Metallic and metal oxide nanoparticles (NPs), including titanium dioxide NPs, among polymeric NPs, liposomes, micelles, quantum dots, dendrimers, or fullerenes, are becoming more and more important due to their potential use in novel medical therapies. Titanium dioxide (titanium(IV) oxide, titania, TiO₂) is an inorganic compound that owes its recent rise in scientific interest to photoactivity. After the illumination in aqueous media with UV light, TiO₂ produces an array of reactive oxygen species (ROS). The capability to produce ROS and thus induce cell death has found application in the photodynamic therapy (PDT) for the treatment of a wide range of maladies, from psoriasis to cancer. Titanium dioxide NPs were studied as photosensitizing agents in the treatment of malignant tumors as well as in photodynamic inactivation of antibiotic-resistant bacteria. Both TiO₂ NPs themselves, as well as their composites and combinations with other molecules or biomolecules, can be successfully used as photosensitizers in PDT. Moreover, various organic compounds can be grafted on TiO₂ nanoparticles, leading to hybrid materials. These nanostructures can reveal increased light absorption, allowing their further use in targeted therapy in medicine. In order to improve efficient anticancer and antimicrobial therapies, many approaches utilizing titanium dioxide were tested. Results of selected studies presenting the scope of potential uses are discussed in this review.

Titanium dioxide (TiO₂) is a material of diverse applications commonly used as a food additive or cosmetic ingredient. Its prevalence in products of everyday use, especially in nanosize, raises concerns about safety. Current findings on the safety of titanium dioxide nanoparticles (TiO₂ NPs) used as a food additive or a sunscreen compound are reviewed and systematized in this publication. Although some studies state that TiO₂ NPs are not harmful to humans through ingestion or via dermal exposure, there is a considerable number of data that demonstrated their toxic effects in animal models. The final agreement on the safety of this nanomaterial has not yet been reached among researchers. There is also a lack of official, standardized guidelines for thorough characterization of TiO₂ NPs in food and cosmetic products, provided by international authorities. Recent advances in the application of ‘green-synthesized’ TiO₂ NPs, as well as comparative studies of the properties of ‘biogenic’ and ‘traditional’ nanoparticles, are presented. To conclude, perspectives and directions for further studies on the toxicity of TiO₂ NPs are proposed.

Contamination of the environment has been a growing problem in recent years. Due to the rapid growth in human population, the expansion of cities, along with the development of industry, more and more dangerous chemicals end up in the environment, especially in soil and water. For the most part, it is not possible to effectively remove chemicals through traditional remediation techniques, because those used in treatment plants are not specifically designed for this purpose. Therefore, new approaches for water remediation are in great demand. Many efforts have been focused on applications of photocatalysis for the remediation of chemical pollutants including drugs. Titanium(IV) oxide nanoparticles have particularly been considered as potential photocatalysts due to their favorable properties. In this article, we present the problem of emerging contaminants including drugs and discuss the use of photocatalysts based on titanium(IV) oxide nanoparticles for their degradation. A wide selection of materials, starting from bare TiO₂, via its hybrid and composite materials, are discussed including those based on carbonaceous materials or connections with macrocyclic structures. Examples of photodegradation experiments on TiO₂-based materials including those performed with various active pharmaceutical ingredients are also included.

The renin-angiotensin system has been established as an attractive target for pharmacological intervention since the discovery of first angiotensin-converting enzyme inhibitors (ACE-Is). In fact, these drugs are primarily used in the management of cardiovascular system-related diseases and renal insufficiency. Their mechanism of action involves the adjustment of balance between vasoconstrictive, hypertrophic and salt/water-retentive angiotensin II and vasodilatory and natriuretic bradykinin by the inhibition of angiotensin II biosynthesis and bradykinin degradation. Currently there are thirteen family members approved for use in humans. They differ in structure, chemistry and pharmacokinetic and pharmacodynamic properties yet they display a similar pharmacologic and toxicologic profile. All of them are effective in the treatment of hypertension as well as in cardiac insufficiency or diabetic nephropathy. Although they are generally well-tolerated several serious side-effects including life-threatening angioedema, renal failure and persistent dry cough could occur during the administration of ACE-Is, which may require the cessation of therapy. Furthermore, to provide maximum safety and efficiency of ACE-Is-based therapy, the knowledge of the related drug interactions and chronokinetics seems to be an absolute requirement. Here we discuss the above-mentioned issues regarding the pharmaceutical and chemical properties of the commercially- used ACE-Is.