The relationship between poly(lactide-co-glycolide) monomer ratio, molecular weight and hollow fibre membrane scaffold morphology

The morphological characteristics of hollow fibre membrane scaffolds are fundamental to their use for cell culture in regenerative medicine applications. This paper evaluates the morphologies of hollow fibre membrane scaffolds fabricated from six commercial poly(lactide-co-glycolide) (PLGA) polymers with lactide: glycolide (PLA: PGA) molar ratios of 45:55, 50:50, 65:35, 75:25, 85:15 and 100:0. For polymers 65:35 to 100:0 (weight-averaged molecular weight, Mw = 109-124 kDa), viscosity and effective porosity were inversely proportional to PLA content; surface roughness was proportional to PLA content and no conclusive trend was seen with outer skin thickness or mean pore size. 50:50 (Mw = 74 kDa) did not fit these trends while 45:55 (Mw = 12 kDa) was too inviscid to form a membrane. Effective porosity was also seen to be proportional to the polydispersity index (PDI). Further studies are required to investigate how the polymer properties at the molecular scale, i.e. transesterification and tacticity affect the membrane characteristics. The Mw, PLA: PGA ratio and PDI are key factors which can be selected to obtain the desired PLGA membrane morphology.