Thermodynamically controlled crystallization of glucose pentaacetates from amorphous phase

The α and β glucose pentaacetates are known sugar derivatives, which can be potentially used as stabilizers of amorphous phase of active ingredients of drugs (API). In the present work, crystallization behavior of equimolar mixture of α and β form in comparison to both pure anomers is revealed. It was shown that despite the same molecular interactions and similar molecular dynamics, crystallization from amorphous phase is significantly suppressed in equimolar mixture. Time dependent X-ray diffraction studies confirmed higher stability of the quenched amorphous equimolar mixture. Its tendency to crystallization is about 10 times lower than for pure anomers. Calorimetric studies revealed that the α and β anomers don't form solid solutions and have eutectic point for xα = 0.625. Suppressed crystallization tendency in the mixture is probably caused by the altered thermodynamics of the system. The factors such as difference of free energy between crystalline and amorphous state or altered configurational entropy are probably responsible for the inhibitory effect

Structure and properties of slow-resorbing nanofibers obtained by (co-axial) electrospinning as tissue scaffolds in regenerative medicine

With the rapid advancement of regenerative medicine technologies, there is an urgent need for the development of new, cell-friendly techniques for obtaining nanofibers—the raw material for an artificial extracellular matrix production. We investigated the structure and properties of PCL10 nanofibers, PCL5/PCL10 core-shell type nanofibers, as well as PCL5/PCLAg nanofibres prepared by electrospinning. For the production of the fiber variants, a 5–10% solution of polycaprolactone (PCL) (Mw = 70,000–90,000), dissolved in a mixture of formic acid and acetic acid at a ratio of 70:30 m/m was used. In order to obtain fibers containing PCLAg 1% of silver nanoparticles was added. The electrospin was conducted using the above-described solutions at the electrostatic field. The subsequent bio-analysis shows that synthesis of core-shell nanofibers PCL5/PCL10, and the silver-doped variant nanofiber core shell PCL5/PCLAg, by using organic acids as solvents, is a robust technique. Furthermore, the incorporation of silver nanoparticles into PCL5/PCLAg makes such nanofibers toxic to model microbes without compromising its biocompatibility. Nanofibers obtained such way may then be used in regenerative medicine, for the preparation of extracellular scaffolds: (i) for controlled bone regeneration due to the long decay time of the PCL, (ii) as bioscaffolds for generation of other types of artificial tissues, (iii) and as carriers of nanocapsules for local drug delivery. Furthermore, the used solvents are significantly less toxic than the solvents for polycaprolactone currently commonly used in electrospin, like for example chloroform (CHCl3), methanol (CH3OH), dimethylformamide (C3H7NO) or tetrahydrofuran (C4H8O), hence the presented here electrospin technique may allow for the production of multilayer nanofibres more suitable for the use in medical field

Comparison of Physicochemical, Mechanical, and (Micro-)Biological Properties of Sintered Scaffolds Based on Natural- and Synthetic Hydroxyapatite Supplemented with Selected Dopants

The specific combinations of materials and dopants presented in this work have not been previously described. The main goal of the presented work was to prepare and compare the different properties of newly developed composite materials manufactured by sintering. The synthetic-(SHAP) or natural- (NHAP) hydroxyapatite serves as a matrix and was doped with: (i) organic: multiwalled carbon nanotubes (MWCNT), fullerenes C60, (ii) inorganic: Cu nanowires. Research undertaken was aimed at seeking novel candidates for bone replacement biomaterials based on hydroxyapatite—the main inorganic component of bone, because bone reconstructive surgery is currently mostly carried out with the use of autografts; titanium or other non-hydroxyapatite -based materials. The physicomechanical properties of the developed biomaterials were tested by Scanning Electron Microscopy (SEM), Dielectric Spectroscopy (BSD), Nuclear Magnetic Resonance (NMR), and Differential Scanning Calorimetry (DSC), as well as microhardness using Vickers method. The results showed that despite obtaining porous sinters. The highest microhardness was achieved for composite materials based on NHAP. Based on NMR spectroscopy, residue organic substances could be observed in NHAP composites, probably due to the organic structures that make up the tooth. Microbiology investigations showed that the selected samples exhibit bacteriostatic properties against Gram-positive reference bacterial strain S. epidermidis (ATCC 12228); however, the property was much less pronounced against Gram-negative reference strain E. coli (ATCC 25922). Both NHAP and SHAP, as well as their doped derivates, displayed in good general compatibility, with the exception of Cu-nanowire doped derivates

Silk Powder from Cocoons and Woven Fabric as a Potential Bio-Modifier

Silk, as a protein fiber characterized by high biocompatibility, biodegradability, and low toxicity, is mainly used as textile structures for various purposes, including for biological applications. The key issue for unlimited silk applicability as a modifier is to prepare its relevant form to cover or introduce to other materials. This study presents silk powder fabrication from Bombyx mori cocoons and non-dyed silk woven fabric through cryogenic milling. The cocoons were milled before and after the degumming process to obtain powders from raw structures and pure fibroin. The powder morphology and composition were analyzed using scanning electron microscopy and energy dispersive spectroscopy. The influence of the milling on the silk structure was studied using infrared and Raman spectroscopies, indicating that silk powders retained dominant β-sheet structure. The powders were also analyzed by differential scanning calorimetry and thermogravimetric techniques. The thermal endothermic peak and onset temperature characteristic for silk decomposition shifted to the lower values for all powders, indicating less thermal stability. However, the process was found to be an efficient way to obtain silk powders. The new milled form of silk can allow its introduction into different matrices or form coatings without using any harsh solvents, enriching them with new features and make more biologically friendly

Effects of electro-conductive, biomaterial-based tissue scaffolds on stem cells and transdifferentiation-derived somatic cells

This is the final version of the article, which has been published in final form at / http://www.lestudium-ias.com/content/effects-electro-conductive-biomaterial-based-tissue-scaffolds-stem-cells-and-1The combination of stem cell therapy with a supportive scaffold is a promising approach to improving tissue engineering. We aim producing novel material composites that may serve as artificial Extracellular Matrix (ECM). The natural ECM is composed of an organic (protein, polysaccharide) and inorganic (i.e. hydroxy-apatite) components that when combined with the cells form a tissue. ECM is an integral part of every tissue that besides providing the environment for cells to grow, it also improves tissue’s mechanical properties. It provides elasticity, flexibility and durability for the tissue. Tissue engineering approaches utilize artificial materials (biomaterials) as a substitute of natural ECM. The process of producing tissue scaffolds obtained from biodegradable polymers has become a very intensively researched area for the past several years. Most of the current work focuses on the design and preparation of scaffolds with use of various production technologies and different natural materials like chitosan, collagen, elastin and different synthetic ones, like polymer polycaprolactone (PCL), poly(lactic acid) (PLA), poly(ethylene oxide) (PEO). The objective of this study was to check the impact of the biomaterials on various cell types, and compare their growth pattern. Biodegradable PCL, and five of its hybrids: PCL+SHAP (SHAP, synthetic hydroxyapatite), PCL+NHAP (NHAP, natural hydroxyapatite), PCL+PLGA (PLGA, poly(lactide-co-glycolide), PCL+CaCO3, PCL+SHAP+NHAP+CaCO3 as well as one non degradable biomaterial: polyacrylonitryl (PAN), were tested. For the experiments four different cell types were used: human dermal skin fibroblasts, B16F10 (mouse melanoma cells), HSkMEC (Human Skin Microvascular Endothelial Cells) and HEPC-CB1 (Human Endothelial Progenitor Cells –Cord Blood 1). Impacts of the biomaterials on cells were assessed: 1) by measuring cytotoxic effect of the biomaterials liquid extracts and 2) by direct contact test. The ability of cells to attach to the biomaterials was tested as well as cells’ potential to growth and proliferate on the surface of the biomaterials. None of the tested biomaterials was cytotoxic towards the tested cells, making them a potential valuable raw ingredient for 3D scaffold development that would find its applications in tissue engineering. The differences in efficiency of cells attachment and proliferation between tested biomaterials and cells lines were observed. In addition, a stimulating effect of the biomaterials on cells growth was also detected

Selected biodegradable and nonbiodegradable materials - their impact on cells growth and proliferation

International audienc

What would you like to print? Students' opinions on the use of 3D printing technology in medicine.

BackgroundRecent advances in 3D printing technology, and biomaterials are revolutionizing medicine. The beneficiaries of this technology are primarily patients, but also students of medical faculties. Taking into account that not all students have full, direct access to the latest advances in additive technologies, we surveyed their opinion on 3D printing and education in this area. The research aimed to determine what knowledge about the use of 3D printing technology in medicine, do students of medical faculties have.MethodsThe research was carried out in the form of a questionnaire among 430 students of the Medical University of Silesia in Katowice (Poland) representing various fields of medicine and health sciences. The questions included in the survey analyzed the knowledge of the respondents for 3D printing technology and the opportunities it creates in medicine.ResultsThe results indicate that students do have knowledge about 3D printing obtained mainly from the internet. They would be happy to deepen their knowledge at specialized courses in this field. Students appreciated the value of 3D printing in order to obtain accurate anatomical models, helpful in learning. However, they do not consider the possibility of complete abandonment of human cadavers in the anatomy classes. Their knowledge includes basic information about current applications of 3D printing in medicine, but not in all areas. However, they have no ethical doubts regarding the use of 3D printing in any form. The vast majority of students deemed it necessary to incorporate information regarding 3D printing technology into the curriculum of different medical majors.ConclusionThis research is the first of its kind, which allows for probing students' knowledge about the additive technologies in medicine. Medical education should be extended to include issues related to the use of 3D printing for medical applications

Magnetocaloric Properties of Mn1.1Fe0.9P0.5As0.5−xGex (0 ≤ x ≤ 0.1) Compounds

Intermetallic compounds with the overall formula Mn1.1Fe0.9P0.5As0.5-xGex (x varies from 0 to 0.1) were investigated in order to study their magnetocaloric effect by monitoring the adiabatic temperature change, magnetic entropy change and their relation to structural parameters. It was found that the maximum of magnetocaloric effect was achieved for x = 0.02. Adiabatic temperature change for consolidated powder was equal to 2.75 K for the magnetic field change ΔB = 1.7 T for the sample with x = 0.02. For the pure non-doped sample, this parameter is much lower: ΔTad = 1.7 K @ ΔB = 1.7 T. This result was correlated with the change of structural parameters such as lattice constants and the unit cell volume

Zastosowanie druku 3D w chirurgii głowy i szyi

Currently, 3D printing in medicine does not comprise only prostheses or implants, but also medical modelling and surgical planning. The future of 3D printing is printing combined with tissue bioengineering (bioprinting). Scaffolds made in 3D technology containing living cells are a step to creating tissues and organs. Three-dimensional printing in surgery is now considered the future of reconstructive and regenerative medicine. Head and neck surgery also benefits from advances in 3D printing. In this article, we will describe some of the possibilities offered by 3D printing in the aspect of education, training, and printed prostheses for the needs of head and neck surgery.Obecnie druk 3D w medycynie oznacza nie tylko protezy czy implanty, ale także modelowanie medyczne i planowanie chirurgiczne. Przyszłością będzie druk 3D połączony z bioinżynierią tkankową (bioprinting). Rusztowania wykonane w technologii 3D zawierające żywe komórki są krokiem do tworzenia tkanek i narządów. Druk trójwymiarowy w chirurgii uważany jest obecnie za przyszłość medycyny rekonstrukcyjnej i regeneracyjnej, a z dokonań na tym polu korzysta także chirurgia głowy i szyi. W prezentowanym artykule opiszemy niektóre możliwości, jakie daje druk 3D w aspekcie edukacji, szkoleń oraz drukowanych protez na potrzeby chirurgii głowy i szyi