Synthesis and Characterization of Six-Arm Star Poly(δ-valerolactone)-<i>b</i><i>lock</i>-Methoxy Poly(ethylene glycol) Copolymers
Bibliographic record
Abstract
Novel amphiphilic six-arm star diblock copolymers based on biocompatible and biodegradable poly(delta-valerolactone) (PVL) and methoxy poly(ethylene glycol) (MePEG) were synthesized by a two-step process. First, the hydrophobic star-shaped PVL with hydroxyl terminated functional groups was synthesized using a multifunctional alcohol, dipentaerythritol (DPE), as the initiator and fumaric acid as the catalyst. The amphiphilic six-arm star copolymer of poly(delta-valerolactone)-b-methoxy poly(ethylene glycol), (PVL-b-MePEG)(6), was then synthesized by coupling the hydroxyl terminated six-arm PVL homopolymer with alpha-methoxy-omega-chloroformate-poly(ethylene glycol) (MePEG-COCl). (1)H NMR and GPC analyses confirmed the successful synthesis of star-shaped copolymers with predicted compositions and narrow molecular weight distributions. DSC analysis revealed that the glass transition temperatures of the star PVL homopolymers with M(n) between 5000 and 49 000 are not dependent on their molecular weights, whereas the melting temperatures of both the PVL homopolymers and the amphiphilic (PVL-b-MePEG)(6) copolymers increase with an increase in the PVL molecular weight. Micelles were prepared from the (PVL-b-MePEG)(6) copolymers via the dialysis method and found to have effective mean diameters ranging from 10 to 45 nm, depending on the copolymer composition. In addition, the (PVL-b-MePEG)(6) copolymers having lower PVL content were found to form micelles with a narrow monomodal size distribution, whereas the copolymers having higher PVL content tended to form aggregates with a bimodal size distribution. The noncytotoxicity of the copolymers was also confirmed in CHO-K1 fibroblast cells using a cell viability assay, indicating that the (PVL-b-MePEG)(6) copolymers are suitable for biomedical applications such as drug delivery.
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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) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 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".