title: Stabilization and encapsulation of recombinant human erythropoietin into PLGA microspheres using human serum albumin as a stabilizer.
abstract: The aim of this study was to prepare recombinant human erythropoietin (rhEPO) loaded poly(lactic-co-glycolic acid) (PLGA) microspheres using human serum albumin (HSA) as a stabilizer. Prior to encapsulation, the rhEPO-HSA mixture microparticles were fabricated using a modified freezing-induced phase separation method. The microparticles were subsequently encapsulated into PLGA microspheres. Process optimization revealed that the polymer concentration in the organic phase and the sodium chloride (NaCl) concentration in the outer water phase of the s/o/w emulsion played critical roles in determining the properties of the resultant microspheres. An in vitro release test showed that rhEPO was released from PLGA microspheres in a sustained manner up to 30 days. A single injection of rhEPO-loaded PLGA microspheres in Sprague-Dawley rats resulted in elevated hemoglobin and red blood cell concentrations for about 33 days. The stability of the rhEPO within the PLGA microspheres was systematically investigated by size-exclusion high-performance liquid chromatography (SEC-HPLC), SDS-PAGE, western blot and in vivo biological activity assay. The stability of rhEPO released from rhEPO-loaded microspheres was also examined by western blot. The results suggested that the integrity of rhEPO was successfully protected during the encapsulation process and the release period from polymeric matrices.
authors.affiliation: Hebei Normal University, Hebei Province, People's Republic of China. he jintian@yahoo.com
authors.forename: Jintian
authors.initials: J
authors.lastname: He
authors.forename: Meiyan
authors.initials: M
authors.lastname: Feng
authors.forename: Xianglian
authors.initials: X
authors.lastname: Zhou
authors.forename: Shufen
authors.initials: S
authors.lastname: Ma
authors.forename: Yang
authors.initials: Y
authors.lastname: Jiang
authors.forename: Ying
authors.initials: Y
authors.lastname: Wang
authors.forename: Hongxia
authors.initials: H
authors.lastname: Zhang
mesh_terms: D000818:Animals; D004339:Drug Compounding / Q000379:methods*; D004355:Drug Stability; D004655:Emulsions / Q000008:administration & dosage / Q000138:chemical synthesis / Q000737:chemistry; D004906:Erythrocyte Count / Q000706:statistics & numerical data; D004921:Erythropoietin / Q000737:chemistry* / Q000494:pharmacology; D005079:Excipients / Q000737:chemistry; D006454:Hemoglobins / Q000187:drug effects; D006801:Humans; D019344:Lactic Acid / Q000737:chemistry*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008863:Microspheres; D010316:Particle Size; D011100:Polyglycolic Acid / Q000737:chemistry*; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D051381:Rats; D017207:Rats, Sprague-Dawley; D012709:Serum Albumin / Q000737:chemistry*
chemical_list: C554270:EPO protein, human; D004655:Emulsions; D005079:Excipients; D006454:Hemoglobins; D012709:Serum Albumin; D004921:Erythropoietin; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid