Search results for "Poly-L-Lactic acid"
showing 10 items of 11 documents
A poly-L-lactic acid/ collagen/glycosaminoglycan matrix for tissue engineering applications
2017
Adhesion of tissue cells to biomaterials is a prerequisite of paramount importance for the effectiveness of a tissue engineering construct (cell and scaffolds). Functionalization of polymeric scaffolds with organic polymers, such as collagen or proteoglycans, is a promising approach in order to improve the cytocompatibility. As a matter of fact, organic polymers, isolated directly from the extracellular matrix, contain a multitude of surface ligand (fibronectin, laminin, vitronectin) and arginine–glycine–aspartic acid-containing peptides that promote cell adhesion. In tissue engineering, the combination of organic and synthetic polymers gives rise to scaffolds characterized simultaneously …
Double Flow Bioreactor for In Vitro Test of Drug Delivery.
2015
In this work, double-structured polymeric scaffolds were produced, and a double flow bioreactor was designed and set up in order to create a novel system to carry out advanced in vitro drug delivery tests. The scaffolds, consisting of a cylindrical porous matrix, are able to host cells, thus mimicking a three-dimensional tumor mass: moreover, a âpseudo-vascularâ structure was embedded into the matrix, with the aim of allowing a flow circulation. The structure that emulates a blood vessel is a porous tubular-shaped scaffold prepared by Diffusion Induced Phase Separation (DIPS), with an internal lumen of 2 mm and a wall thickness of 200 micrometers. The as-prepared vessel was incorporated…
A 3D‑scaffold of PLLA induces the morphological differentiation and migration of primary astrocytes and promotes the production of extracellular vesi…
2019
The present study analyzed the ability of primary rat astrocytes to colonize a porous scaffold, mimicking the reticular structure of the brain parenchyma extracellular matrix, as well as their ability to grow, survive and differentiate on the scaffold. Scaffolds were prepared using poly-L-lactic acid (PLLA) via thermally-induced phase separation. Firstly, the present study studied the effects of scaffold morphology on the growth of astrocytes, evaluating their capability to colonize. Specifically, two different morphologies were tested, which were obtained by changing the polymer concentration in the starting solution. The structures were characterized by scanning electron microscopy, and a…
PLLA scaffolds with controlled architecture as potential microenvironment for in vitro tumor model
2019
Abstract The "microenvironment" where a tumor develops plays a fundamental role in determining its progression, the onset of metastasis and, eventually, its resistance to therapies. Tumor cells can be considered more or less invasive depending both on the nature of the cells and on the site where they are located. Commonly adopted laboratory culture protocols for the investigation of tumor cells take usually place on standard two-dimensional supports. However, such cultures do not allow for reproduction of the biophysical properties of the tumor’s microenvironment, thus causing the cells to lose most of their relevant characteristics. In this work MDA-MB 231 breast cancer cells were cultiva…
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 …
3D cultures of rat astrocytes and brain capillary endothelial cells on Poly-L-lactic acid scaffolds
2016
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. In this communication we report setting of three-dimensional structures able to mimic the extracellular matrix of the nervous system: we prepared Poly-L-Lactic Acid (PLLA) porous scaffolds via thermally induced phase separation (TIPS), and investigated the parameters that influence porosity, average pore size and degree of interconnection, i.e. polymer concentration, temperature and time of process. Astrocytes and brain capillary endothelial cells (BCECs) were cultured on these three-…
USO DI TECNICHE AVANZATE PER LA OTTIMIZZAZIONE STRUTTURALE E FUNZIONALE DI SCAFFOLD COMPOSITI POLIMERO-CARICA INORGANICA PER LA RIGENERAZIONE OSSEA.
2020
Biocompatibility evaluation of PLLA scaffolds for vascular tissue engineering
2015
Poly-L-lactic acid (PLLA), a hemicrystalline material, has been extensively studied in applications of engineered tissues, because it is biodegradable, absorbable and it supports cell attachment and growth. The purpose of this study is to evaluate tissue/ material interactions, neovascularization and the biocompatibility of PLLA by optical and scanning electron microscopy in a model of animal implant. PLLA porous disks were implanted into the dorsal subcutis of BALB/C mice for 1, 2, 3, and 8 weeks. The bioptic samples of excised PLLA and the surrounding tissue were evaluated for inflammatory response and tissue ingrowth. The samples were divided in two halves: one was fixed in neutral buffe…
Poly-l-Lactic Acid (PLLA)-Based Biomaterials for Regenerative Medicine: A Review on Processing and Applications
2022
Synthetic biopolymers are effective cues to replace damaged tissue in the tissue engineering (TE) field, both for in vitro and in vivo application. Among them, poly-l-lactic acid (PLLA) has been highlighted as a biomaterial with tunable mechanical properties and biodegradability that allows for the fabrication of porous scaffolds with different micro/nanostructures via various approaches. In this review, we discuss the structure of PLLA, its main properties, and the most recent advances in overcoming its hydrophobic, synthetic nature, which limits biological signaling and protein absorption. With this aim, PLLA-based scaffolds can be exposed to surface modification or combined with other bi…
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…