Loading...
Please wait, while we are loading the content...
The microclimate pH in poly(D,L-lactide-co-hydroxymethyl glycolide) microspheres during biodegradation
| Content Provider | PubMed Central |
|---|---|
| Author | Liu, Yajun Ghassemi, Amir H. Hennink, Wim E. Schwendeman, Steven P. |
| Copyright Year | 2012 |
| Abstract | The microclimate pH (µpH) in biodegradable polymers, such as poly(D,L-lactic-coglycolic acid) (PLGA) 50/50, commonly falls to deleterious acidic levels during biodegradation, resulting in instability of encapsulated acid-labile molecules. The µpH distribution in microspheres of a more hydrophilic polyester, poly(D,L-lactide-co-hydroxymethyl glycolide) (PLHMGA), was measured and compared to that in PLGA 50/50 of similar molecular weight and degradation time scales. pH mapping in the polymers was performed after incubation under physiological conditions by using a previously validated ratiometric confocal laser scanning microscopic (CLSM) method. Confocal µpH maps revealed that PLHMGA microspheres, regardless of copolymer composition, developed a far less acidic µpH during 4 weeks of incubation compared with microspheres from PLGA. A pH-independent fluorescent probe marker of polymer matrix diffusion of µpH-controlling water-soluble acid degradation products, bodipy, was observed by CLSM to diffuse ~3–7 fold more rapidly in PLHMGA compared to PLGA microspheres, consistent with much more rapid release of acids observed from the hydrophilic polymer during bioerosion. Hence, PLHMGA microspheres are less susceptible to acidification during degradation as compared to similar PLGA formulations, and therefore, PLHMGA may be more suitable to deliver acid labile molecules such as proteins. |
| Related Links | http://dx.doi.org/10.1016/j.biomaterials.2012.06.013 |
| File Format | |
| ISSN | 01429612 |
| e-ISSN | 18785905 |
| Journal | Biomaterials |
| Issue Number | 30 |
| Volume Number | 33 |
| Language | English |
| Publisher Date | 2012-10-01 |
| Access Restriction | Open |
| Subject Keyword | Biophysics Mechanics of Materials Bioengineering Biomaterials Ceramics and Composites Research in Higher Education |
| Content Type | Text |
| Resource Type | Article |
| Subject | Ceramics and Composites Nanoscience and Nanotechnology Mechanics of Materials Biomaterials Biophysics Bioengineering |
