Curcumin‐loaded collagen cryostructurates have been devised for wound healing applications. Curcumin displays strong antioxidant, antiseptic, and anti‐inflammatory properties, while collagen is ...acknowledged for promoting cell adhesion, migration and differentiation. However, when curcumin is loaded directly into collagen hydrogels, it forms large molecular aggregates and clogs the matrix pores. A double‐encapsulation strategy is therefore developed by loading curcumin into lipid nanoparticles (LNP), and embedding these particles inside collagen scaffolds. The resulting collagen/LNP cryostructurates have an optimal fibrous structure with ≈100 µm average pore size for sustaining cell migration. Results show that collagen is structurally unaltered and that nanoparticles are homogeneously distributed amidst collagen fibers. Hydrogels soaked in saline buffer release about 20 to 30% of their nanoparticles content within 24 h, while achieved 100% release after 25 days. When exposed to NIH 3T3 fibroblasts, these hydrogels provide a satisfactory scaffold for cell interaction as early as 4 h after seeding, with no cytotoxic counter effect. These positive features make the collagen/lipid cryostructurates a promising material for further use in wound healing.
Curcumin‐loaded lipid nanoparticles (LNP) are encapsulated into collagen cryostructurates to design innovative wound‐healing materials. The collagen/LNP scaffolds are characterized by different techniques (scanning electron microscopy, transmission electron microscopy, atomic force microscopy, differential scanning calorimetry, and compression) to assess their structural and mechanical properties. They display good adhesion properties with both keratinocytes and fibroblasts, and double‐encapsulation strategy prolongs curcumin payload release.
The microbiome plays an important role in lipid metabolism but how the introduction of probiotic communities affects host lipid metabolism is poorly understood. Using a multidisciplinary approach we ...addressed this knowledge gap using the zebrafish model by coupling high-throughput sequencing with biochemical, molecular and morphological analysis to evaluate the changes in the intestine. Analysis of bacterial 16S libraries revealed that Lactobacillus rhamnosus was able to modulate the gut microbiome of zebrafish larvae, elevating the abundance of Firmicutes sequences and reducing the abundance of Actinobacteria. The gut microbiome changes modulated host lipid processing by inducing transcriptional down-regulation of genes involved in cholesterol and triglycerides metabolism (fit2, agpat4, dgat2, mgll, hnf4α, scap, and cck) concomitantly decreasing total body cholesterol and triglyceride content and increasing fatty acid levels. L. rhamnosus treatment also increased microvilli and enterocyte lengths and decreased lipid droplet size in the intestinal epithelium. These changes resulted in elevated zebrafish larval growth. This integrated system investigation demonstrates probiotic modulation of the gut microbiome, highlights a novel gene network involved in lipid metabolism, provides an insight into how the microbiome regulates molecules involved in lipid metabolism, and reveals a new potential role for L. rhamnosus in the treatment of lipid disorders.
Nanomaterials in agriculture represent one of the most innovative method for protecting crops, due to possibility of being applied as nanopesticides or nanocarriers for active ingredients. ...Furthermore, nanotechnology could be combined with the concept of circular economy through the opportunity of obtaining highly technological nanometric materials starting from agro-industrial wastes. The present research evaluated the possibility of synthesizing cellulose nanocrystals (CNCs) from olive pruning wastes through chemical bleaching, reusing them as sustainable tool to control the causal agent of the olive knot disease (Pseudomonas savastanoi pv. savastanoi). CNCs showed an interesting in vitro effect in inhibiting bacterial growth and bacterial biofilm formation, as well as the ability of reducing bacterial epiphytic survival in a comparable way to copper sulphate on leaf surfaces, when used at 1% w/v. CNCs were at the same time investigated for their interaction with olive tree seedlings, showing no negative effects on leaf development, and a promising root uptake, indicating that CNCs could be used also as nanocarriers for active ingredients. Obtained results highlight the innovative possibility of designing sustainable plant protection strategies capable of revalorise lignocellulosic wastes, meaning a simultaneous low environmental impact thanks to reduction of traditional agrochemicals input.
Saffron is the dried stigmas of Crocus sativus and is the most expensive spice in the world. Its red color is due to crocins, which are apocarotenoid glycosides that accumulate in the vacuole to a ...level up to 10% of the stigma dry weight. Previously, we characterized the first dedicated enzyme in the crocin biosynthetic pathway, carotenoid cleavage dioxygenase2 (CsCCD2), which cleaves zeaxanthin to yield crocetin dialdehyde. In this work, we identified six putative aldehyde dehydrogenase (ALDH) genes expressed in C. sativus stigmas. Heterologous expression in Escherichia coli showed that only one of corresponding proteins (CsALDH3I1) was able to convert crocetin dialdehyde into the crocin precursor crocetin. CsALDH3I1 carries a carboxyl-terminal hydrophobic domain, similar to that of the Neurospora crassa membrane-associated apocarotenoid dehydrogenase YLO-1. We also characterized the UDP-glycosyltransferase CsUGT74AD1, which converts crocetin to crocins 1 and 2′. In vitro assays revealed high specificity of CsALDH3I1 for crocetin dialdehyde and long-chain apocarotenals and of CsUGT74AD1 for crocetin. Following extract fractionation, CsCCD2, CsALDH3I1, and CsUGT74AD1 were found in the insoluble fraction, suggesting their association with membranes or large insoluble complexes. Analysis of protein localization in both C. sativus stigmas and following transgene expression in Nicotiana benthamiana leaves revealed that CsCCD2, CsALDH3I, and CsUGT74AD1 were localized to the plastids, the endoplasmic reticulum, and the cytoplasm, respectively, in association with cytoskeleton-like structures. Based on these findings and current literature, we propose that the endoplasmic reticulum and cytoplasm function as transit centers for metabolites whose biosynthesis starts in the plastid and are accumulated in the vacuole.
Neisseria gonorrhoeae is an exclusively human pathogen able to evade the host immune system through multiple mechanisms. Gonococci accumulate a large portion of phosphate moieties as polyphosphate ...(polyP) on the exterior of the cell. Although its polyanionic nature has suggested that it may form a protective shield on the cell surface, its role remains controversial. Taking advantage of a recombinant His-tagged polyP-binding protein, the presence of a polyP pseudo-capsule in gonococcus was demonstrated. Interestingly, the polyP pseudo-capsule was found to be present in specific strains only. To investigate its putative role in host immune evasion mechanisms, such as resistance to serum bactericidal activity, antimicrobial peptides and phagocytosis, the enzymes involved in polyP metabolism were genetically deleted, generating mutants with altered polyP external content. The mutants with lower polyP content on their surface compared to the wild-type strains, became sensitive to complement-mediated killing in presence of normal human serum. Conversely, naturally serum sensitive strains that did not display a significant polyP pseudo-capsule became resistant to complement in the presence of exogenous polyP. The presence of polyP pseudo-capsule was also critical in the protection from antibacterial activity of cationic antimicrobial peptide, such as cathelicidin LL-37. Results showed that the minimum bactericidal concentration was lower in strains lacking polyP than in those harboring the pseudo-capsule. Data referring to phagocytic killing resistance, assessed by using neutrophil-like cells, showed a significant decrease in viability of mutants lacking polyP on their cell surface in comparison to the wild-type strain. The addition of exogenous polyP overturned the killing phenotype of sensitive strains suggesting that gonococcus could exploit environmental polyP to survive to complement-mediated, cathelicidin and intracellular killing. Taken together, data presented here indicate an essential role of the polyP pseudo-capsule in the gonococcal pathogenesis, opening new perspective on gonococcal biology and more effective treatments.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The antitumor activity of polyphenols derived from extra virgin olive oil and, in particular the biological activity of HTyr, has been studied extensively. However, the use of HTyr as a therapeutic ...agent for clinical applications is limited by its low bioavailability and rapid excretion in humans. To overcome these limitations, several synthetic strategies have been optimized to prepare lipophenols and new compounds derived from HTyr to increase lipophilicity and bioavailability. One very promising ester is hydroxytyrosyl oleate (HTyr-OL) because the chemical structure of HTyr, which is responsible for several biological activities, is linked to the monounsaturated chain of oleic acid (OA), giving the compound high lipophilicity and thus bioavailability in the cellular environment. In this study, the in vitro cytotoxic, anti-proliferative, and apoptotic induction activities of HTyr-OL were evaluated against SH-SY5Y human neuroblastoma cells, and the effects were compared with those of HTyr and OA. The results showed that the biological activity of HTyr was maintained in HTyr-OL treatments at lower dosages. In addition, the shotgun proteomic approach was used to study HTyr-OL-treated and untreated neuroblastoma cells, revealing that the antioxidant, anti-proliferative and anti-inflammatory activities of HTyr-OL were observed in the unique proteins of the two groups of samples.
Achieving prolonged and localized delivery of small interfering RNA (siRNA) at a specific site is highly desirable, since siRNA therapy has become a promising strategy for many medical applications. ...Many different synthetic or natural biomaterials have been studied for local sustained drug delivery. Of those, collagen has received increased attention, especially for wound applications, due to its biocompatibility, safety, and hemostatic properties. Therefore, we here investigated freeze-dried collagen scaffolds as localized siRNA delivery systems. Because siRNA faces significant difficulty in crossing biological membranes, efficient nanocarriers have been fabricated from synthetic or natural materials, such as chitosan (CS) and nanostructured lipid carriers (NLC). Collagen scaffolds were loaded with either naked siRNA or NLC/siRNA complexes, formed with cationic NLC comprising either a chitosan coating (CS-NLC), or DOTAP (1,2-dioleoyl-3-trimethylammonium-propan) and DOPE (1,2-Dioleoyl-sn-glycero-3-phosphoethanolamine) shell (cNLC). siRNA or NLC/siRNA loading did not affect collagen scaffold properties (structure and swelling ratio). Collagen loaded with cNLC nanoparticles achieved the most prolonged siRNA release and in vitro downregulation of ERK-1 protein (at least 7 days), which is involved in proliferation and wound healing. In conclusion, lipid nanoparticle templates were useful in prolonging and promoting siRNA delivery from collagen scaffolds.
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Recent scientific investigations have reported a number of essential oils to interfere with intracellular signalling pathways and to induce apoptosis in different cancer cell types. In this paper, ...Lavandin Essential Oil (LEO), a natural sterile hybrid obtained by cross-breeding
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was tested on human leukaemia cells (HL60). Based on the MTT results, the reduced cell viability of HL60 cells was further investigated to determine whether cell death was related to the apoptotic process. HL60 cells treated for 24 h with LEO were processed by flow cytometry, and the presence of Annexin V was measured. The activation of caspases-3 was evaluated by western blot and immunofluorescence techniques. Treated cells were also examined by scanning and transmission electron microscopy to establish the possible occurrence of morphological alterations during the apoptotic process. LEO main compounds, such as linalool, linalyl acetate, 1,8-cineole, and terpinen-4-ol, were also investigated by MTT and flow cytometry analysis. The set of obtained results showed that LEO treatments induced apoptosis in a dose-dependent, but not time-dependent, manner on HL60 cells, while among LEO main compounds, both terpinen-4-ol and linalyl acetate were able to induce apoptosis.
The vast use of silver nanoparticles (AgNPs) mandates thorough investigation of their impact on biosystems at various levels. The cytotoxicity of PVP coated-AgNPs to pollen, the aploid male ...gametophyte of higher plants, has been assessed here for the first time. The negative effects of AgNPs include substantial decreases in pollen viability and performance, specific ultrastructural alterations, early changes in calcium content, and unbalance of redox status. Ag+ released from AgNPs damaged pollen membranes and inhibited germination to a greater extent than the AgNPs themselves. By contrast, the AgNPs were more potent at disrupting the tube elongation process. ROS deficiency and overproduction were registered in the Ag+- and AgNP-treatment, respectively. The peculiar features of AgNP toxicity reflected their specific modes of interaction with pollen surface and membranes, and the dynamic exchange between coating (PVP) and culture medium. In contrast, the effects of Ag+ were most likely induced through chemical/physicochemical interactions.
•Kiwifruit pollen was treated with 10 nm-sized PVP-coated AgNPs.•Pollen lethality increased with increasing either nanosized or ionic silver dose.•At the ultrastructural level, AgNP-specific alteration of plasmalemma appeared.•Pollen tube emergence and elongation were differently sensitive to AgNPs and Ag+.•In the pollen model, the biological potency of AgNPs did not match that of Ag+.
AgNP toxicity to pollen does not match the effects of released Ag+.
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