Control of shape and size of poly (lactic acid) microspheres based on surfactant and polymer concentration

Biodegradable, poly (lactic acid) (PLA) microspheres have been synthesized via solvent evaporation method using ultrasonic homogenizer as emulsifier. The effect of added surfactant, PVA [poly (vinyl alcohol)], and PLA concentration on the shape and size of the resultant PLA microspheres has been studied. The prime objective of this work was to identify an optimal PVA/PLA concentration to prepare PLA microsphere with a size distribution of 1-2 micrometers as in many literature it has been reported as ideal range of size for non-endocytosis-mediated cellular drug delivery. In this pursuit it was found that an optimal concentration of 2.5% w/v of PVA into water and 2.5% w/v PLA into DCM [Dichloromethane] is suitable to create PLA microspheres with a size distribution of 1-2 micrometers. The PLA microspheres were characterized by FESEM to assess their shape and size. FT-IR analysis (Supplementary data) was used to assess the functional groups present in the PLA microspheres, whilst zeta-potential measurements (Supplementary data) provided insight into the likely dispersion properties of the microspheres in aqueous media.