UV cross-linked polyvinylpyrrolidone electrospun fibres as antibacterial surfaces

Many bacteria become progressively more resistant to antibiotics and it remains a challenging task to control their overall levels. Polymers combined with active biomolecules come to the forefront for the design of antibacterial materials that can address this encounter. In this work, we investigated the photo-crosslinking approach of UV-sensitive benzophenone molecule (BP) with polyvinylpyrrolidone (PVP) polymer within electrospun fibres. The BP and PVP solutions allowed fabricating polymer mats that were subsequently functionalised with antibacterial lysozyme. The physical properties of the crosslinked electrospun fibres were investigated by scanning electron microscopy and atomic force microscopy. The average diameter of the obtained fibres decreased from 290 ± 50 nm to 270 ± 70 nm upon the addition of the crosslinking molecules and then to 240 ± 80 nm and 180 ± 90 nm after subsequent crosslinking reaction at an increasing time: 3 and 5 h, respectively. The peak force quantitative nanomechanical mapping (PF-QNM) indicated the increase of DMT modulus of obtained cross-linked fibres from 4.1 ± 0.8 GPa to 7.2 ± 0.5 GPa. Furthermore, the successful crosslinking reaction of PVP and BP solution into hydrogels was investigated in terms of examining photo-crosslinking mechanism and was confirmed by rheology, Raman, Fourier transform infrared and nuclear magnetic resonance. Finally, lysozyme was successfully encapsulated within cross-linked PVP-BP hydrogels and these were successfully electrospun into mats which were found to be as effective antibacterial agents as pure lysozyme molecules. The dissolution rate of photo cross-linked PVP mats was observed to increase in comparison to pure PVP electrospun mats which opened a potential route for their use as antibacterial, on-demand, dissolvable coatings for various biomedical applications

Biomaterials applications of cyclic polymers

Cyclic polymers are an intriguing class of polymers due to their lack of chain ends. This unique architecture combined with steric constraints adorn cyclic polymers as well as nano-, micro- and macro-scale materials containing cyclic polymers with distinctive physicochemical properties which can have a profound effect on the performance of these materials in a wide range of applications. Within a biomedical context, biomaterials based on cyclic polymers have shown very distinct properties in terms of biodistribution, pharmacokinetics, drug/gene delivery efficiency and surface activity. This review summarizes the applications of cyclic polymers in the field of biomaterials and highlights their potential in the biomedical field as well as addressing future challenges in this area

The Threat to the Environment from the Environment Protection Facilities. Part 2. Characteristics of Existing Threats and Some Possibilities of their Reduction

W artykule omówiono zagrożenia dla środowiska występujące w trzech oczyszczalniach ścieków miejskich, których elementem składowym schematu technologicznego jest beztlenowa przeróbka osadów ściekowych z produkcją biogazu. Podstawowym elementem, który chroni oczyszczalnie ścieków, jest środowisko wodne. Prawidłowa praca oczyszczalni nie stanowi zagrożenia dla tego środowiska. Natomiast zagrożenie dla powietrza atmosferycznego oraz zagrożenie pożarem i wybuchem występuje w tych oczyszczalniach bez względu na warunki eksploatacji. W artykule omówiono rodzaje występujących zagrożeń: dla jakości powietrza atmosferycznego, ze stronnych hałasu, a także związanych z pożarem i wybuchem. Podano stosowane w każdej z trzech ocenianych oczyszczalni środki i zabiegi zmierzające do ograniczenia zagrożeń.The article discusses the threat to the environment which is posed by the three wastewater treatment plants (WWTP) with anaerobic digestion of the wastewater sludge and biogas production . The surface water is the main environmental element, protecting the WWTP. The normal use of the WWTP does not pose a threat to it . Despite the conditions of plant work there is always a risk of the contamination of atmospheric air with methane, the threat of fire or explosions . The article discusses the following types of threats: • the threat for the atmospheric air, • the threat coming from the noise • the threat of fire and explosions. The methods for the reduction of the above mentioned types of threats applied in each plant were described

Ten-year outcomes after coronary artery bypass grafting according to age in patients with heart failure and left ventricular systolic dysfunction: an analysis of the extended follow-up of the STICH Trial (Surgical Treatment for Ischemic Heart Failure)

BACKGROUND: Advancing age is associated with a greater prevalence of coronary artery disease in heart failure with reduced ejection fraction and with a higher risk of complications after coronary artery bypass grafting (CABG). Whether the efficacy of CABG compared with medical therapy (MED) in patients with heart failure caused by ischemic cardiomyopathy is the same in patients of different ages is unknown. METHODS: A total of 1212 patients (median follow-up, 9.8 years) with ejection fraction ≤35% and coronary disease amenable to CABG were randomized to CABG or MED in the STICH trial (Surgical Treatment for Ischemic Heart Failure). RESULTS: Mean age at trial entry was 60 years; 12% were women; 36% were nonwhite; and the baseline ejection fraction was 28%. For the present analyses, patients were categorized by age quartiles: quartile 1, ≤54 years; quartile, 2 >54 and ≤60 years; quartile 3, >60 and ≤67 years; and quartile 4, >67 years. Older versus younger patients had more comorbidities. Allcause mortality was higher in older compared with younger patients assigned to MED (79% versus 60% for quartiles 4 and 1, respectively; log-rank P=0.005) and CABG (68% versus 48% for quartiles 4 and 1, respectively; log-rank P<0.001). In contrast, cardiovascular mortality was not statistically significantly different across the spectrum of age in the MED group (53% versus 49% for quartiles 4 and 1, respectively; log-rank P=0.388) or CABG group (39% versus 35% for quartiles 4 and 1, respectively; log-rank P=0.103). Cardiovascular deaths accounted for a greater proportion of deaths in the youngest versus oldest quartile (79% versus 62%). The effect of CABG versus MED on all-cause mortality tended to diminish with increasing age (Pinteraction=0.062), whereas the benefit of CABG on cardiovascular mortality was consistent over all ages (Pinteraction=0.307). There was a greater reduction in all-cause mortality or cardiovascular hospitalization with CABG versus MED in younger compared with older patients (Pinteraction=0.004). In the CABG group, cardiopulmonary bypass time or days in intensive care did not differ for older versus younger patients. CONCLUSIONS: CABG added to MED has a more substantial benefit on all-cause mortality and the combination of all-cause mortality and cardiovascular hospitalization in younger compared with older patients. CABG added to MED has a consistent beneficial effect on cardiovascular mortality regardless of age

Ten-Year Outcomes After Coronary Artery Bypass Grafting According to Age in Patients With Heart Failure and Left Ventricular Systolic Dysfunction

BACKGROUND: Advancing age is associated with a greater prevalence of coronary artery disease in heart failure with reduced ejection fraction and with a higher risk of complications after coronary artery bypass grafting (CABG). Whether the efficacy of CABG compared with medical therapy (MED) in patients with heart failure caused by ischemic cardiomyopathy is the same in patients of different ages is unknown. METHODS: A total of 1212 patients (median follow-up, 9.8 years) with ejection fraction ≤35% and coronary disease amenable to CABG were randomized to CABG or MED in the STICH trial (Surgical Treatment for Ischemic Heart Failure). RESULTS: Mean age at trial entry was 60 years; 12% were women; 36% were nonwhite; and the baseline ejection fraction was 28%. For the present analyses, patients were categorized by age quartiles: quartile 1, ≤54 years; quartile, 2 >54 and ≤60 years; quartile 3, >60 and ≤67 years; and quartile 4, >67 years. Older versus younger patients had more comorbidities. Allcause mortality was higher in older compared with younger patients assigned to MED (79% versus 60% for quartiles 4 and 1, respectively; log-rank P=0.005) and CABG (68% versus 48% for quartiles 4 and 1, respectively; log-rank P<0.001). In contrast, cardiovascular mortality was not statistically significantly different across the spectrum of age in the MED group (53% versus 49% for quartiles 4 and 1, respectively; log-rank P=0.388) or CABG group (39% versus 35% for quartiles 4 and 1, respectively; log-rank P=0.103). Cardiovascular deaths accounted for a greater proportion of deaths in the youngest versus oldest quartile (79% versus 62%). The effect of CABG versus MED on all-cause mortality tended to diminish with increasing age (Pinteraction=0.062), whereas the benefit of CABG on cardiovascular mortality was consistent over all ages (Pinteraction=0.307). There was a greater reduction in all-cause mortality or cardiovascular hospitalization with CABG versus MED in younger compared with older patients (Pinteraction=0.004). In the CABG group, cardiopulmonary bypass time or days in intensive care did not differ for older versus younger patients. CONCLUSIONS: CABG added to MED has a more substantial benefit on all-cause mortality and the combination of all-cause mortality and cardiovascular hospitalization in younger compared with older patients. CABG added to MED has a consistent beneficial effect on cardiovascular mortality regardless of age