Towards a New Concept of Regenerative Endodontics Based on Mesenchymal Stem Cell-Derived Secretomes Products.

The teeth, made up of hard and soft tissues, represent complex functioning structures of the oral cavity, which are frequently affected by processes that cause structural damage that can lead to their loss. Currently, replacement therapy such as endodontics or implants, restore structural defects but do not perform any biological function, such as restoring blood and nerve supplies. In the search for alternatives to regenerate the dental pulp, two alternative regenerative endodontic procedures (REP) have been proposed: (I) cell-free REP (based in revascularization and homing induction to remaining dental pulp stem cells (DPSC) and even stem cells from apical papilla (SCAP) and (II) cell-based REP (with exogenous cell transplantation). Regarding the last topic, we show several limitations with these procedures and therefore, we propose a novel regenerative approach in order to revitalize the pulp and thus restore homeostatic functions to the dentin-pulp complex. Due to their multifactorial biological effects, the use of mesenchymal stem cells (MSC)-derived secretome from non-dental sources could be considered as inducers of DPSC and SCAP to completely regenerate the dental pulp. In partial pulp damage, appropriate stimulate DPSC by MSC-derived secretome could contribute to formation and also to restore the vasculature and nerves of the dental pulp.

Cost-effective fabrication of photopolymer molds with multi-level microstructures for PDMS microfluidic device manufacture.

This paper describes a methodology of photopolymer mold fabrication with multi-level microstructures for polydimethylsiloxane (PDMS) microfluidic device manufacture. Multi-level microstructures can be performed by varying UVA exposure time and channel width. Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM) and profilometry techniques have been employed to characterize the molds. Multiple molds with multi-level microstructures can be formed in a unique piece. Overall height/depth of the structures reaches up to 677 µm and a minimum of 21 µm. The method provides several advantages such as reduction of fabrication time, multiple structures with diverse topologies, a great variety of depth and height in a single mold and low cost of fabrication. The effectiveness of multi-level microstructure fabrication was evaluated by constructing PDMS microfluidic devices for cell culture and proliferation.

Microencapsulación de aceite de sacha inchi (Plukenetia volubilis L.) mediante secado por aspersión / Microencapsulation of oil sacha inchi (Plukenetia volubilis L.) by spray drying

El objetivo de esta investigación fue microencapsular aceite de sacha inchi mediante secado por aspersión, con el fin de evitar las reacciones oxidativas de degradación, dado su alto contenido de ácidos grasos monoinsaturados y poliinsaturados, los cuales presentan grandes beneficios para la salud. Empleando maltodextrina y goma arábiga en una proporción ( 1:1 ), se evaluó la temperatura de entrada y la carga de aceite, siendo 150 °C y 33% las mejores condiciones de trabajo durante el proceso de secado. Se obtuvo un rendimiento y eficiencia de microencapsulación de 82,10 ± 0,99% y 93,90 ± 0,56%, respectivamente. Cabe mencionar que esta investigación es la primera en emplear la técnica de secado por aspersión, y como agentes formadores de la pared polimérica la mezcla de maltodextrina y goma arábiga en la microencapsulación de aceite de sacha inchi. Mediante análisis fisicoquímico, se evaluó la humedad del aceite de sacha inchi microencapsulado, manteniendo un contenido de humedad a las 26 semanas de 4,60 ± 0,02%. Al utilizar cromatografía de gases se encontró que no existe variación en cuanto al perfil de ácidos grasos antes y después de la microencapsulación, y mediante espectroscopía infrarroja se demostró que el aceite de sacha inchi se encuentra en el interior de las microcápsulas. La microscopía electrónica de barrido permitió observar que las microcápsulas presentan forma esférica con una superficie lisa y libre de poros, lo que evita la exposición directa del aceite a las diferentes condiciones ambientales.

The objective of this research was microencapsulated sacha inchi oil by spray drying, in order to prevent oxidative degradation reactions, given its high content of mono-unsaturated and polyunsaturated fatty acids, which present great health benefits. Employing a maltodextrin-gum arabic system in the same ratio (1:1), the inlet temperature and the oil charge was evaluated, being 150 °C and 33% the best conditions during the drying process, obtaining a performance and efficiency microencapsulation of 82.10 ± 0.99% and 93.90 ± 0.56%, respectively. It should be mentioned that this research is the first one to use the spray drying technique and maltodextrin and arabic gum as polymeric wall formers agents for the sacha inchi oil microen-capsulation. By physicochemical analysis, the microencapsulated sacha inchi oil moisture was evaluated, keeping a moisture content at 26 weeks of 4.60 ± 0.02%, applying gas chromatography, it was found that there is no variation in the fatty acid profile before and after microencapsulation. Through infrared spectroscopy it was shown that sacha inchi oil is inserted into the core of the microcapsules. The electron microscopy scanning allowed to observe that the microcapsules have a spherical shape with a smooth surface and free of pores which prevent direct contact of the oil with different ambient conditions.