Cross-linking Research Articles

Physical and Structural Properties of Chitosan–Squid Gelatin Hydrogels

The development of functional hydrogels is currently receiving great attention. In this study, a squid by-product, gelatin (SG)–acetic acid solution, was added to a commercial chitosan (CH)–acetic acid solution to develop an antioxidant hydrogel. The CH–SG mass ratios evaluated were 1:0, 2:1, and 1:2. Glutaraldehyde was used as cross linker. The effects of the SG addition to the hydrogel on different properties (physical in general, stability in aqueous media at pH 7.2, swelling, textural profile, and antioxidant) were evaluated. The interaction of CH and SG was established by scanning electron microscope microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), and nuclear magnetic resonance spectroscopy (NMR). As a result, the addition of SG decreased the resistance to flow, hardness, chewiness, and stability, but increased the springiness, resilience, and antioxidant properties of CH hydrogels. The SEM analysis revealed that the CH-GS hydrogel showed a relatively more porous structure. FTIR and NMR analyses suggested a good compatibility of the components due mainly to an increased hydrogen bond formation. The present results suggest that CH could establish a valuable interaction with SG, so that a new hydrogel with enhanced textural and antioxidant properties would be produced, which would enable its potential application in biomedical and food industries.

Evaluation of gum odina/carbopol composite mucoadhesive hydrogel on pharmaceutical performance: Focusing on potential periodontal treatment.

Antimicrobial buccal hydrogel made of polymers have gained tremendous utilisation in biomedical field. Dual drug loaded, porous materials are important areas of research for medical and pharmaceutical industries. In this regard, a series of hydrogels (F1, F2, F3) were prepared with gum odina and carbopol 940 in aqueous solution with calcium chloride as the cross linker and glycerol as plasticizer by ionotropic gelation method. The buccal hydrogel was evaluated for thermal stability (TGA/DSC) revealing them to be thermally stable. The SEM and AFM studies of the optimized formulation (F2) exhibits cracks and porous structure. It also depicted good injectability and self-healing. The XRD result displayed amorphous nature of the formulation (F2) making them soluble in buccal fluids. The chemical nature and interactions were analysed by FTIR study. The release profile portrayed controlled release patterns for amoxicillin trihydrate and fluconazole. Appreciable mucoadhesion time (6±0.7h) and strength (12.03±0.45g) was observed in case of F2. The optimized formulation F2 displayed good antifungal and antibacterial properties. Thus, it is concluded that the hydrogel formed were mucoadhesive and highly potent to carry drug molecules for controlled release in the buccal mucosa to treat several periodontal infections.

Pd nanocatalyst supported on chitosan–waste oil microspheres for efficient degradation of industrial pollutants in water

Abstract Disposal of industrial pollutants is one of the most important working topics today. Pd–doped catalysts have high efficiency in the degradation of many organic pollutants. Within the scope of this study, waste engine oil (WEO) was used as activated carbon (AC) source and then AC was encapsulated with chitosan (CS) to prepared chitosan–based microbeads (CS/WEO AC) for catalyst support. After treatment with glyoxal as cross–linker, Pd nanoparticles with spherical shape and 16.8 nm diameter were decorated on the microbeads (Pd@CS/WEO AC). Efficiency of Pd@CS/WEO AC on the reduction of 4-nitrophenol (4-NP), 4-nitro-o-phenylenediamine (4-NPDA), 2-nitroaniline (2-NA), 4-nitroaniline (4-NA) as nitroarens; methylene blue (MB), methyl orange (MO), and rhodamine B (RhB) as organic dyes; Cr(VI) and K3[Fe(CN)6] was examined in aqueous media. Developed Pd@CS/WEO AC nanocatalyst reduced nitroarenes, organic dyes, Cr(VI) and K3[Fe(CN)6] in very short times (0–130 s). Based on kinetic studies, the rate constants for Pd@CS/WEO AC–catalyzed reduction reactions of 2–NA, 4–NP, 4–NA, 4–NPDA, MO, RhB, [Fe(CN)6]3⁻, and Cr(VI) were found to be 0.018 s−1, 0.007 s−1, 0.026 s−1, 0.012 s−1, 0.021 s−1, 0.065 s−1, 0.048 s−1, and 0.042 s−1, respectively. Additionally, it was confirmed that Pd@CS/WEO AC is a long–lasting catalyst, as it was reused for five successive runs in the reduction of 4–NP. In this study, we aim to design new materials by modifying carbon–containing waste sources with biological macromolecules and investigate the possible applications of these materials to remove some pollutants from water sources.

Injectable biocompatible hydrogels with tunable strength based on crosslinked supramolecular polymer nanofibers.

Hydrogels based on supramolecular assemblies offer attractive features for biomedical applications including injectability or versatile combinations of various building blocks. We here investigate a system combining benzenetrispeptides (BTP), which forms supramolecular fibers, with polymer polyethylene oxide (PEO) forming a dense hydrophilic shell around the fibers. Hydrogels are created through the addition of a bifunctional crosslinker (CL). Rheological studies revealed that shorter hydrophobic n-hexyl spacers (BTP-C6) lead to stronger hydrogels than BTP-C12 comprising n-dodecyl chains. All hydrogels recovered rapidly (<5 s) after deformation in step-strain-measurements. We varied the crosslinker content between 0.1, 1 and 10 mol% and the overall concentration of the gelator. While the shear storage modulus of all BTP-C12 hydrogels remains below 1 kPa independent of the variations, the shear storage modulus of BTP-C6 hydrogels can be tuned from around 0.2 kPa up to almost 8 kPa. Shear rate dependent viscosity measurements further revealed similar shear thinning behavior of all hydrogels, and the calculation of extrusion parameters confirmed that the hydrogels can be easily injected even through thin cannulae. Accordingly, we injected a fluorescein-containing BTP-C6 sample into chicken breast demonstrating the potential for application as an injectable drug depot. Furthermore, BTP-C6 hydrogels prevent the adherence of L929 mouse fibroblasts but preserve their relative metabolic activity (>87%) during incubation on the gel when compared to cells growing on adherent surfaces. Our investigations overall reveal that the BTP-C6 system in particular has attractive features for applications in tissue engineering or as an injectable and biocompatible drug depot.

Guar Gum Hydrogel as a Biosorbent for Cd(II) and Cu(II) Ions: Kinetic, Equilibrium, and Thermodynamic Insights

AbstractThe effectiveness of modified guar gum (Cyamopsis tetragonoloba) as a Cd(II) and Cu(II) adsorbent in aquatic media was investigated. Synthesis of modified guar gum based on copolymerization with 2‐Acrylamido‐2‐methyl‐1‐propane sulfonic acid and acrylamide in presence of methylene bis‐acrylamide as a cross linker and in the form of hydrogel adsorbent. Various analytical techniques were employed to describe the surface morphology of the modified adsorbent. Adsorption tests were carried out under different conditions of adsorbent dose (10–50 mg), Cd(II) and Cu(II) initial concentration (25–150 mg/L), pH (1.0–7.0), temperature (∼25–55 °C), and time (∼15–120 min). The maximum uptakes (88 and 82 mg/g) were achieved at pH 6.0 and 5.0 for cadmium (II) and copper (II) ions, respectively. For both metal ions, the kinetics data for the adsorption process obeyed a pseudo second‐order rate equation (R2 = 0.9814 and 0.9845, respectively). The adsorption isotherm data were described using 3 models. Thermodynamic parameters such as enthalpy (∆H), entropy (∆S), and Gibbs free energy (∆G) changes were calculated. Cadmium and copper ions adsorption on modified guar gum was discovered to be endothermic and non‐spontaneous. For both metal ions, 5 M HCl and 1 M EDTA were utilized as de‐sorbents, with the latter having a higher desorption efficiency. The prepared hydrogel was proved as an effective promising adsorbent at capturing cadmium and copper ions from laboratory wastewaters and it could be used for further treatment of other effluent wastes.

HE USE OF CROSS LINKER IN UPHOLSTERY LEATHER FINISHING COATING

Leather upholstery must have good rub resistance, adhesion, and flexing resistance to be able for a long time. This study aims to determine the correct amount of cross linker use to obtain the good rub resistance, adhesion, and flexing resistance upholstery of the leather upholstery finishing coat. Crust leather, adhesive solvent, diluent solvent, penetrator, medium light polyurethane, light polyurethane, aliphatic polyurethane, cross linker, spray gun, flex meter, rubbing fastness tester, and grey scale are used as material. Upholstery leather finishing consist of base, medium and top coat. The method is addition of 2, 3, and 4% cross linker from the total of top coat composition. The result of wet rubbing resistance test are very faded (value=1) when using 2% cross linker, medium faded (value=3) when using 3% cross linker, very no faded (value=5) when using 4% cross linker. The dry rubbing resistance of each treatment showed no difference. Adhesion value (≤12.0 N) and flexing resistance (no crack) for all treatment met the requirement. It can be concluded that the use of a cross linker of 4% in the top coat finishing produces the best test value.

Adsorption Optimization of VNi‐Layered Double Hydroxide Encapsulated With Chitosan and Carboxymethyl Cellulose for Rhodamine B Dye Removal From Aqueous Solutions: Adsorption Isotherm, Kinetics, and Thermodynamics

ABSTRACTIndustrial dye–contaminated wastewater needs creative techniques to effectively remove these contaminants. An easy co‐precipitation technique was used in this work to create the VNi‐layered double hydroxide (VNi‐LDH) adsorbent. VNi‐LDH was encapsulated with chitosan (CS) and carboxymethyl cellulose (CMC) that cross‐linked with itaconic acid as the cross linker via chemical crosslinking to form VNi‐LDH/CS‐CMC hydrogel beads. FT‐IR, SEM, XPS, BET, XRD, BET, and point of zero charge (pHzpc) were employed to characterize the prepared material. Examining VNi‐LDH/CS‐CMC's ability to remove rhodamine B (RB) from water waste as an adsorbent was the aim of the study. The highest adsorption capacity of RB on VNi‐LDH/CS‐CMC was found to be 653.8 mg/g. The research findings designated that the Langmuir isotherm models provided the most accurate representation of the RB adsorption procedure for VNi‐LDH/CS‐CMC. At a dosage of 0.8 g/L for the adsorbent and an equilibrium time of 100 min, it was established that the RB adsorption of VNi‐LDH/CS‐CMC hydrogel beads occurred at a pH of 8. The model of pseudo‐second order, demonstrating chemisorption with an adsorption energy of 30.34 kJ/mol along with a diffusion‐limited adsorption process, was most appropriate for the RB adsorption kinetics on VNi‐LDH/CS‐CMC hydrogel beads. The impact of temperature was also investigated, with an analysis of the thermodynamic variables (∆H°, ∆S°, and ∆G°) revealing a spontaneous increase in positive enthalpy and entropy charge, along with a decrease in ΔG°, as the temperature rose. The adsorption process outcomes were further optimized using response surface methodology (RSM) and the Box–Behnken design (BBD). It was proposed that the elimination of RB through VNi‐LDH/CS‐CMC may occur through different potential mechanisms, such as chemisorption, pore‐filling, π‐π bonding, electrostatic interactions, and hydrogen bonding. Given that the adsorbent was made of reusable materials and could be reused more than six times with high efficiency, the VNi‐LDH/CS‐CMC hydrogel beads offer a viable low‐cost option for removing RB dye from wastewater streams.

The novel DNA cross-linking agent KL-50 is active against patient-derived models of new and recurrent post-temozolomide mismatch repair-deficient glioblastoma.

Acquired resistance to temozolomide (TMZ) chemotherapy due to DNA mismatch repair (MMR) enzyme deficiency is a barrier to improving outcomes for IDH wild-type glioblastoma (GBM) patients. KL-50 is a new imidazotetrazine-based therapeutic designed to induce DNA interstrand cross links, and subsequent double-stranded breaks, in an MMR-independent manner in cells with O-6-Methylguanine-DNA Methyltransferase (MGMT) deficiency. Previous research showed its efficacy against LN229 glioma cells with MMR and MGMT knockdown. Its activity against patient-derived GBM that model post-TMZ recurrent tumors is unclear. We created MMR-deficient GBM patient-derived xenografts through exposure to TMZ, followed by treatment with additional TMZ or KL-50. We also generated isogenic, MSH6 knockout patient-derived GBM and tested them for sensitivity to TMZ and KL-50. KL-50 extended the median survival of mice intracranially engrafted with either patient-derived TMZ-naïve GBM6 or TMZ-naïve GBM12 by 1.75-fold and 2.15-fold, respectively (p<0.0001). A low dose (4 Gy) of fractionated RT further extended the survival of KL-50 treated GBM12 mice (median survival=80 days for RT+ KL-50 vs. 71 days KL-50 alone, P=0.018). KL-50 also extended the median survival of mice engrafted with post-TMZ, MMR-deficient GBM6R-m185 (140 days for KL-50 vs. 37 days for vehicle, p<0.0001). MSH6-KO increased TMZ IC50 for GBM6 and GBM12 cultures by >5-fold and >12-fold for cell death and live cell count outputs, respectively. In contrast, MSH6-KO actually decreased KL-50 IC50 by 10-80%. KL-50-based compounds are a promising new strategy for the treatment of MGMT-deficient, MMR-deficient GBM that recurs after frontline TMZ.

Synthesis of pH-sensitive ternary hydrogel with synergetic antibacterial response for the release of ampicillin sodium

In the area of biomedicine, pH-responsive hydrogels have attracted a lot of attention. The smart novel polyelectrolyte complex carriers are made of chitosan, gum arabic and polyvinylpyrrolidone using various concentrations of ratan-jot plant extract for the release of sodium ampicillin antibiotic very first time. These hydrogels have been prepared by solution casting method and cross-linked by using 3-aminopropyldiethoxymethyl silane. According to swelling experiments, the cross linker concentration led to decreased swelling because the hydrogels were more tightly packed together. CPG-3A showed maximum swelling 54.5 g/g in 210 min. When the swelling behaviour of hydrogels was tested under various pH circumstances, it was found that they swelled most noticeably in alkaline media and least noticeably in acidic and neutral pH settings. These hydrogels may be appropriate for injection-based controlled drug release due to their unique pH-responsive behaviour. Ampicillin sodium salt was utilised as a model drug to analyse drug release behaviour of engineered hydrogel at pH 7.4. The results indicate that these smart hydrogels could be used for injectable controlled drug release (ampicillin sodium) for the treatment of wound as well as for other biomedical applications.

Synchronously strengthening and plasticizing of unsaturated polyester resin based on styrene-maleic anhydride oligomer

To synchronously strength and plasticize unsaturated polyester resin (UPR), maleic anhydride were directly added in the unsaturated polyester resin solution and form the styrene-maleic anhydride oligomer (SMAO) without initiation. The creating SMAO cross link with UPR by curing reaction, and the prepared UPR resin exhibit higher tensile, elongation, bending strength and higher impact strength simultaneously, 0.45, 0.36, 0.76 and 0.12 times than UPR matrix, SMAO-UPR exhibits obvious plastic fracture characteristics; The DSC result indicates that the curing degree of SMAO-UPR is 96.55% which is 1.45% lower than that of UPR; The TG result indicates that MA and St mainly form an alternating copolymer below 90°C. The SEM and DMA result indicates that SMAO improves the morphology and structure which shows plastic deformation of UPR, and there is a certain interface effect between SMAO and UPR. Compared with the traditional method of large molecular weight SMA modified UPR, this method of reinforcing UPR is better for mechanical property, easy to operate, inexpensive, and highly applicable in industrial production.

Sodium Alginate/Poly (Acrylicacid) Hydrogel Composite, Potential Carrier for Fibroblast Growth Factor1 (FGF1) Delivery.

Fibroblast growth factor1 is a powerful signaling molecule that plays a critical role in injury repair of diverse tissue by stimulating cell growth and angiogenesis. FGF1 has significant role in the cell fate and regulating inflammation with short half-life and poor in vivo stability. The encapsulation of the growth factor in the hydrogel led to peptide protect from the degradation and/or immune recognition and enable controlled drug delivery over a longer period of time. The aim of this study is to develop and evaluate a hydrogel carrier with adjustable release rate while maintaining bioactivity of FGF1. Here we describe an optimal ratio of sodium alginate and polyacrylic acid without additional cross linker containing optimum amount of FGF1 with the potential of sustained release to be used as a therapeutic agent. The carrier was characterized by FTIR, contact angle and swelling ratio. The activity of FGF1 after release from the hydrogel was confirmed by ELISA and Western blot. Further assessment of genes related to inflammation were evaluated by RTPCR. This hydrogel is able to deliver growth factors by restricting the essential proteins within the matrix to prevent rapid proteolysis and explosive release and is therefore widely applicable.

Cross-linked Arenga pinnata (Wurmb.) Merr. starch and chitosan with sodium trimetaphosphate: Structure, physicochemical properties and in vitro digestibility.

The inherent limitations of native starch considerably restrict its applications in the food industry. To enhance its processing properties, Arenga pinnata (Wurmb.) Merr. starch (APS) was subjected to dual modification with low levels of sodium trimetaphosphate (0%, 1%, and 3%) and chitosan (1%) to investigate its physicochemical, thermal, pasting, and in vitro digestibility. The dual modification of APS significantly increased the degree of cross-linked (CLD) to 84.69%, resulting in a rougher surface texture. This process led to the formation of phosphate bonds, the weakening of hydrogen bonds, and a decrease in relative crystallinity, all while preserving the starch's crystalline structure. Additionally, the modification impeded paste formation, reduced swelling power, and lowered pasting enthalpy, while increasing the content of slowly digestible starch and resistant starch. These findings provided a basis to enhance the functional properties of starch-based materials, which could be applied to improve the texture and stability of food products such as sauces, dressings, and desserts in the food industry.

Fabrication of ion imprinted graphene oxide-chitosan membrane cross linked by self polymerized polydopamine for selective adsorption of La(III)

Recovery of rare earths from secondary sources tallies with environmental remediation and sustainable exploitation of rare earth resources simultaneously. Herein, La(III) imprinted graphene oxide-chitosan membrane cross linked by self polymerized PDA (IIP-GO-CS-PDA) was constructed via using CS as functional monomer, PDA as cross linker and La(III) as template. The as constructed IIP-GO-CS-PDA was elaborately characterized in terms of crystallinity, morphology, chemical structure, porosity and thermal stability. Subsequently, adsorption efficiency and selective recovery performance of IIP-GO-CS-PDA towards La(III) were evaluated via batch adsorption. Result indicates, adsorption of La(III) by IIP-GO-CS-PDA is induced by electrostatic interaction, thereby reaching maximum adsorption efficiency at pH = 5. Functional groups C-O, C-N, −C(=O)–NH, –NH2 in IIP-GO-CS-PDA provides heterogeneous affinity for La(Ⅲ), inducing chemical adsorption. Adsorption proceeds rapidly to reach equilibrium in 30 min, manifesting impressive efficiency. The maximum adsorption capacity determined by Langmuir fitting is 275.48 mg·g−1. By virtue of its ion imprinting sites, IIP-GO-CS-PDA demonstrates selectivity coefficients 3.20, 3.34, 8.68, 9.28, 9.43, 9.58 towards La(Ⅲ) for binary solutions La/Eu, La/Dy, La/Cr, La/Cu, La/Cd, La/Pb, respectively. Owing to its membrane configuration, IIP-GO-CS-PDA can be easily recovered for cyclic adsorption, whereby retaining adsorption quantity 91.72 mg·g−1 for La(Ⅲ) in five consecutive cycles. Compared with other adsorbents, IIP-GO-CS-PDA exhibits rapid equilibrium, superior adsorption capacity and selectivity towards La(Ⅲ). This work provides a novel solution for fabricating bio adsorbent towards selective recovery of La(Ⅲ).

Tuning the properties of peptide imprinted nanoparticles for protein immunoprecipitation using magnetic streptavidin beads

Maximizing the binding properties of thermoresponsive molecularly imprinted nanoparticles (MIN) was aimed to explore their feasibility as antibody substitutes in protein immunoprecipitation (IPP) with magnetic streptavidin beads (MSB). Thermoresponsive MIN targeting the cannabinoid CB1 receptor were produced by epitope imprinting through solid-phase synthesis. It was intended to determine how different variables influenced physicochemical features, binding behaviour and immunoprecipitation of the target recombinant glutathione S-transferase tagged fusion protein (GST-CTer). Such variables included the cross-linking degree of MIN, and variables like pH, temperature or the use of Tween-20 for binding and IPP experiments. The cross-linker (CL) amount influenced the coil-to-globule transition of thermoresponsive MIN, making the lower critical solution temperature (LCST) decrease from 37.2 °C using 5% of CL, to 29.0 °C using 25%, also suggesting higher plasticity on the former. Temperature influence on size was corroborated by dynamic light scattering, observing size reductions from 250–450 nm (RT) to 70–100 nm (> LCST) for MIN produced with 5–15% of CL. However, binding behaviour did not clearly improve for more than 10% CL. Further experiments revealed that temperature and pH control were critical for efficient binding and release, selecting 40 °C and pH 5 as appropriate. Following binding experiments, the GST-CTer-MIN complex was successfully immunoprecipitated using MSB, achieving an IPP efficiency of 11.48% over the initial input protein concentration, which was calculated after SDS-PAGE separation and Western blot analysis. The methodology may be exploited for selective protein extraction and quantification from complex tissue homogenates.Graphical

Transforming Small-Scale Farm Entrepreneurship Through Innovation: the Case of Cross Link

The study focuses on the critical role of innovation, education, and technology in fostering agricultural entrepreneurship among youth, particularly in Sub-Saharan Africa. The research highlights the challenges and opportunities encountered in the intersection of traditional agricultural practices and modern technology. The purpose of the research is to bridge the gap in literature regarding young agricultural entrepreneurs in Ghana, providing a detailed case study that could serve as motivation for other aspiring small-scale farmers. The paper investigates the factors that contributed to the success of Cross Link Farms, including the educational background, networking, and mentorship received by the entrepreneur, as well as the practical application of innovative technologies such as smart incubators and hydroponic systems. This case-paper demonstrates the importance of entrepreneurial education that instilled a passion in a student to become the co-founder of a farm entrepreneurship startup. The paper applied a case study approach; data were collected through the usage of interview. The interview was recorded and transcribed. The data were analyzed interpretively. The main conclusions emphasize that innovation and technology, when coupled with a strong educational foundation and support system, are vital in transforming agriculture in Ghana and similar regions. Cross Link Farms serves as a model for how young entrepreneurs can leverage these elements to drive change, enhance food security, and contribute to rural development. The findings suggest that targeted policies and programs that foster entrepreneurial innovation in agriculture are essential for sustainable development in Sub-Saharan Africa. Based on the case-study findings, recommendations for future research include conducting empirical studies involving entrepreneurs in sub-Saharan countries to assess the role of curiosity, resilience and passion in their entrepreneurship journey.

Enzymatic Insitu Crosslinking Can Improve Hydrogel Stability While Maintaining Matrix Stiffness

AbstractNext to the choice of a material, the crosslinking characteristics play an important role in the development of hydrogels for applications in the biomedical field. By decreasing crosslinking time or concentration one can reduce the density of the network and hence the stiffness of the hydrogel. However, at the same time in many cases the stability of the matrix is significantly reduced, leading to a rapidly degrading hydrogel structure. In this study, we evaluate and compare two different crosslinking methods while maintaining the material chemistry. The hydrogel system evaluated consisted of oxidized hyaluronic acid and gelatin, and it was crosslinked with microbial transglutaminase. We found that by in situ crosslinking (CL) instead of post CL we can significantly increase the stability of the hydrogel while maintaining the matrix stiffness. Encapsulated embryonic mouse fibroblasts showed an increased viability in in situ crosslinked samples. These findings indicate that it is possible to change hydrogel parameters independently, even if they are otherwise interrelated.

Functionalised Sodium-Carboxymethylcellulose-Collagen Bioactive Bilayer as an Acellular Skin Substitute for Future Use in Diabetic Wound Management: The Evaluation of Physicochemical, Cell Viability, and Antibacterial Effects.

The wound healing mechanism is dynamic and well-orchestrated; yet, it is a complicated process. The hallmark of wound healing is to promote wound regeneration in less time without invading skin pathogens at the injury site. This study developed a sodium-carboxymethylcellulose (Na-CMC) bilayer scaffold that was later integrated with silver nanoparticles/graphene quantum dot nanoparticles (AgNPs/GQDs) as an acellular skin substitute for future use in diabetic wounds. The bilayer scaffold was prepared by layering the Na-CMC gauze onto the ovine tendon collagen type 1 (OTC-1). The bilayer scaffold was post-crosslinked with 0.1% (w/v) genipin (GNP) as a natural crosslinking agent. The physical and chemical characteristics of the bilayer scaffold were evaluated. The results demonstrate that crosslinked (CL) groups exhibited a high-water absorption capacity (>1000%) and an ideal water vapour evaporation rate (2000 g/m2 h) with a lower biodegradation rate and good hydrophilicity, compression, resilience, and porosity than the non-crosslinked (NC) groups. The minimum inhibitory concentration (MIC) of AgNPs/GQDs presented some bactericidal effects against Gram-positive and Gram-negative bacteria. The cytotoxicity tests on bilayer scaffolds demonstrated good cell viability for human epidermal keratinocytes (HEKs) and human dermal fibroblasts (HDFs). Therefore, the Na-CMC bilayer scaffold could be a potential candidate for future diabetic wound care.

Thermomechanical properties of multifunctional polymer hybrid nanocomposites based on carbon nanotubes and nanosilica

AbstractNanocomposites containing low wt% of oxidized multi‐walled carbon nanotubes (MWCNT‐OXI), nanosilica (NS), and its hybrid (MWCNT‐OXI/NS) in epoxy resin were produced and evaluated. The used nanoparticles were studied by scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and Raman spectroscopy while the nanocomposites were investigated in relation to its morphology, thermal, and mechanical properties. The results demonstrated significant improvements in the storage modulus (E′), glass transition temperature (Tg), and cross link density (CD), for the produced nanocomposites. Increases in thermal conductivity (TC) of up to 85% at 90°C were observed for the nanocomposites containing 1.0 wt% of the hybrid MWCNT‐OXI + NS nanofiller, when compared with neat polymer. It was also verified increases in the resistance to plastic deformation for the nanocomposites, maintained the polymer thermal stability with the addition of these nanoparticles. Finally, the use of MWCNT‐OXI and NS, combined or not, significantly improved the thermal and mechanical properties of polymer, showing multifunctional characteristics for the produced nanocomposites.

LC-MS metabolomics and lipidomics in cerebrospinal fluid from viral and bacterial CNS infections: a review.

There is compelling evidence that a dysregulated immune inflammatory response in neuroinfectious diseases results in modifications in metabolic processes and altered metabolites, directly or indirectly influencing lipid metabolism within the central nervous system (CNS). The challenges in differential diagnosis and the provision of effective treatment in many neuroinfectious diseases are, in part, due to limited understanding of the pathophysiology underlying the disease. Although there are numerous metabolomics studies, there remains a deficit in neurolipidomics research to provide a comprehensive understanding of the connection between altered metabolites and changes in lipid metabolism. The brain is an inherently high-lipid organ; hence, understanding neurolipidomics is the key to future breakthroughs. This review aims to provide an integrative summary of altered cerebrospinal fluid (CSF) metabolites associated with neurolipid metabolism in bacterial and viral CNS infections, with a particular focus on studies that used liquid chromatography-mass spectrometry (LC-MS). Lipid components (phospholipids) and metabolites (carnitine and tryptophan) appear to be the most significant indicators in both bacterial and viral infections. On the basis of our analysis of the literature, we recommend employing neurolipidomics in conjunction with existing neurometabolomics data as a prospective method to enhance our understanding of the cross link between dysregulated metabolites and lipid metabolism in neuroinfectious diseases.

Tartrate-resistant acid phosphatase (TRAP/ACP5) promotes bone length, regulates cortical and trabecular bone mass, and maintains growth plate architecture and width in a sex- and site-specific manner in mice

Tartrate-resistant acid phosphatase (TRAP) serum levels reflect osteoclast number, bone remodeling activity, and fracture risk. Deletion or loss of function of TRAP results in short stature in mice and man. Yet, the impact and mechanisms of TRAP for the site- and sex-specific development of bone and cartilage is not well understood. Here, we use a global TRAP knockout (TRAPKO) and wildtype littermate control (WT) mice of both sexes to investigate TRAP as a possible sex- and site-specific regulator of bone and growth plate development. TRAPKO mice of both sexes weighed less and had shorter tibial length than their WT, features that were more accentuated in male than female TRAPKO mice. These changes were not associated with a general reduction in growth as not all organs displayed a proportionally lower mass, and serum IGF-1 was unchanged. Using μCT and site-specificity analysis of the cortical bone revealed wider proximal tibia, a higher trabecular thickness, and lower trabecular separation in male TRAPKO compared to WT mice, an effect not seen in female mice. Histomorphometric analysis revealed that the growth plate height as well as height of terminal hypertrophic chondrocytes were markedly increased, and the number of columns was decreased in TRAPKO mice of both sexes. These effects were more accentuated in female mice. Proliferation and differentiation of bone marrow derived macrophages into osteoclasts, as well as C-terminal cross links were normal in TRAPKO mice of both sexes. Collectively, our results show that TRAP regulates bone and cartilage development in a sex-and site-specific manner in mice.