Rice Straw Biochar and Magnetic Rice Straw Biochar for Safranin O Adsorption from Aqueous Solution

This study investigates the adsorption of Safranin O (SO) from aqueous solution by both biochar and magnetic biochar derived from rice straw. Rice straw biochar (RSB) was made by pyrolysis in a furnace at 500 °C, using a heating rate of 10 °C·min−1 for 2 h in an oxygen-limited environment, whilst the magnetic rice straw biochar (MRSB) was produced via the chemical precipitation of Fe2+ and Fe3+. The physicochemical properties of the synthesized biochars were characterized using SEM, SEM- EDX, XRD, FTIR techniques, and N2 adsorption (77 K) and pHpzc measurements. Batch adsorption experiments were used to explore the effect of pH, biochar dosage, kinetics, and isotherms on the adsorption of SO. Experimental data of RSB and MRSB fit well into both Langmuir and Freundlich isotherm models, and were also well-explained by the Lagergren pseudo-second-order kinetic model. The maximum SO adsorption capacity of MRSB was found to be 41.59 mg/g, while for RSB the figure was 31.06 mg/g. The intra-particle diffusion model indicated that the intra-particle diffusion may not be the only rate-limiting step. The collective physical and chemical forces account for the adsorption mechanism of SO molecules by both RSB and MRSB adsorbents. The obtained results demonstrated that the magnetic biochar can partially enhance the SO adsorption capacity of its precursor biochar and also be easily separated from the solution by using an external magnet.

HDAC4 mutant represses chondrocyte hypertrophy by locating in the nucleus and attenuates disease progression of posttraumatic osteoarthritis

Background The aim of this study was to evaluate whether histone deacetylase 4 S246/467/632A mutant (m-HDAC4) has enhanced function at histone deacetylase 4 (HDAC4) to attenuate cartilage degeneration in a rat model of osteoarthritis (OA). Methods Chondrocytes were infected with Ad-m-HDAC4-GFP or Ad-HDAC4-GFP for 24 h, incubated with interleukin-1β (IL-1β 10 ng/mL) for 24 h, and then measured by RT-qPCR. Male Sprague-Dawley rats (n = 48) were randomly divided into four groups and transduced with different vectors: ACLT/Ad-GFP, ACLT/Ad-HDAC4-GFP, ACLT/Ad-m-HDAC4-GFP, and sham/Ad-GFP. All rats received intra-articular injections 48 h after the operation and every 3 weeks thereafter. Cartilage damage was assessed using radiography and Safranin O staining and quantified using the OARSI score. The hypertrophic and anabolic molecules were detected by immunohistochemistry and RT-qPCR. Results M-HDAC4 decreased the expression levels of Runx-2, Mmp-13, and Col 10a1, but increased the levels of Col 2a1 and ACAN more effectively than HDAC4 in the IL-1β-induced chondrocyte OA model; upregulation of HDAC4 and m-HDAC4 in the rat OA model suppressed Runx-2 and MMP-13 production, and enhanced Col 2a1 and ACAN synthesis. Stronger Safranin O staining was detected in rats treated with m-HDAC4 than in those treated with HDAC4. The resulting OARSI scores were lower in the Ad-m-HDAC4 group (5.80 ± 0.45) than in the Ad-HDAC4 group (9.67 ± 1.83, P = 0.045). The OARSI scores were highest in rat knees that underwent ACLT treated with Ad-GFP control adenovirus vector (14.93 ± 2.14, P = 0.019 compared with Ad-HDAC4 group; P = 0.003 compared with Ad-m-HDAC4 group). Lower Runx-2 and MMP-13 production, and stronger Col 2a1 and ACAN synthesis were detected in rats treated with m-HDAC4 than in those treated with HDAC4. Conclusions M-HDAC4 repressed chondrocyte hypertrophy and induced chondrocyte anabolism in the nucleus. M-HDAC4 was more effective in attenuating articular cartilage damage than HDAC4.

Investigation of environmental and therapeutic applications of holmium doped titanium dioxide (Ho-TiO2) nanocatalysts. Kinetic and thermodynamic study of the photocatalytic degradation of Safranin O dye

Titanium dioxide (TiO2) and Holmium doped Titanium dioxide(Ho-TiO2) nanoparticles (NPs) were synthesized through Sol Gel method. The synthesized NPs were characterized by UV-Vis spectroscopy, X-ray diffraction (XRD), Energy dispersive X-ray analysis (EDX), Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and Photoluminescence spectroscopy. DNA binding, antibacterial, hemolytic and antioxidant assays of the synthesized nanoparticles were also carried out for finding their therapeutic applications. Successful doping of TiO2 with Ho reduced the band gap from 3.10 to 2.88 eV. SEM and XRD analysis showed that both TiO2 and Ho-TiO2 NPs exhibit tetragonal structure and as a result of doping the morphology of the particles improved and agglomeration reduced. PL emission intensity of TiO2 also reduced with doping.The holmium doped TiO2 were used for the first time against the degradation of Safranin O dye, DNA binding study and biocompatibility assay.The degradation of Safranin O dye over both the catalysts followed first order kinetics. The calculated activation energies for the photo degradation of given dye were found to be 51.7 and 35.2 kJ/mol using TiO2 and Ho-TiO2 NPs respectively. At 180 minutes time interval 84 and 87% dye degradation was observed using pure TiO2 and Ho-TiO2 NPs respectively. High percent degradation of dye was found at low concentration (20 ppm) and at optimal dosage (0.035 g) of both the catalysts. The rate of Safranin O dye degradation was found to increase with increase in temperature and pH of the medium. DNA binding study revealed that Ho-TiO2 NPs are more capable of binding to human DNA. Antibacterial activity study showed that Ho-TiO2 NPs were more efficient against both gram-negative and gram-positive bacterial strains as compared to pure TiO2. Hemolysis assay showed that TiO2 and Ho-TiO2 nanoparticles are non-biocompatible.Ho-TiO2 nanoparticles showed higher anti-oxidant activity as compared to bare TiO2.

Investigation of Environmental and Therapeutic Applications of Holmium doped Titanium dioxide (Ho-TiO2) nanocatalysts. Kinetic and Thermodynamic study of the Photocatalytic degradation of Safranin O dye

Titanium dioxide (TiO2) and Holmium doped Titanium dioxide(Ho-TiO2) nanoparticles (NPs) were synthesized through Sol Gel method. The synthesized NPs were characterized by UV-Vis spectroscopy, X-ray diffraction (XRD), Energy dispersive X-ray analysis (EDX), Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and Photoluminescence spectroscopy. DNA binding, antibacterial, hemolytic and antioxidant assays of the synthesized nanoparticles were also carried out for finding their therapeutic applications. Successful doping of TiO2 with Ho reduced the band gap from 3.10 to 2.88 eV. SEM and XRD analysis showed that both TiO2 and Ho-TiO2 NPs exhibit tetragonal structure and as a result of doping the morphology of the particles improved and agglomeration reduced. PL emission intensity of TiO2 also reduced with doping.The holmium doped TiO2 were used for the first time against the degradation of safranin O dye, DNA binding study and biocompatibility assay.The degradation of Safranin Odye over both the catalysts followed first order kinetics. The calculated activation energies for the photo degradation of given dye were found to be 51.7 and 35.2kJ/mol using TiO2 and Ho-TiO2 NPs respectively. At 180 minutes time interval 84% and 87 % dye degradation was observed using pure TiO2 and Ho-TiO2 NPs respectively. High percent degradation of dye was found at low concentration (20ppm) and at optimal dosage (0.035g) of both the catalysts. The rate of Safranin O dye degradation was found to increase with increase in temperature and pH of the medium. DNA binding study revealed that Ho-TiO2 NPs are more capable of binding to human DNA. Antibacterial activity study showed that Ho-TiO2 NPs were more efficient against both gram-negative and gram-positive bacterial strains as compared to pure TiO2. Hemolysis assay showed that TiO2 and Ho-TiO2 nanoparticles are non-biocompatible.Ho-TiO2 nanoparticles showed higher anti-oxidant activity as compared to bare TiO2.

Chondrocyte Adipogenic Differentiation in Softening Osteoarthritic Cartilage

A chondrocyte-to-osteoblast lineage continuum exists in the growth plate. Adipogenic differentiation of chondrocytes in vivo should be investigated. Here, unilateral anterior crossbite (UAC), which can induce osteoarthritic lesions in the temporomandibular joint (TMJ), was applied to 6-wk-old C57BL/6 mice. Matrix loss in TMJ cartilage was obvious, as demonstrated by safranin O staining, and the condylar cartilage elastic modulus values, detected by using atomic force microscopy (AFM), were reduced, indicating cartilage softening that might be linked with loss of the highly charged proteoglycan. By crossing the Rosa26/tdTomato (TdT) mice with Sox9;CreERT2 mice or with Col10;CreERT2 mice, we obtained the Sox9-TdT and Col10-TdT strains, respectively, in which the Sox9- or Col10-expressing cells, accordingly, were labeled by TdT. A few TdT-labeled cells in both strains expressed AdipoQ or DMP-1. The Sox9-TdT+AdipoQ+ cells were primarily located in the deep zone cartilage and then in the whole cartilage. Col10-TdT+AdipoQ+ cells, Sox9-TdT+DMP-1+ cells, and Col10-TdT+DMP-1+ cells were located in the deep zone region. UAC promoted AdipoQ and DMP-1 expression in cartilage. The percentages of Sox9-TdT+AdipoQ+ and Col10-TdT+AdipoQ+ cells to Sox9-TdT+ and Col10-TdT+ cells, respectively, were increased (both P < 0.05), implying that more chondrocytes were undergoing adipogenic differentiation in the UAC group, the cartilage of which was softened. The percentages of Sox9-TdT+DMP-1+ and Col10-TdT+DMP-1+ cells to Sox9-TdT+ cells and Col10-TdT+ cells, respectively, were increased (both P < 0.05), consistent with our report that UAC enhanced deep zone cartilage calcification, causing stiffening of the deep zone cartilage. Our present data demonstrated that TMJ chondrocyte descendants can become adipogenic in vivo in addition to becoming osteogenic. This potential was promoted in osteoarthritic cartilage, in which deep zone cartilage calcification-associated cartilage stiffening and proteoglycan loss-associated cartilage softening were both stimulated.

Tanshinone IIA improves degranulation of mast cells and allergic rhinitis induced by ovalbumin by inhibiting the PLCγ1/PKC/IP3R pathway

Allergic rhinitis (AR) is a common allergic inflammatory and chronic reactive disease caused by allergen-induced immunoglobulin E (IgE). Tanshinone IIA (Tan IIA) is one of the active ingredients in Salvia miltiorrhiza Bunge (Danshen) and plays a vital role in inhibiting inflammation. Thus, we hypothesized that Tan IIA has anti-allergic effects and studied the function of Tan IIA in mast cells and an AR animal model. We induced RBL-2H3 cell sensitization with monoclonal anti-2,4,6-dinitrophenyl-immunoglobulin (Ig) E/human serum albumin (DNP-IgE/HSA) and constructed an ovalbumin (OVA)-induced AR model in mice. The role of Tan IIA in AR progression was studied using the MTT assay, ELISA, western blot, toluidine blue staining, HE staining, and Alcian blue and safranin O (A&S) staining. Tan IIA treatment significantly increased IgE/HSA-induced cell viability. However, Tan IIA treatment markedly downregulated the expression levels of β-hexosaminidase, histamine, tumor necrosis factor (TNF-α), interleukin 1β (IL-1β), IL-4, and IL-5 in IgE/HSA-induced cells. Furthermore, Tan IIA improved typical symptoms in the OVA-induced AR model mice by inhibiting the phospholipase Cγ1 (PLCγ1)/protein kinase C (PKC)/IP3R pathway. Additionally, Tan IIA effectively improved the degranulation of RBL-2H3 cells and OVA-induced AR in mice. Together, these results suggest that Tan IIA may be a potential drug for the treatment of AR in the future.

Repairing Cartilage with Processed Chondrocyte Constructs: A 6-Month Study Using a Porcine Model

Objective Autologous chondrocyte implantation was the first cell-based therapy that used a tissue engineering process to repair cartilage defects. Recently improved approaches and tissue-engineered cell constructs have been developed for growing patient populations. We developed a chondrocyte construct using a collagen gel and sponge scaffold and physicochemical stimuli, implanted with a surgical adhesive. We conducted a proof-of-concept study of these improvements using a cartilage defect model in miniature swine. Design We implanted the autologous chondrocyte constructs into full-thickness chondral defects in the femoral condyle, compared those results with empty and acellular scaffold controls, and compared implantation techniques with adhesive alone and with partial adhesive with suture. Two weeks after the creation of the defects and implantation of the cellular or acellular constructs, we arthroscopically confirmed that the implanted constructs remained at the chondral defects. We evaluated the regenerated tissue macro- and microscopically 6 months after the cell constructs were implanted. The tissues were stained with Safranin-O and evaluated using Sellers’ histology grading system. Results The defects implanted with processed cell constructs and acellular scaffolds were filled with chondrocyte-like round cells and with nearly normal tissue architecture that were significantly greater degree compared to empty defect control. Even with the adhesive alone and with suture alone, the cell construct was composed of the dense cartilaginous matrix that was found in the implantation using both the sutures and the adhesive. Conclusion Implantation of cell constructs promoted regeneration and integration of articular cartilage at chondral defects in swine by 6 months.

The regulation of cell wall lignification and lignin biosynthesis during pigmentation of winter jujube

Fruit lignification is due to lignin deposition in the cell wall during cell development. However, there are few studies on the regulation of cell wall lignification and lignin biosynthesis during fruit pigmentation. In this study, we investigated the regulation of cell wall lignification and lignin biosynthesis during pigmentation of winter jujube. The cellulose content decreased, while the lignin content increased in the winter jujube pericarp during pigmentation. Safranin O-fast green staining showed that the cellulose content was higher in the cell wall of winter jujube prior to pigmentation, whereas the lignin in the cell wall increased after pigmentation. The thickness of the epidermal cells decreased with pericarp pigmentation. A combined metabolomics and transcriptomics analysis showed that guaiacyl-syringyl (G-S) lignin was the main lignin type in the pericarp of winter jujube, and F5H (LOC107424406) and CCR (LOC107420974) were preliminarily identified as the key genes modulating lignin biosynthesis in winter jujube. Seventeen MYB and six NAC transcription factors (TFs) with potential regulation of lignin biosynthesis were screened out based on phylogenetic analysis. Three MYB and two NAC TFs were selected as candidate genes and further studied in detail. Arabidopsis ectopic expression and winter jujube pericarp injection of the candidate genes indicated that the MYB activator (LOC107425254) and the MYB repressor (LOC107415078) control lignin biosynthesis by regulating CCR and F5H, while the NAC (LOC107435239) TF promotes F5H expression and positively regulates lignin biosynthesis. These findings revealed the lignin biosynthetic pathway and associated genes during pigmentation of winter jujube pericarp and provide a basis for further research on lignin regulation.

Intra-articular injection of loaded sPL sustained-release microspheres inhibits osteoarthritis and promotes cartilaginous repairs

Background Osteoarthritis is a chronic inflammatory disease of the joints associated with significant morbidity and lower quality of life. Current treatment strategies focus on reducing cartilage degeneration but fail to restore their proliferative ability. Super-activated platelet lysate (sPL) is an enhanced form of platelet-rich plasma that can be easily inactivated. The purpose of this study is to evaluate whether sPL-loaded PLGA/chitosan/gelatin microspheres can prevent and treat osteoarthritis. Methods Features of biological microspheres were detected by SEM and ELISA. Osteoarthritis chondrocytes were co-cultured with hydrogel loaded with sPL. The effect of biological microspheres on chondrocyte proliferation was evaluated using a CCK-8 cell proliferation test. Cell morphology and cell necrosis were measured with a microscope. The gene expression levels of cartilage-related markers type 2 collagen, aggrecan (ACAN), and SRY type high mobility group box-9 (SOX9) were determined by real-time quantitative polymerase chain reaction (Rt-PCR). A rat osteoarthritis model was established. Micro-CT was used to characterize cartilaginous changes after the injection of biological microspheres. Histopathological HE staining, Safranin-O Fast Green staining and staining scores, type II collagen staining, and proteoglycan staining were used to evaluate the degree of cartilaginous repair. Results Biological microspheres were able to continuously release biological factors. Exposure to loading sPL microspheres significantly increased chondrocyte proliferation, reduced cell necrosis, and increased the expression of cartilage markers type 2 collagen, ACAN, and SOX9 in osteoarthritic chondrocytes. In vivo experiments found that biological microspheres also smoothen cartilage surfaces, promote the expression of proteoglycan and type 2 collagen while also increasing cartilaginous integrity as evaluated using Safranin-O Fast Green staining. Conclusions PLGA/chitosan/gelatin hydrogel loaded with sPL is a promising tool for effective and non-invasive articular cartilage repair in osteoarthritis. Graphic abstract Biological microspheres loaded with sPL release various biological factors to promote chondrocyte proliferation and upregulate chondrocyte functionalization genes (SOX9, CoX II, ACAN), leading to an overall enhanced cartilaginous matrix.