Correlative atomic force microscopy and scanning electron microscopy of bacteria-diamond-metal nanocomposites.

Research investigating the interface between biological organisms and nanomaterials nowadays requires multi-faceted microscopic methods to elucidate the interaction mechanisms and effects. Here we describe a novel approach and methodology correlating data from an atomic force microscope inside a scanning electron microscope (AFM-in-SEM). This approach is demonstrated on bacteria-diamond-metal nanocomposite samples relevant in current life science research. We describe a procedure for preparing such multi-component test samples containing E. coli bacteria and chitosan-coated hydrogenated nanodiamonds decorated with silver nanoparticles on a carbon-coated gold grid. Microscopic topography information (AFM) is combined with chemical, material, and morphological information (SEM using SE and BSE at varied acceleration voltages) from the same region of interest and processed to create 3D correlative probe-electron microscopy (CPEM) images. We also establish a novel 3D RGB color image algorithm for merging multiple SE/BSE data from SEM with the AFM surface topography data which provides additional information about microscopic interaction of the diamond-metal nanocomposite with bacteria, not achievable by individual analyses. The methodology of CPEM data interpretation is independently corroborated by further in-situ (EDS) and ex-situ (micro-Raman) chemical characterization as well as by force volume AFM analysis. We also discuss the broader applicability and benefits of the methodology for life science research.

Absolute energy levels in nanodiamonds of different origins and surface chemistries.

Nanodiamonds (NDs) are versatile, broadly available nanomaterials with a set of features highly attractive for applications from biology over energy harvesting to quantum technologies. Via synthesis and surface chemistry, NDs can be tuned from the sub-micron to the single-digit size, from conductive to insulating, from hydrophobic to hydrophilic, and from positively to negatively charged surface by simple annealing processes. Such ND diversity makes it difficult to understand and take advantage of their electronic properties. Here we present a systematic correlated study of structural and electronic properties of NDs with different origins and surface terminations. The absolute energy level diagrams are obtained by the combination of optical (UV-vis) and photoelectron (UPS) spectroscopies, Kelvin probe measurements, and energy-resolved electrochemical impedance spectroscopy (ER-EIS). The energy levels and density of states in the bandgap of NDs are correlated with the surface chemistry and structure characterized by FTIR and Raman spectroscopy. We show profound differences in energy band shifts (by up to 3 eV), Fermi level position (from p-type to n-type), electron affinity (from +0.5 eV to -2.2 eV), optical band gap (5.2 eV to 5.5 eV), band gap states (tail or mid-gap), and electrical conductivity depending on the high-pressure, high-temperature and detonation origin of NDs as well as on the effects of NDs' oxidation, hydrogenation, sp2/sp3 carbon phases and surface adsorbates. These data are fundamental for understanding and designing NDs' optoelectrochemical functional mechanisms in diverse application areas.

Disability and the (dysbiotic) gut: Sensing, tasting and knowing with food.

This article offers insights into eating practices, conceptualising and making of 'good' food by people living with chronic disease. Based on ethnographic research focussing on people with Inflammatory Bowel Disease (Crohn's disease, ulcerative colitis and undefined IBD) in the Czech Republic, we explore what it would mean to conceptualise disability from the non-normative gut. We trace the practices of tinkering with foods and one's body, and ways of learning to sense (with) dysbiotic guts that people with IBD develop. Departing from the established notions of digestion and metabolism as universal biological processes, people with IBD create an embodied crip archive of knowledge through their eating practices, ways of making and sensing food and metabolic sampling. Most importantly, these practices offer, as we argue, new pathways into exploring crip embodiments as a place from which to acknowledge and do more-than-human collaboration, heath and ecologies.

Sympoietic growth: living and producing with fungi in times of ecological distress.

Drawing upon ethnographic research on human living and producing with fungi, and Haraway's theorization of sympoiesis and the model ecosystems of mycorrhizae developed in current mycological research, we offer a concept of sympoietic growth. Sympoiesis is a concept that suggests a way of thinking about growth as a more-than-human process and provides an alternative political imaginary both to current forms of economic growth and to the idea of "degrowth." We explore human-fungi co-operation in forests, an urban park, and a shopping mall, on a miso production farm, and in a Catholic parish to provide insights into the logic and relationships involved in sympoietic growth in the field of agriculture and food production. We argue that this form of food provision has a sustainable, (re)generative potential not only in ecological and social but also economic terms. In conclusion, we highlight three patterns of sympoietic growth: the absence of any urge to "take (back) control" over the multispecies dynamic on the part of the humans; a non-instrumental passion for more-than-human life; and a combination of intellectual and manual labor as a form of attachment to the more-than-human world.

How barefoot and conventional shoes affect the foot and gait characteristics in toddlers.

OBJECTIVES: Barefoot shoes have recently become a popular alternative to conventional shoes among the parents of pre-school children. As the long-term effect of habitual shoe-wearing on the foot is still unclear, the aim of this study was to compare the arch index, dynamic foot anthropometry and gait parameters in toddlers who had been habitually wearing barefoot shoes or conventional shoes since their first steps. METHODS: 30 toddlers- 15 habitually wearing barefoot shoes (BF group) and 15 habitually wearing conventional shoes (N-BF group)-participated in this study. Each child was measured twice during the study. The first data collection session occurred within one month after the first five consecutive unsupported steps were performed by the toddler. The second data collection session occurred seven months after this event. At each data collection session, the toddler was instructed to walk barefooted at its natural speed over an Emed® platform (Novel GmbH, Germany). The Emed ® software generated data regarding the arch index, dynamic foot anthropometry, foot progression angle, contact area, contact time, peak pressure and maximum force. The Wilcoxon signed-rank test was used to compare the differences between the 1st and 2nd data collections. The Mann-Whitney U test was used to compare the differences between the BF and N-BF groups. RESULTS: The results of this study show a higher plantar arch and a smaller foot progression angle in the BF group. The forefoot width in both the BF and N-BF groups remained proportional to the foot length after seven months of independent walking. CONCLUSIONS: These findings may encourage parents and caregivers to introduce barefoot shoes or create a habitual barefoot time for their child.

Search for a time- and cost-saving genetic testing strategy for maturity-onset diabetes of the young.

AIMS: Correct genetic diagnosis of maturity-onset diabetes of the young (MODY) is beneficial for person's diabetes management compared to no genetic testing. Aim of the present study was a search for optimal time- and cost-saving strategies by comparing two approaches of genetic testing of participants with clinical suspicion of MODY. METHODS: A total of 121 consecutive probands referred for suspicion of MODY (Group A) were screened using targeted NGS (tNGS), while the other 112 consecutive probands (Group B) underwent a single gene test based on phenotype, and in cases of negative findings, tNGS was conducted. The study was performed in two subsequent years. The genetic results, time until reporting of the final results and financial expenses were compared between the groups. RESULTS: MODY was confirmed in 30.6% and 40.2% probands from Groups A and B, respectively; GCK-MODY was predominant (72.2% in Group A and 77.8% in Group B). The median number of days until results reporting was 184 days (IQR 122-258) in Group A and 91 days (44-174) in Group B (p < 0.00001). Mean costs per person were higher for Group A (639 ± 30 USD) than for Group B (584 ± 296 USD; p = 0.044). CONCLUSIONS: The two-step approach represented a better strategy for genetic investigation of MODY concerning time and costs compared to direct tNGS. Although a single-gene investigation clarified the diabetes aetiology in the majority of cases, tNGS could reveal rare causes of MODY and expose possible limitations of both standard genetic techniques and clinical evaluation.

Association of Genetic Variants Affecting microRNAs and Pancreatic Cancer Risk.

Genetic factors play an important role in the susceptibility to pancreatic cancer (PC). However, established loci explain a small proportion of genetic heritability for PC; therefore, more progress is needed to find the missing ones. We aimed at identifying single nucleotide polymorphisms (SNPs) affecting PC risk through effects on micro-RNA (miRNA) function. We searched in silico the genome for SNPs in miRNA seed sequences or 3 prime untranslated regions (3'UTRs) of miRNA target genes. Genome-wide association data of PC cases and controls from the Pancreatic Cancer Cohort (PanScan) Consortium and the Pancreatic Cancer Case-Control (PanC4) Consortium were re-analyzed for discovery, and genotyping data from two additional consortia (PanGenEU and PANDoRA) were used for replication, for a total of 14,062 cases and 11,261 controls. None of the SNPs reached genome-wide significance in the meta-analysis, but for three of them the associations were in the same direction in all the study populations and showed lower value of p in the meta-analyses than in the discovery phase. Specifically, rs7985480 was consistently associated with PC risk (OR = 1.12, 95% CI 1.07-1.17, p = 3.03 × 10-6 in the meta-analysis). This SNP is in linkage disequilibrium (LD) with rs2274048, which modulates binding of various miRNAs to the 3'UTR of UCHL3, a gene involved in PC progression. In conclusion, our results expand the knowledge of the genetic PC risk through miRNA-related SNPs and show the usefulness of functional prioritization to identify genetic polymorphisms associated with PC risk.

Long-term donor-site morbidity after thumb reconstruction with twisted-toe technique.

BACKGROUND: Traumatic thumb loss is a serious injury affecting patient´s ability to work and participate in activities of daily life. The main goal for a plastic surgeon is to restore hand grip, often by microsurgical methods. However, patients should be informed of all effects associated with tissue harvesting. The aim of the study was to assess the impact on donor foot and gait cycle in patients who have undergone thumb reconstruction using twisted-toe technique modified by Kempný. MATERIAL AND METHODS: Twelve patients participated in the study: all suffered a thumb loss between the years 2003 and 2011 and the twisted-toe technique for thumb reconstruction was utilized. The changes in foot pressure distribution and lower extremity joint loading were evaluated. RESULTS: The differences in total maximal plantar pressure, pressure time integral, contact area, and maximum force between the affected and non-affected foot were statistically significant (P 0.1). No significant differences of temporal gait parameters between the affected and non-affected extremity were observed; however, statistically significant differences in kinetics parameters, frontal ankle and knee moments were detected. CONCLUSION: Donor limb functionality and anatomical disability were assessed using pedobarography systems and 3D-gait analysis. The recorded differences in plantar pressure distribution (increased pressure in I., IV. and V. metatarsal areas) and overload of the medial compartment of the knee joint were the most significant findings. Therefore, wearing individually adapted shoe insoles as prevention of osteoarthrosis might be beneficial for patients after thumb reconstruction by a twisted-toe technique.

Growth Inhibition of Gram-Positive and Gram-Negative Bacteria by Zinc Oxide Hedgehog Particles.

PURPOSE: Nanomaterials for antimicrobial applications have gained interest in recent years due to the increasing bacteria resistance to conventional antibiotics. Wound sterilization, water treatment and surface decontamination all avail from multifunctional materials that also possess excellent antibacterial properties, eg zinc oxide (ZnO). Here, we assess and compare the effects of synthesized hedgehog-like ZnO structures and commercial ZnO particles with and without mixing on the inactivation of bacteria on surfaces and in liquid environments. METHODS: Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria in microbial culture medium were added to reverse spin bioreactors that contained different concentrations of each ZnO type to enable dynamic mixing of the bacteria-ZnO suspensions. Optical density of the bacteria-ZnO suspensions was measured in real-time and the number of viable bacteria after 24 h exposure was determined using standard microbiological techniques. The concentration of zinc ion generated from ZnO dissolution in different liquid types was estimated from the dynamic interaction exposure. Static antibacterial tests without agitation in liquid media and on agar surface were performed for comparison. RESULTS: A correlation between increasing ZnO particle concentration and reduction in viable bacteria was not monotonous. The lowest concentration tested (10 µg/mL) even stimulated bacteria growth. The hedgehog ZnO was significantly more antibacterial than commercial ZnO particles at higher concentrations (up to 1000 µg/mL tested), more against E. coli than S. aureus. Minimum inhibitory concentration in microwell plates was correlated with those results. No inhibition was detected for any ZnO type deposited on agar surface. Zinc ion release was greatly suppressed in cultivation media. Scanning electron microscopy images revealed that ZnO needles can pierce membrane of bacteria whereas the commercial ZnO nanoparticles rather agglomerate on the cell surface. CONCLUSION: The inhibition effects are thus mainly controlled by the interaction dynamics between bacteria and ZnO, where mixing greatly enhances antibacterial efficacy of all ZnO particles. The efficacy is modulated also by ZnO particle shapes, where hedgehog ZnO has superior effect, in particular at lower concentrations. However, at too low concentrations, ZnO can stimulate bacteria growth and must be thus used with caution.

The Impact of Different Periods of Walking Experience on Kinematic Gait Parameters in Toddlers.

This study aimed to analyse the kinematic differences in gait between three groups of toddlers who differed in their weeks of independent walking (IW) experience, but not in anthropometrical characteristics, to determine the relationship between walking experience without the side effect of morphological differences on gait parameters. Twenty-six toddlers participated in this study. Depending on the week of their IW, toddlers were divided into three groups: Group 1 (1-5 weeks of IW), Group 2 (6-10 weeks of IW), and Group 3 (11-15 weeks of IW). Each toddler walked barefooted over a 2-m long pathway, and 3D kinematic data were obtained. A decrease in the upper limb position, hip flexion, and step width, i.e., changes towards the adult gait pattern, were observed in Group 3. Less experienced walkers exhibited a wider step width despite no statistically significant difference in body mass and height between groups. Results of this study show no statistically significant difference in step length between groups, suggesting that step length is more related to height than to the walking experience. The increased step length in more experienced walkers reported in previous studies may therefore be a result of different heights and not walking experience.

Targeted Sequencing of Pancreatic Adenocarcinomas from Patients with Metachronous Pulmonary Metastases.

Mutation spectra of 250 cancer driver, druggable, and actionable genes were analyzed in surgically resected pancreatic ductal adenocarcinoma (PDAC) patients who developed metachronous pulmonary metastases. Targeted sequencing was performed in DNA from blood and archival samples of 15 primary tumors and three paired metastases. Results were complemented with the determination of G12V mutation in KRAS by droplet digital PCR. The median number of protein-changing mutations was 52 per patient. KRAS and TP53 were significantly enriched in fractions of mutations in hotspots. Individual gene mutation frequencies or mutational loads accounting separately for drivers, druggable, or clinically actionable genes, did not significantly associate with patients' survival. LRP1B was markedly mutated in primaries of patients who generalized (71%) compared to those developing solitary pulmonary metastases (0%). FLG2 was mutated exclusively in primary tumors compared to paired metastases. In conclusion, signatures of prognostically differing subgroups of PDAC patients were generated for further utilization in precision medicine.

Effects of Bacterial Nanocellulose Loaded with Curcumin and Its Degradation Products on Human Dermal Fibroblasts.

Bacterial nanocellulose has found applications in tissue engineering, in skin tissue repair, and in wound healing. Its large surface area enables the adsorption of various substances. Bacterial nanocellulose with adsorbed substances can serve as a substrate for drug-delivery of specific bioactive healing agents into wounds. In this study, we loaded a bacterial nanocellulose hydrogel with curcumin, i.e., an important anti-bacterial and healing agent, and its degradation products. These products were prepared by thermal decomposition of curcumin (DC) at a temperature of 180 °C (DC 180) or of 300 °C (DC 300). The main thermal decomposition products were tumerone, vanillin, and feruloylmethane. Curcumin and its degradation products were loaded into the bacterial nanocellulose by an autoclaving process. The increased temperature during autoclaving enhanced the solubility and the penetration of the agents into the nanocellulose. The aim of this study was to investigate the cytotoxicity and the antimicrobial activity of pure curcumin, its degradation products, and finally of bacterial nanocellulose loaded with these agents. In vitro tests performed on human dermal fibroblasts revealed that the degradation products of curcumin, i.e., DC 180 and DC 300, were more cytotoxic than pure curcumin. However, if DC 300 was loaded into nanocellulose, the cytotoxic effect was not as strong as in the case of DC 300 powder added into the culture medium. DC 300 was found to be the least soluble product in water, which probably resulted in the poor loading of this agent into the nanocellulose. Nanocellulose loaded with pure curcumin or DC 180 exhibited more antibacterial activity than pristine nanocellulose.

3D kinematic analysis of patients' gait before and after unilateral total hip replacement.

PURPOSE: The purpose of the study was to describe changes in the kinematic parameters in the patients' gait after total hip replacement. METHODS: Research group of men in the end stage of osteoarthritis indicated to the THR (n = 10; age 54.1 ± 7.5 years; weight 92.2 ± 9.6 kg; height 179.7 ± 5.9 cm). All participants underwent a total of three measurements: before surgery, 3 and 6 months after the surgery. Using the 3D kinematic analysis system, the patients' gait was recorded during each measurement session and kinematic analysis was carried out. The parameters that were monitored included the sagittal range of motion while walking in the ankle, the knee and the hip joints of the operated and the unoperated limb, and the range in the hip joint's frontal plane, the rotation of pelvis in the frontal and transverse planes, as well as the speed of walking and the walking step length. RESULTS: Significant increases were found in sagittal range of motion in the operated hip joint, sagittal range of motion in the ankle joint on the unoperated side and in the walking step length of the unoperated limb. CONCLUSIONS: During walking after a THR, the sagittal range of motion in the ankle of the unoperated limb increases. Also, the range of motion in the sagittal plane on the operated joint increases, which is related to the lengthening of the step of the unoperated lower limb.

A new way to prepare gold nanoparticles by sputtering - Sterilization, stability and other properties.

We have developed a novel simple method for effective preparing gold nanoparticles (AuNPs) intended for utilization in biomedicine. The method is based on gold sputtering into liquid poly(ethylene glycol) (PEG). The PEG was used as a basic biocompatible stabilizer of the AuNP colloid. In addition, two naturally occurring polysaccharides - Chitosan (Ch) and Methylcellulose (MC) - were separately diluted into the PEG base with the aims to enhance the yield of the sputtering without changing the sputtering parameters, and to further improve the stability and the biocompatibility of the colloid. The colloids were sterilized by steam, and their stability was measured before and after the sterilization process by dynamic light scattering and UV-Vis spectrophotometry. The results indicated a higher sputtering yield in the colloids containing the polysaccharides. The colloids were also characterized by atomic absorption spectroscopy (AAS) to reveal the composition of the prepared nanoparticles by transmission electron microscopy (TEM) to visualize the nanoparticles and to evaluate their size and clustering, and by rheometry to estimate the viscosity of the colloids. The zeta-potential of the AuNPs was also determined as an important parameter indicating the stability and the biocompatibility of the colloid. In addition, in vitro tests of antimicrobial activity and cytotoxicity were carried out to estimate the biological activity and the biocompatibility of the colloids. Antimicrobial tests were performed by a drip test on two bacterial strains - Gram-positive Staphylococcus epidermidis and Gram-negative Escherichia coli. AuNP with chitosan proved to possess the highest antibacterial activity, especially towards the Gram-positive S. epidermidis. In vitro tests on eukaryotic cells, i.e. human osteoblastic cell line SAOS-2 and primary normal human dermal fibroblasts (NHDF), were performed after a 7-day cultivation to determine the effect and the toxic dose of the colloids on human cells. The studied colloid concentrations were in the range from 0.6 µg/ml to 6 µg/ml. Toxicity of the colloids started to reappear at a concentration of 4.5 µg/ml, especially with chitosan in the colloid, where the colloid with a concentration of 6 µg/ml proved to be the most toxic, especially towards the SAOS-2 cell line. However, the PEG and PEG-MC containing colloids proved to be relatively non-toxic, even at the highest concentration, but with a slowly decreasing tendency of the cell metabolic activity.

Special footwear designed for pregnant women and its effect on kinematic gait parameters during pregnancy and postpartum period.

During pregnancy, an array of changes occurs in women body to enable the growth and development of the future baby and the consequent delivery. These changes are reflected in the range of motion of trunk, pelvis, lower limbs and other body segments, affect the locomotion and some of these changes may persist to the postpartum period. The aim of this study was to describe the changes affecting the gait during pregnancy and to determine the effect of tested footwear on kinematic gait characteristics during pregnancy as previous studies indicate that special orthopaedic insoles and footwear might be useful in prevention of the common musculoskeletal pain and discomfort related to pregnancy. Participants from the control group (n = 18), without any intervention, and the experimental group (n = 23), which was wearing the tested shoes, were measured at their 14, 28 and 37 gestational weeks and 28 weeks postpartum to capture the complete pregnancy-related changes in gait. The gait 3D kinematic data were obtained using Simi Motion System. The differences between the control and experimental group at the first data collection session in most of the analysed variables, as well as relatively high standard deviations of analysed variables indicate large individual differences in the gait pattern. The effect of tested footwear on kinematic gait pattern changes may be explained by its preventive effect against the foot arches falling. In the control group, changes associated previously with the foot arches falling and hindfoot hyperpronation were observed during advanced phases of pregnancy and postpartum, e.g. increase in knee flexion or increase in spinal curvature. For the comprehensive evaluation of the tested footwear on pregnancy gait pattern, future studies combining the kinematic and dynamic plantographic methods are needed.

Versatile Application of Nanocellulose: From Industry to Skin Tissue Engineering and Wound Healing.

Nanocellulose is cellulose in the form of nanostructures, i.e., features not exceeding 100 nm at least in one dimension. These nanostructures include nanofibrils, found in bacterial cellulose; nanofibers, present particularly in electrospun matrices; and nanowhiskers, nanocrystals, nanorods, and nanoballs. These structures can be further assembled into bigger two-dimensional (2D) and three-dimensional (3D) nano-, micro-, and macro-structures, such as nanoplatelets, membranes, films, microparticles, and porous macroscopic matrices. There are four main sources of nanocellulose: bacteria (Gluconacetobacter), plants (trees, shrubs, herbs), algae (Cladophora), and animals (Tunicata). Nanocellulose has emerged for a wide range of industrial, technology, and biomedical applications, namely for adsorption, ultrafiltration, packaging, conservation of historical artifacts, thermal insulation and fire retardation, energy extraction and storage, acoustics, sensorics, controlled drug delivery, and particularly for tissue engineering. Nanocellulose is promising for use in scaffolds for engineering of blood vessels, neural tissue, bone, cartilage, liver, adipose tissue, urethra and dura mater, for repairing connective tissue and congenital heart defects, and for constructing contact lenses and protective barriers. This review is focused on applications of nanocellulose in skin tissue engineering and wound healing as a scaffold for cell growth, for delivering cells into wounds, and as a material for advanced wound dressings coupled with drug delivery, transparency and sensorics. Potential cytotoxicity and immunogenicity of nanocellulose are also discussed.

Antimicrobial and photophysical properties of chemically grafted ultra-high-molecular-weight polyethylene.

Surface of ultra-high-molecular-weight polyethylene (UHMWPE) was modified by chemical methods. Surface was firstly activated by Piranha solution and then grafted with selected amino-compounds (cysteamine, ethylenediamine or chitosan). The next step was grafting of some borane cluster compounds, highly fluorescent borane hydride cluster anti-B18H22 or its thiolated derivative 4,4'-(HS)2-anti-B18H20. Polymer foils were studied using various methods to characterize surface chemistry (X-ray photoelectron spectroscopy), roughness and morphology (atomic force microscopy, scanning electron microscopy), chemistry and polarity (electrokinetic analysis), wettability (goniometry) and photophysical properties (UV-Vis spectroscopy) before and after modification steps. Subsequently some kinds of antimicrobial tests were performed. Immobilization of anti-B18H22 in small quantities onto UHMWPE surface leads to materials with a luminescence. Samples grafted with borane clusters showed significant inhibition of growth for gram-positive bacteria (S. epidermidis). These approaches can be used for (i) luminophores on the base of polymers nanocomposites development and/or (ii) preparation of materials with antimicrobial effects.

Preparation of surfaces of composite samples for tip based micro-analyses using ion beam milling.

Ion beam milling, as a method of surface design for tip analytical techniques, was explored. A sample of clay, embedded in a resin, was treated by the ion beam and allowed AFM (a typical tip technique) to be successfully applied. The method is suitable for advanced tip analyses based on AFM, like TERS or SNOM, and for samples that are not possible to prepare by standard mechanical methods. The approach can be useful for characterisation of the surfaces of many different types of materials in versatile applications such as catalysis, corrosion science or advanced material characterisation.

Reaction parameters of in situ silver chloride precipitation on cellulose fibres.

In the present work, non-woven, non-regenerated cellulose wound dressing was subjected to in situ silver (Ag) deposition in the form of silver chloride (AgCl) under various reaction conditions. The studied reaction parameters were as follows: time, temperature, and reactants´ concentration. AgCl was bound on the cellulose via two-step process. Firstly, the silver ions (Ag+) were attracted to cellulose in the solution of silver nitrate (AgNO3). Secondly, Ag+ were precipitated directly on the cellulose by immersing the samples into the solution of sodium chloride (NaCl). The prepared samples were examined on the amount of bound and released Ag, and the release was studied both in water and in simulated body fluids. The reaction parameters significantly affected the amount of bound and released Ag, the difference of released Ag was as high as 75%. The key parameter in the process was reactants´ concentration. Non-regenerated cellulose modified with AgCl was antibacterially active.

Antimicrobial and optical properties of PET chemically modified and grafted with borane compounds.

Polyethylene terephthalate (PET) foils were activated with piranha solution and grafted with selected amino compounds (cysteamine, ethylenediamine or chitosan) and then with borane compounds. Changes in their surface properties after particular modification steps were examined using electrokinetic analysis, X-ray photoelectron spectroscopy (XPS), goniometry and UV-vis spectroscopy. Several tests showed that the presence of some amino compounds and one borane cluster significantly improved the antimicrobial properties of the composites investigated. In particular, they exhibited strong antibacterial activity against Staphylococcus epidermidis but only weak activity against Escherichia coli. The samples modified with amino compounds and subsequently with borane clusters were luminescent under UV lamp irradiation. Therefore, the nanocomposites consisting of (cheap) polymer and (more expensive) borane could be used in luminophore development, medicine or environmental protection.