Spelling suggestions: "subject:"micelles."" "subject:"bicelles.""
361 |
Penetrační vlastnosti polymerních micel na bázi hydrofobizované kyseliny hyaluronové. / The penetration features of the hydrofobized hyaluronic acid – based polymeric micelles.Mischingerová, Monika January 2014 (has links)
The aim of this thesis was to investigate the penetration features of the hydrofobized hyaluronic acid – based polymeric micelles using Nile red as carried tracer. Furthermore, to implement basic characterization of polymeric micelles for potential cosmetic applications using Coenzyme Q10 (CoQ10) as carried substance. It was found that the size of the polymeric micelles with carried CoQ10 did not exceed 100 nm. Applied delivery systems based on hydrophobic hyaluronic acid were suitable for potential topical application. Delivery systems with Nile Red as carried tracer demonstrated excellent penetration features. We assume that delivery systems with CoQ10 will exhibit similar penetration features. An issue has appeared whether the carrier breaks or proceeds along with NR to the skin. Moreover, another experiments have been designed which could also verify the penetration features of these systems.
|
362 |
Block copolymer micellization, and DNA polymerase-assisted structural transformation of DNA origami nanostructuresAgarwal, Nayan Pawan 14 August 2019 (has links)
DNA Nanotechnology allows the synthesis of nanometer sized objects that can be site specifically functionalized with a large variety of materials. However, many DNA structures need a higher ionic strength than that in common cell culture buffers or in bodily fluids to maintain their integrity and can be degraded quickly by nucleases. The aim of this dissertation was to overcome this deficiency with the help of cationic PEG-poly-lysine block copolymers that can electrostatically cover the DNA nanostructures to form “DNA origami polyplex micelles” (DOPMs). This straightforward, cost-effective and robust route to protect DNA-based structures could therefore enable applications in biology and nanomedicine, where un-protected DNA origami would be degraded.
Moreover, owing to high polarity, the DNA-based structures are restricted to the aque-ous solution based buffers only. Any attempt to change the favorable conditions, leads to the distortion of the structures. In this work it was demonstrated that, by using the polyplex micellization strategy, the organic solubility of DNA origami structures can be improved. The strategy was also extended to functional ligands that are otherwise not soluble in organic solvents. With this strategy, it is now also possible to perform organic solution reactions on the DNA-based structures, opening up the possibility to use hydro-phobic organic reagents to synthesize novel materials. The polyplex micellization strategy therefore presents a cheap, robust, modular, reversible and versatile method to not only solubilize DNA structures in organic solvents but also improve their stability in biological environments.
A third project was based on the possibility to synthesize complementary sequences to single-stranded gap regions in the DNA origami scaffold cost-effectively by a DNA polymerase rather than by a DNA synthesizer. For this purpose, four different wireframe DNA origami structures were designed to have single-stranded gap regions. The introduction of flexible gap regions resulted in fully collapsed or partially bent structures due to entropic spring effects. These structures were also used to demonstrate structural transformations with the help of DNA polymerases, expanding the collapsed bent structures to straightened tubes. This approach presents a powerful tool to build DNA wireframe structures more material-efficiently, and to quickly prototype and test new wireframe designs that can be expanded, rigidified or mechanically switched.:Abstract v
Publications vii
Acknowledgements ix
Contents xiii
Chapter 1 Introduction 1
1.1 Nanotechnology 1
1.1.1 History of nanotechnology 1
1.1.2 Phenomena that occur at nanoscale 4
1.1.3 Nature’s perspective of nanotechnology 4
1.1.4 Manufacturing nanomaterials 6
1.2 Deoxyribonucleic acid (DNA) 8
1.2.1 DNA, the genetic material, “The secret of life” 8
1.2.2 Structure of DNA 9
1.2.3 DNA synthesis 15
1.2.4 Stability of DNA 18
1.3 DNA nanotechnology 20
1.3.1 Historical development 20
1.3.2 DNA tile motifs 21
1.3.3 Directed nucleation assembly and algorithmic assembly 23
1.3.4 Scaffolded DNA origami and single-stranded DNA tiles 25
1.3.5 Expanding the design space offered by DNA 27
1.3.6 Assembling heterogeneous materials with DNA 30
1.3.7 Functional devices built using DNA nanostructures 35
Chapter 2 Motivation and objectives 40
Chapter 3 Block copolymer micellization as a protection strategy for DNA origami 42
3.1 Introduction 42
3.1.1 Cellular delivery of DNA nanostructures 42
3.1.2 The need for stability of DNA nanostructures 43
3.1.3 Non-viral gene therapy 44
3.2 Results and discussions 46
3.2.1 Strategy to form DNA origami polyplex micelles (DOPMs) 46
3.2.2 Optimizations 46
3.2.3 Decomplexation 53
3.2.4 Stability tests 55
3.2.5 Short PEG-PLys block copolymer 58
3.2.6 Compatibility with bulky ligands 59
3.2.7 Accessibility of handles on DOPMs 63
3.3 Conclusion 64
3.4 Outlook and state of the art 65
3.5 Methods 67
3.5.1 DNA origami folding 67
3.5.2 Preparation of ssDNA functionalized AuNPs 68
3.5.3 Agarose gel electrophoresis 69
3.5.4 Block copolymer preparation 70
3.5.5 DNA origami polyplex micelle preparation 70
3.5.6 Decomplexation of DOPM using dextran sulfate 73
3.5.7 Stability tests 74
3.5.8 tSEM characterization 75
3.5.9 AFM imaging 76
Chapter 4 Improving organic solubility and stability of DNA origami using polyplex micellization 77
4.1 Introduction 77
4.2 Results and discussions 79
4.2.1 Strategy for organic solubility of DNA origami 79
4.2.2 Proof of concept using AuNPs functionalized with ssDNA 80
4.2.3 Extending the strategy to DNA origami 82
4.2.4 Optimizations 86
4.2.5 Compatibility with functional ligands 88
4.2.6 Functionalization of DNA origami in organic solvent 94
4.3 Conclusion and outlook 95
4.4 Methods 97
4.4.1 Conjugation of functional ligands to DNA origami 97
4.4.2 Organic solubility 98
4.4.3 Reactions in organic solution on DOPMs 99
4.4.4 Fluorescence imaging using gel scanner 100
Chapter 5 Structural transformation of wireframe DNA origami via DNA polymerase assisted gap-filling 101
5.1 Introduction 101
5.2 Results and discussion 102
5.2.1 Design of the structures 102
5.2.2 Folding of gap-structures 105
5.2.3 Single-stranded DNA binding proteins 107
5.2.4 Gap filling with different polymerases 109
5.2.5 Gap filling with Phusion high-fidelity DNA polymerase 111
5.2.6 Optimization of the extension reaction using T4 DNA polymerase 115
5.2.7 Secondary structures 121
5.2.8 Folding kinetics of gap origami 124
5.2.9 Bending of tubes 125
5.3 Conclusion 126
5.4 Outlook 127
5.5 Methods 128
5.5.1 DNA origami folding 128
5.5.2 Gap filling of the wireframe DNA origami structures 128
5.5.3 Agarose gel electrophoresis 130
5.5.4 PAGE gel analysis 130
5.5.5 tSEM characterization 131
5.5.6 AFM imaging 131
5.5.7 AGE based folding-yield estimation 132
5.5.8 Gibbs free energy simulation using mfold 132
5.5.9 Staple list for folding the DNA origami triangulated structures 132
Appendix 134
A.1 Additional figures from chapter 3 134
A.2 Additional figures from chapter 4 137
A.3 Additional figures from chapter 5 149
Bibliography 155
Erklärung 171
|
363 |
Termodinamička stabilnost odabranih micelarnih sistema žučnih soli značajnih za nove farmaceutske formulacije / Thermodynamic stability of selected bile salt micellar systems relevant for new pharmaceutical formulationsPopović Kosta 27 April 2017 (has links)
<p>Da bi se dobio sistem surfaktanata željenih osobina moguće je hemijski modifikovati već postojeće molekule površinski aktivnih supstanci, a druga mogućnost je konstrukcija binarnih smeša surfaktanata. U farmaceutskoj i prehrambenoj industriji uveliko se primenjuju binarne smeše površinski aktivnih molekula. Ukoliko je binarna mešovita micela termodinamički stabilnija od hipotetičke idealne binarne mešovite micele, onda je kritična micelarna koncentracija binarne smeše surfaktanata niža čak i od hidrofobnije gradivne jedinice mešovite micele, što znači da je za isti efekat površinske aktivnosti potrebna manja količina binarne smeše nego čistog surfaktanta. Različite gradivne jedinice binarne micele u micelarnoj pseudofazi mogu formirati specifične regije koje mogu vezivati lekove određenih strukturnih karakteristika. Pogodno je da jedna gradivna jedinica bude krute konformacije, npr. soli žučnih kiselina, dok je druga gradivna jedinica konformaciono pokretljiva (ugljovodonični nizovi iznad C10). Na taj način se povećava zapremina hidrofobne micelarne faze u odnosu na zapreminu hidrofobne micelarne faze monokomponentne micelle konformaciono krutog surfaktanta, što povećava solubilizacioni kapacitet mešovite micele u odnosu na monokomponentnu micelu krutog surfaktanta. Povećanjem dužine ugljovodoničnog niza konformaciono pokretnog surfaktanta povećava se stepen unutrašnje pokretljivosti u hidrofobnom domenu mešovite micele, što takođe povećava verovatnoću prihvatanja molekula gosta. Micelarni sistemi, kako monokomponentnih micela tako i binarnih mešovitih micela dodatno se mogu termodinamički stabilizovati povećanjem jonske jačine rastvora. Za hidrataciju katjona troše se molekuli vode iz sistema, što povećava efekat desolvatizacije hidrofobne površine surfaktanata, pa se zbog toga pospešuje samoasocijacija.</p> / <p>To obtain the surfactant system with the desired properties it is possible to chemically modify existing molecules of surface active agents. The other possibility is the construction of binary mixtures of surfactants. Binary mixtures of surface active molecules are widely used In the pharmaceutical and food industry. If the binary mixture micelle is more thermodynamically stable than the hypothetical ideal binary mixed micelle, then the critical micellar concentration (CMC) of the binary mixture of surfactants is even lower than the CMC of the more hydrophobic building block of the binary mixture. That means that for the same effect of surface activity less the amount of the binary mixture than the pure surfactants is required. The different building blocks of binary micelles in micelar pseudophase can form specific regions that can bind drugs of certain structural characteristics. It is suitable that one building block is of a rigid conformation, i.e. bile acid salts, while the second building block is of a flexible conformation (above C10 hydrocarbon arrays). In this way the volume of the hydrophobic micellar phase is increased in relation to the volume of the hydrophobic micellar phase of the monocomponent micelles of conformationally rigid surfactant, which increases the capacity of solubilisation of the mixed micelles, compared to the mono-component surfactant micelle of the rigid conformation. By increasing the length of the hydrocarbon array of the the conformational flexible surfactant, the degree of internal mobility in the hydrophobic domain of mixed micelles is also increased, which also increases the likelihood of acceptance of guest molecules. Micellar systems, of both monocomponent micelles and mixed micelles can be additionally thermodynamically stabilized by increasing the ionic strength of the solution. The hydration of cations uses the molecules of water from the system, which increases the effect of desolvatisation of the hydrophobic surface of the surfactants, and therefore promotes self-association.</p>
|
364 |
Zhášení fluorescence ve studiu agregačního chování koloidů / Fluorescence quenching in study of aggregation behavior of colloidsSrholcová, Barbora January 2010 (has links)
This work focuses on examination of hyaluronan-sulfactant aggregates in term of determination of aggregate number. The value of critical micellar concentration (CMC) cetyltrimethylammonium bromide (CTAB) in three different solvents (water, phosphate buffer and physiological solution). Next the effect of the native hyaluronan supplement on the value of CMC was examined. It wasfound out that the solvent has the biggest effect on the value of CMC whilst the hyaluronan supplement affects CMC only a little. The aggregate number (Nagg) CTAB and the effect of the native hyaluronan supplement were determined out by means of fluorescence quenching. Pyrene was used as a fluorescence probe. Iodine and cetylpyridinium chloride (CPC) were used as quenchers. Sulfactant was dissolved in three different solvents (water, phosphate buffer and physiological solution). Not only the hyaluronan supplement but also the used solvent has the strong effect on the value of the aggregate number. When using 10mM CTAB dissolved in physiological solution the value of Nagg was 119 ± 4 while the value was half in buffer. Then we found out that in most cases the hyaluronan supplement reduces the value of the aggregate number.
|
365 |
Hybrid Arborescent Polypept(o)ides for Biomedical ApplicationsMahi, Basma 11 1900 (has links)
This work reports a novel biocompatible and biodegradable arborescent amphiphilic polypept(o)ides-based polymer poly(γ-benzyl L-glutamate)-co-poly(γ-tert-butyl L-glutamate)-g-polysarcosine (P(BG-co-Glu(OtBu))-g-PSar) as a smart dual-responsive targeting drug vehicle. The synthesis pathway in this work highlighted the grafting reaction improvement of the polypeptides core and using polysarcosine (PSar) corona as a coating agent. The responsiveness of the polymer is caused by the pH sensitivity of the polypeptides and the reducible linker introduced between the core and corona. While adding the tripeptides arginine, glycine, and aspartate (RGD) as a ligand on the unimolecular micelles’ surface increases the targeting ability of the polymer.
During the building of the arborescent, the coupling sites were controlled by using γ-tert-butyl L-glutamate (Glu(OtBu)-NCA) as a second monomer besides γ-benzyl L-glutamate (BG-NCA) since the deprotection conditions are different for Bz and tBu groups. Knowing the coupling sites provides accuracy in calculating the molecular weight (MW) of graft polymers since it facilitates the determination of the grafting yield (Gy).
The arborescent unimolecular micelles were formulated by coating the hydrophobic core with PSar hydrophilic corona. The distribution of the coupling sites on the substrates in the last generation yielded end-grafted and randomly-grafted unimolecular micelles. A comparison between those micelles by DLS, TEM, and AFM revealed that the end-grafted micelles showed more uniformity in terms of morphology and size distribution. Also, the surface modification achieved via RGD addition increased the shape uniformity and contributed to avoiding the particles’ aggregation. The sizes and shapes of end-grafted unimolecular micelles match the drug delivery systems (DDSs) requirements.
Doxorubicin (DOX) was encapsulated physically into the unimolecular micelles to study the drug loading capacity (DLC) and drug loading efficiency (DLE). The maximum DLC and DLE were 14% and 28% w/w, respectively. The drug release profiles were investigated in healthy- and cancer-mimicking media. The results showed that in cancer-mimicking microenvironment (low pH and high glutathione (GSH) content), the drug diffused out the micelles faster. In addition, a slower drug release was noticed for RGD decorated unimolecular micelles.
Finally, the biocompatibility, cytotoxicity, and cellular uptake of the unimolecular micelles were studied. The obtained results were promising as the arborescent unimolecular micelles showed excellent biocompatibility; meanwhile, the DOX-loaded unimolecular micelles have good cytotoxicity compared to free DOX. RGD targeting ligand contributes to increasing the cellular uptake and supports the sustained release.
|
366 |
Structural Characterization of β-Lactoglobulin in Sodium Dodecyl Sulfate and Lauryldimethylamine OxideThompson, Kayla Dawn 10 November 2020 (has links)
No description available.
|
367 |
Solute Partitioning in Elastin-like Polypeptides: A Foundation for Drug Delivery ApplicationsHelm, Eric 24 December 2015 (has links)
No description available.
|
368 |
Étude du mécanisme de protection des spermatozoïdes de mammifères par le laitLusignan, Marie-France 06 1900 (has links)
Le lait écrémé est utilisé depuis plus d’un demi-siècle comme diluant protecteur
des spermatozoïdes de mammifères. Depuis quelques années, il existe une demande
grandissante pour des diluants exempts de produits d’origine animale. Toutefois, le
mécanisme par lequel le lait protège les spermatozoïdes n’est pas connu, ce qui rend
difficile de lui trouver un substitut.
Les protéines majeures du plasma séminal de taureau, les protéines « Binder of
SPerm » (BSP), sont néfastes lors de la conservation de la semence. Les spermatozoïdes
sont en contact avec une grande concentration de protéines BSP qui stimulent une
extraction continuelle de cholestérol/phospholipides de leur membrane plasmique. Les
lipoprotéines de faible densité (LDL) du jaune d’oeuf, un autre composé utilisé dans les
diluants, empêcheraient les protéines BSP de se lier à la membrane des spermatozoïdes de
taureaux et de stimuler un efflux des lipides membranaires, ce qui les protégerait durant la
conservation. Notre hypothèse était que les protéines du lait protègent les spermatozoïdes
durant la conservation en séquestrant les protéines BSP.
Premièrement, nous avons démontré par filtration sur gel qu’il y a une interaction
entre les protéines BSP bovines et les protéines du lait. Le lait écrémé a été fractionné en
trois fractions : F1 (alpha-lactalbumine, bêta-lactoglobuline et caséine kappa), F2 (toutes les
protéines du lait) et F3 (sels, sucres et petits peptides). Les protéines BSP1 et BSP5 ont
une affinité plus grande pour F1 que BSP3, tandis que toutes les protéines BSP ont une
affinité pour F2. Le titrage calorimétrique isotherme a permis de confirmer l’interaction
entre les protéines BSP et les protéines du lait. L’association entre la protéine BSP1
bovine et les micelles de caséines est caractérisée par une constante d’affinité (Ka) de 3.5
× 10^5 M-1 et un paramètre stoichiométrique (n) de 4,5 BSP1 pour une caséine.
L’association entre la protéine BSP1 bovine et l’alpha-lactalbumine (une protéine du sérum
principale), est caractérisée par un Ka de 2.4 × 10^5 M-1 et une valeur “n” de 0,8. Ces
résultats indiquent que le lait protège les spermatozoïdes bovins en séquestrant les
protéines BSP grâce à une interaction protéine : protéine, tandis que le jaune d’oeuf les
protège grâce à une interaction protéine : lipoprotéine. Deuxièmement, nous avons
démontré par filtration sur gel que les protéines homologues aux BSP bovines retrouvées
dans le plasma séminal de porc, d’étalon et de bélier ont une affinité avec les protéines du
lait, ce qui suggère que le mécanisme de protection des spermatozoïdes par le lait pourrait
être le même chez ces espèces. Troisièmement, nous avons caractérisé l’interaction entre
BSP1 bovine et les LDL du jaune d’oeuf qui a un Ka de 3.4 ± 0.4 × 10^6 M-1 et une valeur
de « n » de 104 BSP1 pour une particule de LDL, indiquant qu’il existe des différences
entre le mécanisme de protection des spermatozoïdes par le lait et le jaune d’oeuf.
Nous croyons que les résultats présentés dans cette thèse aideront à créer de
nouveaux diluants ne contenant pas de produits d’origine animale afin de cryoconserver
les spermatozoïdes des mammifères. / Skim milk is being used as a protective agent for mammalian semen conservation
over half a century. Recently, there has been increased interest in developing extenders
free of animal products. However, it is difficult to find suitable component in order to
replace milk as an extender, because the mechanisms by which milk protect sperm against
cooling and freezing damages during the storage is unknown.
The Binder of SPerm (BSP) proteins are the major proteins of bull seminal plasma
and they are harmful during sperm storage. In fact, sperm would be in contact with a large
quantity of BSP proteins that induce a continuous cholesterol and phospholipids efflux
from the sperm membrane during storage. When bull sperm is diluted with an extender
containing egg yolk, another compound frequently used in extender, the low-density
lipoproteins (LDL) present in the egg yolk prevent the binding of the BSP proteins to the
sperm membrane, thus, preventing the lipid efflux from the sperm membrane induced by
the BSP proteins. Our hypothesis was that milk proteins would protect sperm during
storage by binding BSP proteins.
First, we demonstrated by gel filtration that bovine BSP proteins could bind the
milk proteins. Skim milk was fractionated into three fractions: F1 (alpha-lactalbumin and beta-
lactoglobulin, the major whey proteins and kappa-casein), F2 (mainly caseins and all other
milk proteins in small amounts) and F3 (salts, sugars and small peptides). Bovine BSP1
and BSP5 have more affinity for F1 as compared to BSP3 and all the BSP proteins have
affinity for F2. We confirmed the interaction between bovine BSP proteins and milk
proteins by isothermal titration calorimetry. The binding of BSP1 to casein micelles is
characterized by an affinity constant (Ka) of 3.5 × 10^5 M-1 and of a stoichiometric
parameter for the association (n) of 4.5 BSP1 per casein. The association between BSP1
and alpha-lactalbumin (one of the major whey proteins) is characterized by a Ka of 2.4 × 10^5
M-1 and a “n” value of 0.8. These results support our contention that milk can protect
sperm by preventing the BSP proteins’ binding to the sperm membrane attributable to a
protein : protein interaction, while egg yolk sperm protection is attributable to a protein :
lipoprotein interaction. Second, our studies showed that the homologous BSP proteins
found in the boar, stallion and ram seminal plasma can bind the milk proteins. These
results indicate that the mechanism of sperm protection by milk in these species should be
similar to the one in bovine species. Third, we characterized the interaction between
bovine BSP1 protein and LDL from hen’s egg yolk. The binding was characterized by a
Ka of 3.4 ± 0.4 × 10^6 M-1 and a « n » value of 104 BSP1 per LDL particle. Our results
indicated that there is difference between the mechanism of sperm protection by milk and
egg yolk.
We believe that the results presented in this thesis may help to create new
extenders free of animal product for mammal sperm preservation in liquid or frozen state.
|
369 |
Étude des poly(2-alkyl-2-oxazoline)s munis d'extrémités hydrophobes en solution aqueuse et à linterface eau/airEl Hajj Obeid, Rodolphe January 2009 (has links)
Thèse numérisée par la Division de la gestion de documents et des archives de l'Université de Montréal.
|
370 |
Elaboration de nanoparticules de poly (acide lactique) multifonctionnelles comme adjuvants potentiels de vaccinationHandke, Nadege 12 December 2011 (has links)
La vaccination est l’un des moyens les plus efficaces de la médecine moderne dans le combat contre les maladies infectieuses. L’amélioration de l’efficacité des vaccins requiert la mise au point d’adjuvants permettant d’accroître la qualité de la réponse immunitaire. À titre d’exemple, les nanoparticules (NP) de poly(acide lactique) (PLA) constituent un système efficace pour la délivrance d’antigènes. Afin de renforcer leur potentiel vaccinal, ce travail de recherche a eu pour objectif d’élaborer des NP de PLA décorées en surface par des molécules immunostimulantes, le D-mannose ou un peptide dérivé de l’interleukine-Beta, et au cœur, par l’imiquimod. Notre stratégie repose sur l’utilisation d’un tensioactif macromoléculaire composé d’un bloc de PLA et d’un bloc de poly(N-acryloxysuccinimide-co-N-vinylpyrrolidone) (P(NAS-co-NVP)), dont les fonctions ester de N-succinimidyle (NS) permettent le couplage de biomolécules. Ce copolymère a été synthétisé par combinaison de la polymérisation par ouverture de cycle et de la polymérisation radicalaire contrôlée par les nitroxydes (NMP). Après l’étude de la copolymérisation du NAS et de la NVP par NMP à partir d’une alcoxyamine modèle (MAMA-SG1), leur copolymérisation a été réalisée à partir de la macro-alcoxyamine PLA-SG1, conduisant au copolymère PLA-b-P(NAS-co-NVP) désiré. Des NP de PLA ont alors été préparées par nanoprécipitation et diafiltration en présence du copolymère, conduisant à des tailles respectives de 150 et 500 nm. Des études de potentiel zêta et de spectrométrie UV ont démontré la présence des esters de NS à la surface des NP (2.4 fonctions.nm-2), disponibles pour le couplage des biomolécules. Des micelles de copolymère ont été également préparées, après substitution des esters de NS par des sucres, et permettent une encapsulation efficace de l’imiquimod, contrairement aux NP de PLA. Ces systèmes constituent une plateforme flexible d’adjuvants potentiels comme alternative aux adjuvants non biodégradables actuellement utilisés. / Vaccination represents one of the most powerful tools of medicine for the fight against infectious diseases. The improvement of vaccine efficiency needs the development of adjuvants able to increase the quality of the immune response. Poly(lactic acid) (PLA) nanoparticles (NPs) represent an efficient system for antigen delivery. In order to improve their vaccine potential, the goal of this research work was to elaborate PLA NPs decorated at the surface with immunostimulatory molecules, D-mannose or peptide derived from interleukine-Beta, and into the core with imiquimod. Our strategy relies on the use of a macromolecular surfactant composed of a PLA block and a poly(N- acryloxysuccinimide-co-N-vinylpyrrolidone) (P(NAS-co-NVP)) block, whose N-succinimidyl (NS) activated esters allow the coupling of biomolecules. This diblock copolymer was synthesized by the combination of ring opening polymerization and nitroxide mediated polymerization (NMP). After the study of the copolymerization of NAS and NVP by NMP from the MAMA-SG1 model alkoxyamine, their copolymerization was performed from the macro-alkoxyamine PLA-SG1, leading to the desired copolymer PLA-b-P(NAS-co-NVP). PLA NPs were then prepared by nanoprecipitation and diafiltration, in the presence of the copolymer, leading to 150 nm and 500 nm sized particles, respectively. Studies of zeta potential and UV spectrometry demonstrated the presence of NS-activated esters at the NP surface (2.4 functions.nm-2), available for the coupling of biomolecules. Micelles from copolymer were also prepared, after substitution of esters with carbohydrates, and allowed an efficient encapsulation of imiquimod, contrary to PLA NPs. These systems represent a flexible platform of potential adjuvants as an alternative to non-biodegradable adjuvants currently used.
|
Page generated in 0.0451 seconds