A Scalable Microfluidic Platform for Nanoparticle Formulation: For Exploratory- and Industrial-Level Scales.

Nanoparticle synthesis on microfluidic platforms provides excellent reproducibility and control over bulk synthesis. While there have been plenty of platforms for producing nanoparticles (NPs) with controlled physicochemical properties, such platforms often operate in a narrow range of predefined flow rates. The flow rate limitation restricts either up-scalability for industrial production or down-scalability for exploratory research use. Here, we present a universal flow rate platform that operates over a wide range of flow rates (0.1-75 mL/min) for small-scale exploratory research and industrial-level synthesis of NPs without compromising the mixing capabilities. The wide range of flow rate is obtained by using a coaxial flow with a triangular microstructure to create a vortex regardless of the flow regime (Reynolds number). The chip synthesizes several types of NPs for gene and protein delivery, including polyplex, lipid NPs, and solid polymer NPs via self-assembly and precipitation, and successfully expresses GFP plasmid DNA in human T cells.

Silicone elastomer gel impregnated with 20(S)-protopanaxadiol-loaded nanostructured lipid carriers for ordered diabetic ulcer recovery.

Inefficient diabetic ulcer healing and scar formation remain a challenge worldwide, owing to a series of disordered and dynamic biological events that occur during the process of healing. A functional wound dressing that is capable of promoting ordered diabetic wound recovery is eagerly anticipated. In this study, we designed a silicone elastomer with embedded 20(S)-protopanaxadiol-loaded nanostructured lipid carriers (PPD-NS) to achieve ordered recovery in scarless diabetic ulcer healing. The nanostructured lipid carriers were prepared through an emulsion evaporation-solidification method and then incorporated into a network of silicone elastomer to form a unique nanostructured lipid carrier-enriched gel formulation. Interestingly, the PPD-NS showed excellent in vitro anti-inflammatory and proangiogenic activity. Moreover, in diabetic mice with full-thickness skin excision wound, treatment with PPD-NS significantly promoted in vivo scarless wound healing through suppressing inflammatory infiltration in the inflammatory phase, promoting angiogenesis during the proliferation phase, and regulating collagen deposition in the remodeling phase. Hence, this study demonstrates that the developed PPD-NS could facilitate ordered diabetic wound recovery via multifunctional improvement during different wound-healing phases. This novel approach could be promising for scarless diabetic wound healing.

Transplant of insulin-like growth factor-1 expressing bone marrow stem cells improves functional regeneration of injured rat uterus by NF-κB pathway.

To investigate the potential beneficial effect of insulin-like growth factor-1 (IGF-1) in BMSC transplantation therapy of uterus injury and the underlying molecular mechanisms, rat BMSCs were isolated and cultured. The relative expressions of IGF-1 and IL-10 were determined by RT-PCR and immunoblotting. The secretory IL-10 and released E2 were measured using ELISA kits. The relative vWF and α-SMA expressions were determined by immunohistochemistry. The direct binding of NF-κB subunit p50 with IL-10 promoter was analysed by chromatin immunoprecipitation assay. The regulation of IL-10 expression by p50 was interrogated by luciferase reporter assay. Our data demonstrated that IGF-1 expression in BMSCs induced IL-10 expression and secretion, which was further enhanced by E2-PLGA. IGF-1 overexpression improved BMSCs transplantation therapy in rat uterus injury. We further demonstrated that both inhibition and knockdown of p50 abolished IGF-1-induced expression and secretion of IL-10 in BMSCs, which consequently compromised the IGF-1 conferred therapeutic benefits against uterus injury. Furthermore, we elucidated that p50 regulated IL-10 expression via direct association with its promoter. Our data suggested that transplantation of IGF-1 overexpressing BMSCs improved functional regeneration of injured uterus by inducing IL-10 expression and secretion via activation of NF-κB signalling.

Patients with periodontitis might increase the risk of urologic cancers: a bidirectional two-sample Mendelian randomization study.

BACKGROUND: Numerous observational epidemiological studies have reported a bidirectional relationship between periodontitis and urological cancers. However, the causal link between these two phenotypes remains uncertain. This study aimed to examine the bidirectional causal association between periodontitis and four types of urological tumors, specifically kidney cancer (KC), prostate cancer (PC), bladder cancer (BC), and testis cancer (TC). METHODS: Based on large-scale genome-wide association study (GWAS) data, we utilized the two-sample Mendelian randomization (MR) approach to evaluate causal relationships between periodontitis and urological cancers. Several MR methods covering various consistency assumptions were applied in this study, including contamination mixture and Robust Adjusted Profile Score to obtain robust results. Summary-level data of individuals with European ancestry were extracted from the UK Biobank, the Kaiser GERA cohorts, and the FinnGen consortium. RESULTS: Our findings revealed significant positive genetic correlations between periodontitis and kidney cancer (OR 1.287; 95% CI 1.04, 1.594; P = 0.020). We did not find a significant association of periodontitis on prostate cancer, bladder cancer, and testis cancer. In reverse MR, no significant results were observed supporting the effect of urologic cancers on periodontitis (all P > 0.05). CONCLUSION: Our study provides the evidence of a potential causal relationship between periodontitis and kidney cancer. However, large-scale studies are warranted to confirm and elucidate the underlying mechanisms of this association.

Adjuvant activities of immunostimulating natural products: Astragalus membranaceus (Fisch.) Bge. and Coriolus versicolor in BNT162b2 vaccination against COVID-19 infection.

The global pandemic of COVID-19, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been developing all over the world for more than 3 years. In late 2020, several variants of concern of SARS-CoV-2 virus emerged, with increased viral fitness and transmissibility by mutations of the spike proteins of the viral particle, denting hopes of the use of early-generation vaccines for a widespread protective immunity against viral infection. The use of adjuvants may enhance the immune responses of the conventional application of the COVID-19 vaccine. We have shown that the water extract of 2 ß-glucan-enriched immunostimulating natural products, Astragalus membranaceus (Fisch.) Bge. (AM) and Coriolus versicolor (CV), could induce innate immunity-related cytokines from human monocytes (CCL5, interleukin [IL]-6, IL-10, and tumor necrosis factor α) and monocyte-derived dendritic cells (IL-1ß, IL-10, IL-12, and tumor necrosis factor α). Using BALB/c mice, orally administrated AM and CV (1,384 and 742 mg/kg/d) for 4 d after vaccination, respectively, could enhance (1) the immunoglobulin G binding activities of BNT162b2 vaccination against ancestral and Delta SARS-CoV-2 spike proteins by 5.8- and 4.3-fold, respectively; (2) the immunoglobulin G3 subclass production of BNT162b2 vaccination against ancestral and variant SARS-CoV-2 spike proteins; and (3) the in vitro antibody-neutralizing activities of BNT162b2 vaccinated mice. In conclusion, combining AM and CV was effective in acting as an oral adjuvant with the messenger RNA vaccine BNT162b2 to improve the antigen binding activities against SARS-CoV-2 ancestral and variant SARS-CoV-2 spike proteins, probably via trained immunity of macrophages and dendritic cells.

Transcriptomic Heterogeneity of Human Mesenchymal Stem Cells Derived from Bone Marrow, Dental Pulp, Adipose Tissue, and Umbilical Cord.

Compared with mesenchymal stem cells (MSCs) obtained from other tissue sources, those derived from umbilical cord (UC) tissue exhibit numerous advantages and vast potential for therapeutic applications. However, MSCs from different tissue sources are heterogeneous, and therefore, the therapeutic efficacy of UC-derived MSCs as a replacement for other tissue-derived MSCs needs to be studied. To better understand the distinctions between UC-derived MSCs and MSCs derived from other tissues, we conducted a transcriptome analysis of MSCs obtained from UC and three other tissues. Correlation analysis revealed the strongest correlation between UC-MSCs (UC-MSCs) and bone marrow-MSCs (BM-MSCs). Compared with UC-MSCs, the lower differentially expressed genes of BM-MSCs, dental pulp-MSCs (DP-MSCs), and adipose tissue-MSCs (AP-MSCs) were predominantly enriched in actin-related terms, while higher differentially expressed genes were predominantly enriched in immunological processes. We also analyzed the distribution of 34 frequently or highly expressed cell characterization molecules in BM-MSCs, DP-MSCs, AP-MSCs, and UC-MSCs. CD200 (FPKM >10) was only detected in UC-MSCs, while CD106 was detected in AD-MSCs and DP-MSCs (FPKM >10). The reliability of transcriptomic data analysis was verified by quantitative real-time PCR. Finally, we recommend the use of CD200, CD106, and other similar markers with unstable expression as benchmark molecules to monitor the proliferation and differentiation potential of MSCs. This study provides comprehensive insights into the heterogeneity between UC-MSCs and MSCs derived from other tissues, which can guide the therapeutic application of UC-MSCs.

Titanium-coated PEEK Versus Uncoated PEEK Cages in Lumbar Interbody Fusion: A Systematic Review and Meta-analysis of Randomized Controlled Trial.

STUDY DESIGN: Systematic review and meta-analysis. OBJECTIVE: This study was performed to compare the fusion and subsidence rate of titanium-coated polyetheretherketone (Ti-PEEK) versus polyetheretherketone (PEEK) cages after lumbar fusion and to investigate the clinical effect on patient-reported outcomes (PROMs). SUMMARY OF BACKGROUND DATA: Ti-PEEK cages have been developed to combine the advantages of both titanium alloy and PEEK, but whether they are superior to uncoated PEEK cages in bone fusion is still inconclusive. METHODS: PubMed, EMBASE, ISI Web of Science, CENTRAL, and CNKI were searched to identify randomized controlled trials that compared the efficacy of Ti-PEEK and PEEK cages in lumbar fusion. Difference in fusion rate and subsidence rate was indicated by risk ratio and its associated 95% confidence interval (95% confidence interval). Mean difference was calculated for Oswestry Disability Index and visual analogue scale for low back pain. Subgroup analysis was performed by time course after the surgery. The Grading of Recommendations, Assessment, Development and Evaluation approach was used to evaluate the certainty of evidence. RESULTS: Four randomized controlled trials involving 325 patients (160 patients in Ti-PEEK group and 165 patients in PEEK group) that underwent lumbar fusion were included by our current study. Low to moderate evidence suggested that Ti-PEEK and PEEK cages exhibited equivalent fusion rate and subsidence rate at any follow-up time. Low to moderate evidence suggested that there was no difference in PROMs except for visual analogue scale measured at 6 months (mean difference: -0.57, 95% confidence interval -0.94, -0.21; P =0.002) but the difference was not clinically relevant according to the minimal clinically important difference. CONCLUSION: Low to moderate evidence showed that Ti-PEEK and PEEK had equivalent effect in bone fusion and cages subsidence at any follow-up time after lumbar fusion surgeries. Low to moderate evidence showed no clinically important difference in PROMs.

[Utility of nickel-titanium shape memory alloys of vertebral body reduction fixator with assisted distraction bar].

OBJECTIVE: To test the nickel-titanium (Ni-Ti) shape memory alloys of vertebral body reduction fixator with assisted distraction bar for the treatment of traumatic and osteoporotic vertebral body fracture. METHODS: A Ni-Ti shape memory alloys of vertebral body reduction fixator with assisted distraction bar was implanted into the compressed fracture specimens through vertebral pedicle with the radiographic monitoring to reduce the collapsed endplate as well as distract the compressed vertebral fracture. Radiographic film and computed tomographic reconstruction technique were employed to evaluate the effects of reduction and distraction. A biomechanic test machine was used to measure the fatigue and the stability of deformation of fixation segments. RESULTS: Relying on the effect of temperature shape memory, such an assembly could basically reduce the collapsed endplate as well as distract the compressed vertebral fracture. And when unsatisfied results of reduction and distraction occurred, its super flexibility could provide additional distraction strength. CONCLUSION: A Ni-Ti shape memory alloys of vertebral body reduction fixator with assisted distraction bar may provide effective endplate reduction, restore the vertebral height and the immediate biomechanic spinal stability. So the above assembly is indicated for the treatment of traumatic and osteoporotic vertebral body fracture.

Reversible thermal regulation for bifunctional dynamic control of gene expression in Escherichia coli.

Genetically programmed circuits allowing bifunctional dynamic regulation of enzyme expression have far-reaching significances for various bio-manufactural purposes. However, building a bio-switch with a post log-phase response and reversibility during scale-up bioprocesses is still a challenge in metabolic engineering due to the lack of robustness. Here, we report a robust thermosensitive bio-switch that enables stringent bidirectional control of gene expression over time and levels in living cells. Based on the bio-switch, we obtain tree ring-like colonies with spatially distributed patterns and transformer cells shifting among spherical-, rod- and fiber-shapes of the engineered Escherichia coli. Moreover, fed-batch fermentations of recombinant E. coli are conducted to obtain ordered assembly of tailor-made biopolymers polyhydroxyalkanoates including diblock- and random-copolymer, composed of 3-hydroxybutyrate and 4-hydroxybutyrate with controllable monomer molar fraction. This study demonstrates the possibility of well-organized, chemosynthesis-like block polymerization on a molecular scale by reprogrammed microbes, exemplifying the versatility of thermo-response control for various practical uses.

[Experimental study of laparoscopical lumbar interbody fusion with polyporus composite phosphate calcium and rhBMP-2 compounds in sheep].

OBJECTIVE: To study the efficacy of polyporus composite phosphate calcium and rhBMP-2 compounds with laparoscopical lumbar interbody fusion in sheep. METHODS: Fourteen uniform-weight adult sheep were randomly divided into three groups for LA-5 interbody fusion with titanium mesh. Autogenous bone and titanium mesh was applied with open anterior technique in group 1 (n=4). In group 2, 4 sheep were operated with laparoscope technique for LA-5 interbody fusion with composite phosphate calcium (CPC) and titanium mesh. In group 3, 6 sheep underwent laparoscopical L4-5 interbody fusion with titanium mesh as well as polyporus composite phosphate calcium and rhBMP-2 compounds. At Weeks 6 and 12 post-operation, the sheep were sacrificed for imaging, biomechanic and morphological examinations. RESULTS: Although there was no statistical difference between open and laparoscopical interbody fusion group when comparing the remaining disc and endplate decorticated, bone fusion occurred in 3 groups after 3 months. A much larger amount of bony callus was observed earlier in laparoscopical L4-5 interbody fusion group with titanium mesh as well as polyporus composite phosphate calcium and rhBMP-2 compounds than two other groups. CONCLUSION: Polyporus composite phosphate calcium and rhBMP-2 compounds are suitable prosthetic materials for clinical trials. When these materials are utilized with a laparoscopical technique, satisfactory interbody fusion may be achieved.

Kraft lignin grafted with isopentenol polyoxyethylene ether and the dispersion performance.

In order to develop a biomass-based superplasticizer, kraft lignin (KL) was grafted with isopentenol polyoxyethylene ether (TPEG) to prepare a novel macromonomer (KL-TPEG). It was shown that the retention ratio of the aliphatic CC bond increased from 81.07% to 90.20% with the increase of m(TPEG)/m(KL). When the grafting ratio was increased, the average number of TPEG grafted on one KL molecule was approximately 1.4, 3.1, 4.6, 6.2 and 7.6. The star-like structure was also confirmed by FT-IR, 1H NMR and GPC. KL-TPEG had favorable surface activity and dispersion stability on the cement particles. It was illustrated that the shear stress and shear viscosity of the cement slurries with KL-TPEG were significantly less than that of blank slurry. The dispersion-retention ability of KL-TPEG on the slurry was also gradually enhanced with the increase of the grafting ratio of TPEG. It was seldom reported on the biomass-based TPEG. Through modified with KL, the rheology behavior and the dispersion-retention ability of TPEG was greatly improved, and the cost of TPEG was also reduced, thus this study not only promoted the development of biomass-based macromonomer, but also helped for the high value utilization of lignin.

Optimization of an mRNA vaccine assisted with cyclodextrin-polyethyleneimine conjugates.

Messenger RNA (mRNA) vaccines have attracted great interest in recent years due to their high potency, safety profile, and potential of rapid development. Although a number of mRNA vaccines have entered clinical trials, there remain several challenges. Inefficient in vivo delivery of mRNA is the foremost one. Here we synthesized a conjugate composed of ß-cyclodextrin (ß-CD) and branched polyethyleneimine (molecular weight 2 kDa, bPEI2k) to deliver an mRNA vaccine. The CD-PEI (CP) conjugate helped the encapsulated mRNA molecules pass through the plasma membranes and escape from the endosomes, which consequently ensured high transfection efficiency. On this basis, we optimized several structural elements of mRNA molecules via synthesizing an advanced cap structure and incorporating untranslated regions (UTRs) and an extended poly(A) tail into the sequence. These modifications led to a higher expression level of encoded proteins, which was expected to induce potent immune responses with a relatively low dosage. We also investigated the relevance of the administration route to the immune responses induced by CP-assisted mRNA vaccines with in vivo evidence, providing a basis for the selection of optimum administration route in specific cases. This CP-based mRNA vaccine platform, with an optimized mRNA structure and administrated in a most appropriate route, holds a promise to be applied to specific antigens in the future. Graphical abstract.

Synthesis of carbon quantum dot-poly lactic-co-glycolic acid hybrid nanoparticles for chemo-photothermal therapy against bacterial biofilms.

Bacterial biofilm represents a protected mode of bacterial growth that significantly enhances the resistance to antibiotics. Poly lactic-co-glycolic acid (PLGA)-based nanoparticle delivery systems have been intensively investigated to combat the bacterial biofilms-associated infections. However, some drawbacks associated with current PLGA-based nanoformulations (e.g. the relatively low drug loading capability, premature burst release and/or incapability of on-demand release of cargos at the site of action) restrict the transition from the lab research to the clinical applications. One potent strategy to overcome the above-mentioned limitations is exploiting the unique properties of carbon quantum dots (CQDs) and combining CQDs with the conventional PLGA nanoparticles. In the present study, the CQDs were innovatively incorporated into PLGA nanoparticles by using a microfluidic method. The resulting CQD-PLGA hybrid nanoparticles presented good loading capability of azithromycin (a macrolide antibiotic, AZI) and tobramycin (an aminoglycoside antibiotic, TOB), and stimuli-responsive release of the cargos upon laser irradiation. Consequently, AZI-loaded CQD-PLGA hybrid nanoparticles showed chemo-photothermally synergistic anti-biofilm effects against P. aeruginosa biofilms. Additionally, the CQD-PLGA hybrid nanoparticles demonstrated good biocompatibility with the eukaryotic cells. Overall, the proof-of-concept of CQD-PLGA hybrid nanoparticles may open a new possibility in chemo-photothermal therapy against bacterial biofilms.

Sodium fluoride exposure triggered the formation of neutrophil extracellular traps.

In recent years, numerous studies paid more attention to the molecular mechanisms associated with fluoride toxicity. However, the detailed mechanisms of fluoride immunotoxicity in bovine neutrophils remain unclear. Neutrophil extracellular traps (NETs) is a novel immune mechanism of neutrophils. We hypothesized that sodium fluoride (NaF) can trigger NETs activation and release, and investigate the related molecular mechanisms during the process. We exposed peripheral blood neutrophils to 1 mM NaF for 120 min in bovine neutrophils. The results showed that NaF exposure triggered NET-like structures decorated with histones and granule proteins. Quantitative measurement of NETs content correlated positively with the concentration of NaF. Mechanistically, NaF exposure increased reactive oxygen species (ROS) levels and phosphorylation levels of ERK, p38, whereas inhibiting the activities of superoxide dismutase (SOD) and catalase (CAT) compared with control neutrophils. NETs formation is induced by NaF and this effect was inhibited by the inhibitors diphenyleneiodonium chloride (DPI), U0126 and SB202190. Our findings described the potential importance of NaF-triggered NETs related molecules, which might help to extend the current understanding of NaF immunotoxicity.

Zwitterionic Polymer-Gated Au@TiO2 Core-Shell Nanoparticles for Imaging-Guided Combined Cancer Therapy.

With advances in nanoparticle (NP) synthesis and engineering, nanoscale agents with both therapeutic and diagnostic functions have been increasingly exploited for cancer management. Herein, we synthesized a new type of zwitterionic polymer-gated Au@TiO2 core-shell nanoparticles, which showed that they could selectively target and efficiently eliminate cancer cells via photothermal therapy (PTT), photodynamic therapy (PDT), pH/NIR-induced drug release, and cationic therapy. Methods: In the present study, the multifunctional therapeutic agent [Mn@P(CitAPDMAEMA)@Au@TiO2@DOX] was prepared to treat cancer with imaging-guided combination method. Firstly, Au@TiO2 core-shell nanoparticles (NPs) were synthesized. Taking advantage of broad and strong photoabsorption and reactive oxygen species (ROS) generation, Au@TiO2 core-shell NPs facilitated the single light-induced PTT and PDT. Next, a chemotherapy drug doxorubicin (DOX) was loaded into Au@TiO2 core-shell NPs. Then, a biocompatible zwitterionic polymer P(CitAPDMAEMA) was grafted to improve the hemocompatibility of NPs and prolong the circulation time. The polymer also served as a capping or switching material for pH-triggered drug release. In addition, the cationic nature of P(CitAPDMAEMA) eased the binding to human cervical cancer (HeLa) cells and effectively inhibited their growth in acidic environments (termed cationic therapy). Moreover, with Mn2+ ions immanently chelated, Mn@P(CitAPDMAEMA)@Au@TiO2@DOX NPs were able to provide enhanced contrast under T1- or T2-weighted magnetic resonance imaging (MRI). Results: The in vitro and in vivo anticancer experiments demonstrated the tumor was effectively inhibited with minimal side effects by the multifunctional NPs. Conclusions: As far as we know, this is the first presentation of four therapeutic methods into one nanomaterial, which will open up a new dimension for the design of combined treatment.

Surface-assisted assembly of a histidine-rich lipidated peptide for simultaneous exfoliation of graphite and functionalization of graphene nanosheets.

Biological molecules have promising potential to exfoliate graphite and produce biocompatible graphene nano-materials for biomedical applications. Here, a systematic design of a histidine-rich lipidated peptide sequence is presented that simultaneously exfoliates graphite flakes and functionalizes the resulting graphene nanosheets (∼150 nm lateral size) with long-term dispersion stability in aqueous solution (>8 months). The details of peptide/peptide and peptide/graphite interactions are probed using various microscopy, spectroscopy and molecular dynamics simulation methods. The results show that histidine and stearic acid interact with the graphite surface through π-π stacking and hydrophobic forces, respectively. Surface-assisted assembly of peptide molecules is then initiated via hydrogen bonds between deprotonated histidine segments, and a textured peptide nano-structure is formed. The work of adhesion between the peptide and graphite is found to be high enough to promote exfoliation of graphite flakes through layer-by-layer peeling of graphene nanosheets. The positively charged arginine in the peptide is exposed outward, and is responsible for the stable dispersion. The peptide molecules are sufficiently small, presenting the possibility to insert into and increase the spacing between the graphitic layers for enhanced exfoliation. The peptide-functionalized graphene nanosheets not only show great biocompatibility with cells in vitro, but also enhance cancer drug uptake by the cells.

Anti-oral common pathogenic bacterial active acetylenic acids from Thesium chinense Turcz.

Discovery of agents for oral infectious diseases is always encouraged in natural products chemistry. A bioassay-guided isolation led to the isolation of two new acetylenic acids (1, 2) along with seven known ones (3-9) from the ethanol extract of Thesium chinense Turcz, a commonly used oral anti-bacterial and anti-inflammatory herb. Their structures were elucidated on the basis of spectroscopic and chemical evidence. Exocarpic acid (3) demonstrated the most promising activity against three tested oral pathogenic bacterial strains, Porphyromonas gingivalis, Fusobacterium nucleatum, and Streptococcus mutans, with minimum inhibitory concentration values of 0.86, 3.43, and 13.70 µg/mL, respectively. Compounds 1, 2, 4, 5 and 7 also showed potential activities against periodontal bacteria (P. gingivalis, F. nucleatum).

Vaccination of Sheep with a Methanogen Protein Provides Insight into Levels of Antibody in Saliva Needed to Target Ruminal Methanogens.

Methane is produced in the rumen of ruminant livestock by methanogens and is a major contributor to agricultural greenhouse gases. Vaccination against ruminal methanogens could reduce methane emissions by inducing antibodies in saliva which enter the rumen and impair ability of methanogens to produce methane. Presently, it is not known if vaccination can induce sufficient amounts of antibody in the saliva to target methanogen populations in the rumen and little is known about how long antibody in the rumen remains active. In the current study, sheep were vaccinated twice at a 3-week interval with a model methanogen antigen, recombinant glycosyl transferase protein (rGT2) formulated with one of four adjuvants: saponin, Montanide ISA61, a chitosan thermogel, or a lipid nanoparticle/cationic liposome adjuvant (n = 6/formulation). A control group of sheep (n = 6) was not vaccinated. The highest antigen-specific IgA and IgG responses in both saliva and serum were observed with Montanide ISA61, which promoted levels of salivary antibodies that were five-fold higher than the second most potent adjuvant, saponin. A rGT2-specific IgG standard was used to determine the level of rGT2-specific IgG in serum and saliva. Vaccination with GT2/Montanide ISA61 produced a peak antibody concentration of 7 × 1016 molecules of antigen-specific IgG per litre of saliva, and it was estimated that in the rumen there would be more than 104 molecules of antigen-specific IgG for each methanogen cell. Both IgG and IgA in saliva were shown to be relatively stable in the rumen. Salivary antibody exposed for 1-2 hours to an in vitro simulated rumen environment retained approximately 50% of antigen-binding activity. Collectively, the results from measuring antibody levels and stablility suggest a vaccination-based mitigation strategy for livestock generated methane is in theory feasible.

Mesenchymal stem cells and endothelial progenitor cells accelerate intra-aneurysmal tissue organization after treatment with SDF-1α-coated coils.

Recurrences of aneurysms remain the major drawback of detachable coils for the endovascular treatment of intracranial aneurysms. The aim of the present study is to develop new modified coils, coating the surface of platinum coils with silk fibroin (SF) consisting of stromal cell-derived factor-1α (SDF-1α), and evaluate its acceleration of organization of cavities and reduction of lumen size in a rat aneurysm model. The morphological characteristics of SDF-1α-coated coils were examined using scanning electron microscopy (SEM). Fifty experimental aneurysms were created and randomly divided into five groups: three groups were embolized with SDF-1α-coated coils (8 mm) and two of these groups need transplantation of mesenchymal stem cells (MSCs) or endothelial progenitor cells (EPCs); one group was embolized with bare coils (8 mm) and another group severed as control. After coil implantation for 14 or 28 days, the coils were harvested and histological analysis was performed. SEM photographs showed that SF/SDF-1α-coated coils have uniform size and a thin film compared with bare coils. In the group treated with SDF-1α-coated coils, tissue organization was accelerated and the proliferation of α-smooth muscle actin positive cells was promoted in the aneurysmal sac. Compared with unmodified coils, on day 28, tissue organization was significantly greater in the group treated with SDF-1α-coated coils and MSC or EPC transplantation. These results suggest that SDF-1α-coated coils with MSC or EPC transplantation may be beneficial in the aneurysm healing and endothelialization at the orifice of embolized aneurysm.

Vaccination of cattle with a methanogen protein produces specific antibodies in the saliva which are stable in the rumen.

Methane is produced in the rumen of cattle by a group of archaea (single-celled organisms forming a domain distinct from bacteria and eucarya) called methanogens. Vaccination against methanogens has the potential to reduce methane emissions by inducing antibodies in saliva which are transferred to the rumen and diminish the ability of methanogens to produce methane. Since it is likely that an effective vaccination strategy will need to produce high levels of methanogen-specific antibody in the saliva; the choice of adjuvant, route of vaccination and stability of saliva-derived antibody in the rumen all need to be considered. In this study, stability of IgA and IgG in rumen fluid was determined using an in vitro assay. IgA levels in cattle saliva were reduced by only 40% after 8h exposure to rumen contents while IgG levels were reduced by 80%. These results indicated that antibody is relatively stable in the bovine rumen. A trial was conducted in cattle to investigate induction of immune responses to a methanogen protein, recombinant glycosyl transferase protein (rGT2) from Methanobrevibacter ruminantium M1. Groups of cattle (n=6) were vaccinated subcutaneously with rGT2, formulated with Montanide ISA61 with or without the TLR4 agonist, monophosphoryl lipid A (MPL). A control group (n=6) was not vaccinated. Strong antigen-specific IgG and moderate IgA responses were measured in the serum and saliva of the vaccinated animals and antibody was also detected in the rumen.