Novel egg white–based 3-D cell culture system

Preliminary study on comparison of egg extraction methods for development of fetal bovine serum substitutes in cultured meat

Fetal bovine serum (FBS) substitution remains one of the challenges to the realization of cultured meat production in the marketplace. In this study, three methods were developed to extract a substitute for FBS using egg white extract (EWE): using 25 mM CaCl2/2.5 % ammonium sulfate/citric acid (A); ethyl alcohol (B); and 5 % ammonium sulfate/citric acid (C). B EWE can effectively replace up to 50 % of FBS in growth media (10 % of the total). Ovalbumin in the extracts can promote cell proliferation, and components along the 12 kDa protein band have the potential to inhibit cell proliferation. Chick primary muscle cells applied with B EWE, an edible material that improved the cost and time efficiency of cultured meat production, effectively proliferated/differentiated. Therefore, EWE extracted using ethyl alcohol may be used as an FBS substitute to reduce animal sacrifices and should be considered a viable alternative to FBS for cultured meat.

Silk Fibroin Improves the Biological Properties of Egg White-Based Bioink for the Bioprinting of Tissue Engineering Materials

Egg white (EW) is a common nutritious food with excellent heat gelation and biocompatibility, but its application in biomaterials is considerably limited. Silk fibroin (SF) is a protein-based fiber with both excellent mechanical properties and biocompatibility, and its application in biomaterials has attracted much attention. Here, the EW/SF composite scaffold was first synthesized with GMA-modified EW/SF composite bioink (G-EW/SF). When homogenized EW and SF were individually grafted with glycidyl methacrylate (GMA), the grafted EW (G-EW) and SF (G-SF) were mixed in different proportions and then added to I2959. The resulting G-EW/SF composite bioink could be bioprinted into various EW/SF composite scaffolds. Among them, the compressive modulus of EW/SF (50%) composite scaffolds incorporating 50% G-SF was significantly improved. It had a three-dimensional (3D) polypore structure with an average pore size of 61 μm and was mainly composed of β-sheet structures. Compared with the EW scaffold alone, the thermal decomposition temperature of the EW/SF scaffold was 10 °C higher, and the residual rate after 9 days of enzymatic hydrolysis had increased by about 18%. The scaffold prolonged the sustained release of insulin and promoted the adhesion, growth, and proliferation of the L-929 cells. Therefore, the EW/SF composite scaffolds with good cell proliferation ability and certain mechanical properties can be used in different applications including cells, drugs, and tissues. These results provide new prospects for the application of the EW protein to medical tissue engineering materials.

Mending a broken heart by biomimetic 3D printed natural biomaterial-based cardiac patches: a review

Myocardial infarction is one of the major causes of mortality as well as morbidity around the world. Currently available treatment options face a number of drawbacks, hence cardiac tissue engineering, which aims to bioengineer functional cardiac tissue, for application in tissue repair, patient specific drug screening and disease modeling, is being explored as a viable alternative. To achieve this, an appropriate combination of cells, biomimetic scaffolds mimicking the structure and function of the native tissue, and signals, is necessary. Among scaffold fabrication techniques, three-dimensional printing, which is an additive manufacturing technique that enables to translate computer-aided designs into 3D objects, has emerged as a promising technique to develop cardiac patches with a highly defined architecture. As a further step toward the replication of complex tissues, such as cardiac tissue, more recently 3D bioprinting has emerged as a cutting-edge technology to print not only biomaterials, but also multiple cell types simultaneously. In terms of bioinks, biomaterials isolated from natural sources are advantageous, as they can provide exceptional biocompatibility and bioactivity, thus promoting desired cell responses. An ideal biomimetic cardiac patch should incorporate additional functional properties, which can be achieved by means of appropriate functionalization strategies. These are essential to replicate the native tissue, such as the release of biochemical signals, immunomodulatory properties, conductivity, enhanced vascularization and shape memory effects. The aim of the review is to present an overview of the current state of the art regarding the development of biomimetic 3D printed natural biomaterial-based cardiac patches, describing the 3D printing fabrication methods, the natural-biomaterial based bioinks, the functionalization strategies, as well as the in vitro and in vivo applications.

Hydrocolloids of Egg White and Gelatin as a Platform for Hydrogel-Based Tissue Engineering

Innovative materials are needed to produce scaffolds for various tissue engineering and regenerative medicine (TERM) applications, including tissue models. Materials derived from natural sources that offer low production costs, easy availability, and high bioactivity are highly preferred. Chicken egg white (EW) is an overlooked protein-based material. Whilst its combination with the biopolymer gelatin has been investigated in the food technology industry, mixed hydrocolloids of EW and gelatin have not been reported in TERM. This paper investigates these hydrocolloids as a suitable platform for hydrogel-based tissue engineering, including 2D coating films, miniaturized 3D hydrogels in microfluidic devices, and 3D hydrogel scaffolds. Rheological assessment of the hydrocolloid solutions suggested that temperature and EW concentration can be used to fine-tune the viscosity of the ensuing gels. Fabricated thin 2D hydrocolloid films presented globular nano-topography and in vitro cell work showed that the mixed hydrocolloids had increased cell growth compared with EW films. Results showed that hydrocolloids of EW and gelatin can be used for creating a 3D hydrogel environment for cell studies inside microfluidic devices. Finally, 3D hydrogel scaffolds were fabricated by sequential temperature-dependent gelation followed by chemical cross-linking of the polymeric network of the hydrogel for added mechanical strength and stability. These 3D hydrogel scaffolds displayed pores, lamellae, globular nano-topography, tunable mechanical properties, high affinity for water, and cell proliferation and penetration properties. In conclusion, the large range of properties and characteristics of these materials provide a strong potential for a large variety of TERM applications, including cancer models, organoid growth, compatibility with bioprinting, or implantable devices.

Egg white improves the biological properties of an alginate-methylcellulose bioink for 3D bioprinting of volumetric bone constructs

Three-dimensional microextrusion bioprinting has attracted great interest for fabrication of hierarchically structured, functional tissue substitutes with spatially defined cell distribution. Despite considerable progress, several significant limitations remain such as a lack of suitable bioinks which combine favorable cell response with high shape fidelity. Therefore, in this work a novel bioink of alginate-methylcellulose (AlgMC) blend functionalized with egg white (EW) was developed with the aim of solving this limitation. In this regard, a stepwise strategy was proposed to improve and examine the cell response in low-viscosity alginate inks (3%, w/v) with different EW concentrations, and in high-viscosity inks after gradual methylcellulose addition for enhancing printability. The rheological properties and printability of these cell-responsive bioinks were characterized to obtain an optimized formulation eliciting balanced physicochemical and biological properties for fabrication of volumetric scaffolds. The bioprinted AlgMC + EW constructs exhibited excellent shape fidelity while encapsulated human mesenchymal stem cells showed high post-printing viability as well as adhesion and spreading within the matrix. In a proof-of-concept experiment, the impact of these EW-mediated effects on osteogenesis of bioprinted primary human pre-osteoblasts (hOB) was evaluated. Results confirmed a high viability of hOB (93.7 ± 0.15%) post-fabrication in an EW-supported AlgMC bioink allowing cell adhesion, proliferation and migration. EW even promoted the expression of osteogenic genes, coding for bone sialoprotein (integrin binding sialoprotein/bone sialoprotein precursor (IBSP)) and osteocalcin (BGLAP) on mRNA level. To demonstrate the suitability of the novel ink for future fabrication of multi-zonal bone substitutes, AlgMC + EW was successfully co-printed together with a pasty calcium phosphate bone cement biomaterial ink to achieve a partly mineralized 3D volumetric environment with good cell viability and spreading. Along with the EW-mediated positive effects within bioprinted AlgMC-based scaffolds, this highlighted the promising potential of this novel ink for biofabrication of bone tissue substitutes in clinically relevant dimensions.

Fabrication and characterization of three-dimensional polycaprolactone/sodium alginate and egg whites and eggshells hybrid scaffold in bone tissue engineering

The aim of this study was to fabricate three-dimensional bone scaffolds using polycaprolactone and egg shell powder. The scaffolds were coated with sodium alginate/egg white. SEM was used to investigate egg shell particles on the surface of each string of scaffolds. The presence of calcium carbonate in the scaffold structure was confirmed by microstructural analyses employing XRD. Egg shell-related functional groups were discovered using FTIR investigations. Bone cells were used to conduct biocompatibility tests on scaffolds (MG-63). Finally, scaffolds with the highest proportion of egg whites and eggshells have the best cell survival rate. It may be concluded that the PCL/7% Esh/15% Ew scaffold is a good option for application in bone tissue engineering.

COMPARİSON OF EGG WHİTE AND Ε-POLYCAPROLACTONE FOR THREE-DİMENSİONAL CELL CULTURE

It is increasingly becoming important to develop three-dimensional (3-D) cell culture systems due to their numerous advantages over traditional monolayer culture. The aim of this study is to investigate the interaction of adipose derived stem cells (ADSCs) with scaffolds composed of ε-polycaprolactone (ε-PCL) and egg white. In our study; ε-PCL and egg white scaffolds were fabricated from their monomers under the catalysis of tin octoate and by polymerization by heat respectively. Characterization of PCL was carried out with Gel permeability chromatography (GPC), Fourier Transform Infrared Spectrophotometry (FTIR), Proton Nuclear Magnetic Resonance (H-NMR), Differential Scan Calorimetry (DSC) and Scanning Electron Microscopy (SEM). CM-DiI labeled ADSCs were cultured for 12 days on egg white and ε-PCL scaffolds. Cell viability was performed using MTT and nitric oxide level was evaluated for toxicity. Results showed that the number of ADSCs on egg white scaffold increased periodically throughout 12 days compared with the other groups. Although the number of ADSCs on ε-PCL scaffold increased until the 6th day of the culture, the cell number began to decrease after day 6.. These results were associated with the decomposition of PCL scaffolds that occurs through catabolic reactions. This causes the release of lactic acid which makes toxic effect on the cells. Thus, these results showed that egg white scaffold increases and protects cell adhesion and cell viability more than ε-Polycaprolactone scaffold, thus it can be used as a scaffold in tissue engineering studies that involve stem cells.

Egg White Alginate as a Novel Scaffold Biomaterial for 3D Salivary Cell Culturing

Saliva production by salivary glands play a crucial role in oral health. The loss of salivary gland function could lead to xerostomia, a condition also known as dry mouth. Significant reduction in saliva production could lead to further complications such as difficulty in speech, mastication, and increased susceptibility to dental caries and oral infections and diseases. While some palliative treatments are available for xerostomia, there are no curative treatments to date. This study explores the use of Egg White Alginate (EWA), as an alternative scaffold to Matrigel^® for culturing 3D salivary gland cells. A protocol for an optimized EWA was established by comparing cell viability using 1%, 2%, and 3% alginate solution. The normal salivary simian virus 40-immortalized acinar cell (NS-SV-AC) and the submandibular gland-human-1 (SMG-hu-1) cell lines were also used to compare the spheroid formation and cell viability properties of both scaffold biomaterials; cell viability was observed over 10 days using a Live–Dead Cell Assay. Cell viability and spheroid size in 2% EWA was significantly greater than 1% and 3%. It is evident that EWA can support salivary cell survivability as well as form larger spheroids when compared to cells grown in Matrigel^®. However, further investigations are necessary as it is unclear if cultured cells were proliferating or aggregating.

Bioprinting and In Vitro Characterization of an Eggwhite-Based Cell-Laden Patch for Endothelialized Tissue Engineering Applications

Three-dimensional (3D) bioprinting is an emerging fabrication technique to create 3D constructs with living cells. Notably, bioprinting bioinks are limited due to the mechanical weakness of natural biomaterials and the low bioactivity of synthetic peers. This paper presents the development of a natural bioink from chicken eggwhite and sodium alginate for bioprinting cell-laden patches to be used in endothelialized tissue engineering applications. Eggwhite was utilized for enhanced biological properties, while sodium alginate was used to improve bioink printability. The rheological properties of bioinks with varying amounts of sodium alginate were examined with the results illustrating that 2.0-3.0% (w/v) sodium alginate was suitable for printing patch constructs. The printed patches were then characterized mechanically and biologically, and the results showed that the printed patches exhibited elastic moduli close to that of natural heart tissue (20-27 kPa) and more than 94% of the vascular endothelial cells survived in the examination period of one week post 3D bioprinting. Our research also illustrated the printed patches appropriate water uptake ability (>1800%).

Edible Materials in Tissue Regeneration

Edible materials have attracted increasing attention because of their excellent properties including availability, biocompatibility, biological activity, and biodegradability. Natural polysaccharides, phenolic compounds, and proteins are widely used in tissue regeneration. To better characterize their healing effect, this review article describes the applications of edible materials in tissue regeneration including wound healing and bone tissue regeneration. As an introduction to the topic, their sources and main bioactive properties are discussed. Then, the mechanism by which they facilitate wound healing based on their hemostasis, antibacterial, anti-inflammatory, and antioxidant properties is systematically investigated. Moreover, a more comprehensive discussion is presented on the approaches by which edible materials can be used as scaffolds or agents for the provision of the components of natural bones for regulating the level of osteogenesis-related cytokines to enhance bone repair. Finally, the prospects of edible materials for tissue regeneration are discussed.

Recent Advances in 3D Printing with Protein-Based Inks

Three-dimensional (3D) printing is a transformative manufacturing strategy, allowing rapid prototyping, customization, and flexible manipulation of structure-property relationships. Proteins are particularly appealing to formulate inks for 3D printing as they serve as essential structural components of living systems, provide a support presence in and around cells and for tissue functions, and also provide the basis for many essential ex vivo secreted structures in nature. Protein-based inks are beneficial in vivo due to their mechanics, chemical and physical match to the specific tissue, and full degradability, while also to promoting implant-host integration and serving as an interface between technology and biology. Exploiting the biological, chemical, and physical features of protein-based inks can provide key opportunities to meet the needs of tissue engineering and regenerative medicine. Despite these benefits, protein-based inks impose nontrivial challenges to 3D printing such as concentration and rheological features and reconstitution of the structural hierarchy observed in nature that is a source of the robust mechanics and functions of these materials. This review introduces photo-crosslinking mechanisms and rheological principles that underpins a variety of 3D printing techniques. The review also highlights recent advances in the design, development, and biomedical utility of monolithic and composite inks from a range of proteins, including collagen, silk, fibrinogen, and others. One particular focus throughout the review is to introduce unique material characteristics of proteins, including amino acid sequences, molecular assembly, and secondary conformations, which are useful for designing printing inks and for controlling the printed structures. Future perspectives of 3D printing with protein-based inks are also provided to support the promising spectrum of biomedical research accessible to these materials.

The Optimization of a Novel Hydrogel-Egg White-Alginate for 2.5D Tissue Engineering of Salivary Spheroid-Like Structure

Hydrogels have been used for a variety of biomedical applications; in tissue engineering, they are commonly used as scaffolds to cultivate cells in a three-dimensional (3D) environment allowing the formation of organoids or cellular spheroids. Egg white-alginate (EWA) is a novel hydrogel which combines the advantages of both egg white and alginate; the egg white material provides extracellular matrix (ECM)-like proteins that can mimic the ECM microenvironment, while alginate can be tuned mechanically through its ionic crosslinking property to modify the scaffold's porosity, strength, and stiffness. In this study, a frozen calcium chloride (CaCl2) disk technique to homogenously crosslink alginate and egg white hydrogel is presented for 2.5D culture of human salivary cells. Different EWA formulations were prepared and biologically evaluated as a spheroid-like structure platform. Although all five EWA hydrogels showed biocompatibility, the EWA with 1.5% alginate presented the highest cell viability, while EWA with 3% alginate promoted the formation of larger size salivary spheroid-like structures. Our EWA hydrogel has the potential to be an alternative 3D culture scaffold that can be used for studies on drug-screening, cell migration, or as an in vitro disease model. In addition, EWA can be used as a potential source for cell transplantation (i.e., using this platform as an ex vivo environment for cell expansion). The low cost of producing EWA is an added advantage.

An insight on egg white: From most common functional food to biomaterial application

Natural egg white tis widely used as an ingredient in nutritional foods and for food processing. Due to its characteristic foaming, emulsification, adhesion, and gelation, and its heat setting, biocompatibility, and low cost, research into the application and development of egg white in biomaterials, especially medical biomaterials, have been receiving attention. The composition and characteristics of egg white protein, and the physical mixing and chemically cross-linking of egg white with other materials used to make degradable packaging films, bioceramics, bioplastics, biomimetic films, hydrogels, 3D scaffolds, bone regeneration, biopatterning, biosensors, and so forth, are reviewed in detail in this report. The novel egg white-based biomaterials in various forms and applications could be constructed mostly through physical treatments such as ultrasonic wave, ultraviolet, laser and other radiation or high-temperature calcination. Furthermore, the application and prospects for the use of egg white in biomaterials is also discussed.

3D Cell Culture of Human Salivary Glands Using Nature-Inspired Functional Biomaterials: The Egg Yolk Plasma and Egg White

The egg yolk plasma (EYP)-a translucent fraction of the egg yolk (EY) obtained by centrifugation-was tested as a developmentally encouraging, cost-effective, biomaterial for salivary gland (SG) tissue engineering. To find optimal incubating conditions for both the human NS-SV-AC SG acinar cell line and SG fibroblasts, cells were stained with Live/Dead®. The cellular contents of 96-well plates were analyzed by high content screening image analysis. Characteristically, the EYP biomaterial had lipid and protein content resembling the EY. On its own, the EYP was non-conducive to cell survival. EYP's pH of 6 mainly contributed to cell death. This was demonstrated by titrating EYP's pH with different concentrations of either commercial cell culture media, NaOH, or egg white (EW). These additives improved SG mesenchymal and epithelial cell survival. The best combinations were EYP diluted with (1) 70% commercial medium, (2) 0.02 M NaOH, or (3) 50% EW. Importantly, commercial medium-free growth was obtained with EYP + NaOH or EYP + EW. Furthermore, 3D cultures were obtained as a result of EW's gelatinous properties. Here, the isolation, characterization, and optimization of three EYP-based biomaterial combinations are shown; two were free of commercial medium or supplements and supported both SG cells' survival.

Characterization of Hen's Egg White To Use It as a Novel Platform To Culture Three-Dimensional Multicellular Tumor Spheroids

We are standardizing protocols to develop egg white (EW) as a cost-effective platform for culture of three-dimensional (3-D) multicellular tumor spheroids for application in understanding tumor microenvironments and drug screening. In this article, we describe several physical and physiological characteristics of EW to use it as 3-D cell culture platform. Field emission scanning electron microscopy revealed the presence of different microstructures. Hydrodynamic size distribution data indicated nano- and micron-sized particles. Rheological measurements revealed the viscosity and viscoelastic behavior appropriate for maintaining cell viability and supporting 3-D cell growth under high-sheer conditions. It was found that thereis no autofluorescence, a requirement for imparting transparency and for microscopic observations of the spheroids. The EW facilitated the development of 3-D tumor spheroids, with an emphasis of difference in cell proliferation and intercellular cytoskeletal organization between two-dimensional and 3-D spheroid cultures. Put together, EW proves to be a cost-affordable and simple platform for 3-D culture of tumor spheroids.

The hedgehog pathway regulates cancer stem cells in serous adenocarcinoma of the ovary

PURPOSE

Signaling by cancer stem cells (CSCs) is known to occur at least in part through conserved developmental pathways. Here, the role of one of these pathways, i.e., the hedgehog pathway, was evaluated in high-grade serous ovarian carcinoma (HGSOC).

METHODS AND RESULTS

We found that in HGSOC, hedgehog inhibitors (HHIs) GANT61, LDE225 and GDC0449 reduced or inhibited the formation of spheroids enriched in CSCs. Primary malignant cells (PMCs) in ascites from HGSOC patients cultured in the presence of HHIs showed significant reduction in CSCs. Sonic hedgehog (SHH) significantly increased the expression of ALDH1A1, which was inhibited by GANT61. In the presence of a SHH neutralizing antibody (5E1), a significant reduction in the number of spheroids was observed in HGSOC-derived cell lines. Further, the motility, migration and clonogenic growth of the cells were significantly reduced by HHIs. In the presence of GANT61, a reduction of cells from PMCs in the G0 phase of the cell cycle was observed. The magnitude of difference in expression of Gli1 in tumors from the same HGSOC patients at presentation and at interval debulking surgery was greater in patients who had a recurrence on follow up. GANT61 also significantly inhibited the growth of CSCs in nude mice. Finally, RNA sequencing of HGSOC cells treated with GANT61 showed a significantly reduced expression of CSC markers.

CONCLUSIONS

Our results indicate that the hedgehog pathway plays an important role in maintaining the integrity of CSCs in HGSOC and could be a potential therapeutic target.

3D Cultures of Salivary Gland Cells in Native or Gelled Egg Yolk Plasma, Combined with Egg White and 3D-Printing of Gelled Egg Yolk Plasma

For salivary gland (SG) tissue engineering, we cultured acinar NS-SV-AC cell line or primary SG fibroblasts for 14 days in avian egg yolk plasma (EYP). Media or egg white (EW) supplemented the cultures as they grew in 3D-Cryo histology well inserts. In the second half of this manuscript, we measured EYP’s freeze-thaw gelation and freeze-thaw induced gelled EYP (_GEYP), and designed and tested further _GEYP tissue engineering applications. With a 3D-Cryo well insert, we tested _GEYP as a structural support for 3D cell culture or as a bio-ink for 3D-Bioprinting fluorescent cells. In non-printed EYP + EW or _GEYP + EW cultures, sagittal sections of the cultures showed cells remaining above the well’s base. Ki-67 expression was lacking for fibroblasts, contrasting NS-SV-AC’s constant expression. Rheological viscoelastic measurements of _GEYP at 37 °C on seven different freezing periods showed constant increase from 0 in mean storage and loss moduli, to 320 Pa and 120 Pa, respectively, after 30 days. We successfully 3D-printed _GEYP with controlled geometries. We manually extruded _GEYP bio-ink with fluorescence cells into a 3D-Cryo well insert and showed cell positioning. The 3D-Cryo well inserts reveal information on cells in EYP and we demonstrated _GEYP cell culture and 3D-printing applications.

Analyzing the Type II Transmembrane Serine Protease Hepsin-Dependent Basement Membrane Remodeling in 3D Cell Culture

Breakdown of the basement membrane is a key step that precedes tumor invasion, and accumulating evidence suggests a key role for the type II transmembrane proteases (TTSPs) in that process. Overexpression of a TTSP hepsin characterizes many solid cancers, including prostate, breast, and ovarian cancer, and in experimental tumor models, the elevated proteolytic activity of hepsin simultaneously activates several growth factors and cleaves basement membrane protein laminin-332, which is an essential component of the cell-basement membrane junction hemidesmosome. These hepsin-dependent molecular events associate with dramatic loss of basement membrane integrity in mouse tumor models and in three-dimensional (3D) epithelial culture. In particular, the 3D culture systems offer unprecedented possibilities to clarify the mechanistic basis of destructive interactions between out-of-control serine protease activity and the basement membrane structure. Here, we describe how to establish 3D mammary epithelial culture in an exogenous basement membrane-free egg white matrix and provide a protocol for quantitative analysis of the impact of hepsin on laminin-332 and its hemidesmosomal receptor α6-integrin by means of confocal microscopy imaging. These protocols were established to facilitate studies aiming to decipher the exact role of oncogenic proteases in tumor invasion processes and to identify novel therapeutic agents able to intervene these cancer critical processes.

On the development of multifunctional luminescent supramolecular hydrogel of gold and egg white

Highly stable, luminescent, and printable/paintable supramolecular egg white hydrogel-based surface enhanced Raman scattering (SERS) matrix is created by an in situ synthesis of gold clusters inside a luminescent egg white hydrogel (Au-Gel). The synthesis of stable luminescent egg-white-based hydrogel, where the hydrogel can act as a three dimensional (3D) matrix, using a simple cross-linking chemistry, has promising application in the biomedical field including in 3D cell culturing. Furthermore, this functional hydrogel is demonstrated for micromolar-level detection of Rhodamine 6G using the SERS technique, where Au-Gel is painted over a flexible cellulose pad.

Bifunctional Luminomagnetic Rare-Earth Nanorods for High-Contrast Bioimaging Nanoprobes

Nanoparticles exhibiting both magnetic and luminescent properties are need of the hour for many biological applications. A single compound exhibiting this combination of properties is uncommon. Herein, we report a strategy to synthesize a bifunctional luminomagnetic Gd2-xEuxO3 (x = 0.05 to 0.5) nanorod, with a diameter of ~20 nm and length in ~0.6 μm, using hydrothermal method. Gd2O3:Eu(3+) nanorods have been characterized by studying its structural, optical and magnetic properties. The advantage offered by photoluminescent imaging with Gd2O3:Eu(3+) nanorods is that this ultrafine nanorod material exhibits hypersensitive intense red emission (610 nm) with good brightness (quantum yield more than 90%), which is an essential parameter for high-contrast bioimaging, especially for overcoming auto fluorescent background. The utility of luminomagnetic nanorods for biological applications in high-contrast cell imaging capability and cell toxicity to image two human breast cancer cell lines T47D and MDA-MB-231 are also evaluated. Additionally, to understand the significance of shape of the nanostructure, the photoluminescence and paramagnetic characteristic of Gd2O3:Eu(3+) nanorods were compared with the spherical nanoparticles of Gd2O3:Eu(3+).

Getting the whole picture: High content screening using three-dimensional cellular model systems and whole animal assays

Phenotypic or High Content Screening (HCS) is becoming more widely used for primary screening campaigns in drug discovery. Currently the vast majority of HCS campaigns are using cell lines grown in well-established monolayer cultures (2D tissue culture). There is widespread recognition that the more biologically relevant 3D tissue culture technologies such as spheroids and organoids and even whole animal assays will eventually be run as primary HCS. Upgrading the IT infrastructure to cope with the increase in data volumes requires investments in hardware (and software) and this will be manageable. However, the main bottleneck for the effective adoption and use of 3D tissue culture and whole animal assays in HCS is anticipated to be the development of software for the analysis of 3D images. In this review we summarize the current state of the available software and how they may be applied to analyzing 3D images obtained from a HCS campaign. © 2016 International Society for Advancement of Cytometry.

The effects of macroporosity and stiffness of poly[(methyl vinyl ether)-alt-(maleic acid)] cross-linked egg white simulations of an aged extracellular matrix on the proliferation of ovarian cancer cells

The effects of macroporosity and stiffness of P(MVE-alt-MA) cross-linked EW simulations of an aged ECM on the proliferation of cancer cells.

Facile fabrication of egg white macroporous sponges for tissue regeneration

The availability of 3D sponges combining proper biochemical, biophysical, and biomechanical properties with enhanced capacity of in vivo engraftment and vascularization is crucial in regenerative medicine. A simple process is developed to generate macroporous scaffolds with a well-defined architecture of interconnected pores from chicken egg white (EW), a material with protein- and growth factor-binding features which has not yet been employed in regenerative medicine. The physicomechanical properties and degradation rates of the scaffold are finely tuned by using varying concentrations of the cross-linker, 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride, without alteration of the biochemical traits. In vitro, EW scaffolds supported active metabolism, proliferation, and migration of human dermal fibroblasts, thereby generating uniform cellular constructs. In vivo, subcutaneous implantation in mice reveals negligible immune reaction and efficient cell and tissue ingrowth. Angiogenesis into EW scaffolds is enhanced as compared to standard collagen type I sponges used as reference material, likely due to significantly higher adsorption of the proangiogenic factor vascular endothelial growth factor. In summary, a material is presented derived by facile processing of a highly abundant natural product. Due to the efficient subcutaneous engraftment capacity, the sponges can find utilization for soft tissue regeneration.

HPV16 Down-Regulates the Insulin-Like Growth Factor Binding Protein 2 to Promote Epithelial Invasion in Organotypic Cultures

Cervical cancer is a multi-stage disease caused by human papillomaviruses (HPV) infection of cervical epithelial cells, but the mechanisms regulating disease progression are not clearly defined. Using 3-dimensional organotypic cultures, we demonstrate that HPV16 E6 and E7 proteins alter the secretome of primary human keratinocytes resulting in local epithelial invasion. Mechanistically, absence of the IGF-binding protein 2 (IGFBP2) caused increases in IGFI/II signalling and through crosstalk with KGF/FGFR2b/AKT, cell invasion. Repression of IGFBP2 is mediated by histone deacetylation at the IGFBP2 promoter and was reversed by treatment with histone deacetylase (HDAC) inhibitors. Our in vitro findings were confirmed in 50 invasive cancers and 79 cervical intra-epithelial neoplastic lesions caused by HPV16 infection, where IGFBP2 levels were reduced with increasing disease severity. In summary, the loss of IGFBP2 is associated with progression of premalignant disease, and sensitises cells to pro-invasive IGF signalling, and together with stromal derived factors promotes epithelial invasion.

In vitro 3D angiogenesis assay in egg white matrix: comparison to Matrigel, compatibility to various species, and suitability for drug testing

In vitro angiogenesis assays are commonly used to assess pro- or anti-angiogenic drug properties. Extracellular matrix (ECM) substitutes such as Matrigel and collagen gel became very popular in in vitro 3D angiogenesis assays as they enable tubule formation by endothelial cells from culture or aortic rings. However, these assays are usually used with a single cell type, lacking the complex cellular interactions occurring during angiogenesis. Here, we report a novel angiogenesis assay using egg white as ECM substitute. We found that, similar to Matrigel, egg white elicited prevascular network formation by endothelial and/or smooth muscle cell coculture. This matrix was suitable for various cells from human, mouse, and rat origin. It is compatible with aortic ring assay and also enables vascular and tumor cell coculture. Through simple labeling (DAPI, Hoechst 33258), cell location and resulting prevascular network formation can easily be quantified. Cell transfection with green fluorescent protein improved whole cell visualization and 3D structure characterization. Finally, egg-based assay dedicated to angiogenesis studies represents a reliable and cost-effective way to produce and analyze data regarding drug effects on vascular cells.

Highly luminescent-paramagnetic nanophosphor probes for in vitro high-contrast imaging of human breast cancer cells

Highly luminescent-paramagnetic nanophosphors have a seminal role in biotechnology and biomedical research due to their potential applications in biolabeling, bioimaging, and drug delivery. Herein, the synthesis of high-quality, ultrafine, europium-doped yttrium oxide nanophosphors (Y(1.9)O(3):Eu(0.1)(3+)) using a modified sol-gel technique is reported and in vitro fluorescence imaging studies are demonstrated in human breast cancer cells. These highly luminescent nanophosphors with an average particle size of ≈6 nm provide high-contrast optical imaging and decreased light scattering. In vitro cellular uptake is shown by fluorescence microscopy, which visualizes the characteristic intense hypersensitive red emission of Eu(3+) peaking at 610 nm ((5)D(0)-(7)F(2)) upon 246 nm UV light excitation. No apparent cytotoxicity is observed. Subsequently, time-resolved emission spectroscopy and SQUID magnetometry measurements demonstrate a photoluminescence decay time in milliseconds and paramagnetic behavior, which assure applications of the nanophosphors in biomedical studies.

High-efficiency transfection of suspension cell lines

Transfection of suspension cells has proven to be very difficult using conventional methods. Here, we present a simple and time-saving new transfection protocol wherein cell culture plates coated with chicken egg white are seeded with suspension cells prior to transfection. Our results demonstrate that coupling egg white coatings with commercially available transfection reagents leads to high transfection efficiency with suspension cell lines including canine mastocytoma C2 and the human myeloid cell line HL-60. This new approach, which should prove applicable to a wide range of cell lines, solves a crucial problem for researchers working with suspension cells.

Fingolimod potentiates the effects of sunitinib malate in a rat breast cancer model

Most of the antiangiogenic strategies used in oncology principally target endothelial cells through the vascular endothelial growth factor (VEGF) pathway. Multiple kinase inhibitors can secondarily reduce mural cell stabilization of the vessels by blocking platelet-derived growth factor receptor (PDGFR) activity. However, sphingosine-1-phosphate (S1P), which is also implicated in mural cell recruitment, has yet to be targeted in clinical practice. We therefore investigated the potential of a simultaneous blockade of the PDGF and S1P pathways on the chemotactic responses of vascular smooth muscle cells (VSMCs) and the resulting effects of this blockade on breast tumor growth. Due to crosstalk between the S1P and PDGF pathways, we used AG1296 and/or VPC-23019 to inhibit PDGFR-β and S1PR1/S1PR3 receptors, respectively. We showed that S1PR1 and S1PR3 are the principal receptors that mediate the S1P chemotactic signal on rat VSMCs and that they act synergistically with PDGFR-β during PDGF-B signaling. We also showed that simultaneous blockade of the PDGFR-β and S1PR1/S1PR3 signals had a synergistic effect, decreasing VSMC migration velocity toward endothelial cell and breast carcinoma cell-secreted cytokines by 65-90%. This blockade also strongly decreased the ability of VSMCs to form a three-dimensional cell network. Similar results were obtained with the combination of sunitinib malate (a VEGFR/PDGFR kinase inhibitor) and fingolimod (an S1P analog). Sunitinib malate is a clinically approved cancer treatment, whereas fingolimod is currently indicated only for treatment of multiple sclerosis. Orally administered, the combination of these drugs greatly decreased rat breast tumor growth in a syngeneic cancer model (Walker 256). This bi-therapy did not exert cumulative toxicity and histological analysis of the tumors revealed normalization of the tumor vasculature. The simultaneous blockade of these signaling pathways with sunitinib malate and fingolimod may provide an effective means of reducing tumor angiogenesis, and may improve the delivery of other chemotherapies.

Dual regulation of breast tubulogenesis using extracellular matrix composition and stromal cells

Epithelial-mesenchymal interactions during embryogenesis are critical in defining the phenotype of tissues and organs. The initial elongation of the mammary bud represents a central morphological event requiring extensive epithelial-mesenchymal crosstalk. The precise mechanism orchestrating this outgrowth is still unknown and mostly animal models have been relied upon to explore this process. Highly tunable three-dimensional (3D) culture models are a complementary approach to address the question of phenotypic determination. Here, we used a 3D in vitro culture to study the roles of stromal cells and extracellular matrix components during mammary tubulogenesis. Fibroblasts, adipocytes, and type I collagen actively participated in this process, whereas reconstituted basement membrane inhibited tubulogenesis by affecting collagen organization. We conclude that biochemical and biomechanical signals mediate the interaction between cells and matrix components and are necessary to induce tubulogenesis in vitro.