Cancer cells present a particular metabolic behavior. We hypothesized that the progression of bladder cancer could be accompanied by changes in cells glycolytic profile. We studied two human bladder ...cancer cells, RT4 and TCCSUP, in which the latter represents a more invasive stage. The levels of glucose, pyruvate, alanine and lactate in the extracellular media were measured by Proton Nuclear Magnetic Resonance. The protein expression levels of glucose transporters 1 (GLUT1) and 3 (GLUT3), monocarboxylate transporter 4 (MCT4), phosphofructokinase-1 (PFK1), glutamic-pyruvate transaminase (GPT) and lactate dehydrogenase (LDH) were determined. Our data showed that glucose consumption and GLUT3 levels were similar in both cell lines, but TCCSUP cells displayed lower levels of GLUT1 and PFK expression. An increase in pyruvate consumption, concordant with the higher levels of lactate and alanine production, was also detected in TCCSUP cells. Moreover, TCCSUP cells presented lower protein expression levels of GPT and LDH. These results illustrate that bladder cancer progression is associated with alterations in cells glycolytic profile, namely the switch from glucose to pyruvate consumption in the more aggressive stage. This may be useful to develop new therapies and to identify biomarkers for cancer progression.
•Metabolic phenotype of less and high invasive bladder cancer cells was studied.•Bladder cancer progression involves alterations in cells glycolytic profile.•More invasive bladder cancer cells switch from glucose to pyruvate consumption.•Our results may help to identify metabolic biomarkers of bladder cancer progression.
Hydrogels based on biopolymers like Gum Arabic (GA) usually show low applicability due to weak mechanical properties. To overcome this issue, (nano)fillers are utilized as reinforcing agents. Here, ...GA hydrogels were reinforced by chitin nanowhiskers (CtNWs, aspect ratio of 14) isolated from the biopolymer chitin through acid hydrolysis. Firstly, GA was chemically modified with glycidyl methacrylate (GMA), which allowed its crosslinking by free radical reactions. Next, hydrogel samples containing different concentrations of CtNWs (0–10 wt%) were prepared and fully characterized. Mechanical characterization revealed that 10 wt% of CtNWs promoted an increase of 44% in the Young's modulus and 96% the rupture force values compared to the pristine hydrogel. Overall, all nanocomposites were stiffer and more resistant to elastic deformation. Due to this feature, the swelling capacity of the nanocomposites decreased. GA hydrogel without CtNWs exhibited a swelling degree of 975%, whereas nanocomposites containing CtNWs exhibited swelling degrees under 725%.
•Chitin nanowhiskers were introduced in a Gum Arabic hydrogel matrix to obtain nanocomposites.•The nanowhiskers were homogeneously dispersed and distributed through the nanocomposite.•The hydrogel was mechanically reinforced even using low amounts of nanowhiskers.•The swelling ability of the nanocomposites can be tailored varying the amount of nanowhiskers.
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•HmimHSO4 and bio-renewable sources were used to obtain hydrogel-based materials.•Ionic liquid to solubilize polysaccharides is considered an innovative method.•Hydrogels showed them ...had excellent stabilities and larger swelling capacities.•Excellent biocompatibility upon both VERO and HT29 cells.
HmimHSO4 ionic liquid (IL) and bio-renewable sources as chitosan (CHT) and chondroitin sulfate (CS) were used to yield hydrogel-based materials (CHT/CS). The use of IL to solubilize both polysaccharides was considered an innovative way based on “green chemistry” principle, aiming the production of CHT/CS blended systems. CHT/CS hydrogels were carried out in homogeneous medium from short dissolution times. The hydrogels were characterized and achieved with excellent stabilities (in the 1.2–10pH range), larger swelling capacities, as well as devoid of cytotoxicity towards the normal VERO and diseased HT29 cells. The CHT/CS hydrogels carried out in HmimHSO4 could be applied in many technological purposes, like medical, pharmaceutical, and environmental fields.
Pectin and chitosan films containing glycerol (Gly) at 5, 10, 15, 20, 30, and 40 wt % were prepared in an aqueous HCl solution (0.10 M) by the solvent evaporation method. The unwashed film (UF) ...containing 40 wt % Gly (UF40) had elongation at break (
, %) of 19%. Washed films (WFs) had high tensile strength (
> 46 MPa) and low elongation at break (
, <5.0%), enabling their use in food packaging applications. The polymers' self-assembling occurred during the washing, increasing the stiffness. The XPS analysis suggests that some HCl is lost during the drying process, resulting in a low acid content on the UF surfaces. The UF40 (at 5.0 mg/mL) exhibits cytocompatibility toward mammalian cells and antimicrobial and anti-adhesive properties against
. The remaining HCl in the UF40 can be a disadvantage for food packaging applications; the UF40 (∅ = 8.5 mm; 55 μm thickness) releases H
O
/HCl, reducing the pH to approximately 3.0 when kept in 200 mL distilled water for approximately 30 min. Therefore, we propose the use of UF40 to coat commercial food packaging. The UF40 has low permeability to water vapor and oxygen and works as a barrier against ultraviolet light. The UF40 is also colorless and completely transparent. The UF40 maintained tomatoes' structural integrity for 18 days at room temperature with no oxidation or microorganism contamination. This paper presents a critical viewpoint concerning chitosan-based films with antimicrobial activities.
Chitosan/chondroitin sulfate (CHT/CS) curcumin-charged hydrogels were prepared through polyelectrolytic complexation (PEC) following two methodologies (PEC-CUR and PEC-T-CUR) and were applied on ...apoptosis of HeLa, HT29 and PC3 cancer cells. PEC-T-CUR (ionic liquid (IL) mixed using ultraturrax homogenizer) results show to be far better than for PEC-CUR (IL mixed using magnetic stirring), with IC50 being improved 5.13 times to HeLa cancer cells (from 1675.2 to 326.7 μg mL−1). PECs produced by this methodology presented favorable characteristics, such as particle size, hydrophobicity, pH swelling. Beyond this, the IL was quantitatively recovered in both cases. CUR entrapment levels were hugely loaded into PEC at around 100%. Swelling, dissolution/degradation, and pHpzc assays showed that PECs may positively act in several environments, releasing the CUR, the CHT and CS as well. Characterization through FTIR, SEM, TEM, TGA, DSC, and WAXS confirmed CUR presence in both types of PECs, and cytotoxic studies showed the significant anticancer effects of CUR-containing PECs.
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•N,N-Dimethyl chitosan and N,N,N-trimethyl chitosan nanoparticles were successful obtained.•Curcumin was loaded into nanoparticles and release studies were performed in SGF and SIF.•Nanoparticles ...loaded with curcumin have greater biocompatibility on healthy VERO cells.•Loaded N,N,N-trimethyl chitosan nanoparticles has slight cytotoxicity on SiHa cancerous cells.
Nanoparticles (NPs) based on N,N-dimethyl chitosan (DMC) and N,N,N-trimethyl chitosan (TMC), physical crosslinked with sodium tripolyphosphate (TPP) were successful obtained, using water/benzyl alcohol emulsion system. NPs morphologies were evaluated by Scanning Electron Microscopy and Transmission Electron Microscopy. NPs were characterized by Infrared Spectroscopy (FTIR), Thermogravimetric Analysis, Zeta Potential, Differential Scanning Calorimetry and Wide-angle X-ray Scattering. Curcumin (CUR) was loaded onto NPs and controlled release studies were evaluated in simulated intestinal fluid and in simulated gastric fluid. Cytotoxicity assays showed only loaded TMC/TPP particles containing CUR were slightly cytotoxic on human cervical tumor cells (SiHa cells), concerning unloaded TMC/TPP particles. Conversely, loaded NPs (TMC/TPP/CUR and DMC/TPP/CUR), especially TMC/TPP/CUR sample presented greater biocompatibility toward healthy VERO cells than unloaded NPs (TMC/TPP and DMC/TPP).
To obtain pectin-based films is challenging due to the aqueous instability of polyelectrolyte mixtures. We overcome this issue by blending chitosan to pectin of high O-methoxylation degree (56%), ...followed by solvent evaporation. A durable film containing 74 wt% pectin content was produced and used as an adsorbent material toward Cu(II) ions. Kinetic and adsorption equilibrium studies showed that the pseudo-second-order and Sips isotherm models adjusted well to the experimental data, respectively. Langmuir isotherm indicated a maximum adsorption capacity (qm) for Cu(II) removal of 29.20 mg g−1. Differential scanning calorimetry, contact angle measurements, and X-ray photoelectron spectroscopy confirm the adsorption. The chemisorption plays an essential role in the process; thereby, the film reusability is low. After adsorption, the cytocompatible film/Cu(II) pair prevents the proliferation of Escherichia coli.
•A physically crosslinked film contains high pectin content (74 wt%).•The film presents sorption capacity for Cu(II) ions of 29.20 mg g−1.•The chemisorption plays an essential role in the Cu(II) adsorption.•After adsorption, the film/Cu(II) has cytocompatibility for mammalian cells.•The film/Cu(II) prevents the spreading of E. coli on its surface.
Strategies for incorporating water-insoluble photosensitisers (PS) in drug delivery systems have been extensively studied. In this work, we evaluate the formation, characterisation, drug sorption ...studies, and cytotoxicity of chitosan (CHT)/chondroitin sulphate (CS) polyelectrolyte complexes (PECs) coated with polystyrene-block-poly(acrylic acid) (PS-b-PAA) nanoparticles (NPs) loaded with chloroaluminum phthalocyanine (AlClPc). The PECs were characterised by infrared spectroscopy (FTIR), differential scanning calorimetric (DSC), X-ray diffraction (XRD), and scanning electron microscopy (SEM). The PS-b-PAA NPs on the PEC surface was confirmed by scanning electron microscopy (SEM). Additionally, optical images distinguished the PEC structures containing PS-b-PAA or PS-b-PAA/AlClPc from the unloaded PEC. Kinetic and equilibrium studies investigate the sorption capacity of the PEC/PS-b-PAA toward AlClPc. The encapsulation efficiency reached 95% at 190 μg mL−1 AlClPc after only 15 min. The Brunauer-Emmett-Teller (BET) isotherm and pseudo-second-order kinetic fitted well to the experimental data. The PS-b-PAA NPs on the PEC surfaces increase the AlClPc bioavailability and the PEC structure stabilizes the PS-b-PAA/AlClPc nanostructures. The materials were cytocompatible upon healthy VERO (kidney epithelial cells), and cytotoxic against colorectal cancerous cells (HT-29 cells). For the first time, we associate PS-b-PAA/AlClPc with a hydrophilic and cytocompatible polysaccharide matrix. We suggest the use of these materials in strategies to treat cancer by using photodynamic therapy.
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•Polyelectrolyte complex (PECs) coacervates were created from polymer blends in an ionic liquid.•Polystyrene-block-poly(acrylic acid) nanoparticles were adsorbed on the PEC surfaces.•The polystyrene-block-poly(acrylic acid)/PEC pair was loaded with chloroaluminum phthalocyanine.•We suggest the use of these materials to treat cancer using photodynamic therapy.
We present chitosan (CHT)/heparin (HP) polyelectrolyte complexes (PECs) that quickly adsorb citrate-capped silver nanoparticles (AgNPs). CHT/HP blends in ionic liquid (HMImHSO4) form durable PECs ...after precipitation in water. CHT/HP PECs have positive Zeta potentials (higher than +20 mV). They adsorb citrate-capped AgNPs (Zeta potential of - 12.25 mV) synthesized from Turkevich's method. PEC/AgNPs composites are characterized by spectroscopic, thermal, and microscopy analyses. AgNPs on the PEC surfaces are confirmed by transmission electron microscopy. PECs adsorb AgNPs from aqueous suspensions, achieving ≈ 95% of removal (17.18 μg of AgNPs per milligram of PEC) after only 10 min. The pseudo-second-order kinetic model adjusted well to the experimental data. The PECs release approximately 11.80 μg/mg Ag+ (66%) compared to the initial adsorbed AgNPs content (17.18 μg/mg) after 7200 min at pH 2.0. The PECs present low swelling degrees (between 130 and 150%), supporting high stability in water. PEC/AgNPs composites promote significant bactericidal activity toward Staphylococcus aureus and Escherichia coli between 0.25 and 0.5 mg/mL. This study shows a new strategy to create hybrid polysaccharide/AgNPs composites. PECs can stabilize the AgNPs and release Ag+ ions, supporting antimicrobial materials.
•Polyelectrolyte complexes (PECs) were synthesized using a green solvent.•95% of the citrate-capped silver nanoparticles were adsorbed on PECs' surface.•Citrate-capped silver nanoparticles are visible on PECs.•Hybrid materials present low heparin release at simulated fluids.•The Citrate-capped silver nanoparticles sorption is faster than the Ag+ ion release.
Recycling of post-consumed composites based on thermosets reinforced with glass fibre (GF) uses different methods such as mechanical processing, high voltage fragmentation, thermal, and chemical ...treatments. Chemical treatments are a more interesting methodology because they allow the recovery of cleaner and polymeric matrices free glass fibres. However, depending on the solvent employed, limitations in chemical treatments such as a decrease in mechanical properties and low rate GF recovery are very common. In this paper, an original and green technology is proposed to overcome these limitations. Such technology uses D-limonene at sub- or supercritical conditions (ScD-limonene) in the absence of catalysts or auxiliary molecules, such as supercritical carbon dioxide (ScCO2), making the process more eco-friendly and so contributing to sustainability when compared to other processes that use catalysts or auxiliary molecules. Recovering almost 100% GF and preventing the deterioration or loss of properties, of the recovered GF (RGF) were achieved while the partially degraded resin can be separated and reused as a charge material in new composite formulations. Recycling glass fibre-reinforced polyester resin at composite/solvent (at sub-supercritical conditions) ratios up to 0.15 g mL−1 was possible due to the high solvation power of sub- and supercritical D-limonene. Scanning electron microscopy (SEM) images, X-ray photoelectron spectroscopy (XPS), and tensile strength analyses revealed that RGF exhibits morphological, chemical, and mechanical reinforcing capabilities comparable to virgin GF (VGF). Mass spectrometry of the resin residue (after sub- or supercritical D-limonene treatment) showed predominant fragmentation-patterns inferring the occurrence of partial degradation. The results found in this study, such as short reaction times of 45–60 min, and high recovery efficiencies ≈100%, are highly desirable for practical purposes. Furthermore, the preservation of the mechanical reinforcing properties of RGF at 64–85%, the ease of separation of the products, and solvent reuse, make this technology promising as compared to others. Based on the obtained results, ScD-limonene treatment can be employed as an efficient and eco-friendly strategy to recover GF from waste materials.
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•D-limonene at sub- and supercritical conditions was used to recover glass fibre.•100% glass fibres were recovered at absence of catalysts or auxiliary molecules.•Short reaction time is employed up 60 min.•Composites containing recovered glass fibre showed good tensile strength.•Simple protocol promotes the reversibility of hydrophobicity of recovered glass fibre.
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