In this paper, we report on engineering 3-D pulmonary tissue constructs in vitro. Primary isolates of murine embryonic day 18 fetal pulmonary cells (FPC) were comprised of a mixed population of epithelial, mesenchymal, and endothelial cells as assessed by immunohistochemistry and RT-PCR of 2-D cultures. The alveolar type II (AE2) cell phenotype in 2-D and 3-D cultures was confirmed by detection...

In this work, nanocomposite membranes based on graphene and polylactide were evaluated for mechanical properties biocompatibility. Single-layer (SLG), nanosheets (GNS), poly L-lactic acid (PLLA) prepared through layer-by-layer deposition homogeneous mixing. The results revealed that PLLA/SLG nanocomposites PLLA/GNS could show enhanced addition of a tiny amount SLG significantly improved Young’s...

Poly(L-lactic acid) (PLLA) was immersed in a simulated body fluid (SBF) solution at 37.58C for distinct times. The variation of the surface mechanical properties of PLLA samples with immersion time was followed by microhardness. These measurements showed that PLLA microhardness decreased significantly ( 60%) after only 30 days of immersion. The results were explained in terms of hydrolytic degr...

BACKGROUND Two methoxyl poly(ethylene glycol)-poly(L-histidine)-poly(L-lactide) (mPEG-PH-PLLA) triblock copolymers with different poly(L-histidine) chain lengths were synthesized. The morphology and biocompatibility of these self-assembled nanoparticles was investigated. METHODS Doxorubicin, an antitumor drug, was trapped in the nanoparticles to explore their drug-release behavior. The drug-l...

Nanoindentation of cellulose diacetate-graft-poly(lactide)s (CDA-g-PLLAs) synthesized by ring opening graft copolymerization of L-lactide in bulk onto the residual hydroxyl positions on CDA were conducted to investigate the effect of the molecular composition and thermal aging on mechanical properties and creep behavior. Continuous stiffness measurement (CSM) technique was used to obtained hard...

In bone engineering, the adhesion, proliferation and differentiation of mesenchymal stromal cells rely on signaling from chemico-physical structure of the substrate, therefore prompting the design of mimetic "extracellular matrix"-like scaffolds. In this study, three-dimensional porous poly-L-lactic acid (PLLA)-based scaffolds have been mixed with different components, including single walled c...

Poly-L-lactic acid (PLLA) is accepted as a suitable material for bone pins and sutures in the medical field due to its biodegradable nature and ease of manipulation. Through this study, many of PLLA’s notable attributes were tested in order to further characterize the polymer and encourage expansion in its biomedical applications. Using X-ray diffraction, the material’s molecular structure was ...

The strength retention characteristics of oriented semicrystalline polylactides were monitored during hydrolytic degradation in vitro. The effects of the polymer type, the material's initial inherent viscosity (iv), the sample diameter and the residual monomer content on strength retention were analyzed. The analyzed polylactides had similar, but not identical, strength retention characteristic...

Scaffolds are crucial to tissue engineering/regeneration. In this work, a technique combining a unique phase-separation process with a novel sugar sphere template leaching process has been developed to produce three-dimensional scaffolds. The resulting scaffolds possess high porosities, well connected macropores, and nanofibrous pore walls. The technique advantageously controls macropore shape ...