Membrane Arrays Research Articles

CD44s and CD44v8-10 isoforms confer acquired resistance to osimertinib by activating the ErbB3/STAT3 signaling pathway

AimsAlthough epidermal growth factor receptor (EGFR)-mutant lung cancers respond well to osimertinib, acquired resistance to osimertinib eventually develops through EGFR-dependent and EGFR-independent resistance mechanisms. CD44 splicing variants are widely expressed in lung cancer tissues. However, it remains unclear whether specific splicing variants are involved in acquired resistance to osimertinib. Main methodsThe real-time PCR was performed to measure the expression levels of total CD44 and specific CD44 splicing variants (CD44s or CD44v). Gene knockdown and restoration were performed to investigate the effects of CD44 splicing variants on osimertinib sensitivity. Activation of the signaling pathway was evaluated using receptor-tyrosine-kinase phosphorylation membrane arrays, co-immunoprecipitation, and western blotting. Key findingsClinical analysis demonstrated that the expression level of total CD44 increased in primary cancer cells from lung adenocarcinomas patients after the development of acquired resistance to osimertinib. Furthermore, osimertinib-resistant cells showed elevated levels of either the CD44s variant or CD44v variants. Manipulations of CD44s or CD44v8-10 were performed to investigate their effects on treatment sensitivity to osimertinib. Knockdown of CD44 increased osimertinib-induced cell death in osimertinib-resistant cells. However, restoration of CD44s or CD44v8-10 in CD44-knockdown H1975/AZD-sgCD44 cells induced osimertinib resistance. Mechanically, we showed that ErbB3 interacted with CD44 and was transactivated by CD44, that consequently triggered activation of the ErbB3/STAT3 signaling pathway and led to CD44s- or CD44v8-10-mediated osimertinib resistance. SignificanceCD44 is a co-receptor for ErbB3 and triggers activation of the ErbB3 signaling axis, leading to acquired resistance to osimertinib. CD44/ErbB3 signaling may represent a therapeutic target for overcoming osimertinib resistance.

Fabrication of nanoparticle array membranes by integrating semi-crystalline polymer self-assembly with NIPS for water treatment.

The integration of polymer self-assembly with non-solvent induced phase separation (SNIPS) represents a recent advancement in membrane fabrication. This breakthrough allows for the fabrication of membranes with uniformly sized pores, enabling precise and fast separation through a phase inversion process commonly used in industrial fabrication. Currently, block copolymers are used in implementing the SNIPS strategy. In order to facilitate an easier and more flexible fabrication procedure, we employed the widely used semi-crystalline polymer polyvinylidene fluoride (PVDF) as the base material for achieving SNIPS through self-seeding. This process involves filtering the PVDF casting solution to induce microphase separation and generate crystal seeds. Subsequently, NIPS is applied to enable the growth of crystal seeds into uniformly distributed nanoparticles with consistent size and shape, ultimately resulting in a membrane with a uniform pore size. The fabricated membrane exhibited improved flux (2924.67 ± 28.02 L m-2 h-1 at 0.5 bar) and rejection (91% for 500 nm polystyrene particles). Notably, the microphase separation in the casting solution is a distinguishing feature of the SNIPS compared to NIPS. In this study, we found that the microphase separation of semi-crystalline polymers is also crucial for achieving membranes with uniform pore sizes. This finding may extend the potential application of the SNIPS strategy to include semi-crystalline polymers.

Review of electrospun microtube array membrane (MTAM)-a novel new class of hollow fiber for encapsulated cell therapy (ECT) in clinical applications.

Encapsulated cell therapy (ECT) shows significant potential for treating neurodegenerative disorders including Alzheimer's and Parkinson's, which currently lack curative medicines and must be managed symptomatically. This novel technique encapsulates functional cells with a semi-permeable membrane, providing protection while enabling critical nutrients and therapeutic substances to pass through. Traditional ECT procedures, on the other hand, pose difficulties in terms of cell survival and retrieval. We introduce the Microtube Array Membrane (MTAM), a revolutionary technology that solves these constraints, in this comprehensive overview. Microtube Array Membrane has distinct microstructures that improve encapsulated cells' long-term viability by combining the advantages of macro and micron scales. Importantly, the MTAM platform improves biosafety by allowing the entire encapsulated unit to be retrieved in the event of an adverse reaction. Our findings show that MTAM-based ECT has a great potential in a variety of illness situations. For cancer treatment, hybridoma cells secreting anti-CEACAM 6 antibodies inhibit triple-negative breast cancer cell lines for an extended period of time. In animal brain models of Alzheimer's disease, hybridoma cells secreting anti-pTau antibodies successfully reduce pTau buildup, accompanied by improvements in memory performance. In mouse models, MTAM-encapsulated primary cardiac mesenchymal stem cells dramatically improve overall survival and heart function. These findings illustrate the efficacy and adaptability of MTAM-based ECT in addressing major issues such as immunological isolation, cell viability, and patient safety. We provide new possibilities for the treatment of neurodegenerative illnesses and other conditions by combining the potential of ECT with MTAM. Continued research and development in this subject has a lot of promise for developing cell therapy and giving hope to people suffering from chronic diseases.

Transmembrane coupling of liquid-like protein condensates

Liquid-liquid phase separation of proteins occurs on both surfaces of cellular membranes during diverse physiological processes. In vitro reconstitution could provide insight into the mechanisms underlying these events. However, most existing reconstitution techniques provide access to only one membrane surface, making it difficult to probe transmembrane phenomena. To study protein phase separation simultaneously on both membrane surfaces, we developed an array of freestanding planar lipid membranes. Interestingly, we observed that liquid-like protein condensates on one side of the membrane colocalized with those on the other side, resulting in transmembrane coupling. Our results, based on lipid probe partitioning and mobility of lipids, suggest that protein condensates locally reorganize membrane lipids, a process which could be explained by multiple effects. These findings suggest a mechanism by which signals originating on one side of a biological membrane, triggered by protein phase separation, can be transferred to the opposite side.

Numerical and experimental study on the dynamic equivalent methodology of a membrane antenna structure and a grid membrane structure

The dynamic equivalent methodology utilizing a grid membrane substitute for a planar membrane for vibration test verification on the ground has been demonstrated in small sizes with simple constraints. The method lacks accuracy and validity for a real complex membrane antenna. This paper thus focuses on the applicability of the equivalence approach to a membrane antenna and the factors affecting its dynamic equivalence to verify whether the grid membrane structure can replace the membrane antenna structure for modal identification on the ground. To this end, an experimental system is developed to conduct vibration tests on the grid membrane structure in air, using the grid membrane model with unidirectional tension as a substitute for the membrane array. The connecting strips attach the grid membrane to thin-walled lenticular booms (TWLBs) to allow for unidirectional tension. A laser displacement sensor array is employed to obtain the vibration data. A combination of the Fast Fourier Transfer (FFT) and Stochastic Subspace Identification (SSI) methods is applied to identify the structural frequencies and mode shapes. Vibration tests on the grid membranes with different added masses and tensile forces are conducted. Meanwhile, the numerical results for the rectangular membrane are chosen as a reference for comparison with the experimental results for the grid membrane. In conclusion, the numerical results for the membrane antenna structure and the experimental results for the grid membrane structure show good agreement in terms of frequency and mode shape. Additionally, both the added masses in the intersection areas of the grid membrane and the tensile force have a significant effect on the dynamic equivalence.

Highly enantioseparation in membrane-supported one-dimensional metal–organic framework hollow nanotube array prepared via mussel-inspired chemistry

High-enantioselective chiral metal–organic framework (CMOF) nanochannel membranes are of critical importance for chiral enantiomeric separations by taking advantage of their inherent high porosity and intrinsic chirality. However, traditional chiral membranes are still constrained by the permeability-selectivity trade-off, making it challenging to improve both simultaneously. This study described the structure of a new class of membrane-supported one-dimensional MOF hollow nanotube for transport and separation of chiral 1-phenylethanol (PE), utilizing a biomimetic polydopamine (PDA)-mediated counter-diffusion synthesis strategy. The inner cylindrical pore channel surface of polycarbonate track-etched membranes (PCTM) was modified by PDA chemistry to control the nucleation and interfacial growth of CMOF crystals, leading to the development of integrated chromatographic micro-column array membranes PCTM@PDA@Cu2C2D and PCTM@PDA@Cu2C2B with one-dimensional (1D) CMOF hollow nanochannels. Compared to PCTM@PDA@Cu2C2B, it was highlighted that the chiral membrane PCTM@PDA@Cu2C2D possessed the higher loading of Cu2C2D functional layer and more suitable steric chiral microenvironment, thus exhibited more outstanding permeability and selectivity for S-PE enantiomer with an enantiomeric excess value up to 90 % under an optimal guest concentration of 250 ppm at 30 °C for 1 h. The chiral membrane with 1D MOF hollow nanotubes, created by applying a gentle and simple method to introduce CMOF into the surface and pore channels of the substrate membrane, was expected to be utilized for the large-scale production of chiral separation membranes for industrial applications.

Activate the filtration capability of 3.5 nm ultra-large pores and eliminate the requirement of pore homogeneity for carbon nanotube array membranes

Vertical array carbon nanotube (VACNT) membrane is considered as one of the most promising materials for seawater desalination due to its excellent porosity, strong mechanical properties and atomic smoothness of the inner wall. However, in practical applications, the synthesis of highly oriented VACNT arrays with uniform pore sizes (< 1.1 nm) needs to be strictly controlled, and achieving high permeability-retention for large pores (> 1.1 nm) is a great challenge. Here, we use molecular dynamics simulations to introduce the oscillation paradigm into VACNT filtration membranes with a heterogeneous pore network with a wide pore size distribution (ranging from 1 nm to 3.5 nm). Notably, the oscillating heterogeneous VACNT membrane achieved ultra-high permeability of 1421.8 L/cm2/day/MPa (~5 times speed increase in comparison with homogeneous VACNT and ~ 2 times over state-of-the-art CNT membranes), while maintaining a selectivity of 97.5 %. This method activates the filtration capacity of 3.5 nm ultra-large pores, eliminating the requirement for pore homogeneity in VACNT, and achieves the effect of “killing two birds with one stone”. In addition, the filtration performance of specific heterogeneous VACNT membrane was successfully predicted by water permeability curve fitting, which provided valuable theoretical guidance for the design of high-performance VACNT reverse osmosis desalination system.

Study of the structure and electrical properties of graphene oxide (GO) and graphene oxide+nanocellulose (GO+NC)

Proton exchange membranes (PEMs) that function at elevated temperatures surpassing 100°C and exhibit exceptional mechanical, chemical, and thermochemical stability have garnered significant interest. This is primarily due to their practical utility in proton exchange membrane fuel cells (PEMFCs). In the present era, an extensive array of polymers and polymer-blended membranes have been scrutinized for their applicability in this domain. Each of these materials presents a set of advantages and disadvantages. However, the realm of PEMFCs is still in search of the perfect membrane endowed with distinct properties. Graphene oxide, a two-dimensional substance arising from the oxidation of graphite, has manifested itself as a promising candidate. Oxygen (O) functional groups are incorporated within the sp2 carbon (C) plane of the oxidized graphite, forming graphene oxide. This material can be synthesized by exfoliating graphite oxide, a three-dimensional carbon-based compound, into layered sheets using ultrasonic or mechanical agitation. The presence of multiple reactive oxygen functional groups renders graphene oxide suitable for a diverse array of applications, such as composite polymers, energy conversion materials, environmental safeguards, sensors, transistors, and optical components. This versatility is attributable to its outstanding electrical, mechanical, and thermal properties. Among the various methodologies for graphene oxide synthesis, the modified Hammer method stands out for its simplicity, cost-effectiveness, and high yield. This research delves into the structural analysis of graphene oxide obtained through the Hammer method, utilizing commercially available graphite. The study involves the creation of membranes based on carboxymethylcellulose (NC) that integrate dispersed graphene oxide (GO) sheets. These novel membranes, as well as pristine graphene oxide, were subjected to a comprehensive array of analytical techniques including XRD, XPS, Raman, FTIR, and SEM microscopy. Additionally, electrophysical characterizations were undertaken employing electrochemical impedance spectroscopy (EIS) measurements. The investigation uncovered that the introduction of NC into the graphene oxide matrix significantly enhances the electron conductivity of the composite membrane. Simultaneously, the presence of graphene oxide contributes to the mechanical robustness and thermomechanical stability of the membrane structure. The principal impetus behind this article lies in furnishing vital insights into the physical and structural attributes of graphene oxide membranes relevant to their deployment in hydrogen energy applications.

Enhanced Osmotic Energy Conversion through an Asymmetric Nanochannel Array Membrane with an Ultrathin Selective Layer

Enhanced Osmotic Energy Conversion through an Asymmetric Nanochannel Array Membrane with an Ultrathin Selective Layer

Rimonabant and Cannabidiol Rewrite the Interactions between Breast Cancer Cells and Tumor Microenvironment.

The spread of breast cancer to distant sites is the major cause of death in breast cancer patients. Increasing evidence supports the role of the tumor microenvironment (TME) in breast cancers, and its pathologic assessment has become a diagnostic and therapeutic tool. In the TME, a bidirectional interplay between tumor and stromal cells occurs, both at the primary and metastatic site. Hundreds of molecules, including cytokines, chemokines, and growth factors, contribute to this fine interaction to promote tumor spreading. Here, we investigated the effects of Rimonabant and Cannabidiol, known for their antitumor activity, on reprogramming the breast TME. Both compounds directly affect the activity of several pathways involved in breast cancer progression. To mimic tumor-stroma interactions during breast-to-lung metastasis, we investigated the effect of the compounds on growth factor secretion from metastatic breast cancer cells and normal and activated lung fibroblasts. In this setting, we demonstrated the anti-metastatic potential of the two compounds, and the membrane array analyses highlighted their ability to alter the release of factors involved in the autocrine and paracrine regulation of tumor proliferation, angiogenesis, and immune reprogramming. The results enforce the antitumor potential of Rimonabant and Cannabidiol, providing a novel potential tool for breast cancer TME management.

Unveiling the Power of Anticancer Drug Screening: A Clinical Case Study Comparing the Effectiveness of Hollow Fiber Assay Microtube Array Membrane (MTAM-HFA) in Breast Cancer Patients.

Breast cancer is a severe public health problem, and early treatment with powerful anticancer drugs is critical for success. The researchers investigated the clinical results of a novel screening tool termed Microtube Array Membrane Hollow Fiber Assay (MTAM-HFA) in breast cancer patients in this clinical investigation. In all trial participants, the MTAM-HFA was utilized to identify active medicines for the treatment of breast cancer. The MTAM-HFA was shown to be extremely useful in predicting patient response to anticancer medication therapy in this study. Furthermore, the substantial association between the MTAM-HFA screening outcome and the clinical outcome of the respective patients emphasizes the promise of this unique screening technology in discovering effective anticancer medication combinations for the treatment of breast cancer. These findings indicate that the MTAM-HFA has clinical significance and might be a valuable tool in the development of tailored therapy for cancer care. This study provides helpful information for physicians and scientists working on breast cancer therapy research. The potential benefits of employing MTAM-HFA to find accurate therapies for breast cancer patients might lead to enhanced personalized medicine approaches to cancer care, resulting in better patient outcomes. Overall, the MTAM-HFA screening approach has the potential to revolutionize customized cancer therapy, providing hope to both patients and physicians.

Recovery of homogeneous photocatalysts by covalent organic framework membranes

Transition metal-based homogeneous photocatalysts offer a wealth of opportunities for organic synthesis. The most versatile ruthenium(II) and iridium(III) polypyridyl complexes, however, are among the rarest metal complexes. Moreover, immobilizing these precious catalysts for recycling is challenging as their opacity may obstruct light transmission. Recovery of homogeneous catalysts by conventional polymeric membranes is promising but limited, as the modulation of their pore structure and tolerance of polar organic solvents are challenging. Here, we report the effective recovery of homogeneous photocatalysts using covalent organic framework (COF) membranes. An array of COF membranes with tunable pore sizes and superior organic solvent resistance were prepared. Ruthenium and iridium photoredox catalysts were recycled for 10 cycles in various types of photochemical reactions, constantly achieving high catalytical performance, high recovery rates, and high permeance. We successfully recovered the photocatalysts at gram-scale. Furthermore, we demonstrated a cascade isolation of an iridium photocatalyst and purification of a small organic molecule product with COF membranes possessing different pore sizes. Our results indicate an intriguing potential to shift the paradigm of the pharmaceutical and fine chemical synthesis campaign.

Abstract 4595: STAT-3 chemical inhibition modulates decidual-like polarization in NK cells from PCa patients and restore their anti-tumor activities

Abstract Introduction. Natural Killer (NK) cells are innate lymphoid cells involved in tumour recognition/elimination. NK cells are altered in their phenotype and functions in diverse tumors, including prostate cancer (PCa). We demonstrated that PCa circulating NK cells (TANKs) acquire the pro-angiogenic/decidual-like CD56brightCD9+CD49a+ phenotype, release IL-8 and MMP-9, functionally support endothelial cell activation and secrete monocyte-recruiting/M2-like macrophage-polarizing factors. Materials and methods. Here, we characterized the phenotype of tumour infiltrating NKs (TINKs) and tumour-associated (TANKs) in PCa patients and evaluated the contribution of STAT3, as possible driver of NK cell polarization. PCa TINKs and TANKs were characterized by multicolour flow cytometry (FC) for decidual-like surface markers (CD9, CD49a) and degranulation capabilities (CD107a). STAT3 activation, was investigated in circulating PCa NK cells, by FC. Using a drug-repurposing approach with the antipsychotic agent Pimozide (a chemical inhibitor of STAT3), we modulated STAT3 activation, ex vivo, in PCa TANKs and monitored their secretome changes, by commercially available protein membrane arrays together with their capability to degranulate and produce perforin/GranzymeB. Results and discussion. We observed that PCa TINKs acquire the same CD9+CD49a+ decidual-like NK cell phenotype, as found in PCa TANKs. We detected the presence of CD56brightCD9+CD49a+ decidual-like NK cell also in peripheral blood of subjects with benign prostatic hyperplasia (BPH), but in a lower frequency, compared to those from PCa TANKs. Sera from PCa patients were enriched in IL-4, IL-6, IL-8 and IL-10, all cytokines able to activate STAT3 signalling. We detected increased phosphorylation of STAT3 in PCa TANKs, compared to NK cells from healthy controls, that was reduced following 24 hours of stimulation by Pimozide. This treatment resulted in decreased capabilities of PCa TANKs to secrete pro-angiogenic factors (IL-8, IL-6), molecules involved in monocytes recruitment/M2-like macrophage polarization (CCL-2, CCL5, GM-CSF, IL-10), together with increased degranulation, augmented secretion of (IFN-γ and TNF-α) and increased production of Perforin and Granzyme. Conclusions. Our results suggest that STAT3 inhibition can be envisaged as a potential strategy to limit the generation of pro-angiogenic/decidual-like NKs, while contributing to NK cell re-education in PCa. Citation Format: Matteo Gallazzi, Maria Teresa Palano, Martina Cucchiara, Federico Dehò, Paolo Capogrosso, Francesca Franzi, Fausto Sessa, Angelo Naselli, Lorenzo Mortara, Antonino Bruno. STAT-3 chemical inhibition modulates decidual-like polarization in NK cells from PCa patients and restore their anti-tumor activities. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4595.

Analysis of cytokine profiles in sera of single and multiple infantile hemangioma.

Infantile hemangiomas (IH) are benign vascular tumors that are common in infancy. They vary in growth, size, location, and depth, and although most lesions are relatively small, approximately one fifth of patients have multiple lesions. Risk factors for IH include female sex, low birth weight, multiple gestation, preterm birth, progesterone therapy, and family history, but the mechanism that causes multiple lesions is unclear. We hypothesized that blood cytokines are involved as a cause of multiple IHs, and tried to prove this using sera and membrane arrays from patients with single and multiple IHs. Serum samples were obtained from five patients with multiple lesions and four patients with a single lesion, none of which had received any treatment. Serum levels of 20 cytokines were measured using human angiogenesis antibody membrane array. Four of the 20 cytokines (bFGF, IFN-γ, IGF-I, and TGF-β1) were higher in the patients with multiple lesions than in those with single lesion, with statistically significant difference (p < 0.05). Notably, signal for IFN-γ was evident in all cases with multiple IHs, but was absent in cases with single IH. Although not significant, there was mild correlation between IFN-γ and IGF-I (r=0.64, p=0.065), and between IGF-I and TGF-β1 (r=0.63, p=0.066). bFGF levels were strongly and significantly correlated with the number of lesions (r=0.88, p=0.0020). In conclusion, blood cytokines could act as a cause of multiple IHs. This is a pilot study with a small cohort, so further large-scale studies are necessary.

Anti-proliferative effect of melatonin in human hepatoma HepG2 cells occurs mainly through cell cycle arrest and inflammation inhibition

Hepatocellular carcinoma (HCC) is the major lethal primary liver malignant worldwide. Although, melatonin has various antitumor bioactivities; there is a requirement for more investigations to elucidate the not discussed effects, and the controversial responses of the treatment with melatonin on targets mediated in HCC. To achieve the aim of the present study, HCC-HepG2 cells were treated with different concentrations of melatonin at various time intervals. The selected minimal proliferation inhibition doses of melatonin were then incubated with cells to examine the arresting effect of melatonin on dividing cells using flow cytometry. Furthermore, the molecular patterns of genes that contributed to apoptosis, drug resistance development, antioxidation, and melatonin crossing were quantified by qRT-PCR. Additionally, the Human inflammation antibody array membrane (40 targets) was used to check the anti-inflammatory effect of melatonin. Our results validated that, melatonin shows anti-proliferative action through preserving cells in G0/G1 phase (P < 0.001) that is associated with a highly significant increase in the expression level of the P53 gene (P < 0.01). On contrary, as a novelty, our data recorded decreases in expression levels of genes involved in the pro-apoptotic pathway; with a significant increase (P < 0.05) in the expression level of an anti-apoptotic gene, Bcl2. Interestingly, we detected observed increases in the expression levels of genes responsible for conferring drug resistance including ABCB1, ABCC1, and ABCC5. Our study proved the anti-inflammatory activity of 1 mM melatonin in HCC-HepG2 cells. Accordingly, we can conclude that melatonin facilitates the anti-proliferation of cells at doses of 1 mM, and 2.5 mM after 24 h. This action is initiated through cell cycle arrest at G0/G1 phase via increasing the expression of P53, but independently on apoptosis. Collectively, melatonin is an effective anti-inflammatory and anti-proliferative promising therapy for the treatment of HCC. However, its consumption should be cautious to avoid the development of drug resistance and provide a better treatment strategy.

Screening of EWI-2-Derived Peptides for Targeting Tetraspanin CD81 and Their Effect on Cancer Cell Migration.

CD81, a transmembrane protein belonging to the tetraspanin family, has recently been suggested as a therapeutic target for cancers. Here, we screened peptides that bind to the tetraspanin CD81 protein, and evaluated their inhibitory activity in cancer cell migration. To screen for CD81-binding peptides (CD81-BP), a peptide array membrane was prepared from the amino acid sequence of the EWI-2 protein, a major partner of CD81, before binding to fluorescently labeled CD81. As a result, four candidate CD81-BPs were identified and characterized. In particular, the CFMKRLRK peptide (called P152 in this study) was found to be the best candidate that preferentially binds to the extracellular loop of CD81, with an estimated dissociation constant of 0.91 µM. Since CD81 was reported to promote cancer cell migration, an initial step in metastasis, the Boyden chamber assay, was next performed to assess the effect of CD81-BP candidates on the migration of MDA-MB-231 human breast cancer cells. Interestingly, our result indicated that P152 could suppress MDA-MB-231 cell migration at the level comparable to that of an anti-human CD81 antibody (5A6). Thus, we propose these CD81-BPs with the anti-migration property against cancer cells for the development of novel therapeutic strategies.

Surface roughness modulates EGFR signaling and stemness of triple-negative breast cancer cells.

Introduction: Cancer stem cells (CSC), a major culprit of drug-resistant phenotypes and tumor relapse, represent less than 2 % of the bulk of TNBC cells, making them difficult to isolate, study, and thus, limiting our understanding of the pathogenesis of the disease. Current methods for CSC enrichment, such as 3D spheroid culture, genetic modification, and stem cell conditioning, are time consuming, expensive, and unsuitable for high-throughput assays. One way to address these limitations is to use topographical stimuli to enhance CSC populations in planar culture. Physical cues in the breast tumor microenvironment can influence cell behavior through changes in the mechanical properties of the extracellular matrix (ECM). In this study, we used topographical cues on polystyrene films to investigate their effect on the proteome and stemness of standard TNBC cell lines. Methods: The topographical polystyrene-based array was generated using razor printing and polishing methods. Proteome data were analyzed and enriched bioprocesses were identified using R software. Stemness was assessed measuring CD44, CD24 and ALDH markers using flow cytometry, immunofluorescence, detection assays, and further validated with mammosphere assay. EGF/EGFR expression and activity was evaluated using enzyme-linked immunosorbent assay (ELISA), immunofluorescence and antibody membrane array. A dose-response assay was performed to further investigate the effect of surface topography on the sensitivity of cells to the EGFR inhibitor. Results: Surface roughness enriched the CSC population and modulated epidermal growth factor receptor (EGFR) signaling activity in TNBC cells. Enhanced proliferation of MDA-MB-468 cells in roughness correlated with upregulation of the epidermal growth factor (EGF) ligand, which in turn corresponded with a 3-fold increase in the expression of EGFR and a 42% increase in its phosphorylation compared to standard smooth culture surfaces. The results also demonstrated that phenotypic changes associated with topographical (roughness) stimuli significantly decreased the drug sensitivity to the EGFR inhibitor gefitinib. In addition, the proportion of CD44+/CD24-/ALDH+ was enhanced on surface roughness in both MDA-MB-231 and MDA-MB-468 cell lines. We also demonstrated that YAP/TAZ activation decreased in a roughness-dependent manner, confirming the mechanosensing effect of the topographies on the oncogenic activity of the cells. Discussion: Overall, this study demonstrates the potential of surface roughness as a culture strategy to influence oncogenic activity in TNBC cells and enrich CSC populations in planar cultures. Such a culture strategy may benefit high-throughput screening studies seeking to identify compounds with broader tumor efficacy.

Programmable Physical Properties of Freestanding Chitosan Membranes Electrofabricated in Microfluidics.

Microfluidic-integrated freestanding membranes with suitable biocompatibility and tunable physicochemical properties are in high demand for a wide range of life science and biological studies. However, there is a lack of facile and rapid methods to integrate such versatile membranes into microfluidics. A recently invented interfacial electrofabrication of chitosan membranes offers an in-situ membrane integration strategy that is flexible, controllable, simple, and biologically friendly. In this follow-up study, we explored the ability to program the physical properties of these chitosan membranes by varying the electrofabrication conditions (e.g., applied voltage and pH of alginate). We found a strong association between membrane growth rate, properties, and fabrication parameters: high electrical stimuli and pH of alginate resulted in high optical retardance and low permeability, and vice versa. This suggests that the molecular alignment and density of electrofabricated chitosan membranes could be actively tailored according to application needs. Lastly, we demonstrated that this interfacial electrofabrication could easily be expanded to produce chitosan membrane arrays with higher uniformity than the previously well-established flow assembly method. This study demonstrates the tunability of the electrofabricated membranes' properties and functionality, thus expanding the utility of such membranes for broader applications in the future.

Role of cathepsin D induced by Porphyromonas gingivalis lipopolysaccharide in periodontitis.

Periodontitis is an inflammatory disease of tooth-supporting tissues caused by oral bacteria. Periodontal ligament loss and alveolar bone destruction occur in progressive periodontitis. Since gingival crevicular fluids (GCF) reflects the inflammatory environment of the periodontal pocket, it is a very important specimen for developing targets for periodontitis diagnosis. An antibody array was performed using GCF collected from healthy participants and patients with periodontitis to identify the proteolytic enzymes involved in periodontitis. Of 21 targets on the antibody array membrane, kallikrein 6 (KLK6), kallikrein 10 (KLK10), cathepsin A (CathA), and cathepsin D (CathD) showed higher levels in periodontitis GCF than in GCF from healthy participants. Lipopolysaccharide stimulation of Porphyromonas gingivalis (PG-LPS) in immortalized gingival fibroblasts only increased CathD protein levels among the four targets. The substrate cleavage activity of CathD was increased in PG-LPS-treated immortalized gingival fibroblast extract. The PG-LPS-induced substrate cleavage effect was abolished by the CathD inhibitor pepstatin A. Osteoclast formation was promoted by treatment with conditioned media from PG-LPS- treated immortalized gingival fibroblasts but inhibited by the CathD inhibitor pepstatin A. These results suggest that PG-LPS affected the osteoclast formation process by increasing CathD expression in cells around the alveolar bone, thereby participating in periodontitis progression.

Lateral compression of lipids drives transbilayer coupling of protein condensates.

Protein phase separation that is restricted to a two-dimensional lipid membrane has recently gained much attention due to its involvement in various cellular processes. Two popular in vitro model membrane systems, giant unilamellar vesicles (GUVs) and supported lipid bilayers (SLBs), have been used to study it. However, due to the accessibility to only one side of the membrane in these systems, protein phase separation on both sides of the membrane remains unexplored. Here, we introduce a freestanding planar lipid membrane array as an effective platform to study membrane-associated protein phase separation. Protein condensates on the membrane display liquid-like features, and environmental stimuli, such as salt concentration and temperature, effectively control the observed phase separation results in our system with the application of several intrinsically disordered proteins. Interestingly, we observe transbilayer coupling of protein condensates such that protein-rich domains on one side of the membrane are found to colocalize with those on the other side of the membrane. How do these protein phases communicate across the lipid bilayer? Based on data from lipid probe partitioning and photobleaching experiments, we hypothesize that protein condensation on the membrane exerts lateral compressive stress on the underlying lipids, driving the formation of lipid domains with reduced fluidity. Specifically, lipid domains with reduced fluidity and increased lipid packing, formed by protein condensation on each membrane leaflet, are attracted to one another, leading to transbilayer coupling of protein condensates. These findings suggest a previously unknown mechanism by which cellular signals from one membrane leaflet, triggered by membrane-associated protein phase separation, can be transferred to the opposing leaflet.