Enzyme loaded biodegradable microspheres in vitro ex vivo evaluation

Prolidase is a naturally occurring enzyme involved in the final stage of protein catabolism. Deficient enzyme activity
causes prolidase deficiency (PD), a rare autosomal recessive inherited disorder whose main manifestations are chronic,
intractable ulcerations of the skin, particularly of lower limbs. Although several attempts have been made towards the
treatment of this pathology, a cure for this disease has yet to be found. The purpose of this work is to evaluate the possibility
of enzyme replacement therapy through prolidase microencapsulation in biodegradable microspheres. The poly(D,L-lactideco-
glycolide) (PLGA) prolidase loaded microparticulate systems have been prepared utilizing the w–o–w double emulsion
solvent evaporation method. They have been characterized ‘‘in vitro’’ by morphological analysis, total protein content and an
in vitro dissolution test of active protein. ‘‘Ex vivo’’ evaluation of prolidase activity from the microspheres has been
performed on cellular extracts of cultured skin fibroblasts from healthy subjects (controls) and from patients affected by PD.
The results reported in this work on prolidase from pig kidney (available on the market) demonstrate the positive role of
microencapsulation as a process of enzymatic activity stabilization inside PLGA microspheres achieving both in vitro and ex
vivo active enzyme release. This formulation can be proposed as a parenteral depot drug delivery system.