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Biogenic silica (SiO2) sourced from living organisms, especially plants such as rice and other cereals, has recently been successfully applied in different polymeric compositions. Another rich source of biogenic silica is common horsetail (Equisetum arvense L.), containing up to 25% SiO2 in the dry matter. In this study, biogenic silica was obtained from horsetail powder by acid leaching in sulfuric acid and calcination at 400 °C. The analysis, including measurements of specific surface area using the Brunauer–Emmett–Teller method, assessment of crystallinity by X-ray diffraction, as well as chemical content analysis by Fourier-transform infrared spectroscopy showed that high-purity, high-surface mesoporous silica was obtained. The biogenic silica and horsetail powders were also introduced to polylactide (PLA) to determine their influence on the polymer's crystallization, which was studied in both non-isothermal and isothermal conditions by differential scanning calorimetry. The crystallization parameters were calculated according to the Avrami method based on isothermal crystallization curves at 100, 110 and 120 °C. The crystalline structures were observed by optical microscopy in polarized light. It was found that both fillers improve the crystallization of PLA, especially in low-supercooling conditions, so they can be successfully utilized in industrial applications, when high crystallinity of polylactide is needed. [ABSTRACT FROM AUTHOR]

The comparison of some changes occurring in the physical properties of poly(butylene succinate) (PBS) due to its modification with Laponite (LAP) was the objective of this study. The PBS composites, containing from 1 to 7 wt% LAP, were prepared by co-rotating twin screw extrusion. The geometrical surface structure of the samples' fractures and the LAP content in the individual composites were examined. In addition, changes in the mechanical and thermal properties, melt flow rate and moisture sorption of the composites were studied. It was found that LAP increases the elastic modulus of PBS and also decreases its impact strength and, in particular, its strain. The strength of PBS changes to a lesser extent with an increase in the LAP content, i.e., it slightly decreases in tensile tests or slightly increases in bending tests. LAP also lowers the flow rate of PBS and significantly increases moisture sorption. Moreover, the composites produced were characterized by a uniform distribution of the dispersed phase in the polymer matrix and an acceptable adhesion at the interface between the two components. [ABSTRACT FROM AUTHOR]

Curcumin and piperine are plant compounds known for their health-promoting properties, but their use in the prevention or treatment of various diseases is limited by their poor solubility. To overcome this drawback, the curcumin–piperine amorphous polymer–phospholipid dispersions were prepared by hot melt extrusion technology. X-ray powder diffraction indicated the formation of amorphous systems. Differential scanning calorimetry confirmed amorphization and provided information on the good miscibility of the active compound–polymer–phospholipid dispersions. Owing to Fourier-transform infrared spectroscopy, the intermolecular interactions in systems were investigated. In the biopharmaceutical properties assessment, the improvement in solubility as well as the maintenance of the supersaturation state were confirmed. Moreover, PAMPA models simulating the gastrointestinal tract and blood-brain barrier showed enhanced permeability of active compounds presented in dispersions compared to the crystalline form of individual compounds. The presented paper suggests that polymer–phospholipid dispersions advantageously impact the bioaccessibility of poorly soluble active compounds. [ABSTRACT FROM AUTHOR]

Pomegranate peel extract is known for its potent antibacterial, antiviral, antioxidant, anti-inflammatory, wound healing, and probiotic properties, leading to its use in treating oral infections. In the first stage of this work, for the first time, using the Design of Experiment (DoE) approach, pomegranate peel extract (70% methanol, temperature 70 °C, and three cycles per 90 min) was optimized and obtained, which showed optimal antioxidant and anti-inflammatory properties. The optimized extract showed antibacterial activity against oral pathogenic bacteria. The second part of this study focused on optimizing an electrospinning process for a combination of polycaprolactone (PCL) and polyvinylpyrrolidone (PVP) nanofibers loaded with the optimized pomegranate peel extract. The characterization of the nanofibers was confirmed by using SEM pictures, XRPD diffractograms, and IR-ATR spectra. The composition of the nanofibers can control the release; in the case of PVP–based nanofibers, immediate release was achieved within 30 min, while in the case of PCL/PVP, controlled release was completed within 24 h. Analysis of the effect of different scaffold compositions of the obtained electrofibers showed that those based on PCL/PVP had better wound healing potential. The proposed strategy to produce electrospun nanofibers with pomegranate peel extract is the first and innovative approach to better use the synergy of biological action of active compounds present in extracts in a patient-friendly pharmaceutical form, beneficial for treating oral infections. [ABSTRACT FROM AUTHOR]

The co-administration of curcumin and hesperetin might be beneficial in terms of neuroprotective activity; therefore, in this study, we attempted to develop a fixed-dose formulation comprising these two compounds in an amorphous state. The aim of obtaining an amorphous state was to overcome the limitations of the low solubility of the active compounds. First, we assessed the possibility of using popular sweeteners (erythritol, xylitol, and sorbitol) as plasticizers to reduce the glass transition temperature of PVP K30 to prepare the polymer–excipient blends, which allowed the preparation of amorphous solid dispersions via hot-melt extrusion at a temperature below the original glass transition of PVP K30. Erythritol proved to be the superior plasticizer. Then, we focused on the development of fixed-dose amorphous solid dispersions of curcumin and hesperetin. Powder X-ray diffraction and thermal analysis confirmed the amorphous character of dispersions, whereas infrared spectroscopy helped to assess the presence of intermolecular interactions. The amorphous state of the produced dispersions was maintained for 6 months, as shown in a stability study. Pharmaceutical parameters such as dissolution rate, solubility, and in vitro permeability through artificial membranes were evaluated. The best improvement in these features was noted for the dispersion, which contained 15% of the total content of the active compounds with erythritol used as the plasticizer. [ABSTRACT FROM AUTHOR]

Marigold flower is a traditionally used plant material topically applied on the skin due to its anti-inflammatory properties and antibacterial activity. This potential of action justifies the implementation of marigold extract in nanofiber scaffolds based on poly-vinylpyrrolidone/hydroxypropyl-β-cyclodextrin (PVP/HPβCD) and polycaprolactone/polyvinylpyrrolidone (PCL/PVP) obtained by electrospinning for wound treatment. Using SEM, the morphology of electrospun scaffolds showed a fiber diameter in the range of 298–527 nm, with a uniform and bead-free appearance. ATR-FTIR spectroscopy confirmed the presence of marigold extracts in nanofibrous scaffolds. The composition of the nanofibers can control the release; in the case of PVP/HPβCD, immediate release of 80% of chlorogenic acid (an analytical and functional marker for marigold extract) was achieved within 30 min, while in the case of PCL/PVP, the controlled release was achieved within 24 h (70% of chlorogenic acid). All systems showed weak antibacterial activity against skin and wound-infecting bacteria Staphylococcus aureus (MIC 100 mg/mL), and Pseudomonas aeruginosa (MIC 200 mg/mL) and yeasts Candida albicans (MIC 100 mg/mL). Analysis of the effect of different scaffold compositions of the obtained electrofibers showed that those based on PCL/PVP had better wound healing potential. The scratch was closed after 36 h, compared to the 48 h required for PVP/HPβCD. Overall, the study shows that scaffolds of PCL/PVP nanofibers loaded with classic marigold extract have the best potential as wound dressing materials because of their ability to selectively modulate inflammation (via inhibition of hyaluronidase enzyme) and supportive antimicrobial properties, thereby aiding in the early stages of wound healing and repair. [ABSTRACT FROM AUTHOR]

Pomegranate flower extract, rich in anthocyanins, demonstrates beneficial health-promoting properties such as an anti-diabetic and antioxidant effect, among others. However, the potential health-promoting properties may be hindered by the low stability of anthocyanins. Therefore, the aim of our study was to assess whether stabilizing carriers, namely HP-γ-cyclodextrin (HP-γ-CD), α-cyclodextrin (α-CD), Methyl-β-cyclodextrin (Me-β-CD), Inulin (Inu) and Arabic gum (AGu) affect the antioxidant and antidiabetic activity of lyophilized pomegranate flower extract, how they influence stability, release profile, and whether the systems exhibit prebiotic activity. Interactions between pomegranate flower extract and these factors were analyzed using FT-IR. The structures were examined through microscopic imaging while for the prepared prebiotic systems, antidiabetic activity was determined and confirmed by the inhibition of α-amylase and α-glucosidase; antioxidant activity was expressed by DPPH and CUPRAC assays. The content of pelargonidin-3,5-glucoside in these systems was assessed using the HPLC method. The release profiles of pelargonidin-3,5-glucoside were examined in a medium at pH = 6.8 and pH = 1.2, and the stability was assessed after subjecting the systems to high temperatures (T = 90 °C). The prebiotic potential was evaluated for 10 prebiotic bacterial strains (Lactobacillus acidophilus, Lactobacillus casei, Lactobacillus plantarum, Lactobacillus brevis Lactobacillus rhamnosus gg, Lactobacillus reuteri, Pediococcus pentosaceus, Lactococcus lactis, Lactobacillus fermentum lf, Streptococcus thermophilus). As a result of the conducted research, better functionalities of the obtained systems containing Pomegranate flower extract were proven in terms of prebiotic and antidiabetic effects. The obtained delivery systems for pelargonidin-3,5-glucoside allow for better use of its health-promoting effects. [ABSTRACT FROM AUTHOR]

The plant material Scutellariae baicalensis radix, which is rich in flavones (baicalin), possesses antibacterial, antifungal, antioxidant, and anti-inflammatory properties. This work aimed to develop a 3D-printed chitosan-based hydrogel rich in Scutellariae baicalensis extract as an innovative approach for the personalized treatment of periodontal diseases. Chitosan-based hydrogels were prepared, and the printability of the prepared hydrogels was determined. The hydrogel with 2.5% w/v of high molecular-weight chitosan (CS), 2% w/v gelatin (Gel), and 10% w/w of extract (Ex) presented the best printability, producing smooth and uniform scaffolds. It was proved that the CS/Gel/Ex hydrogel was stabilized by hydrogen bonds and remained in amorphous dispersion in the 3D-printed structures (confirmed by ATR-FTIR and XRPD). Due to the amorphization of the active substance, a significant increase in the release of baicalin in vitro was observed. It was demonstrated that there was an initial burst release and a continuous release profile (n = 3). Higuchi kinetic was the most likely baicalin release kinetic. The second fit, the Korsmeyer–Peppas kinetics model, showed coupled diffusion of the active ingredient in the hydrated matrix and polymer relaxation regulated release, with n values ranging from 0.45 to 0.89. The anti-inflammatory properties of 3D-printed scaffolds were assessed as the ability to inhibit the activity of the hyaluronidase enzyme. Activity was assessed as IC50 = 63.57 ± 4.98 mg hydrogel/mL (n = 6). Cytotoxicity tests demonstrated the biocompatibility of the material. After 24 h of exposure to the 2.5CS/2Gel/10Ex scaffold, fibroblasts migrated toward the scratch, closed the "wound" by 97.1%, and significantly accelerated the wound healing process. The results render the 3D-printed CS/Gel/extract scaffolds as potential candidates for treating periodontal diseases. [ABSTRACT FROM AUTHOR]

The main aims of thin biofilm synthesis are to either achieve a new form to promote the transport of drugs in oral delivery systems or as a coating to improve the biocompatibility of the implant's surface. In this study, the Langmuir monolayer technique was employed to obtain films containing Mg-doped hydroxyapatite with 0.5%, 1.0%, and 1.5% Mg(II). The obtained modified HA particles were analysed via the FT-IR, XRD, DLS, and SEM methods. It was shown that the modified hydroxyapatite particles were able to form thin films at the air/water interface. BAM microscopy was employed to characterized the morphology of these films. In the next step, the mixed films were prepared using phospholipid (DPPC) molecules and modified hydroxyapatite particles (HA-Mg(II)). We expected that the presence of phospholipids (DPPC) in thin films improved the biocompatibility of the preparing films, while adding HA-Mg(II) particles will promote antibacterial properties and enhance osteogenesis processes. The films were prepared in two ways: (1) by mixing DPPC and HA-Mg (II) and spreading this solution onto the subphase, or (2) by forming DPPC films, dropping the HA-Mg (II) dispersion onto the phospholipid monolayer. Based on the obtained π–A isotherms, the surface parameters of the achieved thin films were estimated. It was observed that the HA-Mg(II) films can be stabilized with phospholipid molecules, and a more stable structure was obtained from films synthesied via method (2). [ABSTRACT FROM AUTHOR]

Despite the wide pharmacological action of polyphenols, their usefulness is limited due to their low oral bioavailability, which is due to their low solubility and rapid first-pass metabolism. Red vine leaf extract is an herbal medicine containing several polyphenols, with resveratrol and polydatin as the main compounds exhibiting antioxidant and anti-inflammatory properties. In the first stage of the work, using the Design of Experiment (DoE) approach, the red vine leaf extract (50% methanol, temperature 70 °C, and three cycles per 60 min) was obtained, which showed optimal antioxidant and anti-inflammatory properties. In order to circumvent the above-described limitations and use innovative technology, electrospun nanofibers containing the red vine leaf extract, polyvinylpyrrolidone (PVP), and hydroxypropyl-β-cyclodextrin (HPβCD) were first developed. The optimization of the process involved the time of system mixing prior to electrospinning, the mixture flow rate, and the rotation speed of the collector. Dissolution studies of nanofibers showed improved resveratrol release from the nanofibers (over five-fold). Additionally, a PAMPA-GIT assay confirmed significantly better buccal penetration of resveratrol from this nanofiber combination (over ten-fold). The proposed strategy for electrospun nanofibers with the red vine leaf extract is an innovative approach to better use the synergy of the biological action of active compounds present in extracts that are beneficial for the development of nutraceuticals. [ABSTRACT FROM AUTHOR]

Three different types of solid dispersions based on polyvinyl polymers and related copolymers (Kollidon® VA64, Soluplus® and Kollicoat IR®) comprising polydatin-rich Polygoni cuspidati extract were prepared by hot melt extrusion. The systems were characterized using X-ray powder diffraction, infrared spectroscopy as well as by polydatin release and in vitro permeability. Mucoadhesive tablets were prepared from the extrudates based on Kollidon® VA64 and Soluplus® to obtain a suitable pharmaceutical form, where (hydroxypropyl)methyl cellulose was added as a mucoadhesive agent. The tablets were evaluated in terms of the kinetics of polydatin release as well as their mucoadhesive properties. The best tabletability properties, polydatin release profile and adequate mucoadhesive properties were obtained by the formulation containing the Kollidon® VA64-based extrudate, which makes it an excellent prototype for enhancing the release of poorly water-soluble compounds. [ABSTRACT FROM AUTHOR]

Hesperidin is a polyphenol derived from citrus fruits that has a broad potential for biological activity and the ability to positively modify the intestinal microbiome. However, its activity is limited by its low solubility and, thus, its bioavailability—this research aimed to develop a zein-based hesperidin system with increased solubility and a sustained release profile. The study used triple systems enriched with solubilizers to maximize solubility. The best system was the triple system hesperidin-zein-Hpβ-CD, for which the solubility improved by more than six times. A significant improvement in the antioxidant activity and the ability to inhibit α-glucosidase was also demonstrated, due to an improved solubility. A release profile analysis was performed in the subsequent part of the experiments, confirming the sustained release profile of hesperidin, while improving the solubility. Moreover, the ability of selected probiotic bacteria to metabolize hesperidin and the effect of this flavonoid compound on their growth were investigated. [ABSTRACT FROM AUTHOR]

The proven anti-neurodegenerative properties of caffeic acid in vivo are limited due to its poor solubility, which limits bioavailability. Therefore, caffeic acid delivery systems have been developed to improve caffeic acid solubility. Solid dispersions of caffeic acid and magnesium aluminometasilicate (Neusilin US2—Neu) were prepared using the ball milling and freeze-drying techniques. The solid dispersions of caffeic acid:Neu obtained by ball milling in a 1:1 mass ratio turned out to be the most effective. The identity of the studied system in comparison to the physical mixture was confirmed using the X-Ray Powder Diffractionand Fourier-transform infrared spectroscopy techniques. For caffeic acid with improved solubility, screening tests were carried out to assess its anti-neurodegenerative effect. The obtained results on the inhibition of acetylcholinesterase, butyrylcholinesterase, tyrosinase, and antioxidant potential provide evidence for improvement of caffeic acid's anti-neurodegenerative activity. As a result of in silico studies, we estimated which caffeic acid domains were involved in interactions with enzymes showing expression relevant to the neuroprotective activity. Importantly, the confirmed improvement in permeability of the soluble version of caffeic acid through membranes simulating the walls of the gastrointestinal tract and blood-brain barrier further strengthen the credibility of the results of in vivo anti-neurodegenerative screening tests. [ABSTRACT FROM AUTHOR]

Orange peel, which is a rich source of polyphenolic compounds, including hesperidin, is produced as waste in production. Therefore, optimization of the extraction of hesperidin was performed to obtain its highest content. The influence of process parameters such as the kind of extraction mixture, its temperature and the number of repetitions of the cycles on hesperidin content, the total content of phenolic compounds and antioxidant (DPPH scavenging assay) as well as anti-inflammation activities (inhibition of hyaluronidase activity) was checked. Methanol and temperature were key parameters determining the efficiency of extraction in terms of the possibility of extracting compounds with the highest biological activity. The optimal parameters of the orange peel extraction process were 70% of methanol in the extraction mixture, a temperature of 70 °C and 4 cycles per 20 min. The second part of the work focuses on developing electrospinning technology to synthesize nanofibers of polyvinylpyrrolidone (PVP) and hydroxypropyl-β-cyclodextrin (HPβCD) loaded with hesperidin-rich orange peel extract. This is a response to the circumvention of restrictions in the use of hesperidin due to its poor bioavailability resulting from low solubility and permeability. Dissolution studies showed improved hesperidin solubility (over eight-fold), while the PAMPA-GIT assay confirmed significantly better transmucosal penetration (over nine-fold). A DPPH scavenging assay of antioxidant activity as well as inhibition of hyaluronidase to express anti-inflammation activity was established for hesperidin in prepared electrospun nanofibers, especially those based on HPβCD and PVP. Thus, hesperidin-rich orange peel nanofibers may have potential buccal applications to induce improved systemic effects with pro-health biological activity. [ABSTRACT FROM AUTHOR]

Hot Melt Extrusion (HME) technology was developed to obtain blends containing lyophilized Scutellariae baicalensis root extract and chitosan in order to improve the rheological properties of the obtained blends, including tableting and compressibility properties. (Hydroxypropyl)methyl cellulose (HPMC) in 3 different ratios was used as amorphous matrix formers. The systems were characterized using X-ray powder diffraction (PXRD), Fourier Transform Infrared Spectroscopy with Attenuated Total Reflectance (FTIR-ATR), and in vitro release, permeability, and microbiological activity studies. Then, the extrudates were used to prepare tablets in order to give them the appropriate pharmaceutical form. HPMC-based systems released baicalin more slowly, resulting in delayed peaks in the acceptor fluid. This behavior can be explained by the fact that HPMC swells significantly, and the dissolved substance must have diffused through the polymer network before being released. The best tabletability properties are provided by the formulation containing the extrudate with lyophilized extract HPMC 50:50 w/w. These tablets offer a valuable baicalin release profile while maintaining good mucoadhesive properties that condition the tablet's retention in the application site and the effectiveness of therapy. [ABSTRACT FROM AUTHOR]

The low bioaccessibility of hesperetin and piperine hampers their application as therapeutic agents. Piperine has the ability to improve the bioavailability of many compounds when co-administered. The aim of this paper was to prepare and characterize the amorphous dispersions of hesperetin and piperine, which could help to improve solubility and boost the bioavailability of both plant-origin active compounds. The amorphous systems were successfully obtained by means of ball milling, as confirmed by XRPD and DSC studies. What's more, the FT-IR-ATR study was used to investigate the presence of intermolecular interactions between the systems' components. Amorphization enhanced the dissolution rate as a supersaturation state was reached, as well as improving the apparent solubility of both compounds by 245-fold and 183-fold, respectively, for hesperetin and piperine. In the in vitro permeability studies simulating gastrointestinal tract and blood-brain barrier permeabilities, these increased by 775-fold and 257-fold for hesperetin, whereas they were 68-fold and 66-fold for piperine in the GIT and BBB PAMPA models, respectively. Enhanced solubility had an advantageous impact on antioxidant as well as anti-butyrylcholinesterase activities—the best system inhibited 90.62 ± 0.58% of DPPH radicals and 87.57 ± 1.02% butyrylcholinesterase activity. To sum up, amorphization considerably improved the dissolution rate, apparent solubility, permeability, and biological activities of hesperetin and piperine. [ABSTRACT FROM AUTHOR]

In this work, NiAl-xWC (x = 0 − 90 wt.% WC) intermetallic-based composites were successfully synthesized by mechanical alloying (MA) and a hot-pressing approach. As initial powders, a mixture of nickel, aluminum and tungsten carbide was used. The phase changes in analyzed systems after mechanical alloying and hot pressing were evaluated by an X-ray diffraction method. Scanning electron microscopy and hardness test examination were used for evaluating microstructure and properties for all fabricated systems from the initial powder to the final sinter stage. The basic sinter properties were evaluated to estimate their relative densities. Synthesized and fabricated NiAl-xWC composites showed an interesting relationship between the structure of the constituting phases, analyzed by planimetric and structural methods and sintering temperature. The analyzed relationship proves that the structural order reconstructed by sintering strongly depends on the initial formulation and its decomposition after MA processing. The results confirm that it is possible to obtain an intermetallic NiAl phase after 10 h of MA. For processed powder mixtures, the results showed that increased WC content intensifies fragmentation and structural disintegration. The final structure of the sinters fabricated in lower (800 °C) and higher temperature regimes (1100 °C), consisted of recrystallized NiAl and WC phases. The macro hardness of sinters obtained at 1100 °C increased from 409 HV (NiAl) to 1800 HV (NiAl + 90% WC). Obtained results reveal a new applicable perspective in the field of intermetallic-based composites and remain highly anticipated for possible application in severe-wear or high-temperature conditions. [ABSTRACT FROM AUTHOR]

Rosmarinic acid (RA) is a natural antioxidant with neuroprotective properties; however, its preventive and therapeutic use is limited due to its slight solubility and poor permeability. This study aimed to improve RA physicochemical properties by systems formation with cyclodextrins (CDs): hydroxypropyl-α-CD (HP-α-CD), HP-β-CD, and HP-γ-CD, which were prepared by the solvent evaporation (s.e.) method. The interactions between components were determined by X-ray powder diffraction (XRPD), differential scanning calorimetry (DSC) and Fourier Transform infrared spectroscopy (FTIR). The sites of interaction between RA and CDs were suggested as a result of in silico studies focused on assessing the interaction between molecules. The impact of amorphous systems formation on water solubility, dissolution rate, gastrointestinal (GIT) permeability, and biological activity was studied. RA solubility was increased from 5.869 mg/mL to 113.027 mg/mL, 179.840 mg/mL, and 194.354 mg/mL by systems formation with HP-α-CD, HP-β-CD, and HP-γ-CD, respectively. During apparent solubility studies, the systems provided an acceleration of RA dissolution. Poor RA GIT permeability at pH 4.5 and 5.8, determined by parallel artificial membrane permeability assay (PAMPA system), was increased; RA–HP-γ-CD s.e. indicated the greatest improvement (at pH 4.5 from Papp 6.901 × 10−7 cm/s to 1.085 × 10−6 cm/s and at pH 5.8 from 5.019 × 10−7 cm/s to 9.680 × 10−7 cm/s). Antioxidant activity, which was determined by DPPH, ABTS, CUPRAC, and FRAP methods, was ameliorated by systems; the greatest results were obtained for RA–HP-γ-CD s.e. The inhibition of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) was increased from 36.876% for AChE and 13.68% for BChE to a maximum inhibition of the enzyme (plateau), and enabled reaching IC50 values for both enzymes by all systems. CDs are efficient excipients for improving RA physicochemical and biological properties. HP-γ-CD was the greatest one with potential for future food or dietary supplement applications. [ABSTRACT FROM AUTHOR]

The low bioavailability of resveratrol and polydatin obtained from Polygoni cuspidati extract limits the application of their pro-health properties. While nanofibers have attracted increasing attention in nutrition delivery due to their special properties, including an increase in the dissolution and permeability, which affects the bioavailability. Therefore, it is justified to obtain nanofibers from Polygoni cuspidati extract, which showed antioxidant and anti-inflammatory properties as a result of a presence of stilbene analogs in the Polygoni cuspidati extract (especially resveratrol and polydatin). In the first stage of the work, using the Design of Experiment (DoE) approach, the Polygoni cuspidati extract (70% of methanol, temperature 70 °C and 4 cycles) was obtained, which showed the best antioxidant and anti-inflammatory properties. Using the Polygoni cuspidati extract as a substrate, nanofibers were obtained by electrospinning. The identification of nanofibers was confirmed on the basis of the analysis of changes in XRPD diffractograms, SEM picture and FTIR-ATR spectra. Obtaining nanofibers from the Polygoni cuspidati extract significantly improved the solubility of resveratrol and polydatin (approx. 6-fold comparing to pure substance). As a consequence, the penetration coefficients of both tested resveratrol and polydatin also increased. The proposed strategy for the preparation of nanofibers from the Polygoni cuspidati extract is an innovative approach to better use the synergy of biological action of active compounds present in extracts. It is especially during the development of nutraceuticals based on the use of selected stilbenes. [ABSTRACT FROM AUTHOR]

Preparing structures with the sol-gel method often requires control of the basal plane of crystallites, crystallite structures, or the appearance of the voids. One of the critical factors in the formation of a layer are additives, such as aminoalcohols, which increase the control of the sol formation reaction. Since aminoalcohols differ in boiling points and alkalinity, their selection may play a significant role in the dynamics of structure formation. The main aim of this work is to examine the properties of ZnO layers grown using different aminoalcohols at different concentration rates. The layers were grown on various substrates, which would provide additional information on the behavior of the layers on a specific substrate, and the mixture was annealed at a relatively low temperature (400 °C). The research was conducted using monoethanolamine (MEA) and diethanolamine (DEA). The aminoalcohols were added to the solutions in equal concentrations. The microscopic image of the structure and the size of the crystallites were determined using micrographs. X-ray diffractometry and Raman spectroscopy were used for structural studies, phase analysis and to establish the purity of the obtained films. UV-vis absorption and photoluminescence were used to evaluate structural defects. This paper shows the influence of the stabilizer on the morphology of samples and the influence of the morphology and structure on the optical properties. The above comparison may allow the preparation of ZnO samples for specific applications. [ABSTRACT FROM AUTHOR]

This study aimed to investigate changes in the solubility and antimicrobial efficacy of cefuroxime axetil (CA) when incorporated into cyclodextrin (CD). While choosing the CD, the validated in silico model was used. A theoretical model based on docking and molecular mechanics/generalized born surface area was validated using a curated dataset of API (active pharmaceutical ingredient)-CD stability constants. The library of commonly used cyclodextrins was virtually screened, indicating CA -hydroxypropyl-βCD (HPβCD) as the most thermodynamically favored system. Solid-state CA-HPβCD system was prepared and characterized by differential scanning calorimetry (DSC), Fourier-transform infrared (FT-IR), and X-ray diffraction (XRPD) methods. The dissolution profiles of the CA and its cyclodextrin system were evaluated. Microbiological activity of the CA-HPβCD inclusion system was studied based on changes in minimal inhibitory concentration (MIC) values and related to ones of the pure CA. The theoretical model was successfully validated, obtaining an average correlation with experimental data R = 0.7. The dissolution study showed significantly improved dissolution profiles of CA-HPβCD compared to CA. HPβCD increases the antimicrobial efficacy of CA up to 4-fold compared to pure CA. [ABSTRACT FROM AUTHOR]

Titanium β-type alloys attract attention as biomaterials for dental applications. The aim of this work was the synthesis of nanostructured β type Ti23Mo-x wt % 45S5 Bioglass (x = 0, 3 and 10) composites by mechanical alloying and powder metallurgy methods and their characterization. The crystallization of the amorphous material upon annealing led to the formation of a nanostructured β type Ti23Mo alloy with a grain size of approximately 40 nm. With the increase of the 45S5 Bioglass contents in Ti23Mo, nanocomposite increase of the β-phase is noticeable. The electrochemical treatment in phosphoric acid electrolyte resulted in a porous surface, followed by bioactive ceramic Ca-P deposition. Corrosion resistance potentiodynamic testing in Ringer solution at 37 °C showed a positive effect of porosity and Ca-P deposition on nanostructured Ti23Mo 3 wt % 45S5 Bioglass nanocomposite. The contact angles of glycerol on the nanostructured Ti23Mo alloy were determined and show visible decrease for bulk Ti23Mo 3 wt % 45S5 Bioglass and etched Ti23Mo 3 wt % 45S5 Bioglass nanocomposites. In vitro tests culture of normal human osteoblast cells showed very good cell proliferation, colonization, and multilayering. The present study demonstrated that porous Ti23Mo 3 wt % 45S5 Bioglass nanocomposite is a promising biomaterial for bone tissue engineering. [ABSTRACT FROM AUTHOR]

Background: Naringenin (NAR) is a flavonoid with excellent antioxidant and neuroprotective potential that is limited by its low solubility. Thus, solid dispersions with β-cyclodextrin (β-CD), hydroxypropyl-β-cyclodextrin (HP-β-CD), hydroxypropylmethylcellulose (HPMC), and microenvironmental pH modifiers were prepared. Methods: The systems formation analysis was performed by X-Ray Powder Diffraction (XRPD) and Fourier-transform infrared spectroscopy (FT-IR). Water solubility and dissolution rates were studied with a pH of 1.2 and 6.8. In vitro permeability through the gastrointestinal tract (GIT) and the blood-brain barrier (BBB) was assessed with the parallel artificial membrane permeability assay (PAMPA) assay. The antioxidant activity was studied with the 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) and cupric ion reducing antioxidant capacity (CUPRAC) assays, while in vitro enzymes studies involved the inhibition of acetylcholinesterase, butyrylcholinesterase, and tyrosinase. For the most promising system, in silico studies were conducted. Results: NAR solubility was increased 458-fold by the solid dispersion NAR:HP-β-CD:NaHCO3 in a mass ratio of 1:3:1. The dissolution rate was elevated from 8.216% to 88.712% in a pH of 1.2 and from 11.644% to 88.843% in a pH of 6.8 (within 3 h). NAR GIT permeability, described as the apparent permeability coefficient, was increased from 2.789 × 10−6 cm s−1 to 2.909 × 10−5 cm s−1 in an acidic pH and from 1.197 × 10−6 cm s−1 to 2.145 × 10−5 cm s−1 in a basic pH. NAR BBB permeability was established as 4.275 × 10−6 cm s−1. The antioxidant activity and enzyme inhibition were also increased. Computational studies confirmed NAR:HP-β-CD inclusion complex formation. Conclusions: A significant improvement in NAR solubility was associated with an increase in its biological activity. [ABSTRACT FROM AUTHOR]

The paper presents the results of studies of microstructure, mechanical and physicochemical properties of surface layers produced by laser modification of the diffusion boron layer on Monel® Alloy 400. The diffusion boron layers were produced at 950 °C for 6 h. The gas-contact method was used in an open retort furnace. The process was carried out in a powder mixture containing B4C carbide as a boron source. The next stage was the modification of the boron layer with a diode laser beam of a nominal power of 3 kW. A constant power of 1400 W of the laser beam was used. The scanning speed was variable (successively 5 m/min, 25 m/min, 50 m/min). In order to determine the best parameters, single tracks were created, after which multiple tracks were prepared using previously selected parameters. It was found that both the diffusion borided layer and the laser modified layer had better properties than the substrate material. Both these processes contributed to an increase in corrosion resistance, hardness and wear resistance. It was also found that laser modification caused a slight deterioration of the properties in comparison with the diffusion borided layer. However, the laser modification process resulted in the production of a much thicker layer. [ABSTRACT FROM AUTHOR]

The amorphous form of carvedilol phosphate (CVD) was obtained as a result of grinding. The identity of the obtained amorphous form was confirmed by powder X-ray diffraction (PXRD), different scanning calorimetry (DSC), and FT-IR spectroscopy. The process was optimized in order to obtain the appropriate efficiency and time. The crystalline form of CVD was used as the reference standard. Solid dispersions of crystalline and amorphous CVD forms with hydrophilic polymers (hydroxypropyl-β-cyclodextrin, Pluronic® F-127, and Soluplus®) were obtained. Their solubility at pH 1.2 and 6.8 was carried out, as well as their permeation through a model system of biological membranes suitable for the gastrointestinal tract (PAMPA-GIT) was established. The influence of selected polymers on CVD properties was defined for the amorphous form regarding the crystalline form of CVD. As a result of grinding (four milling cycles lasting 15 min with 5 min breaks), amorphous CVD was obtained. Its presence was confirmed by the "halo effect" on the diffraction patterns, the disappearance of the peak at 160.5 °C in the thermograms, and the changes in position/disappearance of many characteristic bands on the FT-IR spectra. As a result of changes in the CVD structure, its lower solubility at pH 1.2 and pH 6.8 was noted. While the amorphous dispersions of CVD, especially with Pluronic® F-127, achieved better solubility than combinations of crystalline forms with excipients. Using the PAMPA-GIT model, amorphous CVD was assessed as high permeable (Papp > 1 × 10−6 cm/s), similarly with its amorphous dispersions with excipients (hydroxypropyl-β-cyclodextrin, Pluronic® F-127, and Soluplus®), although in their cases, the values of apparent constants permeability were decreased. [ABSTRACT FROM AUTHOR]

Chitosan is a valued excipient due to its biocompatibility properties and increasing solubility of poorly water-soluble drugs. The research presented in this paper concerns the preparation of binary combinations of chitosan (deacetylated chitin) with carvedilol (beta-blocker) to develop a formulation with a modified carvedilol release profile. As part of the research, six physical mixtures of chitosan with carvedilol were obtained and identified by spectral (PXRD, FT-IR, and Raman), thermal (DSC), and microscopic (SEM) methods. The next stage of the research estimated the profile changes and the dissolution rate for carvedilol in the obtained drug delivery systems; the reference sample was pure carvedilol. The studies were conducted at pH = 1.2 and 6.8, simulating the gastrointestinal tract conditions. Quantitative changes of carvedilol were determined using the developed isocratic UHPLC-DAD method. Established apparent permeability coefficients proved the changes in carvedilol's permeability after introducing a drug delivery system through membranes simulating the gastrointestinal tract and skin walls. A bioadhesive potential of carvedilol–chitosan systems was confirmed using the in vitro model. The conducted research and the obtained results indicate a significant potential of using chitosan as an excipient in modern oral or epidermal drug delivery systems of carvedilol. [ABSTRACT FROM AUTHOR]

To improve physicochemical properties of vardenafil hydrochloride (VAR), its amorphous form and combinations with excipients—hydroxypropyl methylcellulose (HPMC) and β-cyclodextrin (β-CD)—were prepared. The impact of the modification on physicochemical properties was estimated by comparing amorphous mixtures of VAR to their crystalline form. The amorphous form of VAR was obtained as a result of the freeze-drying process. Confirmation of the identity of the amorphous dispersion of VAR was obtained through the use of comprehensive analysis techniques—X-ray powder diffraction (PXRD) and differential scanning calorimetry (DSC), supported by FT-IR (Fourier-transform infrared spectroscopy) coupled with density functional theory (DFT) calculations. The amorphous mixtures of VAR increased its apparent solubility compared to the crystalline form. Moreover, a nearly 1.3-fold increase of amorphous VAR permeability through membranes simulating gastrointestinal epithelium as a consequence of the changes of apparent solubility (Papp crystalline VAR = 6.83 × 10−6 cm/s vs. Papp amorphous VAR = 8.75 × 10−6 cm/s) was observed, especially for its combinations with β-CD in the ratio of 1:5—more than 1.5-fold increase (Papp amorphous VAR = 8.75 × 10−6 cm/s vs. Papp amorphous VAR:β-CD 1:5 = 13.43 × 10−6 cm/s). The stability of the amorphous VAR was confirmed for 7 months. The HPMC and β-CD are effective modifiers of its apparent solubility and permeation through membranes simulating gastrointestinal epithelium, suggesting a possibility of a stronger pharmacological effect. [ABSTRACT FROM AUTHOR]

The paper presents study results focused on the microstructural, mechanical, and physicochemical properties of B-Cr coatings obtained by means of modification of diffusion borochromized layers by diode laser beam. The studies were conducted on 145Cr6 tool steel. Diffusion borochromized layers were produced at 950 °C in powder mixture containing boron carbides as a source of boron and ferrochrome as a source of chromium. In the next step these layers were remelted using laser beam. Powers: 600, 900, and 1200 W were used during these processes. The microstructure, microhardness, chemical composition, as well as wear and corrosion resistance of newly-formed B-Cr coatings were determined. As a result of laser beam interaction, the diffusion borochromized layer was mixed with the steel substrate. The study showed that too low laser beam power causes cracks in the newly formed B-Cr coating, and on the other hand, too higher laser beam power causes deep remelting resulting in the loss of microhardness. The reduced corrosion resistance in comparison with diffusion borochromized layers was caused by occurrence cracks or deep remelting. For B-Cr coatings produced using laser beam power 600 W, a small decrease in wear resistance was observed, but note that this coating was much thicker than diffusion borochromized layers. On the other hand, laser beam power of 1200 W caused a significant decrease in wear resistance. Newly formed B-Cr coatings had an advantageous microhardness gradient between the layer and the substrate. [ABSTRACT FROM AUTHOR]

Zinc oxide (ZnO) is one of the wide-bandgap semiconductors, which may be useful in a plethora of electronic, optical, piezoelectric, and scintillating applications. The following article consists in a structural and luminescence analysis of ZnO microfilms grown on a sapphire substrate with a sol–gel method. The films were annealed at different temperatures. The structures were investigated with the XRD and Raman methods, by which the influence of the substrate on the structure of the film was determined. The luminescence of films was investigated with room-temperature fluorescence, radioluminescence, and thermoluminescence. [ABSTRACT FROM AUTHOR]

The presence of active pharmaceutical ingredients (APIs) in the forms of different polymorphic states can induce differences in their physicochemical properties. In the case of poorly soluble APIs, like the oncological drug sorafenib tosylate, small variations in solubility may result in large bioavailability differences. The control of its therapeutic dose is crucial from the effective pharmacotherapy point of view and the reduction of side effects. Therefore, this study aimed to assess the influence of sorafenib tosylate polymorphic forms on its solubility and, consequently, permeability, based on passive diffusion through membranes simulating the gastrointestinal tract (GIT) conditions. In the first part of the work, two crystalline forms of sorafenib tosylate were identified using the X-ray powder diffraction, FT-IR, and Raman spectroscopy. Subsequently, solubility studies were carried out. Both forms of sorafenib tosylate were insoluble in 0.1 N hydrochloric acid (HCl), in acetate buffer (pH 4.5), and in phosphate buffer (pH 6.8). Solubility (mg/mL) of form I and III of sorafenib tosylate in 0.1 N HCl + 1.0% SDS was 0.314 ± 0.006 and 1.103 ± 0.014, respectively, in acetate buffer pH 4.5 + 1.0% SDS it was 2.404 ± 0.012 and 2.355 ± 0.009, respectively, and in phosphate buffer pH 6.8 + 1.0% SDS it was 0.051 ± 0.005 and 1.805 ± 0.023, respectively. The permeability study was assessed using the parallel artificial membrane permeability assay (PAMPA) model. The apparent permeability coefficient (Papp—cm s−1) of form I and III in pH 1.2 was 3.01 × 10−5 ± 4.14 × 10−7 and 3.15 × 10−5 ± 1.89 × 10−6, respectively, while in pH 6.8 it was 2.72 × 10−5 ± 1.56 × 10−6 and 2.81 × 10−5 ± 9.0 × 10−7, respectively. Changes in sorafenib tosylate concentrations were determined by chromatography using the high-performance liquid chromatography (HPLC)–DAD technique. As a result of the research on the structural polymorphism of sorafenib tosylate, its full spectral characteristics and the possibility of using FT-IR and Raman spectroscopy for the study of polymorphic varieties were determined for the first time, and the HPLC method was developed, which is appropriate for the assessment of sorafenib solubility in various media. The consequences of various physicochemical properties resulting from differences in the solubility of sorafenib tosylate polymorphs are important for pre-formulation and formulation studies conducted with its participation and for the safety of oncological sorafenib therapy. [ABSTRACT FROM AUTHOR]

Ti(β) alloys have become an important class in the biomedical field due to low Young's modulus, excellent physical properties, and biocompatibility. However, their properties, like biocompatibility and, also, low wear resistance, can be still enhanced. To improve those properties, a composites approach can be applied. This research shows a new approach of the composite structure fabrication by powder metallurgy methods which for a stabile yttria-stabilized zirconia (YSZ) reinforcement phase could be obtained in the ultra-fine grain range beta-titanium matrix. In this work, the composites based on ultrafine-grain Ti-xMo (x = 23 wt%, 27 wt%, 35 wt%) alloys with addition 3 wt%, 5 wt% or 10 wt% YSZ, and 1 wt% Y2O3 were fabricated by the mechanical alloying and hot-pressing approach. Obtained composites were characterized in terms of their phase composition, microstructure, Young's modulus, hardness, surface free energy (SFE), and corrosion resistance. The structure of composites consists of phases based on Ti–Mo, Ti(α), and YSZ. The oxide (YSZ) powder tends to agglomerate during processing, which is revealed in composites based on Ti23Mo and Ti27Mo. However, composites based on Ti35Mo are characterized by a high degree of dispersibility and this influences significantly the hardness value of the composites obtained. Only in the case of composites based on Ti35Mo, the decrease in Young' Modulus is observed. All composites possess a hydrophilic surface property and good corrosion resistance. [ABSTRACT FROM AUTHOR]

Hydroxyapatite (HAp) is the most widely used material for bio coating. The functional layer can be produced by many methods, however, the most perspective by its utility, easy to scale up, and simplicity aspects remains a hydrothermal treatment approach. In this work, an HAp coating was produced by low-temperature hydrothermal treatment on the ultrafine-grain beta Ti-xMo (x = 23, 27, 35 wt.%) alloys. The proposed surface treatment procedure combines acid etching, alkaline treatment (AT), and finally hydrothermal treatment (HT). The uniqueness of the approach relies on the recognition of the influence of the molar concentration of NaOH (5 M, 7 M, 10 M, 12 M) during the alkaline treatment on the growth of hydroxyapatite crystals. Obtained and modified specimens were examined structurally and microstructurally at every stage of the process. The results show that the layer after AT consist of titanium oxide and phases based on sodium with various phase relations dependent on NaOH concentration and base composition. The AT in 7 M and 10 M enables to obtain the HAp layer, which can be characterized as the most developed in terms of thickness and porosity. Finally, selected coated samples were investigated in terms of surface wettability test managed in time relation, which for the results confirm high hydrophilicity of the surfaces. Conducted research shows that the low-temperature hydrothermal processing could be considered for a possible adaptation in the drug encapsulation and delivery systems. [ABSTRACT FROM AUTHOR]

In this study, the ultrafine-grained Ti23Zr25Nb-based composites with 45S5 Bioglass and Ag, Cu, or Zn additions were produced by application of the mechanical alloying technique. Additionally, the base Ti23Zr25Nb alloy was electrochemically modified in the two stages of processing: electrochemical etching in the solution of H3PO4 and HF followed by electrochemical deposition in Ca(NO3)2, (NH4)2HPO4, and HCl. The in vitro cytocompatibility studies were also done with comparison to the commercially pure titanium. The established cell lines of Normal Human Osteoblasts (NHost, CC-2538) and Human Periodontal Ligament Fibroblasts (HPdLF, CC-7049) were used. The culture was conducted among the tested materials. Ultrafine-grained titanium-based composites modified with 45S5 Bioglass and Ag, Cu, or Zn metals have higher biocompatibility than the reference material in the form of a microcrystalline Ti. Proliferation activity was at a stable level with contact with studied materials. In vitro evaluation research showed that the ultrafine-grained Ti23Zr25Nb-based composites with 45S5 Bioglass and Ag, Cu, or Zn additions, with a Young modulus below 50 GPa, can be further used in the biomedical field. [ABSTRACT FROM AUTHOR]

Austenitic 316L steel is known for its good oxidation resistance and corrosion behavior. However, the poor wear protection is its substantial disadvantage. In this study, laser surface alloying with boron and some metallic elements was used in order to form the surface layers of improved wear behavior. The microstructure was studied using OM, SEM, XRD, and EDS techniques. The laser-alloyed layers consisted of the only re-melted zone (MZ). The hard ceramic phases (Fe2B, Cr2B, Ni2B, or Ni3B borides) occurred in a soft austenitic matrix. The relatively high overlapping (86%) resulted in a uniform thickness and homogeneous microstructure of the layers. All the laser-alloyed layers were free from defects, such as microcracks or gas pores, due to the use of relatively high dilution ratios (above 0.37). The heat-affected zone (HAZ) wasn't visible in the microstructure because of the extended stability of austenite up to room temperature and no possibility to change this structure during fast cooling. The use of the mixtures of boron and selected metallic elements as the alloying materials caused the diminished laser beam power in order to obtain the layers of acceptable quality. The thickness of laser-alloyed layers (308–432 μm) was significantly higher than that produced using diffusion boriding techniques. [ABSTRACT FROM AUTHOR]

The paper presents study results of laser alloying of CT90 tool steel with an applied pre-coat of boron, molybdenum or a mixture of these elements. Pre-coats were applied on steel substrates in the form of a paste. The aim of the study was to investigate the microstructure, chemical and phase composition, microhardness and corrosion resistance of these newly-formed coatings. The laser alloying process was carried out using a diode laser with a nominal power of 3 kW. In this study a laser beam power of 900 W and a scanning speed of 48 mm/s were used. As a result of the laser beam action, the presence of three areas was observed in cross-sections of specimens: a remelted zone, a heat affected zone and the substrate. The properties of coatings enriched with both molybdenum and boron were better than those of the steel substrate, but only the use of a Mo-B mixture resulted in a significant improvement in microhardness and corrosion resistance. [ABSTRACT FROM AUTHOR]

In this paper, binary β type Ti-23 at.% Mo alloys were obtained by arc melting as well as by mechanical alloying and powder metallurgical process with cold powder compaction and sintering or, interchangeably, hot pressing. The influence of the synthesis method on the microstructure and properties of bulk alloys were studied. The produced materials were characterized by an X-ray diffraction technique, scanning electron microscopy and chemical composition determination. Young's modulus was evaluated with nanoindentation testing method based on the Oliver and Pharr approach. The mechanically alloyed Ti-23 at.% Mo powders, after inductively hot-pressed at 800 °C for 5 min, allowed the formation of single Ti(β) phase alloy. In this case, Young's modulus and Vickers hardness were 127 GPa and 454 HV0.3, respectively. Among the examined materials, the porous (55%) single-phase scaffold showed the lowest indentation modulus (69.5 GPa). Analytical approach performed in this work focuses also on the surface properties. The estimation includes the corrosion resistance analyzed in the potentiodynamic test, and also some wettability properties as a contact angle, and surface free energy values measured in glycerol and diiodomethane testing fluids. Additionally, surface modification of processed material by micro-arc oxidation and electrophoretic deposition on the chosen samples was investigated. Proposed procedures led to the formation of apatite and fluorapatite layers, which influence both the corrosion resistance and surface wetting properties in comparison to unmodified samples. The realized research shows that a single-phase ultrafine-grained Ti-23 at.% Mo alloy for medical implant applications can be synthesized at a temperature lower than the transition point by the application of hot pressing of mechanically alloyed powders. The material processing, that includes starting powder preparation, bulk alloy transformation, and additional surface treatment functionalization, affect final properties by the obtained phase composition and internal structure. [ABSTRACT FROM AUTHOR]

For the first time, the influence of ionising radiation on the physicochemical properties of ertapenem in solid state was studied. During our studies, we evaluated the possibility of applying radiosterilization to obtain sterile ertapenem. Spectroscopic (Fourier Transform Infrared (FT-IR)), thermal (differential scanning calorimetry (DSC), chromatography (High-Performance Liquid Chromatography (HPLC) and HPLC-MS), and X-ray powder diffraction (XRPD) studies shown that irradiation of ertapenem with the 25 kGy, the dose required to achieve sterility, does not change the physicochemical properties of the studied compound. The antimicrobial activity of ertapenem irradiated with the dose of 25 kGy was only reduced for one species. Based on the received results, we can conclude that radiostelization is a promising alternative method of obtaining sterile ertapenem. In our studies, ertapenem was also exposed to e-beam radiation with a dose of 400 kGy. It was determined that two novel degradation products that are structurally differently to degradants formed during hydrolysis and thermolysis. [ABSTRACT FROM AUTHOR]

In this work, mechanical alloying and electrical current-assisted sintering was adopted for in situ metal matrix composite material processing. Applied at the initial powder stage, mechanical alloying enables a homogeneous distribution of the starting elements in the proposed precursor powder blends. The accompanying precursor preparation and the structurally confirmed size reduction allow obtainment of a nanoscale range for the objects to be sintered. The nano precursors aggregated in the micro-sized particle objects, subjected to electrical current-assisted sintering, characterize the metal matrix composite sinters with high uniformity, proper densification, and compaction response, as well as maintaining a nanoscale whose occurrence was confirmed by the appearance of the highly dispersed reinforcement phase in the examined Ti-TiB material example. The structural analysis of the sinters confirms the metal matrix composite arrangement and provides an additional quantitive data overview for the comparison of the processing conditions. The mechanical alloying examined in this work and the electrical current-assisted sintering approach allow in situ metal matrix composite structures to create their properties by careful control of the processing steps. [ABSTRACT FROM AUTHOR]

The problem of determining the formation of complexes of β-lactam antibiotics with cyclodextrins (CDs) and the interactions involved in this process were addressed by machine learning on multispectral images. Complexes of β-lactam antibiotics, including cefuroxime axetil, cefetamet pivoxil, and pivampicillin, as well as CDs, including αCD, βCD, γCD, hydroxypropyl-αCD, methyl-βCD, hydroxypropyl-βCD, and hydroxypropyl-γCD, were prepared in all combinations. Thermograms confirming the formation of cyclodextrin complexes were obtained using differential scanning calorimetry. Transmission Fourier-transform infrared (tFTIR) and complementary attenuated total reflectance FTIR (ATR) coupled with machine learning were techniques chosen as a nondestructive alternative. The machine learning algorithm was used to determine the formation of complexes in samples using solely their tFTIR and ATR spectra at the prediction stage. Parameterized method 7 (PM7) was used to support the analysis by molecular modeling of the complexes. The model developed through machine learning properly distinguished samples with formed complexes form noncomplexed samples with a cross-validation accuracy of 90.4%. Analysis of the contribution of spectral bands to the model indicated interactions of ester groups of β-lactam antibiotics with CDs, as well as some interactions of cephem ring in cefetamet pivoxil and penam moiety in pivampicillin. Molecular modeling with PM7 helped to explain experimental results and allowed to propose possible binding modes. [ABSTRACT FROM AUTHOR]

The influence of ionising radiation on the physicochemical properties of meropenem trihydrate in solid state was studied for doses of e-beam radiation: 25 kGy and 400 kGy. In the first part of our studies, we evaluated the possibility of applying radiosterilization to obtain sterile meropenem. No changes for meropenem irradiated with a dose of 25 kGy, the dose required to attain sterility, was confirmed in the results of spectroscopic (FT-IR), thermal (DSC, TGA) and X-ray powder diffraction (XRPD) studies. The radiation dose of 25 kGy produces no more than about 1500 ppm of radical defects. The chromatographic studies of irradiated meropenem in solutions did not show any chemical degradation. Moreover, the antimicrobial activity of meropenem irradiated with the dose of 25 kGy was unchanged. Based on the received results, we can conclude that radiostelization is a promising, alternative method for obtaining sterile meropenem. In the second part of the research, meropenem was exposed to e-beam radiation at the 400 kGy dose rate. It was confirmed, that reducing of antimicrobial activity could be connected with the degradation of β-lactam ring and changes in the trans-hydroxyethyl group. Apart from chemical changes, changes in the physical stability of irradiated meropenem (400 kGy) was also observed. [ABSTRACT FROM AUTHOR]

Paper presents study on the hydrothermal treatment for hydroxyapatite layer formation on the different biodegradable Mg-substrates. The evaluation of corrosion resistance in Ringer's solution and contact angle measurements in glycerol were performed. Alloys and composites substrates obtained by mechanical alloying and powder metallurgy route are characterized by submicron range microstructure, which is responsible for further surface processing characteristic. Hydrothermal treatment in Ca-EDTA (ethylenediaminetetraacetic acid calcium disodium salt) led to formation of hydroxyapatite layers, which improves both the corrosion resistance and surface wetting properties compared to microcrystalline magnesium. [ABSTRACT FROM AUTHOR]

The study was a pioneering attempt to assess the influence of the structural polymorphism (forms I, II, III) of benzocaine on its solubility, apparent solubility, and chemical stability, which are vital parameters for preformulation and formulation work. The impact of differences in the solubility of selected polymorphs of benzocaine on their permeability through artificial biological membranes (PAMPA system) was evaluated. The polymorphs of benzocaine were obtained by means of techniques commonly used for the preparation of various pharmaceutical dosage forms: ball milling, micro milling, and cryogenic grinding, which allowed for the appearance or preservation of form III, the initial conformation of benzocaine. Ball milling resulted in the conversion of form III to I, whereas micro milling yielded form II. As a result of cryogenic grinding, form III of benzocaine was preserved. The identification of all polymorphic forms of benzocaine was confirmed via X-ray powder diffraction (PXRD) supported by FT-IR spectroscopy coupled with density functional theory (DFT) calculations. The differences in solubility, dissolution, and permeability through artificial biological membranes resulting from the polymorphic forms of benzocaine were established by using chromatographic determinations. Accelerated stability tests indicated that all polymorphic forms were chemically stable at a required level. [ABSTRACT FROM AUTHOR]

In this work, NiAl-xWC (x = 0 - 90 wt.% WC) intermetallic-based composites were successfully synthesized by mechanical alloying (MA) and a hot-pressing approach. As initial powders, a mixture of nickel, aluminum and tungsten carbide was used. The phase changes in analyzed systems after mechanical alloying and hot pressing were evaluated by an X-ray diffraction method. Scanning electron microscopy and hardness test examination were used for evaluating microstructure and properties for all fabricated systems from the initial powder to the final sinter stage. The basic sinter properties were evaluated to estimate their relative densities. Synthesized and fabricated NiAl-xWC composites showed an interesting relationship between the structure of the constituting phases, analyzed by planimetric and structural methods and sintering temperature. The analyzed relationship proves that the structural order reconstructed by sintering strongly depends on the initial formulation and its decomposition after MA processing. The results confirm that it is possible to obtain an intermetallic NiAl phase after 10 h of MA. For processed powder mixtures, the results showed that increased WC content intensifies fragmentation and structural disintegration. The final structure of the sinters fabricated in lower (800 °C) and higher temperature regimes (1100 °C), consisted of recrystallized NiAl and WC phases. The macro hardness of sinters obtained at 1100 °C increased from 409 HV (NiAl) to 1800 HV (NiAl + 90% WC). Obtained results reveal a new applicable perspective in the field of intermetallic-based composites and remain highly anticipated for possible application in severe-wear or high-temperature conditions.

Titanium β-type alloys are preferred biomaterials for hard tissue replacements due to the low Young modulus and limitation of harmful aluminum and vanadium present in the commercially available Ti6Al4V alloy. The aim of this study was to develop a new ternary Ti-Zr-Nb system at 36≤Ti≤70 (at. %). The technical viability of preparing Ti-Zr-Nb alloys by high-energy ball-milling in a SPEX 8000 mill has been studied. These materials were prepared by the combination of mechanical alloying and powder metallurgy approach with cold powder compaction and sintering. Changes in the crystal structure as a function of the milling time were investigated using X-ray diffraction. Our study has shown that mechanical alloying supported by cold pressing and sintering at the temperature below α→β transus (600°C) can be applied to synthesize single-phase, ultrafine-grained, bulk Ti(β)-type Ti30Zr17Nb, Ti23Zr25Nb, Ti30Zr26Nb, Ti22Zr34Nb, and Ti30Zr34Nb alloys. Alloys with lower content of Zr and Nb need higher sintering temperatures to have them fully recrystallized. The properties of developed materials are also engrossing in terms of their biomedical use with Young modulus significantly lower than that of pure titanium., Competing Interests: The authors declare no conflicts of interest.

This study aimed to investigate changes in the solubility and antimicrobial efficacy of cefuroxime axetil (CA) when incorporated into cyclodextrin (CD). While choosing the CD, the validated in silico model was used. A theoretical model based on docking and molecular mechanics/generalized born surface area was validated using a curated dataset of API (active pharmaceutical ingredient)-CD stability constants. The library of commonly used cyclodextrins was virtually screened, indicating CA -hydroxypropyl-βCD (HPβCD) as the most thermodynamically favored system. Solid-state CA-HPβCD system was prepared and characterized by differential scanning calorimetry (DSC), Fourier-transform infrared (FT-IR), and X-ray diffraction (XRPD) methods. The dissolution profiles of the CA and its cyclodextrin system were evaluated. Microbiological activity of the CA-HPβCD inclusion system was studied based on changes in minimal inhibitory concentration (MIC) values and related to ones of the pure CA. The theoretical model was successfully validated, obtaining an average correlation with experimental data R = 0.7. The dissolution study showed significantly improved dissolution profiles of CA-HPβCD compared to CA. HPβCD increases the antimicrobial efficacy of CA up to 4-fold compared to pure CA., Competing Interests: The authors declare no conflicts of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript; or in the decision to publish the results.