Macrofungal diversity of greenhouses at the Warsaw University Botanic Garden

In 2019–2020 (for 13 months), 21 macrofungi species, both native (14) and inadvertently introduced from warmer regions (7), were found in greenhouses at the Warsaw University Botanic Garden. These included 13 species recorded for the first time in Polish greenhouses. Descriptions and photographs are given for 5 species identified, which are new to Poland (Gymnopus luxurians, Hemimycena ignobilis, Leucoagaricus meleagris, L. rubrotinctus, and Xylaria arbuscula s.l.). The highest variety of species was found in the greenhouses with the collection of tropical and succulents and cacti, with 11 and 8 species, respectively. The number of species ranged from five to four in other greenhouses. The current results increase the number of species reported from greenhouses in Poland to approximately 50. None of the identified species has a negative impact on the growth and health of plants in the greenhouses at the Warsaw University Botanic Garden and at present none of them are indicated as potentially invasive

Environmental Aspects of the Use of CNG in Public Urban Transport

This chapter concerns the problem of assessing the exhaust emission from the engines of city transport buses fuelled by CNG. It presents a comparative analysis of toxic exhaust emissions of CO, HC, NOx and PM, from urban buses powered by diesel and CNG. The measurements were carried out over the SORT standardised cycles as well as during a real drive condition on a city bus route. The research revealed that CNG bus generates significantly lower NOx emission, whereas its CO and HC emissions are higher. Taking into account low PM emissions, CNG buses should be regarded as eco-friendly means of public transport

Fabrication of Plga/Hap and Plga/Phb/Hap Fibrous Nanocomposite Materials for Osseous Tissue Regeneration

The study presents the manufacturing of nanofibrous structures as osteoconductive, osteoinductive materials for osseous tissue regeneration. The fibrous structures were obtained by electrospinning of poly(l-lactide-coglicolide) (PLGA) with addition of hydroxyapatite (HAp) and of a blend of PLGA with polyhydroxybutyrate with HAp added. The polymers used in the experiment were synthesised by an innovative method with a zirconium catalyst. First, the optimal electrospinning process parameters were selected. For the characterisation of the obtained osseous tissue reconstruction materials, the physical, macroscopic, functional, mechanical and thermal properties as well as crystallinity index were studied. The study of the radiation sterilisation influence on average molar mass, thermal and mechanical properties was made in order to analyse the degradation effect

Surface-modified poly(l-lactide-co-glycolide) scaffolds for the treatment of osteochondral critical size defects : in vivo studies on rabbits

Poly(l-lactide-co-glycolide) (PLGA) porous scaffolds were modified with collagen type I (PLGA/coll) or hydroxyapatite (PLGA/HAp) and implanted in rabbits osteochondral defects to check their biocompatibility and bone tissue regeneration potential. The scaffolds were fabricated using solvent casting/particulate leaching method. Their total porosity was 85% and the pore size was in the range of 250–320 µm. The physico-chemical properties of the scaffolds were evaluated using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffractometry (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), sessile drop, and compression tests. Three types of the scaffolds (unmodified PLGA, PLGA/coll, and PLGA/HAp) were implanted into the defects created in New Zealand rabbit femoral trochlears; empty defect acted as control. Samples were extracted after 1, 4, 12, and 26 weeks from the implantation, evaluated using micro-computed tomography (µCT), and stained by Masson–Goldner and hematoxylin-eosin. The results showed that the proposed method is suitable for fabrication of highly porous PLGA scaffolds. Effective deposition of both coll and HAp was confirmed on all surfaces of the pores through the entire scaffold volume. In the in vivo model, PLGA and PLGA/HAp scaffolds enhanced tissue ingrowth as shown by histological and morphometric analyses. Bone formation was the highest for PLGA/HAp scaffolds as evidenced by µCT. Neo-tissue formation in the defect site was well correlated with degradation kinetics of the scaffold material. Interestingly, around PLGA/coll extensive inflammation and inhibited tissue healing were detected, presumably due to immunological response of the host towards collagen of bovine origin. To summarize, PLGA scaffolds modified with HAp are the most promising materials for bone tissue regeneration

Elaboration and characterization of biodegradable scaffolds from poly (L-Lactide-co-glycolide) synthesized with low-toxic zirconium acetylacetonate

Objectives: The aim of the study was to answer the questions whether poly (L-lactide-co-glycolide) synthesized with the use of zirconium acetylacetonate: (i) is less toxic in vitro than that synthesized with tin compound; (ii) is it possible to produce scaffolds from such copolymer, and (iii) how these scaffolds degrade in vitro. Methods: A human osteoblast line (Saos2) was used to verify the biocompatibility of the copolymer. Porous scaffolds were obtained via the solvent casting / particulate leaching technique. The scaffolds were characterized in terms of surface chemistry (FTIR-ATR, contact angle), microstructure (porosity, water uptake, SEM) and degradation in PBS (GPC, SEM, FTIR-ATR, mass loss). Results: The copolymer synthesized with the zirconium compound performs better in contact with osteoblasts in vitro than that synthesized with tin. Porous scaffolds from a such copolymer can be easily prepared by the solvent casting/salt leaching technique. These scaffolds, having a high open porosity (88% ± 2%) and water uptake of (630% ± 50%) maintain their dimensions and porous microstructure for 8 weeks in PBS. The scaffolds degrade in vitro, but the rate of degradation is quite low. Conclusion: The results of biological, textural, and physico-chemical properties of obtained porous material, regarding its behaviour in conditions simulating biological environment, show that it could be used as a scaffold for bone tissue engineering

Manufacturing and characterization of resorbable PLGA membranes for biomedical applications

Porous poly(L-lactide-co-glycolide) (PLGA) membranes were prepared by solvent-casting/porogen leaching method. Poly(ethylene-glycol) (PEG) with two molecular weights was used as a pore former. Mechanical properties of the membranes were analyzed in tensile test. Topography, pore size and surface roughness were characterized by atomic force microscopy on both sites of the membranes. PEG leached out percentage, thickness and wettability were also measured. Osteoblast-like cells were cultured on the membranes for 24 h and 6 days, and morphology, distribution and number of adhered cells as well as secretion of proteins and nitric oxide were measured. The results show that PEG molecular weight affected size and distribution of pores on both surfaces of the membranes. It resulted also in different mechanical characteristics of the membranes. In vitro experiments show that the membranes support adhesion and growth of osteoblast-like cells suggesting their usefulness for guided tissue regeneration (GTR)

Bioresorbable porous poly-(glycolide-co-L-lactide) scaffolds for tissue engineering : the influence of microstructure on osteoblasts in vitro

Opracowano trzy rodzaje bioresorbowalnych gąbek dla inżynierii tkankowej. Gąbki te miały taką samą chemiczną budowę powierzchni i udziai objętościowy porów, ale różny rozmiar porów: około 600 r/m, 200pm i 40pm. Badania komórkowe (przeżywalność, synteza kolagenu) wykazały, że gąbka o największym rozmiarze porów jest najkorzystniejsza dla hodowli osteoblastów in vitro.Three types of bioresorbable foams for bone tissue engineering proposes have been elaborated. The foams have identical surface chemistry and volume fraction of pores but different pore sizes: about 600pm, 200 pm and 40 pm, respectively. The results of in vitro osteoblasts study (viability and collagen synthesis) indicate that the best is the foam having the biggest size ofpores

The influence of paclitaxel on hydrolytic degradation in matrices obtained from aliphatic polyesters and polyester carbonates

Biodegradable polymers have become common materials used in pharmacy and medicine due to their properties such as mechanical strength, biocompatibility and non-toxic degradation products. Different compositions of copolymers and also their chain microstructure may have an effect on matrices degradation and thus on the drug release profile. In our study, we aimed at the influence of paclitaxel content on hydrolytic degradation process of terpolymeric matrices. Hydrolytic degradation of three kinds of matrices (with 5 or 10% of paclitaxel and drug free matrices) prepared from three types of terpolymers was performed in vitro at 37OC in phosphate buffer solution (PBS, pH 7,4). The 1H and 13C NMR spectra of terpolymers were recorded. Thermal properties were monitored by differential scanning calorimetry (DSC). Molecular weight dispersity (D) and molecular weight were determined using gel permeation chromatography (GPC). The surface morphology was studied by means of the scanning electron microscopy (SEM). The most significant degradation was observed in case of poly(L-lactide-co-glycolide-co-ε-caprolactone) 44:32:24. Weight loss and water uptake were similar in the event of the same type of matrices obtained from the two poly(L-lactide-co-glycolide-co-TMC). Decelerated paclitaxel release in case of matrices with 51:26:23 molar ratio was noticed and it can be connected with higher content of carbonate units. Knowledge of paclitaxel influence on hydrolytic degradation process may contribute to receive valuable information about its release mechanisms from biodegradable terpolymers

Thermographic evaluation of the sinus areas of selected groups of students - pilot study

Thermal imaging technique is a sufficiently precise tool by which you can evaluate the condition of the blood supply of various areas of the body. Blood supply is connected with physiological functional status or ongoing pathological processes such as inflammation. The study was conducted on 40 volunteers - randomly selected students. The results are characterized by a slight standard deviation in maximum and minimum temperatures in the maxillary sinus area and the minimal difference between these results. On the basis of studies, the range of values of the reference temperature of the maxillary sinus. This range was isolated based on the results of a group of 39 individuals. It has been shown that in case of one person the results were not within the range of reference values indicating the presence of chronic inflammatory sinusitis