Multiplexed Antibody Glycosylation Profiling Using Dual Enzyme Digestion and Liquid Chromatography-Triple Quadrupole Mass Spectrometry Method.

Antibody glycosylation plays a crucial role in the humoral immune response by regulating effector functions and influencing the binding affinity to immune cell receptors. Previous studies have focused mainly on the immunoglobulin G (IgG) isotype owing to the analytical challenges associated with other isotypes. Thus, the development of a sensitive and accurate analytical platform is necessary to characterize antibody glycosylation across multiple isotypes. In this study, we have developed an analytical workflow using antibody-light-chain affinity beads to purify IgG, IgA, and IgM from 16 µL of human plasma. Dual enzymes, trypsin and Glu-C, were used during on-bead digestion to obtain enzymatic glycopeptides and protein-specific surrogate peptides. Ultra-high-performance liquid chromatography coupled with triple quadrupole mass spectrometry was used in order to determine the sensitivity and specificity. Our platform targets 95 glycopeptides across the IgG, IgA, and IgM isotypes, as well as eight surrogate peptides representing total IgG, four IgG classes, two IgA classes, and IgM. Four stable isotope-labeled internal standards were added after antibody purification to calibrate the preparation and instrumental bias during analysis. Calibration curves constructed using serially diluted plasma samples showed good curve fitting (R2 > 0.959). The intrabatch and interbatch precision for all the targets had relative standard deviation of less than 29.6%. This method was applied to 19 human plasma samples, and the glycosylation percentages were calculated, which were comparable to those reported in the literature. The developed method is sensitive and accurate for Ig glycosylation profiling. It can be used in clinical investigations, particularly for detailed humoral immune profiling.

Association between depressive symptoms and employment type of Korean workers: the Fifth Korean Working Conditions Survey.

BACKGROUND: This study analyzed the association between depressive symptoms and employment type, by considering both socioeconomic status and job stress factors. METHODS: We analyzed 27,369 participants (13,134 men and 14,235 women) using data from the fifth Korean Working Conditions Survey. The participants were divided into regular and precarious workers. Depressive symptoms were defined using the World Health Organization-5 Well-Being Index. A multivariate logistic regression analysis was performed to assess the association between depressive symptoms and employment type. RESULTS: Of the participants, 71.53% (N = 19578) were regular workers and 28.47% (N = 7791) were precarious workers. The weighted frequencies of participants with depressive symptoms (42.50%) were significantly higher than those of precarious workers (32.54%, p < 0.001). In the univariate and multivariate analyses, precarious workers had a significantly higher risk of depressive symptoms than regular workers (odds ratio [OR] 1.53, 95% confidence interval [CI] 1.42-1.64; OR 1.16, 95% CI 1.07-1.26, respectively). The significant association between depressive symptoms and precarious workers has also been reflected in propensity score matched participants through crude and multivariate analysis (OR 1.54 [95% CI 1.43-1.66] and OR 1.15 [95% CI 1.04-1.26], respectively). CONCLUSIONS: The findings suggest that precarious workers may have a higher risk of depressive symptoms than regular workers. However, this is only a cross-sectional study. Therefore, further study is required to investigate the relevance association between depressive symptoms and employment types.

Single-cell transcriptome analysis reveals the effectiveness of cytokine priming irrespective of heterogeneity in mesenchymal stromal cells.

BACKGROUND AIMS: Mesenchymal stromal cells (MSCs) are recognized as a potential cell-based therapy for regenerative medicine. Short-term inflammatory cytokine pre-stimulation (cytokine priming) is a promising approach to enhance regenerative efficacy of MSCs. However, it is unclear whether their intrinsic heterogenic nature causes an unequal response to cytokine priming, which might blunt the accessibility of clinical applications. METHODS: In this study, by analyzing the single-cell transcriptomic landscape of human bone marrow MSCs from a naïve to cytokine-primed state, we elucidated the potential mechanism of superior therapeutic potential in cytokine-primed MSCs. RESULTS: We found that cytokine-primed MSCs had a distinct transcriptome landscape. Although substantial heterogeneity was identified within the population in both naïve and primed states, cytokine priming enhanced the several characteristics of MSCs associated with therapeutic efficacy irrespective of heterogeneity. After cytokine-priming, all sub-clusters of MSCs possessed high levels of immunoregulatory molecules, trophic factors, stemness-related genes, anti-apoptosis markers and low levels of multi-lineage and senescence signatures, which are critical for their therapeutic potency. CONCLUSIONS: In conclusion, our results provide new insights into MSC heterogeneity under cytokine stimulation and suggest that cytokine priming reprogrammed MSCs independent of heterogeneity.

A randomized controlled trial using surgical gloves to prevent chemotherapy-induced peripheral neuropathy by paclitaxel in breast cancer patients (AIUR trial).

BACKGROUND: Chemotherapy-induced peripheral neuropathy (CIPN) is a common adverse effect of taxane treatment and can significantly affect patient quality of life. Currently, there are no effective treatments to alleviate symptoms of CIPN; thus, starting with prevention steps in high-risk patients is considered advantageous. However, for these prevention steps to be applicable to all patients, their side effects or accompanying discomforts should be minimal, and the intervention cost-effective. Compression therapy can be considered a prevention intervention, and using surgical gloves is feasible and cost-effective (approximately $0.6 per pair). Although previous studies on compression therapy using surgical gloves have reported decreased incidence of PN, these studies were non-randomized, limited to nab-paclitaxel treatment, and involved the use of small gloves, which may have caused discomfort. Therefore, this study aimed to assess the preventive effects of compression therapy using normal-sized surgical gloves on CIPN in patients treated with paclitaxel. METHODS: This clinical trial is designed to evaluate the preventive effects of compression therapy using surgical gloves on CIPN in women with stage II-III breast cancer who received paclitaxel chemotherapy for at least 12 weeks. This multicenter, randomized-controlled, open-label study will be conducted in six academic hospitals. Patients with medication or a medical history related to neuropathy or hand disease will be excluded. The primary outcome will be the preventive effect of compression therapy using surgical gloves, measured based on changes in the neurotoxicity component of the Functional Assessment of Cancer Therapy-Taxane questionnaire. Furthermore, we will assess the National Cancer Institute's Common Terminology Criteria for Adverse Events grade of CIPN after 6 months. Notably, the estimated sample size, based on a p-value < 0.025 and statistical power of 0.9, will consist of 104 patients (52 per group), accounting for a 10% sample loss. DISCUSSION: This intervention can be easily implemented in clinical practice and may serve as a preventive strategy for CIPNs with strong patient adherence. If successful, this intervention could improve the quality of life and treatment adherence in patients receiving chemotherapy that can induce PN, extending beyond paclitaxel treatment alone. TRIAL REGISTRATION: ClinicalTrials.gov, NCT05771974; Registered on March 16, 2023.

Microporous Hemostatic Sponge Based on Silk Fibroin and Starch with Increased Structural Retentivity for Contact Activation of the Coagulation Cascade.

Hemostatic agents with diverse forms and materials are necessitated to control excessive bleeding to improve surgical site visibility during operation. The adequate use of hemostatic agents dramatically reduces the chance of dehydration, absence of oxygen, and, in severe cases, death. Polysaccharide-based hemostatic agents are widely used as they are safe for the human body. Among diverse polysaccharides, starch has exhibited a high swelling ability, but its powder formulation is limited during incompressible bleeding. Herein, starch was blended with silk protein and crosslinked using glycerol to improve structural integrity. The silk/starch solution was lyophilized to be a sponge with interconnected pores, which is beneficial to blood coagulation by increased swelling ratio and underwater retentivity to absorb blood plasma. The surface contact between the blood component and the sponge initiates clotting by intrinsic pathway activation and platelet activation without the hemolytic effect or cytotoxicity. The clinical effectiveness of the sponges as topical hemostatic agents was confirmed by animal bleeding model tests.

MicroRNA and Messenger RNA Expression Profiles in Canine Mammary Gland Tumor.

Canine mammary gland tumor (CMT) is the most frequently diagnosed neoplasm in intact female dogs. As prognosis depends on the malignancy of tumors and metastasis levels, early and accurate diagnosis are crucial for prolongation of life expectancy. The genetic similarity of dogs with humans in addition to environmental and physiological similarities make them ideal models for the study of cancer. In this study, we analyzed differentially expressed microRNAs followed by RNA-Seq to investigate the alterations in mRNA levels based on the malignancy (benign, malignant) and the biopsy locations (tumors, surrounding normal tissues). We identified multiple breast cancer-related genes regardless of malignancy. We found cfa-miR-503 to be the only miRNA that showed altered expression in response to malignancy in CMTs. Although further validation is needed, cfa-miR-503 could be used as a potential diagnostic biomarker as well as a potential RNA-based anti-tumor drug in malignant CMTs.

Tuning Selective Transport of Biomolecules through Site-Mutated Nucleoporin-like Protein (NLP) Hydrogels.

Natural selective filtering systems (e.g., the extracellular matrix, nuclear pores, and mucus) separate molecules selectively and efficiently, and the detailed understanding of transport mechanisms exploited in these systems provides important bioinspired design principles for selective filters. In particular, nucleoporins consist of consensus repeat sequences that are readily utilized for engineering repeat proteins. Here, the consensus repeat sequence of Nsp1, a yeast nucleoporin, is polymerized to form a nucleoporin-like protein (NLP) and mutated to understand the effect of sequence on selective transport. The hydrophilic spacers of the NLPs were redesigned considering net charge, charge distribution, and polarity. Mutations were made near to and far from the FSFG interacting domain to explore the role of highly conserved residues as a function of spatial proximity. A nuclear transport receptor-cargo complex, nuclear transport factor 2-green fluorescent protein (NTF2-GFP), was used as a model for changes in transport. For mutations of the charged spacer, some mutations of highly conserved charged residues were possible without knocking out selective transport of the NTF2, but the formation of regions of clustered negative charge has an unfavorable effect on nuclear transporter permeation. Thus, positive net charge and alternating positive and negative charge within the hydrophilic spacer are advantageous for recognition and selective transport. In the polarity panel, mutations that increased the interaction between NTF2-GFP and the gel led to decreased permeation of the NTF2-GFP due to blocking of the interface and inability of the NTF2-GFP to transport into the gel. Therefore, these results provide a strategy for tuning selective permeability of biomolecules using the artificially designed consensus repeat-based hydrogels.

Rapid Weight Change Over Time Is a Risk Factor for Adverse Outcomes in Patients With Predialysis Chronic Kidney Disease: A Prospective Cohort Study.

OBJECTIVE: Both obesity and being underweight are risk factors for adverse outcomes in chronic kidney disease (CKD) patients. However, the effects of longitudinal weight changes on patients with predialysis CKD have not yet been studied. In this study, we analyzed the effects of weight change over time on the adverse outcomes in predialysis CKD population. METHODS: Longitudinal data from a multicenter prospective cohort study (KNOW-CKD) were analyzed. In a total of 2,022 patients, the percent weight change per year were calculated using regression analysis and the study subjects were classified into five categories: group 1, ≤ -5%/year; group 2, -5< to ≤ -2.5%/year; group 3, -2.5< to <2.5%/year; group 4, 2.5≤ < 5%/year; and group 5, ≥5%/year. The incidences of end-stage renal disease (ESRD) and the composite outcome of cardiovascular disease (CVD) and death were calculated in each group and compared to group 3 as reference. RESULTS: During a median 4.4 years of follow-up, 414 ESRD, and 188 composite of CVD and mortality events occurred. Both weight gain and loss were independent risk factors for adverse outcomes. There was a U-shaped correlation between the degree of longitudinal weight change and ESRD (hazard ratio 3.61, 2.15, 1.86 and 3.66, for group 1, 2, 4 and 5, respectively) and composite of CVD and death (hazard ratio 2.92, 2.15, 1.73 and 2.54, respectively), when compared to the reference group 3. The U-shape correlation was most prominent in the subgroup of estimated glomerular filtration rate <45 mL/min/1.73 m2. CONCLUSION: Both rapid weight gain and weight loss are associated with high risk of adverse outcomes, particularly in the advanced CKD.

Primary Autologous Osteochondral Transfer Shows Superior Long-Term Outcome and Survival Rate Compared With Bone Marrow Stimulation for Large Cystic Osteochondral Lesion of Talus.

PURPOSE: To compare the results of bone marrow stimulation (BMS) versus autologous osteochondral transfer (AOT) as primary surgical option for large cystic osteochondral lesion of talus (OLT) and to further distinguish factors associated with clinical failures and overall survival. METHODS: We retrospectively analyzed patients with symptomatic large cystic OLT (>300 mm3) who underwent either primary BMS or AOT between January 2001 and January 2016 with a minimum follow-up of 36 months. Lesion surface area and volume were measured on magnetic resonance imaging. Clinical outcomes were assessed using pain visual analog scale (VAS), American Orthopaedic Foot and Ankle Society (AOFAS) score, and Foot and Ankle Outcome Score (FAOS). Survival outcomes and factors associated with clinical failures were evaluated using Kaplan-Meier analysis and Cox regression analyses, respectively. RESULTS: Fifty of the total 853 patients had large cystic OLTs. Thirty-two patients underwent primary BMS, and 18 patients underwent primary AOT. Mean follow-up period was 118 months, and average lesion surface area and volume were 152.8 mm2 and 850.7 mm3, respectively. The primary AOT group showed significantly superior improvements in clinical outcomes compared with the BMS group at last follow-up (P = .001). Fourteen patients in the primary BMS group and 2 patients in the primary AOT group experienced clinical failure. Kaplan-Meier analysis showed a superior survival rate of primary AOT (P = .042). Syndesmosis widening (hazard ratio 12.361; P = .004) and large lesion surface area (hazard ratio 1.011; P = .014) were significant relative risks of clinical failure in the primary BMS group. However, lesion volume showed no significant relationship with clinical failure. CONCLUSION: Long-term results of primary AOT showed superior clinical improvements and survival rate in treating large cystic OLT. Risk factors for failure in the primary BMS group were large lesion surface area and syndesmosis widening. STUDY DESIGN: Retrospective comparative study LEVEL OF EVIDENCE: III.

The association between urinary bisphenol A levels and nonalcoholic fatty liver disease in Korean adults: Korean National Environmental Health Survey (KoNEHS) 2015-2017.

BACKGROUND: Nonalcoholic fatty liver disease (NAFLD) is becoming a global health problem. Bisphenol A (BPA), one of most widely used environmental chemicals, is suspected to be a contributor to the development NAFLD. This study was performed to examine the relationship between human BPA levels and risk of NAFLD. METHODS: The data (n = 3476 adults: 1474 men and 2002 women) used in this study were obtained from the Korean National Environmental Health Survey III (2015-2017). BPA levels were measured in urine samples. NAFLD was defined using hepatic steatosis index after exclusion of other causes of hepatic diseases. RESULTS: There was a significant linear relationship between the elevated urinary BPA concentrations and risk of NAFLD. In a univariate analysis, odds ratio (OR) of the highest quartile of urinary BPA level was 1.47 [95% confidence interval (CI) 1.11-1.94] compared to the lowest quartile. After adjusted with covariates, the ORs for NAFLD in the third and fourth quartiles were 1.31 [95% CI 1.03-1.67] and 1.32 [95% CI 1.03-1.70], respectively. CONCLUSIONS: Urinary BPA levels are positively associated with the risk of NAFLD in adults. Further experimental studies are needed to understand the molecular mechanisms of BPA on NAFLD prevalence.

Glycoprotein Mimics with Tunable Functionalization through Global Amino Acid Substitution and Copper Click Chemistry.

Glycoproteins and their mimics are challenging to produce because of their large number of polysaccharide side chains that form a densely grafted protein-polysaccharide brush architecture. Herein a new approach to protein bioconjugate synthesis is demonstrated that can approach the functionalization densities of natural glycoproteins through oligosaccharide grafting. Global amino acid substitution is used to replace the methionine residues in a methionine-enriched elastin-like polypeptide with homopropargylglycine (HPG); the substitution was found to replace 93% of the 41 methionines in the protein sequence as well as broaden and increase the thermoresponsive transition. A series of saccharides were conjugated to the recombinant protein backbones through copper(I)-catalyzed alkyne-azide cycloaddition to determine reactivity trends, with 83-100% glycosylation of HPGs. Only an acetyl-protected sialyllactose moiety showed a lower level of 42% HPG glycosylation that is attributed to steric hindrance. The recombinant glycoproteins reproduced the key biofunctional properties of their natural counterparts such as viral inhibition and lectin binding.

Main duct and mixed type intraductal papillary mucinous neoplasms without enhancing mural nodules: Duct diameter of less than 10 mm and segmental dilatation of main pancreatic duct are findings support surveillance rather than immediate surgery.

OBJECTIVE: The guidelines for pancreatic intraductal papillary mucinous neoplasms (IPMNs) recommend surgical resection of all main-duct (MD) and mixed-type IPMNs in surgically fit patients. We conducted this study to identify the rates of high-grade dysplasia (HGD) and invasive carcinoma according to the morphological features of the main pancreatic duct (MPD) in patients with MD and mixed IPMN. METHODS: We performed a retrospective study of 259 patients with histologically proven MD and mixed-type IPMNs who underwent surgery at six academic institutions. RESULTS: The rate of HGD and invasive carcinoma was 11.1% (24/216) in patients without enhancing mural nodules (MNs) and 69.8% (30/43) in patients with MNs. Multivariate analysis showed that MPD diameter of ≥10 mm [odds ratio (OR), 2.5; 95% confidence interval (CI), 1.155-5.505; P = 0.02], diffuse MPD dilatation (OR, 3.2; 95% CI, 1.152-8.998; P = 0.02), and presence of enhancing MNs in MPD (OR, 9.6; 95% CI, 3.928-23.833, P < 0.0001) were significant predictors of HGD and invasive carcinoma. Of the 216 patients without enhancing MNs, 79 patients (36.6%) having both segmental MPD dilatation and MPD diameter of <10 mm showed significantly lower rates of HGD and invasive carcinoma (3/79, 3.8%) than patients having both diffuse MPD dilatation and MPD diameter ≥10 mm (9/36, 25%, P = 0.001). CONCLUSIONS: MD and mixed-type IPMNs having segmental MPD dilatation with MPD dilation <10 mm and no enhancing MNs on imaging showed a significantly lower rate of HGD and invasive carcinoma, and watchful follow-up instead of immediate surgical resection might be possible in these patients.

Nucleopore-Inspired Polymer Hydrogels for Selective Biomolecular Transport.

Biological systems routinely regulate biomolecular transport with remarkable specificity, low energy input, and simple mechanisms. Here, the biophysical mechanisms of nuclear transport inspire the development of gels for recognition and selective permeation (GRASP). GRASP presents a new paradigm for specific transport and selective permeability, in which binding interactions between a biomolecule and a hydrogel lead to faster penetration of the gel. A molecular transport theory identifies key principles for selective transport: entropic repulsion of noninteracting molecules and affinity-mediated diffusion of multireceptor biomolecules through a walking mechanism. The ability of interacting molecules to walk through hydrogels enables enhanced permeability in polymer networks. To realize this theoretical prediction in a novel material, GRASP is engineered from a poly(ethylene glycol) network (entropic barrier) containing antibody-binding oligopeptides (affinity domains). GRASP is synthesized using simultaneous bioconjugation and polycondensation reactions. The elastic modulus, characteristic pore size, biomolecular diffusivity, and selective permeability are measured in the resulting materials, which are applied to regulate the transport of equally sized molecules by preferentially transporting a monoclonal antibody from a polyclonal mixture. Overall, this work presents rationally designed, nucleopore-inspired hydrogels that are capable of controlling biomolecular transport.

Biomimetic repeat protein derived from Xenopus tropicalis for fibrous scaffold fabrication.

Collagen, silk, and elastin are the fibrous proteins consist of representative amino acid repeats. Because these proteins exhibited distinguishing mechanical properties, they have been utilized in diverse applications, such as fiber-based sensors, filtration membranes, supporting materials, and tissue engineering scaffolds. Despite their infinite prevalence and potential, most studies have only focused on a few repeat proteins. In this work, the hypothetical protein with a repeat motif derived from the frog Xenopus tropicalis was obtained and characterized for its potential as a novel protein-based material. The codon-optimized recombinant frog repeat protein, referred to as 'xetro', was produced at a high rate in a bacterial system, and an acid extraction-based purified xetro protein was successfully fabricated into microfibers and nanofibers using wet spinning and electrospinning, respectively. Specifically, the wet-spun xetro microfibers demonstrated about 2- and 1.5-fold higher tensile strength compared with synthetic polymer polylactic acid and cross-linked collagen, respectively. In addition, the wet-spun xetro microfibers showed about sevenfold greater stiffness than collagen. Therefore, the mass production potential and greater mechanical properties of the xetro fiber may result in these fibers becoming a new promising fiber-based material for biomedical engineering.

Mechanically Durable and Biologically Favorable Protein Hydrogel Based on Elastic Silklike Protein Derived from Sea Anemone.

As biodegradable scaffolds, protein hydrogels have considerable potential, particularly for bioartificial organs and three-dimensional space-filling materials. However, their low strength and stiffness have been considered to be limitations for enduring physiological stimuli. Therefore, protein hydrogels have been commonly utilized as delivery vehicles rather than as supporting materials. In this work, sea anemone tentacle-derived recombinant silk-like protein (aneroin) was evaluated as a potential material for a mechanically durable protein hydrogel. Inspired by the natural hardening mechanism, photoinitiated dityrosine cross-linking was employed to fabricate an aneroin hydrogel. It was determined that the fabricated aneroin hydrogel was approximately 10-fold stiffer than mammalian cardiac or skeletal muscle. The aneroin hydrogel provided not only structural support but also an adequate environment for cells. It exhibited an adequate swelling ability and microstructure, which are beneficial for facilitating mass transport and cell proliferation. Based on its mechanical and biological properties, this aneroin hydrogel could be used in various biomedical applications, such as cell-containing patches, biomolecule carriers, and artificial extracellular matrices.

Multifunctional adhesive silk fibroin with blending of RGD-bioconjugated mussel adhesive protein.

Silk has recently been exploited in various fields due to its superior mechanical properties. However, this material's lack of biological functions and relatively poor biodegradation have hindered its wide use in applications related to cells and tissues. Here, we improved the overall characteristics of silkworm silk fibroin (SF) by introduction of RGD peptide-fused recombinant mussel adhesive protein (MAP-RGD). Simple blending of MAP-RGD provided not only bulk-scale adhesive ability but also microscale adhesiveness to cells and various biomolecules. MAP-RGD-blended SF fibers supported enhanced adhesion, proliferation, and spreading of mammalian cells as well as the efficient attachment of biomolecules, including carbohydrate and protein. In addition, the hydrophilicity, swelling, and biodegradability of the MAP-RGD-blended SF material were improved without notable hampering of the original mechanical properties of SF. Therefore, the adhesive silk fibrous scaffold could be successfully used in diverse biomedical engineering applications.

Sex-Specific Association between Sodium Intake Estimated by 24-Hour Urinary Sodium Excretion and Nonalcoholic Fatty Liver Disease: The Community-Based Prospective Cohort Study.

Evidence for the association between high sodium intake and the onset of nonalcoholic fatty liver disease (NAFLD) is insufficient. This study examined the sex-specific association between sodium intake and the risk of NAFLD. This study included 2582 adults (aged 40-69 years; 1011 males and 1571 females). The total sodium excreted over 24 h was estimated from spot urine specimens using Tanaka's equation. Based on these estimates, participants were categorized into three groups according to their 24-h urinary sodium excretion levels: lowest (T1), middle (T2), and highest (T3). In addition, the participants were divided into non-NAFLD (≤36) and NAFLD (>36) groups based on the hepatic steatosis index. During the follow-up period (14 years), NAFLD was observed in 551 participants. The estimated 24-h urinary sodium excretion levels were positively associated with the incidence of NAFLD in all subjects. Upon sex stratification, females in the T2 and T3 groups exhibited adjusted hazard ratios of 1.35 and 1.51, respectively, compared with the T1 group. However, a significant relationship was not observed in males. High intake of sodium, especially among females, may be an important factor contributing to the development of NAFLD. Individuals with high sodium intake should be appropriately counselled and monitored for the risk of NAFLD.

Short-term exposure to di(2-ethylhexyl)phthalate may disrupt hepatic lipid metabolism through modulating the oxidative stress in male adolescent rats.

Di(2-ethylhexyl)phthalate (DEHP) is commonly used to increase the flexibility of plastics. In our previous study, DEHP may increase hepatic lipid accumulation through modulating of acyl-CoA:diacylglycerol acyltransferase 1 (DGAT1) expression. Nevertheless, it is hard to understand the association between DEHP and DGAT1 in the liver because only one dosage of DEHP was used. Thus, this study performed to investigate the role of DGAT1 on hepatic lipid metabolism after various dosages of DEHP exposure. Four-week-old male Sprague-Dawley rats (n = 5/group) were administered corn oil (vehicle) or DEHP (0.75, 7.5, 15, or 150 mg/kg/day) once daily for seven days. DEHP 150 mg/kg/day treated group increased body weight gain and relative liver weight compared to the control (P = 0.044 and P = 0.049, respectively). In histological observation, elevation of hepatic lipid accumulation was observed in all DEHP-treated groups, except DEHP 150 mg/kg/day, compared to that in the control (all P < 0.001). Portal inflammatory infiltration and acidophilic bodies were observed in the liver at DEHP 7.5 mg/kg/day and above treated groups. In addition, malondiadehyde levels, a marker of lipid peroxidation, in the liver were increased in DEHP 7.5, 15 and 150 mg/kg/day compared to the control (P = 0.017, P = 0.001, and P = 0.002, respectively). The expression of Dgat1 in the liver was significantly increased in DEHP 7.5, 15 and 150 mg/kg/day compared to the control group (P = 0.019, P = 0.002, and P < 0.001, respectively); however, there were no significant changes in the protein levels. Therefore, excessive oxidative stress caused by DEHP may induce liver damage such as inflammation rather than hepatic lipid accumulation by regulating DGAT1 transcription.

Photo-/thermo-responsive bioink for improved printability in extrusion-based bioprinting.

Extrusion-based bioprinting has demonstrated significant potential for manufacturing constructs, particularly for 3D cell culture. However, there is a greatly limited number of bioink candidates exploited with extrusion-based bioprinting, as they meet the opposing requirements for printability with indispensable rheological features and for biochemical functionality with desirable microenvironment. In this study, a blend of silk fibroin (SF) and iota-carrageenan (CG) was chosen as a cell-friendly printable material. The SF/CG ink exhibited suitable viscosity and shear-thinning properties, coupled with the rapid sol-gel transition of CG. By employing photo-crosslinking of SF, the printability with Pr value close to 1 and structural integrity of the 3D constructs were significantly improved within a matter of seconds. The printed constructs demonstrated a Young's modulus of approximately 250 kPa, making them suitable for keratinocyte and myoblast cell culture. Furthermore, the high cell adhesiveness and viability (maximum >98%) of the loaded cells underscored the considerable potential of this 3D culture scaffold applied for skin and muscle tissues, which can be easily manipulated using an extrusion-based bioprinter.

Silver nitrate-assisted photo-crosslinking for enhancing the mechanical properties of an alginate/silk fibroin-based 3D scaffold.

Scaffolds play a pivotal role in tissue engineering and serve as vital biological substitutes, providing structural support for cell adhesion and subsequent tissue development. An ideal scaffold must possess mechanical properties suitable for tissue function and exhibit biodegradability. Although synthetic polymer scaffolds offer high rigidity and elasticity owing to their reactive side groups, which facilitate tailored mechanical and rheological properties, they may lack biological cues and cause persistent side effects during degradation. To address these challenges, natural polymers have garnered attention owing to their inherent bioactivity and biocompatibility. However, natural polymers such as silk fibroin (SF) and tyramine-modified alginate (AT) have limitations, including uncontrolled mechanical properties and weak structural integrity. In this study, we developed a blend of SF and AT as a printable biomaterial for extrusion-based 3D printing. Using photocrosslinkable SF/AT inks facilitated the fabrication of complex scaffolds with high printability, thereby enhancing their structural stability. The incorporation of silver nitrate facilitated the tunability of mechanical and rheological behaviors. SF/AT scaffolds with varying stiffness in the physiologically relevant range for soft tissues (51-246 kPa) exhibited excellent biocompatibility, indicating their promising potential for diverse applications in tissue engineering.