Effect of extrace llular matrix and dental pulp stem cells on bone regeneration with 3D printed PLA/HA composite scaffolds /

The demand for bone grafting procedures in various fields of medicine is increasing. Existing substitutes in clinical practice do not meet all the criteria required for an ideal bone scaffold, so new materials are being sought. This study evaluated bone regeneration using a critical-size Wistar rat’s calvarial defect model. 12 male and 12 female rats were evenly divided into 3 groups: 1. Negative and positive (Geistlich Bio-Oss®) controls; 2. polylactic acid (PLA) and PLA/hydroxyapatite (HA); 3. PLA/HA cellularised with dental pulp stem cells (DPSC) and PLA/HA extracellular matrix (ECM) scaffolds. PLA/HA filament was created using hot-melt extrusion equipment. All scaffolds were fabricated using a 3D printer. DPSC were isolated from the incisors of adult Wistar rats. The defects were evaluated by micro-computed tomography (µCT) and histology, 8 weeks after surgery. µCT revealed that the Bio-Oss group generated 1.49 mm3 and PLA/HA ECM 1.495 mm3 more bone volume than the negative control. Histology showed a statistically significant difference between negative control and both (Bio-Oss and PLA/HA ECM) groups in rats of both genders. Moreover, histology showed gender-specific differences in all experimental groups and a statistically significant difference between cellularised PLA/HA and PLA/HA ECM groups in female rats. Qualitative histology showed the pronounced inflammation reaction during biodegradation in the PLA group. In conclusion, the bone-forming ability was comparable between the Bio-Oss and PLA/HA ECM scaffolds. Further research is needed to analyse the effects of ECM and PLA/HA ratio on osteoregeneration

Mejora del dolor crónico en ratones con sobrepeso tras la administración de un prebiótico

Resumen trabajo presentado en el XII Workshop Sociedad Española de Microbiota, Probióticos y Prebióticos (SEMiPyP) y I Congreso Sociedad Iberoamericana de Microbiota, Probióticos y Prebióticos (SIAMPYP), celebrado de forma virtual del 15 al 18 de septiembre de 2021Introducción/Objetivo. El sobrepeso y la obesidad son problemas graves de salud pública, con alto riesgo de mortalidad y comorbilidades asociadas. El dolor crónico es más frecuente y severo en estos individuos, por lo que existe una necesidad de buscar terapias que ayuden a mitigarlo. La microbiota intestinal (MI) juega un papel crítico en la salud, y a través del eje intestino-cerebro ejerce funciones a nivel del sistema nervioso, por lo que se ha propuesto como una diana de actuación en trastornos metabólicos y/o neurológicos. Los prebióticos son conocidos por su efecto modulador de la MI. En este trabajo, el objetivo fue evaluar el efecto de un prebiótico en el desarrollo del dolor crónico inducido por el sobrepeso en un modelo animal. Metodología. Cuatro grupos de ratones macho C57Bl6/J (n= 10/grupo) recibieron dos tipos de dieta: 2 grupos dieta hipercalórica (HFD) y 2 grupos dieta control (CD). Un grupo de cada condición fue administrado con un prebiótico en el agua de bebida durante la duración del experimento (8 semanas). Se evaluó el desarrollo de alodinia mecánica e hiperalgesia térmica con diferentes pruebas in vivo, se realizaron análisis bioquímicos y se analizó la MI mediante secuenciación del gen ribosómico 16S. Resultados. La HFD indujo sobrepeso y desarrollo de dolor crónico en los ratones. La administración del prebiótico atenuó el peso corporal, tuvo efectos positivos sobre hormonas metabólicas y redujo el desarrollo del dolor inducido por el sobrepeso. La composición de la MI se vio alterada por la HFD y modulada por el prebiótico. Algunos grupos microbianos se asociaron con una menor respuesta al dolor. Conclusiones. Los resultados muestran el efecto positivo de los prebióticos en el desarrollo del dolor inducido por el sobrepeso, pudiendo actuar la MI como mediador. Este trabajo fortalece el papel de la MI como diana de actuación para mejorar trastornos metabólicos del eje intestino-cerebro

Targeting the Microbiota-Gut-Brain Axis for obesity-induced chronic pain

Trabajo presentado en la 13th International Scientific Conference on Probiotics, Prebiotics, Gut Microbiota and Health, celebrado en Praga (República Checa), del 17 al 20 de junio de 2019[Introduction] Obesity is a global epidemic and is associated with increased risk for mortality and several medical morbidities that create a substantial burden on both the aƿicted patients and society. Chronic pain is more frequent and severe among overweight patients and given the enormity of the problem and the lack of effective therapies, there is a pressing need to understand the mechanisms underlying pain development under these particular conditions. Multiple studies have now revealed that the microbiota-gut-brain axis plays a critical role in health and disease. In agreement, modulation of the gut microbiota via probiotic treatment is postulated to be an effective adjunctive therapy for metabolic disorders. In contrast, the role of prebiotics is less investigated. Prebiotic Ƽbres like short-chain fructo-oligosaccharides (FOS) are known to selectively modulate the composition of the intestinal microbiota and specially to stimulate proliferation of the lactobacilli and biƼdobacteria in the gut. [Methods] A model of overweight-induced exposure chronic pain was used in this study. Mice (40 C57Bl6/J male) were randomly assigned to the different diets for an entire period of 8 weeks: hypercaloric high-fat diet (5.21 kcal/g) and control diet (3.87 kcal/g). We tested whether the prebiotic FOS, which increases intrinsic enteric microbiota, affected obesity-induced chronic pain development. Mice were exposed to by exposing the animals to drinking water containing or not FOS during the entire experimental period. The development of allodynia and hyperalgesia were evaluated by using the von Frey and the plantar tests, respectively. Plasma leptin, adiponectin and insulin were measured. Cecum microbiota composition was determined. [Results] High fat diet induced overweight and the development of chronic pain in mice, revealed in the von Frey test. The administration of FOS attenuated body weight and epididymal fat gain and revealed reduced obesity-induced pain development. The prebiotic increased the weight of he cecum and had a positive effect on metabolic hormones such as leptin, insulin and adiponectin. Microbiota composition was also affected by diet and by FOS administration. High-fat diet reduced microbiota diversity and the presence of Roseburia was associated with reduced pain response. [Discussion] These data show that FOS produced a positive impact on obesity-induced pain development in mice. Collectively, our results suggest that prebiotics can ameliorate the overall metabolic proƼle of mice exposed to high-fat diet, partly by acting on the gut microbiota. Future studies in animal models of disease and in humans are now warranted. These Ƽndings strengthen the role of gut microbiota supplementation as prebiotic-based strategies for metabolic related brain-gut axis disorders opening new avenues in the Ƽeld of neurogastroenterology and nutritional neuroscience

Biocompatibility investigation of hybrid organometallic polymers for sub-micron 3D printing via laser two-photon polymerisation

Hybrid organometallic polymers are a class of functional materials which can be used to produce structures with sub-micron features via laser two-photon polymerisation. Previous studies demonstrated the relative biocompatibility of Al and Zr containing hybrid organometallic polymers in vitro. However, a deeper understanding of their effects on intracellular processes is needed if a tissue engineering strategy based on these materials is to be envisioned. Herein, primary rat myogenic cells were cultured on spin-coated Al and Zr containing polymer surfaces to investigate how each material affects the viability, adhesion strength, adhesion-associated protein expression, rate of cellular metabolism and collagen secretion. We found that the investigated surfaces supported cellular growth to full confluency. A subsequent MTT assay showed that glass and Zr surfaces led to higher rates of metabolism than did the Al surfaces. A viability assay revealed that all surfaces supported comparable levels of cell viability. Cellular adhesion strength assessment showed an insignificantly stronger relative adhesion after 4 h of culture than after 24 h. The largest amount of collagen was secreted by cells grown on the Al-containing surface. In conclusion, the materials were found to be biocompatible in vitro and have potential for bioengineering applications

3D microporous scaffolds manufactured via combination of fused filament fabrication and direct laser writing ablation

A 3D printing fused filament fabrication (FFF) approach has been implemented for the creation of microstructures having an internal 3D microstructure geometry. These objects were produced without any sacrificial structures or additional support materials, just by precisely tuning the nozzle heating, fan cooling and translation velocity parameters. The manufactured microporous structures out of polylactic acid (PLA) had fully controllable porosity (20%-60%) and consisted of desired volume pores (similar to 0.056 mu m(3)). The prepared scaffolds showed biocompatibility and were suitable for the primary stem cell growth. In addition, direct laser writing (DLW) ablation was employed to modify the surfaces of the PLA structures, drill holes, as well as shape the outer geometries of the created objects. The proposed combination of FFF printing with DLW offers successful fabrication of 3D microporous structures with functionalization capabilities, such as the modification of surfaces, the generation of grooves and microholes and cutting out precisely shaped structures (micro-arrows, micro-gears). The produced structures could serve as biomedical templates for cell culturing, as well as biodegradable implants for tissue engineering. The additional micro-architecture is important in connection with the cell types used for the intention of cell growing. Moreover, we show that surface roughness can be modified at the nanoscale by immersion into an acetone bath, thus increasing the hydrophilicity. The approach is not limited to biomedical applications, it could be employed for the manufacturing of bioresorbable 3D microfluidic and micromechanic structures