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1.
Int J Mol Sci ; 25(17)2024 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-39273135

RESUMO

The endocannabinoid system (ECS) plays a crucial role in reproductive health, but its function in postpartum dairy cows remains poorly understood. This study investigated the expression patterns of ECS-related genes in the endometrium of postpartum dairy cows and their associations with endometrial health and the presence of fatty liver. Endometrial biopsies were collected from 22 Holstein Friesian cows at 4 and 7 weeks postpartum. Gene expression was analyzed using RT-qPCR, focusing on key ECS components including CNR2, MGLL, FAAH1, NAAA, NAPEPLD, PADI4 and PTGDS. The results reveal dynamic changes in ECS gene expression associated with endometritis and fatty liver. MGLL expression was significantly upregulated in cows with endometritis at 7 weeks postpartum, while NAAA expression was consistently downregulated in cows with fatty liver. CNR2 showed a time-dependent pattern in endometritis, and PTGDS expression was elevated in clinical endometritis at 4 weeks postpartum. The presence of fatty liver was associated with altered expression patterns of several ECS genes, suggesting a link between metabolic stress and endometrial ECS function. These findings indicate a potential role for the ECS in postpartum uterine health and recovery, offering new insights into the molecular mechanisms underlying reproductive disorders in dairy cows and paving the way for novel therapeutic approaches.


Assuntos
Doenças dos Bovinos , Endocanabinoides , Endométrio , Fígado Gorduroso , Período Pós-Parto , Animais , Feminino , Bovinos , Endométrio/metabolismo , Endométrio/patologia , Endocanabinoides/metabolismo , Endocanabinoides/genética , Fígado Gorduroso/genética , Fígado Gorduroso/veterinária , Fígado Gorduroso/metabolismo , Período Pós-Parto/genética , Período Pós-Parto/metabolismo , Doenças dos Bovinos/genética , Doenças dos Bovinos/metabolismo , Endometrite/veterinária , Endometrite/genética , Endometrite/metabolismo , Regulação da Expressão Gênica
2.
Polymers (Basel) ; 16(18)2024 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-39339144

RESUMO

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.

3.
ACS Appl Bio Mater ; 7(7): 4293-4306, 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-38917363

RESUMO

The present work aims to develop optimized scaffolds for bone repair by incorporating mesoporous nanoparticles into them, thereby combining bioactive factors for cell growth and preventing rapid release or loss of effectiveness. We synthesized biocompatible and biodegradable scaffolds designed for the controlled codelivery of curcumin (CUR) and recombinant human bone morphogenic protein-2 (rhBMP-2). Active agents in dendritic silica/titania mesoporous nanoparticles (DSTNs) were incorporated at different weight percentages (0, 2, 5, 7, 9, and 10 wt %) into a matrix of polycaprolactone (PCL) and polyethylene glycol (PEG) nanofibers, forming the CUR-BMP-2@DSTNs/PCL-PEG delivery system (S0, S2, S5, S7, S9, and S10, respectively, with the number showing the weight percentage). To enhance the formation process, the system was treated using low-intensity pulsed ultrasound (LIPUS). Different advanced methods were employed to assess the physical, chemical, and mechanical characteristics of the fabricated scaffolds, all confirming that incorporating the nanoparticles improves their mechanical and structural properties. Their hydrophilicity increased by approximately 25%, leading to ca. 53% enhancement in their water absorption capacity. Furthermore, we observed a sustained release of approximately 97% for CUR and 70% for BMP-2 for the S7 (scaffold with 7 wt % DSTNs) over 28 days, which was further enhanced using ultrasound. In vitro studies demonstrated accelerated scaffold biodegradation, with the highest level observed in S7 scaffolds, approximately three times higher than the control group. Moreover, the cell viability and proliferation on DSTNs-containing scaffolds increased when compared to the control group. Overall, our study presents a promising nanocomposite scaffold design with notable improvements in structural, mechanical, and biological properties compared to the control group, along with controlled and sustained drug release capabilities. This makes the scaffold a compelling candidate for advanced bone tissue engineering and regenerative therapies.


Assuntos
Materiais Biocompatíveis , Proteína Morfogenética Óssea 2 , Teste de Materiais , Nanofibras , Osteogênese , Tamanho da Partícula , Osteogênese/efeitos dos fármacos , Nanofibras/química , Proteína Morfogenética Óssea 2/química , Humanos , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Ondas Ultrassônicas , Curcumina/química , Curcumina/farmacologia , Proliferação de Células/efeitos dos fármacos , Proteínas Recombinantes/química , Proteínas Recombinantes/farmacologia , Proteínas Recombinantes/administração & dosagem , Sobrevivência Celular/efeitos dos fármacos , Poliésteres/química , Polímeros/química , Alicerces Teciduais/química , Polietilenoglicóis/química , Fator de Crescimento Transformador beta
4.
Acta Biomater ; 176: 417-431, 2024 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-38272200

RESUMO

Human mesenchymal stromal cells (hMSCs) seeded on calcium phosphate (CaP) bioceramics are extensively explored in bone tissue engineering and have recently shown effective clinical outcomes. In previous pre-clinical studies, hMSCs-CaP-mediated bone formation was preceded by osteoclastogenesis at the implantation site. The current study evaluates to what extent phase composition of CaPs affects the osteoclast response and ultimately influence bone formation. To this end, four different CaP bioceramics were used, hydroxyapatite (HA), ß-tricalcium phosphate (ß-TCP) and two biphasic composites of HA/ß-TCP ratios of 60/40 and 20/80 respectively, for in vitro osteoclast differentiation and correlation with in vivo osteoclastogenesis and bone formation. All ceramics allowed osteoclast formation in vitro from mouse and human precursors, except for pure HA, which significantly impaired their maturation. Ectopic implantation alongside hMSCs in subcutis sites of nude mice revealed new bone formation at 8 weeks in all conditions with relative amounts for ß-TCP > biphasic CaPs > HA. Surprisingly, while hMSCs were essential for osteoinduction, their survival did not correlate with bone formation. By contrast, the degree of early osteoclastogenesis (2 weeks) seemed to define the extent of subsequent bone formation. Together, our findings suggest that the osteoclastic response could be used as a predictive marker in hMSC-CaP-based bone regeneration and strengthens the need to understand the underlying mechanisms for future biomaterial development. STATEMENT OF SIGNIFICANCE: The combination of mesenchymal stromal cells (MSCs) and calcium phosphate (CaP) materials has demonstrated its safety and efficacy for bone regeneration in clinical trials, despite our insufficient understanding of the underlying biological mechanisms. Osteoclasts were previously suggested as key mediators between the early inflammatory phase following biomaterial implantation and the subsequent bone formation. Here we compared the affinity of osteoclasts for various CaP materials with different ratios of hydroxyapatite to ß-tricalcium phosphate. We found that osteoclast formation, both in vitro and at early stages in vivo, correlates with bone formation when the materials were implanted alongside MSCs in mice. Surprisingly, MSC survival did not correlate with bone formation, suggesting that the number or phenotype of osteoclasts formed was more important.


Assuntos
Fosfatos de Cálcio , Osteogênese , Animais , Humanos , Camundongos , Camundongos Nus , Fosfatos de Cálcio/farmacologia , Materiais Biocompatíveis/farmacologia , Durapatita/farmacologia , Hidroxiapatitas/farmacologia , Cerâmica
5.
Adv Mater ; 36(6): e2307639, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38009631

RESUMO

Treating bone infections and ensuring bone repair is one of the greatest global challenges of modern orthopedics, made complex by antimicrobial resistance (AMR) risks due to long-term antibiotic treatment and debilitating large bone defects following infected tissue removal. An ideal multi-faceted solution would will eradicate bacterial infection without long-term antibiotic use, simultaneously stimulating osteogenesis and angiogenesis. Here, a multifunctional collagen-based scaffold that addresses these needs by leveraging the potential of antibiotic-free antimicrobial nanoparticles (copper-doped bioactive glass, CuBG) to combat infection without contributing to AMR in conjunction with microRNA-based gene therapy (utilizing an inhibitor of microRNA-138) to stimulate both osteogenesis and angiogenesis, is developed. CuBG scaffolds reduce the attachment of gram-positive bacteria by over 80%, showcasing antimicrobial functionality. The antagomiR-138 nanoparticles induce osteogenesis of human mesenchymal stem cells in vitro and heal a large load-bearing defect in a rat femur when delivered on the scaffold. Combining both promising technologies results in a multifunctional antagomiR-138-activated CuBG scaffold inducing hMSC-mediated osteogenesis and stimulating vasculogenesis in an in vivo chick chorioallantoic membrane model. Overall, this multifunctional scaffold catalyzes killing mechanisms in bacteria while inducing bone repair through osteogenic and angiogenic coupling, making this platform a promising multi-functional strategy for treating and repairing complex bone infections.


Assuntos
MicroRNAs , Nanopartículas , Humanos , Ratos , Animais , Alicerces Teciduais , Regeneração Óssea , MicroRNAs/genética , Antagomirs/farmacologia , Osteogênese , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico
6.
Biomaterials ; 303: 122398, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37979514

RESUMO

Very large bone defects significantly diminish the vascular, blood, and nutrient supply to the injured site, reducing the bone's ability to self-regenerate and complicating treatment. Delivering nanomedicines from biomaterial scaffolds that induce host cells to produce bone-healing proteins is emerging as an appealing solution for treating these challenging defects. In this context, microRNA-26a mimics (miR-26a) are particularly interesting as they target the two most relevant processes in bone regeneration-angiogenesis and osteogenesis. However, the main limitation of microRNAs is their poor stability and issues with cytosolic delivery. Thus, utilising a collagen-nanohydroxyapatite (coll-nHA) scaffold in combination with cell-penetrating peptide (RALA) nanoparticles, we aimed to develop an effective system to deliver miR-26a nanoparticles to regenerate bone defects in vivo. The microRNA-26a complexed RALA nanoparticles, which showed the highest transfection efficiency, were incorporated into collagen-nanohydroxyapatite scaffolds and in vitro assessment demonstrated the miR-26a-activated scaffolds effectively transfected human mesenchymal stem cells (hMSCs) resulting in enhanced production of vascular endothelial growth factor, increased alkaline phosphatase activity, and greater mineralisation. After implantation in critical-sized rat calvarial defects, micro CT and histomorphological analysis revealed that the miR-26a-activated scaffolds improved bone repair in vivo, producing new bone of superior quality, which was highly mineralised and vascularised compared to a miR-free scaffold. This innovative combination of osteogenic collagen-nanohydroxyapatite scaffolds with multifunctional microRNA-26a complexed nanoparticles provides an effective carrier delivering nanoparticles locally with high efficacy and minimal off-target effects and demonstrates the potential of targeting osteogenic-angiogenic coupling using scaffold-based nanomedicine delivery as a new "off-the-shelf" product capable of healing complex bone injuries.


Assuntos
MicroRNAs , Osteogênese , Animais , Humanos , Ratos , Regeneração Óssea , Diferenciação Celular , Colágeno , MicroRNAs/genética , MicroRNAs/metabolismo , Alicerces Teciduais , Fator A de Crescimento do Endotélio Vascular/metabolismo
7.
Polymers (Basel) ; 15(17)2023 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-37688155

RESUMO

The management of by-products and waste from agriculture and the agri-food industry is a challenge for the plastics industry. Flexible polyurethane foams (EPPUR) containing ground corncake from corn oil production were obtained. The influence of the bio-filler on the physico-mechanical and thermal properties of synthesized flexible polyurethane foams was investigated. The content of corncake ranged from 0 php (part per 100 parts of polyol) to 10 php. Open-cell flexible polyurethane foams with a favorable comfort factor were obtained. The lower reactivity of the developed polyurethane systems was conducive to the formation of cells of slightly smaller sizes but of a more regular shape in comparison with the foam not modified with the bio-filler. Measurements of the mechanical properties indicated that the modified foams held had similar or even better properties than the reference sample without bio-filler.

8.
Materials (Basel) ; 16(9)2023 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-37176283

RESUMO

The article compares the properties of bio-polyols obtained from white mustard (Sinapis alba) seed oil, which contain boron and sulfur atoms. Each of the bio-polyols was prepared by a different method of testing the efficiency of the incorporation of boron and sulfur atoms. All synthesis methods were based on the epoxidation of unsaturated bonds followed by the opening of epoxy rings by compounds containing heteroatoms. Two of the bio-polyols were subjected to additional esterification reactions of hydroxyl groups with boric acid or its ester. Three new bio-polyols were obtained as a result of the performed syntheses. The synthesized compounds were subjected to detailed physicochemical (physical state, color, smell, density, viscosity and pH), analytical (hydroxyl number, acid number, water content, content of C, H, N, S, O, B elements and GPC analysis), spectroscopic (FTIR, 1H NMR and 13C NMR) and thermal (DSC) tests. The obtained results allowed for a detailed characterization of the synthesized bio-polyol raw materials. Their suitability for obtaining polyurethane materials was also determined. The synthesized compounds have been found to be an interesting alternative to petrochemical polyols. The influence of the synthesized compounds on the flammability of polyurethane materials was tested experimentally. On the basis of this testing, a number of rigid polyurethane/polyisocyanurate foams were obtained, which were then subjected to flammability tests with the methods of horizontal and vertical burning, limiting oxygen index (LOI) and using the cone calorimeter. Based on this research, it was found that the presence of sulfur and boron heteroatoms reduced the flammability of polyurethane materials based on synthesized bio-polyols.

9.
Nutrients ; 15(8)2023 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-37111089

RESUMO

This study aimed at finding whether healthy eating habits could be introduced to and maintained by chronically mentally ill permanent residents of a nursing home. Of interest was also if the effects of the dietary intervention would be observable as improved carbohydrate and lipid metabolism indicators were selected. Assays covered 30 antipsychotics-treated residents diagnosed with schizophrenia. The prospective method applied involved questionnaires, nutrition-related interviews, anthropometric measurements, and determination of selected biochemical parameters of the blood. The dietary intervention as well as the parallel health-promoting nutrition-related education was aimed at balancing the energy and nutrient contents. Schizophrenia patients were shown to be capable of accepting and observing the principles of appropriate nutrition. The intervention was strong enough to result in a significant blood glucose concentration drop to the reference level in all patients, regardless of the antipsychotic they were treated with. The blood lipid levels also improved, but the reduction in triacylglycerols, total cholesterol and LDL-cholesterol levels was significant in the male patients only. Nutritional changes were reflected in overweight and obese women only, in body weight reduction and in waist adipose tissue loss.


Assuntos
Antipsicóticos , Esquizofrenia , Humanos , Masculino , Feminino , Antipsicóticos/uso terapêutico , Esquizofrenia/tratamento farmacológico , Metabolismo dos Lipídeos , Dieta , Peso Corporal , Carboidratos , Colesterol , Índice de Massa Corporal
10.
Acta Biomater ; 156: 61-74, 2023 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-35907556

RESUMO

Damaged or diseased bone can be treated using autografts or a range of different bone grafting biomaterials, however limitations with such approaches has motivated increased interest in developmentally inspired bone tissue engineering (BTE) strategies that seek to recapitulate the process of endochondral ossification (EO) as a means of regenerating critically sized defects. The clinical translation of such strategies will require the engineering of scaled-up, geometrically defined hypertrophic cartilage grafts that can be rapidly vascularised and remodelled into bone in mechanically challenging defect environments. The goal of this study was to 3D bioprint mechanically reinforced cartilaginous templates and to assess their capacity to regenerate critically sized femoral bone defects. Human mesenchymal stem/stromal cells (hMSCs) were incorporated into fibrin based bioinks and bioprinted into polycaprolactone (PCL) frameworks to produce mechanically reinforced constructs. Chondrogenic priming of such hMSC laden constructs was required to support robust vascularisation and graft mineralisation in vivo following their subcutaneous implantation into nude mice. With a view towards maximising their potential to support endochondral bone regeneration, we next explored different in vitro culture regimes to produce chondrogenic and early hypertrophic engineered grafts. Following their implantation into femoral bone defects within transiently immunosuppressed rats, such bioprinted constructs were rapidly remodelled into bone in vivo, with early hypertrophic constructs supporting higher levels of vascularisation and bone formation compared to the chondrogenic constructs. Such early hypertrophic bioprinted constructs also supported higher levels of vascularisation and spatially distinct patterns of new formation compared to BMP-2 loaded collagen scaffolds (here used as a positive control). In conclusion, this study demonstrates that fibrin based bioinks support chondrogenesis of hMSCs in vitro, which enables the bioprinting of mechanically reinforced hypertrophic cartilaginous templates capable of supporting large bone defect regeneration. These results support the use of 3D bioprinting as a strategy to scale-up the engineering of developmentally inspired templates for BTE. STATEMENT OF SIGNIFICANCE: Despite the promise of developmentally inspired tissue engineering strategies for bone regeneration, there are still challenges that need to be addressed to enable clinical translation. This work reports the development and assessment (in vitro and in vivo) of a 3D bioprinting strategy to engineer mechanically-reinforced cartilaginous templates for large bone defect regeneration using human MSCs. Using distinct in vitro priming protocols, it was possible to generate cartilage grafts with altered phenotypes. More hypertrophic grafts, engineered in vitro using TGF-ß3 and BMP-2, supported higher levels of blood vessel infiltration and accelerated bone regeneration in vivo. This study also identifies some of the advantages and disadvantages of such endochondral bone TE strategies over the direct delivery of BMP-2 from collagen-based scaffolds.


Assuntos
Bioimpressão , Células-Tronco Mesenquimais , Camundongos , Ratos , Humanos , Animais , Camundongos Nus , Cartilagem , Engenharia Tecidual/métodos , Colágeno , Alicerces Teciduais , Condrogênese/genética
12.
Rocz Panstw Zakl Hig ; 73(4): 387-402, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36546865

RESUMO

The Position Statement on the principles of nutrition for children aged 1-3 years emphasizes that proper nutrition of children at this age determines their optimal psychometric development and has beneficial effects on the process nutritional programming, which reduces the risk of diet-related diseases in adulthood. Continued breastfeeding in the post-infancy period, together with the proper introduction of complementary foods, supplies all the nutritional needs of the child. A varied selection of food products is important to balance out the diet of a child in the context of energy and nutrient needs. Attention should be paid to products not recommended for frequent consumption, due to the possibility of the early development of improper eating habits that can lead to undesirable health consequences. Due to the potential risk of deficiency, adequate intake of iron, iodine, calcium and vitamin D, as well as of n-3 PUFAs (which is often insufficient) should be provided. Adequate dietary energy and protein intake protects children against protein-energy undernutrition and is crucial for their proper growth and development. An important element in the assessment of the development of children involves monitoring their nutritional status and physical development by systematically measuring their body weight and length/height and analyzing their weight gain. It is necessary to diagnose the causes of being underweight/overweight in children. Physical activity (such as outdoor walks, plays, and games) and healthy sleep hygiene are recommended. Physical activity, an adequate number of hours of sleep, and the quality of sleep in early childhood may improve immunity, reduce the risk of excessive weight gain, and consequently reduce the risk of obesity later in life. Other issues discussed include the functioning of the digestive system as one of the determinants of the nutrition of young children, basics of proper nutrition, risk of nutrient deficiencies and development of proper eating habits in early childhood.


Assuntos
Ciências da Nutrição , Estado Nutricional , Feminino , Humanos , Criança , Pré-Escolar , Adulto , Polônia , Dieta , Aumento de Peso
13.
Nutrients ; 14(20)2022 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-36297033

RESUMO

Relationships between diet, sex hormone concentrations, and the estrous cycle are important from the perspective of infertility and estrogen-dependent disease prevention and treatment. Four dietary interventions reflecting modern eating behaviors were explored. The study involved 50 female rats divided into five feeding groups. The impact of the amount of sucrose consumed (9% and 18% of the dietary energy content), alternating high-sucrose and sucrose-free diets, and a high-sucrose diet combined with intermittent one-day fasting on the estrous cycle and sex hormone concentrations in female rats was assessed. Even low amounts of dietary sucrose (9% of the dietary energy content) were found to lead to increased estradiol (E2) concentrations and decreased progesterone (Pg) concentrations. A high-sucrose diet, even when periodically applied, additionally led to a reduced concentration of luteinizing hormone (LH). The largest changes in the hormones tested were observed with one-day fasting coupled with the high-sucrose diet; in addition, the estrous phase was shortened and the estrous cycle was disrupted. The results of this study show that both the amount of dietary sucrose and also its uptake pattern affect the estrous cycle and sex hormone concentrations in female rats.


Assuntos
Jejum , Progesterona , Animais , Feminino , Ratos , Sacarose Alimentar , Hormônio Luteinizante , Ciclo Estral , Estradiol , Hormônios Esteroides Gonadais , Estrogênios , Dieta
14.
Biomater Adv ; 136: 212797, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35929296

RESUMO

Since the discovery that nanostructured surfaces were able to kill bacteria, many works have been published focusing on the design of nanopatterned surfaces with antimicrobial properties. Synthetic bone grafts, based on calcium phosphate (CaP) formulations, can greatly benefit from this discovery if adequate nanotopographies can be developed. However, CaP are reactive materials and experience ionic exchanges when placed into aqueous solutions which may in turn affect cell behaviour and complicate the interpretation of the bactericidal results. The present study explores the bactericidal potential of two nanopillared CaP prepared by hydrolysis of two different sizes of α-tricalcium phosphate (α-TCP) powders under biomimetic or hydrothermal conditions. A more lethal bactericidal response toward Pseudomonas aeruginosa (~75% killing efficiency of adhered bacteria) was obtained from the hydrothermally treated CaP which consisted in a more irregular topography in terms of pillar size (radius: 20-60 nm), interpillar distances (100-1500 nm) and pillar distribution (pillar groups forming bouquets) than the biomimetically treated one (radius: 20-40 nm and interpillar distances: 50-200 nm with a homogeneous pillar distribution). The material reactivity was greatly influenced by the type of medium (nutrient-rich versus nutrient-free) and the presence or not of bacteria. A lower reactivity and superior bacterial attachment were observed in the nutrient-free medium while a lower attachment was observed for the nutrient rich medium which was explained by a superior reactivity of the material paired with the lower tendency of planktonic bacteria to adhere on surfaces in the presence of nutrients. Importantly, the ionic exchanges produced by the presence of materials were not toxic to planktonic cells. Thus, we can conclude that topography was the main contributor to mortality in the bacterial adhesion tests.


Assuntos
Biomimética , Nanoestruturas , Antibacterianos/farmacologia , Aderência Bacteriana , Fosfatos de Cálcio/farmacologia
15.
Int J Mol Sci ; 22(16)2021 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-34445654

RESUMO

Rigid polyurethane/polyisocyanurate (RPU/PIR) foam formulations were modified by evening primrose (Oenothera biennis) oil cake as a bio-filler in the amount of 5 to 50 wt.%. The obtained foams were tested in terms of processing parameters, cellular structure (SEM analysis), physico-mechanical properties (apparent density, compressive strength, brittleness, accelerated aging tests), thermal insulation properties (thermal conductivity coefficient, closed cells content, absorbability and water absorption), flammability, smoke emission, and thermal properties. The obtained results showed that the amount of bio-filler had a significant influence on the morphology of the modified foams. Thorough mixing of the polyurethane premix allowed better homogenization of the bio-filler in the polyurethane matrix, resulting in a regular cellular structure. This resulted in an improvement in the physico-mechanical and thermal insulation properties as well as a reduction in the flammability of the obtained materials. This research provided important information on the management of the waste product from the edible oil industry and the production process of fire-safe RPU/PIR foams with improved performance properties. Due to these beneficial effects, it was found that the use of evening primrose oil cake as a bio-filler for RPU/PIR foams opens a new way of waste management to obtain new "green" materials.


Assuntos
Ácidos Linoleicos/química , Oenothera biennis/química , Óleos de Plantas/química , Polímeros/química , Poliuretanos/química , Triazinas/química , Resíduos/análise , Ácido gama-Linolênico/química
16.
Int J Mol Sci ; 22(16)2021 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-34445688

RESUMO

The aim of the presented research was to obtain two new eco-polyols based on waste polylactide (PLA) and to check the effect on the properties of rigid polyurethane (RPU) foams and, based on these, rigid polyurethane/polyisocyanurate (RPU/PIR) foams. The synthesis of eco-polyols was based on the transesterification reaction of melted PLA with diethylene glycol in the presence of an organometallic catalyst. Properties of the obtained eco-polyols were examined for their potential as raw materials for synthesis of rigid polyurethane and polyisocyanurate foams, i.e., hydroxyl value, acid value, density, viscosity, pH, water content. Spectroscopic studies (FTIR, 1H NMR and 13C NMR) were also carried out. Results of these tests confirmed the assumed chemical structure of the new polyols. RPU and RPU/PIR foam formulations were developed based on the obtained analytical results. Partial replacement of petrochemical polyol by eco-polyols in RPU and RPU/PIR foams decreased the value of apparent density, compressive strength, brittleness and water absorption. Moreover, all foams modified by eco-polyols showed higher resistance to aging. All RPU/PIR foams and most PRU foams modified by eco-polyols from waste PLA had better functional properties than the reference foams based on petrochemical polyol.


Assuntos
Polímeros/química , Poliuretanos/química , Triazinas/química , Catálise , Força Compressiva , Poliésteres/química , Poliuretanos/síntese química , Viscosidade
17.
PLoS One ; 16(5): e0251789, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34003845

RESUMO

The aim of the study was to assess the effect of different models of sucrose intake on carbohydrate-lipid metabolism and changes in oxidant balance in the ovaries and uterus of rats. Animals were divided into three groups: I-basic feed, II-feed contains 8% of sucrose, III-alternately every second week the basic feed and modified feed contains 16% of sucrose. The diet containing 8% of sucrose was found to result in an increased activity of antioxidant enzymes in the blood, with unchanged malonylodialdehyde concentration. Variable sucrose administration pattern intensified oxidative stress in the blood and led to disturbed redox equilibrium in the rat uterus, even at a comparable long-term sucrose uptake as in the group II. This was manifested as a reduced superoxide dismutase activity (in the blood and uterus) and a higher malonylodialdehyde concentration (in the uterus). The changes observed could have been a result of metabolic disorders (higher amount of visceral fat, higher glucose concentration, higher index of homeostasis model assessment of insulin resistance, and reduced HDL-cholesterol concentration) and endocrine disorders (higher oestrogen concentrations). Changes in the antioxidant status in the rats kept on the alternating diet, may underpin the failure of fertilised egg implantation in the uterine tissue and pregnancy completion.


Assuntos
Ração Animal , Sacarose Alimentar , Ovário/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Útero/metabolismo , Animais , Glicemia/metabolismo , Sacarose Alimentar/efeitos adversos , Sacarose Alimentar/farmacologia , Feminino , Resistência à Insulina , Metabolismo dos Lipídeos/efeitos dos fármacos , Oxirredução/efeitos dos fármacos , Ratos , Ratos Wistar
18.
Animals (Basel) ; 11(3)2021 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-33809257

RESUMO

This study aimed at assessing the behaviour of Konik geldings and mares, kept in a stable and in a free-range system, during behavioural tests regarded as a determinant of the exploration urge. A total of 19 Konik horses kept in individual stables and in a free-range system were included in the study. The experiment was conducted in five phases separated by five-day breaks. A one-stage passive human test was performed during the first phase, a three-stage active human test-2nd phase, a three-stage unknown object test-3rd phase, a two-stage unknown surface test-4th phase, and a one-stage test of social isolation-5th phase. Ten attributes were analysed, including the horse sex and the keeping system. The results were also correlated with one another. Konik horses were found to show the urge to explore, although their behavioural responses are individual and stimulus dependent. In many cases, the horse sex and the keeping system influence the exploratory behaviour, although it is manifested by a greater intensity in geldings than in mares, and in free-range horses than in those kept in a stable. The study is regarded as preliminary due to the small number of horses in the study groups.

19.
Mater Sci Eng C Mater Biol Appl ; 120: 111657, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33545824

RESUMO

Core-shell scaffolds offer a promising regenerative solution to debilitating injuries to anterior cruciate ligament (ACL) thanks to a unique biphasic structure. Nevertheless, current core-shell designs are impaired by an imbalance between permeability, biochemical and mechanical cues. This study aimed to address this issue by creating a porous core-shell construct which favors cell infiltration and matrix production, while providing mechanical stability at the site of injury. The developed core-shell scaffold combines an outer shell of electrospun poly(caprolactone) fibers with a freeze-dried core of type I collagen doped with proteoglycans (biglycan, decorin) or glycosaminoglycans (chondroitin sulphate, dermatan sulphate). The aligned fibrous shell achieved an elastic modulus akin of the human ACL, while the porous collagen core is permeable to human mesenchymal stem cell (hMSC). Doping of the core with the aforementioned biomolecules led to structural and mechanical changes in the pore network. Assessment of cellular metabolic activity and scaffold contraction shows that hMSCs actively remodel the matrix at different degrees, depending on the core's doping formulation. Additionally, immunohistochemical staining and mRNA transcript levels show that the collagen-chondroitin sulphate formulation has the highest matrix production activity, while the collagen-decorin formulation featured a matrix production profile more characteristic of the undamaged tissue. Together, this demonstrates that scaffold doping with target biomolecules leads to distinct levels of cell-mediated matrix remodeling. Overall, this work resulted in the development of a versatile and robust platform with a combination of mechanical and biochemical features that have a significant potential in promoting the repair process of ACL tissue.


Assuntos
Glicosaminoglicanos , Alicerces Teciduais , Colágeno , Humanos , Poliésteres , Engenharia Tecidual
20.
Int J Mol Sci ; 22(1)2020 Dec 23.
Artigo em Inglês | MEDLINE | ID: mdl-33374754

RESUMO

Two polyol raw materials were obtained in the conducted research, one based on metasilicic acid (MSA), the other based on poly(lactic acid) (PLA) waste. The obtained polyols were characterized in terms of their applicability for the production of rigid polyurethane foams (RPUFs). Their basic analytical properties (hydroxyl number, acid number, elemental analysis) and physicochemical properties (density, viscosity) were determined. The assumed chemical structure of the obtained new compounds was confirmed by performing FTIR and 1H NMR spectroscopic tests. Formulations for the synthesis of RPUFs were developed on the basis of the obtained research results. A mixture of polyols based on MSA and PLA in a weight ratio of 1:1 was used as the polyol component in the polyurethane formulation. The reference foam in these tests was a foam that was synthesized only on the basis of MSA-polyol. The obtained RPUFs were tested for basic functional properties (apparent density, compressive strength, water absorption, thermal conductivity coefficient etc.). Susceptibility to biodegradation in soil environment was also tested. It was found that the use of mixture of polyols based on MSA and PLA positively affected the properties of the obtained foam. The polyurethane foam based on this polyol mixture showed good thermal resistance and significantly reduced flammability in comparison with the foam based MSA-polyol. Moreover, it showed higher compressive strength, lower thermal conductivity and biodegradability in soil. The results of the conducted tests confirmed that the new foam was characterized by very good performance properties. In addition, this research provides information on new waste management opportunities and fits into the doctrine of sustainable resource management offered by the circular economy.


Assuntos
Plásticos Biodegradáveis/síntese química , Poliésteres/química , Polímeros/química , Poliuretanos/química , Força Compressiva , Silicatos/química
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