Hollow microshell through layer-by-layer self-assembly of chitosan/alginate on «E.coli»
Bibliographic record
Abstract
Hollow microspheres prepared via layer-by-layer (LbL) self-assembled polymers have become a growing interest for developing biocompatible delivery systems for drugs, imaging probes and other macromolecules.The development of these capsules benefits from ease of fabrication, versatility of materials being used and its ability to be tuned to the application by incorporating pH-sensitivity as well as targeting molecules.The LbL method has been used to construct capsules for delivering anti-cancer drugs, insulin and other therapeutics.Furthermore, previous work done in the lab has exploited this technique to obtain polyelectrolyte-coated E. coli for use as a bio-recognition element and discovered that a hollow polyelectrolyte capsule can be formed by spontaneous cell lysis.Following that observation, the current project aims to develop a protocol for making hollow capsules by LbL assembly of natural polyelectrolytes onto E. coli, subsequently lysing the cells and evaluating their efficacy using quantum dots as cargo.The study found that four bilayers of chitosan/alginate can be produced on the surface of the E. coli cells with good stability/minimal aggregation as verified by zeta-potential measurements.TEM and confocal microscopy were also used to characterize the capsule formation, thickness and morphology.Cell lysis was performed using 1% Triton-X buffer with EDTA and lysozyme, which resulted in empty vesicles with a wall thickness of ~50 nm and similar dimensions as the cell template.The design of a tunable and biocompatible delivery system is crucial in controlling the biodistribution of imaging probes to enhance efficacy in the targeted site as well as lower toxicity.ii ABSTRACT (FRENCH) Les microsphres creuses formes par auto-assemblage couche par couche (LBL) de polymre prsentent un intrt grandissant pour le dveloppement de systme biocompatibles de dlivrance de mdicaments, de sonde d'imagerie ainsi que d'autres types de macromolcules.Le dveloppement de ces capsules bnficie de procds de fabrication simples, d'une large varit de matriaux disponibles, ainsi que d'une bonne adaptabilit leurs applications par l'incorporation une sensibilit au pH et des molcules pour le ciblage.La mthode LBL a t employe pour construire des capsules pour la dlivrance de mdicaments anticancreux, d'insuline et d'autres thrapies.De plus, les travaux antrieurs du laboratoire ont utilis cette technique pour obtenir une bactrie E Coli revtue de polylectrolyte utilise comme lment de bioreconnaissance et ont abouti l'obtention d'une capsule creuse de polylectrolyte par lyse cellulaire spontane.Suite de ces observations, le projet actuel vise dvelopper un protocole pour la fabrication de capsules creuses par assemblage LBL de polylectrolytes naturels sur E coli et lyse cellulaire ainsi que l'valuation de leurs capacits par encapsulation de points quantiques.L'tude dmontre que 4 bicouches de chitosan / alginate peuvent tre assembls la surface de E. Coli et prsentant une bonne stabilit comme le confirme les mesures de potentiel zeta.Les microscopies TEM et confocales ont aussi t employes pour caractriser la formation des capsules, leur paisseur et leur morphologie.La lyse cellulaire a t effectue en employant un tampon 1% Triton-X contenant de l'EDTA et du lisozyme, rsultant en la formation de vsicules vides de 50 nm d'paisseur et des dimensions similaires la cellule modle.La conception d'un systme de dlivrance sur mesure et biocompatible est crucial dans le contrle de la biodistribution de sondes d'imagerie pour amliorer l'efficacit de ciblage et diminuer la toxicit.iii ACKNOWLEDGEMENT I would like to thank my supervisor Prof. Maryam Tabrizian for her support, advice and guidance throughout this project.Working with her has been an invaluable
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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 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.002 |
| Meta-epidemiology (broad) | 0.002 | 0.001 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.002 | 0.000 |
| Research integrity | 0.001 | 0.002 |
| Insufficient payload (model declined to judge) | 0.000 | 0.002 |
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; both teacher heads agree on what is shown here.
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".