Biofabricated poly (γ-glutamic acid) bio-ink reinforced with calcium silicate exhibiting superior mechanical properties and biocompatibility for bone regeneration.

Background/purpose: The modification in 3D hydrogels, tissue engineering, and biomaterials science has enabled us to fabricate novel substitutes for bone regeneration. This study aimed to combine different biomaterials by 3D technique to fabricate a promising all-rounded hydrogel for bone regeneration. Materials and methods: In this study, glycidyl methacrylate (GMA)-modified poly γ-glutamic acid (γ-PGA-GMA) hydrogels with calcium silicate (CS) hydrogel of different concentrations were fabricated by a 3D printing technique, and their biocompatibility and capability in bone regeneration were also evaluated. Results: The results showed that CS γ-PGA-GMA could be successfully fabricated, and the presence of CS enhanced the rheological and mechanical properties of γ-PGA-GMA hydrogels, thus making them more adept at 3D printing and implantations. SEM images of the surface structure showed that higher CS concentrations (5% and 10%) contributed to denser surface architectures, thus achieving improved cellular adhesion and stem cell proliferation. Furthermore, higher concentrations of CS resulted in elevated expressions of osteogenic-related markers such as alkaline phosphatase (ALP) and osteocalcin (OC), as well as enhanced calcium deposition represented by the increased Alizarin Red S staining. In vivo studies referring to critical defects of rabbit femur further showed that the existence of hydrogels alone was able to induce partial bone regeneration, demonstrated by the results from quantitative and qualitative analysis of micro-CT scans. However, CS alterations caused significant increases in bone regeneration, as indicated by micro-CT and histological staining. Conclusion: These results robustly suggest combining different biomaterials is crucial to producing a well-rounded hydrogel for tissue regeneration. We hope this study could be applied as a platform for others to brainstorm potential out-of-the-box solutions, contributing to developing high-potential biomaterials for bone regeneration.

First-trimester urinary extracellular vesicles as predictors of preterm birth: an insight into immune programming.

Background: The programming of innate and adaptive immunity plays a pivotal role in determining the course of pregnancy, leading to either normal term birth (TB) or preterm birth (PB) through the modulation of macrophage (M1/M2) differentiation. Extracellular vesicles (EVs) in maternal blood, harboring a repertoire of physiological and pathological messengers, are integral players in pregnancy outcomes. It is unknown whether urinary EVs (UEVs) could serve as a non-invasive mechanistic biomarker for predicting PB. Methods: This study investigated first-trimester UEVs carrying M1 messengers with altered immune programming, aiming to discern their correlation to subsequent PB. A birth cohort comprising 501 pregnant women, with 40 women experiencing PB matched to 40 women experiencing TB on the same day, was examined. First-trimester UEVs were isolated for the quantification of immune mediators. Additionally, we evaluated the UEV modulation of "trained immunity" on macrophage and lymphocyte differentiations, including mRNA expression profiles, and chromatin activation modification at histone 3 lysine 4 trimethylation (H3K4me3). Results: We found a significant elevation (p < 0.05) in the particles of UEVs bearing characteristic exosome markers (CD9/CD63/CD81/syntenin) during the first trimester of pregnancy compared to non-pregnant samples. Furthermore, UEVs from PB demonstrated significantly heightened levels of MCP-1 (p = 0.003), IL-6 (p = 0.041), IL-17A (p = 0.007), IP-10 (p = 0.036), TNFα (p = 0.004), IL-12 (p = 0.045), and IFNγ (p = 0.030) relative to those from TB, indicative of altered M1 and Th17 differentiation. Notably, MCP-1 (>174 pg/mL) exhibited a sensitivity of 71.9% and specificity of 64.6%, and MCP-1 (>174 pg/mL) and IFNγ (>8.7 pg/mL) provided a higher sensitivity (84.6%) of predicting PB and moderate specificity of 66.7%. Subsequent investigations showed that UEVs from TB exerted a significant suppression of M1 differentiation (iNOS expression) and Th17 differentiation (RORrT expression) compared to those of PB. Conversely, UEVs derived from PB induced a significantly higher expression of chromatin modification at H3K4me3 with higher production of IL-8 and TNFα cytokines (p < 0.001). Implications: This pioneering study provides critical evidence for the early detection of altered M1 and Th17 responses within UEVs as a predictor of PB and early modulation of altered M1 and Th17 polarization associated with better T-cell regulatory differentiation as a potential prevention of subsequent PB.

Oral immunization with cell-free self-assembly virus-like particles against orange-spotted grouper nervous necrosis virus in grouper larvae, Epinephelus coioides.

Nervous necrosis virus (NNV) infection causes viral nervous necrosis, inflicting serious economic losses in marine fish cultivation. Vaccination is the most effective choice for controlling and preventing viral infection. Virus-like particles (VLPs) are considered a novel vaccine platform because they are not infectious and they induce neutralizing antibodies efficiently. In the present study, we investigated the effect of the recombinant orange-spotted grouper NNV (OSGNNV) capsid proteins produced in Escherichia coli and cell-free self-assembled into VLPs on protective immune responses in orange-spotted grouper following immersion, intramuscular injection and oral immunization. We found the OSGNNV VLPs elicited neutralizing antibody with high efficacy, and provided the fish with full protection against OSGNNV challenge. In addition, the cell-free self-assembled OSGNNV VLPs did not contain residual host cell components and was safer compared with the intracellular assembled VLPs. Thus, oral vaccination is a more convenient and preferred route for fish vaccination. Our results show that the fish fed four times with a diet supplemented with 50-200 µg/g OSGNNV VLPs at 7-day intervals have sufficient protection. These findings demonstrate that cell-free self-assembled OSGNNV VLPs have potential as oral vaccines in grouper.

Complete Genome Sequence of Nervous Necrosis Virus Isolated from Orange-Spotted Grouper (Epinephelus coioides) in Taiwan.

The genome sequence of nervous necrosis virus strain KS1 isolated from orange-spotted grouper (Epinephelus coioides) was cloned and analyzed. The viral genome is composed of two single-stranded positive-sense RNA molecules, RNA1 and RNA2. Phylogenetic analysis shows that the virus strain KS1 belongs to the red-spotted grouper nervous necrosis virus genotype.

Nitric oxide production and blood pressure reduction during haemodialysis.

AIM: A decrease of systolic blood pressure in excess of 20 mmHg during haemodialysis treatment (IDD) is common for haemodialysis patients. Intradialytic hypotension (IDH) is symptomatic IDD by definition. Overproduction of nitric oxide (NO) is a possible cause of IDD. Dialysate nitrate and nitrite amount can be used as an indicator of intradialysis NO production. Our aim was to find the predictor of NO production in IDD patients. METHODS: Partial dialysate samples were collected during the whole haemodialysis session and total dialysate nitrate and nitrite amount was measured to assess the association of intradialysis NO production with blood pressure change. RESULTS: There were 31 IDD patients and 71 patients who did not develop IDD (NIDD) included in the study. Among the IDD patients, 13 were IDH patients with a mean systolic blood pressure lower than that of the other 18 symptomless IDD patients (96.6 ± 3.4 mmHg vs 125.0 ± 3.8 mmHg, P<0.001). The median value of NO production was higher in the IDD than in the NIDD patients (447.7 µg vs 238.8 µg, P<0.001). The NO production correlated linearly with blood pressure reduction (R=0.487, P<0.001). The multivariate analysis showed that NO production was positively associated with predialysis systolic blood pressure. CONCLUSION: Nitric oxide production during haemodialysis was higher in IDD than in NIDD patients. IDH often occurred when systolic blood pressure was reduced to below 100 mmHg. The amount of NO produced during haemodialysis, which may be associated with predialysis systolic blood pressure, can be used to predict intradialysis blood pressure decrease.