Anisotropic scaffold for Bone Tissue Engineering

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

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-…

Membrane porose in PLLA per la rigenerazione di mucosa bronchiale umana ottenute mediante DIPS

Galvanic Deposition of Hydroxyapatite/Chitosan/Collagen Coatings on 304 Stainless Steel

The galvanic deposition method was used to deposit Hydroxyapatite/Chitosan/Collagen coatings on 304 stainless steel. Galvanic deposition is an alternative and valid way to fabricate bio-coatings with high biocompatibility and good anticorrosion properties. Physical-chemical characterizations were carried out to investigate chemical composition and morphology of the samples. Coatings consist of a mixture of calcium phosphate (Brushite and Hydroxyapatite) with chitosan and collagen. Corrosion tests were performed in the simulated body fluid (SBF) after different aging times. Results show that, in comparison with bare 304 stainless steel, coating shifts corrosion potential to anodic values and…

Stress response and apoptosis in measoangioblast stem cells

Spectroscopic and microscopic characterization of BSA hydrogels: towards new biomaterials

Espressione basale dell’HSP70 inducibile in differenti linee staminali di topo.

An Innovative Method to Produce Scaffolds with a Pore Size Gradient for Tissue Engineering Applications

Thermally Induced Phase Separation (TIPS) is a technique for the production of porous scaffold for Tissue Engineering applications. A wide range of microporous morphologies, in terms of pore size and distribution, can be obtained by tuning TIPS processing parameters, especially thermal history. The production of scaffolds for bone tissue regeneration is a challenging target: as a matter of fact, scaffolds must mimic the bone morphology, thus requiring a gradient of pore dimension and morphology along one dimension. To attain this goal, an experimental apparatus capable to impose different thermal histories on the two sides of a sample was designed, set up and tested. The sample (35x35 mm su…

PLLA scaffolds based on thermally induced phase separation: morphology, cell seeding and proliferation

Sterilization of three-dimensional tissue engineering scaffolds by supercritical carbon dioxide

Medical devices, implants or patient-care equipment that will come into intimate contact with a patient must be effectively decontaminated to prevent infection or disease transmission. Non-sterile devices have significant ramifications for patient morbidity and mortality and two processes must be undertaken in order to make an item acceptable for use or implantation: cleaning and disinfection (or sterilization) [1]. Sterilization is the destruction of living organisms, and must be done without damaging the material surface and without compromising the bulk material strength or biocompatibility of implantable device. Common sterilization processes include steam autoclaving, gamma irradiation…

Blending PLLA with PLA so as to tune the biodegradabilty of polymeric scaffolds for soft tissue engineering

Synthesis of PLLA scaffolds for tissue engineering via phase separation

Pre-vascularized PLLA scaffolds: A new approcah to develop deep tissue regeneration

Scaffolds biodegradabili in PLLA con gradiente di porosità per rigenerazione ossea

PLLA biodegradable scaffolds for Vascular Tissue Engineering (VTE) applications via dip drawing and Diffusion Induced Phase Separation (DIPS)

Temperature influence on the morphology of porous structures prepared via Thermally Induced Phase Separation (TIPS)

PLA/PLLA scaffold for vascular tissue engineering applications

A critical obstacle encountered by tissue engineering is the inability to maintain large masses of living cells upon transfer from the in vitro culture conditions to host in vivo. Capillaries, and the vascular system, are required to supply essential nutrients, including oxygen, remove waste products and provide a biochemical communication “highway”. Another task in this research field is the possibility to tune the biodegradability of the scaffold. After implantation, the scaffold must be gradually populated by cells and replaced by extra cellular matrix; with this respect, it is crucial that this replacement takes place with appropriate dynamics and a well-defined timescale. A premature d…

PLLA scaffolds for tissue engineering prepared via thermally induced phase separation

Supercritical carbon dioxide induces sterilization of PLLA scaffolds contaminated by E. coli.

The common sterilization techniques are based on physical processes that involve, for example, the use of autoclaves or systems to radiation such as γ-rays that can cause a structural change of the polymer treated. Therefore, the use of supercritical carbon dioxide (scCO2) is an excellent alternative, as it does not induce any variation of biomaterials treated (Perrut M., 2012). It's a good candidate because is readily available at low cost, non-toxic and non-flammable, it has an easily accessible critical point (7.38 MPa and 304.2 K) and excellent transport properties and wettability (White A. et al., 2005). We report the development of a supercritical CO2 based process capable of steriliz…

Use of Modified 3D Scaffolds to Improve Cell Adhesion and Drive Desired Cell Responses.

In the most common approach of tissue engineering, a polymeric scaffold with a well-defined architecture has emerged as a promising platform for cells adhesion and guide their proliferation and differentiation into the desired tissue or organ. An ideal model for the regeneration should mimic clinical conditions of tissue injury, create a permissive microenvironment for diffusion of nutrients, gases and growth factors and permit angiogenesis. In this work, we used a 3D support made of synthetic resorbable polylactic acid (PLLA), which has considerable potential because of its well-known biocompatibility and biodegradability. One of the factors that influence cell adhesion to the scaffold is …

A6 stem cells culture into a biodegradable PLLA scaffold

Poly lactic acid based scaffolds as graft for small-diameter arterial replacement.

Vascular Tissue engineering (VTE) has emerged as a promising approach to develop blood vessel substitutes. Investigators have explored the use of arterial tissue cells combined with various types of natural and synthetic scaffolds to make tubular constructs in order to develop a functional small-diameter arterial replacement graft. The grafts must mimic the unique viscoelastic nature of an artery and be non-disruptive to blood ?ow. Moreover, after implantation, the scaffold must be gradually populated by cells and replaced by extra cellular matrix; with this respect, it is crucial that this replacement takes place with a well-defined timescale. In this work tubular scaffolds for VTE were pr…

3D cultures of primary astrocytes on Poly-L-lactic acid scaffolds

Tissue engineering is an emerging multidisciplinary field that aims at reproducing in vitro tissues with morphological and functional features similar to the biological tissue of the human body. Polymeric materials can be used in contact with biological systems in replacing destroyed tissue by transplantation [1]. Several biopolymers, including poly L (lactic acid) (PLLA), have been used in biomedical applications to set scaffolds with ductile proprieties and biodegradation kinetics [2]. In particular, the PLLA scaffold topography mimics the natural extracellular matrix and makes it a good candidate for neural tissue engineering. We report about of 3D system the PLLA porous scaffolds prepar…

POROUS SCAFFOLDS BASED ON PLLA/FUNCTIONALISED POLYMERS BLENDS PRODUCED BY THERMALLY INDUCED PHASE SEPARATION

Synthesis of a porous and biodegradable PLLA scaffold for application of tissue engineering

Analisi dell’espressione dell’HSP70 inducubile in cellule staminali ed in tessutiu adulti di topo.

Migration of brain capillary endothelial cells inside poly (lactic acid) 3D scaffolds

The brain capillary endothelial cells (BCECs) form the blood brain barrier (BBB) under the effects of the brain microenvironment. BCECs are sealed together by tight junctions (TJs) that are responsible for the barrier phenotype. In these junctions, molecules such as JAM (junctional adhesion molecules), occludin and claudins are present. Threedimensional scaffolds are used to grow cells in order to obtain in vitro engineered tissues. On the base of these considerations, the aim of this work was to understand whether the endothelial cells were able to grow and survive on a new three-dimensional structure. If yes, indeed, this system could be further enriched and used to set a three-dimensiona…

An Innovative Method to Produce Scaffolds with a Pore Size Gradient for Tissue Engineering

Preparation and characterization of PLLA-HA scaffolds for bone tissue engineering

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 …

Porous PLLA scaffolds are optimal substrates for internal colonization by A6 mesoangioblasts and immunocytochemical analyses

In the present paper, mouse mesoangioblasts were seeded onto bidimensional matrices and within three-dimensional porous scaffolds of poly(L-lactic acid) (PLLA), in the presence or absence of type I collagen coating, observed under the scanning electron microscope, and tested for their adhesion, survival and proliferation. Immunolocalization of Hsp70, an abundant and ubiquitous intracellular protein in these cells, was also performed in sectioned cell-containing scaffolds under the confocal fluorescence microscope to check whether "in situ" analysis of intracellular constituents was feasible. The data obtained show that PLLA films allow direct cell adhesion and represent an optimal support f…

Galvanic Deposition of Calcium Phosphate/Bioglass Composite Coating on AISI 316L

Calcium phosphate/Bioglass composite coatings on AISI 316L were investigated with regard to their potential role as a beneficial coating for orthopedic implants. These coatings were realized by the galvanic co-deposition of calcium phosphate compounds and Bioglass particles. A different amount of Bioglass 45S5 was used to study its effect on the performance of the composite coatings. The morphology and chemical composition of the coatings were investigated before and after their aging in simulated body fluid. The coatings uniformly covered the AISI 316L substrate and consisted of a brushite and hydroxyapatite mixture. Both phases were detected using X-ray diffraction and Raman spectroscopy.…

Microscopic evidence of the primary astrocytes' morphological differentiation and migration inside porous Poly-L-lactic acid 3D‑scaffolds

Tissue engineering is an emerging multidisciplinary field that aims at reproducing in vitro and/or in vivo tissues with morphological and functional features similar to the biological tissue of the human body [1]. In the attempt to construct suitable tissue models, a critical step is the setting of 3D scaffolds that mimic the supportive structures of a natural extracellular matrix microenvironment into which cells are normally embedded. In this context, the generation of 3D cultures of brain cells is of particular interest. For instance, the poly L‐lactic acid (PLLA) polymer is wildly used because of its biocompatible and biodegradable potential; the PLLA scaffold topography simulates the n…

Composites poly-lactic acid - hydroxyapatite scaffolds prepared via Thermally Induced Phase Separation

Membrane biodegradabili in PLLA preparate mediante DIPS (Diffusion Induced Phase Separation) come supporto per la rigenerazione di mucosa bronchiale umana

PREPARATION AND HYDROLYTIC DEGRADATION OF POLY LACTIC ACID BASED SCAFFOLDS

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The use of Diffusion Induced Phase Separation (DIPS) technique for the preparation of biodegradable scaffolds for angiogenesis

Tissue engineered vascular grafts based on poly-lactic acid blends

A great deal of research has been pursued in the last decade with the goal of developing blood vessel substitutes. Tissue engineering has emerged as a promising approach to address the shortcomings of current options. One of the major tasks in this research field is the possibility to tune the biodegradability of the implantable devices (scaffolds). After implantation, the scaffold has to be replaced by extra cellular matrix; with this respect, it is crucial that this replacement takes place with appropriate dynamics and a well-defined timescale. In this work tissue-engineered vascular graft were produced, utilizing several PLLA/PLA blends (100/0, 90/10, 75/25 wt/wt) in order to tune their …