These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Preparation and characterization of pH-sensitive anionic hydrogel microparticles for oral protein-delivery applications.
    Author: Kim B, Lim SH, Ryoo W.
    Journal: J Biomater Sci Polym Ed; 2009; 20(4):427-36. PubMed ID: 19228445.
    Abstract:
    pH-sensitive P(MAA-g-EG) anionic hydrogel microparticles having an average diameter of approx. 4 microm were prepared by suspension photopolymerization. The pH-sensitive swelling and release behaviors of the P(MAA-g-EG) hydrogel microparticles were investigated as a biological on-off switch for the design of an oral protein delivery system triggered by external pH changes in the human GI tract. There was a drastic change of the equilibrium weight swelling ratio of P(MAA-g-EG) particles at a pH of around 5, which is the pK(a) of PMAA. At pH < 5, the particles were in a relatively collapsed state, while at a pH > 5 the particles swelled to a high degree. When the concentration of the cross-linker of the hydrogel increased, the swelling ratio of the P(MAA-g-EG) hydrogel microparticles decreased at a pH higher than 5 and the pK(a) of all the microparticles was in the pH range 4.0-6.0. In release experiments using Rhodamine B (Rh-B) as a model solute, the P(MAA-g-EG) hydrogel microparticles showed a pH-responsive release behavior. At low pH (pH 4.0) only a small amount of Rh-B was released while at high pH (pH 6.0) a relatively large amount of Rh-B was released from the hydrogel particles.
    [Abstract] [Full Text] [Related] [New Search]