Reversible protein precipitation to ensure stability during encapsulation within PLGA microspheres.
Proteins were precipitated to ensure their stability upon subsequent encapsulation within PLGA microspheres. Spherical, nanosized protein particles were formed by the addition of a salt (sodium chloride) and a water-miscible organic solvent (glycofurol) to protein solutions. Various process parameters were modified to optimize the precipitation efficiency of four model proteins: lysozyme, alpha-chymotrypsin, peroxidase and beta-galactosidase. As monitored by enzymatic activity measurement of the rehydrated particles, conditions to obtain more than 95% of reversible precipitates were defined for each protein. The study of the structure of the rehydrated particles by absorbance spectroscopy, fluorescence spectroscopy and circular dichroism showed an absence of structural-perturbation after precipitation. Protein particles were then microencapsulated within PLGA microspheres using s/o/w technique. The average encapsulation yield was around 80% and no loss of protein activity occurred after the encapsulation step. Additionally, a lysozyme in vitro release study showed that all of the released lysozyme was biologically active. This method of protein precipitation is appropriate for the encapsulation in PLGA microspheres of various proteins without inactivation.
Giteau
Alexandra
A
INSERM U646, Angers, France.
Venier-Julienne
Marie-Claire
MC
Marchal
Stéphane
S
Courthaudon
Jean-Luc
JL
Sergent
Michèle
M
Montero-Menei
Claudia
C
Verdier
Jean-Michel
JM
Benoit
Jean-Pierre
JP
D000818:Animals; D011232:Chemical Precipitation; D002626:Chemistry, Pharmaceutical; D002918:Chymotrypsin / Q000737:chemistry; D004337:Drug Carriers; D004339:Drug Compounding; D004795:Enzyme Stability; D004798:Enzymes / Q000737:chemistry* / Q000378:metabolism; D007700:Kinetics; D019344:Lactic Acid / Q000737:chemistry*; D008863:Microspheres; D009113:Muramidase / Q000737:chemistry; D009821:Oils / Q000737:chemistry; D009195:Peroxidase / Q000737:chemistry; D011092:Polyethylene Glycols / Q000737:chemistry; D011100:Polyglycolic Acid / Q000737:chemistry*; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011487:Protein Conformation; D012965:Sodium Chloride / Q000737:chemistry; D012995:Solubility; D012997:Solvents / Q000737:chemistry; D013678:Technology, Pharmaceutical / Q000379:methods*; D014867:Water / Q000737:chemistry; D001616:beta-Galactosidase / Q000737:chemistry
D004337:Drug Carriers; D004798:Enzymes; D009821:Oils; D012997:Solvents; D014867:Water; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D011092:Polyethylene Glycols; D012965:Sodium Chloride; D009195:Peroxidase; D009113:Muramidase; D001616:beta-Galactosidase; D002918:Chymotrypsin; C117608:alpha-chymotrypsin; C018557:glycofurol