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.

Materials based on natural high molecular compounds are particularly interesting for biomedical applications. It is known that the cross-linking agent used for preparation of biomacromolecule-based materials is as important as used biopolymer. Therefore, natural cross-linkers containing reactive carbonyl groups are of great interest especially for modifying properties of natural polysaccharides. One of the most popular cross-linking agents is glutaraldehyde. Nevertheless, the unreacted particles can be released from the cross-linked material and cause cytotoxic effects. This can be eliminated when using a cross-linker based e.g., on polysaccharides. This article describes quick and efficient synthesis of dialdehyde chitosan (DACS) and its application for the preparation of chitosan films. Materials obtained with different amount of DACS were fully characterized in terms of structure and surface morphology. Thermal and mechanical properties as well as hydrophilic character were also examined. The results obtained were compared with the materials obtained by cross-linking chitosan with low molecular weight glutaraldehyde and high molecular weight cross-linking agent based on polysaccharide–dialdehyde starch. Toxicity of all obtained materials was tested using the Microtox® test. It has been shown that due to better mechanical, thermal and surface properties as well as lower toxicity, dialdehyde chitosan is a very promising crosslinking agent.

Phototherapies, including photodynamic therapy (PDT), have been widely used in the treatment of various diseases, especially for cancer. However, there is still a lack of effective, safe photosensitizers that would be well tolerated by patients. The combination of several methods (like phototherapy and hyperthermia) constitutes a modern therapeutic approach, which demands new materials based on components that are non-toxic without irradiation. Therefore, this study presents the synthesis and properties of novel, advanced nanomaterials in which the advantage features of the magnetic nanoparticles and photoactive compounds were combined. The primary purpose of this work was the synthesis of magnetic nanoparticles coated with biocompatible and antitumor polysaccharide-levan, previously unknown from scientific literature, and the deposition of potent photosensitizerzinc(II) phthalocyanine on their surface. In order to better characterize the nature of the coating covering the magnetic core, the atomic force microscope analysis, a contact angle measurement, and the mechanical properties of pure levan and its blend with zinc(II) phthalocyanine films were investigated. This magnetic nanomaterial revealed the ability to generate singlet oxygen upon exposure to light. Finally, preliminary toxicity of obtained nanoparticles was tested using the Microtox® testwith and without irradiation.

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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.

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Superficial and systemic fungal infections are essential problems for the modern health care system. One of the challenges is the growing resistance of fungi to classic antifungals and the constantly increasing cost of therapy. These factors force the scientific world to intensify the search for alternative and more effective methods of treatment. This paper presents an overview of new fungal inactivation methods using Photodynamic Antimicrobial Chemotherapy (PACT). The results of research on compounds from the groups of phenothiazines, xanthanes, porphyrins, chlorins, porphyrazines, and phthalocyanines are presented. An intensive search for a photosensitizer with excellent properties is currently underway. The formulation based on the existing ones is also developed by combining them with nanoparticles and common antifungal therapy. Numerous studies indicate that fungi do not form any specific defense mechanism against PACT, which deems it a promising therapeutic alternative.