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A red-emitting fluorescent Riboflavin (RF)/Polyvinylpyrrolidone (PVP)-coated silver nanoparticles system, λ

Eggplant peels (Solanum melongena L.) constitute a promising source of phenolic compounds, flavonoids, and anthocyanins that are beneficial for human health. The objectives of this study were to extract the polyphenolics from eggplant peels and microencapsulation in selected polymers, such as pectin, carboxymethylcellulose and whey proteins hydrolysates by freeze-drying. A combination of ethanolic with ultrasound-assisted methods was used for the extraction, leading to an extract with antioxidant activity of 157.82 ± 9.46 mmol Trolox/g dry weight. The next experiment was to obtain bioactive peptide, both by experimental and predictive methods, which were further used as coating materials. The bioinformatics tools were used for checking the susceptibility of α-lactalbumin and β-lactoglobulin for digestion with thermolysin. The anthocyanins were encapsulated in different combinations of selected polymers, with encapsulation efficiency up to 77.60 ± 1.92%, highlighting a higher microencapsulation efficiency of carboxymethylcellulose to incorporate anthocyanins. Our results suggested whey peptides had a role in regulating the microencapsulation patterns, whereas carboxymethylcellulose and pectin favored filamentous structuring and double encapsulation, respectively. The in vitro tests showed high biocompatibility of powders cultivated in a cell culture of murine fibroblasts. A significant protective effect in simulated digestion was observed, with a controlled release in the intestinal juice. Accelerated storage stability test showed an increase in antioxidant activity.

Hederagenin, a saponin known for its therapeutic effect was isolated from leaves of Hedera helix. Hederagenin was obtained by repeated maceration of ground plant material in 95% (v/v) ethanol. The ethanolic extract was subjected to acid hydrolysis and purification with acetonitrile. Isolated hederagenin (IHe) was analyzed by HPLC-MS/MS and compared to standard hederagenin. In vitro cytotoxicity of IHe was tested in a culture of fibroblast cells from NCTC clone L929 cell line by MTT assay, using dioscin as positive control. For the determination of IHe antitumor effect, in vitro tests were performed in a culture of human cervix carcinoma Hep-2 cells cultivated in the presence of different concentrations of sample for 48 h. IHe was biocompatible in the range of concentrations 2-200 mg/mL, in NCTC cell culture. The compound showed cell cytotoxicity in the concentration range of 100-400 mg/mL, in Hep-2 cell culture, revealing its antitumor activity. These results demonstrated the possible use of hederagenin isolated from H. helix extract as an antitumor agent.

The collagen hydrolysate (HC) and silver nanoparticles (AgNPs) effect on the mechanical, thermal, in vitro degradation, cytotoxicity and antifungal properties of polylactic acid (PLA) plast...

Freshwater fish skin and bones are usually by-products of the fish processing industry. [...]

Cancer is a terrible disease that is spread around the world. [...]

Grape pomace, a by-product of the winemaking process, is a source of valuable natural compounds [...]

The present study describes a comprehensive investigation of the spectroscopic characteristics, stability and in vitro antioxidant and cytotoxic properties of the Flavin MonoNucleotide (FMN) and Flavin Adenine Dinucleotide (FAD) in Dextran70 (Dx70) and Dx70/phospatidylcholine (PC) biomimetic systems by means of the UV–Vis absorption, fluorescence spectroscopy, chemiluminescence and Neutral Red assay. The affinity of FMN, FAD and the precursor riboflavin (RF) to an unsaturated phospholipid bilayer model as well as the location of the probes within the lipid bilayer were assessed from united-atom molecular dynamics simulations carried out on an unsaturated phospholipid bilayer model system, and the theoretical and experimental characterization of the two probes within biomembranes was complemented with the light microscopy survey of the cell morphology of L929 fibroblast cells cultivated in the presence of various dosage of FAD/FMN. In lipid bilayers, FMN/FAD resulted in a noticeable improvement of the antioxidant activity (the scavenging of reactive oxygen species up to 40%) and a significant effect on cellular viability in the L929 fibroblast cells. The results are important in the oxidative stress process concerning the redox reactions of flavins in humans as well as in further studies on different systems belonging to the category of flavoenzymes/flavoproteins, required for cellular respiration.

Angiogenesis is a physiological process involving the growth of new blood vessels, which provides oxygen and required nutrients for the development of various pathological conditions. In a tumor microenvironment, this process upregulates the growth and proliferation of tumor cells, thus any stage of angiogenesis can be a potential target for cancer therapies. In the present study, chitosan and his derivatives have been used to design novel polymer-based nanoparticles. The therapeutic potential of these newly designed nanoparticles has been evaluated. The antioxidant and MTT assays were performed to know the antioxidant properties and their biocompatibility. The in vivo antiangiogenic properties of the nanoparticles were evaluated by using a chick Chorioallantoic Membrane (CAM) model. The obtained results demonstrate that chitosan derivatives-based nanostructures strongly enhance the therapeutic effect compared to chitosan alone, which also correlates with antitumor activity, demonstrated by the in vitro MTT assay on human epithelial cervical Hep-2 tumor cells. This study opens up new direction for the use of the chitosan derivatives-based nanoparticles for designing of antiangiogenic nanostructured materials, for future cancer therapy.

The present work explores new hybrid bioactive, enzymatically degradable hydrogel nanocomposites. They are composed by stimuli-sensitive semi-interpenetrating collagen/poly(N-isopropyl acrylamide) polymeric matrix, Dellite® 67G and Cloisite® 93A nanoclays, and hydroxyapatite particles. Morphology of the hybrid hydrogel nanocomposites was examined by near infrared chemical imaging, X-ray diffraction, scanning electron microscopy, and transmission electron microscopy techniques. It has been found that the porous hydrogel nanocomposites showed a mix between intercalated and exfoliated structure, with interconnected pores and the inorganic material was evenly distributed in the polymeric matrix because of specific interactions between components. The collagen resistance against enzymatic degradation and the thermal stability were improved due to the protein encapsulation in the synthetic polymer matrix. The hydrogel nanocomposites showed suitable swelling characteristics for tissue engineering. In vitro cytocompatibility and cell viability revealed that the hybrid nanocomposites were non-cytotoxic for rat osteoblasts. These hybrid nanocomposites were designed as potential synthetic bone tissue engineering.

A new series of substituted N,N-bis-[(1H-pyrazol-1-yl)methyl]-aminohexadecane Mannich bases were synthesized, characterized by IR, 1 H NMR 13 C NMR, UV–Vis, MS and elemental analysis, and tested for their biological activity. All the synthesized compounds were tested for in vitro antimicrobial activity against a panel of selected bacterial and fungal strains using erythromycin and clotrimazole as standards. Most of the synthesized compounds demonstrated very good activity at minimum inhibitory concentrations (MICs). Compound 3b with an halogen atom into the pharmacophore structure exhibited the most significant activity against Bacillus subtilis (MIC = 0.007 μgmLL −1 ) versus erythromycin as standard. In vitro cytotoxicity of the new compounds was studied using MTT assay. The analysis of the test cells showed that the newly synthesized alkylaminopyrazoles derivatives were biocompatible until a concentration of 5 μgmL −1 ; two compounds presented a high degree of biocompatibility on the studied concentration range.

The synthesis and physicochemical characterization of riboflavin (RF) loaded Myrj52–silver nanoparticles (SNPs) were performed and their cytotoxic properties were evaluated. Transmission electron microscopy analysis showed the formation of colloidal spherical SNPs with an average size of ∼12 nm. The structure, stability, dynamics and conformation of human serum albumin (HSA) binding RF on SNPs have been studied. The influence of RF on the secondary structure of HSA in the presence of SNPs showed a predominant α-helix structure (61.7%). No changes induced by RF binding to HSA were observed. The cytotoxicity of RF and RF–HSA loaded Myrj52–SNPs was evaluated in vitro using the Neutral Red assay and cell morphology observations in a culture of L929 fibroblast cells. The results have relevance with regard to the RF loaded Myrj52–SNP formulation for pharmaceuticals.

Glycosaminoglycans (GAGs) are anionic straight chain polysaccharides with a wide range of [...]

The work aims to simulate in vitro, the antioxidant activity of riboflavin (RF) (Vitamin B2) in Polyethylene Glycols (PEGs) (Tween20 and Myrj52)/Bovine Serum Albumin (BSA) systems, using the chemiluminescent system luminol-hydrogen peroxide, in alkaline solution, Tris–HCl buffer, pH 8.5. The tested concentrations were 2–20 μM for RF and 0.06 to 0.6% for PEGs. It was found that 0.12% PEGs enhance the antioxidant activity of RF to higher and lower values, according to their molecular structure, Tween20 > Myrj52. RF has a pro-oxidant effect in the presence of BSA, while in the PEG/BSA systems, its antioxidant activity increases up to ~20%; a cross-linking of PEG to RF in the presence of BSA is considered. Additionally, studies by fluorescence spectroscopy on RF embedded in Tween20/BSA system-enhanced Tyrosine fluorescence contribution. In vitro cytotoxicity evaluation of RF in PEG/BSA systems was performed by Neutral Red assay and by monitoring lactate dehydrogenase release. PEG/BSA system offers great promise for enhancement of the RF antioxidant activity and biocompatibility, maintaining the integrity of the BSA, facts which are useful in the oxidative stress and drug delivery processes.

Chitosan is a non-toxic, biocompatible, biodegradable natural cationic polymer known for its low imunogenicity, antimicrobial, antioxidant effects and wound-healing activity. To improve its therapeutic potential, new chitosan-sulfonamide derivatives have been designed to develop new wound dressing biomaterials. The structural, morphological and physico-chemical properties of synthesized chitosan derivatives were analyzed by FT-IR, (1)H NMR spectroscopy, scanning electron microscopy, swelling ability and porosity. Antimicrobial, in vivo testing and biodegradation behavior have been also performed. The chitosan derivative membranes showed improved swelling and biodegradation rate, which are important characteristics required for the wound healing process. The antimicrobial assay evidenced that chitosan-based sulfadiazine, sulfadimethoxine and sulfamethoxazole derivatives were the most active. The MTT assay showed that some of chitosan derivatives are nontoxic. Furthermore, the in vivo study on burn wound model induced in Wistar rats demonstrated an improved healing effect and enhanced epithelialization of chitosan-sulfonamide derivatives compared to neat chitosan. The obtained results strongly recommend the use of some of the newly developed chitosan derivatives as antimicrobial wound dressing biomaterials.

Tuberculostatic drugs are the most common drug groups with global hepatotoxicity. Awareness of potentially severe hepatotoxic reactions is vital, as hepatic impairment can be a devastating and often fatal condition. The treatment problems that may arise, within this class of medicines, are mainly of two types: adverse reactions (collateral, toxic or hypersensitive reactions) and the initial or acquired resistance of Mycobacterium tuberculosis to one or more antituberculosis drugs. Prevention of adverse reactions, increase treatment adherence and success rates, providing better control of tuberculosis (TB). In this regard, obtaining new drugs with low toxicity and high tuberculostatic potential is essential. Thus, in this work, we have designed or synthesized new derivatives of isoniazid (INH), such as new Isonicotinoylhydrazone (INH-a, INH-b and INH-c). These derivatives demonstrated good biocompatibility, antimicrobial property similar to that of parent isoniazid and last but not least, a significantly improved Pharmacotoxicological profile compared to that of isoniazid.

In this paper, we present the fabrication and characterization of new chitosan-based membranes while using a new biotechnology for immobilizing alkaline phosphatase (ALP). This technology involved metal ions incorporation to develop new biopolymeric supports. The chemical structure and morphological characteristics of proposed membranes were evaluated by infrared spectroscopy (FT-IR) and the scanning electron microscopy technique (SEM). The inductively coupled plasma mass spectrometry (ICP-MS) evidenced the metal ion release in time. Moreover, the effect of Mg2+ on the enzymatic activity and the antibacterial investigations while using Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus bacteria, hemolysis, and biocompatibility behavior were studied. Immobilizing ALP into the chitosan membranes composition followed by the incorporation of Mg2+ led to polymeric supports with enhanced cellular viability when comparing to chitosan-based membranes without Mg2+. The results obtained evidenced promising performance in biomedical applications for the new biopolymeric supports that are based on chitosan, ALP, and metal ions.

Poly(vinyl chloride) (PVC) is the most widely used material for the production of medical devices such as intravenous fluid bags and tubing, enteral feeding, dialysis equipment and catheters. Despite of their numerous advantages, the plastic medical devices are non biodegradable and prone to microbial colonization causing biofilm associated infections which are difficult to treat and tend to chronicisation. A possible solution to surpass these limitations could be the fabrication of new biodegradable polymeric materials with optimized biocompatibility and antimicrobial properties. In this regard, biodegradable polymeric materials, such as poly(e-caprolactone) (PCL), poly(DL-lactic acid) (PLA) etc. have been considered the most desirable solution from the environment management point of view. In this paper, Alg(1%)Zn, Alg(2%)Zn, Alg(3%)Zn compounds were obtained from sodium alginate (AlgNa) crosslinked with ZnCl2. Antimicrobial activity of the AlgZn compounds was assessed by the microdilutions and the diffusion methods, towards Gram-positive and Gram-negative bacterial strains (reference and clinical isolates). The Alg(3%)Zn compound was selected as antimicrobial agent to obtain the biocomposites encoded: PLA/PCL/AlgZn0.1 and PLA/PCL/AlgZn0.3. The PLA/PCL sample was used as control. Antibiofilm activity against Staphylococcus xylosus, cytotoxic effect on mammalian cells and thermal analysis by DSC were investigated for the obtained biocomposites. The obtained results show that the addition of the Alg(3%)Zn compound in the biocomposites decreased the glass transition temperature as well as the degree of crystallinity both of the PCL and PLA components in samples. Although the results suggest that the biocomposites containing Alg(3%)Zn did not inhibit the staphylococcal colonization and mature biofilm formation, the high degree of biocompatibility of blends leads to conclusion that these materials could be used for the development of novel bioactive and biodegradable polymeric materials with medical applications.

The aim of this research was to investigate the chemical composition of Coreopsis tinctoria Nutt. fruits extract, to highlight the potential of ultrasound assisted extraction in the fast preparation of extracts rich in polyphenols using different solvents (55%, 78% and 96% hydrous ethanol) and to evaluate the antioxidant potential of formulated extracts. LC-MS/MS was used to characterize the ethanolic extract from Coreopsis tinctoria Nutt. dried fruits. The extract contains different flavonoids (marein, flavanomarein, quercetagetin-7-O-glucoside, okanin aurone, leptosidin, luteolin, apigenin) and phenolic acids (chlorogenic acid, caffeic acid). Several parameters that could affect extraction efficiency were evaluated. Finally, this study focused on determination of plant extracts total phenolic content and their antioxidant capacity. The experimental results allowed the selection of the optimum operating parameters leading to the highest total polyphenolic content, expressed as gallic acid equivalents, and avoiding the degradation of phenolic compounds (ethanol 55%; extraction temperature 323.15 K, extraction time 30 min, liquid/solid ratio 20/1). A good relationship between total phenolic content and antioxidant capacity was obtained.

In this study, three of the saponins present in leaves of Hedera helix L., &alpha, hederin, hederagenin, and hederacoside C were studied for their antiproliferative activity. The three saponins were analyzed in different concentrations by in vitro tests on normal fibroblasts cells and cervix ephitelial tumor cells. Determination of cytotoxicity and antitumor effects was performed using the MTT method. From the tested saponins, &alpha, hederin was biocompatible in normal fibroblasts cells at concentrations between 2&ndash, 10 &mu, g/mL. Its antiproliferative activity was exerted in the concentration range of 10&ndash, 400 &mu, g/mL in cervix ephitelial tumor cells. Similarly, hederagenin presented antiproliferative activity at concentrations between 25&ndash, g/mL. In turn, hederacoside C was shown to be noncytotoxic in normal fibroblasts and cervix ephitelial tumor cell culture at all the tested concentrations. The obtained experimental results were analyzed by &ldquo, Mixture design&rdquo, a specialized form of the response surface method (RSM) provided by the Design Expert 11 software, and the optimal composition of obtained saponins mixture was selected and verified in vitro for antiproliferative activity. The results showed that an optimal saponins mixture has the potential to be used in pharmacological applications.