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Summary: This study sheds light upon how the decomposition of cabbage waste (CW) is brought to make it capable of providing bioenergy along with bio‐chemicals. The CW is evaporated through three steps, and at the same time, non‐condensable products (NH3, CO2, CH4, CO, SO2 and NO) and condensable products like (H2O, CH3CH2OH, CH3COOH, CC, C6H5OH and HCOOH) are yielded. The products that have gone through the pyrolysis process comprise 45% condensable products. Thermogravimetry‐Fourier transform infrared (TG‐FTIR) analysis shows that lower temperature can be more effective for condensable products formation from CW as compared to higher temperature. Pyrolysis gas chromatography (Py/GC‐MS) confirms presence of the high energy and value‐added chemical compounds such as toluene, benzene and phenols among pyrolytic products. According to initial reports, liquid pyrolytic products produce more than 70% energy. All these results demonstrate that CW could be promising source of bioenergy and valuable bio‐chemicals production via pyrolysis. [ABSTRACT FROM AUTHOR]

The goal of this study was to explore a route for introducing functionalities into agarose-based hydrogels to tune the physical, chemical, and biological properties. Several agarose derivatives were prepared by homogeneous synthesis, including anionic agarose sulfates (ASs), reactive azido agaroses (AZAs), and cationic agarose carbamates (ACs), as well as agarose tosylates (ATOSs) and agarose phenyl carbonates (APhCs). The products were characterized in terms of their molecular structure and solubility behavior. The results suggest that the native gel-forming ability of agarose is retained if the introduced functionalities are hydrophilic, and the overall degree of substitution is low (DS < 0.5). Thus, functional hydrogels from several agarose derivatives could be obtained. The mechanical stability of the functional hydrogels was decreased compared to native agarose gels but was still in a range that enables safe handling. An increase in mechanical strength could be achieved by blending functional agarose derivatives and agarose into composite hydrogels. Finally, it was demonstrated that the novel functional agarose hydrogels are biocompatible and can potentially stimulate interactions with cells and tissue. [ABSTRACT FROM AUTHOR]

When optimizing the process parameters of the acidic ethanolic organosolv process, the aim is usually to maximize the delignification and/or lignin purity. However, process parameters such as temperature, time, ethanol and catalyst concentration, respectively, can also be used to vary the structural properties of the obtained organosolv lignin, including the molecular weight and the ratio of aliphatic versus phenolic hydroxyl groups, among others. This review particularly focuses on these influencing factors and establishes a trend analysis between the variation of the process parameters and the effect on lignin structure. Especially when larger data sets are available, as for process temperature and time, correlations between the distribution of depolymerization and condensation reactions are found, which allow direct conclusions on the proportion of lignin's structural features, independent of the diversity of the biomass used. The newfound insights gained from this review can be used to tailor organosolv lignins isolated for a specific application. [ABSTRACT FROM AUTHOR]

This research studies in detail four different assays, namely DPPH (2,2-diphenyl-1-picrylhydrazyl), ABTS (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)), FRAP (ferric ion reducing antioxidant potential) and FC (Folin-Ciocalteu), to determine the antioxidant capacity of standard substances as well as 50 organosolv lignins, and two kraft lignins. The coefficient of variation was determined for each method and was lowest for ABTS and highest for DPPH. The best correlation was found for FRAP and FC, which both rely on a single electron transfer mechanism. A good correlation between ABTS, FRAP and FC, respectively, could be observed, even though ABTS relies on a more complex reaction mechanism. The DPPH assay merely correlates with the others, implying that it reflects different antioxidative attributes due to a different reaction mechanism. Lignins obtained from paulownia and silphium have been investigated for the first time regarding their antioxidant capacity. Paulownia lignin is in the same range as beech wood lignin, while silphium lignin resembles wheat straw lignin. Miscanthus lignin is an exception from the grass lignins and possesses a significantly higher antioxidant capacity. All lignins possess a good antioxidant capacity and thus are promising candidates for various applications, e. g. as additives in food packaging or for biomedical purposes. [Display omitted] • Determination of reproducibility and sensitivity of 4 assays using standards • Strongly positive correlations between FRAP, FC and ABTS assays of 52 lignins • Both HAT and SET based assays are required to assess lignin antioxidant capacity. • Miscanthus lignins resemble hardwood lignins rather than other grasses. [ABSTRACT FROM AUTHOR]

More than 23 million tonnes of lignin are produced annually in the US from wood pulping and 98% of this lignin is burnt. Therefore, creating products from lignin, such as plastics, offers an approach for obtaining sustainable materials in a circular economy. Lignin-based copolymers were synthesized using a single pot, solvent free, melt condensation reaction. The synthesis occurred in two stages. In the first stage, a biobased prepolymer consisting of butanediol (BD, 0.8–1 molar content) and a diacid (succinic (SA), adipic (AA) and suberic acids (SuA), with varying amounts of diaminobutane (DAB, 0–0.2 molar content) was heated under vacuum and monitored by Fourier transform infra-red (FTIR) spectroscopy and electrospray ionization-mass spectrometry (ESI-MS). In the second stage, prepolymer was mixed with a softwood kraft lignin (0–50 wt.%) and further reacted under vacuum at elevated temperature. Progression of the polymerization reaction was monitored using FTIR spectroscopy. The lignin-copolyester/amide properties were characterized using tensile testing, X-ray diffraction (XRD), dynamic mechanical analysis (DMA), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) techniques. Lignin co-polymer tensile (strength 0.1–2.1 MPa and modulus 2 to 338 MPa) properties were found to be influenced by the diacid chain length, lignin, and DAB contents. The lignin-copolymers were shown to be semi-crystalline polymer and have thermoplastic behavior. The SA based copolyesters/amides were relatively stiff and brittle materials while the AA based copolyesters/amides were flexible and the SuA based copolyesters/amides fell in-between. Additionally, > 30 wt.% lignin the lignin- copolyesters/amides did not exhibit melt behavior. Lignin-co-polyester/amides can be generated using green synthesis methods from biobased building blocks. The lignin- copolyesters/amides properties could be tuned based on the lignin content, DAB content and diacid chain length. This approach shows that undervalued lignin can be used in as a macromonomer in producing thermoplastic materials. [ABSTRACT FROM AUTHOR]

The need for bone grafts is high, due to age-related diseases, such as tumor resections, but also accidents, risky sports, and military conflicts. The gold standard for bone grafting is the use of autografts from the iliac crest, but the limited amount of accessible material demands new sources of bone replacement. The use of mesenchymal stem cells or their descendant cells, namely osteoblast, the bone-building cells and endothelial cells for angiogenesis, combined with artificial scaffolds, is a new approach. Mesenchymal stem cells (MSCs) can be obtained from the patient themselves, or from donors, as they barely cause an immune response in the recipient. However, MSCs never fully differentiate in vitro which might lead to unwanted effects in vivo. Interestingly, purinergic receptors can positively influence the differentiation of both osteoblasts and endothelial cells, using specific artificial ligands. An overview is given on purinergic receptor signaling in the most-needed cell types involved in bone metabolism—namely osteoblasts, osteoclasts, and endothelial cells. Furthermore, different types of scaffolds and their production methods will be elucidated. Finally, recent patents on scaffold materials, as wells as purinergic receptor-influencing molecules which might impact bone grafting, are discussed. [ABSTRACT FROM AUTHOR]

Apart from the characterization of impurities, the full characterization of heparin and low molecular weight heparin (LMWH) also requires the determination of average molecular weight, which is closely related to the pharmaceutical properties of anticoagulant drugs. To determine average molecular weight of these animal-derived polymer products, partial least squares regression (PLS) was utilized for modelling of diffused-ordered spectroscopy NMR data (DOSY) of a representative set of heparin (n = 32) and LMWH (n = 30) samples. The same sets of samples were measured by gel permeation chromatography (GPC) to obtain reference data. The application of PLS to the data led to calibration models with root mean square error of prediction of 498 Da and 179 Da for heparin and LMWH, respectively. The average coefficients of variation (CVs) did not exceed 2.1% excluding sample preparation (by successive measuring one solution, n = 5) and 2.5% including sample preparation (by preparing and analyzing separate samples, n = 5). An advantage of the method is that the sample after standard 1D NMR characterization can be used for the molecular weight determination without further manipulation. The accuracy of multivariate models is better than the previous results for other matrices employing internal standards. Therefore, DOSY experiment is recommended to be employed for the calculation of molecular weight of heparin products as a complementary measurement to standard 1D NMR quality control. The method can be easily transferred to other matrices as well. [ABSTRACT FROM AUTHOR]

Lignin is a promising renewable biopolymer being investigated worldwide as an environmentally benign substitute of fossil-based aromatic compounds, e.g. for the use as an excipient with antioxidant and antimicrobial properties in drug delivery or even as active compound. For its successful implementation into process streams, a quick, easy, and reliable method is needed for its molecular weight determination. Here we present a method using 1H spectra of benchtop as well as conventional NMR systems in combination with multivariate data analysis, to determine lignin's molecular weight (M w and M n) and polydispersity index (PDI). A set of 36 organosolv lignin samples (from Miscanthus x giganteus, Paulownia tomentosa and Silphium perfoliatum) was used for the calibration and cross validation, and 17 samples were used as external validation set. Validation errors between 5.6% and 12.9% were achieved for all parameters on all NMR devices (43, 60, 500 and 600 MHz). Surprisingly, no significant difference in the performance of the benchtop and high-field devices was found. This facilitates the application of this method for determining lignin's molecular weight in an industrial environment because of the low maintenance expenditure, small footprint, ruggedness, and low cost of permanent magnet benchtop NMR systems. • 1H NMR spectroscopy (43 – 600 MHz) was used to model the molecular weight of lignin. • PLS regression models were developed and validated. • Equally good performance was achieved for benchtop and high-field devices. [ABSTRACT FROM AUTHOR]

Osteoporosis is a chronical, systemic skeletal disorder characterized by an increase in bone resorption, which leads to reduced bone density. The reduction in bone mineral density and therefore low bone mass results in an increased risk of fractures. Osteoporosis is caused by an imbalance in the normally strictly regulated bone homeostasis. This imbalance is caused by overactive bone-resorbing osteoclasts, while bone-synthesizing osteoblasts do not compensate for this. In this review, the mechanism is presented, underlined by in vitro and animal models to investigate this imbalance as well as the current status of clinical trials. Furthermore, new therapeutic strategies for osteoporosis are presented, such as anabolic treatments and catabolic treatments and treatments using biomaterials and biomolecules. Another focus is on new combination therapies with multiple drugs which are currently considered more beneficial for the treatment of osteoporosis than monotherapies. Taken together, this review starts with an overview and ends with the newest approaches for osteoporosis therapies and a future perspective not presented so far. [ABSTRACT FROM AUTHOR]

Dental stem cells have been isolated from the medical waste of various dental tissues. They have been characterized by numerous markers, which are evaluated herein and differentiated into multiple cell types. They can also be used to generate cell lines and iPSCs for long-term in vitro research. Methods for utilizing these stem cells including cellular systems such as organoids or cell sheets, cell-free systems such as exosomes, and scaffold-based approaches with and without drug release concepts are reported in this review and presented with new pictures for clarification. These in vitro applications can be deployed in disease modeling and subsequent pharmaceutical research and also pave the way for tissue regeneration. The main focus herein is on the potential of dental stem cells for hard tissue regeneration, especially bone, by evaluating their potential for osteogenesis and angiogenesis, and the regulation of these two processes by growth factors and environmental stimulators. Current in vitro and in vivo publications show numerous benefits of using dental stem cells for research purposes and hard tissue regeneration. However, only a few clinical trials currently exist. The goal of this review is to pinpoint this imbalance and encourage scientists to pick up this research and proceed one step further to translation. [ABSTRACT FROM AUTHOR]

The lignocellulosic biomass is comprised of three major components: cellulose, hemicellulose, and lignin. Among these three, cellulose and hemicellulose were already used for the generation of simple sugars and subsequent value-added products. However, lignin is the least applied material in this regard because of its complex and highly variable nature. Regardless, lignin is the most abundant material, and it can be used to produce value-added products such as lignin-modifying enzymes (LMEs), polyhydroxyalkanoates (PHAs), microbial lipids, vanillin, muconic acid, and many others. This review explores the potential of lignin as the microbial substrate to produce such products. A special focus was given to the different types of lignin and how each one can be used in different microbial and biochemical pathways to produce intermediate products, which can then be used as the value-added products or base to make other products. This review paper will summarize the effectiveness of lignin as a microbial substrate to produce value-added products through microbial fermentations. First, basic structures of lignin along with its types and chemistry are discussed. The subsequent sections highlight LMEs and how such enzymes can enhance the value of lignin by microbial degradation. A major focus was also given to the value-added products that can be produced from lignin. [ABSTRACT FROM AUTHOR]

As a low-input crop, Miscanthus offers numerous advantages that, in addition to agricultural applications, permits its exploitation for energy, fuel, and material production. Depending on the Miscanthus genotype, season, and harvest time as well as plant component (leaf versus stem), correlations between structure and properties of the corresponding isolated lignins differ. Here, a comparative study is presented between lignins isolated from M. x giganteus, M. sinensis, M. robustus and M. nagara using a catalyst-free organosolv pulping process. The lignins from different plant constituents are also compared regarding their similarities and differences regarding monolignol ratio and important linkages. Results showed that the plant genotype has the weakest influence on monolignol content and interunit linkages. In contrast, structural differences are more significant among lignins of different harvest time and/or season. Analyses were performed using fast and simple methods such as nuclear magnetic resonance (NMR) spectroscopy. Data was assigned to four different linkages (A: β-O-4 linkage, B: phenylcoumaran, C: resinol, D: β-unsaturated ester). In conclusion, A content is particularly high in leaf-derived lignins at just under 70% and significantly lower in stem and mixture lignins at around 60% and almost 65%. The second most common linkage pattern is D in all isolated lignins, the proportion of which is also strongly dependent on the crop portion. Both stem and mixture lignins, have a relatively high share of approximately 20% or more (maximum is M. sinensis Sin2 with over 30%). In the leaf-derived lignins, the proportions are significantly lower on average. Stem samples should be chosen if the highest possible lignin content is desired, specifically from the M. x giganteus genotype, which revealed lignin contents up to 27%. Due to the better frost resistance and higher stem stability, M. nagara offers some advantages compared to M. x giganteus. Miscanthus crops are shown to be very attractive lignocellulose feedstock (LCF) for second generation biorefineries and lignin generation in Europe. [ABSTRACT FROM AUTHOR]

Lignin nanomaterials have wide application prospects in the fields of cosmetics delivery, energy storage, and environmental governance. In this study, we developed a simple and sustainable synthesis approach to produce uniform lignin nanoparticles (LNPs) by dissolving industrial lignin in deep eutectic solvents (DESs) followed by a self-assembling process. LNPs with high yield could be obtained through nanoprecipitation. The LNPs were characterized by dynamic light scattering (DLS), transmission electron microscopy (TEM), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and gel permeation chromatography (GPC). Distinct LNPs could be produced by changing the type of DES, lignin sources, pre-dropping lignin concentration, and the pH of the system. Their diameter is in the range of 20–200 nm and they show excellent dispersibility and superior long-term stability. The method of preparing LNPs from lignin–DES with water as an anti-solvent is simple, rapid, and environmentally friendly. The outcome aids to further the advancement of lignin-based nanotechnology. [ABSTRACT FROM AUTHOR]

The extraction and characterization of defined and carboxyl-rich oligomeric lignin fragments with narrow molecular weight distribution is presented herein. With regard to the well-known pulp bleaching process, oxidative lignin depolymerization was investigated using hydrogen peroxide in an aqueous alkaline solution (i.e., at T = 318 K, t = 1 h) and subsequent selective fractionation with a 10/90 (v/v) acetone/water mixture. While the weight average molecular weight (MW) of lignin in comparison to the starting material was reduced by 82% after oxidation (T = 318 K, t = 1 h, clignin = 40 g L−1, cH2O2 = 80 g L−1, cNaOH = 2 mol L−1) and subsequent solvent fractionation (T = 298 K, t = 18 h, ccleavage product = 20 g L−1), the carboxyl group (–COOH) content increased from 1.29 mmol g−1 up to 2.66 mmol g−1. Finally, the successful scale-up of this whole process to 3 L scale led to gram amounts (14% yield) of oligomeric lignin fragments with a MW of 1607 g mol−1, a number average molecular weight (MN) of 646 g mol−1, a narrow polydispersity index of 3.0, and a high –COOH content of 2.96 mmol g−1. Application of these oligomeric lignin fragments in epoxy resins or as adsorbents is conceivable without further functionalization. [ABSTRACT FROM AUTHOR]

Ionic liquids (ILs) based on 1-butyl-3-methylimidazolium (bmim) cation have proved to be promising solvents for the fractionation of plant biomass with the production of cellulose and lignin. This study deals with the characterization of lignins isolated from coniferous (spruce) wood using [bmim]OAc and [bmim]MeSO4 ionic liquids and their binary mixtures with DMSO (80:20). Molecular weight distributions, functional composition, and structural features of IL lignins were studied by size-exclusion chromatography, NMR spectroscopy (1D and 2D) and atmospheric pressure photoionization high-resolution mass spectrometry. It was shown that the interaction of ILs with lignin leads to significant chemical changes in the biopolymer; a decrease in the degree of polymerization and in the content of free phenolic hydroxyl groups due to alkylation, the disappearance (in the case of [bmim]OAc) of carbonyl groups and a significant destruction of β-O-4 bonds. The chemical reactions between lignin and 1-butyl-3-methylidazolium cation with covalent binding of ionic liquids or products of their decomposition is evidenced by the presence of a large number of nitrogen-containing oligomers in IL lignins. [ABSTRACT FROM AUTHOR]

With increasing life expectancy, demands for dental tissue and whole-tooth regeneration are becoming more significant. Despite great progress in medicine, including regenerative therapies, the complex structure of dental tissues introduces several challenges to the field of regenerative dentistry. Interdisciplinary efforts from cellular biologists, material scientists, and clinical odontologists are being made to establish strategies and find the solutions for dental tissue regeneration and/or whole-tooth regeneration. In recent years, many significant discoveries were done regarding signaling pathways and factors shaping calcified tissue genesis, including those of tooth. Novel biocompatible scaffolds and polymer-based drug release systems are under development and may soon result in clinically applicable biomaterials with the potential to modulate signaling cascades involved in dental tissue genesis and regeneration. Approaches for whole-tooth regeneration utilizing adult stem cells, induced pluripotent stem cells, or tooth germ cells transplantation are emerging as promising alternatives to overcome existing in vitro tissue generation hurdles. In this interdisciplinary review, most recent advances in cellular signaling guiding dental tissue genesis, novel functionalized scaffolds and drug release material, various odontogenic cell sources, and methods for tooth regeneration are discussed thus providing a multi-faceted, up-to-date, and illustrative overview on the tooth regeneration matter, alongside hints for future directions in the challenging field of regenerative dentistry. [ABSTRACT FROM AUTHOR]

Micro- and nanosize lignin shows improved properties compared to standard lignin available today and has been gaining interest in recent years. Lignin is the largest renewable resource with an aromatic skeleton on earth but it is used for relatively low-value applications. Lignin in micro- to nanoscale; however, could facilitate rather valuable applications. Current production methods consume high amounts of solvents for purification and precipitation. The process investigated in this work uses the direct precipitation of lignin nanoparticles from organosolv pretreatment extract in a static mixer and can reduce solvent consumption drastically. The pH value, ratio of antisolvent to organosolv extract and flowrate in the mixer were investigated as precipitation parameters in terms of the resulting particle properties. Particles with dimensions ranging from 97.3 to 219.3 nm could be produced, and at certain precipitation parameters, carbohydrate impurities reach values as low as in purified lignin particles. Yields were found independent of the precipitation parameters with 48.2 ± 4.99%. Results presented in this work can be used to optimize precipitation parameters with emphasis on particle size, carbohydrate impurities or the solvent consumption. [ABSTRACT FROM AUTHOR]

A large-scale glycol lignin (GL) production process (50 kg wood meal per batch) based on acid-catalyzed polyethylene glycol (PEG) solvolysis of Japanese cedar (JC) was developed at the Forestry and Forest Products Research Institute (FFPRI), Tsukuba, Japan. JC wood meal with various particle size distributions (JC-S < JC-M < JC-L) (average meal size, JC-S (0.4 mm) < JC-M (0.8 mm) < JC-L (1.6 mm)) and liquid PEG with various molecular masses are used as starting materials to produce PEG-modified lignin derivatives, namely, GLs, with various physicochemical and thermal properties. Because GLs are considered a potential feedstock for industrial applications, the effect of heat treatment on GL properties is an important issue for GL-based material production. In this study, GLs obtained from PEG400 solvolysis of JC-S, JC-M, and JC-L were subjected to heating in a constant-temperature drying oven at temperatures ranging from 100 to 220 °C for 1 h. All heat-treated GL series were thermally stable, as determined from the Klason lignin content, TMA, and TGA analyses. SEC analysis suggests the possibility of condensation among lignin fragments during heat treatment. ATR-FTIR spectroscopy, thioacidolysis, and 2D HSQC NMR demonstrated that a structural rearrangement occurs in the heat-treated GL400 samples, in which the content of α–PEG-β–O-4 linkages decreases along with the proportional enrichments of β–5 and β–β linkages, particularly at treatment temperatures above 160 °C. [ABSTRACT FROM AUTHOR]

Bone tissue engineering is an ever-changing, rapidly evolving, and highly interdisciplinary field of study, where scientists try to mimic natural bone structure as closely as possible in order to facilitate bone healing. New insights from cell biology, specifically from mesenchymal stem cell differentiation and signaling, lead to new approaches in bone regeneration. Novel scaffold and drug release materials based on polysaccharides gain increasing attention due to their wide availability and good biocompatibility to be used as hydrogels and/or hybrid components for drug release and tissue engineering. This article reviews the current state of the art, recent developments, and future perspectives in polysaccharide-based systems used for bone regeneration. [ABSTRACT FROM AUTHOR]

Healing of large bone defects requires implants or scaffolds that provide structural guidance for cell growth, differentiation, and vascularization. In the present work, an agarose-hydroxyapatite composite scaffold was developed that acts not only as a 3D matrix, but also as a release system. Hydroxyapatite (HA) was incorporated into the agarose gels in situ in various ratios by a simple procedure consisting of precipitation, cooling, washing, and drying. The resulting gels were characterized regarding composition, porosity, mechanical properties, and biocompatibility. A pure phase of carbonated HA was identified in the scaffolds, which had pore sizes of up to several hundred micrometers. Mechanical testing revealed elastic moduli of up to 2.8 MPa for lyophilized composites. MTT testing on Lw35human mesenchymal stem cells (hMSCs) and osteosarcoma MG-63 cells proved the biocompatibility of the scaffolds. Furthermore, scaffolds were loaded with model drug compounds for guided hMSC differentiation. Different release kinetic models were evaluated for adenosine 5′-triphosphate (ATP) and suramin, and data showed a sustained release behavior over four days. [ABSTRACT FROM AUTHOR]

Nowadays, regenerative medicine has paid special attention to research (in vitro and in vivo) related to bone regeneration, specifically in the treatment of bone fractures or skeletal defects, which is rising worldwide and is continually demanding new developments in the use of stem cells, growth factors, membranes and scaffolds based on novel nanomaterials, and their applications in patients by using advanced tools from molecular biology and tissue engineering. Strontium (Sr) is an element that has been investigated in recent years for its participation in the process of remodeling and bone formation. Based on these antecedents, this is a review about the Strontium Folate (SrFO), a recently developed non-protein based bone-promoting agent with interest in medical and pharmaceutical fields due to its improved features in comparison to current therapies for bone diseases. [ABSTRACT FROM AUTHOR]

The antiradical and antimicrobial activity of lignin and lignin-based films are both of great interest for applications such as food packaging additives. The polyphenolic structure of lignin in addition to the presence of O-containing functional groups is potentially responsible for these activities. This study used DPPH assays to discuss the antiradical activity of HPMC/lignin and HPMC/lignin/chitosan films. The scavenging activity (SA) of both binary (HPMC/lignin) and ternary (HPMC/lignin/chitosan) systems was affected by the percentage of the added lignin: the 5% addition showed the highest activity and the 30% addition had the lowest. Both scavenging activity and antimicrobial activity are dependent on the biomass source showing the following trend: organosolv of softwood > kraft of softwood > organosolv of grass. Testing the antimicrobial activities of lignins and lignin-containing films showed high antimicrobial activities against Gram-positive and Gram-negative bacteria at 35 °C and at low temperatures (0–7 °C). Purification of kraft lignin has a negative effect on the antimicrobial activity while storage has positive effect. The lignin release in the produced films affected the activity positively and the chitosan addition enhances the activity even more for both Gram-positive and Gram-negative bacteria. Testing the films against spoilage bacteria that grow at low temperatures revealed the activity of the 30% addition on HPMC/L1 film against both B. thermosphacta and P. fluorescens while L5 was active only against B. thermosphacta. In HPMC/lignin/chitosan films, the 5% addition exhibited activity against both B. thermosphacta and P. fluorescens. [ABSTRACT FROM AUTHOR]

Bioinspired stem cell-based hard tissue engineering includes numerous aspects: The synthesis and fabrication of appropriate scaffold materials, their analytical characterization, and guided osteogenesis using the sustained release of osteoinducing and/or osteoconducting drugs for mesenchymal stem cell differentiation, growth, and proliferation. Here, the effect of silicon- and silicate-containing materials on osteogenesis at the molecular level has been a particular focus within the last decade. This review summarizes recently published scientific results, including material developments and analysis, with a special focus on silicon hybrid bone composites. First, the sources, bioavailability, and functions of silicon on various tissues are discussed. The second focus is on the effects of calcium-silicate biomineralization and corresponding analytical methods in investigating osteogenesis and bone formation. Finally, recent developments in the manufacturing of Si-containing scaffolds are discussed, including in vitro and in vivo studies, as well as recently filed patents that focus on the influence of silicon on hard tissue formation. [ABSTRACT FROM AUTHOR]

As a renewable, Miscanthus offers numerous advantages such as high photosynthesis activity (as a C4 plant) and an exceptional CO2 fixation rate. These properties make Miscanthus very attractive for industrial exploitation, such as lignin generation. In this paper, we present a systematic study analyzing the correlation of the lignin structure with the Miscanthus genotype and plant portion (stem versus leaf). Specifically, the ratio of the three monolignols and corresponding building blocks as well as the linkages formed between the units have been studied. The lignin amount has been determined for M. x giganteus (Gig17, Gig34, Gig35), M. nagara (NagG10), M. sinensis (Sin2), and M. robustus (Rob4) harvested at different time points (September, December, and April). The influence of the Miscanthus genotype and plant component (leaf vs. stem) has been studied to develop corresponding structure-property relationships (i.e., correlations in molecular weight, polydispersity, and decomposition temperature). Lignin isolation was performed using non-catalyzed organosolv pulping and the structure analysis includes compositional analysis, Fourier transform infradred (FTIR), ultraviolet/visible (UV-Vis), hetero-nuclear single quantum correlation nuclear magnetic resonsnce (HSQC-NMR), thermogravimetric analysis (TGA), and pyrolysis gaschromatography/mass spectrometry (GC/MS). Structural differences were found for stem and leaf-derived lignins. Compared to beech wood lignins, Miscanthus lignins possess lower molecular weight and narrow polydispersities (<1.5 Miscanthus vs. >2.5 beech) corresponding to improved homogeneity. In addition to conventional univariate analysis of FTIR spectra, multivariate chemometrics revealed distinct differences for aromatic in-plane deformations of stem versus leaf-derived lignins. These results emphasize the potential of Miscanthus as a low-input resource and a Miscanthus-derived lignin as promising agricultural feedstock. [ABSTRACT FROM AUTHOR]

The aim of this study was to elucidate the impact of autologous umbilical cord blood cells (USSC) on bone regeneration and biomechanical stability in an ovine tibial bone defect. Ovine USSC were harvested and characterized. After 12 months, full-size 2.0 cm mid-diaphyseal bone defects were created and stabilized by an external fixateur containing a rigidity measuring device. Defects were filled with (i) autologous USSC on hydroxyapatite (HA) scaffold (test group), (ii) HA scaffold without cells (HA group), or (iii) left empty (control group). Biomechanical measures, standardized X-rays, and systemic response controls were performed regularly. After six months, bone regeneration was evaluated histomorphometrically and labeled USSC were tracked. In all groups, the torsion distance decreased over time, and radiographies showed comparable bone regeneration. The area of newly formed bone was 82.5 ± 5.5% in the control compared to 59.2 ± 13.0% in the test and 48.6 ± 2.9% in the HA group. Labeled cells could be detected in lymph nodes, liver and pancreas without any signs of tumor formation. Although biomechanical stability was reached earliest in the test group with autologous USSC on HA scaffold, the density of newly formed bone was superior in the control group without any bovine HA. [ABSTRACT FROM AUTHOR]

Antioxidant activity is an essential aspect of oxygen-sensitive merchandise and goods, such as food and corresponding packaging, cosmetics, and biomedicine. Technical lignin has not yet been applied as a natural antioxidant, mainly due to the complex heterogeneous structure and polydispersity of lignin. This report presents antioxidant capacity studies completed using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. The influence of purification on lignin structure and activity was investigated. The purification procedure showed that double-fold selective extraction is the most efficient (confirmed by ultraviolet-visible (UV/Vis), Fourier transform infrared (FTIR), heteronuclear single quantum coherence (HSQC) and 31P nuclear magnetic resonance spectroscopy, size exclusion chromatography, and X-ray diffraction), resulting in fractions of very narrow polydispersity (3.2–1.6), up to four distinct absorption bands in UV/Vis spectroscopy. Due to differential scanning calorimetry measurements, the glass transition temperature increased from 123 to 185 °C for the purest fraction. Antioxidant capacity is discussed regarding the biomass source, pulping process, and degree of purification. Lignin obtained from industrial black liquor are compared with beech wood samples: antioxidant activity (DPPH inhibition) of kraft lignin fractions were 62–68%, whereas beech and spruce/pine-mixed lignin showed values of 42% and 64%, respectively. Total phenol content (TPC) of the isolated kraft lignin fractions varied between 26 and 35%, whereas beech and spruce/pine lignin were 33% and 34%, respectively. Storage decreased the TPC values but increased the DPPH inhibition. [ABSTRACT FROM AUTHOR]

Renewable resources are gaining increasing interest as a source for environmentally benign biomaterials, such as drug encapsulation/release compounds, and scaffolds for tissue engineering in regenerative medicine. Being the second largest naturally abundant polymer, the interest in lignin valorization for biomedical utilization is rapidly growing. Depending on its resource and isolation procedure, lignin shows specific antioxidant and antimicrobial activity. Today, efforts in research and industry are directed toward lignin utilization as a renewable macromolecular building block for the preparation of polymeric drug encapsulation and scaffold materials. Within the last five years, remarkable progress has been made in isolation, functionalization and modification of lignin and lignin-derived compounds. However, the literature so far mainly focuses lignin-derived fuels, lubricants and resins. The purpose of this review is to summarize the current state of the art and to highlight the most important results in the field of lignin-based materials for potential use in biomedicine (reported in 2014–2018). Special focus is placed on lignin-derived nanomaterials for drug encapsulation and release as well as lignin hybrid materials used as scaffolds for guided bone regeneration in stem cell-based therapies. [ABSTRACT FROM AUTHOR]