Laser-Assisted Fabrication of Injectable Nanofibrous Cell Carriers.

The use of injectable biomaterials for cell delivery is a rapidly expanding field which may revolutionize the medical treatments by making them less invasive. However, creating desirable cell carriers poses significant challenges to the clinical implementation of cell-based therapeutics. At the same time, no method has been developed to produce injectable microscaffolds (MSs) from electrospun materials. Here the fabrication of injectable electrospun nanofibers is reported on, which retain their fibrous structure to mimic the extracellular matrix. The laser-assisted micro-scaffold fabrication has produced tens of thousands of MSs in a short time. An efficient attachment of cells to the surface and their proliferation is observed, creating cell-populated MSs. The cytocompatibility assays proved their biocompatibility, safety, and potential as cell carriers. Ex vivo results with the use of bone and cartilage tissues proved that NaOH hydrolyzed and chitosan functionalized MSs are compatible with living tissues and readily populated with cells. Injectability studies of MSs showed a high injectability rate, while at the same time, the force needed to eject the load is no higher than 25 N. In the future, the produced MSs may be studied more in-depth as cell carriers in minimally invasive cell therapies and 3D bioprinting applications.

Polymer-Based Nanomaterials for Photothermal Therapy: From Light-Responsive to Multifunctional Nanoplatforms for Synergistically Combined Technologies.

Materials for the treatment of cancer have been studied comprehensively over the past few decades. Among the various kinds of biomaterials, polymer-based nanomaterials represent one of the most interesting research directions in nanomedicine because their controlled synthesis and tailored designs make it possible to obtain nanostructures with biomimetic features and outstanding biocompatibility. Understanding the chemical and physical mechanisms behind the cascading stimuli-responsiveness of smart polymers is fundamental for the design of multifunctional nanomaterials to be used as photothermal agents for targeted polytherapy. In this review, we offer an in-depth overview of the recent advances in polymer nanomaterials for photothermal therapy, describing the features of three different types of polymer-based nanomaterials. In each case, we systematically show the relevant benefits, highlighting the strategies for developing light-controlled multifunctional nanoplatforms that are responsive in a cascade manner and addressing the open issues by means of an inclusive state-of-the-art review. Moreover, we face further challenges and provide new perspectives for future strategies for developing novel polymeric nanomaterials for photothermally assisted therapies.

Gender differences and typical nutrition concerns of the diets of preschool children - the results of the first stage of an intervention study.

BACKGROUND: Nutrition in children has an important influence on health both in childhood and adulthood. Actions aimed at improving children's nutrition are essential, not only to the children and their families, but also to the whole society. The aim of the study was to present the results of nutrient intake before starting a nutrition and physical activity intervention programme, to investigate gender differences in nutrient intake and to discuss whether the preschoolers' nutrient intake is similar to the intake of their peers from other countries. METHODS: Nutrient intake was estimated from seven-day weighed food records kept by parents and preschool staff individually for 122 4-6-year-old children who attended two preschools in Pila, north-western Poland. Nutrient intake was calculated using Dieta 4.0 computer programme including water intake and intake of nutrients from dietary supplements. Statistical analysis was performed using the IBM SPSS Statistics computer programme, version 21.0, according to gender. The study was approved by the Bioethics Committee of the Poznan University of Medical Sciences (reference number 886/08). RESULTS: Boys, in comparison to girls, were found to have statistically significantly higher intakes of total protein, total protein per kg of body weight, saturated fatty acids, total carbohydrates, available carbohydrates, lactose, sucrose, total water, vitamin A, beta-carotene, vitamin B2, vitamin B12, vitamin C, calcium, phosphorus, and magnesium. Statistically significantly higher percentage of girls than boys had intakes of vitamin E below AI. CONCLUSIONS: Gender was a significant factor of nutrient intake in the studied preschool children. The main nutritional concerns in the studied preschoolers' diets, irrespective of gender, are typical of the diets of preschool children from various parts of Europe and indicate the need to work out common nutritional strategies to improve preschoolers' nutrition across Europe to reduce future burden of diet-related diseases to the European societies.

Review of the studies on nutrition in Polish preschool children. Part 2. Meals prepared at preschool

This article is the second part of the review of the studies on nutrition in Polish preschool children. In the first part, studies on preschool menus assessment were presented and summarised, whereas this article reviews the studies on the assessment of foods and meals prepared at preschool. The aim of this review was to present and summarise the results of the studies on the assessment of meals prepared for children at preschool based on the reports from the preschool food storeroom, the studies on chemical analysis of sample meals served at preschools and the studies on comparison of the results of chemical analysis to the results obtained by calculations obtained from computer programmes. The results of the studies on the assessment of meals prepared for children at preschool using various methods confirm most of the findings from the studies on the assessment of preschool menus. It is necessary to carry out more studies on energy and nutrient content assessment of preschool meals determined by chemical analysis of sample meals in order to provide more accurate information about the real nutritional value of meals served to children at preschool. It is essential to update the Polish food composition tables to enable more precise calculations of nutritional value of the meals planned for children at preschools which will improve the possibility of adjusting preschool meals to the real needs of both 3-year-old and 4-6-year-old children during their stay at preschool.

Influence of conductive carbon and MnCo2O4 on morphological and electrical properties of hydrogels for electrochemical energy conversion.

In this work, a strategy for one-stage synthesis of polymer composites based on PNIPAAm hydrogel was presented. Both conductive particles in the form of conductive carbon black (cCB) and MnCo2O4 (MCO) spinel particles were suspended in the three-dimensional structure of the hydrogel. The MCO particles in the resulting hydrogel composite acted as an electrocatalyst in the oxygen evolution reaction. Morphological studies confirmed that the added particles were incorporated and, in the case of a higher concentration of cCB particles, also bound to the surface of the structure of the hydrogel matrix. The produced composite materials were tested in terms of their electrical properties, showing that an increase in the concentration of conductive particles in the hydrogel structure translates into a lowering of the impedance modulus and an increase in the double-layer capacitance of the electrode. This, in turn, resulted in a higher catalytic activity of the electrode in the oxygen evolution reaction. The use of a hydrogel as a matrix to suspend the catalyst particles, and thus increase their availability through the electrolyte, seems to be an interesting and promising application approach.

Brownian Motion in Optical Tweezers, a Comparison between MD Simulations and Experimental Data in the Ballistic Regime.

The four most popular water models in molecular dynamics were studied in large-scale simulations of Brownian motion of colloidal particles in optical tweezers and then compared with experimental measurements in the same time scale. We present the most direct comparison of colloidal polystyrene particle diffusion in molecular dynamics simulations and experimental data on the same time scales in the ballistic regime. The four most popular water models, all of which take into account electrostatic interactions, are tested and compared based on yielded results and resources required. Three different conditions were simulated: a freely moving particle and one in a potential force field with two different strengths based on 1 pN/nm and 10 pN/nm. In all cases, the diameter of the colloidal particle was 50 nm. The acquired data were compared with experimental measurements performed using optical tweezers with position capture rates as high as 125 MHz. The experiments were performed in pure water on polystyrene particles with a 1 µm diameter in special microchannel cells.

Gender and the length of time since autologous hematopoietic stem cell transplantation-What is their influence on the immune reconstitution in multiple myeloma patients?

INTRODUCTION: In the literature there is lack of information on the influence of gender and time since autologous hematopoietic stem cell transplantation (HSCT) on the immune reconstitution in multiple myeloma (MM) patients. OBJECTIVE: The aim of this study was to assess the diversity of the immune reconstitution according to gender in MM patients after autologous HSCT on the day of the clinic discharge and on the 29th day after discharge, as well as to investigate the changes in the immune system in females and males after staying at home for 28 days. METHOD: The studied population comprised 13 females and 13 males after autologous HSCT. On the day of the clinic discharge and on the 29th day after discharge blood samples were taken to analyse 22 immunological parameters. Statistical analysis was performed using STATISTICA 10 StatSoft Poland. For multiple comparisons, the Bonferroni correction was used. RESULTS: No statistically significant differences were observed in the analysed immunological parameters between the studied females and males with MM on the day of the clinic discharge and on the 29th day after discharge. However, on the 29th day after the clinic discharge compared to the day of the clinic discharge, statistically significant differences were found in 8 immunological parameters among females and 6 immunological parameters among males. CONCLUSION AND RECOMMENDATION: Our results indicate that the immune reconstitution is similar but not the same in patients of both genders. Statistically significant differences in the immune response in the studied females and males imply that gender may play a role in the immune reconstitution and that the results obtained in MM patients should be analysed separately in females and males. In order to explain the observed changes in the immune system according to gender, further research should be carried out on a larger population. This would most probably make it possible to find their clinical application.

Multifunctional Platform Based on Electrospun Nanofibers and Plasmonic Hydrogel: A Smart Nanostructured Pillow for Near-Infrared Light-Driven Biomedical Applications.

Multifunctional nanomaterials with the ability to respond to near-infrared (NIR) light stimulation are vital for the development of highly efficient biomedical nanoplatforms with a polytherapeutic approach. Inspired by the mesoglea structure of jellyfish bells, a biomimetic multifunctional nanostructured pillow with fast photothermal responsiveness for NIR light-controlled on-demand drug delivery is developed. We fabricate a nanoplatform with several hierarchical levels designed to generate a series of controlled, rapid, and reversible cascade-like structural changes upon NIR light irradiation. The mechanical contraction of the nanostructured platform, resulting from the increase of temperature to 42 °C due to plasmonic hydrogel-light interaction, causes a rapid expulsion of water from the inner structure, passing through an electrospun membrane anchored onto the hydrogel core. The mutual effects of the rise in temperature and water flow stimulate the release of molecules from the nanofibers. To expand the potential applications of the biomimetic platform, the photothermal responsiveness to reach the typical temperature level for performing photothermal therapy (PTT) is designed. The on-demand drug model penetration into pig tissue demonstrates the efficiency of the nanostructured platform in the rapid and controlled release of molecules, while the high biocompatibility confirms the pillow potential for biomedical applications based on the NIR light-driven multitherapy strategy.

Lateral migration of electrospun hydrogel nanofilaments in an oscillatory flow.

The recent progress in bioengineering has created great interest in the dynamics and manipulation of long, deformable macromolecules interacting with fluid flow. We report experimental data on the cross-flow migration, bending, and buckling of extremely deformable hydrogel nanofilaments conveyed by an oscillatory flow into a microchannel. The changes in migration velocity and filament orientation are related to the flow velocity and the filament's initial position, deformation, and length. The observed migration dynamics of hydrogel filaments qualitatively confirms the validity of the previously developed worm-like bead-chain hydrodynamic model. The experimental data collected may help to verify the role of hydrodynamic interactions in molecular simulations of long molecular chains dynamics.

Back-trajectory modelling and DNA-based species-specific detection methods allow tracking of fungal spore transport in air masses.

Recent advances in molecular detection of living organisms facilitate the introduction of novel methods to studies of the transport of fungal spores over large distances. Monitoring the migration of airborne fungi using microscope based spore identification is limited when different species produce very similar spores. In our study, DNA-based monitoring with the use of species-specific probes allowed us to track the aerial movements of two important fungal pathogens of oilseed rape (Brassica napus L.), i.e., Leptosphaeria maculans and Leptosphaeria biglobosa, which have identical spore shape and size. The fungi were identified using dual-labelled fluorescent probes that were targeted to a ß-tubulin gene fragment of either Leptosphaeria species. Spore identification by Real-Time PCR techniques capable of detecting minute amounts of DNA of selected fungal species was combined with back-trajectory analysis, allowing the tracking of past movements of air masses using the Hybrid Single Particle Lagrangian Integrated Trajectory model. Over a study period spanning the previous decade (2006-2015) we investigated two specific events relating to the long distance transport of Leptosphaeria spp. spores to Szczecin in North-West Poland. Based on the above mentioned methods and the results obtained with the additional spore sampler located in nearby Szczecin, and operating at the ground level in an oilseed rape field, we have demonstrated that on both occasions the L. biglobosa spores originated from the Jutland Peninsula. This is the first successful attempt to combine analysis of back-trajectories of air masses with DNA-based identification of economically important pathogens of oilseed rape in Europe. In our studies, the timing of L. biglobosa ascospore dispersal in the air was unlikely to result in the infection of winter oilseed rape grown as a crop plant. However, the fungus could infect other host plants, such as vegetable brassicas, cruciferous weeds, spring rapeseed and winter rapeseed growing as a volunteer plant.

Hydrogel Nanofilaments via Core-Shell Electrospinning.

Recent biomedical hydrogels applications require the development of nanostructures with controlled diameter and adjustable mechanical properties. Here we present a technique for the production of flexible nanofilaments to be used as drug carriers or in microfluidics, with deformability and elasticity resembling those of long DNA chains. The fabrication method is based on the core-shell electrospinning technique with core solution polymerisation post electrospinning. Produced from the nanofibers highly deformable hydrogel nanofilaments are characterised by their Brownian motion and bending dynamics. The evaluated mechanical properties are compared with AFM nanoindentation tests.