redox activity of the TiO2 nanoparticles (NPs) and are mass-marketed as safe for people and the environment. By closely examining the biological use of TiO2 and the influence of biomolecules on its stability and solubility, we reassess the reactivity of the material in the presence and absence of UV energy. We also consider the alarming impact that TiO2 NP seepage into bodies of water can cause to the environment and aquatic life, and the effect that it can have on human skin and health, in general, especially if it penetrates into the human body and the bloodstream.