Stability of Acetals/Ketals Under Controlled Radical and Ring Opening Polymerization
Bibliographic record
Abstract
Well-defined acid-degradable amphiphilic block copolymers (ABPs) and their nanoassemblies labeled with acid-labile groups have been developed for smart drug delivery, exhibiting controlled/enhanced release of therapeutics in tumoral tissues and endo/lysosomes. In general, controlled polymerization techniques, particularly atom transfer radical polymerization (ATRP) and ring opening polymerization (ROP) have been utilized to synthesize poly(ethylene glycol)-based ABPs labeled with acetals and ketals. Despite comprehensive studies on their acid-catalyzed hydrolysis rate with substituents attached to oxygen atoms, the stability of the groups under ATRP and tin-catalyzed ROP conditions have been rarely studied. Herein, we report our investigation with benzaldehyde acetal (BzAc) as a typical acetal and cyclohexyl ketal (CyHK) as a typical ketal to understand the relationship of sensitivity to acid and stability to controlled polymerizations for acetals and ketals. Our results, along with model studies, show that BzAc is stable under ATRP, but partially stable under tin-catalyzed ROP conditions, while CyHK turns to be unstable under both ATRP and ROP conditions. Our work could provide important design principles for the synthesis of well-defined acid-degradable ABPs with respect to acid-catalyzed hydrolysis rates, thus eventually, the release rate of encapsulated drug molecules from their nanoassemblies in an acidic environment.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".