Facile fabrication of PEG-coated PLGA microspheres via SPG membrane emulsification for the treatment of scleroderma by ECM degrading enzymes.

We developed a facile fabrication method for preparing poly(ethylene glycol)(PEG)-coated poly (lactic-co-glycolic acid) (PLGA) microspheres with homogeneous size distribution via a combination of mPEG-b-PLGA and Shirasu Porous Glass membrane emulsification. Subsequently, extracellular matrix (ECM) degrading enzymes, collagenase (COLase) or hyaluronidase (HAse) were loaded into the microspheres. The obtained microspheres exhibited a sustained release of COLase or HAse over 10 days. The degradation of ECM polymers by the released COLase and HAse was confirmed in vitro. Reversal of established dermal fibrosis via degradation of over-deposited ECM is a promising treatment for scleroderma. The therapeutic effects of COLase- and HAse-loaded PLGA microspheres on scleroderma were evaluated in vivo following their intradermal administration to a bleomycin-induced mice model of scleroderma. COLase- and HAse-loaded PLGA microspheres decreased scleroderma dermal thickness without altering the mechanical properties of skin, whereas the administration of free COLase and HAse solution induced overdecomposition of skin ECM and α-SMA expression. The facile one-pot synthesis of PEG-coated PLGA microspheres with high colloidal stability and narrow size distribution could be employed as a drug carrier for various diseases in future.