High-Entropy Layered Rare Earth Hydroxides.

New high-entropy layered rare earth hydroxides ─ (Y,Eu,Gd,Er,Sm)2(OH)5NO3, (Y,Eu,Gd,Er,Tb)2(OH)5NO3, (Y,Eu,Gd,Er,Yb)2(OH)5NO3, (Y,Eu,Gd,Er,Nd)2(OH)5NO3, and (Y,Eu,Gd,Er,Nd,Sm,Tb)2(OH)5NO3 ─ were obtained using a hydrothermal microwave method. The annealing of layered rare earth hydroxides at 900 °C resulted in the corresponding high-entropy rare earth oxides. Based on inductively coupled plasma atomic emission spectroscopy data, the values for configurational entropy for both rare earth hydroxides and oxides were estimated, confirming the formation of high-entropy compounds. Energy-dispersive X-ray spectroscopy mapping, including mapping in the scanning transmission microscopy mode, showed no signs of chemical segregation and confirmed uniform rare earth elements' distribution both in the particles of high-entropy layered basic nitrates and in the particles of high-entropy oxides. The ratios of rare earth cations in the initial aqueous solutions of mixed nitrates were close to the ratios of cations in the resulting high-entropy layered rare earth basic nitrates and high-entropy rare earth oxides.

Synthesis of SrF2:Yb:Er ceramic precursor powder by co-precipitation from aqueous solution with different fluorinating media: NaF, KF and NH4F.

The major challenge in optical ceramic technology is the quality of the starting precursor powder for pressing, which is a key element in the optical ceramic industry. One express and helpful technique for the estimation of powder quality is the estimation of the quantum yield of up-conversion luminescence; therefore precursor powders must exhibit high values of up-conversion luminescence efficiency. Single-phase solid solutions based on strontium fluoride doped with ytterbium and erbium were synthesised by co-precipitation from aqueous solutions using sodium fluoride, potassium fluoride and ammonium fluoride as fluorinating agents. The asymmetry of X-ray diffraction maxima indicated the presence of two populations of particles with the same chemical composition. The processes of extended flat particles' growth from smaller particles with a spherical morphology were revealed with transmission electron microscopy and X-ray diffraction. It was shown that when sodium fluoride and potassium fluoride were used they entered the crystal structure in an amount of 3-4 mol% and 1 mol%, respectively. The introduction of sodium and potassium led to an improvement in the sintering ability of particles and a significant increase in the particle size in ceramics by a factor of 5 and 2, respectively, in comparison with the use of ammonium fluoride. The quantum yield values of up-conversion luminescence at the level of tenths of a percent at a low pump power density of 0.1 W cm-2 were very high, which suggests that these synthetic techniques can be considered to be promising for the preparation of precursors of laser ceramics.

Amorphous and crystalline cerium(IV) phosphates: biocompatible ROS-scavenging sunscreens.

This paper reports on a comprehensive study of the UV-shielding properties (namely, the sun protection factor and the factor of protection against UV-A radiation) and cytotoxicity (including photocytotoxicity) of amorphous and crystalline cerium(IV) phosphates. It has been shown that cerium(IV) phosphate NH4Ce2(PO4)3 is characterised by UV-shielding properties that are comparable to those of nanocrystalline TiO2 and CeO2. Moreover, cerium(IV) phosphates did not show toxicity towards cell cultures of NCTC L929 line mouse fibroblasts and human mesenchymal stem cells, in a wide range of concentrations, and even enhanced the proliferative activity of the latter. In a model study of the photoprotective properties of cerium(IV) phosphates on human mesenchymal stem cells, the pronounced protective effect of NH4Ce2(PO4)3 was observed, which was comparable to the shielding action of nanocrystalline CeO2. The results have shown that tetravalent cerium phosphates can be considered as promising UV-filters for sunscreen applications.

Assessment of Radiological Hazard of Radioactive Waste Using Effective or Organ Doses: How This May Affect Final Waste Disposal.

ABSTRACT: The radiological hazard of spent nuclear fuel and radioactive waste slows down further development of nuclear energy systems. The authors evaluate timescales required to reduce the radiological hazard of accumulated waste to the reference level of natural uranium that had been consumed by the nuclear energy system. The estimate of this time scale depends on the radiological hazard metric used in the calculations. In this study, two metrics are compared: (1) the committed effective dose based on ICRP Publication 72 and (2) the lifetime radiation risk calculated with use of organ doses and recent radiation risk models recommended by ICRP. The effective dose of the waste reaches the reference level 300 y after the accumulation of waste, while lifetime attributable risk of waste converges to natural uranium in 100 y. Thus, the lifetime attributable risk (LAR) metric is more appropriate to estimate the time requirements for radioactive waste storage and disposal. The effective dose metric significantly overestimates this timescale as it is not intended for quantifying radiation-related risks.

Biocompatible dextran-coated gadolinium-doped cerium oxide nanoparticles as MRI contrast agents with high T1 relaxivity and selective cytotoxicity to cancer cells.

Gd-based complexes are widely used as magnetic resonance imaging (MRI) contrast agents. The safety of previously approved contrast agents is questionable and is being re-assessed. The main causes of concern are possible gadolinium deposition in the brain and the development of systemic nephrogenic fibrosis after repeated use of MRI contrasts. Thus, there is an urgent need to develop a new generation of MRI contrasts that are safe and that have high selectivity in tissue accumulation with improved local contrast. Here, we report on a new type of theranostic MRI contrast, namely dextran stabilised, gadolinium doped cerium dioxide nanoparticles. These ultra-small (4-6 nm) Ce0.9Gd0.1O1.95 nanoparticles have been shown to possess excellent colloidal stability and high r1-relaxivity (3.6 mM-1 s-1). They are effectively internalised by human normal and cancer cells and demonstrate dose-dependent selective cytotoxicity to cancer cells.

Evaluation of Migration Radiological Equivalence for Dual Component Nuclear Waste in a Deep Geological Repository.

ABSTRACT: The paper is concerned with the issue of achieving the radiological equivalence (the equivalence of radiation risks) of radioactive waste of nuclear reactors and corresponding mass of natural uranium, taking into account the different migration ability of radionuclides in geological formations and soil. This migration radiological equivalence is being investigated for the deep burial of radioactive waste in the case of the development of a two-component nuclear power system with the concurrent use of thermal neutron reactors and fast neutron reactors. Calculations were performed of radiation doses and radiation risks of cancer death arising from consumption of drinking water from a well above a disposal site. The radiation risk relating to a two-component nuclear power system is lower than that from natural uranium; i.e., after reaching the radiological equivalence (100 y of storage) over the timescale of 109 y, the principle of migration radiological equivalence is satisfied. It would take 106 y after radioactive waste disposal to reach the migration radiological equivalence if only thermal reactors were operated. As regards consumption of well drinking water, the radiation risk does not exceed 10-5 y-1 for a two-component nuclear power system, while being 10-3 y-1 (socially unacceptable level) for a power system using only thermal reactors. Radionuclides 241Am, 239Pu, and 240Pu in drinking water make the main contribution to the doses and radiation risks of people for 104 y after the disposal of radioactive waste.

The first amorphous and crystalline yttrium lactate: synthesis and structural features.

The synthesis and crystal structure of the first molecular yttrium lactate complex, Y(Lac)3(H2O)2, is reported, where the coordination sphere of yttrium is saturated with lactate ligands and water molecules, resulting in a neutral moiety. In Y(Lac)3(H2O)2, hydrogen bonding between α-hydroxy groups and water molecules allows for the formation of 2D layers. A subtle variation in synthetic conditions, i.e. a slight increase in pH (5.5 instead of 4.5) promoted the formation of a semi-amorphous fibrous material with a presumed chemical composition of Y4(OH)5(C3H5O3)7·6H2O. The flattened fibres in this material are responsible for its good flexibility and foldability.

Ceria-Containing Hybrid Multilayered Microcapsules for Enhanced Cellular Internalisation with High Radioprotection Efficiency.

Cerium oxide nanoparticles (nanoceria) are believed to be the most versatile nanozyme, showing great promise for biomedical applications. At the same time, the controlled intracellular delivery of nanoceria remains an unresolved problem. Here, we have demonstrated the radioprotective effect of polyelectrolyte microcapsules modified with cerium oxide nanoparticles, which provide controlled loading and intracellular release. The optimal (both safe and uptake efficient) concentrations of ceria-containing microcapsules for human mesenchymal stem cells range from 1:10 to 1:20 cell-to-capsules ratio. We have revealed the molecular mechanisms of nanoceria radioprotective action on mesenchymal stem cells by assessing the level of intracellular reactive oxygen species (ROS), as well as by a detailed 96-genes expression analysis, featuring genes responsible for oxidative stress, mitochondrial metabolism, apoptosis, inflammation etc. Hybrid ceria-containing microcapsules have been shown to provide an indirect genoprotective effect, reducing the number of cytogenetic damages in irradiated cells. These findings give new insight into cerium oxide nanoparticles' protective action for living beings against ionising radiation.

Nanoceria-curcumin conjugate: Synthesis and selective cytotoxicity against cancer cells under oxidative stress conditions.

A water- and alcohol-soluble cerium oxide-curcumin conjugate was obtained by co-evaporation with poly(N-vinylpyrrolidone) (PVP). A nanocomposite consisting of hybrid organic-inorganic particles was stable in a wide range of pH values. Its properties were evaluated using nine cell lines: normal (MDBK, ST, Vero) and malignant (L929, T98G, HEp-2, A549, RIN-m5F, Hep G2). PVP-stabilised nanoceria was shown to inhibit autoxidation of curcumin, to enhance curcumin photostability, to promote bioaccumulation and to affect curcumin cytotoxicity and photocytotoxicity, depending on cell type, being more toxic to cancer cells in a selective manner. Under the conditions of UVA/UVC or H2O2-induced oxidative stress, the nanoceria-PVP-curcumin (NPC) conjugate was found to possess a selective cytotoxicity: it caused drastic inhibition of metabolic activity or a decrease in the total number of tumour cells, while in non-transformed cultures under the same conditions, the nanoceria-PVP-curcumin conjugate protected cells from these damaging factors. The NPC-conjugate, unlike curcumin itself, demonstrated a photosensitising effect in tumour cell cultures, while protecting non-transformed cultures from the damaging effects of UV radiation or oxidative stress. Based on the results obtained, we strongly believe that this novel hybrid material has enhanced characteristics compared to other curcumin formulations, and can be considered as a potent drug for biomedical applications, including cancer therapy.

Relationship between follow-up periods and the low-dose ranges with statistically significant radiation-induced risk of all solid cancers in the Russian cohort of Chernobyl emergency workers.

Radiation-induced risks for all solid cancer incidence and mortality were studied in the cohort of Russian Chernobyl emergency workers. The cohort included 69,440 persons with documented individual radiation dose accrued over the time of working in the Chernobyl zone. The mean age at entry into the zone of recovery operations was 33.9 years and accumulated radiation dose was 132.9 mGy. A total of 6981 solid cancer incident cases and 4272 deaths occurred in this cohort from 1992 to 2017. Three follow-up periods were studied: 1992-2009, 1992-2013, and 1992-2017. For each follow-up period, the lowest dose range with statistically significant (p < 0.05) radiation-induced risk of all solid cancer incidence and mortality were obtained. For the incidence of all solid cancer during the follow-up period 1992-2009, this lowest dose range was estimated to be 0-250 mGy with an excess relative risk per dose of ERR Gy-1 = 0.51 and 95% confidence interval (CI) (0.02; 1.05) Gy-1. For the period 1992-2013, the lowest dose range was 0-175 mGy with ERR Gy-1 = 0.85 (95% CI 0.03; 1.78), while for the whole follow-up period 1992-2017, it was 0-175 mGy with ERR Gy-1 = 0.81 (95% CI 0.08; 1.62). For mortality from all solid cancers during the follow-up period 1992-2009, the lowest dose range with statistically significant radiation-induced risk was estimated to be 0-225 mGy with ERR Gy-1 = 1.07 (95% CI 0.31; 0.97). For the period 1992-2013, the lowest dose range was 0-225 mGy with ERR Gy-1 = 0.86 (95% CI 0.23; 1.58), while for the whole follow-up period 1992-2017, the lowest dose range was 0-200 mGy with ERR Gy-1 = 0.82 (95% CI 0.10; 1.65). Thus, it was found that the minimal level of significant exposure (Dmin), for which a statistically significant radiation-induced risk of all solid cancers was obtained for Russian emergency workers (with individual doses of 0 - Dmin), decreases with increasing duration of cohort observation, both for cancer incidence and mortality.

Opposite effects of low intensity light of different wavelengths on the planarian regeneration rate.

Planarian freshwater flatworms have the unique ability to regenerate due to stem cell activity. The process of regeneration is extremely sensitive to various factors, including light radiation. Here, the effect of low-intensity LED light of different wavelengths on regeneration, stem cell proliferation and gene expression associated with these processes was studied. LED matrices with different wavelengths (red (λmax = 635 nm), green (λmax = 520 nm) and blue (λmax = 463 nm), as well as LED laser diodes (red (λmax = 638.5 nm), green (λmax = 533 nm) and blue (λmax = 420 nm), were used in the experiments. Computer-assisted morphometry, whole-mount immunocytochemical study and RT-PCR were used to analyze the biological effects of LED light exposure on the planarian regeneration in vivo. It was found that a one-time exposure of regenerating planarians with low-intensity red light diodes stimulated head blastema growth in a dose-dependent manner (up to 40%). The green light exposure of planarians resulted in the opposite effect, showing a reduced head blastema growth rate by up to 21%. The blue light exposure did not lead to any changes in the rate of head blastema growth. The maximum effects of light exposure were observed at a dose of 175.2 mJ/cm2. No significant differences were revealed in the dynamics of neoblasts' (planarian stem cells) proliferation under red and green light exposure. However, the RT-PCR gene expression analysis of 46 wound-induced genes revealed their up-regulation upon red LED light exposure, and down-regulation upon green light exposure. Thus, we have demonstrated that the planarian regeneration process is rather sensitive to the effects of low-intensity light radiation of certain wavelengths, the biological activity of red and green light being dictated by the different expression of the genes regulating transcriptional activity.

CLINICAL AND DOSIMETRIC INFORMATION TO SUPPORT LONG-TERM COHORT STUDY OF CHERNOBYL CLEAN-UP WORKERS IN RUSSIA.

The article describes the activities of the Russian National Radiation-Epidemiological Registry (NRER) as the unified federal information system for research and management of individual medical and dosimetry data of people exposed to radiation as a result of the Chernobyl accident and other radiological events. The NRER was created for long-term registration of lifetime changes in the health status of the registered people. We present medical and dosimetry data management process, which is carried out in compliance with approved protocols. The scope and content of the information to be collected from external resources are defined in the documents approved by the Russian Ministry of Health. As of 2017 reporting year, the NRER contains medical and dosimetry information on 205 044 clean-up workers of the Chernobyl accident (liquidators), collected during the follow-up period from 1986 to 2016. Using special software for management of data from long-term studies of the Russian cohort of Chernobyl liquidators NRER ensures high quality of radiation-epidemiological information. The results of research activities of the NRER make great contribution to understanding biological and health effects of low-level radiation, molecular mechanisms of the effects, development of actions to early diagnostic of radiation-related diseases to respond to the needs of the affected population while minimizing unnecessary anxiety, improvement of targeting treatments delivery to exposed people at high risk, development of measures to reduce health risks from medical radiological procedures. During the post-Chernobyl period, new methods for estimating radiation doses were developed, some of them can be used for express estimation of radiation dose in the event of radiological emergency.

Photo-induced toxicity of tungsten oxide photochromic nanoparticles.

We synthesised a new type of photochromic tungsten oxide nanoparticles, analysed their photocatalytic activity and carried out a thorough analysis of their effect on prokaryotic and eukaryotic organisms. Ultrasmall hydrated tungsten oxide nanoparticles were prepared by means of hydrothermal treatment of tungstic acid in the presence of polyvinylpyrrolidone as a template, stabiliser and growth regulator. Tungstic acid was synthesised through an ion-exchange method using sodium tungstate solution and a strongly acidic cation exchange resin. Upon illumination, photochromic nanoparticles of WO3 were shown to increase greatly their toxicity against both bacterial (both gram-positive and gram-negative - P. aeruginosa, E. coli and S. aureus) and mammalian cells (primary mouse embryonic fibroblasts); under the same conditions, fungi (C. albicans) were less sensitive to the action of tungsten oxide nanoparticles. UV irradiation of primary mouse fibroblasts in the presence of WO3 nanoparticles demonstrated a time- and dose-dependent toxic effect, the latter leading to a significant decrease in dehydrogenase activity and an increase in the number of dead cells. WO3 nanoparticles were photocatalytically active under both UV light and even diffused daylight filtered through a window glass, leading to indigo carmine organic dye discolouration. The obtained experimental data not only show good prospects for biomedical applications of tungsten trioxide, but also demonstrate the need for clear control of biosafety when it is used in various household materials and appliances.

Unexpected Effects of Activator Molecules' Polarity on the Electroreological Activity of Titanium Dioxide Nanopowders.

Titanium dioxide nanoparticles, obtained using the sol-gel method and modified with organic solvents, such as acetone, acetonitrile, benzene, diethyl ether, dimethyl sulfoxide, toluene, and chloroform, were used as the filler of polydimethylsiloxane-based electrorheological fluids. The effect of electric field strength on the shear stress and yield stress of electrorheological fluids was investigated, as well as the spectra of their dielectric relaxation in the frequency range from 25 to 106 Hz. Modification of titanium dioxide by polar molecules was found to enhance the electrorheological effect, as compared with unmodified TiO2, in accordance with the widely accepted concept of polar molecule dominated electrorheological effect (PM-ER). The most unexpected result of this study was an increase in the electrorheological effect during the application of nonpolar solvents with zero or near-zero dipole moments as the modifiers. It is suggested that nonpolar solvents, besides providing additional polarization effects at the filler particles interface, alter the internal pressure in the gaps between the particles. As a result, the filler particles are attracted to one another, leading to an increase in their aggregation and the formation of a network of bonds between the particles through liquid bridge contacts. Such changes in the electrorheological fluid structure result in a significant increase in the mechanical strength of the structures that arise when an electric field is applied, and an increase in the observed electrorheological effect in comparison with the unmodified titanium dioxide.

Radiation Risk of Cardiovascular Diseases in the Cohort of Russian Emergency Workers of the Chernobyl Accident.

This paper continues a series of publications that analyze the impact of radiation on incidence of circulatory system diseases in the cohort of Russian recovery operation workers (liquidators) and presents the results of the analysis of cardiovascular disease (CVD) incidence. The studied cohort consists of 53,772 liquidators who arrived in the Chernobyl accident zone within the first year after the accident (26 April 1986 to 26 April 1987). The individual doses varied from 0.0001 Gy to 1.42 Gy, and the mean external whole body dose in the cohort was 0.161 Gy. A total of 27,456 cases of CVD were diagnosed during the follow-up period 1986-2012 as a result of annual health examinations. A Poisson regression model was applied to estimate radiation risks and other risk factors associated with CVD. The following factors were identified as risk factors for CVD: the dose, duration of the liquidators' work in the Chernobyl zone, and concomitant diseases (diabetes mellitus, hypertension, overweight, and alcohol dependence). The baseline incidence of CVD is statistically significantly (p < 0.001) associated with all studied concomitant diseases. The incidence of CVD has revealed a statistically significant dose response with the lack of a latent period and with the average ERR Gy = 0.47, 95% CI = 0.31, 0.63, p < 0.001. Radiation risks of CVD statistically significantly (p = 0.01) varied with the duration of liquidators' stay in the Chernobyl zone; for those who stayed in the Chernobyl zone less than 6 wk, ERR/Gy = 0.80, 95% CI = 0.53; 1.08, p < 0.001.

Experimental Study of the Effects of Nanodispersed Ceria on Wound Repair.

We studied the effects of nanodispersed ceria on wound healing in vitro and in vivo. It was found that cerium dioxide stimulated wound healing, which manifested in shrinkage of burn wound area (by 1.5 times) and intensification (by 2.4 times) marginal epithelialization.

[Non-Parametric Analysis of Radiation Risks of Mortality among Chernobyl Clean-Up Workers].

Analysis of the relationship between dose and mortality from cancer and circulation diseases in the cohort of Chernobyl clean-up workers based on the data from the National Radiation and Epidemiological Registry was performed. Medical and dosimetry information on the clean-up workers, males, who got radiation doses from April 26, 1986 to April 26, 1987, which was accumulated from 1992 to 2012, was used for the analysis. The total size of the cohort was 42929 people, 12731 deaths were registered in the cohort, among them 1893 deaths from solid cancers and 5230 deaths were from circulation diseases. An average age of the workers was 39 years in 1992 and the mean dose was 164 mGy. The dose-effect relationship was estimated with the use of non-parametric analysis of survival with regard to concurrence of risks of mortality. The risks were estimated in 6 dose groups of similar size (1-70, 70-130, 130-190, 190-210, 210-230 and.230-1000 mGy). The group "1-70 mGy" was used as control. Estimated dose-effect relationship related to cancers and circulation diseases is described approximately with a linear model, coefficient of determination (the proportion of variability explained by the linear model) for cancers was 23-25% and for circulation diseases - 2-13%. The slope coefficient of the dose-effect relationship normalized to 1 Gy for the ratio of risks for cancers in the linear model was 0.47 (95% CI: -0.77, 1.71), and for circulation diseases it was 0.22 (95% CI: -0.58, 1.02). Risks coefficient (slope coefficient of excess mortality at a dose of 1 Gy) for solid cancers was 1.94 (95% CI: - 3.10, 7.00) x 10(-2) and for circulation diseases it was 0.67 (95% CI: -9.61, 11.00) x 10(-2). 137 deaths from radiation-induced cancers and 47 deaths from circulation diseases were registered during a follow up period.

Radiation-epidemiological Study of Cerebrovascular Diseases in the Cohort of Russian Recovery Operation Workers of the Chernobyl Accident.

The paper presents an analysis of the incidence of cerebrovascular diseases (CeVD) in the cohort of Russian workers involved in recovery tasks after the Chernobyl accident. The studied cohort consists of 53,772 recovery operation workers (liquidators) who arrived in the zone of the Chernobyl accident within the first year after this accident (26 April 1986-26 April 1987). The mean external whole body dose in the cohort was 0.161 Gy, while individual doses varied from 0.0001 Gy to 1.42 Gy. During the follow-up period 1986-2012, a total of 23,264 cases of CeVD were diagnosed as a result of annual health examinations. A Poisson regression model was applied for estimation of radiation risks and for an assessment of other risk factors of CeVD. The following factors were considered as risk factors for CeVD: the dose, duration of the liquidators' work in the Chernobyl zone, and the concomitant diseases (hypertension, ischemic heart disease, atherosclerosis, and diabetes). The baseline incidence of CeVD is statistically significantly (p < 0.001) associated with all studied concomitant diseases. The incidence of CeVD has revealed a statistically significant dose response with the lack of a latent period and with the average ERR/Gy = 0.45, 95% CI: (0.28, 0.62), p < 0.001. Radiation risks of CeVD statistically significantly (p = 0.03) varied with the duration of liquidators' stay in the Chernobyl zone; for those who stayed in the Chernobyl zone less than 6 wk, ERR/Gy = 0.64, 95% CI = (0.38; 0.93), p < 0.001. Among studied concomitant diseases, diabetes mellitus statistically significantly (p = 0.002) increases the radiation risk of CeVD: for liquidators with diagnosed diabetes, ERR/Gy = 1.29.

New nanocomposites for SERS studies of living cells and mitochondria.

A great enhancement in Raman scattering (SERS) from heme-containing submembrane biomolecules inside intact erythrocytes and functional mitochondria is demonstrated for the first time using silver-silica beads prepared using a new method involving aerosol pyrolysis with aqueous diamminesilver(i) hydroxide as a unique source of plasmonic nanoparticles for SiO2 microspheres. The recorded SERS spectra reveal a set of characteristic peaks at 750, 1127, 1170, 1371, 1565, 1585 and 1638 cm-1, resulting from the normal group vibrations of the pyrrole rings, methine bridges and side radicals in the heme molecules. The SERS spectra of functional mitochondria are sensitive to the activity of the mitochondrial electron transport chain, thus making the method a novel label-free approach to monitor the redox state and conformation of cytochromes in their natural cell environment. The developed nanocomposites are highly suitable for the analysis of biological objects due to their robust synthesis and superior spatial and temporal signal reproducibility, which was preserved for a period of at least one year.

Cellulose nanofiber-titania nanocomposites as potential drug delivery systems for dermal applications.

In this work, new efficient drug delivery systems based on cellulose nanofiber-titania nanocomposites grafted with three different types of model drugs such as diclofenac sodium, penicillamine-D and phosphomycin were successfully synthesized and displayed distinctly different controlled long-term release profiles. Three different methods of medicine introduction were used to show that various interactions between TiO2 and drug molecules could be used to control the kinetics of long-term drug release. All synthesis reactions were carried out in aqueous media. The morphology, chemical structure and properties of the obtained materials were characterized by SEM, TEM and AFM microscopy, nanoparticle tracking analysis, X-ray diffraction, and TGA analysis. According to FT-IR and UV-Vis spectroscopy data, the titania binds to cellulose nanofibers via formation of ester bonds and to drug molecules via formation of surface complexes. The drug release kinetics was studied in vitro for diclofenac sodium and penicillamine-D spectrophotometrically and for phosphomycin using a radio-labeling analysis with 33P-marked ATP as a model phosphate-anchored biomolecule. The results demonstrated that the obtained nanocomposites could potentially be applied in transdermal drug delivery for anesthetics, analgesics and antibiotics.