Modified Polylactide Microfiber Scaffolds for Tissue Engineering

Abstract

Physical properties of porous membranes made of biocompatible and biodegradable polymers have been studied. The membranes are intended to be used as scaffolds for the regeneration of soft and hard tissues. Polylactides, polycaprolactone and some of their derivates are biocompatible as well as biodegradable materials, and are used for the preparation of nanofibers and nanoporous membranes. These membranes also have comparative advantages as cellular scaffolds for tissue engineering since they can be prepared to mimic the morphology of the extra cellular matrix.Chemical, physical, and biological properties of microfibers and scaffolds of polylactic acid (PLLA), as well as PLLA modified with hydroxyapatite nanoparticles and collagen (Col) are reported in this paper. The microfibers and the scaffolds were prepared by electrospinning. Morphology, diameter and porosity of the scaffold were determined by scanning electron microscopy and an image analyzer program. The microfibers are semicrystalline showing a shell of crystalline nanofibrils. The diameter of the fibers varied between 100 and 800 nm and the porous area of the membrane is between 60 and 80%. The mechanical properties of the microfibers and scaffolds were evaluated by microtensile tests and their behavior was simulated by using an original multiscale asymptotic homogenization model. Cultures of mesenchymal stem cells were used to evaluate their biological activity. Cell adhesion was observed in the modified PLLA scaffolds with grafted hydroxyapatite.

Biocompatibility Evaluation of Electrospun Scaffolds of Poly (L-Lactide) with Pure and Grafted Hydroxyapatite

“…Both of the bacterial assays shows that all PLLA/PLLA-g-HA and PLLA/HA scaffolds are excellent substrates that enable efficient bacterial cell adhesion. The results are in accordance with the good bioadhesive properties for eukaryotic cells previously observed [14]. We can resume that to promote bacterial adhesion the substrate need to be hydrophobic, and for cellular protein adhesion the substrate has to be hydrophilic.…”

“…In the scaffolds under our study no preferential position tendency of the cells onto the scaffold fibers was observed suggesting that the cell morphology is independent of the topography of the fibers. This observation is relevant because roughness may lead to the morphology and position of the cells in a scaffold [14].…”

“…Especially the material containing 4% of PLLA-grafted HA, which has the best properties, in comparison with higher concentrations of PLLA-grafted HA, and the scaffolds made of mixtures with non-grafted HA. The biological properties of the scaffolds were studied by cell adhesion of mesenchymal stem cells through immunofluorescence tests [14].…”

Efectos del tratamiento térmico y del método de colección sobre la estructura cristalina de las nanofibras electrohiladas de ácido poli (láctico)

“…Las soluciones de PLA fueron preparadas según la metodología usada por Vera et al [12] Tratamiento post electrohilado Con el fin de mejorar las propiedades estructurales y mecánicas de las fibras, estas fueron sometidas a un proceso de calentamiento a 80 ºC durante 10 horas. La temperatura de este proceso fue dada de acuerdo a la temperatura de transición vítrea del polímero (Tg = 60 ºC), con lo cual se asegura un cambio en la estructura interna del polímero.…”

“…Key words: Poly Lactic Acid, electrospinning, nanofibers, crystallinity, mechanic properties. para la regeneración dental, utilizando la técnica de electrohilado [12]. Se obtuvieron andamios de PLA mezclado e injertado con nano partículas de hidroxiapatita.…”