Double-responsive hyaluronic acid-based prodrugs for efficient tumour targeting.

Hyaluronic acid (HA)-based prodrugs bearing double-responsive (acid pH or oxidation) boronates of catechol-containing drugs were used to treat xenografted human prostate tumours (LNCaP) in SCID mice. The HA prodrugs accumulated significantly only in tumours (impressively, up to 40% of the injected dose after 24 h) and in liver, with negligible - actually anti-inflammatory - consequences in the latter. A quercetin-HA prodrug significantly slowed down tumour growth, in a dose-dependent fashion and with a much higher efficacy (up to 4 times) than equivalent doses of free quercetin. In short, boronated HA appears to be a very promising platform for targeted chemotherapy.

New Treatment of Medullary and Papillary Human Thyroid Cancer: Biological Effects of Hyaluronic Acid Hydrogel Loaded With Quercetin Alone or in Combination to an Inhibitor of Aurora Kinase.

The aim of this paper is based on the use of a hyaluronic acid hydrogel of Quercetin tested alone and in combination to an inhibitor of Aurora Kinase type A and B (SNS-314) on human medullary and papillary thyroid cancer cells. Biological investigations were focused on the cellular uptake of the hydrogel, cell viability, antioxidant, and cytokines secretion studies. Quercetin delivered from hydrogel show a time and CD44 dependent interaction with both cell lines with significant anti-inflammatory effects. Combination of Quercetin and SNS-314 leads to a synergistic cytotoxic effect on medullary TT and papillary BCPAP cell lines with a significant reduction of the IC50 value. These results, highlights the importance of synergistic effect of the hyaluronic acid hydrogel of Quercetin with SNS-314 in the regulation of human thyroid cancer cell proliferation and emphasize the anti-tumor activity of these molecules. J. Cell. Physiol. 231: 1784-1795, 2016. © 2015 Wiley Periodicals, Inc.

Use of polycaprolactone (PCL) as scaffolds for the regeneration of nerve tissue.

Adipose tissue is an easily accessible source of stem cells for use in tissue regenerative medicine. In the literature, different methods have been used to stimulate acquisition of neuronal characteristics by adipose-derived stem cells (ADSC). Herein we study the growth and neuronal differentiation potential of ADSC seeded onto a porous polycaprolactone (PCL) scaffold. The objective of this study is to demonstrate that PCL can be used as a scaffold to support reconstruction of new nervous tissue using adipose stem cells. We have previously shown that undifferentiated ADSC adhere and grow on PCL. Herein we show that, after culture on PCL in neuronal differentiation medium, ADSC expressed molecular markers characteristic of neuronal cells (ß-tubulin-III, Neuron-Specific Enolase (NSE), Nestin) and secrete brain derived neurotrophic factor (BDNF) and nerve growth factor (NGF). This study suggests that PCL can be used as a scaffold to generate nervous tissue in vitro. PLC has excellent mechanical properties and a slow degradation rate. Moreover, on the basis of our results, we propose that PCL could be used for to make in vitro, scaffold coated with neuronal cells derived from Adipose stem cells (ADSC). Neuronal cells-coated PCL could find several applications to replace damaged area of ​​the body; for example, a possible use could be the generation of nerves.

Therapy with autologous adipose-derived regenerative cells for the care of chronic ulcer of lower limbs in patients with peripheral arterial disease.

BACKGROUND: An ulcer is a trophic lesion with loss of tissue that often has a multifactorial genesis. It typically diverges from the physiologic processes of regeneration because it rarely tends to heal spontaneously. In this study, we used purified adipose-derived stem and regenerative cells (ADRCs) extracted from autologous fat, for the care of chronic ulcers of the lower limbs of arteriopathic patients. The primary objective of this study was complete re-epithelization of chronic ulcers; the secondary objective was a decrease in diameter and depth. METHODS: From January 2010 to January 2012, 20 patients with peripheral arterial disease, with an ankle-brachial index between 0.30-0.40, in the age range 60-70 y (14 men and six women), with chronic ulcers of the lower limb, were involved in the study. Only 10 arteriopathic patients (seven men and three women) with chronic ulcers of the lower limb were surgically treated. Using the Celution system, we isolated a solution of ADRCs in about 150 min. The isolated cells were injected through a 10-mL syringe into the edges of the ulcer, taking care to spread it in all directions. Using a small amount of Celution extract, we performed cell characterization by flow cytometry analysis and cell viability assay. RESULTS: We monitored patients treated with ADRC or untreated at 4, 10, 20, 60, and 90 d. In all cases treated with ADRC, we found a reduction in both diameter and depth of the ulcer, which led to a decrease in pain associated with the ulcer process. In six of 10 cases there was complete healing of the ulcer. Characterization of the cells by FACS clearly showed that the ADRC cells contained adipose-derived stem cells. Viability assays demonstrated that partial or total closure of the ulcer was attributable exclusively to ADRC cells present in the Celution extract, and not to growth factors extracted during the process of purification of the Celution and injected together with the cells. CONCLUSIONS: For the first time, the Celution method has been applied for the care of chronic ulcers in the lower extremity of patients with peripheral arterial disease. Our results demonstrate that the technique is feasible for autologous cell application and is not associated with adverse events. Moreover, the transplantation of autologous stem cells extracted with Celution may represent a valuable method for the treatment of chronic ulcers in lower limbs of arteriopathic patients.

Environmental scanning electron microscopy gold immunolabeling in cell biology.

Immunogold labeling (IGL) technique has been utilized by many authors in combination with scanning electron microscopy (SEM) and transmission electron microscopy (TEM) to obtain the identification/localization of receptors and antigens, both in cells and tissues. Environmental scanning electron microscopy (ESEM) represents an important tool in biomedical research, since it does not require any severe processing of the sample, lowering the risk of generating artifacts and interfere with the IGL procedure. The absence of metal coating could yield further advantages for our purpose as the labeling detection is based on the atomic number difference between nanogold spheres and the biological material. Using the gaseous secondary electron detector, compositional contrast is easily revealed by the backscattered electron component of the signal. In spite of this fact, only few published papers present a combination of ESEM and IGL. Hereby we present our method, optimized to improve the intensity and the specificity of the labeling signal, in order to obtain a semiquantitative evaluation of the labeling signal.In particular, we used a combination of IGL and ESEM to detect the presence of a protein on the cell surface. To achieve this purpose, we chose as an experimental system 3T3 Swiss albino mouse fibroblasts and galectin-3.

Alcohol dehydrogenase from the hyperthermophilic archaeon Pyrobaculum aerophilum: stability at high temperature.

The structural and stability properties of a novel zinc-dependent alcohol dehydrogenase from the hyperthermophilic archaeon Pyrobaculum aerophilum (PyAeADHII) were investigated by Fourier transformed infrared spectroscopy (FTIR). This enzyme is a thermostable homo-tetramer belonging to the GroES-fold motif proteins characterized by an irregular ß-barrel conformation. Our results revealed a protein with a secondary structure rich in ß-sheet (32% of the total secondary elements) and it showed a three-step thermal unfolding pathway. The complete enzyme denaturation was preceded by the formation of a relaxed tertiary/quaternary structure and previously by an excited native-like conformation. Two-dimensional correlation spectroscopy analysis (2D-COS) and differential scanning calorimetry (DSC) experiments supported these data and allowed us to determine the protein melting temperature at 96.9 °C as well as to suggest the sequence of the events that occurred during the protein denaturation process.

Growth and endothelial differentiation of adipose stem cells on polycaprolactone.

Adipose tissue is a readily available source of multipotent adult stem cells for use in tissue engineering/regenerative medicine. Various growth factors have been used to stimulate acquisition of endothelial characteristics by adipose-derived stem cells (ADSC). Herein, we study the growth and endothelial differentiation potential of ADSC seeded onto a porous polycaprolactone (PCL) scaffold. The objective of this study is to demonstrate that PCL is a good material to be used as a scaffold to support reconstruction of new endothelial tissue using adipose stem cells. We found that undifferentiated ADSC adhere and grow on PCL. We show that, after culture in endothelial differentiation medium, ADSC were positive to LDL uptake and expressed molecular markers characteristic of endothelial cells (CD31; eNOS and vWF). In addition, our study defines the time required for the differentiation of ADSC directly onto PCL. This study suggests that PCL can be used as a scaffold to generate endothelial tissue in vitro. PLC has excellent mechanical properties and a slow degradation rate. Moreover, based on our results, we propose that PCL could be used to graft scaffolds coated with endothelial cells derived from ADSC stem cells. Endothelial cells-coated PCL could find several applications to replace damaged area of the body; for example, a possible use could be the generation of vascular grafts.

Analysis of interaction partners for eukaryotic translation elongation factor 1A M-domain by functional proteomics.

The eukaryotic translation elongation factor 1A (eEF1A), besides to its canonical role in protein synthesis, is also involved in several other cellular processes, depending on changes in cellular location, cell type, concentration of ligands, substrates or cofactors. Therefore eEF1A is a moonlighting protein that participates to a network of molecular interactions involving its structural domains. Since the identification of novel protein-protein interactions represents important tasks in post-genomic era, the interactome of eEF1A1 M-domain was investigated by using a proteomic approach. To this purpose, the eEF1A1 M-domain was fused with glutathione-S-transferase (GST) and Strep-tag (ST) at it's N- and C-terminal, respectively. The recombinant protein (GST-M-ST) was purified and incubated with a mouse embryo lysate by applying an affinity chromatography strategy. The interacting proteins were separated by SDS-PAGE and identified by peptide mass fingerprinting using MALDI-TOF mass spectrometry. Besides the known partners, the pool of interacting proteins contained sorbin, a polypeptide of 153 amino acids present in SH3 domain-containing adaptor proteins, such as SORBS2. This interaction was also assessed by Western blot on immunoprecipitate from mouse embryo or H1355 cell lysates with anti-eEF1A or anti-SORBS2 antibodies and on eEF1A1-His pull-down from H1355 cell lysate with antibody anti-SORBS2. Furthermore, the interaction between eEF1A and SORBS2 was also confirmed by confocal microscopy and FRET analysis. Interestingly, a co-localization of SORBS2 and eEF1A was evidenced at level of plasma membrane, thus suggesting the involvement of eEF1A1 in novel key signal transduction complexes.

Properties and evolution of an alcohol dehydrogenase from the Crenarchaeota Pyrobaculum aerophilum.

The gene encoding a novel alcohol dehydrogenase (ADH) that belongs to the medium chain dehydrogenase/reductase (MDR) superfamily was identified in the hyperthermophilic archaeon, Pyrobaculum aerophilum. The P. aerophilum ADH gene (Pae2687) was over-expressed in Escherichia coli, and the protein (PyAeADHII) was purified to homogeneity and characterized. The PyAeADHII belongs to a medium chain class because its monomer size is 330 residues and even if it is structurally similar to other enzymes belonging to MDR superfamily, it lacks key residues involved in the coordination of the catalytic Zn ion and in the binding of alcoholic substrates typical of other ADHs. Consistently, PyAeADHII does not show activity on a large number of alcohols, aldheydes or ketones. It is active only when alpha-tetralone is used as a substrate. The enzyme has a strict requirement for NADP(H) as the coenzyme and has remarkable thermophilicity, displaying activity at temperatures up to 95 degrees C. The study of the metabolic pathways of P. aerophilum can provide information on the evolution of genes and enzymes and may be crucial for understanding the evolution of eukaryotic cells.

Beta-tricalcium phosphate 3D scaffold promote alone osteogenic differentiation of human adipose stem cells: in vitro study.

Human adipose tissues surgically resected from the subcutaneous abdominal region were enzymatically processed to obtain Human Adipose Stem cells (fibroblast-like adipose tissue-derived stromal cells-ADSC-FL) that were immunophenotypically characterized using a panel of mesenchymal markers by flow cytometry. The formation of new hydroxyapatite crystals in culture dishes, by differentiating cells, further demonstrate the osteogenic potential of purified cells. The aim of this study was to evaluate the osteogenic differentiation potential of ADSC-FL seeded onto a porous beta-tricalcium phosphate (beta-TCP) matrix. ADSC-FL was cultured on the beta-TCP matrix in medium with or without osteogenic differentiation additives. Time-dependent cell differentiation was monitored using osteogenic markers such as alkaline phosphatase (activity assay), osteocalcin and ostopontin (ELISA method) expression. Our results reveal that beta-TCP triggers the differentiation of ADSC-FL toward an osteoblastic phenotype irrespective of whether the cells are grown in a proliferative or a differentiative medium. Hence, a beta-TCP matrix is sufficient to promote osteoblastic differentiation of ADSC-FL. However, in proliferative medium, alkaline phosphatase activity was detected at lower level respect to differentiative medium and osteocalcin and osteopontin showed an expression delay in cells cultured in proliferative medium respect to differentiative one. Moreover, we observed an increase in FAK phosphorylation at level of tyrosine residue in position 397 (Western-blot) that indicates a good cell adhesion to beta-TCP scaffold. In conclusion, our paper demonstrates that a three-dimensional beta-TCP scaffold in vitro triggers on its own the differentiation of ADSC-FL toward an osteoblastic phenotype without the need to use differentiative media.

Galactosyl derivative of N(omega)-nitro-L-arginine: study of antiproliferative activity on human thyroid follicular carcinoma cells.

The methyl ester prodrug of N(omega)-nitro-L-arginine (L-NAME) has been reported to exert anticancer effects against several human tumors, including thyroid carcinoma, by inhibiting nitric oxide synthase (NOS). However, chronic administration of L-NAME has often led to adverse events causing cardiovascular alterations due to its potential toxic effect. Here we report for the first time the synthesis of the galactosyl ester prodrug of N(omega)-nitro-L-arginine, NAGAL, a prodrug capable of inhibiting NOS more efficiently and with fewer adverse events than its parent drug. For this purpose RO82-W-1, a thyroid cell line derived from human follicular carcinoma, was used. MTT test results showed that NAGAL affected cell viability to a significantly greater extent than did L-NAME. Moreover, fluorescence activated cell sorter (FACS) analyses revealed that NAGAL, compared to L-NAME, was able to reduce nitric oxide (NO) production as well as increase the percentage of apoptotic thyreocytes. Western blot further confirmed the reduction in NOS-II expression by NAGAL. Finally, by using the LC-MS technique, we found that NAGAL elicited a higher increase in N(omega)-nitro-L-arginine (NA) concentration than did L-NAME. Thus, this study suggests that NAGAL could be considered a potential therapeutic tool for those pathologies involving an overproduction of NO, including thyroid carcinoma.

Cell surface protein detection with immunogold labelling in ESEM: optimisation of the method and semi-quantitative analysis.

In this work we used a combination of immunogold labelling (IGL) and environmental scanning electron microscopy (ESEM) to detect the presence of a protein on the cell surface. To achieve this purpose we chose as experimental system 3T3 Swiss Albino Mouse Fibroblasts and galectin-3. This protein, whose sub-cellular distribution is still under discussion, is involved in a large number of cell physiological and pathological processes. IGL technique has been utilised by many authors in combination with SEM and TEM to obtain the identification/localisation of receptors and antigens, both in cells and tissues. ESEM represents an important tool in biomedical research, since it does not require any severe processing of the sample, lowering the risk of generating artefacts and interfere with IGL procedure. The absence of metal coating could yield further advantages for our purpose as the labelling detection is based on the atomic number difference between Nanogold spheres and the biological material. Using the gaseous secondary electron detector (GSED) compositional contrast is easily revealed by the backscattered electrons component of the signal. In spite of this fact, only few published papers present a combination of ESEM and IGL. Hereby we present our method, optimised to improve the intensity and the specificity of the labelling signal, in order to obtain a semi-quantitative evaluation of the labelling signal.

Adhesion and proliferation of fibroblasts on RF plasma-deposited nanostructured fluorocarbon coatings: evidence of FAK activation.

We used combined plasma-deposition process to deposit smooth and nanostructured fluorocarbon coatings on polyethylenethereftalate (PET) substrates, to obtain surfaces with identical chemical composition and different roughness, and investigate the effect of surface nanostructures on adhesion and proliferation of 3T3 Swiss Albino Mouse fibroblasts. Untreated PET and polystyrene (PS) were used as controls for cell culture. We have found that the statistically significant increase of cell proliferation rate and FAK (a nonreceptor tyrosine kinase) activation detected on ROUGH fluorocarbon surfaces is due to the presence of nanostructures. Changes in cytoskeletal organization and phospho FAK (tyr 397) localization were evident after 60 min on cells adhering to ROUGH surfaces. This change was characterized by the formation of actin stress fibers along lamellar membrane protrusion instead of usual focal contacts. Also the morphology of the adhering fibroblasts (60 min) adhering on ROUGH surfaces was found quite different compared to cells adhering on smooth ones.

A critical overview of ESEM applications in the biological field.

Scanning Electron Microscope (SEM) is a powerful research tool, but since it requires high vacuum conditions, the wet materials and biological samples must undergo a complex preparation that limits the application of SEM on this kind of specimen and often causes the introduction of artifacts. The introduction of Environmental Scanning Electron Microscope (ESEM), working in gaseous atmosphere, represented a new perspective in biological research. Despite the fact that many biological applications have demonstrated the convenience of ESEM, the full potentialities of this technology are still under investigation. In this review, the exploration of the recent literature data confronted with the first results obtained in our experimental work suggest that ESEM represents an important extension of conventional scanning microscopy.

Smart materials as scaffolds for tissue engineering.

In this review, we focused our attention on the more important natural extracellular matrix (ECM) molecules (collagen and fibrin), employed as cellular scaffolds for tissue engineering and on a class of semi-synthetic materials made from the fusion of specific oligopeptide sequences, showing biological activities, with synthetic materials. In particular, these new "intelligent" scaffolds may contain oligopeptide cleaving sequences specific for matrix metalloproteinases (MMPs), integrin binding domains, growth factors, anti-thrombin sequences, plasmin degradation sites, and morphogenetic proteins. The aim was to confer to these new "intelligent" semi-synthetic biomaterials, the advantages offered by both the synthetic materials (processability, mechanical strength) and by the natural materials (specific cell recognition, cellular invasion, and the ability to supply differentiation/proliferation signals). Due to their characteristics, these semi-synthetic biomaterials represent a new and versatile class of biomimetic hybrid materials that hold clinical promise in serving as implants to promote wound healing and tissue regeneration.

From cell-ECM interactions to tissue engineering.

The extracellular matrix (ECM) consists of a complex mixture of structural and functional macromolecules and serves an important role in tissue and organ morphogenesis and in the maintenance of cell and tissue structure and function. The great diversity observed in the morphology and composition of the ECM contributes enormously to the properties and function of each organ and tissue. The ECM is also important during growth, development, and wound repair: its own dynamic composition acts as a reservoir for soluble signaling molecules and mediates signals from other sources to migrating, proliferating, and differentiating cells. Approaches to tissue engineering center on the need to provide signals to cell populations to promote cell proliferation and differentiation. These "external signals" are generated from growth factors, cell-ECM, and cell-cell interactions, as well as from physical-chemical and mechanical stimuli. This review considers recent advances in knowledge about cell-ECM interactions. A description of the main ECM molecules and cellular receptors with particular care to integrins and their role in stimulation of specific types of signal transduction pathways is also explained. The general principles of biomaterial design for tissue engineering are considered, with same examples.

Cationic polyelectrolyte hydrogel fosters fibroblast spreading, proliferation, and extracellular matrix production: Implications for tissue engineering.

Fibrous encapsulation is known to occur to many prosthetic implants and is thought to be due to the cells not adhering adequately to the surface. For developing new materials able to enhance cellular adhesion by mimicking extracellular matrix components, polyelectrolyte polymers, characterized by tunable surface charges, have been proposed. Here we demonstrate that panoply of cell functions over a two-dimensional substratum is influenced by surface charge. We have at first generated structurally related polyelectrolyte substrata varying in their positive surface charge amount and subsequently evaluated a variety of behaviors of human primary fibroblasts seeded on these polymers. The proportion of adherent, spreading, and proliferating cells was increased significantly on cationic hydrophilic surfaces when compared with the neutral base surface. The extent of cell spreading correlated with cytoskeleton organization as assessed using immunofluorescence techniques. In the key experiment, the presence of cationic charges on cell adhesion-resistant neutral surface increased the synthesis of collagen I and III, the release of their metabolites, and the expression of their mRNA by fibroblasts. Interestingly, the scarce collagen deposits on neutral polymer consisted, for the most part, of collagen I while collagen III was present only in traces probably due to the secretion of metalloproteinase-2 by non-adherent fibroblasts. Taken together, these results show that polyelectrolyte films may promote the attachment of fibroblast cells as well as their normal secretory phenotype. Both effects could be potentially useful in integrating soft connective tissue to the implant, decreasing the chance of its fibrous encapsulation.