Biomineralization of superhydrophilic vertically aligned carbon nanotubes.

Vertically aligned carbon nanotubes (VACNT) promise a great role for the study of tissue regeneration. In this paper, we introduce a new biomimetic mineralization routine employing superhydrophilic VACNT films as highly stable template materials. The biomineralization was obtained after VACNT soaking in simulated body fluid solution. Detailed structural analysis reveals that the polycrystalline biological apatites formed due to the -COOH terminations attached to VACNT tips after oxygen plasma etching. Our approach not only provides a novel route for nanostructured materials, but also suggests that COOH termination sites can play a significant role in biomimetic mineralization. These new nanocomposites are very promising as nanobiomaterials due to the excellent human osteoblast adhesion.

Prolonged Drug-Releasing Fibers Attenuate Alzheimer's Disease-like Pathogenesis.

Delivering drugs and agents to the brain is a huge challenge, especially for chronic neurodegenerative disorders, such as Alzheimer's disease (AD). For this, prolonged and sustained release methods to increase brain uptake represent an impacting concept. The bioresorbable polymer poly-lactic acid (PLA) has high potential for medical implants; at the same time, glucagon-like peptide-1 (GLP-1) analogues have considerable neuroprotective attributes and represent a therapeutic strategy for AD. Here, a biodevice is produced by electrospinning PLA with a GLP-1 analogue (liraglutide, LG), coated with a thin layer of gelatin. The biodevice is subcutaneously implanted in a transgenic mouse model of AD and LG is released for 14 days in mice serum. After 4 weeks of implantation, crucial hallmarks of the AD are highly diminished: hippocampal senile amyloid ß plaque load and neuroinflammatory markers. Furthermore, neurogenesis is enhanced in the subventricular zone, an important neurogenic niche in the brain. The designed biodevice holds great promise for being an affordable candidate to act as a prolonged drug provider, promoting LG mission through increasing its lifetime, constituting a relevant approach for old and impaired brain.

A Novel Bioresorbable Device as a Controlled Release System for Protecting Cells from Oxidative Stress from Alzheimer's Disease.

Bioresorbable electrospun fibres have highly functional features that can preserve drug efficacy, avoiding premature degradation, and control drug release rates over long periods. In parallel, it is known that Alzheimer's disease (AD) has been linked to impaired insulin signalling in the brain. Glucagon-like peptide 1 (GLP-1) analogues have beneficial effects on insulin release and possess exceptional neuroprotective properties. Herein, we describe for the first time the incorporation of a GLP-1 analogue, liraglutide, into electrospun poly (lactic acid) (PLA) fibres with in situ gelatin capsules, in order to provide the controlled release of liraglutide, improving neuroprotective properties. In this study, PLA, a bioresorbable polymer in which degradation products have neurogenesis characteristics, was electrospun and loaded with liraglutide. Moreover, PLA/liraglutide fibres were encapsulated with gelatin and were shown to have better properties than the non-encapsulated fibres in terms of the controlled release of liraglutide, which was accomplished in the present study for up to 60 days. We observed that this biodevice was completely encapsulated with gelatin, which made the material more hydrophilic than PLA fibres alone and the biodevice was able to enhance fibroblast interaction and reduce mitochondrial stress in a neuroblastoma cell line. In this manner, this study introduces a new material which can improve neuroprotective properties from AD oxidative stress via the sustained long-lasting release of liraglutide. Graphical Abstract ᅟ.

Biological activities of Rosmarinus officinalis L. (rosemary) extract as analyzed in microorganisms and cells.

R. officinalis L. is an aromatic plant commonly used as condiment and for medicinal purposes. Biological activities of its extract were evaluated in this study, as antimicrobial effect on mono- and polymicrobial biofilms, cytotoxicity, anti-inflammatory capacity, and genotoxicity. Monomicrobial biofilms of Candida albicans, Staphylococcus aureus, Enterococcus faecalis, Streptococcus mutans and Pseudomonas aeruginosa and polymicrobial biofilms composed of C. albicans with each bacterium were formed in microplates during 48 h and exposed for 5 min to R. officinalis L. extract (200 mg/mL). Its cytotoxic effect was examined on murine macrophages (RAW 264.7), human gingival fibroblasts (FMM-1), human breast carcinoma cells (MCF-7), and cervical carcinoma cells (HeLa) after exposure to different concentrations of the extract, analyzed by MTT, neutral red (NR), and crystal violet (CV) assays. The anti-inflammatory activity was evaluated on RAW 264.7 non-stimulated or stimulated by lipopolysaccharide (LPS) from Escherichia coli and treated with different concentrations of the extract for 24 h. Interleukin-1 beta (IL-1ß) and tumor necrosis factor alpha (TNF-α) were quantified by ELISA. Genotoxicity was verified by the frequency of micronuclei (MN) at 1000 cells after exposure to concentrations of the extract for 24 h. Data were analyzed by T-Test or ANOVA and Tukey Test ( P ≤ 0.05). Thus, significant reductions in colony forming units per milliliter (CFU/mL) were observed in all biofilms. Regarding the cells, it was observed that concentrations ≤ 50 mg/mL provided cell viability of above 50%. Production of proinflammatory cytokines in the treated groups was similar or lower compared to the control group. The MN frequency in the groups exposed to extract was similar or less than the untreated group. It was shown that R. officinalis L. extract was effective on mono- and polymicrobial biofilms; it also provided cell viability of above 50% (at ≤ 50 mg/mL), showed anti-inflammatory effect, and was not genotoxic. Impact statement Rosmarinus officinalis L. extract effectively contributed to in vitro control of important species of microorganisms such as Candida albicans, Staphylococcus aureus, Enterococcus faecalis, Streptococcus mutans, and Pseudomonas aeruginosa in mono- and polymicrobial biofilms that are responsible for several infections in oral cavity as in other regions of the body. Furthermore, this extract promoted also cell viability above 50% at concentrations ≤ 50 mg/mL, excellent anti-inflammatory effect, showing inhibition or reduction of the synthesis of proinflammatory cytokines, being also non-genotoxic to cell lines studied. Thus, this extract may be a promising therapeutic agent that can be added in some medical and dental formulations such as toothpastes, mouthwashes, irrigating root canals, ointments, soaps, in order to control pathogenic microorganisms and biofilms, with anti-inflammatory effect and absence of cytotoxic and genotoxic.

Dental enamel irradiated with infrared diode laser and photoabsorbing cream: Part 1 -- FT-Raman Study.

OBJECTIVE: The aim of this FT-Raman study was to investigate laser-induced compositional changes in enamel after therapy with a low-level infrared diode laser and a photoabsorbing cream, in order to intensify the superficial light absorption before and after cariogenic challenge. BACKGROUND DATA: Dental caries remains the most prevalent disease during childhood and adolescence. Preventive modalities include the use of fluoride, reduction of dietary cariogenic refined carbohydrates, plaque removal and oral hygiene techniques, and antimicrobial prescriptions. A relatively simple and noninvasive caries preventive regimen is treating tooth enamel with laser irradiation, either alone or in combination with topical fluoride treatment, resulting in reduced enamel solubility and dissolution rates. Due to their high cost, high-powered lasers are still not widely employed in private practice in developing countries. Thus, low-power red and near-infrared lasers appear to be an appealing alternative. MATERIALS AND METHODS: Twenty-four extracted or exfoliated caries-free deciduous molars were divided into six groups: control group (no treatment; n = 8); infrared laser treatment (L; n = 8) (810 nm at 100 mW/cm(2) for 90 sec); infrared diode laser irradiation (810 nm at 100 mW/cm(2) for 90 sec) and photoabsorbing cream (IVL; n = 8); photoabsorbing cream alone (IV; n = 8); infrared diode laser irradiation (810 nm at 100 mW/cm(2) for 90 sec) and fluorinated photoabsorbing agent (IVLF; n = 8); and fluorinated photoabsorbing agent alone (IVF; n = 8). Samples were analyzed using FT-Raman spectroscopy before and after pH cycling cariogenic challenge. RESULTS: There was a significant laser-induced reduction and possible modification of the organic matrix content in enamel treated with the low-level diode laser (the L, IVL, and IVFL groups). CONCLUSION: The FT-Raman technique may be suitable for detecting compositional and structural changes occurring in mineral phases and organic phases of lased enamel under cariogenic challenge.

Dental enamel irradiated with infrared diode laser and photo-absorbing cream: part 2--EDX study.

OBJECTIVE: The effects of laser-induced compositional changes on the enamel were investigated by energy-dispersive X-ray fluorescence spectrometry (micro-EDX). After cariogenic challenge, we administered treatment of low-level infrared diode laser and a photo-absorbing cream (used to intensify the superficial light absorption). BACKGROUND DATA: Dental caries is considered the most prevalent oral disease. A simple and noninvasive caries preventive regimen is treating tooth enamel with a laser, either alone or in combination with fluoride, which reduces enamel solubility and dissolution rates. High power lasers are still not widely used in private practice. Low-power near-infrared lasers may be an alternative approach. Energy-dispersive micro-EDX is a versatile and nondestructive spectroscopic technique that allows for a qualitative and quantitative elemental analysis of inorganic enamel components, such as calcium and phosphorus. MATERIALS AND METHODS: Twenty-four extracted or exfoliated caries-free deciduous molars were divided into six groups: 1) control group (CTR-no treatment); 2) infrared laser treatment (L) (lambda = 810 nm, 100 mW/cm(2), 90 sec, 4.47 J/cm(2), 9 J); 3) infrared laser irradiation and photo-absorbing agent (CL); 4) photo-absorbing agent alone (C); 5) infrared laser irradiation and fluoridated photo-absorbing agent (FCL); and 6) fluoridated photo-absorbing agent alone (FC). Samples were analyzed using micro-EDX after two sets of treatments and pH cycling cariogenic challenges. RESULTS: The CL group showed statistically significant increases in calcium and phosphorus (wt%) compared with the CTR group. The Ca/P ratio was similar in the FCL and CTR groups. There was a significant laser-induced reduction compared with the CTR group, and there was a possible modification of the organic balance content in enamel treated with laser and cream. CONCLUSION: micro-EDX may be able to detect compositional changes in mineral phases of lased enamel under cariogenic challenge. Our results suggest that with a combined laser and photo-absorbing agent (CL) treatment, there was a possible disorganization of organic content in the tooth enamel with hydroxyapatite crystal reordering and reorganization.