Search

With the objective of creating an electro‐responsive and antimicrobial device suitable as delivery system for Rose Bengal (RB) to the skin, a hybrid hydrogel combining Chitosan (CS) and Graphene Oxide (GO) are designed, serving as functional polymer support and active filling element, respectively. The hybrid system, synthesized using tripolyphosphate as a crosslinker via ionic gelation, shows a uniform and homogeneous surface, as verified by SEM investigations, high biocompatibility when tested on human fibroblast lung cells MRC‐5 cells, and biodegradability in phosphate buffered medium at physiological pH. Drug loading and release experiments, extensively analyzed using suitable mathematical modeling, shows the enhancement of the binding efficiency conferred by GO (534 and 979 mg g−1 for blank and hybrid hydrogels, respectively) and an electro‐responsive behavior (maximum BR release of 36 and 23% at 0 and 12 V, respectively). Additionally, hybrid hydrogel is found to prevent the adhesion of methicillin‐resistant Staphylococcus aureus and to kill the bacterial cells by taking advantage of the sustained release of the antimicrobial RB. [ABSTRACT FROM AUTHOR]

Hybrid hydrogel films able to modulate the release of anionic species, ketoprofen (Ket) and bovine serum albumin (BSA), as a function of their molecular size are prepared by UV-induced polymerization of methacrylated gelatin in the presence of oxidized multiwalled carbon nanotubes (MWNT_COOH). The dual-stimuli responsive composites can modulate the release in response to the variation of temperature and the application of an external voltage. Drug release profiles, analyzed by mathematical models, show that different temperatures (25 and 45 °C) and applied voltages (0 and 36 V) have a different effect on the release of the two therapeutics. Ket release is enhanced at 45 °C (77% vs 22% at 25 °C) with the maximum value recorded when 36 V is applied (94%). An increase in the amount of released BSA is recorded at 45 °C (96% vs 50% at 25 °C), while the application of the external voltage reduces this value (39%). [ABSTRACT FROM AUTHOR]

Dextran-catechin conjugate with high functionalization degree is synthesized by using a fully green process based on the chemistry of laccase immobilized on hydrogel film. By UV-induced radical polymerization, the enzyme is immobilized into acrylate hydrogel film resulting in a highly performing biocatalyst (residual catalytic activity of 60% upon immobilization). ¹H-NMR studies of dextran-catechin conjugate allow the elucidation of the reaction mechanism and the assessment of the functionalization degree (128 mg of catechin per gram of conjugate). Cell viability studies performed in neuroblastoma cells clearly prove the anticancer potential of the conjugate (IC50 value of 17.03 µg mL-1) while being well tolerated by nonmalignant cells. The efficiency of this conjugate is found to be similar to dextran-catechin, previously prepared by free radical reaction. This novel green approach of synthesis for dextran-catechin opens new perspectives for the environmentally sustainable development of novel natural derived drugs to treat neuroblastoma and other cancers. [ABSTRACT FROM AUTHOR]

Many tumors including prostate cancer are maintained by cancer stem cells (CSCs), which might cause tumor relapse if not eradicated during the course of treatment. Specific targeting or radiosensitization of CSCs bear promise to improve tumor curability by synergistic effects in combination with radiotherapy. Carbon nanotubes (CNTs) can be used as promising drug delivery systems for anticancer drugs such as the flavonoid catechin. Catechin is an extensively studied active ingredient of the different plants, including green tea, and it is widely recognized as co-adjuvant in cancer therapy. Here we describe the synthesis of biocompatible, catechin-loaded and gelatin-conjugated CNTs (Gel_CT_CNTs) with anticancer properties and demonstrate their potential for the eradication of prostate CSCs in combination with X-ray irradiation. Gel_CT_CNTs showed a significant enhancement of in vitro anticancer activity as compared to catechin alone. Moreover, treatment of prostate cancer cells with Gel_CT_CNT nanohybrids inhibited the tumorigenic cell population defined by a high aldehyde dehydrogenase (ALDH) activity. A combination of X-ray irradiation and treatment with Gel_CT_CNTs caused a decrease in the protein level of stem cell-related transcription factors and regulators including Nanog, Oct4 and β-catenin and led to an increase of cancer cell radiosensitivity as demonstrated by clonogenic and spherogenic cell survival assays. Taken together, our results suggest that a combination of irradiation and Gel_CT_CNTs can be potentially used for the radiosensitization and eradication of prostate CSC populations. [ABSTRACT FROM AUTHOR]

Background: Periodontitis is a complex multifactorial disease and is typically polygenic in origin. Genes play a fundamental part in each biologic process forming complex networks of interactions. However, only some genes have a high number of interactions with other genes in the network and may, therefore, be considered to play an important role. In a preliminary bioinformatic analysis, five genes that showed a higher number of interactions were identified and termed leader genes. In the present study, we use real-time quantitative polymerase chain reaction (PCR) technology to evaluate the expression levels of leader genes in the leukocytes of 10 patients with refractory chronic periodontitis and compare the expression levels with those of the same genes in 24 healthy patients. Methods: Blood was collected from 24 healthy human subjects and 10 patients with refractory chronic periodontitis and placed into heparinized blood collection tubes by personnel trained in phlebotomy using a sterile technique. Blood leukocyte cells were immediately lysed by using a kit for total RNA purification from human whole blood. Complementary DNA (cDNA) synthesis was obtained from total RNA and then real-time quantitative PCR was performed. PCR efficiencies were calculated with a relative standard curve derived from a five cDNA dilution series in triplicate that gave regression coefficients >0.98 and efficiencies >96%. The standard curves were obtained using glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and growth factor receptor binding protein 2 (GRB2), casitas B-lineage lymphoma (CBL), nuclear factor-KB1 (NFKB1), and REL-A (gene for transcription factor p65) gene primers and amplified with 1.6, 8, 40 200, and 1,000 ng/µL total cDNA. Curves obtained for each sample showed a linear relationship between RNA concentrations and the cycle threshold value of real-time quantitative PCR for all genes. Data were expressed as mean ± SE (SEM). The groups were compared to the analysis of variance. A probability value <0.01 was considered statistically significant. Results: The present study agrees with the preliminary bioinformatics analysis. In our experiments, the association of pathology with the genes was statistically significant for GRB2 and CBL (P <0.01), and it was not statistically significant for REL-A and NFKB1. Conclusion: This article lends support to our preliminary hypothesis that assigned an important role in refractory aggressive periodontitis to leader genes. [ABSTRACT FROM AUTHOR]

Multifunctional hydrogels based on chitosan–quercetin (CHITQ) conjugate are prepared by a thermo‐induced radical procedure in the presence of N‐isopropylacrylamide (NIPAAm), acrylamide (AAm), and N,N′‐methylenebis(acrylamide) (MEBA). At first, quercetin (Q) is grafted onto chitosan backbone with a functionalization degree of 275 mg of Q per gram of conjugate, as calculated by 1H‐NMR analyses to impart antioxidant properties to the polysaccharide. Then, a pH and temperature sensitive hydrogel was obtained by involving CHITQ and NIPAAm in the polymerization reaction. The accessibility of phenolic moieties is modified in response to the hydrogel swelling/deswelling, as confirmed by antioxidant tests performed at different temperatures. Dual stimuli‐responsive hydrogels are proposed for the delivery of caffeine as model drug. The release profiles of caffeine depict a system particularly performing as on/off device at acidic pH with excellent applicability prospects. [ABSTRACT FROM AUTHOR]