In the present work, hybrid nanobiocomposites based on poly(3-hydroxybutyrate), P3HB, with the use of aromatic linear polyurethane as modifier and organic nanoclay, Cloisite 30B, as a nanofiller were produced. The aromatic linear polyurethane (PU) was synthesized in a reaction of diphenylmethane 4,4'-diisocyanate and polyethylene glycol with a molecular mass of 1000 g/mole. The obtained nanobiocomposites were characterized by the small-angle X-ray scattering technique, scanning electron microscopy, Fourier infrared spectroscopy, thermogravimetry, and differential scanning calorimetry, and moreover, their selected mechanical properties, biodegradability, and cytotoxicity were tested. The effect of the organomodified montmorillonite presence in the biocomposites on their properties was investigated and compared to those of the native P3HB and the P3HB-PU composition. The obtained hybrid nanobiocomposites have an exfoliated structure. The presence and content of Cloisite 30B influence the P3HB-PU composition's properties, and 2 wt.% Cloisite 30B leads to the best improvement in the aforementioned properties. The obtained results indicate that the thermal stability and mechanical properties of P3HB were improved, particularly in terms of increasing the degradation temperature, reducing hardness, and increasing impact strength, which were also confirmed by the morphological analysis of these bionanocomposites. However, the presence of organomodified montmorillonite in the obtained polymer biocomposites decreased their biodegradability slightly. The produced hybrid polymer nanobiocomposites have tailored mechanical and thermal properties and processing conditions for their expected application in the production of biodegradable, short-lived products for agriculture. Moreover, in vitro studies on human skin fibroblasts and keratinocytes showed their satisfactory biocompatibility and low cytotoxicity, which make them safe when in contact with the human body, for instance, in biomedical applications.

• Klíčová slova
• biodegradability, cytotoxicity, mechanical properties, polyester, polyurethane, structure–properties relationship, thermal stability,
• Publikační typ
• časopisecké články MeSH

Cost-effective pretreatment of the highly concentrated and biorefractory coking wastewater to improve biodegradability is of significant importance, while green electrochemical technologies without external chemicals addition are charming but still challenging due to its high energy consumption. In this work, a novel multi-stages flow through peroxi-coagulation (PC) was for the first time developed with graphite felt cathode modified by graphene, showing an excellent performance in removal of 71.5% COD, 72.3% phenol and 59.4% NH3-N and significant biodegradability enhancement with a low energy consumption as 1.2 kWh/m3. Compared with conventional flow PC, this process was more cost-effective due to more intensive .OH production and higher utilization of generated active species. Through UV spectrophotometry and GC-MS analysis, the improvement of biodegradability was attributed to the reduction of both low and high molecular weight compounds content in the coking wastewater. Comparing to the electro-Fenton, electrocoagulation and ozonation process, the proposed PC process was highly cost-effective, providing a promising and new alternative for pretreatment of coking wastewater.

• Klíčová slova
• Biodegradability, Coking wastewater, Flow through, Graphene modified cathode, Peroxi-coagulation,
• MeSH
• chemické látky znečišťující vodu * MeSH
• fenol MeSH
• koks * MeSH
• odpad tekutý - odstraňování MeSH
• odpadní voda MeSH
• průmyslový odpad MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• chemické látky znečišťující vodu * MeSH
• fenol MeSH
• koks * MeSH
• odpadní voda MeSH
• průmyslový odpad MeSH

Biological degradability of ethylenediamine derivatives depends on the type and number of substituents. The susceptibility to biodegradation decreases in the sequence of substituents -COCH3, -CH3, -C2H5, -CH2CH2OH, -CH2COOH and with polysubstitution. The biodegradability depends also on the kind and number of nitrogen atoms. Complexing agents with a single-nitrogen atom in the molecule (e.g. NTA) succumb relatively readily to biodegradation whereas, compounds with two or more tertiary amino groups are biologically highly stable and do not undergo biodegradation even in experiments with activated sludge adapted at an age of up to 30 days (EDTA, DTPA, PDTA, HEDTA). A lowering of the degree of substitution brings about an increased susceptibility to biodegradation. This holds, e.g., for replacement of tertiary amino groups with secondary ones; thus the symmetrically disubstituted ethylenediamine-N,N'-diacetic acid (EDDA) possesses still sufficient complexing ability while belonging already to the group of potentially degradable substances.

• MeSH
• biodegradace MeSH
• chelátory * MeSH
• čištění vody metody   MeSH
• ethylendiaminy * MeSH
• kinetika MeSH
• kyseliny karboxylové MeSH
• nakládání s odpady metody   MeSH
• odpadní vody * MeSH
• vztahy mezi strukturou a aktivitou MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• chelátory * MeSH
• ethylendiaminy * MeSH
• kyseliny karboxylové MeSH
• odpadní vody * MeSH

The biological degradability (Zahn-Wellens test) of ethylenediamine derivatives with carboxymethyl and 2-hydroxyethyl groups was investigated. Mixed bacterial culture (activated sludge) was used as inoculum (non-adapted sludge and sludge adapted at different mean biomass retention time, the so-called sludge age). Biodegradability of ethylene(propylene)di(tri)amine-based complexing agents depends on the character and number of substituents and nitrogen atoms in the molecule. Tetra(penta)substituted derivatives with two or more tertiary nitrogen atoms and carboxymethyl or 2-hydroxyethyl groups in the molecule (EDTA, DTPA, PDTA, HEDTA) are very stable from an environmental point of view. On the contrary, disubstituted derivatives with two secondary nitrogen atoms in the molecule (e.g., EDDA) are potentially degradable.

• MeSH
• Bacteria MeSH
• biodegradace MeSH
• biomasa MeSH
• chelátory chemie   MeSH
• ethylendiaminy metabolismus   MeSH
• látky znečišťující půdu MeSH
• odpadní vody mikrobiologie   MeSH
• půdní mikrobiologie MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• chelátory MeSH
• ethylendiaminy MeSH
• ethylenediamine MeSH Prohlížeč
• látky znečišťující půdu MeSH
• odpadní vody MeSH

Structure-activity models for toxicity and biodegradability of groups of m-anilines and p-phenols were developed and compared. Hydrophobicity was the most important property in determining toxicity. Whereas, electronic and steric properties were the more important in modeling biodegradation.

• MeSH
• aniliny chemie   toxicita   MeSH
• biodegradace MeSH
• fenoly chemie   toxicita   MeSH
• kinetika MeSH
• metoda nejmenších čtverců MeSH
• vztahy mezi strukturou a aktivitou MeSH
• Publikační typ
• časopisecké články MeSH
• srovnávací studie MeSH
• Názvy látek
• aniliny MeSH
• fenoly MeSH

Biodegradable polymer-based therapeutics have recently become essential drug delivery biomaterials for various bioactive compounds. Biodegradable and biocompatible polymer-based biomaterials fulfill the requirements of these therapeutics because they enable to obtain polymer biomaterials with optimized blood circulation, pharmacokinetics, biodegradability, and renal excretion. Herein, we describe an adaptable polymerization platform employed for the synthesis of long-circulating, stimulus-sensitive and biodegradable biomaterials, therapeutics, or theranostics. Four chain transfer agents (CTA) were designed and successfully synthesized for the reversible addition-fragmentation chain transfer polymerization, allowing the straightforward synthesis of hydrolytically biodegradable structures of block copolymers-based biomaterials. The controlled polymerization using the CTAs enables controlling the half-life of the hydrolytic degradation of polymer precursors in a wide range from 5 h to 21 days. Moreover, the antitumor drug pirarubicin (THP) was successfully conjugated to the polymer biomaterials via a pH-sensitive hydrazone bond for in vitro and in vivo experiments. Polymer conjugates demonstrated superior antitumor efficacy compared to basic linear polymer-based conjugates. Notably, the biodegradable systems, even though those with degradation in the order of hours were selected, increased the half-life of THP in the bloodstream almost two-fold. Indeed, the presented platform design enables the main chain-end specific attachment of targeting ligands or diagnostic molecules. The adaptable polymerization platform design allows tuning of the biodegradability rate, stimuli-sensitive drug bonding, and optimized pharmacokinetics to increase the therapy outcome and system targeting, thus allowing the preparation of targeted or theranostic polymer conjugates. STATEMENT OF SIGNIFICANCE: Biodegradable and biocompatible polymer-based biomaterials are recognized as potential future bioactive nanomedicines. To advance the development of such biomaterials, we developed polymerization platforms utilizing tailored chain transfer agents allowing the straightforward synthesis of hydrolytically degradable polymer biomaterials with tuned biodegradability from hours to several days. The platform allows for the synthesis of long-circulating, stimulus-sensitive and biodegradable biomaterial serving as drug carriers or theranostics. The therapeutic potential was validated by preparation of polymer biomaterials containing pirarubicin, anticancer drug, bound via pH sensitive bond and by showing prolonged blood circulation and increased antitumor activity while keeping the drug side effects low. This work paves the way for future development of biodegradable polymer biomaterials with advanced properties in drug delivery.

• Klíčová slova
• CTA, Drug delivery, HPMA, Polymer carriers, RAFT polymerization,
• MeSH
• biokompatibilní materiály farmakologie   chemie   MeSH
• doxorubicin * chemie   MeSH
• nosiče léků chemie   MeSH
• polymerizace MeSH
• polymery chemie   MeSH
• protinádorové látky * terapeutické užití   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• biokompatibilní materiály MeSH
• doxorubicin * MeSH
• nosiče léků MeSH
• pirarubicin MeSH Prohlížeč
• polymery MeSH
• protinádorové látky * MeSH

Brominated flame retardants (BFRs) have been routinely used as additives in a number of consumer products for several decades in order to reduce the risk of fire accidents. Concerns about the massive use of these substances have increased due to their possible toxicity, endocrine disrupting properties and occurrence in almost all the environmental compartments, including humans and wildlife organisms. Several conventional BFRs (e.g. polybrominated diphenylethers (PBDE)) have been included in the list of Persistent Organic Pollutants and their use has been restricted because of their established toxicity and environmental persistence. Over the past few years, these compounds have been replaced with "new" BFRs (NBFRs). Despite the fact that NBFRs are different chemical molecules than traditional BFRs, most of physical-chemical properties (e.g. aromatic moiety, halogen substitution, lipophilic character) are common to both groups; therefore, their fate in the environment is potentially similar to the banned BFRs. Therefore, this article has been compiled to summarize the published scientific data regarding the biodegradability of the most widely used NBFRs, a key factor in their potential persistency in the environment, and their ecotoxicological effects on humans and test organisms. The data reviewed here document that the mechanisms through NBFRs exibit their ecotoxicity and the processes leading to their biotransformation in the environment are still poorly understood. Thus emphasis is placed on the need for further research in these areas is therefore emphasized, in order to avoid the massive use of further potentially harmful and recalcitrant substances of anthropogenic origin.

• Klíčová slova
• Biodegradation, Brominated flame retardants, Ecotoxicity, Legislative, Toxicity,
• MeSH
• biodegradace MeSH
• bromované uhlovodíky metabolismus   toxicita   MeSH
• hodnocení rizik MeSH
• lidé MeSH
• monitorování životního prostředí MeSH
• retardanty hoření metabolismus   toxicita   MeSH
• vystavení vlivu životního prostředí * MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• bromované uhlovodíky MeSH
• retardanty hoření MeSH

The aim of our research was to assess the ecotoxicity and biodegradability of leachates originating from two parts of a municipal landfill before and after biological treatment in the existing treatment plant. Biotests represent important tools for adequate environmental characterization of landfill leachates and could be helpful in reliable assessment and monitoring of the treatment plant efficiency. For ecotoxicity testing of landfill leachate before and after biological treatment, different organisms were chosen: the bacteria Vibrio fischeri, a mixed culture of activated sludge, duckweed Lemna minor, white mustard Sinapis alba, brine shrimp Artemia salina, and water flea Daphnia magna. For assessment of biodegradability, the method for determination of oxygen demand in a closed respirometer was used. The investigated leachates were heavily polluted, and in some cases, effluent limits were exceeded even after treatment. Results indicated that toxicity tests and physico-chemical parameters determined before and after treatment equivalently assess the efficiency of the existing treatment plant. However, the investigated leachates showed higher toxicity to Daphnia magna and especially to Lemna minor in contrast to Vibrio fischeri and Artemia salina (neither was sensitive to any of the leachates). No leachates were readily biodegradable. Experiments confirmed that the battery of toxicity tests should be applied for more comprehensive assessment of landfill leachate treatment and for reliable assessment of the treated leachate's subsequent environmental impact. It was confirmed that treated leachate, in spite of its better physico-chemical characteristics, still represents a potential environmental risk and thus should not be released into the environment.

• MeSH
• biodegradace MeSH
• bioreaktory MeSH
• chemické látky znečišťující vodu chemie   metabolismus   toxicita   MeSH
• měření biologické spotřeby kyslíku MeSH
• odpadní vody MeSH
• regenerace a remediace životního prostředí metody   MeSH
• testy toxicity MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• chemické látky znečišťující vodu MeSH
• odpadní vody MeSH

Chlorhexidine (CHX) and octenidine (OCT), antimicrobial compounds used in oral care products (toothpastes and mouthwashes), were recently revealed to interfere with human sex hormone receptor pathways. Experiments employing model organisms-white-rot fungi Irpex lacteus and Pleurotus ostreatus-were carried out in order to investigate the biodegradability of these endocrine-disrupting compounds and the capability of the fungi and their extracellular enzyme apparatuses to biodegrade CHX and OCT. Up to 70% ± 6% of CHX was eliminated in comparison with a heat-killed control after 21 days of in vivo incubation. An additional in vitro experiment confirmed manganese-dependent peroxidase and laccase are partially responsible for the removal of CHX. Up to 48% ± 7% of OCT was removed in the same in vivo experiment, but the strong sorption of OCT on fungal biomass prevented a clear evaluation of the involvement of the fungi or extracellular enzymes. On the other hand, metabolites indicating the enzymatic transformation of both CHX and OCT were detected and their chemical structures were proposed by means of liquid chromatography-mass spectrometry. Complete biodegradation by the ligninolytic fungi was not achieved for any of the studied analytes, which emphasizes their recalcitrant character with low possibility to be removed from the environment.

• Klíčová slova
• chlorhexidine, dental hygiene, laccase, ligninolytic fungi, manganese-dependent peroxidase, octenidine, personal care products, quaternary ammonium compounds, recalcitrant pollutant,
• MeSH
• antiinfekční látky lokální metabolismus   MeSH
• biodegradace * MeSH
• chlorhexidin chemie   metabolismus   MeSH
• houby metabolismus   MeSH
• iminy MeSH
• lidé MeSH
• metabolomika metody   MeSH
• pyridiny chemie   metabolismus   MeSH
• stomatologická péče MeSH
• transformace genetická MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• antiinfekční látky lokální MeSH
• chlorhexidin MeSH
• iminy MeSH
• octenidine MeSH Prohlížeč
• pyridiny MeSH

Herein, new biodegradable star polymer-doxorubicin conjugates designed for passive tumor targeting were investigated, and their synthesis, physico-chemical characterization, drug release, biodegradation, biodistribution and in vivo anti-tumor efficacy are described. In the conjugates, the core formed by poly(amidoamine) (PAMAM) dendrimers was grafted with semitelechelic N-(2-hydroxypropyl)methacrylamide (HPMA) copolymers bearing doxorubicin (Dox) attached by hydrazone bonds, which enabled intracellular pH-controlled drug release. The described synthesis facilitated the preparation of biodegradable polymer conjugates in a broad range of molecular weights (200-1000g/mol) while still maintaining low polydispersity (~1.7). The polymer grafts were attached to the dendrimers through either stable amide bonds or enzymatically or reductively degradable spacers, which enabled intracellular degradation of the high-molecular-weight polymer carrier to excretable products. Biodegradability tests in suspensions of EL4 T-cell lymphoma cells showed that the rate of degradation was much faster for reductively degradable conjugates (close to completion within 24h of incubation) than for conjugates linked via an enzymatically degradable oligopeptide GFLG sequence (slow degradation taking several days). This finding was likely due to the differences in steric hindrance in terms of the accessibility of the small molecule glutathione and the bulky enzyme cathepsin B to the polymer substrate. Regarding drug release, the conjugates were fairly stable in buffer at pH 7.4 (model of blood stream) but released doxorubicin under mild acidic conditions that model the tumor cell microenvironment. The star polymer-Dox conjugates exhibited significantly prolonged blood circulation and enhanced tumor accumulation in tumor-bearing mice, indicating the important role of the EPR effect in its anti-cancer activity. The star polymer conjugates showed prominently higher in vivo anti-tumor activities than the free drug or linear polymer conjugate when tested in mice bearing EL4 T-cell lymphoma, with a significant number of long-term surviving (LTS). Based on the results, we conclude that a M(w) of HPMA copolymers of 200,000 to 600,000g/mol is optimal for polymer carriers designed for the efficient passive targeting to solid tumors. In addition, an expressive therapy-dependent stimulation of the immune system was observed.

• MeSH
• biokompatibilní materiály chemie   metabolismus   MeSH
• dendrimery chemie   metabolismus   MeSH
• doxorubicin chemie   metabolismus   farmakokinetika   terapeutické užití   MeSH
• lidé MeSH
• lymfom farmakoterapie   MeSH
• methakryláty chemie   metabolismus   MeSH
• myši MeSH
• nádorové buněčné linie MeSH
• protinádorová antibiotika chemie   metabolismus   farmakokinetika   terapeutické užití   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• biokompatibilní materiály MeSH
• dendrimery MeSH
• doxorubicin MeSH
• hydroxypropyl methacrylate MeSH Prohlížeč
• methakryláty MeSH
• PAMAM Starburst MeSH Prohlížeč
• protinádorová antibiotika MeSH