Novel Self-Associating Poly(ethylene oxide)-<i>b</i><i>lock</i>-poly(ε-caprolactone) Block Copolymers with Functional Side Groups on the Polyester Block for Drug Delivery
Bibliographic record
Abstract
The aim of this study was to develop micelle-forming poly(ethylene oxide)- block -poly(ε-caprolactone) (PEO- b -PCL)-based block copolymers bearing functional side groups on the PCL block. Substituted monomer, i.e, α-benzyl carboxylate-ε-caprolactone, was synthesized by anionic activation of ε-caprolactone and further treatment with benzyl chloroformate. Successful substitution of benzyl carboxylate on ε-caprolactone monomer was evidenced by 1 H NMR and mass spectroscopy. Ring-opening polymerization of α-benzyl carboxylate-ε-caprolactone with methoxy PEO (5000 g mol -1 ) as initiator and stannous octoate as catalyst was used to prepare PEO- b -poly(α-benzyl carboxylate ε-caprolactone) (PEO- b -PBCL). Further catalytic debenzylation of PEO- b -PBCL produced PEO- b -poly(α-carboxyl-ε-caprolactone) (PEO- b -PCCL). Ring-opening polymerization of a ε-caprolactone/α-benzyl carboxylate-ε-caprolactone mixture and further reduction of the product were also used to prepare block copolymers with various degrees of benzyl carboxylate or carboxyl group substitution. The calculated molecular weights determined by 1 H NMR and gel permeation chromatography (GPC) for block copolymers were in good agreement with the theoretical values. The polydispersity of PEO- b -PBCL and PEO- b -PCCL block copolymers was 1.74 and 1.52, respectively. PEO- b -PBCL and PEO- b -PCCL block copolymers assembled to spherical micelles having average diameters of 62 and 20 nm based on dynamic light scattering (DLS) measurement, respectively. PEO- b -PBCL formed micelles at extremely low concentrations (cmc of 9.8 × 10 -2 μM). The presence of carboxylic group on the PCCL block raised the cmc of PEO- b -PCCL to 1220 × 10 -2 μM. For block copolymers with PCL- co -PCCL core structures, a decrease in cmc as well as an increase in size was observed as the level of PCL to PCCL was raised. Novel PEO- b -poly(ester) block copolymers with aromatic and reactive side groups on the polyester block have tremendous potential in the design of optimized carriers for the delivery of various therapeutic agents, as they can assemble to biodegradable nanoscopic micelles with chemically tailorable core structures.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| 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) | 0.001 | 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 source (direct Gemma or distilled Codex), 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".