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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.

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.

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.

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.

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.