8 research outputs found

    EudragitÂź L100/chitosan composite thin bilayer films for intravaginal pH-responsive release of Tenofovir

    Get PDF
    [EN] The high rate of HIV new infections and AIDS-related deaths each year make prevention tools still necessary today. Different dosage forms – including films – for vaginal administration of antiretroviral drugs have been developed for this purpose. Six batches of Tenofovir-loaded films were formulated based on Eudragit¼ L100 (EL100) and chitosan, containing triethyl citrate and glycerol. In all the cases films structured in two layers – the upper layer mainly attributed to EL100 and the lower layer to chitosan – were revealed by SEM. A higher content in EL100 and plasticizers improves the mechanical properties and control over drug release in the vaginal medium without affecting mucoadhesion. The EL100-based layer acts as a structuring agent that controls Tenofovir release for days in the vaginal medium while it occurs in a few hours in the presence of seminal fluid. Bilayer films with the highest tested content of EL100 and plasticizers would be the most suitable as vaginal microbicides as they are easier to administer due to their excellent mechanical properties and they offer more comfortable posology and enhanced protection against HIV during intercourse due to their pH-responsive release of Tenofovir.This work was supported by the Spanish Research Agency and the European Regional Development Fund (AEI/FEDER, UE) [MAT2016-76416-R]

    Amino Functionalized Micro-Mesoporous Hybrid Particles for the Sustained Release of the Antiretroviral Drug Tenofovir

    Get PDF
    © 2020 by the authors.The sustained release of an antiretroviral agent to women mucosa has been proved as an excellent strategy to reduce the sexual transmission of HIV. Hybrid micro-mesoporous particles have been synthesized and functionalized with a silane coupling agent followed by loading the antiretroviral tenofovir. It has been observed that the disposition of the silane molecule on the surface of the particles determines the interaction mechanism with the antiretroviral molecule loaded independently on the surface area of the particles. In this sense, available and free amino groups are required to achieve a smart pH-responsive material, a condition that is only achieved in those materials containing a silane chemisorbed monolayer. Moreover, the modulation of the release kinetics attributed to the presence of the silane monolayer covering the mesopores has been confirmed by fitting the releasing curves to the first order and Weibull models. The developed micro-mesoporous particles have been demonstrated to be excellent smart-release vehicles for antiviral agents and can be safely used in polymer mucoadhesive vaginal gels.This work was supported by the Spanish Research Agency and the European Regional Development Fund (AEI/FEDER, UE), grant number MAT2016-76416-R.Peer reviewe

    Analysis of the Use and Applicability of Different Variables for the Prescription of Relative Intensity in Bench Press Exercise

    Get PDF
    The aim of the study was to analyze the use of variables such as % of one-repetition maximum (1RM) and number of maximal repetitions (xRM) with execution velocity to define and control the intensity of resistance training in bench press exercise. Hence, exercise professionals will achieve better control of training through a greater understanding of its variables. Methods: In this cross-sectional study, fifty male physical education students were divided into four groups according to their relative strength ratio (RSR) and performed a 1RM bench press test (T1). In the second test, participants performed repetitions to exhaustion (T2), using a relative load corresponding to 70% 1RM determined through the mean propulsive velocity (MPV) obtained from the individual load–velocity relationship. This same test was repeated a week later (T3). Tests were monitored according to the MPV of each repetition and blood lactate values (LACT). Results: Regarding MPV, the best (fastest) repetition of the set (MPVrep Best) values were similar between groups (0.62 m·s−1–0.64 m·s−1), with significant differences in relation to the high RSR group (p 0.05). Average LACT values (5.72 mmol·L−1) showed significant differences between the Background: Medium RSR and Very Low RSR groups. No significant differences were found (p > 0.05) between T2 and T3 with regards to MNR, MPVrep Best, or MPVrep Last, with little variability seen between participants. Conclusions: The use of variables such as the 1RM, estimated using an absolute load value, or an MNR do not allow an adequate degree of precision to prescribe and control the relative intensity of resistance training. Besides, execution velocity control can offer an adequate alternative to guarantee an accurate prescription of intensity with regard to resistance training.SecciĂłn Deptal. de RadiologĂ­a, RehabilitaciĂłn y Fisioterapia (EnfermerĂ­a)Fac. de EnfermerĂ­a, Fisioterapia y PodologĂ­aTRUEpu

    The sports commitment in football players and its relationship with the coach performance: A systematic review

    No full text
    The objective of the article was to relate the sports commitment of the football players together with the performance of the coach to test the relationship that both have with the sporting success of the football players. The PRISMA methodology was used. The Web of Science, Scopus, Academic Search Ultimate, Eric, Medline and Sport Discuss databases were used, with no time limit. The PICO strategy was used to screen articles. Finally, a total of 8 articles were included in the review. The importance between the commitment and the interpersonal style of the coach was demonstrated, which includes aspects in relation to his way of working globally, which we call performance. An increase in the level of commitment was also observed as the performance of the coach improved, especially the motivational climate that this produces in the players. For this reason, it is necessary to take care of these aspects in coaches when they work with potential sports talent

    Mucoadhesive Vaginal Discs based on Cyclodextrin and Surfactants for the Controlled Release of Antiretroviral Drugs to Prevent the Sexual Transmission of HIV

    No full text
    The strategies for developing vaginal microbicides to protect women against human immunodeficiency virus (HIV) sexual transmission are constantly changing. Although the initial dosage forms required daily administration to offer effective protection, the trend then moved towards sustained-release dosage forms that require less frequency of administration in order to improve women’s compliance with the treatment. Nevertheless, another possible strategy is to design on-demand products that can be used in a coitally-dependent manner and only need to be administered immediately before intercourse to offer protection. Vaginal discs based on freeze-dried hydroxypropylmethyl cellulose gels have been developed for this purpose, containing two surfactants, i.e., sodium dodecyl sulphate and polysorbate 60, alone or in combination with 2-hydroxypropyl-ÎČ-cyclodextrin, to achieve a formulation capable of incorporating both hydrophilic and lipophilic drugs. Several studies have been carried out to evaluate how the inclusion of these substances modifies the structure of gels (viscosity and consistency studies) and the porosimetry of the freeze-dried discs (scanning electron microscopy micrographs, mechanical properties, swelling behaviour). The drug release and mucoadhesive properties of the discs have also been evaluated with a view to their clinical application. The systems combining sodium dodecyl sulphate and 2-hydroxypropyl-ÎČ-cyclodextrin were found to be adequate for the vaginal administration of both Tenofovir and Dapivirine and also offer excellent mucoadhesion to vaginal tissue; these discs could therefore be an interesting option for a coitally-dependent administration to protect women against HIV transmission.This work was supported by the Spanish Research Agency and the European Regional Development Fund (AEI/FEDER, UE) [grant number MAT2016-76416-R]

    Chitosan-Based Mucoadhesive Vaginal Tablets for Controlled Release of the Anti-HIV Drug Tenofovir

    Get PDF
    Vaginal microbicides have the potential to give women at high risk of contracting HIV the option of self-protection by preventing the sexual transmission of the virus. In this paper, mucoadhesive vaginal tablets based on chitosan, alone and in combination with pectin and locust bean gum, were developed for the sustained release of tenofovir (an antiretroviral drug). The formulations were placed in simulant vaginal fluid (SVF) to swell, and Hg porosity and SEM microscopy were used for the microstructural characterization of the swelling witnesses. The results show that the association of pectin and chitosan generated polyelectrolyte complexes and produced a robust system able to maintain its structure during the swelling process, when small pores are formed. Drug release and bovine vaginal mucoadhesion studies were performed in SVF showing that tenofovir-controlled dissolution profiles and adhesion to the mucosa were conditioned by the swelling processes of the polymer/s in each formulation. Tablets based on chitosan/pectin have the most homogeneous tenofovir dissolution profiles and last up to 96 h, remaining attached to the vaginal mucosa for the same period. These formulations can therefore be considered a good option for the self-protection of women from the sexual transmission of HIV.This work was supported by projects MAT2012-34552 from the Spanish Ministry of Economy, Industry and Competitiveness, and MAT2016-76416-R financed by the Spanish Research Agency and the European Regional Development Fund (AEI/FEDER, UE).We acknowledge support by the CSIC Open Access Publication Initiative through its Unit of Information Resources for Research (URICI)Peer reviewe

    Reproducibility and Applicability of Traditional Strength Training Prescription Recommendations

    Get PDF
    Background: The aim of this study was to verify the reproducibility of a resistance training protocol in the bench press (BP) exercise, based on traditional recommendations, analysing the effect of the muscle fatigue of each set and of the whole exercise protocol. Methods: In this cross-sectional study, thirty male physical education students were divided into three groups according to their relative strength ratio (RSR), and they performed a 1RM BP test (T1). In the second session (T2), which was one week after T1, the participants performed a BP exercise protocol of three sets with the maximum number of repetitions (MNR) possible to muscle failure, using a relative load corresponding to 70% 1RM determined through the mean propulsive velocity (MPV) obtained from the individual load–velocity relationship, with 2 min rests between sets. Two weeks later, a third session (T3) identical to the second session (T2) was performed. The MPV of each repetition of each set and the blood lactate level after each set were calculated, and mechanical fatigue was quantified through the velocity loss percentage of the set (% loss MPV) and in a pre-post exercise test with an individual load that could be lifted at ~1 m·s−1 of MPV. Results: The number of repetitions performed in each set was significantly different (MNR for the total group of participants: set 1 = 12.50 ± 2.19 repetitions, set 2 = 6.06 ± 1.98 repetitions and set 3 = 4.20 ± 1.99 repetitions), showing high variation coefficients in each of the sets and between groups according to RSR. There were significant differences also in MPVrep Best (set 1 = 0.62 ± 0.10 m·s−1, set 2 = 0.42 ± 0.07 m·s−1, set 3 = 0.36 ± 0.10 m·s−1), which significantly reduced the % loss MPV of all sets (set 1 = 77.4%, set 2 = 64%, set 3 = 54.2%). The lactate levels increased significantly (p < 0.05) (set 1 = 4.9 mmo·L−1, set 2 = 6 mmo·L−1, set 3 = 6.5 mmo·L−1), and MPV loss at 1 m·s−1 after performing the three sets was 36% in T2 and 34% in T3, with acceptable intrasubject variability (MPV at 1 m·s−1 pre-exercise: SEM ≤ 0.09 m·s−1, CV = 9.8%; MPV at 1 m·s−1 post-exercise: SEM ≤ 0.07 m·s−1, CV = 11.7%). Conclusions: These exercise propositions are difficult to reproduce and apply. Moreover, the number of repetitions performed in each set was significantly different, which makes it difficult to define and control the intensity of the exercise. Lastly, the fatigue generated in each set could have an individual response depending on the capacity of each subject to recover from the preceding maximum effort

    Associations between dietary polyphenols and type 2 diabetes in a cross-sectional analysis of the PREDIMED-Plus Trial: role of body mass index and sex

    Get PDF
    Overweight and obesity are important risk factors for type 2 diabetes (T2D). Moving towards healthier diets, namely, diets rich in bioactive compounds, could decrease the odds of suffering T2D. However, those individuals with high body mass index (BMI) may have altered absorption or metabolism of some nutrients and dietary components, including polyphenols. Therefore, we aimed to assess whether high intakes of some classes of polyphenols are associated with T2D in a population with metabolic syndrome and how these associations depend on BMI and sex. This baseline cross-sectional analysis includes 6633 participants from the PREDIMED-Plus trial. Polyphenol intakes were calculated from food frequency questionnaires (FFQ). Cox regression models with constant time at risk and robust variance estimators were used to estimate the prevalence ratios (PRs) for polyphenol intake and T2D prevalence using the lowest quartile as the reference group. Analyses were stratified by sex and BMI groups (overweight and obese) to evaluate potential effect modification. Catechins, proanthocyanidins, hydroxybenzoic acids, and lignans were inversely associated with T2D. Hydroxycinnamic acids were directly related in men. These associations were different depending on sex and BMI, that is, women and overweight obtained stronger inverse associations.The PREDIMED-Plus trial was supported by the official Spanish Institutions for funding scientific biomedical research, CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn) and Instituto de Salud Carlos III (ISCIII), through the Fondo de Investigación para la Salud (FIS), which is co-funded by the European Regional Development Fund (four coordinated Fondo de Investigaciones Sanitarias projects leaded by J.S.-S. and J.V., including the following projects: PI13/00673, PI13/00492, PI13/00272, PI13/01123, PI13/00462, PI13/00233, PI13/02184, PI13/00728, PI13/01090, PI13/01056, PI14/01722, PI14/00636, PI14/00618, PI14/00696, PI14/01206, PI14/01919, PI14/00853, PI14/01374, PI14/00972, PI14/00728, PI14/01471, PI16/00473, PI16/00662, PI16/01873, PI16/01094, PI16/00501, PI16/00533, PI16/00381, PI16/00366, PI16/01522, PI16/01120, PI17/00764, PI17/01183, PI17/00855, PI17/01347, PI17/00525, PI17/01827, PI17/00532, PI17/00215, PI17/01441, PI17/00508, PI17/01732, and PI17/00926), the Especial Action Project entitled Implementación y evaluación de una intervención intensiva sobre la actividad física Cohorte PREDIMED-Plus grant to J.S.-S., European Research Council (Advanced Research Grant 2014–2019, 340918) to M.Á.M.-G., the Recercaixa grant to J.S.-S. (2013ACUP00194), grants from the Consejería de Salud de la Junta de Andalucía (PI0458/2013, PS0358/2016, and PI0137/2018), a grant from the Generalitat Valenciana (PROMETEO/2017/017), a SEMERGEN grant, a CICYT grant provided by the Ministerio de Ciencia, Innovación y Universidades (AGL2016-75329-R), and funds from the European Regional Development Fund (CB06/03). Food companies Hojiblanca (Lucena, Spain) and Patrimonio Comunal Olivarero (Madrid, Spain) donated extra virgin olive oil, and the Almond Board of California (Modesto, CA, USA), American Pistachio Growers (Fresno, CA, USA), and Paramount Farms (Wonderful Company, LLC, Los Angeles, CA, USA) donated nuts. J.K. was supported by the “FOLIUM” program within the FUTURMed project entitled Talent for the medicine within the future from the Fundació Institut d’Investigació Sanitària Illes Balears. This call was co-financed at 50% with charge to the Operational Program FSE 2014-2020 of the Balearic Islands
    corecore