Preparation and in vitro evaluation of PLA/biphasic calcium phosphate filaments used for fused deposition modelling of scaffolds.

Ceramic materials such as calcium phosphates (CaPs) with a composition similar to the mineral phase of bones and polymeric polylactic acid (PLA) are potential candidates for the manufacturing of scaffolds to act as bone substitutes and for tissue engineering applications, due to their bioresorbability and biocompatibility. Variables such as porosity, topography, morphology, and mechanical properties play an essential role in the scaffolds response. In this paper, a polymer/ceramic composite filament of 1.7 mm in diameter based on PLA and biphasic calcium phosphates (BCPs) was obtained by hot-melt extrusion in a single screw extruder. The particles of BCP were obtained by solution-combustion synthesis, and the PLA used was commercial grade. The BCPs ceramics were characterized by X-ray diffraction (XRD), scanning electron microscopic (SEM), transmission electron microscopy (TEM), and Brunauer, Emmett, and Teller (BET). It was possible to confirm that the main inorganic phases were hydroxyapatite (HAP) and tricalcium phosphate (TCP) with grain sizes below 100 nm and with high porosity. The Filaments obtained are a bit fragile but were able to be used in fused deposition modelling (FDM) using low-cost commercial printers. The filaments were characterized by SEM and energy dispersive X-ray (EDX). The in-vitro tests of filaments showed deposition of apatite phases on their surface, non-cytotoxic behavior, adequate cell proliferation and cell adhesion.

Solution-combustion synthesis of doped TiO2 compounds and its potential antileishmanial activity mediated by photodynamic therapy.

Photodynamic therapy has emerged as an alternative treatment for cutaneous leishmaniasis, and compounds with photocatalytic behavior are promising candidates to develop new therapeutic strategies for the treatment of this parasitic disease. Titanium dioxide TiO2 is a semiconductor ceramic material that shows excellent photocatalytic and antimicrobial activity under Ultraviolet irradiation. Due to the harmful effects of UV radiation, many efforts have been made in order to enhance both photocatalytic and antimicrobial properties of TiO2 in the visible region of the spectrum by doping or through modifications in the route of synthesis. Herein, Fe-, Zn-, or Pt- doped TiO2 nanostructures were synthesized by solution-combustion route. The obtained compounds presented aggregates of 100 nm, formed by particles smaller than 20 nm. Doping compounds shift the absorption spectrum towards the visible region, allowing production of reactive oxygen species in the presence of oxygen and molecular water when the system is irradiated in the visible spectrum. The Pt (EC50 = 18.2 ±â€¯0.8 µg/mL) and Zn (EC50 = 16.4 ±â€¯0.3 µg/mL) -doped TiO2 presented the higher antileishmanial activities under visible irradiation and their application as photosensitizers in photodynamic therapy (PDT) strategies for the treatment of cutaneous leishmaniasis should be considered.

Synthesis of calcium phosphate nanostructures by combustion in solution as a potential encapsulant system of drugs with photodynamic properties for the treatment of cutaneous leishmaniasis.

The traditional drugs used in the treatment of cutaneous leishmanisis (CL) have multiple disadvantages, such as high toxicity, high costs, and more recently the appearance of parasites resistant to those drugs. For this reason, some research has focused on the development of new drugs or treatment therapies. Photodynamic therapy (PDT) that involves the use of a photosensitive or photosensitizing compound capable of producing reactive oxygen species to which Leishmania parasites are sensitive, has emerged as an alternative for the treatment of CL. However, some of these sensitizing compounds exhibit some toxicity (cytotoxicity, allergic reaction, etc), low selectivity, and some of them are insoluble in aqueous media limiting their use. Therefore, the PDT can be improved using encapsulation systems which protect drugs, prevent their degradation, help them overcome physical barriers and increase their selectivity. In this study, we propose the use of calcium phosphate as a potential encapsulant or photodynamic support for photoactive drugs, using hypericin (HY) as a photosensitizer agent. The self-combustion route was used to synthesize the CP nanostructures. The structure and morphology of CP nanoparticles were evaluated via X-ray diffraction (XRD), Raman and field-emission scanning electron microscopy (FE-SEM). Phases rich in hydroxyapatite and CP ß phase, with granular morphology and an average grain size of 42.9 nm were obtained. The encapsulation uptake and the interactions between HY and the encapsulated system were evaluated by fluorescence spectroscopy and Fourier-transform infrared spectroscopy (FTIR), respectively. Approximately 13% of HY was enapsulated per 1 µg of nanoparticles of calcium phosphate. Composites were submitted to in vitro assays of cytotoxicity and anti-leishmanial activity. The CP nanoparticles did not affect the photodynamic activity of HY. On the contrary they showed antileishmanial response.

Study of association of CTLA4 gene variants to non-anterior uveitis.

This study was undertaken to investigate the possible genetic association of functional CTLA4 polymorphisms with susceptibility to non-anterior uveitis. Four hundred and seventeen patients with endogenous non-anterior uveitis and 1517 healthy controls of Spanish Caucasian origin were genotyped for the CTLA4 polymorphisms rs733618, rs5742909 and rs231775, using predesigned TaqMan(©) allele discrimination assays. PLINK software was used for the statistical analyses. No significant associations between the CTLA4 polymorphisms and susceptibility to global non-anterior uveitis were found. It was also the case when the potential association of these genetic variants with the anatomical localization of the disease, such as intermediate, posterior or panuveitis, was assessed. Our results do not support a relevant role of these CTLA4 polymorphisms in the non-anterior uveitis genetic predisposition.

Cytokine production by non-stimulated peripheral blood NK cells and lymphocytes in early-onset severe pre-eclampsia without HELLP.

Preeclampsia involves an exacerbated maternal inflammatory response that suggests a possible role of innate immunity. NK cells can promote this kind of response through cytokine production and the expression of activating or inhibitory receptors. The aims of the present study were to explore cytokine production by peripheral blood mononuclear cells, as well as cytotoxic ability and receptor expression for HLA-E and HLA-G molecules in peripheral natural killer (NK) cells of women with early-onset severe preeclampsia without HELLP (hemolysis, elevated liver enzyme levels and a low platelet count) syndrome. The expression of the ILT2, KIRDL4, NKG2A, and NKG2C receptors and of cytotoxic activity was measured in non-stimulated NK cells, whereas the intracellular expression of IL-4, IL-10, IL-13, IL-12, IFNγ, TNF and VEGF, was assessed in non-stimulated peripheral blood mononuclear cells subsets using flow cytometry. Circulating soluble HLA-G was also determined by ELISA. The intracellular cytokines tested were significantly higher in NK cell subsets from severely preeclamptic women compared with the control group. On the other hand, the percentage of NK cells expressing NKG2A or NKG2C and the cytotoxic activity of NK cells were significantly higher in severely preeclamptic women. Furthermore, there was a significant correlation between urine protein concentration and soluble human leukocyte antigen G (soluble HLA-G) in serum. We conclude that patients with early-onset severe preeclampsia without HELLP syndrome have increased NK cell function related to cytokine production, cytotoxicity and expression of lectin-like receptors such as NKG2.

Estudio comparativo del efecto clínico producido por el first class y el péndulo en pacientes atendidos en la Facultad de Odontología de la Univesidad de Antioquia. Análisis radiográfico y de modelos / Comparative study of the clinical effect produced by the first class and the pendulum in patients trated at the College of Dentistry, University of Antioquia. A radiographic and model analysis

El propósito de este estudio fue establecer y comparar los resultados clínicos y radiográficos obtenidos con el del péndulo y del First class® durante cuatro meses de tratamiento, en relación con sus efectos craneofaciales, dentales y de tejidos blandos en pacientes que tuvieran indicado dentro de su plan de tratamiento la distalización de los primeros molares superiores. La muestra estuvo constituida por 27 sujetos entre los 12 y 17 años de edad: 19 experimentales (11 tratados con péndulo y 8 con First class®) y 8 controles, con los cuales se descartaron cambios debidos al crecimiento. Se obtuvieron radiografías panorámicas iniciales y cefálicas laterales iniciales y finales; fotografías estandarizadas 1:1 de modelos de estudio: al inicio, segundo y cuarto mes de tratamiento. Los resultados radiográficos muestran que no se presentan cambios significativos en las estructuras esqueléticas. A nivel dentoalveolar se observa distalización molar promedio con el péndulo de 4,68 ± 4,9 mm y con el First class® de 2,05 ± 4,06 mm acompañadas ambas de inclinación distal (12,2º con péndulo, 3,2º con First class®) e intrusión (0,55 y 0,037 mm respectivamente) con comportamiento asimétrico derecha-izquierda. Por cada milímetro de distalización molar se presentó un incremento en la labialización del incisivo de 0,9º con el péndulo y de 3,0º con el First class® que se acompaña de disminución del ángulo naso-labial (-5,45º con péndulo y -6,0º con First class®) y protrusión del labio superior (1,59 y 1,07 mm respectivamente). En los modelos se observó un cambio rotacional del molar con un comportamiento heterogéneo; tanto con péndulo como con First class®, se observan rotaciones en sentidos opuestos: distopalatinas (+) y distovestibulares (-) El promedio total fue positivo en ambos siendo mayor para el First class® (5,87°) que para el péndulo (4,3°), conservando un patrón asimétrico derecha-izquierda. Debe cuestionarse la efectividad del anclaje ofrecido por el botón de acríli...

The purpose of this research was to establish and compare the clinical and radiographic results obtained during the four month use of the pendulum and the First class® in relation with its craneofacial, dental, and soft tissue effects in patients who had indicated as part of their treatment plan, a distalization of their first upper molars. The sample consisted of 27 subjects between 12 and 17 years of age: 11 treated with pendulum, 8 treated with First class®, and 8 controls to discard any changes due to growth. All patients received inicial Panoramic X-rays, inicial and final lateral cephalograms; 1:1 standardized pictures of study casts at the beginning, second and fourth months of treatment. The radiographic results showed there were no significant changes in the skeletal structures. At the dento-alveolar level an average molar distalization of 4.68 ± 4.9 mm was observed with the pendulum and of 2.05 ± 4.06 mm with the First class® both of which were accompanied by distal inclination (12.2º pendulum, 3.2º First class®) and intrusion (0.55 and 0.037 mm respectively) with an assymetric right – left behavior. For each millimeter of molar distalization there was an increment in incisal labialization of 0.9º with the pendulum and 3.0º with the First class® accompanied by a decrease in the nasolabial angle (-5.45º with the pendulum and -6.0º with First class®) and an upper lip protrusion (1.59 and 1.07 mm respectively). The dental casts showed a rotational change in the molar with a heterogenous behavior; with both pendulum and First class®, rotations in opposite directions were observed: distopalatal (+) y distolabial (-). The total average was positive in both, being greater for the First class® (5.87°) than for the pendulum (4.3°), conserving a right-left asymmetric pattern. The effectiveness of the anchorage offered by the palatal acrylic button should be questioned, since there was evidence of anterior displacement of this structure...

Evaluación de la asimetría mandibular con radiografías oblicuas y fotografías clínicas en niños de 5 años / Evaluation of mandibular asymmetry with oblique radiographs and clinical photographs in 5-year-old children

El propósito de este estudio fue evaluar la asimetría mandibular en un rupo de niños y niñas de 5 años de edad de la ciudad de Medellín, utilizando técnicas radiográficas (radiografía oblicua mandibular de 45º) y fotografía lateral y frontal). La muestra consistió en 83 niños (46 niños y 37 niñas) para la evaluación radiográfica, de ellos, 50 niños (25 niños y 25 niñas) para la evaluación fotográfica. A partir de la evaluación radiográfica se encontró acuerdo con el promedio, las medidas mandibulares lineales fueron mayores en el lado izquierdo; el ángulo gonial fue mayor en el lado derecho. No se observaron diferencias estadísticamente significativas en las medidas entre niños y niñas. A partir de la evalución de las fotografías faciales laterlaes no se observaron diferencias del lado mandibular entre el lado derecho y el izquierdo. En general, los niños presentaron más asimetrías que las niñas.