Ewolucja systemu uubezpieczeń społecznych w Polsce Ludowej

Zadanie pt. „Digitalizacja i udostępnienie w Cyfrowym Repozytorium Uniwersytetu Łódzkiego kolekcji czasopism naukowych wydawanych przez Uniwersytet Łódzki” nr 885/P-DUN/2014 dofinansowane zostało ze środków MNiSW w ramach działalności upowszechniającej naukę

Microwave-enhanced synthesis of biodegradable multifunctional chitosan hydrogels for wastewater treatment

Chitosan, a derivative of chitin, is a biodegradable polymer known of its favorable properties, applicable in medicine and industry. Commonly obtained chitosan hydrogels are of various swelling capacity, and may bind only anions losing their susceptibility to biodegradation. Hydrogels are mostly obtained using toxic crosslinkers, which pollute environment due to waste generation during their synthesis. In the present article a novel, waste-free method for obtaining chitosan hydrogels under microwave irradiation, is described. Their chemical and morphological structure, swelling properties, sorption capability of a model dye and cadmium ions are described, and kinetic studies, were carried out. Biodegradability of the obtained hydrogels was investigated with the Sturm Test method. As a result, multifunctional chitosan hydrogels with both negative and positive surface charges and increased ability of anions and cations binding, were obtained. Materials were fully biodegradable, capable to absorb high amounts of water, as well as to remove various water contaminants.Web of Science111081980

Hybrid bilayer PLA/chitosan nanofibrous scaffolds doped with ZnO, Fe3O4, and Au nanoparticles with bioactive properties for skin tissue engineering

Burns affect almost half a million of Americans annually. In the case of full-thickness skin injuries, treatment requires a transplant. The development of bioactive materials that promote damaged tissue regeneration constitutes a great alternative to autografts. For this reason, special attention is focused on three-dimensional scaffolds that are non-toxic to skin cells and can mimic the extracellular matrix, which is mainly composed of nanofibrous proteins. Electrospinning, which enables the preparation of nanofibers, is a powerful tool in the field of biomaterials. In this work, novel hybrid poly (lactic acid)/chitosan biomaterials functionalized with three types of nanoparticles (NPs) were successfully developed. ZnO, Fe3O4, and Au NPs were investigated over their morphology by TEM method. The top layer was obtained from PLA nanofibers, while the bottom layer was prepared from acylated chitosan. The layers were studied over their morphology by the SEM method and their chemical structure by FT-IR. To verify their potential in burn wound treatment, the scaffolds' susceptibility to biodegradation as well as moisture permeability were calculated. Also, biomaterials conductivity was determined in terms of electrostimulation. Finally, cytotoxicity tests were carried out by XTT assay and morphology analysis using both fibroblasts cell line and primary cells. The hybrid nanofibrous scaffolds displayed a great potential in tissue engineering.Web of Science121art. no. 15

Chitosan-based carbon quantum dots for biomedical applications: Synthesis and characterization

Rapid development in medicine and pharmacy has created a need for novel biomaterials with advanced properties such as photoluminescence, biocompability and long-term stability. The following research deals with the preparation of novel types of N-doped chitosan-based carbon quantum dots. Nanomaterials were obtained with simultaneous nitrogen-doping using biocompatible amino acids according to Green Chemistry principles. For the carbon quantum dots synthesis chitosan was used as a raw material known for its biocompability. The nanomaterials obtained in the form of lyophilic colloids were characterized by spectroscopic and spectrofluorimetric methods. Their quantum yields were determined. Additionally the cytotoxicity of the prepared bionanomaterials was evaluated by XTT (2,3-Bis-(2-methoxy-4-nitro5-sulfophenyl)-2H-tetrazolium-5-carboxanflide salt) method. Our results confirmed the formation of biocompatible quantum dots with carbon cores exhibiting luminescence in visible range. Performed studies showed that modification with lysine (11.5%) and glutamic acid (7.4%) had a high impact on quantum yield, whereas functionalization with amino acids rich in S and N atoms did not significantly increase in fluorescence properties. XTT assays as well as morphological studies on human dermal fibroblasts confirmed the lack of cytotoxicity of the prepared bionanomaterials. The study shows chitosan-based quantum dots to be promising for biomedical applications such as cell labelling, diagnostics or controlled drug delivery and release systems.Web of Science92art. no. 27

Efficacy and tolerability of oral propafenone versus quinidine in the treatment of recent onset atrial fibrillation: A randomized, prospective study

Background: A prospective, randomized study was conducted to evaluate the efficacy and tolerability of oral propafenone and quinidine for the conversion of paroxysmal atrial fibrillation (AF). Methods: Eighty one consecutive patients (female/male 46/35; mean age 64.0 &#177; 11.6), admitted to hospital with AF lasting no longer than 48 hours, were randomized in terms of their pharmacological therapy. Forty three patients (55%) were randomly assigned to Group I and received propafenone 600 mg orally as the initial therapy, with an additional dose of 300 mg after eight hours, if the sinus rhythm had not been restored by then. Thirty eight patients (45%) (Group II) received 1 mg digoxin IV followed by an oral loading of quinidine (400 mg followed by 200 mg every two hours). Results: The conversion rate assessed after 24 hours was the same in both groups (Gr. I vs. Gr. II: 90.7 vs. 91.4%), with the same number of mild side effects (Gr. I vs. Gr. II: 37.2% vs. 45.7%). No life-threatening adverse events were reported. Propafenone achieved a higher efficacy rate during the first eight hours (83.3 vs. 54.3%; p = 0.01), with a significantly shorter time required to sinus rhythm recovery throughout the study period, with a median time of 165 min (95% confidence interval 120-278) vs. 360 min (95% confidence inerval 298-650; p < 0.05). There was some indication of greater effectiveness of propafenone than quinidine in early sinus rhythm restoration in patients with: no structural heart disease, in those with an AF duration shorter than 12 hours, and in patients with an ejection fraction > 55%. Conclusions: Although both drugs revealed the same effectiveness, the conversion to sinus rhythm in the group treated with propafenone was observed more quickly despite the longer paroxysmal AF episode duration

Does a blanking period after pulmonary vein isolation impact long-term results? Results after 55 months of follow-up

Background: The aims of the study are 1) to assess antiarrhythmic prophylaxis efficacy dur­ing the first 2 months after radiofrequency ablation (ARF) due to AF; 2) to define risk factors for early AF recurrence (EAFR) after ARF; 3) to determine the long-term follow-up results and risk factors for late AF recurrence (LAFR). Methods: A total number of 210 consecutive patients who had undergone ARF due to AF were analyzed. Patients were randomized into three groups: Group 1 (G1), without any anti­arrhythmic drug (AAD); Group 2 (G2), with amiodarone or sotalol; Group 3 (G3), with last ineffective AAD. The study was designed to analyze two periods: short-term observation, the first 2 months after ARF; and at least 2 years of long-term follow-up. Results: After 2 months, clinical data were collected from 171 patients (123 males, mean age of 50.3 years; persistent AF in 19.8%; lone AF in 36.6%). Sinus rhythm (SR) was maintained in 84 (49.1%) patients; 35 (20.4%) patients presented with a single episode of AF, 39 (23%) patients experienced a reduction in number of AF episodes, and 13 (7.5%) patients showed no improvement. No predisposing factor for early recurrence was found. After a mean follow-up of 55 months, clinical data were collected in 137 patients, of which 47 (34%) maintained SR. Those more likely to sustain SR were: males (82.9% vs. 62.2%; p = 0.018), younger patients (44.8 ± 12.7 vs. 52.5 ± 9.9; p = 0.0001), patients with smaller left atrium diameter (4.05 ± ± 0.49 cm vs. 4.25 ± 0.51 cm; p = 0.04), and those without any AF recurrence during the first 2 months after ARF (78.7% vs. 35.6%; p &lt; 0.0001). In the multivariable analysis, the inde­pendent risk factors for LAFR were hypertension (p &lt; 0.001) and persistent AF (p = 0.014). Conclusions: Antiarrhythmic prophylaxis does not affect the number of AF recurrences during the first 2 months after ablation. SR maintenance during a blanking period after AF ablation is a positive prognostic factor in long-term follow-up. Persistent AF and hypertension are independent risk factors for late AF recurrence after pulmonary vein isolation.

3D hierarchical, nanostructured chitosan/PLA/HA scaffolds doped with TiO2/Au/Pt NPs with tunable properties for guided bone tissue engineering

Bone tissue is the second tissue to be replaced. Annually, over four million surgical treatments are performed. Tissue engineering constitutes an alternative to autologous grafts. Its application requires three-dimensional scaffolds, which mimic human body environment. Bone tissue has a highly organized structure and contains mostly inorganic components. The scaffolds of the latest generation should not only be biocompatible but also promote osteoconduction. Poly (lactic acid) nanofibers are commonly used for this purpose; however, they lack bioactivity and do not provide good cell adhesion. Chitosan is a commonly used biopolymer which positively affects osteoblasts' behavior. The aim of this article was to prepare novel hybrid 3D scaffolds containing nanohydroxyapatite capable of cell-response stimulation. The matrixes were successfully obtained by PLA electrospinning and microwave-assisted chitosan crosslinking, followed by doping with three types of metallic nanoparticles (Au, Pt, and TiO2). The products and semi-components were characterized over their physicochemical properties, such as chemical structure, crystallinity, and swelling degree. Nanoparticles' and ready biomaterials' morphologies were investigated by SEM and TEM methods. Finally, the scaffolds were studied over bioactivity on MG-63 and effect on current-stimulated biomineralization. Obtained results confirmed preparation of tunable biomimicking matrixes which may be used as a promising tool for bone-tissue engineering.Web of Science124art. no. 79

Microwave-assisted synthesis and characterization of novel chitosan-based biomaterials for pelvic organ prolapse treatment

Pelvic organ disorders affect up to one in four women in the United States. The prevalence of pelvic organ prolapse (POP) is increasing with each year, particularly in the setting of prolonged life expectancy and an aging population. Current treatment approaches, including polypropylene monofilaments are associated with numerous painful and worrisome side-effects. Therefore, scientists are looking for new solutions. A promising alternative to the current treatment is tissue engineering, which can be utilized to re-create support to the vagina and pelvic organs. Tissue engineering requires the use of three-dimensional scaffolds, derived from biocompatible materials. Chitosan is a natural polymer, obtained from shellfish exoskeletons. It is known for its biodegradability, lack of cytotoxicity and non-pyrogenicity. Due to the presence of free hydroxyl and amino groups, it may undergo various modifications. In this paper, we describe a new type of chitosan-based biomaterials, which can be used as a new alternative scaffold that may provide support to prolapse organs. The chitosan scaffold was obtained under microwave radiation using multifunctional amino and organic acids. We discuss the scaffold's characteristics, with an emphasis on its chemical structure and morphology. Fourier transform infrared spectroscopy (FT-IR) analysis confirmed cross-linking processes with preservation of free amino groups. Moreover, mechanical durability, the stability and swelling ability of the scaffolds in a simulated body fluid were investigated. All of the prepared scaffolds demonstrated very good antioxidant activity and biodegradability. Importantly, the biocompatibility of chitosan scaffolds was examined on human vaginal VK2/E6E7 cell line. No evidence of toxicity was documented, and the cells maintained their presence on the studied materials. These results allude to the lack of toxicity of the scaffolds, and indicate that chitosan-based scaffold should be further investigated in in vivo studies as they may be a promising alternative treatment to pelvic organ prolapse.Web of Science70349147

Skuteczność i bezpieczeństwo doustnego propafenonu versus chinidyny w przywracaniu rytmu zatokowego u chorych z napadem migotania przedsionków - prospektywne badanie randomizowane

Wstęp: Prospektywne badanie randomizowane przeprowadzono w celu oceny efektywności i tolerancji doustnego propafenonu i chinidyny w leczeniu napadowego migotania przedsionków (AF). Metody: Do badania zakwalifikowano w zależności od leczenia farmakologicznego 81 kolejnych pacjentów (kobiety/mężczyźni 46/35; mediana wieku 64,0 &#177; 11,6 roku), przyjętych do szpitala z AF trwającym nie dłużej niż 48 godzin. Grupę I stanowiło 43 pacjentów (55%), którzy otrzymali doustnie 600 mg propafenonu jako dawkę inicjującą w skojarzeniu z dodatkową dawką 300 mg leku po 8 godzinach, zastosowaną w przypadku, gdy rytm zatokowy nie został do tego czasu przywrócony. Grupa II liczyła 38 pacjentów (45%), którzy otrzymali 1 mg digoksyny dożylnie, a nastepnie chinidynę doustnie (400 mg, potem 200 mg co 2 h). Wyniki: Częstość przywrócenia rytmu zatokowego po 24 godzinach była taka sama w obu grupach (grupa I v. grupa II: 90,1% v. 91,4%; p = 0,78). Nie stwierdzono żadnych zagrażających życiu objawów niepożądanych. Propafenon był bardziej efektywny podczas pierwszych 8 godzin badania (83,3% v. 54,3%; p < 0,01) i wymagał istotnie statystycznie krótszego czasu do przywrócenia rytmu zatokowego z medianą 165 min (95% CI: 120-278 min) v. 360 min (95% CI: 298-650 min; p < 0,05). Również propafenon wykazał lepszą efektywność niż chinidyna w przywróceniu rytmu zatokowego u pacjentów bez zmian strukturalnych mięśnia sercowego, u chorych z AF trwającym krócej niż 12 godzin oraz u pacjentów z frakcją wyrzutową poniżej 55%. Wnioski: Chociaż efektywność obu leków była podobna, propafenon umożliwił szybsze przywrócenie rytmu zatokowego mimo dłużej trwającego epizodu napadowego AF

The potential of novel chitosan-based scaffolds in pelvic organ prolapse (POP) treatment through tissue engineering

The growing number of female reproductive system disorders creates a need for novel treatment methods. Tissue engineering brings hope for patients, which enables damaged tissue reconstruction. For this purpose, epithelial cells are cultured on three-dimensional scaffolds. One of the most promising materials is chitosan, which is known for its biocompatibility and biodegradability. The aim of the following study was to verify the potential of chitosan-based biomaterials for pelvic organ prolapse regeneration. The scaffolds were obtained under microwave-assisted conditions in crosslinking reactions, using dicarboxylic acids and aminoacid as crosslinkers, includingl-glutamic acid, adipic acid, malonic acid, and levulinic acid. The products were characterized over their physicochemical and biological properties. FT-IR analysis confirmed formation of amide bonds. The scaffolds had a highly porous structure, which was confirmed by SEM analysis. Their porosity was above 90%. The biomaterials had excellent swelling abilities and very good antioxidant properties. The cytotoxicity study was performed on vaginal epithelial VK2/E6E7 and human colon cancer HCT116 cell lines. The results showed that after certain modifications, the proposed scaffolds could be used in pelvic organ prolapse (POP) treatment.Web of Science2518art. no. 428