Search results for "phase separation"

Evidence of Mechanisms Occurring in Thermally Induced Phase Separation of Polymeric Systems

2014

Thermally induced phase separation is a fabrication technique for porous polymeric structures. By means of easy-to-tune processing parameters, such as system composition and demixing temperature, a vast latitude of average pore dimensions, pore size distributions, and morphologies can be obtained. The relation between demixing temperature and morphology was demonstrated via cloud point curve measurement and foams fabrication with controlled thermal protocols, for the model system poly-l-lactide–dioxane–water. The morphologies obtained at a temperature lower than cloud point showed a closed-pore architecture, suggesting a “nucleation-and-growth” separation mechanism, which produced larger po…

Exploring Bioequivalence of Dexketoprofen Trometamol Drug Products with the Gastrointestinal Simulator (GIS) and Precipitation Pathways Analyses

2019

The present work aimed to explain the differences in oral performance in fasted humans who were categorized into groups based on the three different drug product formulations of dexketoprofen trometamol (DKT) salt&mdash

A Poly-L-Lactide scaffold with continuous gradient pore size for osteochondral regeneration validated in a microphysiological tissue system bioreactor

2016

A microphysiological tissue system (MPS) bioreactor has been developed to replicate in vitro the in vivo OC physiological conditions. The MPS allows separate control of the chondral and osseous environment while permitting communication between chondrocytes and osteoblasts across the OC junction, similar to the conditions of OC tissue in vivo. We have used here our MPS system to validate the TIPS -generated pore-gradient PLLA scaffold.

Editorial: The Role of Protein Post-Translational Modifications in Protein-RNA Interactions and RNP Assemblies

2022

Preparation of polymeric foams with a pore size gradient via Thermally Induced Phase Separation (TIPS)

2015

Abstract Foams with a pore size gradient are promising materials for tissue engineering applications where a complex architecture involving morphological variations in space must be mimicked, e.g. in bone tissue repair. In this paper, a technique to obtain a porous scaffold with a pore size gradient is presented. The preparation procedure is based on Thermally Induced Phase Separation (TIPS), by imposing a different thermal history on the two sides of a polymeric solution. In this way, a gradient in thermal history is produced, which will generate a pore size monotonously varying along scaffold thickness. By controlling some parameters easy to manipulate, such as demixing temperature and/or…

A COMPOSITE PLLA SCAFFOLD FOR REGENERATION OF COMPLEX TISSUES

2010

A composite biodegradable scaffold incorporating an integrated network of synthetic blood vessels was designed and prepared, in line with the requirements of a scaffold effectively supporting the regeneration of highly vascularized tissues. In other words, this composite scaffold should allow the regeneration of complex injured tissue (e.g. dermis) and, at the same time, favour the development of a vascular network on its inner, i.e. a 3D polymeric scaffolds embedding synthetic blood vessel-like structures for nutrient supply and metabolite removal. PLLA assures a high degree of biocompatibility and a low level of inflammation response upon implantation, while the embedded tubular vessel-li…

Modeling and experimental approaches for the characterization of phase equilibria in polymer solutions

2012

Polyactide Biodegradable Scaffolds for Tissue Engineering Applications: Phase Separation-Based Techniques

2011

One of the most reliable techniques for the preparation of biodegradable scaffolds suitable for tissue engineering applications (e.g. regeneration of wounded/damaged tissues) is based on liquid/liquid phase separation of ternary solvent/antisolvent/polymer solutions. In particular, two phase separation protocols are examined here: Thermally Induced Phase Separation (TIPS) and Diffusion Induces Phase Separation (DIPS). According to the former protocol, a thermodynamically stable polymeric ternary solution is brought below its metastability/instability point (spinodal/binodal curve) by quench in a cooling medium: under opportune conditions, a foam-like structure is formed by nucleation and 3-…

Theoretical Predictions and experimental determination of cloud point curves for polymeric solutions: an application to the ternary system Poly-lacti…

2011

The lattice fluid model with specific interactions was applied to the ternary system Poly-L-lactic-acid (PLLA)-dioxane-water. Model parameters were determined by fitting experimental data. The as-obtained parameters were used to calculate the complete phase diagram. An experimental apparatus for cloud point measurements, which is under construction, is presented.

The cell nucleus. A study in Burgundy

2019

ABSTRACT Wilhelm Bernhard’s revolutionary microscopy techniques helped him put forward the hypothesis of specialized compartmentalization of the nucleus. He also described for the first time the nuclear bodies and peri-chromatin fibrils, and demonstrated that these granules contain an RNA component. The tradition of biennial workshops, named after this great scientist, continues, and this year it took place in the heart of Burgundy, in Dijon, France (May 20–24, 2019, organized by INSERM UMR1231, UBFC), where well-fed participants emphasized the importance of viewing the cell nucleus as a hub of specialized colloidal compartments that orchestrate replication, transcription and nuclear transp…