Martina Miloloža

Environmental concerns with petroleum-based polymers have accelerated the development of biodegradable alternatives, making poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) a promising candidate for sustainable packaging. However, its functional performance necessitates modification through blending. In this study, blends containing 65–85 wt.% polylactide (PLA) were investigated to establish structure–property relationships relevant to compostable packaging. The results reveal partial miscibility of the blends and pronouncedcomposition-dependent changes in morphology and thermal behavior, characterized by an increase in glass transition temperature and a decrease in PLA melting temperature. Increasing PLA content (≥80 wt.%) enhanced thermal stability, increasing the degradation temperature to 288.0 °C. In contrast, higher PHBV content (≥25 wt.%) significantly improved barrier properties of PLA, reducing oxygen and water vapor transmission rates to 74.47 cm³ m⁻² day⁻¹ and 29.11 g m⁻² day⁻¹, respectively. Biodegradation behavior revealed complete degradation of PHBV after 56 days, whereas PLA showed only 1.29% mass loss under identical conditions. In the blends, biodegradation proceeded preferentially through the PHBV phase, resulting in composition-dependent mass loss. Among the investigated compositions, PLA65/PHBV provided the most balanced combination of barrier performance, mechanical behavior, and biodegradation response. Overall, these findings demonstrate that tailoring composition enables the design of polymer systems for sustainable packaging applications.

Antiviral substances are considered emerging contaminants. Once released into the environment, they may affect organisms through complex and often still-unknown mechanisms. This study focuses on a class of antiviral substances with potential use in treating COVID-19 patients, aiming to identify specific structural characteristics that significantly contribute to their ecotoxicity. An empirical approach called quantitative structure–activity relationship (QSAR) was used for this purpose. The study examined 13 antiviral substances: atazanavir, daclatasvir, darunavir, emtricitabine, favipiravir, lopinavir, nirmatrelvir, oseltamivir, remdesivir, ribavirin, ritonavir, and sofosbuvir. The ecotoxicity of these antivirals was assessed using three tests: the Aliivibrio fischeri test, the Chlorella sp. test, and the Pseudomonas putida test. These three microorganisms represent different trophic levels in aquatic and soil ecosystems. Ecotoxicity was expressed as EC₂₀ and EC₅₀, and these values served as the dependent variables in the QSAR models. A large set of numerical descriptors calculated from the molecular structures of the antivirals was used as an independent variable. EC₂₀-based QSAR models offer insight into the effects of antivirals under sub-lethal exposure conditions. The results indicated that sub-lethal exposure in Aliivibrio fischeri was associated with favorable electronic properties and compact structures that promote cellular accumulation, while long-range fragments reduced toxicity. In Chlorella sp., sub-lethal exposure was driven by optimal molecular size, chain length, and specific electronic groups enabling cell penetration and biochemical inhibition. For sub-lethal exposure in P. putida, lipophilicity and reactive group geometry enhanced toxicity, while high short-range polarity mitigated it by limiting membrane permeability. Acute toxicity patterns showed similar trade-offs: strong electronic reactivity increased potency, but steric bulk, long-range polarity, or unfavorable mass distribution frequently restricted bioavailability and reduced toxic effects. Overall, the models demonstrated that antiviral toxicity results from a balance of electronic activity, structural accessibility, and physicochemical constraints, providing a mechanistic basis for predicting the environmental risk of selected antiviral substances.

One of the main challenges facing the pharmaceutical industry today is the low solubility of active pharmaceutical ingredients (APIs), which leads to low bioavailability, reduced therapeutic efficacy, and the need for higher drug doses. Eutectic solvents (ES) offer a promising solution by effectively dissolving APIs, creating API-ES systems that can significantly improve drug solubility and delivery. In this study, three distinct ESs were prepared by combining various components, with their successful formation confirmed through Fourier Transform Infrared Spectroscopy. Key physicochemical properties, including the density, viscosity, and pH of the prepared solvents, were subsequently determined. Ceritinib (CRT), an API utilized in the treatment of non-small cell lung cancer, was then incorporated into the prepared ESs to yield the API-ES systems. A comparative analysis was conducted to assess the release profiles of pure CRT versus CRT within the API-ES systems. Furthermore, the permeability and diffusion coefficient of the drug within these systems were also determined. The results conclusively demonstrated that the formation of the API-ES system increased the solubility of CRT in water. This achievement represents a vital initial step toward optimizing the delivery of this drug and highlights the significant potential for developing a novel, improved pharmaceutical formulation.

The extensive use of antiviral substances (SASs) during and after the COVID-19 pandemic has increased their release into wastewater systems, raising concerns regarding their persistence and potential ecotoxicological effects. The primary objective of this study was to isolate bacterial strains from activated sludge (AS) that possess the ability to biodegrade SASs. From the AS sample, three bacterial species, Comamonas testosteroni (I2), Bacillus amyloliquefaciens (I3) and Bacillus mycoides (I4), were successfully isolated and identified. These strains were subsequently applied in biodegradation experiments targeting seven SASs: daclatasvir (DCV), darunavir (DRV), favipiravir (FAV), lopinavir (LOP), remdesivir (REM), ritonavir (RIT), and umifenovir (UMI). During the experiments, residual SAS concentrations, microbial growth parameters, physicochemical indicators and ecotoxicity were monitored. All three strains demonstrated substantial biodegradation potential, achieving reductions exceeding 90% for most tested compounds, with particularly low toxicity observed in experiments conducted with AS and Bacillus amyloliquefaciens. These findings highlight the relevance of AS-derived bacteria as promising candidates for enhancing SAS removal in wastewater treatment processes.

Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) is a biodegradable polyester considered for food packaging, though its mechanical and barrier limitations pose challenges. This study assessed PHBV/TiO₂ nanocomposites for packaging applications. Differential scanning calorimetry revealed reduced crystallinity and lower melting points with an increase in TiO₂ content. Thermal stability improved at 1% and 3% TiO₂, raising onset temperatures to 283 °C and 284 °C, respectively. Scanning electron microscopy and FTIR confirmed uniform nanoparticle dispersion without agglomeration. Tensile tests showed decreasing strength and modulus from 1% to 7% TiO₂, with peak elongation at 3%, whereas viscosity behavior declined with higher nanoparticle loading. Low portions of nanoparticles (1% and 3%) induced the improvement in barrier properties against oxygen and water vapor. The highest biodegradation rate occurred at 7% TiO₂. Overall, the nanocomposites’ properties tend to deteriorate with the addition of higher portions of TiO₂. Thus, despite some improvements, the nanocomposites did not deliver consistent, multi-property enhancements to justify use in food packaging. Key metrics like sealability and appearance were not evaluated. Future research should explore surface-treated TiO₂, alternative fillers, compatibilizers, and optimized processing, alongside standardized safety assessments for food-contact applications.

Svakodnevno smo izloženi raznovrsnim kemijskim spojevima prisutnim u hrani, kozmetici, proizvodima za kućanstvo i okolini. Proizvodi za čišćenje, poput sapuna i deterdženata, često sadrže tvari koje se proizvode u velikim količinama. Njihova nepravilna uporaba može predstavljati rizike za zdravlje i okoliš. Česti kemijski sastojci u takvim proizvodima su amonijak, hlapljivi organski spojevi, kvaterni amonijevi spojevi, hipoklorit i izotiazolni ioni. Njihova upotreba može rezultirati raznim zdravstvenim tegobama, poput astme, iritacije kože i očiju te glavobolja. Tijekom pandemije COVID-19 primijećena je povećana upotreba dezinfekcijskih sredstava, što je dodatno povećalo izloženost tim kemijskim spojevima. One dospijevaju u okoliš kroz otpadne vode i isparavanjem, utječući na ekosustave. Istraživanja su pokazala toksični utjecaj tih tvari na testne organizme poput morske bakterije Vibrio fischeri i vodenbuhe Daphnia magna. Zbog toga su uvedene regulacije i politike za smanjenje njihove koncentracije te se istražuju alternative s manje toksičnim sastojcima. U radu će biti objašnjen sastav kemikalija u sredstvima za čišćenje, njihov utjecaj na ljude, organizme i okoliš te alternative koje se istražuju.

Wastewater from various industries, such as coking, mining, pharmaceutical, petroleum, etc., often contains high concentrations of cyanides, thiocyanates, and phenolic compounds, individually or in combination, making them serious sources of pollution for natural watercourses. Protecting water bodies and preserving life within them requires reducing the concentrations of these compounds to legally prescribed levels. Given the complexity of such wastewater effective treatment generally involves multiple technologies, with biological treatment being both indispensable and highly effective. Therefore, exploring the potential for biological degradation of these compounds, along with the mechanisms influencing their degradation under various environmental conditions, is crucial. This paper provides an overview of the biological degradation of toxic compounds in industrial wastewater, investigating various microorganisms and degradation techniques to ensure effective and environmentally friendly water treatment.

Although the coking industry is a major polluter, it is still an important and irreplaceable industry in many countries. Wastewater from the coking industry typically contains large amounts of various hazardous substances, including phenols, cyanides, and thiocyanates; we conducted a comprehensive study on their ecotoxicity. This included five different toxicity tests with common species from different trophic levels: the bacteria Aliivibrio fischeri and Pseudomonas putida, the microalgae Chlorella sp., the duckweed Lemna minor, and the onion plant Allium cepa. These tests have rarely or never been used for these three toxicants. The results show that cyanide generally has the highest toxicity, while phenol has a relatively equal or higher toxicity than thiocyanate, depending on the test. Since no data on the joint toxic action of these three toxicants can be found in the literature, and although their joint occurrence in the aquatic environment is very likely, we performed joint toxic action analysis. The analysis was performed for binary and ternary mixtures of the toxicants using the Aliivibrio fischeri test. The concentration addition model was used as a reference model for the toxic behavior of these mixtures. The results obtained showed a synergistic deviation from the concentration addition model for combinations of phenol with cyanide and with thiocyanate, while the combination of cyanide and thiocyanate led to additive toxic behavior.

Tekstilna industrija ima značajan utjecaj na okoliš, a vlakna poput poliestera, pamuka i razni procesi obrade tih vlakana osnova su onečišćenja. Poliester, kao najčešće tekstilno vlakno, negativno utječe na okoliš zbog svojstva nerazgradivosti i uporabe fosilnih goriva, tj. nafte, za njegovu proizvodnju. Pamuk ima izvanredna svojstva, ali njegov uzgoj često uključuje uporabu gnojiva i pesticida, koji onečišćuju vode i tlo. Obrada tekstila, osobito mokra obrada, zahtijeva velike količine vode i energije te generira znatne količine otpadnih voda bogatih kemikalijama i bojilima. Takav otpadni tok, ako je neobrađen, znatno onečišćuje vodu i tlo. Također, vlakna mikroplastike iz tekstila, posebice iz pranja odjeće, predstavljaju sve veći problem s ozbiljnim posljedicama za vodeni ekosustav. Uporaba deterdženata dodatno komplicira situaciju, pridonoseći eutrofikaciji i ekotoksičnosti voda. Brza moda s kratkim životnim ciklusom odjeće generira velike količine tekstilnog otpada, što dodatno opterećuje okoliš. S druge strane, javlja se spora moda kao alternativa, a usredotočuje se na proizvodnju manjih količina tekstilnih proizvoda više kvalitete. Tekstilna industrija zahtijeva strože regulacije i održive prakse da bi smanjila svoj negativan utjecaj na okoliš. Rješavanje tih problema zahtijeva integrirani pristup koji uključuje smanjenje potrošnje resursa, poboljšanje obrade otpadnih voda, promicanje održivih materijala i proizvodnih procesa te educiranje potrošača o utjecaju njihovih odluka na okoliš. Prema tome, uvedene su i mnoge regulative s ciljem promicanja održivog i kružnog gospodarenja tekstilnom otpadom.