•Polysaccharide-based films can enhance physicochemical features of coated material.•SEM and XPS analysis confirmed presence of the coating on bioactive glass scaffolds.•Scaffold coated with Chi/CS ...influenced on hydroxyapatite formation.•Effect of carboxylic groups in bioactivity test was pointed for coated scaffolds.
Bioactive glasses are crucial in regenerative medicine, meeting the demand for biomaterial–bone tissue integration. This study explores the effect of polymer-based films on bioactive glass, evaluating their impact on biological and physicochemical properties to potentially improve cell-material interaction. Polysaccharide-based films were used to modify a silica-based bioactive glass, analyzing surface features, composition, and bioactivity upon immersion in simulated body fluid. Surface characteristics investigation confirmed successful functionalization, but no notable differences were found in bioactivity between unmodified and polymer-coated materials. Therefore, the polymer-based coating is not detrimental for the scaffold’s apatite-forming ability, and is expected to facilitate bone cell attachment, which deserves future investigation.
The bioactive glass (BG) system of 60SiO2–4P2O5–31CaO-xSrO-(5-x) ZnO (0 ≤ x ≤ 5 %mol) was synthesized by sol-gel route. The role of zinc contents and strontium on the in-vitro formation of ...hydroxyapatite (HA), antibacterial properties, and cell viability of BGs were investigated. XRD (X-ray diffraction analysis), SEM (Scanning electron microscopy) and FTIR (Fourier transform infrared spectroscopy) were utilized to study the HA morphology, its functional groups and obtained phases, respectively. The results established the formation of HA on the surface of strontium and zinc-containing BGs. The 3-(4,5 dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay after one day immersion in SBF, implied that the viability of samples containing 4 %mol Sr and 1 %mol Zn (S4-Z1) and 3 %mol Sr and 2 %mol Zn (S3-Z2) increases by increasing immersion time, while the sample containing 1 %mol Sr and 4 %mol Zn (S1-Z4) showed a statistically significant increase in osteoblast G292 proliferation. Furthermore, the antibacterial tests showed that all Zn containing BGs created clear inhabitation zones. The zone of clearance around the bioactive glasses demonstrated that sufficient Zn ion was released to create an antibacterial activity around the bioactive glasses.
Ursolic acid (UA), which has many biological properties such as anti-cancer, anti-inflammatory and antioxidant, and regulates some pharmacological processes, has been isolated from the flowers, ...leaves, berries and fruits of many plant species. In this work, UA was purified from the methanol-chloroform crude extract of Nepeta species (N. aristata, N. baytopii, N. italica, N. trachonitica, N. stenantha) using a silica gel column with chloroform or ethyl acetate solvents via bioactivity-guided isolation. The most active sub-fractions were determined under bioactivities using antioxidant and DNA protection activities and enzyme inhibitions. UA was purified from these fractions and its structure was elucidated by NMR spectroscopy techniques. The highest amount of UA was found in N. stenantha (8.53 mg UA/g), while the lowest amount of UA was found in N. trachonitica (1.92 mg UA/g). The bioactivities of UA were evaluated with antioxidant and DNA protection activities, enzyme inhibitions, kinetics and interactions. The inhibition values (IC
50
) of α-amylase, α-glucosidase, urease, CA, tyrosinase, lipase, AChE, and BChE were determined between 5.08 and 181.96 µM. In contrast, K
i
values of enzyme inhibition kinetics were observed between 0.04 and 0.20 mM. In addition, K
i
values of these enzymes for enzyme-UA interactions were calculated as 0.38, 0.86, 0.45, 1.01, 0.23, 0.41, 0.01 and 2.24 µM, respectively. It is supported that UA can be widely used as a good antioxidant against oxidative damage, an effective DNA protector against genetic diseases, and a suitable inhibitor for metabolizing enzymes.
Communicated by Ramaswamy H. Sarma
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•Chitosan coatings containing ZnO particle were deposited on porous Ti oxide.•Chitosan/ZnO coating had a higher ability to inhibit E. coli adhesion than chitosan.•Chitosan/ZnO ...exhibited a higher bioactivity due to Zn2+ ion release.•Adhesive strength of coating increased with the amount of ZnO in the coatings.•Chitosan/ZnO coatings improved the corrosion resistance of Ti in solution.
A biocomposite coating comprising chitosan and ZnO deposited on a porous Ti oxide is developed to avoid orthopedic and dental implant-related infections. The coating comprised of an inner layer of nanoporous TiO2 and the outer layer of the chitosan matrix with ZnO nanoparticles. Microbiological tests show that chitosan coating is effective against Escherichia coli (E. coli), however, its ability to inhibit bacterial adhesion is very limited. A 1.2-fold increase in the antibacterial activity of chitosan/ZnO coating against E. coli was detected as compared to the chitosan coating alone, and the chitosan/ZnO efficiently inhibited biofilm formation. In addition, the chitosan/ZnO coating exhibited improved bioactivity compared to the chitosan coating. The improvement in antibacterial properties and bioactivity of the chitosan/ZnO coating is attributed to the release of Zn2+ ions. The critical force of scratching the chitosan/ZnO coating was approximately twice that of the chitosan coating. The potentiodynamic polarization results confirmed that the corrosion resistance of the implant with ZnO/chitosan/Ti structure was improved. In addition, cytocompatibility evaluation indicated that the chitosan/ZnO coating has good cytocompatibility in MG-63 cells as compared to pure Ti.
Drop-on-demand (DoD) micro dispensing technique, which enabled nano apatite crystals including hydroxyapatite (HA), silicon-substituted HA (SiHA), silver-substituted HA (AgHA) droplets to be ...deposited on glass substrate with precise placement, size, and number of droplets was presented in this work. Multi-material coatings containing SiHA:AgHA = 1:3 (1SiHA-3AgHA) were fabricated for obtaining favourable bioactivity and enhanced antibacterial properties. The antibacterial effect of 1SiHA-3AgHA towards Escherichia coli (E. coli) indicated a delayed exponential growth for up to 24 h, with significantly less bacteria adhesion compared to HA and SiHA coatings. The biological response of adipose-derived mesenchymal stem cells (hASCs) cultured on 1SiHA-3AgHA coatings exhibited enhanced cell attachment, proliferation and differentiation, as compared to HA and AgHA coatings. Hence, DoD micro deposition technique could be potentially used in producing multi-material coatings for biomedical applications.
The importance of nitriles as a key class of chemicals with applications across the sciences is widely appreciated. The natural world is an underappreciated source of chemically diverse nitriles. ...With this in mind, this review describes novel nitrile-containing molecules isolated from natural sources from 1998 to 2021, as well as a discussion of the biological activity of these compounds. This study gathers 192 molecules from varied origins across the plant, animal, and microbial worlds. Their biological activity is extremely diverse, with many potential medicinal applications.
Most of the traditional strategies used for facing the management of insect pest and diseases have started to fail due to different toxicological issues such as the resistance of target organism and ...the impact on environment and human health. This has made mandatory to seek new effective strategies, which minimize the risks and hazards without compromising the effectiveness of the products. The use of essential oils, their components and semiochemicals (pheromones and allelochemicals) has become a promising safe and eco-sustainable alternative for controlling insect pest and pathogens. However, the practical applications of this type of molecules remain rather limited because their high volatility, poor solubility in water and low chemical stability. Therefore, it is required to design strategies enabling their use without any alteration of their biological and chemical properties. Oil-in-water nano/microemulsions are currently considered as promising tools for taking advantage of the bioactivity of essential oils and their components against insects and other pathogens. Furthermore, these colloidal systems also allows the encapsulation and controlled release of semiochemicals, which enables their use in traps for monitoring, trapping or mating disruption of insects, and in push-pull strategies for their behavioral manipulation. This has been possible because the use of nano/microemulsions allows combining the protection provided by the hydrophobic environment created within the droplets with the enhanced dispersion of the molecules in an aqueous environment, which favors the handling of the bioactive molecules, and limits their degradation, without any detrimental effect over their biological activity. This review analyzes some of the most recent advances on the use of emulsion-like dispersions as a tool for controlling insect pest and pathogens. It is worth noting that even though the current physico-chemical knowledge about these systems is relatively poor, a deeper study of the physico-chemical aspects of nanoemulsions/microemulsions containing essential oils, their components or semiochemicals, may help for developing most effective formulations, enabling the generalization of their use.
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•Essential oils (EOs), their components (EOCs) or semiochemicals (SE) are allows controlling insect pests and pathogens.•Instability and volatility of EOs, EOCs or SEs require of strategies for taking advantage of their biological activity.•Micro-/nanoemulsions are good tools for design formulations with EOs, EOCs or SEs.•EOs, EOCs or SEs contained within emulsion-like systems commonly present higher biological activity that their free form.•Physico-chemical and operative parameter are essential in the characteristics of the micro−/nanoemulsions.
Chitosan hydrogel is a smart and highly applicable drug delivery carrier because of its nature, biocompatibility, biodegradability, and ability to encapsulate, carry and release the drug to the ...desired target flexibly depending on the conditions of the patient. Not only developing delivery systems but natural compounds are also increasingly being studied in supporting the treatment of diseases. However, the physicochemical and pharmacokinetic issues of the phytochemicals are remaining. This review summarizes the remarkable properties of chitosan hydrogel; approaches to loading natural extracts on the hydrogels to overcome the susceptibility of the phytochemicals to degradation; and their applications in biomedical fields. The drug loading efficiency, release profile, in vitro and in vivo results of the chitosan hydrogels carrying natural compounds are discussed to point out the remaining challenges of combining the extracts with chitosan hydrogels and controlling the release of the carried substances.
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