Controlling the 3D architecture of Self-Lifting Auto-generated Tissue Equivalents (SLATEs) for optimized corneal graft composition and stability

Ideally, biomaterials designed to play specific physical and physiological roles in vivo should comprise components and microarchitectures analogous to those of the native tissues they intend to replace. For that, implantable biomaterials need to be carefully designed to have the correct structural and compositional properties, which consequently impart their bio-function. In this study, we showed that the control of such properties can be defined from the bottom-up, using smart surface templates to modulate the structure, composition, and bio-mechanics of human transplantable tissues. Using multi-functional peptide amphiphile-coated surfaces with different anisotropies, we were able to control the phenotype of corneal stromal cells and instruct them to fabricate self-lifting tissues that closely emulated the native stromal lamellae of the human cornea. The type and arrangement of the extracellular matrix comprising these corneal stromal Self-Lifting Analogous Tissue Equivalents (SLATEs) were then evaluated in detail, and was shown to correlate with tissue function. Specifically, SLATEs comprising aligned collagen fibrils were shown to be significantly thicker, denser, and more resistant to proteolytic degradation compared to SLATEs formed with randomly-oriented constituents. In addition, SLATEs were highly transparent while providing increased absorption to near-UV radiation. Importantly, corneal stromal SLATEs were capable of constituting tissues with a higher-order complexity, either by creating thicker tissues through stacking or by serving as substrate to support a fully-differentiated, stratified corneal epithelium. SLATEs were also deemed safe as implants in a rabbit corneal model, being capable of integrating with the surrounding host tissue without provoking inflammation, neo-vascularization, or any other signs of rejection after a 9-months follow-up. This work thus paves the way for the de novo biofabrication of easy-retrievable, scaffold-free human tissues with controlled structural, compositional, and functional properties to replace corneal, as well as other, tissuesThis study was supported by the Medical Research Council grant MR/ K017217/1, the Biotechnology and Biological Sciences Research Council, grant BB/I008187/1 and the Spanish Plan Nacional de Investigación Científica, Desarrollo e Innovación Tecnológica (I + D + I) from the Spanish Ministry of Economy and Competitiveness (Instituto de Salud Carlos III), grant FIS PI14/0955 (cofinanced by FEDER funds, European Union)

Quality of Life and Autonomy in Patients with Intermittent Bladder Catheterization Trained by Specialized Nurses

Intermittent bladder catheterization (IBC) involves regular urine draining using a catheter, which is removed immediately after urinary elimination. It allows for the patient's urological health to be managed and their renal function to be preserved, and it promotes autonomy. Compliance with the prescribed number of daily catheterizations, which must be conducted by the patient, and infection prevention measures are crucial. To identify the patients requiring IBC, and to determine their adherence (whether they followed the prescribed guidelines and their difficulty in carrying out the procedure, as well as to assess how the IBC influences their quality of life and state of mind after receiving self-care training from a specialized nurse), we carried out a prospective, multicenter observational study in 24 Spanish hospitals with one month of monitoring and a sample of 99 patients. The sources of information were the patients' clinical records, the King's Health Questionnaire, the Mini-Mental State Examination (MMSE), and the hospital anxiety and depression scale (HADS). Descriptive and bivariate statistics were used to analyses the paired data. After recruitment (n = 99), 79 patients completed the questionnaire at a mean age of 35.2 years (SD = 20.5 years). In total, 53.5% (53) of the sample consisted of men and 32.3% (32) had neurological damage as the reason for prescription; 67% (67.7) performed self-catheterization and 86.7% adhered to the IBC. After one month of monitoring, a statistically significant improvement in quality of life was observed in all criteria, with the exception of personal relationships (p < 0.005), as well as an improvement in anxiety and depression levels (p < 0.001). Patients who require IBC show good adherence to the IBC with a significant percentage of self-catheterization. After one month of IBC, a significant improvement in the patients' quality of life and mood was observed. These results could be attributed to adequate patient training and adequate personalization of the IBC materials by the specialized nurses

Detergent-Based Protocols on Decellularization of Corneas With Sclerocorneal Limbus. Evaluation of Regional Differences.

JOURNAL ARTICLE;PURPOSE In this work, we decellularized whole porcine corneas including the sclerocorneal limbus (SCL) and we evaluated regional differences in order to identify an efficient method to decellularize whole corneas for future clinical use. METHODS We analyzed the efficiency of four decellularization protocols based on benzalkonium chloride (BAK), Igepal, sodium dodecyl sulfate (SDS), and Triton X-100 detergents on whole porcine corneas. RESULTS Results showed that the decellularization efficiency of most protocols was low, with the specific protocol resulting in more efficient levels of decellularization being 0.1% SDS for 48 hours, especially in the medium and posterior cornea regions. A significant correlation was found between the decellularization efficiency and the concentration of agent used (P = 0.0174; r = 0.1540), but not for the incubation time (P > 0.05). The analysis of cornea components preservation demonstrated that all protocols were able to preserve the integrity of the Bowman's layer and Descemet's membrane. Although the collagen structure was partially altered, the global decellularization groups showing highest preservation of the ECM collagen contents and orientation were Igepal and SDS, with differences among the three regions of the cornea. All global groups showed high levels of proteoglycan and glycoprotein preservation after decellularization, with the best results were found in the SDS group followed by the Igepal group. CONCLUSIONS These results suggest that very powerful protocols are necessary for whole-cornea decellularization. For the generation of lamelar corneas for clinical use, decellularization regional differences should be taken into account. TRANSLATIONAL RELEVANCE Decellularized whole corneas may be potential therapeutic agents for lamelar keratoplasty.Supported by grants from the Spanish Plan Nacional de Investigación Científica, Desarrollo e Innovación Tecnológica (I+D+I) from the Spanish Ministry of Economy and Competitiveness (Instituto de Salud Carlos III), Grants FIS PI11/2680 and FIS PI11/1582 (cofinanced by FEDER funds, European Union), and by Grants PI-0462-2010 and P10-CTS-6060 from Consejería de Igualdad, Salud y Políticas Sociales and Consejería de Economía, Innovación, Ciencia y Empleo, Junta de Andalucia, Spain.Ye

Generation and characterization of an in vivo model of corneal lesion for use in tissue engineering

Objetivos: En el presente estudio se pretende generar y caracterizar un modelo lesional corneal ex vivo, con el fin de poder evaluar la viabilidad de los tejidos artificiales creados mediante Ingeniería Tisular a través de la aplicación de una causticación controlada con NaOH sobre córneas de cerdo. Métodos: Se llevó a cabo un estudio descriptivo tomando 18 ojos de cerdos adultos, inmediatamente después de morir. Los globos oculares se introdujeron en NaOH 1,5 M durante 1, 2, 3 y 5 minutos. Tras lo cual se lavaron con agua corriente (5 minutos) y se realizó un lavado rápido con PBS, seguido de un lavado de 2 minutos en PBS. Se incluyeron dos grupos control: uno de córneas no tratadas, y otro de córneas a las que se les realizó lavados de agua corriente y PBS. Las muestras fueron procesadas para el análisis histológico mediante microscopía óptica con las tinciones de hematoxilina eosina, picrosirius y azul alcian. Se determinó la significación de los resultados obtenidos mediante el análisis estadístico ANOVA. Resultados: Se observó una pérdida del endotelio y del epitelio corneal en todos los grupos tratados con NaOH. Asimismo se objetivó una tendencia a la compactación de las fibras colágenas tras el tratamiento con NaOH en la tinción de picrosirius y la pérdida de fibras de coloración verde en las muestras tratadas con NaOH con respecto a los controles. Pese a observarse una menor intensidad en la tinción de azul alcian en la región posterior con respecto a las otras dos y entre las distintas muestras tratadas con NaOH, no se encontraron diferencias significativas en este aspecto. Conclusiones: se ha logrado crear un modelo lesional sencillo, de bajo coste y que no implica problemas éticos, que permitiría evaluar los tejidos artificiales creados mediante Ingeniería Tisular.Purpose: This study aims to generate and characterize an ex vivo corneal injury model, in order to assess the feasibility of artificial tissues created by using tissue engineering through the application of a corneal alkali burn with NaOH on porcine corneas. Methods: We conducted a descriptive study taking 18 eyes of adult pigs immediately after their death. Eyes were introduced on 1.5M NaOH for 1, 2, 3 and 5 minutes. After, they were washed with running water (5 min) and rapid washing with PBS, followed by a 2 minute wash in PBS was performed. Two control groups were included: untreated corneas and another corneas were performed running water washes and PBS whashes. Samples were processed for histological analysis by light microscopy with hematoxylin and eosin, alcian blue and picrosirius staining. The significance of the results was determined by ANOVA statistical analysis. Results: We observed a loss of endothelium and the corneal epithelium in all groups treated with NaOH. A tendency to compaction of collagen fibers after treatment with NaOH and picrosirius stain loss of green coloration fibers in samples treated with NaOH with respect to controls was also observed. Despite lower intensity observed in alcian blue staining in the posterior region compared to the other two and between samples treated with NaOH, no significant differences were found in this area. Conclusions: it has created a single lesion model, low cost and does not involve ethical issues, to assess the tissue created by Tissue Engineering.Beca de Iniciación a la Investigación de la Universidad de Granad

Incidente of urinary tract infection in pregnant women and its complications

Objetivos: Estimar la incidencia de ITU en embarazadas de un centro de salud urbano que fueron estudiadas entre enero 2017 y junio 2018, detectando el germen más frecuentemente implicado y distinguiendo entre persistencia/recurrencia. Conocer las complicaciones en embarazadas derivadas de haber sufrido algún episodio de ITU. Material y método: Estudio observacional retrospectivo que se llevó a cabo en centro de salud urbano. Muestra: 79 mujeres embarazadas que tuvieron un seguimiento completo de su gestación en el centro de salud y en el periodo de tiempo indicado. Variables: Seguimiento correcto del proceso, urocultivos positivos, germen implicado, episodios de persistencia/recurrencia y complicaciones tanto no obstétricas (pielonefritis aguda (PNA)) como obstétricas (bajo peso al nacer, parto pretérmino y mortalidad perinatal). Resultados: Seguimiento correcto del proceso en un 96,2 % de embarazos. Incidencia de ITU del 14%. Germen implicado más frecuente: Escherichia coli con una incidencia mayor del 45% y Klebiella con un 27%. Aparece un episodio de persistencia de Streptococo agalactiae y una recurrencia. Un episodio de PNA, lo que supone un 9% de complicaciones. Conclusiones: Encontramos una incidencia de ITU mayor a la descrita en la literatura. Germen implicado con mayor frecuencia: Escherichia coli. Aparece una complicación por PNA sin darse complicaciones obstétricas.Objectives: To estimate the incidence of UTI in pregnant women from an urban health center who were studied between January 2017 and June 2018, detecting the germ most frequently involved and distinguishing between persistence / recurrence. To know the complications in pregnant women derived from having suffered an episode of UTI. Material and method: Retrospective observational study that took place in an urban health center. Sample: 79 pregnant women who had a complete follow-up of their pregnancy in the health center and in the period of time indicated. Variables: Correct follow-up of the process, positive urine cultures, germ implicated, episodes of persistence / recurrence and both non-obstetric complications (acute pyelonephritis (PNA)) and obstetric (low birth weight, preterm delivery and perinatal mortality). Results: Correct follow-up of the process in 96.2% of pregnancies. ITU incidence of 14%. The most frequent implicated germ: Escherichia coli with an incidence higher than 45% and Klebiella with 27%. An episode of Streptococcus agalactiae persistence and recurrence appears. An episode of ANP, which represents 9% complications. Conclusions: An incidence of UTI greater than that described in the literature was found. Germ most frequently implicated: Escherichia coli. A complication appears for PNA without obstetric complications