Affinity For Cells Research Articles

Thallium Induces Antiproliferative and Cytotoxic Activity in Glioblastoma C6 and U373 Cell Cultures via Apoptosis and Changes in Cell Cycle.

Thallium (Tl+) is a heavy metal that causes toxicity in several organs, including the brain. Its cytotoxic profile, combined with its affinity for tumor cells when used as a radioligand for labeling these cells, suggests its potential use as antitumor therapy. In this study, glioblastoma cell lines C6 (from rat) and U373 (from human) were exposed to increased concentrations of thallium(I) acetate (5, 10, 50, 100, or 200µM) and several toxic endpoints were evaluated, including loss of confluence and morphological changes, loss of cell viability, changes in cell cycle, and apoptosis. Tl+ was detected in cells exposed to thallium(I) acetate, demonstrating efficient uptake mechanism. Confluence in both cell lines decreased in a concentration-dependent manner (50-200µM), while morphological changes (cell shrinkage and decreased cell volume) were more evident at exposures to higher Tl+ concentrations. For both parameters, the effects of Tl+ were more prominent in C6 cells compared to U373 cells. The same trend was observed for cell viability, with Tl+ affecting this parameter in C6 cells at low concentrations, whereas U373 cells showed greater resistance, with significant changes observed only at the higher concentrations. C6 and U373 cells treated with Tl+ also showed morphological characteristics corresponding to apoptosis. The cytotoxic effects of Tl+ were also assessed in neural and astrocytic primary cultures from the whole ratbrain. Primary neural and astrocytic cultures were less sensitive than C6 and U373 cells, showing changes in cell viability at 50 and 100µM concentrations, respectively. Cell cycle in both brain tumor cell lines was altered by Tl+ in G1/G2 and S phases. In addition, when combined with temozolamide (500µM), Tl+ elicited cell cycle alterations, increasing SubG1 population. Combined, our novel results characterize and validate the cytotoxic and antiproliferative effects of Tl+ in glioblastoma cells.

A recombinant scFv antibody-based fusion protein that targets EGFR associated with IMPDH2 downregulation and its drug conjugate show therapeutic efficacy against esophageal cancer

The present study aimed to evaluate the anti-tumor efficacy of the epidermal growth factor receptor (EGFR)-targeting recombinant fusion protein Fv-LDP-D3 and its antibody-drug conjugate Fv-LDP-D3-AE against esophageal cancer. Fv-LDP-D3, consisting of the fragment variable (Fv) of an anti-EGFR antibody, the apoprotein of lidamycin (LDP), and the third domain of human serum albumin (D3), exhibited a high binding affinity for EGFR-overexpressing esophageal cancer cells, inhibited EGFR phosphorylation and down-regulated inosine monophosphate dehydrogenase type II (IMPDH2) expression. Fv-LDP-D3 was taken up by cancer cells through intensive macropinocytosis; it inhibited the proliferation and induced the apoptosis of esophageal cancer cells. In vivo imaging revealed that Fv-LDP-D3 displayed specific tumor-site accumulation and a long-lasting retention over a 26-day period. Furthermore, Fv-LDP-D3-AE, a pertinent antibody-drug conjugate prepared by integrating the enediyne chromophore of lidamycin into the Fv-LDP-D3 molecule, displayed highly potent cytotoxicity, inhibited migration and invasion, induced apoptosis and DNA damage, arrested cells at G2/M phase, and caused mitochondrial damage in esophageal cancer cells. More importantly, both of Fv-LDP-D3 and Fv-LDP-D3-AE markedly inhibited the growth of esophageal cancer xenografts in athymic mice at well tolerated doses. The present results indicate that Fv-LDP-D3, and Fv-LDP-D3-AE exert prominent antitumor efficacy associated with targeting EGFR, suggesting their potential as promising candidates for targeted therapy against esophageal cancer.

A strategy of functional crosslinking acellular matrix in blood-contacting implantable devices with recombinant humanized collagen type III (rhCOLIII)

A large number of blood contacting implantable devices are used worldwide annually. Acellular matrix (AM), as one of the blood-contacting materials, has achieved a great success, since it remains the structures, components and certain functions of extracellular matrix. However, AM often fails during the period of service owing to non-ideal anticoagulation , severe inflammatory responses and poor mechanical properties. Herein, we specially prepared a newly designed tailored recombinant humanized collagen type III (rhCOLIII) that effectively removed the binding site to platelets while retaining cytocompatibility. In this study, a radical-polymerization-crosslinked decellularized porcine pericardium (DPP) with rhCOLIII and glycidyl methacrylate (GMA) through one-pot method was designed as artificial heart valves. Due to the introduction of rhCOLIII, the anticoagulation properties were dramatically improved with fewer platelets adhesion and less thrombogenesis. The mechanical properties of the novel heart valve (rhCOLIII/GMA-DPP) were significantly enhanced through radical polymerization crosslinking. Furthermore, experiments in vivo and vitro showed the inflammatory responses were moderately reduced. In conclusion, this study provides a simple strategy for functional crosslinking AM in blood-contacting implantable devices and shows possibilities for real application. • rhCOLIII possess both affinity for endothelial cells and anticoagulation property. • A simply radical polymerization crosslinking method for acellular matrix. • Functional crosslinked acellular matrix with rhCOLIII performs well as heart valves.

An aromatase inhibitor in combination with Zinc(II) phthalocyanine for targeted therapy of post-menopausal breast cancer

As a third-generation steroidal aromatase inhibitor, exemestane (EXE) has been clinically used for postmenopausal advanced breast cancer patients whose condition has progressed after treatment of tamoxifen. However, the further development and application of EXE was limited due to its low solubility and oral bioavailability, inevitable drug resistance and side effects. Based on the unique therapeutic advantages of photodynamic therapy (PDT), a novel aromatase-targeted photosensitizer EX-Pc was synthesized by the combination of EXE and the phthalocyanine photosensitizer. The compound EX-Pc still maintains the superior optical properties of the phthalocyanine photosensitizer upon the introduction of EXE and triethylene glycol chain. Meanwhile, the results of targeted uptake in vitro and in vivo indicated that EX-Pc exhibited high selectivity and affinity for breast cancer cells and tumor tissues, which have the overexpression of aromatase. More importantly, the compound EX-Pc exhibits significant photocytotoxicity and tumor regression ability on breast cancer cells and tumor. In addition, the compound EX-Pc shows negligible side effects and high biological safety. We believe that this is a potential strategy for the treatment of postmenopausal breast cancer.

Is There a Role for Gut Microbiome Dysbiosis in IgA Nephropathy?

Immunoglobulin A nephropathy (IgAN) is the most common primary glomerulonephritis and one of the leading causes of renal failure worldwide. The pathophysiology of IgAN involves nephrotoxic IgA1-immune complexes. These complexes are formed by galactose-deficient (Gd) IgA1 with autoantibodies against the hinge region of Gd-IgA1 as well as soluble CD89, an immune complex amplifier with an affinity for mesangial cells. These multiple molecular interactions result in the induction of the mesangial IgA receptor, CD71, injuring the kidney and causing disease. This review features recent immunological and microbiome studies that bring new microbiota-dependent mechanisms developing the disease based on data from IgAN patients and a humanized mouse model of IgAN. Dysbiosis of the microbiota in IgAN patients is also discussed in detail. Highlights of this review underscore that nephrotoxic IgA1 in the humanized mice originates from mucosal surfaces. Fecal microbiota transplantation (FMT) experiments in mice using stools from patients reveal a possible microbiota dysbiosis in IgAN with the capacity to induce progression of the disease whereas FMT from healthy hosts has beneficial effects in mice. The continual growth of knowledge in IgAN patients and models can lead to the development of new therapeutic strategies targeting the microbiota to treat this disease.

Synthesis of Biotinylated PAMAM G3 Dendrimers Substituted with R-Glycidol and Celecoxib/Simvastatin as Repurposed Drugs and Evaluation of Their Increased Additive Cytotoxicity for Cancer Cell Lines.

Simple SummaryNew anti-cancer drugs can be created through the combination of well-known substances acting on different molecular targets. Repurposed drugs selected in this way can then be attached to special carriers that have specific, high affinity for cancer cells. In this study, two anti-glioma drugs, celecoxib and simvastatin, were chosen and linked to the PAMAM G3 dendrimer targeted to cancer cells by attached biotin and R-glycidol. In vitro studies performed with human glioblastoma (U-118 MG) and squamous cell carcinoma (SCC-15) cells revealed that dendrimer conjugate containing both celecoxib and simvastatin was 20–50 times more potent than either drug administered alone or in combination. Thus, the obtained combined conjugate can be considered as a potential candidate for a new therapy of malignant glioblastoma.Recent achievement in anticancer therapy considers the application of repurposed drugs in optimal combinations with the use of specific carriers for their targeted delivery. As a result, new optimized medications with reduced side effects can be obtained. In this study, two known anticancer drugs, celecoxib and/or simvastatin, were conjugated covalently with PAMAM G3 dendrimer and tested in vitro against human squamous carcinoma (SCC-15-15) and glioblastoma (U-118 MG) cells, as well as normal human fibroblasts (BJ). The obtained conjugates were also substituted with biotin and R-glycidol to increase their affinity for cancer cells and were characterized with NMR spectroscopy and dynamic light scattering technique. Conjugates furnished with two celecoxib and four simvastatin residues revealed the very high effectiveness and dramatically decreased the SCC-15 and U-118 MG cell viability at very low concentrations with IC50 equal to about 3 µM. Its action was 20–50-fold stronger than that of either drug alone or as a mixture. Combined conjugate revealed also additive action since it was 2–8-fold more effective than conjugates with either single drug. The combined conjugate revealed rather low specificity since it was also highly cytotoxic for BJ cells. Despite this, it may be concluded that biotinylated and R-glycidylated PAMAM G3 dendrimers substituted with both celecoxib and simvastatin can be considered as a new perspective anticancer agent, effective in therapy of malignant, incurable glioblastomas.

Plasmodium falciparum Parasite Lines Expressing DC8 and Group A PfEMP1 Bind to Brain, Intestinal, and Kidney Endothelial Cells.

Cytoadhesion of Plasmodium falciparum-infected red blood cells is a virulence determinant associated with microvascular obstruction and organ complications. The gastrointestinal tract is a major site of sequestration in fatal cerebral malaria cases and kidney complications are common in severe malaria, but parasite interactions with these microvascular sites are poorly characterized. To study parasite tropism for different microvascular sites, we investigated binding of parasite lines to primary human microvascular endothelial cells from intestine (HIMEC) and peritubular kidney (HKMEC) sites. Of the three major host receptors for P. falciparum, CD36 had low or negligible expression; endothelial protein C receptor (EPCR) had the broadest constitutive expression; and intercellular adhesion molecule 1 (ICAM-1) was weakly expressed on resting cells and was strongly upregulated by TNF-α on primary endothelial cells from the brain, intestine, and peritubular kidney sites. By studying parasite lines expressing var genes linked to severe malaria, we provide evidence that both the DC8 and Group A EPCR-binding subsets of the P. falciparum erythrocyte membrane protein 1 (PfEMP1) family encodes binding affinity for brain, intestinal, and peritubular kidney endothelial cells, and that DC8 parasite adhesion was partially dependent on EPCR. Collectively, these findings raise the possibility of a brain-gut-kidney binding axis contributing to multi-organ complications in severe malaria.

New Fully Automated Preparation of High Apparent Molar Activity 68Ga-FAPI-46 on a Trasis AiO Platform.

A large number of applications for fibroblast activation protein inhibitors (FAPI)-based PET agents have been evaluated in conditions ranging from cancer to non-malignant diseases such as myocardial infarction. In particular, 68Ga-FAPI-46 was reported to have a high specificity and affinity for FAP-expressing cells, a fast and high accumulation in tumor lesions/injuries together with a fast body clearance when investigated in vivo. Due to the increasing interest in the use of the agent both preclinically and clinically, we developed an automated synthesis for the production of 68Ga-FAPI-46 on a Trasis AiO platform. The new synthetic procedure, which included the processing of the generator eluate using a strong cation exchange resin and a final purification step through an HLB followed by a QMA cartridge, yielded 68Ga-FAPI-46 with high radiochemical purity (>98%) and apparent molar activity (271.1 ± 105.6 MBq/nmol). Additionally, the in vitro and in vivo properties of the product were assessed on glioblastoma cells and mouse model. Although developed for the preparation of 68Ga-FAPI-46 for preclinical use, our method can be adapted for clinical production as a reliable alternative to the manual (i.e., cold kit) or modular systems preparations already described in the literature.

Unprotected peptide macrocyclization and stapling via a fluorine-thiol displacement reaction

We report the discovery of a facile peptide macrocyclization and stapling strategy based on a fluorine thiol displacement reaction (FTDR), which renders a class of peptide analogues with enhanced stability, affinity, cellular uptake, and inhibition of cancer cells. This approach enabled selective modification of the orthogonal fluoroacetamide side chains in unprotected peptides in the presence of intrinsic cysteines. The identified benzenedimethanethiol linker greatly promoted the alpha helicity of a variety of peptide substrates, as corroborated by molecular dynamics simulations. The cellular uptake of benzenedimethanethiol stapled peptides appeared to be universally enhanced compared to the classic ring-closing metathesis (RCM) stapled peptides. Pilot mechanism studies suggested that the uptake of FTDR-stapled peptides may involve multiple endocytosis pathways in a distinct pattern in comparison to peptides stapled by RCM. Consistent with the improved cell permeability, the FTDR-stapled lead Axin and p53 peptide analogues demonstrated enhanced inhibition of cancer cells over the RCM-stapled analogues and the unstapled peptides.

Application of Nanoparticles in the Treatment of Lung Cancer With Emphasis on Receptors.

Lung cancer is one of the malignant tumors that has seen the most rapid growth in terms of morbidity and mortality in recent years, posing the biggest threat to people’s health and lives. In recent years, the nano-drug loading system has made significant progress in the detection, diagnosis, and treatment of lung cancer. Nanomaterials are used to specifically target tumor tissue to minimize therapeutic adverse effects and increase bioavailability. It is achieved primarily through two mechanisms: passive targeting, which entails the use of enhanced penetration and retention (EPR) effect, and active targeting, which entails the loading recognition ligands for tumor marker molecules onto nanomaterials. However, it has been demonstrated that the EPR effect is effective in rodents but not in humans. Taking this into consideration, researchers paid significant attention to the active targeting nano-drug loading system. Additionally, it has been demonstrated to have a higher affinity and specificity for tumor cells. In this review, it describes the development of research into active targeted nano-drug delivery systems for lung cancer treatment from the receptors’ or targets’ perspective. We anticipate that this study will help biomedical researchers use nanoparticles (NPs) to treat lung cancer by providing more and novel drug delivery strategies or solid ligands.

Natural cell based biomimetic cellular transformers for targeted therapy of digestive system cancer.

Digestive system cancer is the most common cause of cancer death in the world. Although cancer treatment options are increasingly diversified, the mortality rate of malignant cancer of the digestive system remains high. Therefore, it is necessary to explore effective cancer treatment methods. Recently, biomimetic nanoparticle delivery systems based on natural cells that organically integrate the low immunogenicity, high biocompatibility, cancer targeting, and controllable, versatile functionality of smart nanocarrier design with natural cells have been expected to break through the bottleneck of tumor targeted therapy. In this review, we focus on the dynamic changes and complex cellular communications that occur in vivo in natural cells based vehicles. Recent studies on the development of advanced targeted drug delivery systems using the dynamic behaviors such as specific surface protein affinity, morphological changes, and phenotypic polarization of natural cells are summarized. In addition to drug delivery mediated by dynamic behavior, functional “delivery” based on the natural cell themselves is also involved. Aiming to make the best use of the functions of cells, providing clues for the development of advanced drug delivery platforms.

Homogeneous antibody-angiopep 2 conjugates for effective brain targeting.

Antibody-based therapy has shown great success in the treatment of many diseases, including cancers. While antibodies and antibody–drug conjugates (ADCs) have also been evaluated for central nervous system (CNS) disorders as well as brain tumors, their therapeutic efficacy can be substantially limited due to low permeability across the blood–brain barrier (BBB). Thus, improving BBB permeability of therapeutic antibodies is critical in establishing this drug class as a reliable clinical option for CNS diseases. Here, we report that, compared with a conventional heterogeneous conjugation, homogeneous conjugation of the synthetic BBB shuttle peptide angiopep-2 (Ang2) to a monoclonal antibody (mAb) provides improved binding affinity for brain microvascular endothelial cells in vitro and accumulation into normal brain tissues in vivo. In a mouse model, we also demonstrate that the homogeneous anti-EGFR mAb–Ang2 conjugate administered intravenously efficiently accumulates in intracranial tumors. These findings suggest that homogeneous conjugation of BBB shuttle peptides such as Ang2 is a promising approach to enhancing the therapeutic efficacy of antibody agents for CNS diseases.

A β-hairpin peptide with pH-controlled affinity for tumor cells.

Considering that the pH in the tumor microenvironment is dysregulated, we designed a β-hairpin peptide (SSRFEWEFESSDPRGDPSSRFEWEFESS). The configuration of the peptide switched from a flexible linear to a rigid loop structure under weakly acidic conditions. The peptide internalized by tumor cells increased significantly under weakly acidic conditions.

Sequentially targeting and intervening mutual Polo-like Kinase 1 on CAFs and tumor cells by dual targeting nano-platform for cholangiocarcinoma treatment.

Rationale: Synergistic treatment strategies for two or more drugs have gradually developed as the main options in clinics for cholangiocarcinoma (CCA) owing to the complicated crosstalk between the tumor and stroma. However, the different synergetic mechanisms pose great challenges to the dosages and order of administration of drugs. Thus, a strategy for exploring and intervening in mutual targets derived from stromal cells and cholangiocarcinoma cells was proposed.Methods: Genes with overexpression patterns in tumors and displaying a significant association with overall survival were identified from RNA-seq data of human CCA patients and CCA mouse models. Western blotting, qRT-PCR, immunofluorescence (IF), colony formation and flow cytometry assays were conducted to determine the biological roles of the key oncogene in cholangiocarcinoma and stromal cells respectively. Additionally, a dual-targeting drug delivery system (AA-HA-ODA) for cancer-associated fibroblasts (CAFs) and tumor cells was constructed to verify the effectiveness of intervening the screened genes in vivo.Results: Polo-like kinase 1 (PLK1) was verified to play vital role in the malignant proliferation of CCA by regulating the cell cycle pathway. PLK1 also decreased stromal production by regulating the CAF phenotype. In addition, a PLK1 inhibitor (Ro3280) loaded dual-targeting drug delivery system (AA-HA-ODA) was prepared and exhibited high affinity for CAFs and cholangiocarcinoma cells. The in vivo distribution pattern and antitumor efficacy of AA-HA-ODA/Ro also verify the effectiveness of inhibiting PLK1 in CCA in vivo.Conclusion: In summary, PLK1 is a mutual target derived from tumor cells and stroma due to its crucial role in the proliferation of tumor cells and stroma regulation in CAFs, which might provide enlightenment for multitarget treatment strategies and guidance for clinical cholangiocarcinoma treatment.

Theranostic Nanoplatform with Sequential SDT and ADV Effects in Response to Well-Programmed LIFU Irradiation for Cervical Cancer.

BackgroundSome patients with cervical cancer have the need to preserve fertility; therefore, a minimally invasive treatment option that can effectively inactivate tumors in these patients is necessary.MethodsIn this paper, we designed and prepared nanoparticles (NPs) carrying IR780 and perfluorohexane (PFH) and characterized their properties. We focused on the promotion of programmed low-intensity focused ultrasound (LIFU) irradiation on the penetration and treatment of cervical cancer. First we used penetration-enhancing LIFU irradiation to promote the penetration of the NPs into 3D multicellular tumor spheroids (MCTSs) and tumors in tumor-bearing nude mice. Then we used re-therapeutic LIFU irradiation to achieve antitumor effects in vitro and in vivo. Photoacoustic (PA) and magnetic resonance (MR) imaging were used to monitor and evaluate the targeting and therapeutic effects of these NPs on tumor tissues.ResultsThe NPs prepared in this paper exhibited high affinity for HeLa cells, and can selectively achieve mitochondrial localization in the cell due to IR780 assistance. The penetration-enhancing LIFU irradiation have the ability to promote the penetration of the NPs into cervical cancer models in vivo and in vitro. Under LIFU irradiation, the cytotoxic reactive oxygen species (ROS) produced by IR780 during the first half of the re-therapeutic LIFU irradiation and the physical acoustic droplet vaporization (ADV) effect after PFH phase transition during the second half of the re-therapeutic LIFU irradiation can achieve synergistic minimally invasive treatment of tumors, which can be visualized and evaluated by PA and MR imaging in vivo.ConclusionWell-programmed LIFU irradiation can promote NP penetration into deep tumor tissue and achieve antitumor effects simultaneously. Linking ROS + ADV effects can induce cell coagulation necrosis and lead to a comprehensive, long-term impact on tumor tissue, providing a conceptual theranostic nanoplatform for cervical cancer.

In vitro and in vivo comparative study of a novel 68Ga-labeled PSMA-targeted inhibitor and 68Ga-PSMA-11

68Ga-radiolabeled small molecules that specifically target prostate-specific membrane antigen (PSMA) have been extensively investigated, and some of these tracers have been used in the diagnosis of prostate cancer via 68Ga-positron emission tomography (68Ga-PET). Nevertheless, current 68Ga-labeled radiotracers show only fair detection rates for metastatic prostate cancer lesions, especially those with lower levels of prostate specific antigen (PSA), which often occurs in the biochemical recurrence of prostate cancer. The goal of this study was to design and synthesize a new PSMA-targeted radiotracer, 68Ga-SC691, with high affinity for prostate cancer cells and excellent pharmacokinetics. To this end, structural optimization was carried out on the bifunctional group, target motif, and linker while the high affinity targeting scaffold remained. To explore its potential in the clinic, a comparative study was further performed in vitro and in vivo between 68Ga-SC691 and 68Ga-PSMA-11, a clinically approved tracer for PSMA-positive prostate cancer. SC691 was radiolabeled to provide 68Ga-SC691 in 99% radiolabeling yield under mild conditions. High uptake and a high internalization ratio into LNCaP cells were observed in in vitro studies. In vivo studies showed that 68Ga-SC691 had favorable biodistribution properties and could specifically accumulate on PSMA-positive LNCaP xenografts visualized by micro-PET/CT. This radiotracer showed excellent PET imaging quality and comparable, if not higher, uptake in LNCaP xenografts than 68Ga-PSMA-11.

Cultural Properties of Cryopreserved Thymic Multipotent Stromal Cells and Fetal Skin and Muscle-Derived Cells

The paper provides a comparison of properties of cryopreserved fetal murine multipotent stromal cells (MSCs) of skin-muscular origin and those derived from adult thymus in culture in vitro. Fetal MSCs showed a 30% higher number of average population doublings within 24 hrs, and 41% lower average population doubling time. It was found that the fetal MSCs of the 4th passage had a 39% higher clonogenic activity than the adult thymus-derived ones. Fetal MSCs and those derived from adult thymus differentiated in osteogenic and adipogenic lineages with equal efficiency in special culture media. Fetal and thymus-derived MSCs were characterized by almost the same high ability of contact interaction with thymocytes, and the fibroblast-lymphocyte rosette (FLR) formation. They were far less active in FLR formation with lymph node cells. This indicated the presence of membrane affinity for immature lymphoid cells in both MSC subpopulations. The results showed the fetal MSCs to be significantly different from the adult thymus-derived MSCs by more active kinetics of growth and clonogenic potential. However, both cell subpopulations had virtually the same ability for linear differentiation and showed high activity during contact with immature lymphoid cells. Linear differentiation and the ability to interact with lymphocytes were found to be quite stable properties of MSCs, but a proliferative activity and in vitro colony formation distinguished significantly in different types of MSCs. This can be taken into account when choosing the cells for therapy, research and results assessment.

Fabrication and Characterization of Graphene Oxide-Coated Plate for Efficient Culture of Stem Cells.

For stem cell applications in regenerative medicine, it is very important to produce high-quality stem cells in large quantities in a short time period. Recently, many studies have shown big potential of graphene oxide as a biocompatible substance to enhance cell growth. We investigated if graphene oxide-coated culture plate can promote production efficiency of stem cells. Three types of graphene oxide were used for this study. They are highly concentrated graphene oxide solution, single-layer graphene oxide solution, and ultra-highly concentrated single-layer graphene oxide solution with different single-layer ratios, and coated on cell culture plates using a spray coating method. Physiochemical and biological properties of graphene oxide-coated surface were analyzed by atomic force microscope (AFM), scanning electron microscope (SEM), cell counting kit, a live/dead assay kit, and confocal imaging. Graphene oxide was evenly coated on cell culture plates with a roughness of 6.4 ~ 38.2nm, as measured by SEM and AFM. Young's Modulus value was up to 115.1GPa, confirming that graphene oxide was strongly glued to the surface. The ex vivo stem cell expansion efficiency was enhanced as bone marrow-derived stem cell doubling time on the graphene oxide decreased compared to the control (no graphene oxide coating), from 64 to 58h, and the growth rate increased up to 145%. We also observed faster attachment and higher affinity of stem cells to the graphene oxide compared to control by confocal microscope. This study demonstrated that graphene oxide dramatically enhanced the ex vivo expansion efficiency of stem cells. Spray coating enabled an ultra-thin coating of graphene oxide on cell culture plates. The results supported that utilization of graphene oxide on culture plates can be a promising mean for mass production of stem cells for commercial applications.

A 3-Dimensional Coculture Model to Visualize and Monitor Interaction Between Pancreatic Cancer and Islet β Cells.

To facilitate exploring a link between pancreatic ductal adenocarcinoma (PDAC) and diabetes mellitus, we constructed a novel 3-dimensional (3D) in vitro coculturing system for studying interactions between PDAC and islet cells. Adopting a 3D rotary cell culture system, we have cocultured several PDAC cell lines and MIN6 islet β cells. The cellular morphology and viability of both cell types were investigated by time-lapse imaging, confocal and scanning electron microscopy, and immunohistochemistry. The developed coculture method enabled the formation of 3D PDAC and β-cell spheroids (pseudo islets). We showed that surface morphology and growth of cultured cells mimicked their in vivo appearance. In addition, the coculture demonstrated the affinity of the PDAC cells to grow around and invade the pseudo islets. Using rotary cell culture system, we have established a simple in vitro 3D pancreatic model. It is a flexible culture system that can easily be expanded with the addition of various stromal/neural components to further mimic in vivo conditions, thus enabling holistic investigation of the endocrine and exocrine pancreas.

A tailored extracellular matrix (ECM) - Mimetic coating for cardiovascular stents by stepwise assembly of hyaluronic acid and recombinant human type III collagen

Collagen, a central component of the extracellular matrix (ECM), has been widely applied in tissue engineering, among others, for wound healing or bone and nerve regeneration. However, the inherent thrombogenic properties of collagen hinder the application in blood-contacting devices. Herein, a brand-new recombinant human type III collagen (hCOLIII) was explored that does not present binding sites for platelets while retaining the affinity for endothelial cells. The hCOLIII together with hyaluronic acid (HA) were deposited on the substrates via layer-by-layer assembly to form an ECM-mimetic multilayer coating. In vitro platelet adhesion and ex vivo blood circulation tests demonstrated prominent thromboprotective properties for the hCOLIII-based ECM-mimetic coating. In addition, the coating effectively guided the vascular cell fate by supporting the proliferation of endothelial cells and inhibiting the proliferation of smooth muscle cells by differentiating them to a more contractile phenotype. A polylactic acid (PLA) stent coated with hCOLIII-based ECM-mimetic coating was implanted in the abdominal aorta of rabbits to investigate the healing of the neointima. The enhanced endothelialization, suppressed inflammatory response, inhibition of excessive neointimal hyperplasia, and the superior thromboprotection strongly indicated the prospect of the hCOLIII-based ECM-mimetic coating as a tailored blood-contacting material for cardiovascular stents.