Search results for "Tissue scaffold"
showing 10 items of 140 documents
Hyaluronic Acid Derivative with Improved Versatility for Processing and Biological Functionalization
2016
A hydrophobic/amino functionalized derivative of hyaluronic acid (HA-EDA-C18 ) has been processed by salt leaching technique as porous scaffold without need of chemical crosslinking. Aim of this work is to demonstrate the improved versatility of HA-EDA-C18 in terms of processing and biological functionalization. In particular, the chemical procedure to tether thiol bearing RGD peptide has been described. Moreover, the possibility to load and to control the release of slightly water soluble effectors has been demonstrated by using dexamethasone. First, the swelling and degradation profiles of the scaffolds have been investigated, then the evaluation of metabolic activity of bovine chondrocyt…
Poly-l-Lactic Acid Nanofiber-Polyamidoamine Hydrogel Composites: Preparation, Properties, and Preliminary Evaluation as Scaffolds for Human Pluripote…
2016
Electrospun poly-l-lactic acid (PLLA) nanofiber mats carrying surface amine groups, previously introduced by nitrogen atmospheric pressure nonequilibrium plasma, are embedded into aqueous solutions of oligomeric acrylamide-end capped AGMA1, a biocompatible polyamidoamine with arg-gly-asp (RGD)-reminiscent repeating units. The resultant mixture is finally cured giving PLLA-AGMA1 hydrogel composites that absorb large amounts of water and, in the swollen state, are translucent, soft, and pliable, yet as strong as the parent PLLA mat. They do not split apart from each other when swollen in water and remain highly flexible and resistant, since the hydrogel portion is covalently grafted onto the …
Degradable poly(amidoamine) hydrogels as scaffolds for in vitro culturing of peripheral nervous system cells.
2012
This paper reports on the synthesis and physico-chemical, mechanical, and biological characterization of two sets of poly(amidoamine) (PAA) hydrogels with potential as scaffolds for in vivo peripheral nerve regeneration. They are obtained by polyaddition of piperazine with N,N′-methylenebis(acrylamide) or 1,4-bis(acryloyl)piperazine with 1,2-diaminoethane as cross-linking agent and exhibit a combination of relevant properties, such as mechanical strength, biocompatibility, biodegradability, ability to induce adhesion and proliferation of Schwann cells (SCs) preserving their viability. Moreover, the most promising hydrogels, that is those deriving from 1,4-bis(acryloyl)piperazine, allow the …
Mesenchymal stem cell proliferation and differentiation on load-bearing trabecular Nitinol scaffolds.
2013
Bone tissue regeneration in load-bearing regions of the body requires high-strength porous scaffolds capable of supporting angiogenesis and osteogenesis. 70% porous Nitinol (NiTi) scaffolds with a regular 3-D architecture resembling trabecular bone were produced from Ni foams using an original reactive vapor infiltration technique. The "trabecular Nitinol" scaffolds possessed a high compressive strength of 79 MPa and high permeability of 6.9×10(-6) cm2. The scaffolds were further modified to produce a near Ni-free surface layer and evaluated in terms of Ni ion release and human mesenchymal stem cell (hMSC) proliferation (AlamarBlue), differentiation (alkaline phosphatase activity, ALP) and …
Preparation of three-layered porous PLA/PEG scaffold: relationship between morphology, mechanical behavior and cell permeability.
2015
Interface tissue engineering (ITE) is used to repair or regenerate interface living tissue such as for instance bone and cartilage. This kind of tissues present natural different properties from a biological and mechanical point of view. With the aim to imitating the natural gradient occurring in the bone-cartilage tissue, several technologies and methods have been proposed over recent years in order to develop polymeric functionally graded scaffolds (FGS). In this study three-layered scaffolds with a pore size gradient were developed by melt mixing polylactic acid (PLA) and two water-soluble porogen agents: sodium chloride (NaCl) and polyethylene glycol (PEG). Pore dimensions were controll…
Scaffolds based on hyaluronan crosslinked with a polyaminoacid: Novel candidates for tissue engineering application
2008
New porous scaffolds, with a suitable hydrolytic and enzymatic degradation, useful for tissue engineering applications have been obtained by a carbodiimide mediated reaction between hyaluronan (HA) and a synthetic polymer with a polyaminoacid structure such as α,β-polyaspartylhydrazide (PAHy). Scaffolds with a different molar ratio between PAHy repeating units and HA repeating units have been prepared and characterized from a chemical and physicochemical point of view. Tests of indirect and direct cytotoxicity, cell adhesion, and spreading on these biomaterials have been performed by using murine L929 fibroblasts. The new biomaterials showed a good cell compatibility and ability to allow ce…
Elastomeric Electrospun Polyurethane Scaffolds: The Interrelationship Between Fabrication Conditions, Fiber Topology, and Mechanical Properties
2010
Electrospinning has been gaining increasing popularity in the fabrication of engineered tissue scaffolds due to its ability to produce nano to micro scale fibrous sheets. Many investigators have attempted to apply various degrees of control to this process in order to produce fiber meshes with more predictable patterns. These attempts have largely been limited to controlling fiber alignment and have fallen into two categories: physical manipulation of the fibers by pulling them into alignment using a rapidly spinning mandrel[1–3] or manipulation of the electric field during fabrication.[4, 5]
Chemical hydrogels based on a hyaluronic acid-graft-α-elastin derivative as potential scaffolds for tissue engineering
2013
In this work hyaluronic acid (HA) functionalized with ethylenediamine (EDA) has been employed to graft α-elastin. In particular a HA-EDA derivative bearing 50 mol% of pendant amino groups has been successfully employed to produce the copolymer HA-EDA-g-α-elastin containing 32% w/w of protein. After grafting with α-elastin, remaining free amino groups reacted with ethylene glycol diglycidyl ether (EGDGE) for producing chemical hydrogels, proposed as scaffolds for tissue engineering. Swelling degree, resistance to chemical and enzymatic hydrolysis, as well as preliminary biological properties of HA-EDA-g-α-elastin/EGDGE scaffold have been evaluated and compared with a HA-EDA/EGDGE scaffold. T…
Blend scaffolds with polyaspartamide/polyester structure fabricated via TIPS and their RGDC functionalization to promote osteoblast adhesion and prol…
2019
Target of this work was to prepare a RGDC functionalized hybrid biomaterial via TIPS technique to achieve a more efficient control of osteoblast adhesion and diffusion on the three-dimensional (3D) scaffolds. Starting from a crystalline poly(l-lactic acid) (PLLA) and an amorphous alpha,beta-poly(N-2-hydroxyethyl) (2-aminoethylcarbamate)-d,l-aspartamide-graft-polylactic acid (PHEA-EDA-g-PLA) copolymer, blend scaffolds were characterized by an appropriate porosity and pore interconnection. The PHEA-EDA-PLA interpenetration with PLLA improved hydrolytic susceptibility of hybrid scaffolds. The presence of free amino groups on scaffolds allowed to tether the cyclic RGD peptide (RGDC) via Michael…
Core-shell PLA/Kef hybrid scaffolds for skin tissue engineering applications prepared by direct kefiran coating on PLA electrospun fibers optimized v…
2021
Abstract Over the recent years, there is a growing interest in electrospun hybrid scaffolds composed of synthetic and natural polymers that can support cell attachment and proliferation. In this work, the physical and biological properties of polylactic acid (PLA) electrospun mats coated with kefiran (Kef) were evaluated. Gravimetric, spectroscopic (FTIR-ATR) and morphological investigations via scanning electron microscopy confirmed the effective formation of a thin kefiran layer wrapped on the PLA fibers with an easy-tunable thickness. Air plasma pre-treatment carried out on PLA (P-PLA) affected both the morphology and the crystallinity of Kef coating as confirmed by differential scanning…