Three-Dimensional Bioprinted Controlled Release Scaffold Containing Mesenchymal Stem/Stromal Lyosecretome for Bone Regeneration: Sterile Manufacturing and In Vitro Biological Efficacy

Recently, 3D-printed scaffolds for the controlled release of mesenchymal stem cell (MSC) freeze-dried secretome (Lyosecretome) have been proposed to enhance scaffold osteoinduction and osteoconduction; coprinting of poly(ε-caprolactone) (PCL) with alginate hydrogels allows adequate mechanical strength to be combined with the modulable kinetics of the active principle release. This study represents the feasibility study for the sterile production of coprinted scaffolds and the proof of concept for their in vitro biological efficacy. Sterile scaffolds were obtained, and Lyosecretome enhanced their colonization by MSCs, sustaining differentiation towards the bone line in an osteogenic medium. Indeed, after 14 days, the amount of mineralized matrix detected by alizarin red was significantly higher for the Lyosecretome scaffolds. The amount of osteocalcin, a specific bone matrix protein, was significantly higher at all the times considered (14 and 28 days) for the Lyosecretome scaffolds. Confocal microscopy further confirmed such results, demonstrating improved osteogenesis with the Lyosecretome scaffolds after 14 and 28 days. Overall, these results prove the role of MSC secretome, coprinted in PCL/alginate scaffolds, in inducing bone regeneration; sterile scaffolds containing MSC secretome are now available for in vivo pre-clinical tests of bone regeneration

A self-organized synthetic morphogenic liposome responds with shape changes to local light cues

Reconstituting artificial proto-cells capable of transducing extracellular signals into cytoskeletal changes can reveal fundamental principles of how non-equilibrium phenomena in cellular signal transduction affect morphogenesis. Here, we generated a Synthetic Morphogenic Membrane System (SynMMS) by encapsulating a dynamic microtubule (MT) aster and a light-inducible signaling system driven by GTP/ATP chemical potential into cell-sized liposomes. Responding to light cues in analogy to morphogens, this biomimetic design embodies basic principles of localized Rho-GTPase signal transduction that generate an intracellular MT-regulator signaling gradient. Light-induced signaling promotes membrane-deforming growth of MT-filaments by dynamically elevating the membrane-proximal tubulin concentration. The resulting membrane deformations enable recursive coupling of the MT-aster with the signaling system, which generates global self-organized morphologies that reorganize towards local external cues in dependence on prior shape. SynMMS thereby signifies a step towards bio-inspired engineering of self-organized cellular morphogenesis

Microempresarios de la guadua en el sector artesanal del Eje Cafetero colombiano

El tejido empresarial colombiano se caracteriza por las microempresas. En esta investigación se pretendió identificar los apoyos que las microempresas que trabajan con la guadua en el sector artesanal, reciben por parte de los entes para su inicio de actividades y supervivencia. Para lograr este objetivo iniciamos con una investigación documental derivada de escritos, bases de datos, entidades de apoyo, informes especializados sobre el sector y el tejido empresarial colombiano. Después recolectamos y analizamos la información obtenida de las entrevistas semiestructuradas aplicadas a una muestra de la población artesanal de la región. Esta investigación se desarrolla en el Eje Cafetero colombiano, una zona rica en guadua: una de las regiones que cuenta con el mayor número de artesanos del país. Indagamos sobre los entes institucionales que otorgan apoyos, desde los aspectos regionales, académicos, financieros, económicos y de otro tipo, para fortalecer el sector de la guadua. Se percibe la necesidad de impulsar el aspecto formativo como uno de los más importantes para desarrollar las unidades productivas. También se evidencia poco apoyo constante para los artesanos, al igual que falta de unión por parte de los actores que acogen al sector, lo que no permite una coherencia entre sus objetivos y lo que realmente se hace. El subsector no se encuentra muy articulado y la formación a nivel empresarial se hace necesaria para la apropiación de habilidades que les permitan tener una visión más amplia y estratégica del negocio

Experimental Investigation on the Effects of Cooled Low Pressure EGR and Water Injection on Combustion of a Turbocharged GDI Engine

This work focuses on the effects of cooled Low Pressure EGR and Water Injection observed by conducting experimental tests consisting mainly of Spark Advance sweeps at different cooled LP-EGR and WI rates. The implications on combustion and main engine performance indexes are then analysed and modelled with a control-oriented approach, showing that combustion duration and phase and exhaust gas temperature are the main affected parameters. Results show that cooled LP-EGR and WI have similar effects, being the associated combustion speed decrease the main cause of exhaust gas temperature reduction. Experimental data is used to identify control-oriented polynomial models able to capture the effects of LP-EGR and WI on both these aspects. The limitations of LP-EGR are also explored, identifying maximum compressor volumetric flow and combustion stability as the main ones. The potential synergy of using both LP-EGR and WI is investigated by performing EGR and WI sweeps both separately and simultaneously, observing that their effects can be mainly considered additive

Experimental characterization and computational modeling of hydrogel cross-linking for bioprinting applications

Alginate-based hydrogels are extensively used to create bioinks for bioprinting, due to their biocompatibility, low toxicity, low costs, and slight gelling. Modeling of bioprinting process can boost experimental design reducing trial-and-error tests. To this aim, the cross-linking kinetics for the chemical gelation of sodium alginate hydrogels via calcium chloride diffusion is analyzed. Experimental measurements on the absorbed volume of calcium chloride in the hydrogel are obtained at different times. Moreover, a reaction-diffusion model is developed, accounting for the dependence of diffusive properties on the gelation degree. The coupled chemical system is solved using finite element discretizations which include the inhomogeneous evolution of hydrogel state in time and space. Experimental results are fitted within the proposed modeling framework, which is thereby calibrated and validated. Moreover, the importance of accounting for cross-linking-dependent diffusive properties is highlighted, showing that, if a constant diffusivity property is employed, the model does not properly capture the experimental evidence. Since the analyzed mechanisms highly affect the evolution of the front of the solidified gel in the final bioprinted structure, the present study is a step towards the development of reliable computational tools for the in silico optimization of protocols and post-printing treatments for bioprinting applications

T-Shape Professionals Co-working in Smart Contexts: VEGA(ST) – Venice Gateway for Science and Technology

The places where people routinely gather to interact and work can be thought of as territories with boundaries that provide a smart context to achieve personal and professional goals. For example, the Venice Gateway for Science and Technology of VEGA(ST) is such a smart context, in the form of a co-working space. In this paper, smart contexts are explored using the integrated framework of Service Science, Management Engineering, Design Arts Public Policy (SSME +DAPP) and the Viable Systems Approach (VSA) research methods, which encourage the development of T-shaped professionals with depth and breadth. We explore the importance of: (1) adopting a win-win logic between the external environment and the resource holders of the wider enterprise-territory system, (2) the creation of smart contexts, as a symbol of sharing, where interaction and actor involvement facilitate the co-creation of value for the collective welfare, and (3) co-working spaces as a way to encourage T-shape professionals to develop their broad dynamic capabilities and their in depth competencies