Search results for "phase separation"
showing 10 items of 62 documents
POROUS SCAFFOLDS BASED ON PLLA/FUNCTIONALISED POLYMERS BLENDS PRODUCED BY THERMALLY INDUCED PHASE SEPARATION
2014
Solution-Based Processing for Scaffold Fabrication in Tissue Engineering Applications: A Brief Review
2021
The fabrication of 3D scaffolds is under wide investigation in tissue engineering (TE) because of its incessant development of new advanced technologies and the improvement of traditional processes. Currently, scientific and clinical research focuses on scaffold characterization to restore the function of missing or damaged tissues. A key for suitable scaffold production is the guarantee of an interconnected porous structure that allows the cells to grow as in native tissue. The fabrication techniques should meet the appropriate requirements, including feasible reproducibility and time- and cost-effective assets. This is necessary for easy processability, which is associated with the large …
Synthesis, characterization and foaming of PHEA-PLLA, a new graft copolymer for biomedical engineering
2014
Abstract In this study a chemical grafting procedure was set up in order to link high molecular weight poly L-lactic acid (PLLA) chains to the hydrophilic α,β-poly(N-2-hydroxyethyl)-DL-aspartamide (PHEA) backbone. A graft copolymer named PHEA-g-PLLA (or simply PHEA–PLLA) was obtained bearing a degree of derivatization of 1.0 mol.% of PLLA as grafted chain. This new hybrid derivative offers both the opportune crystallinity necessary for the production of scaffolds trough a thermally induced phase separation (TIPS) technique and the proper chemical reactivity to perform further functionalizations with bio-effectors and drugs. PHEA–PLLA porous scaffolds for tissue engineering applications were…
Preparation and characterization of PLLA-HA scaffolds for bone tissue engineering
2013
In this work, the possibility to produce composite - Poly-L-lactic acid (PLLA) and Hydroxyapatite (HA) - porous scaffolds via Thermally Induced Phase Separation for bone tissue engineering applications was investigated. Several PLLA/HA ratios were tested (70/30, 50/50, 30/70 and 20/80 wt/wt) and the as-obtained scaffolds were characterized via Scanning Electron Microscopy (SEM), Wide Angle X-Ray Diffraction (WAXD) and compression test. The results showed that the presence of HA does not influence the phase separation process. Morphological analysis revealed an open structure with interconnected pores and HA embedded in the polymer matrix. This evidence was confirmed by WAXD analysis; where …
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…
Poly lactic acid based foams prepared via thermally induced phase separation (TIPS): A method to tune the crystallinity
2012
Blends of Poly-L-Lactic Acid (PLLA) with two Poly-Lactic Acid (PLA) in different proportions (90/10 and 70/30) were utilized in order to produce biodegradable and biocompatible scaffolds for soft tissue engineering applications. The scaffolds were produced via thermally induced phase separation (TIPS) starting from ternary systems where dioxane was the solvent and water the non-solvent. Morphology was evaluated by Scanning Electron Microscopy (average pore size and interconnection). Moreover a DSC analysis was carried out on the as-obtained scaffold in order to obtain information about theirs thermal properties (enthalpy of melt and crystallization). The results showed that is possible to p…
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.
Poly-left-lactic acid tubular scaffolds via diffusion induced phase separation: Control of morphology
2013
n this work, tubular poly-left-lactic acid scaffolds for vascular tissue engineering applications were produced by an innovative two-step method. The scaffolds were obtained by performing a dip-coating around a nylon fiber, followed by a diffusion induced phase separation process. Morphological analysis revealed that the internal lumen of the as-obtained scaffold is equal to the diameter of the fiber utilized; the internal surface is homogeneous with micropores 1–2 μm large. Moreover, a porous open structure was detected across the thickness of the walls of the scaffold. An accurate analysis of the preparation process revealed that it is possible to tune up the morphology of the scaffold (w…