Hydrolysis kinetics of poly(d,l-lactide) monolayers spread on basic or acidic aqueous subphases

Adsorption of Poly(ethylene oxide)–Poly(lactide) Copolymers. Effects of Composition and Degradation

“…Analogous to the solution behavior (see above), the interfacial degradation of this polymer is very slow at neutral conditions, but accelerated at either high or low pH. Also, Ivanova et al investigated the interfacial degradation of poly(lactic acid) at the air-water interface (48,49). Analogous to the solution degradation, these authors found indications of insoluble segments also at relatively high degrees of degradation, which is compatible with the findings of the present investigation.…”

study on hydrolytic kinetics of Langmuir monolayers of biodegradable polylactide derivatives

“…[10][11][12][13][14][15] The low molecular weight oligomers and monomers generated by hydrolysis dissolve into water. This would result in a change in the occupied area if the monolayer is maintained at a constant surface pressure.…”

“…This latter result is in accordance with other reported work, 13,17 which also showed a significant hydroly- sis on basic pH's. Ivanova et al 12 reported that hydrolysis of the dl-PLA monolayer at pH=1.9 occurred, but used a very different experimental procedure than used. Under alkaline subphase of pH 10.5, the extent of area reduction appears to increase upon lowering the surface pressure.…”

“…[12][13][14][15] In this study, the hydrolytic degradation of modified polylactides has been systematically investigated at the air/water interface as a function of subphase pH, concentration of degradation medium (alkaline or enzyme), and degradation time.…”

Efficient Nuclear Delivery and Nuclear Body Localization of Antisense Oligo-Nucleotides using Degradable Polymersomes

“…For physiological conditions at 37 C, pH 7.4, 290 mOsm, for acidic intercellular condition, at pH 5.5 were measured. The hydrolysis of PEO-PCL was accelerated in acidic condition, so the releasing time was shortened in the acidic condition [16]; half time for releasing was 4.5 hrs at pH 7.4 and 3.4 hrs at pH 5.5. The vesicles were stable at 4 C for 3 days with no significant release of AON.…”