Search results for "PLLA"

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

2009

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…

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-…

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…

Characterization of PLLA scaffolds for biomedical applications

2017

The porosity and pore size distribution of three-dimensional scaffolds have direct implications on their biomedical applications (tissue engineering, drug delivery, and wound dressing). Accordingly, in this paper, a fast, facile, and conservative method relying on low-field nuclear magnetic resonance (LF-NMR) for the evaluation of mean pore size and pore size distribution of polymeric scaffolds is reported. The applicability of the technique is demonstrated on poly-L-lactic acid scaffolds fabricated using the thermal induced phase separation. Results obtained through LF-NMR are successfully compared to scanning electron microscope and X-ray microcomputed tomography micrographs.

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

2014

GENERATION OF PREVASCULARIZED PLLA BIODEGRADABLE SCAFFOLDS BY DIP DRAWING AND DIFFUSION INDUCED PHASE SEPARATION (DIPS).

2009

A critical obstacle in tissue engineering is to develop a massive structure of living cells upon transfer from the in vitro culture conditions into the host in vivo. A vascular network is required to supply essential nutrients, including oxygen, remove metabolic waste products and provide a biochemical communication “highway”. For these reasons to build an implantable structure in which vessel formation (angiogenesis) take place is mandatory. PLLA scaffolds usable in vascular tissue engineering were generated by dip-coating via Diffusion Induced Phase Separation (DIPS) technique. The scaffolds, with a vessel-like shape, were obtained by performing a DIPS process around a nylon fibre whose d…

Bio-affinity of MC3T3-E1 osteoblastic cells with polymeric scaffold in Poly L-Lactid Acid (PLLA) for bone substitution.

2009

Damage to an organ or tissue remains a problem despite advances in medical technology. Available treatments include organs transplantation, surgical reconstruction such as mechanical devices. However, all these methodologies have several contraindications. In recent years, tissue engineering methods is considered as means to replace diseased or damaged organs. For these kind of application, the choice of scaffolding material is crucial to the success of the technique. In the function of the application, the synthetic scaffolds should meet several criteria, including: good biocompatibility, sufficient mechanical properties, and adequate biodegradability. The aim of our study was to evaluate …

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…

Tubular composite scaffolds produced via Diffusion Induced Phase Separation (DIPS) as a shaping strategy for anterior cruciate ligaments reconstructi…

Injuries of tendons and ligaments are common, especially among the young population. Anterior cruciate ligament (ACL) injuries do not heal due to its limited vascularization and hence, surgical intervention is usually required. The ideal scaffold for ligament tissue engineering (TE) should be biocompatible and possess mechanical and functional characteristics comparable to the native ACL. The Diffusion Induced Phase Separation (DIPS) technique allows the preparation of homogenous porous tubular scaffold with micro-pores using a rather simple procedure. Composites based on biodegradable polymers and bioglass have attracted much attention in tissue reconstruction and repair because of their b…