The effect of fabrication methods on the mechanical and thermal properties of poly(lactide‐co‐glycolide) scaffolds

Abstract

The purpose of this research was to evaluate the effects of the fabrication method, poly(ethylene glycol) (PEG) molecular weight, and PEG concentration on the mechanical and thermal properties of blended poly (lactide-co-glycolide) (PLGA)/PEG scaffolds. The manufacturing process was the dominant factor. The tested fabrication processes were compression, heat molding, and solvent casting/vacuum drying. The scaffolds produced by compression were strong and brittle with mechanical properties [compressive modulus (E) $ 400 N/mm 2 ] comparable to those of trabecular bone. The heat-molded scaffolds were weaker and more ductile (E $ 45 N/mm 2 ) than the compressed scaffolds, so they were more applicable to nonload-bearing applications. The vacuum-dried scaffolds completely lacked compressive strength (E $ 5 N/mm 2 ) and were considered unsuitable for scaffolding applications. The miscibilities of the blends were also affected by the processing method and were evaluated on the basis of the meltingpoint depression of crystalline PEG. The miscibility of PLGA in PEG was greatest with vacuum drying (6-13%), followed by heat molding (0.4-1.5%) and then compression (0.2-0.8%). The application of heat and solvent to the blend successfully altered the miscibility of the two polymers. Overall, this study demonstrates the ability to fabricate scaffolds with distinct thermal and mechanical characteristics by the manipulation of the fabrication method.2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: [944][945][946][947][948][949] 2007

Mucoadhesive Microdiscs Engineered for Ophthalmic Drug Delivery: Effect of Particle Geometry and Formulation on Preocular Residence Time

“…However, microparticles composed of a blend of PLG and PEG exhibited a higher T g of 54 °C, which is attributed to the presence of PEG in the microparticles. This is consistent with a previous report, where a similar transition of T g was observed with a film made by solvent casting of PLG (75:25) and PEG (10 kDa) 27. The lack of PEG melting endotherm for the PLG/PEG microparticles could be explained by the high miscibility and small mass fraction of PEG in microparticles, probably smaller than the initial loading of 10 % w/w, due to partial PEG diffusion out of the particles during the solvent evaporation step of fabrication.…”

The influence of side group modification in polyphosphazenes on hydrolysis and cell adhesion of blends with PLGA

“…Poly(lactide-co-glycolide) (PLGA), poly(L-lactide) (PLA), and poly(glycolide) (PGA) have received considerable attention for many biomedical applications based on their good thermal stability [1–3], biocompatibility[4, 5], adequate mechanical properties [4, 6, 7], and cell adhesion [8]. These polyesters are also bioerodible [9].…”

Electrospun catechol-modified poly(ethyleneglycol) nanofibrous mesh for anti-fouling properties

“…In addition, the reason that the higher T m of NF was signicantly increased compared to those of 8cPEGa is attributed to the immiscibility of 8cPEGa with PLGA-SH. [28][29][30][31] The crystalline region of PEG is known to be separate from PLGA in the mixture of 8cPEG and PLGA-SH and forms multiple domains in the polymeric chains. Upon increasing the amount of PEG in the blend (10, 30, and 50%), the number of the PEG domains in the mixture is accordingly increased, which consequently increases the crystallinity as well as the T m values.…”