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Solvent mediated microstructures and release behavior of insulin from pH-sensitive nanoparticles
Zhi Min Wu1, Xin Dong Guo, Li Juan Zhang
1School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou 510640, PR China.
Colloids and Surfaces. B, Biointerfaces
|February 24, 2012
Summary
Solvent choice critically impacts nanoparticle microstructure and insulin release. Mesoporous nanoparticles prepared with DMSO show rapid, pH-insensitive release, unlike those from acetone/water.
Area of Science:
- Materials Science
- Nanotechnology
- Pharmaceutical Sciences
Background:
- Poly (lactic-co-glycolic acid) (PLGA) and hydroxypropyl methylcellulose phthalate (HP55) are key polymers for drug delivery systems.
- Controlling nanoparticle microstructure is crucial for modulating drug release profiles.
Purpose of the Study:
- To investigate the effect of different solvents (DMSO vs. acetone/water) on the microstructure of PLGA/HP55 nanoparticles.
- To analyze how these microstructural changes influence the in vitro release behavior of loaded insulin.
Main Methods:
- Emulsion solvent diffusion method using DMSO or acetone/water.
- Characterization of nanoparticle microstructure using solubility parameters theory, DSC, FTIR, and nitrogen adsorption.
- In vitro drug release studies under varying pH conditions.
Main Results:
- Nanoparticles prepared with both solvents exhibited phase-separated PLGA domains.
- Mesopores were observed in DMSO-prepared nanoparticles, but were absent in acetone/water-prepared ones.
- DMSO-prepared nanoparticles showed accelerated, pH-insensitive insulin release due to mesopores, while acetone/water-prepared nanoparticles displayed pH-dependent release.
Conclusions:
- Solvent selection significantly alters nanoparticle microstructure, specifically mesopore formation.
- Nanoparticle microstructure, influenced by solvents, is a critical determinant of insulin release kinetics and pH-sensitivity.
- The presence of mesopores can override the inherent pH-sensitivity of HP55 in drug release.
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