Bacterial cysteate dissimilatory pathway involves a racemase and d-cysteate sulfo-lyase.

The sulfite-reducing bacterium Bilophila wadsworthia, a common human intestinal pathobiont, is unique in its ability to metabolize a wide variety of sulfonates to generate sulfite as a terminal electron acceptor (TEA). The resulting formation of H2S is implicated in inflammation and colon cancer. l-cysteate, an oxidation product of l-cysteine, is among the sulfonates metabolized by B. wadsworthia, although the enzymes involved remain unknown. Here we report a pathway for l-cysteate dissimilation in B. wadsworthia RZATAU, involving isomerization of l-cysteate to d-cysteate by a cysteate racemase (BwCuyB), followed by cleavage into pyruvate, ammonia and sulfite by a d-cysteate sulfo-lyase (BwCuyA). The strong selectivity of BwCuyA for d-cysteate over l-cysteate was rationalized by protein structural modeling. A homolog of BwCuyA in the marine bacterium Silicibacter pomeroyi (SpCuyA) was previously reported to be a l-cysteate sulfo-lyase, but our experiments confirm that SpCuyA too displays a strong selectivity for d-cysteate. Growth of B. wadsworthia with cysteate as the electron acceptor is accompanied by production of H2S and induction of BwCuyA. Close homologs of BwCuyA and BwCuyB are present in diverse bacteria, including many sulfate- and sulfite-reducing bacteria, suggesting their involvement in cysteate degradation in different biological environments.

Isethionate is an intermediate in the degradation of sulfoacetate by the human gut pathobiont Bilophila wadsworthia.

The obligately anaerobic sulfite-reducing bacterium Bilophila wadsworthia is a common human pathobiont inhabiting the distal intestinal tract. It has a unique ability to utilize a diverse range of food- and host-derived sulfonates to generate sulfite as a terminal electron acceptor (TEA) for anaerobic respiration, converting the sulfonate sulfur to H2S, implicated in inflammatory conditions and colon cancer. The biochemical pathways involved in the metabolism of the C2 sulfonates isethionate and taurine by B. wadsworthia were recently reported. However, its mechanism for metabolizing sulfoacetate, another prevalent C2 sulfonate, remained unknown. Here, we report bioinformatics investigations and in vitro biochemical assays that uncover the molecular basis for the utilization of sulfoacetate as a source of TEA (STEA) for B. wadsworthia, involving conversion to sulfoacetyl-CoA by an ADP-forming sulfoacetate-CoA ligase (SauCD), and stepwise reduction to isethionate by NAD(P)H-dependent enzymes sulfoacetaldehyde dehydrogenase (SauS) and sulfoacetaldehyde reductase (TauF). Isethionate is then cleaved by the O2-sensitive isethionate sulfolyase (IseG), releasing sulfite for dissimilatory reduction to H2S. Sulfoacetate in different environments originates from anthropogenic sources such as detergents, and natural sources such as bacterial metabolism of the highly abundant organosulfonates sulfoquinovose and taurine. Identification of enzymes for anaerobic degradation of this relatively inert and electron-deficient C2 sulfonate provides further insights into sulfur recycling in the anaerobic biosphere, including the human gut microbiome.

Anaerobic Hydroxyproline Degradation Involving C-N Cleavage by a Glycyl Radical Enzyme.

Hydroxyprolines are highly abundant in nature as they are components of many structural proteins and osmolytes. Anaerobic degradation of trans-4-hydroxy-l-proline (t4L-HP) was previously found to involve the glycyl radical enzyme (GRE) t4L-HP dehydratase (HypD). Here, we report a pathway for anaerobic hydroxyproline degradation that involves a new GRE, trans-4-hydroxy-d-proline (t4D-HP) C-N-lyase (HplG). In this pathway, cis-4-hydroxy-l-proline (c4L-HP) is first isomerized to t4D-HP, followed by radical-mediated ring opening by HplG to give 2-amino-4-ketopentanoate (AKP), the first example of a ring opening reaction catalyzed by a GRE 1,2-eliminase. Subsequent cleavage by AKP thiolase (OrtAB) yields acetyl-CoA and d-alanine. We report a crystal structure of HplG in complex with t4D-HP at a resolution of 2.7 Å, providing insights into its catalytic mechanism. Different from HypD commonly identified in proline-reducing Clostridia, HplG is present in other types of fermenting bacteria, including propionate-producing bacteria, underscoring the diversity of enzymatic radical chemistry in the anaerobic microbiome.

The Effect of Circumscribed Exposure to the Pan-Aurora Kinase Inhibitor VX-680 on Proliferating Euploid Cells.

Small molecule inhibitors of aurora kinases are currently being investigated in oncology clinical trials. The long-term effects of these inhibitors on proliferating euploid cells have not been adequately studied. We examined the effect of the reversible pan-aurora kinase inhibitor VX-680 on p53-competent human euploid cells. Circumscribed treatment with VX-680 blocked cytokinesis and arrested cells in G1 or a G1-like status. Approximately 70% of proliferatively arrested cells had 4N DNA content and abnormal nuclei. The remaining 30% of cells possessed 2N DNA content and normal nuclei. The proliferative arrest was not due to the activation of the tumor suppressor Rb and was instead associated with rapid induction of the p53-p21 pathway and p16. The induction was particularly evident in cells with nuclear abnormalities but was independent of activation of the DNA damage response. All of these effects were correlated with the potent inhibition of aurora kinase B. After release from VX-680, the cells with normal nuclei robustly resumed proliferation whereas the cells with abnormal nuclei underwent senescence. Irrespective of their nuclear morphology or DNA content, cells pre-treated with VX-680 failed to grow in soft agar or form tumors in mice. Our findings indicate that an intermittent treatment strategy might minimize the on-target side effects of Aurora Kinase B (AURKB) inhibitory therapies. The strategy allows a significant fraction of dividing normal cells to resume proliferation.

Comparative transcriptome and metabolomic profiling reveal the complex mechanisms underlying the developmental dynamics of tobacco leaves.

Although the leaf is the most important photosynthetic organ in most plants, many of the molecular mechanisms underlying leaf developmental dynamics remain to be explored. To better understand the transcriptional regulatory mechanisms involved in leaf development, we conducted comparative transcriptomic and metabolomic analysis of leaves from seven positions on tobacco (Nicotiana tabacum) plants. A total of 35,622 unique differentially expressed genes and 79 metabolites were identified. A time-series expression analysis detected two interesting transcriptional profiles, one comprising 10,197 genes that displayed continual up-regulation during leaf development and another comprising 4696 genes that displayed continual down-regulation. Combining these data with co-expression network results identified four important regulatory networks involved in photorespiration and the tricarboxylic acid cycle; these networks may regulate carbon/nitrogen balance during leaf development. We also found that the transcription factor NtGATA5 acts as a hub associated with C and N metabolism and chloroplast development during leaf development through regulation of phytohormones. Furthermore, we investigated the transcriptional dynamics of genes involved in the auxin, cytokinin, and jasmonic acid biosynthesis and signaling pathways during tobacco leaf development. Overall, our study greatly expands the understanding of the regulatory network controlling developmental dynamics in plant leaves.

Purification and characterization of a high salt-tolerant alginate lyase from Cobetia sp. WG-007.

An alginate lyase producing bacterial strain, Cobetia sp. WG-007, was isolated and identified from rotting seaweed. The alginate lyase, Aly-W02, was purified by procedures of ultrafiltration, Q-Sepharose Fast Flow, Phenyl Sepharose 6 Fast Flow, and Superdex-G100 with specific activity of 21,285.5 U/mg. Aly-W02 had an apparent molecular mass of 35 kDa. It exhibited maximum activity at 45 °C in 50 mM sodium phosphate buffer (pH 8.5). This alginate lyase was stable in the pH range of 6.0-8.5. Among the tested metal ions, the addition of K+ , Na+ , and Mg2+ ions can enhance the enzyme activities, while Ba2+ , Ni+ , Cu2+ , Mn2+ , Zn2+ , Ag+ , and ethylenediaminetetraacetic acid decreased the activities. It displayed high salt-tolerant ability; 0.8 M NaCl or 1.5 M KCl significantly enhanced the enzyme activity. Furthermore, Aly-W02 mainly released disaccharide, trisaccharide, and tetrasaccharid from alginate. It showed potential in producing low molecular weight alginate oligosaccharides.

Pyrotinib versus lapatinib therapy for HER2 positive metastatic breast cancer patients after first-line treatment failure: A meta-analysis and systematic review.

INTRODUCTION: It is critical to select subsequent treatments for patients after the failure of trastuzumab therapy. Following the failure of standard trastuzumab therapy guidelines in the Chinese Society of Clinical Oncology, pyrotinib and capecitabine is a grade I recommended regimen for treating patients with HER2-positive metastatic breast cancer. Concurrently, in treating patients with HER2-positive metastatic breast cancer, lapatinib and capecitabine are also recommended regimens for those who have previously received taxanes, anthracyclines, and trastuzumab therapy. However, there is currently no systematic review and meta-analysis comparing pyrotinib with lapatinib among HER2+ MBC patients. Therefore, this study aims to perform a systematic review and meta-analysis and assess whether pyrotinib is superior to lapatinib in efficacy and safety. METHODS: Relevant trials were searched in CNKI, Wanfang, VIP, PubMed, Embase, and Cochrane CENTRAL databases from inception until March 27th, 2022. The primary outcomes were PFS and OS, and the secondary outcomes were ORR and grade ≥3 AEs. RESULTS: Five relevant studies were included in this study, including 2 RCTs and 3 retrospective cohort studies. Pyrotinib combined with chemotherapy is superior to lapatinib combined with chemotherapy among HER2+ metastatic breast cancer patients, with a significant improvement in PFS (prior trastuzumab therapy) (HR: 0.47, 95% CI: 0.39-0.57, p<0.001, I2 = 0%, FEM), PFS (trastuzumab resistance) (HR: 0.52, 95% CI: 0.39-0.68, p<0.001, I2 = 40%, FEM) and ORR (RR: 1.45, 95% CI: 1.26-1.67, p<0.001, I2 = 8%, FEM), but has higher grade ≥3 diarrhea incidence (RR: 2.68, 95% CI: 1.85-3.90, p<0.001, I2 = 44%, FEM). CONCLUSIONS: The efficacy of pyrotinib combined with chemotherapy is superior to lapatinib combined with chemotherapy but has more safety risks.

The Aurora kinase B relocation blocker LXY18 triggers mitotic catastrophe selectively in malignant cells.

The mitotic regulator, Aurora kinase B (AURKB), is frequently overexpressed in malignancy and is a target for therapeutic intervention. The compound, LXY18, is a potent, orally available small molecule that inhibits the proper localization of AURKB during late mitosis, without affecting its kinase activity. In this study, we demonstrate that LXY18 elicits apoptosis in cancer cells derived from various indications, but not in non-transformed cell lines. The apoptosis is p53-independent, triggered by a prolonged mitotic arrest and occurs predominantly in mitosis. Some additional cells succumb post-mitotic slippage. We also demonstrate that cancer cell lines refractory to AURKB kinase inhibitors are sensitive to LXY18. The mitotic proteins MKLP2, NEK6, NEK7 and NEK9 are known regulators of AURKB localization during the onset of anaphase. LXY18 fails to inhibit the catalytic activity of these AURKB localization factors. Overall, our findings suggest a novel activity for LXY18 that produces a prolonged mitotic arrest and lethality in cancer cells, leaving non-transformed cells healthy. This new activity suggests that the compound may be a promising drug candidate for cancer treatment and that it can also be used as a tool compound to further dissect the regulatory network controlling AURKB localization.

To determine the bioactivity of IL-1ß monoclonal antibodies: Introduction of a reliable reporter gene assay.

IL-1ß is a essential molecule in inflammatory signalling pathways and plays an essential role in inflammatory diseases. Accordingly, the development of monoclonal antibodies (mAbs) that target IL-1ß has become the focus of developing new anti-inflammatory drugs. The successful clinical application of therapeutic antibodies is dependent on good quality control, which is based on accurate bioactivity determination. The aim of this work was to develop an elegant and accurate reporter gene assay to determine the bioactivity of anti-IL-1ß antibody drugs. The D10-G4-1 cell line with a naturally high expression of IL-1 receptor was selected as the effector cell, and the plasmid containing luciferase reporter gene with NF-κB as a regulatory element was transfected into D10-G4-1 cells. After a period of pressure screening, a monoclonal cell line with good reactivity and stable expression of reporter gene was finally screened out. Stimulation of this cell line via IL-1ß addition increased the expression of the luciferase gene by activating the NF-κB signalling pathway, with the addition of luciferase substrate, which can be quantified by relative luminescence units. When anti-IL-1ß antibodies are present in the system, the expression of luciferase gene is inhibited, which demonstrates the bioactivity of anti-IL-1ß antibodies. Detailed methodological optimization and comprehensive methodological validation were followed to establish a reporter gene assay for the bioactivity of anti-IL-1ß antibodies.

Lapatinib and lapatinib plus trastuzumab therapy versus trastuzumab therapy for HER2 positive breast cancer patients: an updated systematic review and meta-analysis.

INTRODUCTION: Trastuzumab, as the gold standard for HER2-positive BC treatment, was the first-line HER2 targeted drug. However, some studies reported patients benefited more from lapatinib and lapatinib plus trastuzumab therapy than standard trastuzumab therapy. This study presents an update of a systematic review and meta-analysis involving comparison of lapatinib and lapatinib plus trastuzumab therapy versus trastuzumab therapy. AIM: We determined whether trastuzumab plus lapatinib or lapatinib therapy is not inferior to trastuzumab therapy in HER2-positive breast cancer patients. METHODS: Relevant trials were searched in CNKI, Wanfang, VIP, Sinomed, PubMed, Embase, and Cochrane CENTRAL databases from inception until October 25, 2021. Primary outcomes were OS, DFS/EFS, and PFS while secondary outcomes were pCR (ypT0/is ypN0), pCR (ypT0/is ypN0/+), ORR, DCR, rate of BCS, RFS, cardiac toxicities, and other toxicities. RESULTS: Thirteen randomized controlled trials were included in this study. Trastuzumab combined with lapatinib therapy was found to be superior to standard trastuzumab therapy alone with regard to overall survival, disease-free survival/event-free survival, pathologic complete response (ypT0/is ypN0), pathologic complete response (ypT0/is ypN0/+), recurrence-free survival, higher incidences of diarrhea, and rash/skin toxicity. Lapatinib therapy was established to be inferior to trastuzumab therapy in overall survival, progression-free survival, disease-free survival/event-free survival, pathologic complete response (ypT0/is ypN0) and pathologic complete response (ypT0/is ypN0/+), diarrhea, and rash/skin toxicity and had a low incidence of left ventricular ejection fraction decline. CONCLUSIONS: The efficacy of trastuzumab combined with lapatinib therapy is superior to standard trastuzumab therapy alone; however, it has more non-cardiac grade III/IV toxicities. Moreover, the efficacy of lapatinib therapy is inferior to that of standard trastuzumab therapy alone.

The phytochemical, corynoline, diminishes Aurora kinase B activity to induce mitotic defect and polyploidy.

Plants are a rich source for bioactive compounds. However, plant extracts can harbor a mixture of bioactive molecules that promote divergent phenotypes and potentially have confounding effects in bioassays. Even with further purification and identification, target deconvolution can be challenging. Corynoline and acetylcorynoline, are phytochemicals that were previously isolated through a screen for compounds able to induce mitotic arrest and polyploidy in oncogene expressing retinal pigment epithelial (RPE) cells. Here, we shed light on the mechanism by which these phytochemicals can attack human cancer cells. Mitotic arrest was coincident to the induction of centrosome amplification and declustering, causing multi-polar spindle formation. Corynoline was demonstrated to have true centrosome declustering activity in a model where A549 cells were chemically induced to have more than a regular complement of centrosomes. Corynoline could inhibit the centrosome clustering required for pseudo-bipolar spindle formation in these cells. The activity of AURKB, but not AURKA or polo-like kinase 4, was diminished by corynoline. It only partially inhibited AURKB, so it may be a partial antagonist or corynoline may work upstream on an unknown regulator of AURKB activity or localization. Nonetheless, corynoline and acetylcorynoline inhibited the viability of a variety of human cancer derived cell lines. These phytochemicals could serve as prototypes for a next-generation analog with improved potency, selectivity or in vivo bioavailability. Such an analog could be useful as a non-toxic component of combination therapies where inhibiting the chromosomal passenger protein complex is desired.

Anthropometric parameters of obesity can be alternative biomarkers for the potential cardiac dysfunction in obese children.

Childhood obesity, as one of the potential risk factors of cardiovascular diseases, is closely associated with the incidence of cardiovascular disease at a younger age and has become a public health concern worldwide. However, its potential effects on the cardiovascular system have still remained elusive. In this study, we systematically evaluated the cardiovascular characteristics of 79 obese children and 161 normal weight children in Guangzhou (China) using the potential biomarkers for cardiovascular disease. Compared with normal weight children, obese children not only exhibited significantly higher levels of creatine kinase (CK), lactate dehydrogenase (LHD), soluble fms-like tyrosine kinase-1 (s-Flt-1), high-sensitivity C-reactive protein (hs-CRP), and uric acid (UA) (p = 0.0062, 0.0012, 0.0013, 0.0225, and <0.0001, respectively) but also significantly higher diastolic blood pressure (p = 0.0074) and the heart rate (p = 0.0049) were found in obese children. Of 79 obese children, cardiac functions of 40 cases were further assessed by color Doppler echocardiography. The results showed that there were significant differences between the obesity group and the healthy weight group in terms of interventricular septal wall thickness at end-diastolic (IVSd), the left ventricular posterior wall thickness at end-diastolic (LVPWD), and aortic annulus (AO) (p < 0.0001, 0.0003, and p < 0.0001, respectively). Besides, the left and/or right ventricular functions were declined in 52.4% of obese children. Correlation analysis revealed that the anthropometric parameters of obesity were not only significantly correlated with a blood lipid profile but also exhibited a more significant correlation with most of the parameters of cardiac dysfunction than a blood lipid profile. Therefore, our study indicated that obese children in Guangzhou suffered from functional damages related to cardiovascular events, which were characterized by cardiac dysfunction, and the anthropometric parameters of obesity could be economically alternative biomarkers for monitoring of cardiac dysfunction in obese children.

Ultra-high pressure balloon angioplasty for pulmonary artery stenosis in children with congenital heart defects: Short- to mid-term follow-up results from a retrospective cohort in a single tertiary center.

Objective: Balloon angioplasty (BA) has been the treatment of choice for pulmonary artery stenosis (PAS) in children. There remains, however, a significant proportion of resistant lesions. The ultra-high pressure (UHP) balloons might be effective in a subset of these lesions. In this study, we analyzed the safety and efficacy with short- to mid-term follow-up results of UHP BA for PAS in children with congenital heart defects (CHD) in our center. Methods: This is a retrospective cohort study in a single tertiary heart center. Children diagnosed with PAS associated with CHD were referred for UHP BA. All data with these children were collected for analysis with updated follow-up. Results: A total of 37 UHP BAs were performed consecutively in 28 children. The success rate was 78.4%. A significantly (P = 0.005) larger ratio of the balloon to the minimal luminal diameter at the stenotic waist (balloon/waist ratio) was present in the success group (median 3.00, 1.64-8.33) compared to that in the failure group (median 1.94, 1.41 ± 4.00). Stepwise logistic regression analysis further identified that the balloon/waist ratio and the presence of therapeutic tears were two independent predictors of procedural success. The receiver operating characteristic curve revealed a cut-off value of 2.57 for the balloon/waist ratio to best differentiate success from failure cases. Signs of therapeutic tears were present in eight cases, all of whom were in the success group. Perioperative acute adverse events were recorded in 16 patients, including 11 pulmonary artery injuries, three pulmonary hemorrhages, and two pulmonary artery aneurysms. During a median follow-up period of 10.4 (0.1-21.0) months, nine cases experienced restenosis at a median time of 40 (4-325) days after angioplasty. Conclusions: The UHP BA is safe and effective for the primary treatment of PAS in infants and children with CHD. The success rate is high with a low incidence of severe complications. The predictors of success are a larger balloon/waist ratio and the presence of therapeutic tears. The occurrence of restenosis during follow-up, however, remains a problem. A larger number of cases and longer periods of follow-up are needed for further study.

Development of a robust bioassay of monoclonal antibodies and biosimilars against TNF-α by NF-κB-inducible lentiviral reporter gene.

The tumor necrosis factor alpha (TNF-α)/nuclear factor-kappa B (NF-κB) signaling pathway plays a crucial role in the pathogenesis of inflammatory diseases. Several therapeutic monoclonal antibodies (mAbs) and biosimilars against TNF-α have been developed to treat patients who suffer from inflammatory diseases caused by disordered expression of TNF-α. Hence, quality control of biopharmaceuticals is crucial during research and development. The high-order structure of these complex molecules cannot be entirely identified by physiochemical attributes; however, they can be inferred by observing biological activities. Thus, we developed a U937-based bioassay to determine the biological activities of mAbs and biosimilars against TNF-α using a low-basal NF-κB-inducible lentiviral reporter gene. The reporter gene assay (RGA) can be induced with a high signal-to-noise ratio (SNR) in a short time by TNF-α. Validation of the RGA showed accuracy (% relative standard deviation [RSD] = 4.64%), linearity (r2 = 0.9856), and precision (Interday RSD = 4.6%, between analysts RSD = 3.51%) as well as reasonable specificity and robustness. The measured potency values of a biosimilar to adalimumab were between 90% and 110%. Results showed our RGA is suitable for mAb quality control and lot release, and for evaluation of the biological activity similarity of the biosimilar.

Lentil lectin derived from Lens culinaris exhibit broad antiviral activities against SARS-CoV-2 variants.

The spike (S) protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) mutated continuously and newly emerging variants escape from antibody-mediated neutralization raised great concern. S protein is heavily glycosylated and the glycosylation sites are relatively conserved, thus glycans on S protein surface could be a target for the development of anti-SARS-CoV-2 strategies against variants. Here, we collected 12 plant-derived lectins with different carbohydrate specificity and evaluated their anti-SARS-CoV-2 activity against mutant strains and epidemic variants using a pseudovirus-based neutralization assay. The Lens culinaris-derived lentil lectin which specifically bind to oligomannose-type glycans and GlcNAc at the non-reducing end terminus showed most potent and broad antiviral activity against a panel of mutant strains and variants, including the artificial mutants at N-/O-linked glycosylation site, natural existed amino acid mutants, as well as the epidemic variants B.1.1.7, B.1.351, and P.1. Lentil lectin also showed antiviral activity against SARS-CoV and MERS-CoV. We found lentil lectin could block the binding of ACE2 to S trimer and inhibit SARS-CoV-2 at the early steps of infection. Using structural information and determined N-glycan profile of S trimer, taking together with the carbohydrate specificity of lentil lectin, we provide a basis for the observed broad spectrum anti-SARS-CoV-2 activity. Lentil lectin showed weak haemagglutination activity at 1 mg/mL and no cytotoxicity activity, and no weight loss was found in single injection mouse experiment. This report provides the first evidence that lentil lectin strongly inhibit infection of SARS-COV-2 variants, which should provide valuable insights for developing future anti-SARS-CoV-2 strategies.

[Experimental study on ectopic osteogenesis induced by bone morphogenetic protein 2-derived peptide P24 loaded chitosan-4-thio-butylamidine hydrogel].

Objective: To study the ectopic osteogenesis and biocompatibility of bone morphogenetic protein 2 (BMP-2)-derived peptide P24 loaded chitosan-4-thio-butylamidine (CS-TBA) hydrogel. Methods: First, the CS-TBA/hydroxyapatite (HA) solution was prepared by using chitosan, 2-iminothiolane hydrochloride, and HA. Then, the different amount of P24 peptides were added to the CS-TBA/HA to prepare the CS-TBA/5%P24/HA and CS-TBA/10%P24/HA solutions. Finally, ß-glycerophosphate disodium (ß-GP) was added to the CS-TBA/HA, CS-TBA/5%P24/HA, and CS-TBA/10%P24/HA to prepare the CS-TBA/HA/ß-GP, CS-TBA/5%P24/HA/ß-GP, and CS-TBA/10%P24/HA/ß-GP hydrogels, respectively. Eighteen Sprague Dawley female rats were randomly divided into 3 groups ( n=6), which were injected into the back muscle pouches with equal volume CS-TBA/HA/ß-GP hydrogel (group A), CS-TBA/5%P24/HA/ß-GP hydrogel (group B), and CS-TBA/10%P24/HA/ß-GP hydrogel (group C). The animals were sacrificed at 4 and 8 weeks and conducted micro-CT. The ability of biodegradation and osteogenesis of hydrogl was detected by trabecular thickness (Tb.Th), trabecular number (Tb.N), bone mineral density (BMD), and histological staining (HE and Masson). Results: All the rats in 3 groups survived to the time point of the harvest. Micro-CT results showed that the new bones gradually increased in each group after operation. At the same time, the new bone formation was more obvious in groups B and C than in group A, and with the increase of P24 concentration, new bone formation in group C was much more than that in group B. The Tb.Th, Tb.N, and BMD increased gradually in 3 groups, and the differences between 4 and 8 weeks were significant ( P<0.05) except the Tb.Th in group A. At different time points, the Tb.Th, Tb.N, and BMD were significantly higher in groups B and C than in group A ( P<0.05), and in group C was higher than in group B ( P<0.05), showing significant differences between groups. Histological staining showed that the materials of groups B and C were biodegradable, and the osteogenic effect was increased with the increase of P24 concentration. Conclusion: P24 peptide can improve the ectopic osteogenesis of CS-TBA hydrogel, and the 10% concentration is more effective.

Characterization and evaluation of the Ag+-loaded soy protein isolate-based bactericidal film-forming dispersion and films.

UNLABELLED: This study aims to prepare bactericidal films developed from soy protein isolate (SPI) based film-forming dispersions (FFDs) for use in the food and medical fields. The FFD and films were prepared after the incorporation of different concentrations of AgNO3 as a bactericidal agent. The transparency, tensile strength, and antimicrobial features were evaluated. Structural characterizations were also performed by Fourier transform infrared spectroscopy, scanning electron microscope, and atomic force microscopy analysis. Results showed that the opacity of these FFD was greatly decreased after the incorporation of AgNO3. The SPI-5 film has the largest tensile strength (P < 0.05) compared with that of the other ones. Micro structural imaging analysis showed an increase in the surface irregularities with the addition of AgNO3. The minimum inhibitory concentration of AgNO3 was 336 µg/mL FFD for both Escherichia coli ATCC 25923 and Staphylococcus aureus ATCC 25922. The SPI-AgNO3 films developed from the FFD with the minimal AgNO3 concentration at 336 µg/mL FFD also showed bactericidal effects for both the strains. These results may prove promising for the use of SPI-AgNO3 films in the food or medical industries. PRACTICAL APPLICATION: The films prepared in this study are biodegradable and will be used in medical and food fields.