Novel Alginate-Poly(L-histidine) Microcapsules as Drug Carriers: In Vitro Protein Release and Short Term Stability
Spherical, smooth‐surfaced and mechanically stable alginate‐poly(L‐histidine) (PLHis) microcapsules with narrow particle size distributions were prepared by incubating calcium alginate beads in aqueous solutions of PLHis. The in vitro release characteristics, drug loading and encapsulation efficienc...
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Published in | Macromolecular bioscience Vol. 5; no. 5; pp. 408 - 414 |
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Main Authors | , , , |
Format | Journal Article |
Language | English |
Published |
Weinheim
WILEY-VCH Verlag
23.05.2005
WILEY‐VCH Verlag Wiley-VCH |
Subjects | |
Online Access | Get full text |
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Summary: | Spherical, smooth‐surfaced and mechanically stable alginate‐poly(L‐histidine) (PLHis) microcapsules with narrow particle size distributions were prepared by incubating calcium alginate beads in aqueous solutions of PLHis. The in vitro release characteristics, drug loading and encapsulation efficiency of the microcapsules were investigated using bovine erythrocytes hemoglobin (Hb) as a model drug. The results showed that the concentration of Ca2+ ions had a considerable effect on the drug loading, encapsulation efficiency and in vitro release behavior of the microcapsules. When the concentration of CaCl2 in the PLHis solution was increased from 0 to 3.0% (w/v), the drug loading and encapsulation efficiency decreased significantly from 38.0 to 4.3% and from 92.9 to 8.0%, respectively, while the total cumulative release of Hb from microcapsules in phosphate buffered saline solution (PBS, pH 6.8) decreased from 96.2 to 72.8% in 24 h. No significant protein release was observed during 70 h of incubation in hydrochloric acid solution (pH 1.2). However, under neutral conditions (PBS, pH 6.8), the Hb was completely and stably released within 24–70 h. An explosion test showed that the stability of alginate‐PLHis microcapsules depended strongly on the concentration of PLHis and the calcium ions in solution.
Microscopy photo of Hb‐loaded alginate‐PLHis microcapsules. |
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Bibliography: | ArticleID:MABI200400204 istex:72940A0AA6D98FC6D2B1475032BC62F63DCCD054 ark:/67375/WNG-7W97ZM11-6 ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 1616-5187 1616-5195 |
DOI: | 10.1002/mabi.200400204 |