In situ crosslinkable multi-functional and cell-responsive alginate 3D matrix via thiol-maleimide click chemistry.

In vivo, cells interact with the extracellular matrix (ECM), which provides a multitude of biophysical and biochemical signals that modulate cellular behavior. Inspired by this, we explored a new methodology to develop a more physiomimetic polysaccharide-based matrix for 3D cell culture. Maleimide-modified alginate (AlgM) derivatives were successfully synthesized using DMTMM to activate carboxylic groups. Thiol-terminated cell-adhesion peptides were tethered to the hydrogel network to promote integrin binding. Rapid and efficient in situ hydrogel formation was promoted by thiol-Michael addition "click" chemistry via maleimide reaction with thiol-flanked protease-sensitive peptides. Alginate derivatives were further ionically crosslinked by divalent ions present in the medium, which led to greater stability and allowed longer cell culture periods. By tailoring alginate's biofunctionality we improved cell-cell and cell-matrix interactions, providing an ECM-like 3D microenvironment. We were able to systematically and independently vary biochemical and biophysical parameters to elicit specific cell responses, creating custom-made 3D matrices. DMTMM-mediated maleimide incorporation is a promising approach to synthesizing AlgM derivatives that can be leveraged to produce ECM-like matrices for a broad range of applications, from in vitro tissue modeling to tissue regeneration.

Long-Term Maintenance of Viable Human Endometrial Epithelial Cells to Analyze Estrogen and Progestin Effects.

There are fewer investigations conducted on human primary endometrial epithelial cells (HPEECs) compared to human primary endometrial stromal cells (HPESCs). One of the main reasons is the scarcity of protocols enabling prolonged epithelial cell culture. Even though it is possible to culture HPEECs in 3D over a longer period of time, it is technically demanding. In this study, we successfully established a highly pure, stable, and long-term viable human conditionally reprogrammed endometrial epithelial cell line, designated as eCRC560. These cells stained positive for epithelial markers, estrogen and progesterone receptors, and epithelial cell-cell contacts but negative for stromal and endothelial cell markers. Estradiol (ES) reduced the abundance of ZO-1 in a time- and dose-dependent manner, in contrast to the dose-dependent increase with the progestin dienogest (DNG) when co-cultured with HPESCs. Moreover, ES significantly increased cell viability, cell migration, and invasion of the eCRC560 cells; all these effects were inhibited by pretreatment with DNG. DNG withdrawal led to a significantly disrupted monolayer of eCRC560 cells in co-culture with HPESCs, yet it markedly increased the adhesion of eCRC560 to the human mesothelial MeT-5A cells. The long-term viable eCRC560 cells are suitable for in vitro analysis of HPEECs to study the epithelial compartment of the human endometrium and endometrial pathologies.

Cell-adhesive double network self-healing hydrogel capable of cell and drug encapsulation: New platform to construct biomimetic environment with bottom-up approach.

This study presents the development and characterization of a novel double-network self-healing hydrogel based on N-carboxyethyl chitosan (CEC) and oxidized dextran (OD) with the incorporation of crosslinked collagen (CEC-OD/COL-GP) to enhance its biological and physicochemical properties. The hydrogel formed via dynamic imine bond formation exhibited efficient self-healing within 30 min, and a compressive modulus recovery of 92 % within 2 h. In addition to its self-healing ability, CEC-OD/COL-GP possesses unique physicochemical characteristics including transparency, injectability, and adhesiveness to various substrates and tissues. Cell encapsulation studies confirmed the biocompatibility and suitability of the hydrogel as a cell-culture scaffold, with the presence of a collagen network that enhances cell adhesion, spreading, long-term cell viability, and proliferation. Leveraging their unique properties, we engineered assemblies of self-healing hydrogel modules for controlled spatiotemporal drug delivery and constructed co-culture models that simulate angiogenesis in tumor microenvironments. Overall, the CEC-OD/COL-GP hydrogel is a versatile and promising material for biomedical applications, offering a bottom-up approach for constructing complex structures with self-healing capabilities, controlled drug release, and support for diverse cell types in 3D environments. This hydrogel platform has considerable potential for advancements in tissue engineering and therapeutic interventions.

4-META/MMA-TBB resin containing nano hydroxyapatite induces the healing of periodontal tissue repair in perforations at the pulp chamber floor.

We aimed to evaluate the materials based on 4-methacryloxyethyl trimellitate anhydride/methyl methacrylate tri-n-butylborane (Super-bond [SB]) and nano hydroxyapatite (naHAp) for the repair of perforation at pulp chamber floor (PPF) in vitro and in vivo models. SB and naHAp were mixed in the mass ratio of 10% or 30% to produce naHAp/SB. Human periodontal ligament stem cells (HPDLSCs) were cultured on resin discs of SB or naHAp/SB to analyze the effects of naHAp/SB on cell adhesion, proliferation, and cementoblastic differentiation. A rat PPF model was treated with SB or naHAp/SB to examine the effects of naHAp/SB on the healing of defected cementum and periodontal ligament (PDL) at the site of PPF. HPDLSCs were spindle-shaped and adhered to all resin discs. Changing the resin from SB to naHAp/SB did not significantly alter cell proliferation. Both 10% and 30% naHAp/SB were more effective than SB in promoting cementoblastic differentiation of HPDLSCs. In the rat PPF model, 30% naHAp/SB was more effective than SB in promoting the formation Sharpey's fiber-like structures with expression of the PDL-related marker and cementum-like structures with expression of cementum-related markers. In conclusion, 30% naHAp/SB can be the new restorative material for PPF because it exhibited the abilities of adhering to dentin and healing of defected periodontal tissue.

Mechanically robust and personalized silk fibroin-magnesium composite scaffolds with water-responsive shape-memory for irregular bone regeneration.

The regeneration of critical-size bone defects, especially those with irregular shapes, remains a clinical challenge. Various biomaterials have been developed to enhance bone regeneration, but the limitations on the shape-adaptive capacity, the complexity of clinical operation, and the unsatisfied osteogenic bioactivity have greatly restricted their clinical application. In this work, we construct a mechanically robust, tailorable and water-responsive shape-memory silk fibroin/magnesium (SF/MgO) composite scaffold, which is able to quickly match irregular defects by simple trimming, thus leading to good interface integration. We demonstrate that the SF/MgO scaffold exhibits excellent mechanical stability and structure retention during the degradative process with the potential for supporting ability in defective areas. This scaffold further promotes the proliferation, adhesion and migration of osteoblasts and the osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) in vitro. With suitable MgO content, the scaffold exhibits good histocompatibility, low foreign-body reactions (FBRs), significant ectopic mineralisation and angiogenesis. Skull defect experiments on male rats demonstrate that the cell-free SF/MgO scaffold markedly enhances bone regeneration of cranial defects. Taken together, the mechanically robust, personalised and bioactive scaffold with water-responsive shape-memory may be a promising biomaterial for clinical-size and irregular bone defect regeneration.

Janus Nanofibrous Patch with In Situ Grown Superlubricated Skin for Soft Tissue Repair with Inhibited Postoperative Adhesion.

The patch with a superlubricated surface shows great potential for the prevention of postoperative adhesion during soft tissue repair. However, the existing patches suffer from the destruction of topography during superlubrication coating and lack of pro-healing capability. Herein, we demonstrate a facile and versatile strategy to develop a Janus nanofibrous patch (J-NFP) with antiadhesion and reactive oxygen species (ROS) scavenging functions. Specifically, sequential electrospinning is performed with initiators and CeO2 nanoparticles (CeNPs) embedded on the different sides, followed by subsurface-initiated atom transfer radical polymerization for grafting zwitterionic polymer brushes, introducing superlubricated skin on the surface of single nanofibers. The poly(sulfobetaine methacrylate) brush-grafted patch retains fibrous topography and shows a coefficient of friction of around 0.12, which is reduced by 77% compared with the pristine fibrous patch. Additionally, a significant reduction in protein, platelet, bacteria, and cell adhesion is observed. More importantly, the CeNPs-embedded patch enables ROS scavenging as well as inhibits pro-inflammatory cytokine secretion and promotes anti-inflammatory cytokine levels. Furthermore, the J-NFP can inhibit tissue adhesion and promote repair of both rat skin wounds and intrauterine injuries. The present strategy for developing the Janus patch exhibits enormous prospects for facilitating soft tissue repair.

Development of Biocompatible Electrospun PHBV-PLLA Polymeric Bilayer Composite Membranes for Skin Tissue Engineering Applications.

Bilayer electrospun fibers aimed to be used for skin tissue engineering applications were fabricated for enhanced cell attachment and proliferation. Different ratios of PHBV-PLLA (70:30, 80:20, and 90:10 w/w) blends were electrospun on previously formed electrospun PHBV membranes to produce their bilayers. The fabricated electrospun membranes were characterized with FTIR, which conformed to the characteristic peaks assigned for both PHBV and PLLA. The surface morphology was evaluated using SEM analysis that showed random fibers with porous morphology. The fiber diameter and pore size were measured in the range of 0.7 ± 0.1 µm and 1.9 ± 0.2 µm, respectively. The tensile properties of the bilayers were determined using an electrodynamic testing system. Bilayers had higher elongation at break (44.45%) compared to the monolayers (28.41%) and improved ultimate tensile strength (7.940 MPa) compared to the PHBV monolayer (2.450 MPa). In vitro cytotoxicity of each of the scaffolds was determined via culturing MC3T3 (pre-osteoblastic cell line) on the membranes. Proliferation was evaluated using the Alamar Blue assay on days 3, 7, and 14, respectively. SEM images of cells cultured on membranes were taken in addition to bright field imaging to visually show cell attachment. Fluorescent nuclear staining performed with DAPI was imaged with an inverted fluorescent microscope. The fabricated bilayer shows high mechanical strength as well as biocompatibility with good cell proliferation and cell attachment, showing potential for skin substitute applications.

Biological Effects of PMMA and Composite Resins on Human Gingival Fibroblasts: An In Vitro Comparative Study.

The use of temporary resin for provisional restorations is a fundamental step to maintain the position of prepared teeth, to protect the pulpal vitality and the periodontal health as well as the occlusion. The present study aimed at evaluating the biological effects of two resins used in dentistry for temporary restorations, Coldpac (Yates Motloid) and ProTemp 4™ (3M ESPE ™), and their eluates, in an in vitro model of human gingival fibroblasts (hGFs). The activation of the inflammatory pathway NFκB p65/NLRP3/IL-1ß induced by the self-curing resin disks was evaluated by real-time PCR, Western blotting and immunofluorescence analysis. The hGFs adhesion on resin disks was investigated by means of inverted light microscopy and scanning electron microscopy (SEM). Our results suggest that hGF cells cultured in adhesion and with eluate derived from ProTemp 4™ (3M ESPE ™) resin evidenced a downregulation in the expression of the inflammatory mediators such as NFκB p65, NLRP3 and IL-1ß compared to the cells cultured with Coldpac (Yates Motloid) after 24 h and 1 week of culture. Furthermore, the cells cultured with ProTemp 4™ (3M ESPE ™) after 24 h and 1 week of culture reported a higher cell viability compared to the cells cultured with Coldpac (Yates Motloid), established by MTS cell analysis. Similar results were obtained when hGFs were placed in culture with the eluate derived from ProTemp 4™ (3M ESPE ™) resin which showed a higher cell viability compared to the cells cultured with eluate derived from Coldpac (Yates Motloid). These results highlighted the lower pro-inflammatory action and improved cell biocompatibility of ProTemp 4™ (3M ESPE ™), suggesting a better performance in terms of cells-material interaction.

Vikil 20 Suppresses the Proliferation of Prostate Cancer (PC-3) Cells and Quenches Free Radicals In Vitro.

Vikil 20 is an herbal formula produced in Ghana and is widely marketed as a product to boost immunity as well as for general well-being. However, the pharmacological effect of this herbal preparation has not been proven scientifically. Therefore, this study was aimed at investigating the antioxidative as well as the anti-prostate cancer effects of the product. To assess the antioxidative effect of Vikil 20, the DPPH and ABTS activities were investigated. The total phenolic content was investigated using the Folin-Ciocalteu method. The cytotoxic effect of Vikil 20 against prostate cancer (PC-3) cells as well as normal (RAW 264.7) cells was investigated using the MTT assay whereas its anti-metastatic effect was analyzed using the cell migration assay. The effect of Vikil 20 on cell adhesion was analyzed via the cell adhesion assay whereas its effect on TNF-α secretion was investigated using a TNF-α detection kit. Vikil 20 demonstrated significant antioxidant effects by suppressing 57.61% and 92.88% respectively of DPPH and ABTS radicals at 1000 µg/mL with total phenolic contents of 140.45 mg GAE/g. Vikil 20 suppressed the proliferation of PC-3 cells by reducing the number of viable cells to 49.5% while sparing the RAW, 264.7 cells. Further, Vikil 20 significantly suppressed both cellular migration and adhesion of prostate cancer cells. Finally, suppression of cellular migration and adhesion is associated with a reduction in TNF-α secretion by PC-3 cells. Taken together, Vikil 20 was found to possess significant antioxidant and anti-prostate cancer effects in vitro.

Loading rutin on surfaces by the layer-by-layer assembly technique to improve the oxidation resistance and osteogenesis of titanium implants in osteoporotic rats.

The purpose of this study was to construct a rutin-controlled release system on the surface of Ti substrates and investigate its effects on osteogenesis and osseointegration on the surface of implants. The base layer, polyethylenimine (PEI), was immobilised on a titanium substrate. Then, hyaluronic acid (HA)/chitosan (CS)-rutin (RT) multilayer films were assembled on the PEI using layer-by-layer (LBL) assembly technology. We used scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy and contact angle measurements to examine all Ti samples. The drug release test of rutin was also carried out to detect the slow-release performance. The osteogenic abilities of the samples were evaluated by experiments on an osteoporosis rat model and MC3T3-E1 cells. The results (SEM, FTIR and contact angle measurements) all confirmed that the PEI substrate layer and HA/CS-RT multilayer film were effectively immobilised on titanium. The drug release test revealed that a rutin controlled release mechanism had been successfully established. Furthermore, thein vitrodata revealed that osteoblasts on the coated titanium matrix had greater adhesion, proliferation, and differentiation capacity than the osteoblasts on the pure titanium surface. When MC3T3-E1 cells were exposed to H2O2-induced oxidative stressin vitro, cell-based tests revealed great tolerance and increased osteogenic potential on HA/CS-RT substrates. We also found that the HA/CS-RT coating significantly increased the new bone mass around the implant. The LBL-deposited HA/CS-RT multilayer coating on the titanium base surface established an excellent rutin-controlled release system, which significantly improved osseointegration and promoted osteogenesis under oxidative stress conditions, suggesting a new implant therapy strategy for patients with osteoporosis.

Effects of Sodium Nitroprusside on Lipopolysaccharide-Induced Inflammation and Disruption of Blood-Brain Barrier.

In various neurodegenerative conditions, inflammation plays a significant role in disrupting the blood-brain barrier (BBB), contributing to disease progression. Nitric oxide (NO) emerges as a central regulator of vascular function, with a dual role in inflammation, acting as both a pro- and anti-inflammatory molecule. This study investigates the effects of the NO donor sodium nitroprusside (SNP) in protecting the BBB from lipopolysaccharide (LPS)-induced inflammation, using bEnd.3 endothelial cells as a model system. Additionally, Raw 264.7 macrophages were employed to assess the effects of LPS and SNP on their adhesion to a bEnd.3 cell monolayer. Our results show that LPS treatment induces oxidative stress, activates the JAK2/STAT3 pathway, and increases pro-inflammatory markers. SNP administration effectively mitigates ROS production and IL-6 expression, suggesting a potential anti-inflammatory role. However, SNP did not significantly alter the adhesion of Raw 264.7 cells to bEnd.3 cells induced by LPS, probably because it did not have any effect on ICAM-1 expression, although it reduced VCAM expression. Moreover, SNP did not prevent BBB disruption. This research provides new insights into the role of NO in BBB disruption induced by inflammation.

Pharmacological Blockade of the Adenosine A2B Receptor Is Protective of Proteinuria in Diabetic Rats, through Affecting Focal Adhesion Kinase Activation and the Adhesion Dynamics of Podocytes.

Induction of the adenosine receptor A2B (A2BAR) expression in diabetic glomeruli correlates with an increased abundance of its endogenous ligand adenosine and the progression of kidney dysfunction. Remarkably, A2BAR antagonism protects from proteinuria in experimental diabetic nephropathy. We found that A2BAR antagonism preserves the arrangement of podocytes on the glomerular filtration barrier, reduces diabetes-induced focal adhesion kinase (FAK) activation, and attenuates podocyte foot processes effacement. In spreading assays using human podocytes in vitro, adenosine enhanced the rate of cell body expansion on laminin-coated glass and promoted peripheral pY397-FAK subcellular distribution, while selective A2BAR antagonism impeded these effects and attenuated the migratory capability of podocytes. Increased phosphorylation of the Myosin2A light chain accompanied the effects of adenosine. Furthermore, when the A2BAR was stimulated, the cells expanded more broadly and more staining of pS19 myosin was detected which co-localized with actin cables, suggesting increased contractility potential in cells planted onto a matrix with a stiffness similar to of the glomerular basement membrane. We conclude that A2BAR is involved in adhesion dynamics and contractile actin bundle formation, leading to podocyte foot processes effacement. The antagonism of this receptor may be an alternative to the intervention of glomerular barrier deterioration and proteinuria in the diabetic kidney disease.

Erianin alleviates LPS-induced acute lung injury via antagonizing P-selectin-mediated neutrophil adhesion function.

ETHNOPHARMACOLOGICAL RELEVANCE: Dendrobium officinale Kimura et Migo, known as "Tiepi Shihu" in traditional Chinese medicine, boasts an extensive history of medicinal use documented in the Chinese Pharmacopoeia. "Shen Nong Ben Cao Jing" records D. officinale as a superior herbal medicine for fortifying "Yin" and invigorating the five viscera. Erianin, a benzidine compound, emerges as a prominent active constituent derived from D. officinale, with the pharmacological efficacy of D. officinale closely linked to the anti-inflammatory properties of erianin. AIM OF THE STUDY: Acute lung injury (ALI) is a substantial threat to global public health, while P-selectin stands out as a promising novel target for treating acute inflammatory conditions. This investigation aims to explore the therapeutic potential of erianin in ALI treatment and elucidate the underlying mechanisms. EXPERIMENTAL DESIGN: The effectiveness of erianin in conferring protection against ALI was investigated through comprehensive histopathological and biochemical analyses of lung tissues and bronchoalveolar lavage fluid (BALF) in an in vivo model of LPS-induced ALI in mice. The impact of erianin on fMLP-induced neutrophil chemotaxis was quantitatively assessed using the Transwell and Zigmond chamber, respectively. To determine the therapeutic target of erianin and elucidate their binding capability, a series of sophisticated assays were employed, including drug affinity responsive target stability (DARTS) assay, cellular thermal shift assay (CETSA), and molecular docking analyses. RESULTS: Erianin demonstrated a significant alleviation of LPS-induced acute lung injury, characterized by reduced total cell and neutrophil counts and diminished total protein contents in BALF. Moreover, erianin exhibited a capacity to decrease proinflammatory cytokine production in both lung tissues and BALF. Notably, erianin effectively suppressed the activation of NF-κB signaling in the lung tissues of LPS- challenged mice; however, it did not exhibit in vitro inhibitory effects on inflammation in LPS-induced human pulmonary microvascular endothelial cells (HPMECs). Additionally, erianin blocked the adhesion and rolling of neutrophils on HPMECs. While erianin did not influence endothelial P-selectin expression or cytomembrane translocation, it significantly reduced the ligand affinity between P-selectin and P-selectin glycoprotein ligand-1 (PSGL-1). CONCLUSIONS: Erianin inhibits P-selectin-mediated neutrophil adhesion to activated endothelium, thereby alleviating ALI. The present study highlights the potential of erianin as a promising lead for ALI treatment.

Laminin-associated integrins mediate Diffuse Intrinsic Pontine Glioma infiltration and therapy response within a neural assembloid model.

Diffuse Intrinsic Pontine Glioma (DIPG) is a highly aggressive and fatal pediatric brain cancer. One pre-requisite for tumor cells to infiltrate is adhesion to extracellular matrix (ECM) components. However, it remains largely unknown which ECM proteins are critical in enabling DIPG adhesion and migration and which integrin receptors mediate these processes. Here, we identify laminin as a key ECM protein that supports robust DIPG cell adhesion and migration. To study DIPG infiltration, we developed a DIPG-neural assembloid model, which is composed of a DIPG spheroid fused to a human induced pluripotent stem cell-derived neural organoid. Using this assembloid model, we demonstrate that knockdown of laminin-associated integrins significantly impedes DIPG infiltration. Moreover, laminin-associated integrin knockdown improves DIPG response to radiation and HDAC inhibitor treatment within the DIPG-neural assembloids. These findings reveal the critical role of laminin-associated integrins in mediating DIPG progression and drug response. The results also provide evidence that disrupting integrin receptors may offer a novel therapeutic strategy to enhance DIPG treatment outcomes. Finally, these results establish DIPG-neural assembloid models as a powerful tool to study DIPG disease progression and enable drug discovery.

Shizukaol C alleviates trimethylamine oxide-induced inflammation through activating Keap1-Nrf2-GSTpi pathway in vascular smooth muscle cell.

BACKGROUND: Cardiovascular disease is one of the main causes of global mortality, and there is an urgent need for effective treatment strategies. Gut microbiota-dependent metabolite trimethylamine-N-oxide (TMAO) promotes the development of cardiovascular diseases, and shizukaol C, a natural sesquiterpene isolated from Chloranthus multistachys with various biological activities, might exhibit beneficial role in preventing TMAO-induced vascular inflammation. PURPOSE: The purpose of this study was to investigate the anti-inflammatory effects and the underlying mechanisms of shizukaol C on TMAO-induced vascular inflammation. METHODS: The effect and underlying mechanism of shizukaol C on TMAO-induced adhesion molecules expression, bone marrow-derived macrophages (BMDM) adhesion to VSMC were evaluated by western blot, cell adhesion assay, co-immunoprecipitation, immunofluorescence assay, and quantitative Real-Time PCR, respectively. To verify the role of shizukaol C in vivo, TMAO-induced vascular inflammation model were established using guidewire-induced injury on mice carotid artery. Changes in the intima area and the expression of GSTpi, VCAM-1, CD68 were examined using haematoxylin-eosin staining, and immunofluorescence assay. RESULTS: Our data demonstrated that shizukaol C significantly suppressed TMAO-induced adhesion molecule expression and the bone marrow-derived macrophages (BMDM) adhesion in vascular smooth muscle cells (VSMC). Mechanically, shizukaol C inhibited TMAO-induced c-Jun N-terminal kinase (JNK)-nuclear factor-kappa B (NF-κB)/p65 activation, and the JNK inhibition was dependent on the shizukaol C-mediated glutathione-S-transferase pi (GSTpi) expression. By further molecular docking and protein-binding analysis, we demonstrated that shizukaol C directly binds to Keap1 to induce Nrf2 nuclear translocation and upregulated GSTpi expression. Consistently, our in vivo experiment showed that shizukaol C elevated the expression level of GSTpi in carotid arteries and alleviates TMAO-induced vascular inflammation. CONCLUSION: Shizukaol C exerts anti-inflammatory effects in TMAO-treated VSMC by targeting Keap1 and activating Nrf2-GSTpi signaling and resultantly inhibits the downstream JNK-NF-κB/p65 activation and VSMC adhesion, and alleviates TMAO-induced vascular inflammation in vivo, suggesting that shizukaol C may be a potential drug for treating TMAO-induced vascular diseases.

The diazirine-mediated photo-crosslinking of collagen improves biomaterial mechanical properties and cellular interactions.

In tissue engineering, crosslinking with carbodiimides such as EDC is omnipresent to improve the mechanical properties of biomaterials. However, in collagen biomaterials, EDC reacts with glutamate or aspartate residues, inactivating the binding sites for cellular receptors and rendering collagen inert to many cell types. In this work, we have developed a crosslinking method that ameliorates the rigidity, stability, and degradation rate of collagen biomaterials, whilst retaining key interactions between cells and the native collagen sequence. Our approach relies on the UV-triggered reaction of diazirine groups grafted on lysines, leaving critical amino acid residues intact. Notably, GxxGER recognition motifs for collagen-binding integrins, ablated by EDC crosslinking, were left unreacted, enabling cell attachment, spreading, and colonization on films and porous scaffolds. In addition, our procedure conserves the architecture of biomaterials, improves their resistance to collagenase and cellular contraction, and yields material stiffness akin to that obtained with EDC. Importantly, diazirine-crosslinked collagen can host mesenchymal stem cells, highlighting its strong potential as a substrate for tissue repair. We have therefore established a new crosslinking strategy to modulate the mechanical features of collagen porous scaffolds without altering its biological properties, thereby offering an advantageous alternative to carbodiimide treatment. STATEMENT OF SIGNIFICANCE: This article describes an approach to improve the mechanical properties of collagen porous scaffolds, without impacting collagen's natural interactions with cells. This is significant because collagen crosslinking is overwhelmingly performed using carbodiimides, which results in a critical loss of cellular affinity. By contrast, our method leaves key cellular binding sites in the collagen sequence intact, enabling cell-biomaterial interactions. It relies on the fast, UV-triggered reaction of diazirine with collagen, and does not produce toxic by-products. It also supports the culture of mesenchymal stem cells, a pivotal cell type in a wide range of tissue repair applications. Overall, our approach offers an attractive option for the crosslinking of collagen, a prominent material in the growing field of tissue engineering.

Parkin Enhances Gefitinib-induced Anoikis in HeLa Cervical Cancer Cells.

BACKGROUND/AIM: Gefitinib exhibits anticancer activity against cervical cancer cells via anoikis, a type of apoptosis induced by cell detachment from the extracellular matrix. Previous studies have reported that Parkin expression affects the efficacy of anticancer drugs. However, the impact of Parkin expression on the therapeutic effects of gefitinib in human cervical cancer remains unclear. Thus, this study aimed to evaluate whether Parkin over-expression improves the therapeutic effects of gefitinib against HeLa cervical cancer cells. MATERIALS AND METHODS: Cell viability and apoptotic death of HeLa cells were measured by trypan blue dye exclusion assay and flow cytometry. Cell detachment, adhesion, spreading, and cell-cell interaction were observed by inverted microscopy. Alteration of adhesion-related molecules was evaluated by confocal microscopy and western blot assay. RESULTS: Parkin expression potentiated gefitinib-induced cell detachment by affecting the organization of the actin cytoskeleton. In addition, Parkin expression induced a further reduction in the reattachment of and interaction between detached cells. The therapeutic efficacy of low-dose gefitinib combined with Parkin expression was equivalent to that of high-dose gefitinib alone. CONCLUSION: Parkin expression promotes gefitinib-induced anoikis, consequently increasing the efficacy of gefitinib against HeLa human cervical cancer cells. Based on our results, we propose that Parkin can be used to increase the anti-cancer effect of gefitinib on cervical cancer cells.

Biological evaluation of sulfonate and sulfate analogues of lithocholic acid: A bioisosterism-guided approach towards the discovery of potential sialyltransferase inhibitors for antimetastatic study.

The naturally occurring bile acid lithocholic acid (LCA) has been a crucial core structure for many non-sugar-containing sialyltranferase (ST) inhibitors documented in literature. With the aim of elucidating the impact of the terminal carboxyl acid substituent of LCA on its ST inhibition, in this present study, we report the (bio)isosteric replacement-based design and synthesis of sulfonate and sulfate analogues of LCA. Among these compounds, the sulfate analogue SPP-002 was found to selectively inhibit N-glycan sialylation by at least an order of magnitude, indicating a substantial improvement in both potency and selectivity when compared to the unmodified parent bile acid. Molecular docking analysis supported the stronger binding of the synthetic analogue in the enzyme active site. Treatment with SPP-002 also hampered the migration, adhesion, and invasion of MDA-MB-231 cells in vitro by suppressing the expression of signaling proteins involved in the cancer metastasis-associated integrin/FAK/paxillin pathway. In totality, these findings offer not only a novel structural scaffold but also valuable insights for the future development of more potent and selective ST inhibitors with potential therapeutic effects against tumor cancer metastasis.

Self-Assembling Triple-Helix Recombinant Collagen Hydrogel Enriched with Tyrosine.

The self-assembly of collagen within the human body creates a complex 3D fibrous network, providing structural integrity and mechanical strength to connective tissues. Recombinant collagen plays a pivotal role in the realm of biomimetic natural collagen. However, almost all of the reported recombinant collagens lack the capability of self-assembly, severely hindering their application in tissue engineering and regenerative medicine. Herein, we have for the first time constructed a series of self-assembling tyrosine-rich triple helix recombinant collagens, mimicking the structure and functionality of natural collagen. The recombinant collagen consists of a central triple-helical domain characterized by the (Gly-Xaa-Yaa)n sequence, along with N-terminal and C-terminal domains featuring the GYY sequence. The introduction of GYY has a negligible impact on the stability of the triple-helical structure of recombinant collagen while simultaneously promoting its self-assembly into fibers. In the presence of [Ru(bpy)3]Cl2 and APS as catalysts, tyrosine residues in the recombinant collagen undergo covalent cross-linking, resulting in a hydrogel with exceptional mechanical properties. The recombinant collagen hydrogel exhibits outstanding biocompatibility and bioactivity, significantly enhancing the proliferation, adhesion, migration, and differentiation of HFF-1 cells. This innovative self-assembled triple-helix recombinant collagen demonstrates significant potential in the fields of tissue engineering and medical materials.

In vitro and in vivo exposure of endothelial cells to dibutyl phthalate promotes monocyte adhesion.

The effect of endothelial cells' exposure to dibutyl phthalate (DBP) on monocyte adhesion is largely unknown. We evaluated monocyte adhesion to DBP-exposed endothelial cells by combining three approaches: short-term exposure (24 h) of EA.hy926 cells to 10-6, 10-5, and 10-4 M DBP, long-term exposure (12 weeks) of EA.hy926 cells to 10-9, 10-8, and 10-7 M DBP, and exposure of rats (28 and 90 days) to 100, 500, and 5000 mg DBP/kg food. Monocyte adhesion to human EA.hy926 and rat aortic endothelial cells, expression of selected cellular adhesion molecules and chemokines, and the involvement of extracellular signal-regulated kinase 1/2 (ERK1/2) were analyzed. We observed increased monocyte adhesion to DBP-exposed EA.hy926 cells in vitro and to rat aortic endothelium ex vivo. ERK1/2 inhibitor prevented monocyte adhesion to DBP-exposed EA.hy926 cells in short-term exposure experiments. Increased ERK1/2 phosphorylation in rat aortic endothelium and transient decrease in ERK1/2 activation following long-term exposure of EA.hy926 cells to DBP were also observed. In summary, exposure of endothelial cells to DBP promotes monocyte adhesion, thus suggesting a possible role for this phthalate in the development of atherosclerosis. ERK1/2 signaling could be the mediator of monocyte adhesion to DBP-exposed endothelial cells, but only after short-term high-level exposure.