Platelet-Rich Plasma (PRP) for Sacrococcygeal Pilonidal Disease: An Updated Systematic Review and Meta-Analysis.

BACKGROUND: Pilonidal disease can be a debilitating condition which carries a significant physical and economic burden. This systematic review and updated meta-analysis presents the evidence for the use of platelet-rich plasma (PRP) for wound healing following open and minimally-invasive sacrococcygeal pilonidal surgery. METHODS: A literature search was performed during December 2021 for studies relating to platelet-rich plasma and pilonidal wound healing following surgery. RESULTS: Nine studies remained after applying the exclusion criteria, incorporating a total of 621 (open surgery group) and 309 (minimally-invasive group) patients, respectively. Pooled analysis of the six open surgery group studies demonstrated a significant reduction in wound healing time (mean difference [MD] = - 13.98 days, 95% CI - 18.41 to - 9.55, p < 0.001, I2 = 98%). Three open surgery group studies compared post-operative time off work, while three recorded mean pain duration; pooled analysis also revealed a significant reduction in both outcomes, respectively (MD = - 8.7 days, 95% CI - 9.4 to - 8.0, p < 0.001, I2 = 57%; MD = - 9.5 days, 95% CI - 15.6 to - 3.3, p = 0.002, I2 = 98%). Methodological heterogeneity among the minimally-invasive studies precluded formal meta-analysis; however, two studies demonstrated a modest improvement in wound healing when treated with PRP. CONCLUSIONS: This systematic review and updated meta-analysis provide further evidence supporting the use of PRP for wound healing in sacrococcygeal pilonidal disease. PRP application was demonstrated to significantly reduce healing time, postoperative pain and time off work in the open surgery group. Nevertheless, there is still considerable heterogeneity among PRP manufacture and administration techniques, and further high-powered RCTs with consistent methodology are required to substantiate these findings.

New evidence in one-lung ventilation. / Nueva evidencia en ventilación unipulmonar.

Mechanical ventilation in thoracic surgery has undergone significant changes in recent years due to the implementation of the protective ventilation. This review will analyze recent ventilatory strategies in one-lung ventilation. A MEDLINE research was performed using Mesh term "One-Lung Ventilation" including randomized clinical trials, metanalysis, reviews and systematic reviews published in the last 6 years. Search was performed on 21st March 2017. A total of 75 articles were initially found. After title and abstract review 14 articles were included. Protective ventilation is not simply synonymous of low tidal volume ventilation, but it also includes routine use of PEEP and alveolar recruitment maneuver. New techniques are still in discussion namely PEEP adjustment, ratio inspiration:expiration, ideal type of anesthesia during one-lung ventilation and hypercapnic ventilation.

Coaxial electrospun PCL/Gelatin-MA fibers as scaffolds for vascular tissue engineering.

Coaxial electrospinning is a technique that allows the production of nanofibers with a core-shell structure. Such fibers present several advantages as materials for the preparation of scaffolds, namely due to the possibility of combining a core with the desired mechanical properties with a shell prepared from biocompatible materials that will establish proper interactions with the host. Herein, core-shell fibrous meshes, composed of a polycaprolactone (PCL) core and a functionalized gelatin shell, were prepared by coaxial electrospinning and then photocrosslinked under UV light aiming to be used in vascular tissue regeneration. The suitability of the meshes for the pretended biomedical application was evaluated by assessing their chemical/physical properties as well as their haemo and biocompatibility in vitro. The obtained results revealed that meshes' shell prepared with a higher content of gelatin showed fibers with diameters presenting a unimodal distribution and a mean value of 600nm. Moreover, those fibers with higher content of gelatin also displayed lower water contact angles, and therefore higher hydrophilicities. Such features are crucial for the good biologic performance displayed by these meshes, when in contact with blood and with Normal Human Dermal Fibroblasts cells.

Anti-JCV antibody serostatus and longitudinal evaluation in a Portuguese Multiple Sclerosis population.

Multiple Sclerosis (MS) treatment with natalizumab is associated with Progressive Multifocal Leukoencephalopathy (PML). The risk of PML being related to the anti-JCV antibody index is well established, but there is less known about seroconversion rates in natalizumab-treated patients and longitudinal variation in the anti-JCV antibody index. Our objective was to assess anti-JCV antibody prevalence in an MS population and to evaluate the evolution of the anti-JCV antibody index in natalizumab-treated patients. To assess anti-JCV antibody prevalence, we included all patients who had the anti-JCV antibody test in our consultation, regardless of the treatment. To evaluate the evolution of the anti-JCV antibody index and seroconversion, only natalizumab-treated patients with at least two samples were selected. Demographic characteristics were evaluated. From a total of 371 patients included, 68.19% (n=253) were seropositive for anti-JCV antibodies (JCV+). There was a significant difference in anti-JCV antibody seropositivity concerning gender (male 76.27% vs. female 64.43%, p=0.023), but not age. To evaluate seroconversion, 85 patients who were initially seronegative (JCV-) were selected. The annual rate of seroconversion in the first two years was stable, but after that there was a significant increase with treatment duration (ρ=0.90, p=0.037): in the first year it was 5.88% (n=5/85); in the second, 5.71% (n=4/70); in the third, 6.82% (n=3/44); in the fourth, 10.34% (n=3/29); and in the fifth, 15.0% (n=3/20). The mean index variability was higher in patients who experienced seroconversion (1.16±0.97), followed by JCV+ patients (0.44±0.48), compared to JCV- patients (0.08±0.05). In conclusion, anti-JCV antibody prevalence in our population is comparable to other reported cohorts. The seroconversion rate increased with treatment duration. We found a high fluctuation in the antibody index in JCV+ patients.

Controlled release of moxifloxacin from intraocular lenses modified by Ar plasma-assisted grafting with AMPS or SBMA: An in vitro study.

Intraocular lenses (IOLs) present an alternative for extended, local drug delivery in the prevention of post-operative acute endophthalmitis. In the present work, we modified the surface of a hydrophilic acrylic material, used for manufacturing of IOLs, through plasma-assisted grafting copolymerization of 2-acrylamido-2-methylpropane sulfonic acid (AMPS) or [2-(methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl)ammonium hydroxide (SBMA), with the aim of achieving a controlled and effective drug release. The material was loaded with moxifloxacin (MFX), a commonly used antibiotic for endophthalmitis prevention. The characterization of the modified material showed that relevant properties, like swelling capacity, wettability, refractive index and transmittance, were not affected by the surface modification. Concerning the drug release profiles, the most promising result was obtained when AMPS grafting was done in the presence of MFX. This modification led to a higher amount of drug being released for a longer period of time, which is a requirement for the prevention of endophthalmitis. The material was found to be non-cytotoxic for rabbit corneal endothelial cells. In a second step, prototype IOLs were modified with AMPS and loaded with MFX as previously and, after sterilization and storage (30days), they were tested under dynamic conditions, in a microfluidic cell with volume and renovation rate similar to the eye aqueous humour. MFX solutions collected in this assay were tested against Staphylococcus aureus and Staphylococcus epidermidis and the released antibiotic proved to be effective against both bacteria until the 12th day of release.

3D map distribution of metallic nanoparticles in whole cells using MeV ion microscopy.

In this work, a new tool was developed, the MORIA program that readily translates Rutherford backscattering spectrometry (RBS) output data into visual information, creating a display of the distribution of elements in a true three-dimensional (3D) environment. The program methodology is illustrated with the analysis of yeast Saccharomyces cerevisiae cells, exposed to copper oxide nanoparticles (CuO-NP) and HeLa cells in the presence of gold nanoparticles (Au-NP), using different beam species, energies and nuclear microscopy systems. Results demonstrate that for both cell types, the NP internalization can be clearly perceived. The 3D models of the distribution of CuO-NP in S. cerevisiae cells indicate the nonuniform distribution of NP in the cellular environment and a relevant confinement of CuO-NP to the cell wall. This suggests the impenetrability of certain cellular organelles or compartments for NP. By contrast, using a high-resolution ion beam system, discretized agglomerates of Au-NP were visualized inside the HeLa cell. This is consistent with the mechanism of entry of these NPs in the cellular space by endocytosis enclosed in endosomal vesicles. This approach shows RBS to be a powerful imaging technique assigning to nuclear microscopy unparalleled potential to assess nanoparticle distribution inside the cellular volume.

Long-term effectiveness and safety of natalizumab in a Portuguese population.

OBJECTIVES: Natalizumab long-term effectiveness data in real-world relapsing-remitting multiple sclerosis (RRMS) is needed. Our objective is to report the long-term effectiveness and safety of natalizumab in a cohort of RRMS patients. METHODS: This is a retrospective study of natalizumab treatment for two years or longer in RRMS. Annualized relapse rate, Expanded Disability Status Scale (EDSS), brain magnetic resonance imaging T2 lesion volume, JC virus antibody status, previous treatments and adverse events were analysed. RESULTS: Seventy-one patients were included with a mean treatment duration of 44.86±17.39months. Over the treatment duration there was a significant decrease in annualized relapse rate (88.37%) and EDSS (28.57%); no evidence of clinical disease activity in 73.24% and 61.97% after one and two-years respectively; and brain magnetic resonance imaging T2 lesion volume remained stable. Forty patients suspended natalizumab, in 85% due to high risk of developing progressive multifocal leukoencephalopathy (PML). The major complication was PML (n=3). CONCLUSIONS: Natalizumab showed effectiveness in the long-term follow up period of our cohort, with reduction of ARR, EDSS, and MRI lesion load stabilization. PML was the major complication.

ESPEN guidelines on definitions and terminology of clinical nutrition.

BACKGROUND: A lack of agreement on definitions and terminology used for nutrition-related concepts and procedures limits the development of clinical nutrition practice and research. OBJECTIVE: This initiative aimed to reach a consensus for terminology for core nutritional concepts and procedures. METHODS: The European Society of Clinical Nutrition and Metabolism (ESPEN) appointed a consensus group of clinical scientists to perform a modified Delphi process that encompassed e-mail communication, face-to-face meetings, in-group ballots and an electronic ESPEN membership Delphi round. RESULTS: Five key areas related to clinical nutrition were identified: concepts; procedures; organisation; delivery; and products. One core concept of clinical nutrition is malnutrition/undernutrition, which includes disease-related malnutrition (DRM) with (eq. cachexia) and without inflammation, and malnutrition/undernutrition without disease, e.g. hunger-related malnutrition. Over-nutrition (overweight and obesity) is another core concept. Sarcopenia and frailty were agreed to be separate conditions often associated with malnutrition. Examples of nutritional procedures identified include screening for subjects at nutritional risk followed by a complete nutritional assessment. Hospital and care facility catering are the basic organizational forms for providing nutrition. Oral nutritional supplementation is the preferred way of nutrition therapy but if inadequate then other forms of medical nutrition therapy, i.e. enteral tube feeding and parenteral (intravenous) nutrition, becomes the major way of nutrient delivery. CONCLUSION: An agreement of basic nutritional terminology to be used in clinical practice, research, and the ESPEN guideline developments has been established. This terminology consensus may help to support future global consensus efforts and updates of classification systems such as the International Classification of Disease (ICD). The continuous growth of knowledge in all areas addressed in this statement will provide the foundation for future revisions.

A quantitative proteomic approach to highlight Phragmites sp. adaptation mechanisms to chemical stress induced by a textile dyeing pollutant.

Phragmites sp. is present worldwide in treatment wetlands though the mechanisms involved in the phytoremediation remain unclear. In this study a quantitative proteomic approach was used to study the prompt response and adaptation of Phragmites to the textile dyeing pollutant, Acid Orange 7 (AO7). Previously, it was demonstrated that AO7 could be successfully removed from wastewater and mineralized in a constructed wetland planted with Phragmites sp. This azo dye is readily taken up by roots and transported to the plant aerial part by the xylem. Phragmites leaf samples were collected from a pilot scale vertical flow constructed wetland after 0.25, 3.25 and 24.25h exposure to AO7 (400mgL-1) immediately after a watering cycle used as control. Leaf soluble protein extraction yielded an average of 1560 proteins in a broad pI range (pH3-10) by two-dimensional gel electrophoresis. A time course comparative analysis of leaf proteome revealed that 40 proteins had a differential abundance compared to control (p<0.05) within a 3.25h period. After 24.25h in contact with AO7, leaf proteome was similar to control. Adaptation to AO7 involved proteins related with cellular signalling (calreticulin, Ras-related protein Rab11D and 20S proteasome), energy production and conversion (adenosine triphosphate synthase beta subunit) carbohydrate transport and metabolism (phosphoglucose isomerase, fructose-bisphosphate aldolase, monodehydroascorbate reductase, frutockinase-1 and Hypothetical protein POPTR_0003s12000g and the Uncharacterized protein LOC100272772) and photosynthesis (sedoheptulose-1,7-bisphosphatase and ferredoxin-NADP+ reductase). Therefore, the quantitative proteomic approach used in this work indicates that mechanisms associated with stress cell signalling, energy production, carbohydrate transport and metabolism as well as proteins related with photosynthesis are key players in the initial chemical stress response in the phytoremediation process of AO7.

The Cek1­mediated MAP kinase pathway regulates exposure of α­1,2 and ß­1,2­mannosides in the cell wall of Candida albicans modulating immune recognition.

The Cek1 MAP kinase (MAPK) mediates vegetative growth and cell wall biogenesis in the fungal pathogen Candida albicans. Alterations in the fungal cell wall caused by a defective Cek1­mediated signaling pathway leads to increased ß­1,3­glucan exposure influencing dectin­1 fungal recognition by immune cells. We show here that cek1 cells also display an increased exposure of α­1,2 and ß­1,2­mannosides (α­M and ß­M), a phenotype shared by strains defective in the activating MAPKK Hst7, suggesting a general defect in cell wall assembly. cek1 cells display walls with loosely bound material as revealed by transmission electron microscopy and are sensitive to tunicamycin, an inhibitor of N­glycosylation. Transcriptomal analysis of tunicamycin treated cells revealed a differential pattern between cek1 and wild type cells which involved mainly cell wall and stress related genes. Mapping α­M and ß­M epitopes in the mannoproteins of different cell wall fractions (CWMP) revealed an important shift in the molecular weight of the mannan derived from mutants defective in this MAPK pathway. We have also assessed the role of galectin­3, a member of a ß­galactoside­binding protein family shown to bind to and kill C. albicans through ß­M recognition, in the infection caused by cek1 mutants. Increased binding of cek1 to murine macrophages was shown to be partially blocked by lactose. Galectin-3(-/-) mice showed increased resistance to fungal infection, although galectin-3 did not account for the reduced virulence of cek1 mutants in a mouse model of systemic infection. All these data support a role for the Cek1­mediated pathway in fungal cell wall maintenance, virulence and antifungal discovery.

Development of UV cross-linked gelatin coated electrospun poly(caprolactone) fibrous scaffolds for tissue engineering.

Cardiovascular disease is the leading cause of morbidity and mortality among industrialized countries. Vascular grafts are often required for the surgical treatments. Considering the limitations associated with the use of autografts and with the currently available synthetic materials, a growing demand in tissue engineered vascular grafts has been registered. During the work here described, electrospinning technique was used to prepared fibrous matrices to be applied as vascular implants. For that purpose, electrospun polycaprolactone (PCL) fibrous mats were produced and afterwards coated with different hydrogel formulations based in photocrosslinkable gelatin (GelMA) and the macromers poly(ethylene glycol) acrylate (PEGA) and poly(ethylene glycol) diacrylate (PEGDA). These were further photocrosslinked under UV irradiation using Irgacure® 2959 (by BASF) as the photoinitiator. The suitability of the coated scaffolds for the intended application, was evaluated by assessing their chemical/physical properties as well as their interaction with blood and endothelial cells.

The effectiveness of fingolimod in a Portuguese real-world population.

INTRODUCTION: Fingolimod is an oral treatment for Relapsing-Remitting Multiple Sclerosis (RRMS) with established efficacy in clinical trials. Post-marketing studies are important to assess its effectiveness in real-world populations. OBJECTIVES: To report the effectiveness and safety of fingolimod in a real-world population. METHODS: A retrospective study of patients with RRMS treated with fingolimod for at least six months. The demographic characteristics, Annualized Relapse Rate (ARR), Expanded Disability Status Score (EDSS), previous treatments and Adverse Events (AE) were analysed. RESULTS: 104 patients were included, with a mean treatment duration of 21.06 months. First-line disease modifying therapy failure patients (n=56) had an ARR decrease of 68.53% (1.43 vs. 0.45, p<0.001), 66.07% of them were relapse-free, EDSS significantly decreased (2.5 vs. 2.0, p<0.001) and 91.07% showed no disability progression. In patients previously treated with natalizumab as a second-line drug mainly switched due to safety concerns (n=41), although the differences were not statistically significant, both the ARR and EDSS increased in 41.46% and 19.51% of patients, respectively. In treatment-naive patients (n=7) the ARR decreased 94.90% (1.57 vs. 0.08, p=0.027) and there was no disability progression. 56.7% of all patients experienced AE not considered serious in any of the cases. CONCLUSION: In this population, fingolimod was an effective treatment after first-line treatment failure, decreasing both the ARR and EDSS, and may be an effective option after natalizumab.

Production of new 3D scaffolds for bone tissue regeneration by rapid prototyping.

The incidence of bone disorders, whether due to trauma or pathology, has been trending upward with the aging of the worldwide population. The currently available treatments for bone injuries are rather limited, involving mainly bone grafts and implants. A particularly promising approach for bone regeneration uses rapid prototyping (RP) technologies to produce 3D scaffolds with highly controlled structure and orientation, based on computer-aided design models or medical data. Herein, tricalcium phosphate (TCP)/alginate scaffolds were produced using RP and subsequently their physicochemical, mechanical and biological properties were characterized. The results showed that 60/40 of TCP and alginate formulation was able to match the compression and present a similar Young modulus to that of trabecular bone while presenting an adequate biocompatibility. Moreover, the biomineralization ability, roughness and macro and microporosity of scaffolds allowed cell anchoring and proliferation at their surface, as well as cell migration to its interior, processes that are fundamental for osteointegration and bone regeneration.

Photocurable bioadhesive based on lactic acid.

Novel photocurable and low molecular weight oligomers based on l-lactic acid with proven interest to be used as bioadhesive were successfully manufactured. Preparation of lactic acid oligomers with methacrylic end functionalizations was carried out in the absence of catalyst or solvents by self-esterification in two reaction steps: telechelic lactic acid oligomerization with OH end groups and further functionalization with methacrylic anhydride. The final adhesive composition was achieved by the addition of a reported biocompatible photoinitiator (Irgacure® 2959). Preliminary in vitro biodegradability was investigated by hydrolytic degradation in PBS (pH=7.4) at 37 °C. The adhesion performance was evaluated using glued aminated substrates (gelatine pieces) subjected to pull-to-break test. Surface energy measured by contact angles is lower than the reported values of the skin and blood. The absence of cytoxicity was evaluated using human fibroblasts. A notable antimicrobial behaviour was observed using two bacterial models (Staphylococcus aureus and Escherichia coli). The cured material exhibited a strong thrombogenic character when placed in contact with blood, which can be predicted as a haemostatic effect for bleeding control. This novel material was subjected to an extensive characterization showing great potential for bioadhesive or other biomedical applications where biodegradable and biocompatible photocurable materials are required.

Production and characterization of chitosan/gelatin/ß-TCP scaffolds for improved bone tissue regeneration.

Recently, bone tissue engineering emerged as a viable therapeutic alternative, comprising bone implants and new personalized scaffolds to be used in bone replacement and regeneration. In this study, biocompatible scaffolds were produced by freeze-drying, using different formulations (chitosan, chitosan/gelatin, chitosan/ß-TCP and chitosan/gelatin/ß-TCP) to be used as temporary templates during bone tissue regeneration. Sample characterization was performed through attenuated total reflectance-Fourier transform infrared spectroscopy, X-ray diffraction and energy dispersive spectroscopy analysis. Mechanical characterization and porosity analysis were performed through uniaxial compression test and liquid displacement method, respectively. In vitro studies were also done to evaluate the biomineralization activity and the cytotoxic profile of the scaffolds. Scanning electron and confocal microscopy analysis were used to study cell adhesion and proliferation at the scaffold surface and within their structure. Moreover, the antibacterial activity of the scaffolds was also evaluated through the agar diffusion method. Overall, the results obtained revealed that the produced scaffolds are bioactive and biocompatible, allow cell internalization and show antimicrobial activity against Staphylococcus aureus. Such, make these 3D structures as potential candidates for being used on the bone tissue regeneration, since they promote cell adhesion and proliferation and also prevent biofilm development at their surfaces, which is usually the main cause of implant failure.

Chitosan/arginine-chitosan polymer blends for assembly of nanofibrous membranes for wound regeneration.

Frequently, skin is subjected to damaging events, such as deep cuts, burns or ulcers, which may compromise the integrity of this organ. To overcome such lesions, different strategies have been employed. Among them, wound dressings aimed to re-establish skin native properties and decreased patient pain have been pursued for a long time. Herein, an electrospun membrane comprised by deacetylated/arginine modified chitosan (CH-A) was produced to be used as a wound dressing. The obtained results showed that the membrane has a highly hydrophilic and porous three-dimensional nanofibrous network similar to that found in human native extracellular matrix. In vitro data indicate that human fibroblasts adhere and proliferate in contact with membranes, thus corroborating their biocompatibility. This nanofiber-based biomaterial also demonstrated bactericidal activity for two bacterial strains. In vivo application of CH-A nanofibers in full thickness wounds resulted in an improved tissue regeneration and faster wound closure, when compared to non-modified membranes. Such findings support the suitability of using this membrane as a wound dressing in a near future.

Investigation of the multifaceted iron acquisition strategies of Burkholderia cenocepacia.

Burkholderia cenocepacia is a bacterial pathogen which causes severe respiratory infections in cystic fibrosis (CF). These studies were aimed at gaining an insight into the iron acquisition strategies of B. cenocepacia. In iron restricted conditions, genes associated with the synthesis and utilisation of ornibactin (pvdA, orbA, orb F) were significantly upregulated compared to the expression of pyochelin associated genes (pchD, fptA). In the absence of alternative iron sources, B. cenocepacia J2315 and 715j utilised ferritin and haemin, but not transferrin or lactoferrin for growth. Significantly, mutants unable to produce ornibactin, (715j-orbI) or ornibactin and pyochelin, (715j-pobA), utilised haemin and ferritin more efficiently than the wild-type. Moreover, both mutants were also able to utilise lactoferrin for growth (P ≤ 0.01) and additionally 715j-pobA utilised transferrin (P ≤ 0.01), potentially facilitating adaptation to the host environment. Furthermore, B. cenocepacia increased ornibactin gene expression in response to pyoverdine from Pseudomonas aeruginosa (P ≤ 0.01), demonstrating the capacity to compete for iron in co-colonised niches. Pyoverdine also significantly diminished the growth of B. cenocepacia (P < 0.001) which was related to its iron chelating activity. In a study of three B. cenocepacia sequential clonal isolates obtained from a CF patient over a 3.5 year period, ornibactin upregulation in response to pyoverdine was less pronounced in the last isolate compared to the earlier isolates, as was growth in the presence of haemin and ferritin, indicating alternative iron acquisition mechanism(s) may dominate as chronic infection progresses. These data demonstrate the multifaceted iron acquisition strategies of B. cenocepacia and their capacity to be differentially activated in the presence of P. aeruginosa and during chronic infection.

Presynaptic adenosine A2A receptors dampen cannabinoid CB1 receptor-mediated inhibition of corticostriatal glutamatergic transmission.

BACKGROUND AND PURPOSE: Both cannabinoid CB1 and adenosine A2A receptors (CB1 receptors and A2A receptors) control synaptic transmission at corticostriatal synapses, with great therapeutic importance for neurological and psychiatric disorders. A postsynaptic CB1 -A2A receptor interaction has already been elucidated, but the presynaptic A2A receptor-mediated control of presynaptic neuromodulation by CB1 receptors remains to be defined. Because the corticostriatal terminals provide the major input to the basal ganglia, understanding the interactive nature of converging neuromodulation on them will provide us with novel powerful tools to understand the physiology of corticostriatal synaptic transmission and interpret changes associated with pathological conditions. EXPERIMENTAL APPROACH: Pharmacological manipulation of CB1 and A2A receptors was carried out in brain nerve terminals isolated from rats and mice, using flow synaptometry, immunoprecipitation, radioligand binding, ATP and glutamate release measurement. Whole-cell patch-clamp recordings were made in horizontal corticostriatal slices. KEY RESULTS: Flow synaptometry showed that A2A receptors were extensively co-localized with CB1 receptor-immunopositive corticostriatal terminals and A2A receptors co-immunoprecipitated CB1 receptors in these purified terminals. A2A receptor activation decreased CB1 receptor radioligand binding and decreased the CB1 receptor-mediated inhibition of high-K(+) -evoked glutamate release in corticostriatal terminals. Accordingly, A2A receptor activation prevented CB1 receptor-mediated paired-pulse facilitation and attenuated the CB1 receptor-mediated inhibition of synaptic transmission in glutamatergic synapses of corticostriatal slices. CONCLUSIONS AND IMPLICATIONS: Activation of presynaptic A2A receptors dampened CB1 receptor-mediated inhibition of corticostriatal terminals. This constitutes a thus far unrecognized mechanism to modulate the potent CB1 receptor-mediated presynaptic inhibition, allowing frequency-dependent enhancement of synaptic efficacy at corticostriatal synapses.

New drug-eluting lenses to be applied as bandages after keratoprosthesis implantation.

Corneal tissue is the most commonly transplanted tissue worldwide. This work aimed to develop a new drug-eluting contact lens that may be used as a bandage after keratoprosthesis. During this work, films were produced using poly(vinyl alcohol) (PVA) and chitosan (CS) crosslinked with glyoxal (GL). Vancomycin chlorhydrate (VA) was impregnated in these systems by soaking. Attenuated total reflectance - Fourier transform infrared spectroscopy was used to confirm crosslinking. The cytotoxic and drug release profile, hydrophilicity, thermal and biodegradation as well as swelling capacity of the samples were assessed through in vitro studies. PVA and PVA/CS films were obtained by crosslinking with GL. The films were transparent, flexible with smooth surfaces, hydrophilic and able to load and release vancomycin for more than 8h. Biodegradation in artificial lachrymal fluid (ALF) with lysozyme at 37°C showed that mass loss was higher for the samples containing CS. Also, the samples prepared with CS showed the formation of pores which were visualized by SEM. All samples revealed a biocompatible character after 24h in contact with cornea endothelial cells. As a general conclusion it was possible to determine that the 70PVA/30CS film showed to combine the necessary features to prepare vancomycin-eluting contact lenses to prevent inflammation after corneal substitution.

Manufacture of ß-TCP/alginate scaffolds through a Fab@home model for application in bone tissue engineering.

The growing need to treat bone-related diseases in an elderly population compels the development of novel bone substitutes to improve patient quality of life. In this context, the advent of affordable and effective rapid prototyping equipment, such as the Fab@home plotter, has contributed to the development of novel scaffolds for bone tissue engineering. In this study, we report for the first time the use of a Fab@home plotter for the production of 3D scaffolds composed by beta-tricalcium phosphate (ß-TCP)/alginate hybrid materials. ß-TCP/alginate mixtures were used in a proportion of 50/50% (w/w), 30/70% (w/w) and 20/80% (w/w). The printing parameters were optimized to a nozzle diameter of 20 Gauge for the production of rigid scaffolds with pre-defined architectures. We observed that, despite using similar printing parameters, both the precision and resolution of the scaffolds were significantly affected by the blend's viscosity. In particular, we demonstrate that the higher viscosity of 50/50 scaffolds (150.0 ± 3.91 mPa s) provides a higher precision in the extrusion process. The physicochemical and biological characterization of the samples demonstrated that the 50/50 scaffolds possessed a resistance to compression comparable to that of native trabecular bone. Moreover, this particular formulation also exhibited a Young's modulus that was higher than that of trabecular bone. Scanning electron microscopy and fluorescence microscopy analysis revealed that osteoblasts were able to adhere, proliferate and also penetrate into the scaffold's architecture. Altogether, our findings suggest that the Fab@home printer can be employed in the manufacture of reproducible scaffolds, using a formulation 50/50 alginate-ß-TCP that has suitable properties to be applied as bone substitutes in the future.