Spider silk is a natural material possessing unique properties such as biocompatibility, regenerative and antimicrobial activity, and biodegradability. It is broadly considered an attractive matrix for tissue regeneration applications. Optical monitoring and potential control over tissue regrowth are attractive tools for monitoring of this process. In this work, we show upconversion modification of natural spider silk fibers with inorganic nanoparticles. To achieve upconversion, metal oxide nanoparticles were doped with low concentrations of rare-earth elements, producing potentially biocompatible luminescent nanomaterials. The suggested approach to spider silk modification is efficient and easy to perform, opening up sensing and imaging possibilities of biomaterials in a noninvasive and real-time manner in bio-integration approaches.

Nanostructured drugs are being approved for clinical use, although there is a serious deficit of systematic studies of these materials. Data on toxicity of nanoparticles (NPs) can vary due to different methods of preparation, size, and shape. We investigated the toxicity against cultured human cells, the acute toxicity in mice, and the influence on conjugative transfer of antibiotic resistance genes of clinically relevant NPs such as TiO2, ZrO2, HfO2, Ta2O5, Fe3O4, and AlOOH. NPs were synthesized as aqueous sols by the same method in aqueous solution, with almost identical size 2–10 nm. None of these NPs was cytotoxic at concentrations compatible with water solubility. Furthermore, TiO2, HfO2, Ta2O5, Fe3O4, and AlOOH were not toxic to mice after oral administration. However, ZrO2 showed rather high toxicity, with LD50 2277.8 mg/kg. Experiments with plasmid transfer between bacteria demonstrated that AlOOH NPs were the most hazardous since this material promoted the emergence of resistance to antibiotics. Thus, although our metal oxide NPs are largely non-toxic, their properties may differ in specific biological situations.

We report here a new feasible approach to produce upconversion luminescent metal oxide aerogels with high textural characteristics. Monolithic aerogels show upconversion luminescence converting near-infra red excitation into visible light emission.

High-performance functional biomaterials are becoming increasingly requested. Numerous natural and artificial polymers have already demonstrated their ability to serve as a basis for bio-composites. Spider silk offers a unique combination of desirable aspects such as biocompatibility, extraordinary mechanical properties, and tunable biodegradability, which are superior to those of most natural and engineered materials. Modifying spider silk with various inorganic nanomaterials with specific properties has led to the development of the hybrid materials with improved functionality. The purpose of using these inorganic nanomaterials is primarily due to their chemical nature, enhanced by large surface areas and quantum size phenomena. Functional properties of nanoparticles can be implemented to macro-scale components to produce silk-based hybrid materials, while spider silk fibers can serve as a matrix to combine the benefits of the functional components. Therefore, it is not surprising that hybrid materials based on spider silk and inorganic nanomaterials are considered extremely promising for potentially attractive applications in various fields, from optics and photonics to tissue regeneration. This review summarizes and discusses evidence of the use of various kinds of inorganic compounds in spider silk modification intended for a multitude of applications. It also provides an insight into approaches for obtaining hybrid silk-based materials via 3D printing.

The development of the physicochemical basis for applications of nanoradiosensitizers for targeted treatment of tumors is one of the crucial issues of modern radiotherapy. Ceramic nanoparticles (NPs) composed of heavy metal oxides are considered as prospective sensitizers, particularly for X-ray treatment. This study reports a novel approach for experimental simulations of the radiosensitizing effect of NPs in biomimetic systems based on the quantification of radicals produced from organic components in concentrated aqueous organic solutions using the spin-trapping technique with electron paramagnetic resonance detection. This approach was first applied to X-ray irradiation (45 kVp) of aqueous methanol solutions systems containing different concentrations of hafnium oxide nanoparticles with an average diameter of ca. 84 nm (up to 1.8 wp). It was found that the amount of radicals produced from methanol at the same exposition time increased linearly with the increasing content of HfO 2 NPs. The effect can be reasonably explained by the physical enhancement mechanism associated with efficient transfer of absorbed energy from the NPs to aqueous organic medium. The Monte Carlo simulations were applied to calculate the absorbed dose in the studied systems as a function of NP concentration. The experimental enhancement factor in the formation of radicals (0.71 wp −1 ) was found to be slightly lower than the calculated coefficient of the absorbed dose enhancement (0.80 wp −1 ), which can be explained by partial self-absorption of generated secondary electrons inside rather bulky HfO 2 nanoparticles. The proposed model approach may provide a rational ground for comparative studies of different nanoradiosensitizers and the optimization of the NP size, photon energy, and other factors.