SHOU4/4L link cell wall cellulose synthesis to pattern-triggered immunity.

Pattern recognition receptors (PRRs) are plasma membrane-localised proteins that sense molecular patterns to initiate pattern-triggered immunity (PTI). Receptor-like cytoplasmic kinases (RLCKs) function downstream of PRRs to propagate signal transduction via the phosphorylation of substrate proteins. The identification and characterisation of RLCK-regulated substrate proteins are critical for our understanding of plant immunity. We showed that SHOU4 and SHOU4L are rapidly phosphorylated upon various patterns elicitation and are indispensable for plant resistance to bacterial and fungal pathogens. Protein-protein interaction and phosphoproteomic analysis revealed that BOTRYTIS-INDUCED KINASE 1, a prominent protein kinase of RLCK subfamily VII (RLCK-VII), interacted with SHOU4/4L and phosphorylated multiple serine residues on SHOU4L N-terminus upon pattern flg22 treatment. Neither phospho-dead nor phospho-mimic SHOU4L variants complemented pathogen resistance and plant development defect of the loss-of-function mutant, suggesting that reversible phosphorylation of SHOU4L is critical to plant immunity and plant development. Co-immunoprecipitation data revealed that flg22 induced SHOU4L dissociation from cellulose synthase 1 (CESA1) and that a phospho-mimic SHOU4L variant inhibited the interaction between SHOU4L and CESA1, indicating the link between SHOU4L-mediated cellulose synthesis and plant immunity. This study thus identified SHOU4/4L as new components of PTI and preliminarily revealed the mechanism governing SHOU4L regulation by RLCKs.

The influence of bracket torque on external apical root resorption in bimaxillary protrusion patients: a retrospective study.

BACKGROUND: To evaluate the difference in root resorption between standard torque self-ligating brackets and high torque self-ligating brackets in bimaxillary protrusion patients after orthodontic treatment. METHODS: Pre-treatment and post-treatment Cone beam computed tomography (CBCT) of 32 patients (16 treated with the high torque DamonQ 0.022″ bracket and 16 with the 0.022″ standard torque self-ligating bracket) were selected. The first premolars were extracted from all patients before treatment. After mini-screw implants were inserted into the buccal region between the second premolar and first molar, 150 g of force was applied to retract the upper and lower anterior teeth to close the extraction space on each side. CBCT images of all patients were taken before and after treatment. Three-dimensional reconstruction of the maxillary central incisor, lateral incisor and canine was conducted with Mimics 20.0 software. The volumes of the roots were calculated using Gomagics Studio 12.0 software. The differences between the pre-treatment and post-treatment root volumes were statistically evaluated with a paired-samples t-test. RESULTS: There was no statistically significant difference in root resorption degree between the two kinds of torque brackets. The patient's degree of root resorption in the high torque self-ligating group was greater than that in the standard torque group. CONCLUSIONS: There was no significant difference in root external apical resorption between the high torque self-ligating brackets and the standard torque self-ligating brackets in bimaxillary protrusion patients.

Acid-Activated Melittin for Targeted and Safe Antitumor Therapy.

Melittin (MLT), as a natural active biomolecule, can penetrate the tumor cell membrane to play a role in cancer treatment and will attract more attention in future development of antitumor drugs. The main component of natural bee venom MLT was modified by introducing a pH-sensitive amide bond between the 2,3-dimethyl maleimide (DMMA) and the lysine (Lys) of MLT (MLT-DMMA). MLT and its corresponding modified peptide MLT-DMMA were used for antitumor and biocompatibility validation. The biomaterial characteristics were tested by MALDI-TOF MS, 1H NMR, IUPAC and HPLC, cell viability, hemolytic and animal experiment safety evaluation. Compared with the primary melittin, the modified peptide showed decreased surface charge and low cytotoxicity in physiological conditions. Moreover, cell assays confirmed the acid-activated conversion of amide bond resulting in adequate safety during delivery and timely antitumor activity in tumor lesions. Thus, MLT-DMMA provided a feasible platform to improve the targeted and safe antitumor applications.

Effects of hydroformylation treatment on the storage time and blood group antigen expressions of reagent red blood cells.

OBJECTIVE: To evaluate the effects of hydroformylation treatment on the storage time and blood group antigen expressions of reagent red blood cells (RBCs). MATERIAL AND METHODS: RBCs from healthy donors were treated by using various final concentrations of paraformaldehyde (0.01%, 0.02%, 0.05%, 0.1%, 0.2%, 0.5% and 1.0%) and glutaraldehyde (0.01%, 0.025%, 0.05%, 0.1%, 0.2%, 0.5% and 1.0%), and one aliquot was used as control (untreated with aldehydes). Supernatant free hemoglobin (FHb) levels in all groups stored at 4 °C were detected every week, and the optimal procedure was selected. Expression of blood group antigens on RBCs treated by the optimal procedure was determined, and the total scores of blood group antigens were calculated. RESULTS: 0.2%, 0.5% and 1.0% Glutaraldehyde groups were ruled out directly due to serious crosslinking and aggregation of RBCs. As the extension of time, FHb levels in other 11 groups gradually increased (p<0.01 or p<0.05). FHb level in 0.025% glutaraldehyde group was significantly lower than that in other groups after 13 weeks (p<0.01), and the antigen strength of Fy(b), Jk(b), and Le(b) decreased slightly compared with those before treatment and storage (p<0.05), and there was no significant change for antigen strength of A, B, D, C, E, c, e, M, N, S, s, k, P1, Fy(a), Jk(a), and Le(a) (p>0.05). CONCLUSION: 0.025% Glutaraldehyde treatment can provide optimal protection for the membrane of RBCs and keep hemolysis at a low level after 13 weeks storage, and the majority of blood group antigen systems are not significantly affected, and the slight decline of Fy(b), Jk(b), and Le(b) antigen strength was acceptable for classical serological tests.

Magnetic resonance imaging evaluation of masticatory muscle changes in patients with primary trigeminal neuralgia before microvascular decompression.

Primary trigeminal neuralgia (PTN) is characterized by chronic neuropathic pain. There are few studies exploring masticatory muscle changes in patients with PTN. This study evaluated the changes in the masticatory muscles using magnetic resonance imaging (MRI) and the predictive factors of masticatory muscle changes in patients with PTN. The radiologic outcomes of 52 patients with PTN and 58 healthy adults were evaluated. The temporalis, lateral pterygoid, medial pterygoid, and masseter muscles were assessed using MRI. Atrophy and edema of the masticatory muscles were noted. Multivariate analyses were conducted to identify factors associated with masticatory muscle atrophy. Among the PTN group, the right side (61.5%) and mandibular branch (53.9%) were the most affected. Muscle atrophy of the temporalis (P < .001), medial pterygoid (P = .016), lateral pterygoid (P = .031), and masseter (P = .001) were significantly higher in the PTN group than in the control group. Lateral pterygoid edema was significantly higher in the PTN group (P < .001). However, no significant difference was found in the temporalis and masseter edema between the two groups. Logistic regression analysis demonstrated that neurovascular conflict (NVC) significantly predicted mastication muscle atrophy (P = .037). Patients with PTN had higher rates of masticatory muscle atrophy and edema. The assessment of NVC may be a preoperative imaging biomarker to predict atrophy in PTN.

Herceptin-Conjugated DOX-Fe3O4/P(NIPAM-AA-MAPEG) Nanogel System for HER2-Targeted Breast Cancer Treatment and Magnetic Resonance Imaging.

It is essential to synthesize a "diagnosis and therapy" integration nanocarrier for magnetic resonance imaging-guided breast cancer-targeted chemotherapy. Here, we report Fe3O4/P(NIPAM-AA-MAPEG) nanogels (MNLs) based on in situ loading of doxorubicin (DOX) by miniemulsion polymerization. Especially, propyl acrylic acid (AA) moieties were introduced to absorb DOX by electrostatic interactions and conjugated with the antibody herceptin (HER) through the amino-carboxyl coupling reaction. The size and morphology of MNLs could be adjusted by varying the polymerization parameters, such as the monomer feeding ratio, ferrofluid content, and cross-linker content. The MNLs showed superior stability in a physiological environment, but their structures were destroyed in an acidic environment to accelerate DOX release. The dissociation of the HER-DOX-MNLs accelerated the delivery of DOX and enhanced the therapeutic effects. The studies exhibited that the HER-DOX-MNLs could inhibit the tumor growth. In addition, the MNLs with a high magnetic content had the potential advantages in magnetic resonance imaging (MRI) of breast cancer diagnosis. The dual-targeted pH-responsive nanogels were successfully designed as a multifunctional nanocarrier for realizing HER2-positive breast cancer chemotherapy and diagnostics.

Highly time-resolved measurements of elements in PM2.5 in Changzhou, China: Temporal variation, source identification and health risks.

The temporal variation, sources, and health risks of elemental composition in fine particles (PM2.5) were explored using online measurements of 19 elements with a time resolution of 1 h at an urban location in Changzhou, China, from December 10, 2020 to March 31, 2021. The mass concentration of PM2.5 was 50.1 ±â€¯32.6 µg m-3, with a range of 3-218 µg m-3. The total concentration of 19 elements (2568 ±â€¯1839 ng m-3) accounted for 5.1 % of PM2.5 mass concentration. S, Cl, Si, and Fe were the dominant elementary species, accounting for 90 % of total element mass concentrations during the whole campaign. Positive matrix factorization (PMF) model was applied to identify the major emission sources of elements in PM2.5. Seven factors, named secondary sulfate mixed with coal combustion, Cl-rich, traffic, iron and steel industry, soil dust, fireworks, and shipping, were identified. The major sources for elements were iron and steel industry, followed by soil dust and secondary sulfate mixed with coal combustion, explaining 32.0 %, 23.5 % and 16.7 % of the total source contribution, respectively. The total hazard index (HI) of elements was 3.01 for children and 1.18 for adults, much greater than the admissible level (HI = 1). The total carcinogenic risk (CR) in Changzhou was estimated to be 5.87 × 10-5, which was above the acceptable CR level (1 × 10-6). Among the calculated metal elements, Cr, Co and As have higher carcinogenic risk, and Co was found to trigger the highest noncarcinogenic risk to Children. Our results indicate that industrial emission is the dominant CR contributor, emphasizing the necessity for stringent regulation of industry sources. Overall, our study provides useful information for policymakers to reduce emissions and health risks from elements in the Yangtze River Delta region.

The in vivo dissolution of tricalcium silicate bone cement.

This study aimed to investigate the in vivo dissolution of tricalcium silicate (Ca3 SiO5 , C3 S) bone cement in the rabbit femoral defect. Results indicated that C3 S paste directly integrated with the bone tissue without the protection of the bone-like apatite. Calcium silicate hydrate gel (C-S-H gel) and Ca(OH)2 were the main components of C3 S paste. The dissolution model of C3 S paste was a mass loss rather than a decrease in volume. The initial dissolution of C3 S paste (0 ~ 6 weeks) was greatly attributed to the release of Ca(OH)2 , and the later dissolution (>6 weeks) was attributed to the decalcification of C-S-H gel. Although the mass of C3 S paste could decrease by more than 19 wt % after 6 weeks of implantation, the created pores (<1 µm) were not large enough for the bone tissue to migrate into C3 S paste. The loss of Ca ions also resulted in the transformation of SiO4 tetrahedrons from Q1 and Q2 to Q0 , Q3 , and Q4 in C-S-H gel. Because only isolated SiO4 tetrahedrons (Q0 ) and Ca ions could be absorbed by the bone tissue, C3 S paste gradually transformed into a silica-rich gel. The fundamental reason for no decrease in volume of C3 S paste was that the SiO4 tetrahedron network still maintained the frame structure of C3 S paste during the implantation.

Using Magnetic and Photic Stimuli-Responsive Liposomes to Serve Up Chemotherapy Drugs to Cancer Cells.

Liposome is a traditional drug-delivery system and most novel studies have focused on its drug release function. In this paper, a new drug-delivery system based on liposomes was prepared, which contains hydrophobic FeAg alloy nanoparticles (FeAgNPs) in their lipid bilayer and berberine as test drug in their middle water phase. The size of AgFe-Ls was about 200 nm, the encapsulation efficiency of drugs was 35% and the lower critical solution temperature (LCST) of AgFe-Ls was about 41.96 °C. FeAgNPs in the AgFe-Ls had a 1:1 iron-to-silver atomic ratio with both optical and superparamagnetic properties. The photothermal effect and magnetocaloric effect of FeAgNPs could serve up both photo-stimulated and magnetic- stimulated drug release to liposomes. Release experiments results showed that AgFe-Ls could easily release berberine when stimulated by UV light (45% drug release at 20 min) or alternating current electromagnetic field (AMF) (80% drug release at 4 h). AgFe-Ls with both photo-controlled and magnetic-controlled drug release functions are promising to serve up chemotherapy drugs to cancer cells.

Cell-penetrating peptide enhanced insulin buccal absorption.

Non-injectable delivery of peptides and proteins is not feasible due to the limitations of large molecular mass, high hydrophilic properties, and gastrointestinal degradation. Therefore, proposing a new method to solve this problem is a burning issue. The objective of this study was to propose a novel protein delivery strategy to overcome the poor efficacy and irritation of buccal insulin delivery. In this study, we applied a conjugate of cell-penetrating peptides (LMWP) and insulin (INS-PEG-LMWP) for buccal delivery. INS-PEG-LMWP was prepared using insulin solution and mixture as references. The transport behaviour, in vivo bioactivity, hypoglycaemic effect, and safety of INS-PEG-LMWP were systematically characterised. An in vitro study demonstrated that the uptake and transportation of INS-PEG-LMWP across buccal mucosal multilayers significantly increased. By comparing the effects of different endocytic inhibitors on INS-PEG-LMWP uptake, the conjugate might be delivered via an energy independent, electrostatically adsorbed pathway. INS-PEG-LMWP's relative pharmacological bioavailability was high and its relative bioavailability was up to 26.86%, demonstrating no visible mucosal irritation. Cell-penetrating peptides are likely to become a reliable and safe tool for overcoming insulin's low permeability through the epithelial multilayers, the major barrier to buccal delivery.

Covalent immobilization of biomolecules on stent materials through mussel adhesive protein coating to form biofunctional films.

It is widely accepted that surface biofunctional modification may be an effective approach to improve biocompatibility and confer new bioactive properties on biomaterials. In this work, mussel adhesive protein (MAP) was applied as a coating on 316 L stainless steel substrates (316 L SS) and stents, and then either immobilized VEGF or CD34 antibody were added to create biofunctional films. The properties of the MAP coating were characterized by scanning electron microscope (SEM), atomic force microscope (AFM) and a water contact angle test. Universal tensile testing showed that the MAP coating has adequate adhesion strength on a 316 L stainless steel material surface. Subsequent cytotoxicity and hemolysis rate tests showed that the MAP coatings have good biocompatibility. Moreover, using N-(3-Dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride and N-hydroxysulfosussinimide (EDC/NHS) chemistry, VEGF and CD34 antibody were immobilized on the MAP coatings. The amount and immobilized yield of VEGF on the MAP coatings were analyzed by enzyme-linked immuno-assays (ELISA). Finally, an endothelial cells culture showed that the VEGF biofunctional film can promote the viability and proliferation of endothelial cells. An in vitro CD34+ cells capturing test also verified the bioactive properties of the CD34 antibody coated stents. These results showed that the MAP coatings allowed effective biomolecule immobilization, providing a promising platform for vascular device modification.

Co-hydrothermal carbonization of lignocellulosic biomass and waste polyvinyl chloride for high-quality solid fuel production: Hydrochar properties and its combustion and pyrolysis behaviors.

The rigid polyvinyl chloride (PVC) and pinewood sawdust (PS) were selected for co-hydrothermal carbonization (Co-HTC) process. The effects of hydrothermal reaction temperatures and the mixing ratios of raw materials were fully investigated. The results showed that hydrothermal reaction temperature increased could significantly promote the dechlorination efficiency at the mixing ratio of 1:1, which was 92.98% at 280 °C. The experimental HHV were higher than theoretical value and increased by 4.04%, 8.21% and 2.81% at the mixing ratios of 3:1, 1:1 and 1:3. The combustion behavior and the thermodynamic parameters of hydrochar were determined, and the activation energy tended to decrease. The Py-GC/MS analysis showed the changes of the distribution for the pyrolysis product. Aliphatic and aliphatic cyclic hydrocarbons were the main products of hydrochar pyrolysis, and the yield could be promoted by Co-HTC process. According to the FTIR spectrum, elimination and substitution were the primary mechanisms of dechlorination.

Biocompatible co-loading vehicles for delivering both nanoplatin cores and siRNA to treat hepatocellular carcinoma.

Bmi-1 is a gene related to malignant transformation in hepatocellular carcinoma (HCC). The liver cancer cells developed the ability to tolerate CDDP treatment with the elevation of Bmi-1. Bmi-1 is also an oncogene promoting malignance of tumor and an anti-cancer target in many studies. Herein, a biocompatible nanocarrier was designed in the study to deliver a chemotherapeutical agent CDDP and Bmi-1 siRNA to kill cancer cells and silence drug resistance related gene simultaneously. Calciumphosphate (CaP) was applied to coat both nanoplatin cores and siRNA as a shell for the purpose of delivering cargos to the cytosol of the tumor cells. Nanoplatin and siRNA co-loaded CaP nanoparticles (NPSC) enhanced cell uptake of CDDP and showed elevated drug accumulation in tumor. NPSC achieved considerable anti-cancer efficacy and counter-regulated drug tolerance, therefore, warranted a further investigation as a novel therapeutic nanosystem to improve cancer therapy.

Co-delivery of Bmi1 small interfering RNA with ursolic acid by folate receptor-targeted cationic liposomes enhances anti-tumor activity of ursolic acid in vitro and in vivo.

Overexpression of Bmi1 gene is an important feature of cancer stem cell in various human tumors. Therefore, Bmi1 gene can be a potential target for small interfering RNA (siRNA) mediated cancer therapy. Ursolic acid (UA) as a natural product plays a pivotal role in anti-tumor field, although its performance is limited by low bioavailability and poor hydrophilicity. A folate receptor-targeted cationic liposome system was designed for the purpose of investigating the relationship between Bmil siRNA and UA. The folate receptor-targeted cationic liposomes co-delivering UA and Bmi1 siRNA (FA-UA/siRNA-L) were fabricated by electrostatic interaction between folate UA liposome (FA-UA-L) and Bmi1 siRNA. Tumor growth is inhibited by FA-UA/siRNA-L in vitro and in vivo and this inhibition is contributed by a synergistic anti-tumor effect of UA and Bmi1 siRNA. The western blot measurement of apoptosis-protein and cancer stem cell (CSC) marked-protein demonstrated that UA led to activation-induced tumor cell death and Bmi1 siRNA resulted in inhibition of cancer stem cells. Overall, these results indicate that Bmi1 as a regulating gene for cancer stem cell is an effective target for cancer treatment using siRNA and co-delivery of UA and Bmi1 siRNA using folate-targeted liposomes is a promising strategy for improved anti-tumor effect.

Co-delivery of doxorubicin and imatinib by pH sensitive cleavable PEGylated nanoliposomes with folate-mediated targeting to overcome multidrug resistance.

Multidrug resistance to chemotherapeutic drugs is a major obstacle to breast cancer treatment. In this study, doxorubicin (DOX) and imatinib (IM) were co-loaded into folate receptor targeted (FR-targeted) pH-sensitive liposomes (denoted as FPL-DOX/IM) to fulfill intracellular acid-sensitive release and reverse drug resistance. FPL-DOX/IM could maintain stability in blood circulation with approximate diameters of 100 nm and rapidly release encapsulated drugs in tumor acidic microenvironment. Moreover, the IM in combination therapy could overcome chemoresistance associated with DOX effectively by inhibiting ABC transporter function and improving chemotherapy sensitivity. The designed liposomes co-loaded with DOX and IM significantly enhanced anti-tumor effects both in vitro and in vivo. These findings suggest that FPL-DOX/IM provides a novel strategy to improve chemotherapeutic efficacy against MDR tumors.

Enhancing anti-tumor efficiency in hepatocellular carcinoma through the autophagy inhibition by miR-375/sorafenib in lipid-coated calcium carbonate nanoparticles.

Sorafenib is a first-line drug for hepatocellular carcinoma (HCC). Autophagy has been shown to facilitate sorafenib resistance. miR-375 has been shown to be an inhibitor of autophagy. In this study, miR-375 and sorafenib were co-loaded into calcium carbonate nanoparticles with lipid coating (miR-375/Sf-LCC NPs). The nanoparticles had high loading efficiency and were ∼50 nm in diameter. Besides, the NPs could increase the stability and residence time of both drugs. Moreover, we demonstrated that autophagy was activated in HCC cells by sorafenib but not by miR-375/Sf-LCC NPs. In vitro, miR-375/Sf-LCC NPs exhibited pH-dependent drug release and potent cytotoxicity. In vivo, miR-375/Sf-LCC NPs increased miR-375 and sorafenib uptake in tumor (2 folds compared with Lipofectamine 2000-miR-375 and 2-5 folds compared with free sorafenib). Furthermore, miR-375/Sf-LCC NPs showed greatly enhanced therapeutic efficacy in an HCC xenograft model. These findings suggest that miR-375/Sf-LCC NPs may be a promising agent for the HCC therapy. STATEMENT OF SIGNIFICANCE: Hepatocellular carcinoma (HCC) is the most common primary liver tumor and the third leading cause of cancer mortality globally. In this manuscript, miR-375 and sorafenib were co-loaded into calcium carbonate nanoparticles with lipid coating (miR-375/Sf-LCC NPs) to treat HCC. We demonstrated that miR-375/Sf-LCC NPs can deliver sorafenib and miR-375 into HCC cells and tumor tissues, increase drug retention time in tumor, significantly inhibit autophagy and produce enhanced anti-tumor effect.

Cisplatin and curcumin co-loaded nano-liposomes for the treatment of hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) continues to be a leading cause of cancer related death in the world. Conventional chemotherapeutic agents such as cisplatin (CDDP) have an unsatisfactory efficacy on HCC due to the poor response, severe toxicity and drug resistance. Curcumin (CUR) could improve the chemosensitivity of HCC to chemotherapy drugs by regulating a variety of signaling pathways. Herein, we describe a combination strategy using co-loaded liposomes to effectively deliver and release CDDP and curcumin (CUR) to HCC for overcoming the unsatisfactory clinical outcome of CDDP monotherapy. In the study, CDDP and CUR co-loaded liposomes (CDDP/CUR-Lip) were prepared by a reverse microemulsion and film dispersion method and their average particle size 294.6 ±â€¯14.8 nm with uniform size distribution. In vitro study showed that the nano sized CDDP/CUR-Lip could synchronously release both CDDP and CUR to achieve the synergistic effect against HCC cells based on the optimal ratio (1:8) of both drugs. Compared with free drug or encapsulated mono-drug therapy, CDDP/CUR-Lip demonstrated the higher anti-tumor activity in vitro against HepG2 cells with the IC50 of 0.62 µM. In addition, CDDP/CUR-Lip also increased intracellular ROS level during the HCC cells treatment. Furthermore, compared with single drug formulation, CDDP/CUR-Lip showed the elongated retention time (t1/2 = 2.38 h) and improved antitumor effect in both mouse hepatoma H22 and human HCC HepG2 xenograft models with reduced side effects. In conclusion, CDDP/CUR-Lip provide an attractive and potential strategy to attain synergistic effect of CDDP and CUR for the treatment of HCC.

Immobilization of heparin/poly-l-lysine microspheres on medical grade high nitrogen nickel-free austenitic stainless steel surface to improve the biocompatibility and suppress thrombosis.

Thrombosis formation, restenosis, and delayed endothelium regeneration continue to be a challenge for coronary artery stent therapy. To improve the hemocompatibility of cardiovascular implants and to selectively direct vascular cell behavior, a novel heparin/poly-l-lysine microsphere was developed and immobilized on a dopamine-coated surface. We chose medical grade high nitrogen nickel-free austenitic stainless steel as the stent material since it has better biocompatibility. The stability and structural characteristics of the microspheres changed with the heparin: poly-l-lysine concentration ratio. Antithrombin III binding was significantly enhanced. Furthermore, for plasma coagulation tests, the activated partial thromboplastin time and thrombin time were prolonged and depended on the heparinfunction. The modified exhibited excellent stability and anticoagulant activity, and efficiently accelerated endothelialization and anticoagulation. This work has potential application for the design of coronary artery stent surfaces tailored for vascular cell behavior.

Metabolic engineering of a laboratory-evolved Thermobifida fusca muC strain for malic acid production on cellulose and minimal treated lignocellulosic biomass.

Malic acid is mainly used as an acidulant and taste enhancer in the beverage and food industry. Previously, a mutant strain Thermobifida fusca muC, obtained by adaptive evolution was found to accumulate malic acid on cellulose with low yield. In this study, the malic acid synthesis pathway in T. fusca muC was confirmed to be from phosphoenolpyruvate to oxaloacetate, followed by reduction of oxaloacetate to malate. To increase the yield of malic acid by the muC strain significantly, the carbon flux from pyruvate was redirected to oxaloacetate by expressing an exogenous pyruvate carboxylase (PCx) gene from Corynebacterium glutamicum ATCC 13032 in the chromosome of T. fusca muC-16. The yield of malic acid in the engineered strain muC-16 was increased by 47.9% compared to the parent strain muC. The muC-16 strain was then grown on ∼100 g/L cellulose and the highest titer of malic acid was 62.76 g/L by batch fermentation. T. fusca muC-16 strain converted milled corn stover to malic acid with the highest titer of 21.47 g/L with minimal treatment.

In vivo behaviors of Ca(OH)2 activated nano SiO2 (nCa/nSi=3) cement in rabbit model.

In vivo behaviors of Ca(OH)2 activated nano SiO2 (nCa/nSi=3, TCS) cement were investigated in the rabbit femoral defects using the poly(methyl methacrylate) (PMMA) as control. The deposited apatite and CaCO3 layers round TCS paste surfaces were completely used to construct the new bone tissue. TCS paste could stimulate the formation of new bone tissue in marrow tissue. The osteostimulation was mainly attributed to the proliferation and differentiation effects of Ca and Si ions released from TCS paste on the osteoprogenitor cells. However, Calcium-Silicate-Hydrate (C-S-H) gel in TCS paste was harder to degradate than Ca(OH)2. TCS paste kept the original shape during implantation, and could not provide the pores or spaces for further formation of bone tissue. Osteolytic defects induced by wear particles from TCS paste surface could not be completely avoided, because of the interfacial strain and the extensive micromotion between TCS paste surface and new bone tissue. Overall, our results indicated that Ca(OH)2 activated nano SiO2 cement was bioactivity and osteostimulation. The further improvements of Ca(OH)2 activated nano SiO2 cement should be done by achieving a balance between biological properties and mechanical performances.