Fabrication of porous scaffolds using microspheres prepared by double emulsion

Abstract

In recent years, drug delivery systems in tissue engineering have gained increasing research interest. Drug loaded microspheres prepared using double emulsion method were used as building blocks to fabricate porous three-dimensional scaffolds for tissue engineering applications. Microspheres with smooth, non-porous surfaces were achieved using a low, economic amount of poly(lactic-co-glycolic acid) at 1.5% w/v oil phase. These microspheres were then fused together using dichloromethane vapor at various time intervals to form scaffolds. Ideal morphological fusion patterns with high porosities were obtained. The pore sizes of the fabricated scaffold were comparable with the microsphere sizes, giving greater control over the scaffold pore sizes by simply changing the microsphere sizes using double emulsion. Bovine serum albumin release studies of the microspheres and scaffolds over 28 days revealed the flexibility of this microspheres fusion technique. The release profile of the microspheres was translated into the release profiles of the scaffolds, where all three release profiles showed initial burst release followed by slow continuous release. All findings were verified with large-sized and small-sized samples. This study highlighted the simplicity and flexibility of this process. This process can be easily modified, for example with the incorporation of growth factors in microspheres, to suit various applications in the drug delivery and tissue engineering field such as promoting greater body tissue regeneration with the seeded scaffolds.