Microencapsulation of hemoglobin in chitosan-coated alginate microspheres prepared by emulsification/internal gelation
Autor(a) principal: | |
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Data de Publicação: | 2005 |
Outros Autores: | , , , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
Texto Completo: | http://hdl.handle.net/10316/7950 https://doi.org/10.1208/aapsj070488 |
Resumo: | Chitosan-coated alginate microspheres prepared by emulsification/internal gelation were chosen as carriers for a model protein, hemoglobin (Hb), owing to nontoxicity of the polymers and mild conditions of the method. The influence of process variables related to the emulsification step and microsphere recovering and formulation variables, such as alginate gelation and chitosan coating, on the size distribution and encapsulation efficiency was studied. The effect of microsphere coating as well its drying procedure on the Hb release profile was also evaluated. Chitosan coating was applied by either a continuous microencapsulation procedure or a 2-stage coating process. Microspheres with a mean diameter of less than 30 µm and an encapsulation efficiency above 90% were obtained. Calcium alginate cross-linking was optimized by using an acid/CaCO3 molar ratio of 2.5, and microsphere-recovery with acetate buffer led to higher encapsulation efficiency. Hb release in gastric fluid was minimal for air-dried microspheres. Coating effect revealed a total release of 27% for 2-stage coated wet microspheres, while other formulations showed an Hb release above 50%. Lyophilized microspheres behaved similar to wet microspheres, although a higher total protein release was obtained with 2-stage coating. At pH 6.8, uncoated microspheres dissolved in less than 1 hour; however, Hb release from air-dried microspheres was incomplete. Chitosan coating decreased the release rate of Hb, but an incomplete release was obtained. The 2-stage coated microspheres showed no burst effect, whereas the 1-stage coated microspheres permitted a higher protein release. |
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Microencapsulation of hemoglobin in chitosan-coated alginate microspheres prepared by emulsification/internal gelationAlginateChitosanInternal gelationOral protein deliveryMicrospheresChitosan-coated alginate microspheres prepared by emulsification/internal gelation were chosen as carriers for a model protein, hemoglobin (Hb), owing to nontoxicity of the polymers and mild conditions of the method. The influence of process variables related to the emulsification step and microsphere recovering and formulation variables, such as alginate gelation and chitosan coating, on the size distribution and encapsulation efficiency was studied. The effect of microsphere coating as well its drying procedure on the Hb release profile was also evaluated. Chitosan coating was applied by either a continuous microencapsulation procedure or a 2-stage coating process. Microspheres with a mean diameter of less than 30 µm and an encapsulation efficiency above 90% were obtained. Calcium alginate cross-linking was optimized by using an acid/CaCO3 molar ratio of 2.5, and microsphere-recovery with acetate buffer led to higher encapsulation efficiency. Hb release in gastric fluid was minimal for air-dried microspheres. Coating effect revealed a total release of 27% for 2-stage coated wet microspheres, while other formulations showed an Hb release above 50%. Lyophilized microspheres behaved similar to wet microspheres, although a higher total protein release was obtained with 2-stage coating. At pH 6.8, uncoated microspheres dissolved in less than 1 hour; however, Hb release from air-dried microspheres was incomplete. Chitosan coating decreased the release rate of Hb, but an incomplete release was obtained. The 2-stage coated microspheres showed no burst effect, whereas the 1-stage coated microspheres permitted a higher protein release.2005info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articlehttp://hdl.handle.net/10316/7950http://hdl.handle.net/10316/7950https://doi.org/10.1208/aapsj070488engThe AAPS Journal. 7:4 (2005) E903-E913Silva, CatarinaRibeiro, AntónioFigueiredo, MargaridaFerreira, DomingosVeiga, Franciscoinfo:eu-repo/semantics/openAccessreponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãoinstacron:RCAAP2022-05-25T04:12:20Zoai:estudogeral.uc.pt:10316/7950Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-19T20:47:26.918949Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãofalse |
dc.title.none.fl_str_mv |
Microencapsulation of hemoglobin in chitosan-coated alginate microspheres prepared by emulsification/internal gelation |
title |
Microencapsulation of hemoglobin in chitosan-coated alginate microspheres prepared by emulsification/internal gelation |
spellingShingle |
Microencapsulation of hemoglobin in chitosan-coated alginate microspheres prepared by emulsification/internal gelation Silva, Catarina Alginate Chitosan Internal gelation Oral protein delivery Microspheres |
title_short |
Microencapsulation of hemoglobin in chitosan-coated alginate microspheres prepared by emulsification/internal gelation |
title_full |
Microencapsulation of hemoglobin in chitosan-coated alginate microspheres prepared by emulsification/internal gelation |
title_fullStr |
Microencapsulation of hemoglobin in chitosan-coated alginate microspheres prepared by emulsification/internal gelation |
title_full_unstemmed |
Microencapsulation of hemoglobin in chitosan-coated alginate microspheres prepared by emulsification/internal gelation |
title_sort |
Microencapsulation of hemoglobin in chitosan-coated alginate microspheres prepared by emulsification/internal gelation |
author |
Silva, Catarina |
author_facet |
Silva, Catarina Ribeiro, António Figueiredo, Margarida Ferreira, Domingos Veiga, Francisco |
author_role |
author |
author2 |
Ribeiro, António Figueiredo, Margarida Ferreira, Domingos Veiga, Francisco |
author2_role |
author author author author |
dc.contributor.author.fl_str_mv |
Silva, Catarina Ribeiro, António Figueiredo, Margarida Ferreira, Domingos Veiga, Francisco |
dc.subject.por.fl_str_mv |
Alginate Chitosan Internal gelation Oral protein delivery Microspheres |
topic |
Alginate Chitosan Internal gelation Oral protein delivery Microspheres |
description |
Chitosan-coated alginate microspheres prepared by emulsification/internal gelation were chosen as carriers for a model protein, hemoglobin (Hb), owing to nontoxicity of the polymers and mild conditions of the method. The influence of process variables related to the emulsification step and microsphere recovering and formulation variables, such as alginate gelation and chitosan coating, on the size distribution and encapsulation efficiency was studied. The effect of microsphere coating as well its drying procedure on the Hb release profile was also evaluated. Chitosan coating was applied by either a continuous microencapsulation procedure or a 2-stage coating process. Microspheres with a mean diameter of less than 30 µm and an encapsulation efficiency above 90% were obtained. Calcium alginate cross-linking was optimized by using an acid/CaCO3 molar ratio of 2.5, and microsphere-recovery with acetate buffer led to higher encapsulation efficiency. Hb release in gastric fluid was minimal for air-dried microspheres. Coating effect revealed a total release of 27% for 2-stage coated wet microspheres, while other formulations showed an Hb release above 50%. Lyophilized microspheres behaved similar to wet microspheres, although a higher total protein release was obtained with 2-stage coating. At pH 6.8, uncoated microspheres dissolved in less than 1 hour; however, Hb release from air-dried microspheres was incomplete. Chitosan coating decreased the release rate of Hb, but an incomplete release was obtained. The 2-stage coated microspheres showed no burst effect, whereas the 1-stage coated microspheres permitted a higher protein release. |
publishDate |
2005 |
dc.date.none.fl_str_mv |
2005 |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://hdl.handle.net/10316/7950 http://hdl.handle.net/10316/7950 https://doi.org/10.1208/aapsj070488 |
url |
http://hdl.handle.net/10316/7950 https://doi.org/10.1208/aapsj070488 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
The AAPS Journal. 7:4 (2005) E903-E913 |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.source.none.fl_str_mv |
reponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação instacron:RCAAP |
instname_str |
Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
instacron_str |
RCAAP |
institution |
RCAAP |
reponame_str |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
collection |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
repository.name.fl_str_mv |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
repository.mail.fl_str_mv |
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1799133752013619200 |