The extracellular matrix (ECM) plays a crucial role in organoid cultures by supporting cell proliferation and differentiation. A key feature of the ECM is its mechanical influence on the surrounding cells, directly affecting their behavior. Matrigel, the most commonly used ECM, is limited by its animal-derived origin, batch variability, and uncontrollable mechanical properties, restricting its use in 3D cell-model-based mechanobiological studies. Poly(2-alkyl-2-oxazoline) (PAOx) synthetic hydrogels represent an appealing alternative because of their reproducibility and versatile chemistry, enabling tuning of hydrogel stiffness and functionalization. Here, we studied PAOx hydrogels with differing compressive moduli for their potential to support 3D cell growth. PAOx hydrogels support spheroid and organoid growth over several days without the addition of ECM components. Furthermore, we discovered intestinal organoid epithelial polarity reversion in PAOx hydrogels and demonstrate how the tunable mechanical properties of PAOx can be used to study effects on the morphology and oxygenation of live multicellular spheroids.
- Publikační typ
- časopisecké články MeSH
In recent years, polymerization-induced self-assembly (PISA) has emerged as a powerful method for the straightforward synthesis of polymer nanoparticles at high concentration. In this study, we describe for the first time the synthesis of poly(2-oxazoline) nanoparticles by dispersion cationic ring-opening polymerization-induced self-assembly (CROPISA) in n-dodecane. Specifically, a n-dodecane-soluble aliphatic poly(2-(3-ethylheptyl)-2-oxazoline) (PEHOx) block was chain-extended with poly(2-phenyl-2-oxazoline) (PPhOx). While the PhOx monomer is soluble in n-dodecane, its polymerization leads to n-dodecane-insoluble PPhOx, which leads to in situ self-assembly of the formed PEHOx-b-PPhOx copolymers. The polymerization kinetics and micellization upon second block formation were studied, and diverse nanoparticle dispersions were prepared, featuring varying block lengths and polymer concentrations, leading to dispersions with distinctive morphologies and physical properties. Finally, we developed a single-step protocol for the synthesis of polymer nanoparticles directly from monomers via gradient copolymerization CROPISA, which exploits the significantly greater reactivity of EHOx compared to that of PhOx during the statistical copolymerization of both monomers. Notably, this approach provides access to formulations with monomer compositions otherwise unattainable through the block copolymerization method. Given the synthetic versatility and application potential of poly(2-oxazolines), the developed CROPISA method can pave the way for advanced nanomaterials with favorable properties as demonstrated by using the obtained nanoparticles for stabilization of Pickering emulsions.
- Klíčová slova
- CROP, Copolymerization, Nanoparticles, PISA, Poly(2-oxazoline)s,
- Publikační typ
- časopisecké články MeSH
Surface functionalization with biological macromolecules is an important task for the development of sensor materials, whereby the interaction with other biological materials should be suppressed. In this work, we developed a novel multifunctional poly(2-ethyl-2-oxazoline)-dithiolane conjugate as a versatile linker for gold surface immobilization of amine-containing biomolecules, containing poly(2-ethyl-2-oxazoline) as antifouling polymer, dithiolane for surface immobilization, and activated esters for protein conjugation. First, a well-defined carboxylic acid containing copoly(2-ethyl-2-oxazoline) was synthesized by cationic ring-opening copolymerization of 2-ethyl-2-oxazoline with a methyl ester-containing 2-oxazoline monomer, followed by postpolymerization modifications. The side-chain carboxylic groups were then converted to amine-reactive pentafluorophenyl (PFP) ester groups. Part of the PFP groups was used for the attachment of the dithiolane moiety, which can efficiently bind to gold surfaces. The final copolymer contained 1.4 mol% of dithiolane groups and 4.5 mol% of PFP groups. The copolymer structure was confirmed by several analytical techniques, including NMR spectroscopy and size-exclusion chromatography. The kinetics of the PFP ester aminolysis and hydrolysis demonstrated significantly faster amidation compared to hydrolysis, which is essential for subsequent protein conjugation. Successful coating of gold surfaces with the polymer was confirmed by spectroscopic ellipsometry, showing a polymer brush thickness of 4.77 nm. Subsequent modification of the coated surfaces was achieved using bovine serum albumin as a model protein. This study introduces a novel reactive polymer linker for gold surface functionalization and offers a versatile polymer platform for various applications including biosensing and surface functionalization.
Aqueous solutions of some polymers exhibit a lower critical solution temperature (LCST); that is, they form phase-separated aggregates when heated above a threshold temperature. Such polymers found many promising (bio)medical applications, including in situ thermogelling with controlled drug release, polymer-supported radiotherapy (brachytherapy), immunotherapy, and wound dressing, among others. Yet, despite the extensive research on medicinal applications of thermoresponsive polymers, their biodistribution and fate after administration remained unknown. Thus, herein, they studied the pharmacokinetics of four different thermoresponsive polyacrylamides after intramuscular administration in mice. In vivo, these thermoresponsive polymers formed depots that subsequently dissolved with a two-phase kinetics (depot maturation, slow redissolution) with half-lives 2 weeks to 5 months, as depot vitrification prolonged their half-lives. Additionally, the decrease of TCP of a polymer solution increased the density of the intramuscular depot. Moreover, they detected secondary polymer depots in the kidneys and liver; these secondary depots also followed two-phase kinetics (depot maturation and slow dissolution), with half-lives 8 to 38 days (kidneys) and 15 to 22 days (liver). Overall, these findings may be used to tailor the properties of thermoresponsive polymers to meet the demands of their medicinal applications. Their methods may become a benchmark for future studies of polymer biodistribution.
- Klíčová slova
- LCST, biodistribution, poly(2,2-difluoroethyl)acrylamide, poly(N,N-diethylacrylamide), poly(N-acryloylpyrolidine), poly(N-isopropylacrylamide), polyacrylamide, rational polymer design,
- MeSH
- myši MeSH
- polymery * MeSH
- teplota MeSH
- tkáňová distribuce MeSH
- uvolňování léčiv MeSH
- voda * MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- polymery * MeSH
- voda * MeSH
Naturally occurring oligoamines, such as spermine, spermidine, and putrescine, are well-known regulators of gene expression. These oligoamines frequently have short alkyl spacers with varying lengths between the amines. Linear polyethylenimine (PEI) is a polyamine that has been widely applied as a gene vector, with various formulations currently in clinical trials. In order to emulate natural oligoamine gene regulators, linear random copolymers containing both PEI and polypropylenimine (PPI) repeat units were designed as novel gene delivery agents. In general, statistical copolymerization of 2-oxazolines and 2-oxazines leads to the formation of gradient copolymers. In this study, however, we describe for the first time the synthesis of near-ideal random 2-oxazoline/2-oxazine copolymers through careful tuning of the monomer structures and reactivity as well as polymerization conditions. These copolymers were then transformed into near-random PEI-PPI copolymers by controlled side-chain hydrolysis. The prepared PEI-PPI copolymers formed stable polyplexes with GFP-encoding plasmid DNA, as validated by dynamic light scattering. Furthermore, the cytotoxicity and transfection efficiency of polyplexes were evaluated in C2C12 mouse myoblasts. While the polymer chain length did not significantly increase the toxicity, a higher PPI content was associated with increased toxicity and also lowered the amount of polymers needed to achieve efficient transfection. The transfection efficiency was significantly influenced by the degree of polymerization of PEI-PPI, whereby longer polymers resulted in more transfected cells. Copolymers with 60% or lower PPI content exhibited a good balance between high plasmid-DNA transfection efficiency and low toxicity. Interestingly, these novel PEI-PPI copolymers revealed exceptional serum tolerance, whereby transfection efficiencies of up to 53% of transfected cells were achieved even under 50% serum conditions. These copolymers, especially PEI-PPI with DP500 and a 1:1 PEI/PPI ratio, were identified as promising transfection agents for plasmid DNA.
- MeSH
- aziridiny MeSH
- DNA * chemie MeSH
- myši MeSH
- plazmidy genetika MeSH
- polyethylenimin chemie MeSH
- polymery * chemie MeSH
- technika přenosu genů MeSH
- transfekce MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- aziridine MeSH Prohlížeč
- aziridiny MeSH
- DNA * MeSH
- polyethylenimin MeSH
- polymery * MeSH
Amphiphilic gradient copolymers represent a promising alternative to extensively used block copolymers due to their facile one-step synthesis by statistical copolymerization of monomers of different reactivity. Herein, an in-depth analysis is provided of micelles based on amphiphilic gradient poly(2-oxazoline)s with different chain lengths to evaluate their potential for micellar drug delivery systems and compare them to the analogous diblock copolymer micelles. Size, morphology, and stability of self-assembled nanoparticles, loading of hydrophobic drug curcumin, as well as cytotoxicities of the prepared nanoformulations are examined using copoly(2-oxazoline)s with varying chain lengths and comonomer ratios. In addition to several interesting differences between the two copolymer architecture classes, such as more compact self-assembled structures with faster exchange dynamics for the gradient copolymers, it is concluded that gradient copolymers provide stable curcumin nanoformulations with comparable drug loadings to block copolymer systems and benefit from more straightforward copolymer synthesis. The study demonstrates the potential of amphiphilic gradient copolymers as a versatile platform for the synthesis of new polymer therapeutics.
- Klíčová slova
- gradient copolymers, nanomedicine, poly(2-oxazoline)s, self-assembly,
- MeSH
- hydrofobní a hydrofilní interakce MeSH
- kurkumin * chemie MeSH
- micely * MeSH
- nosiče léků chemie MeSH
- polymery chemie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- kurkumin * MeSH
- micely * MeSH
- nosiče léků MeSH
- polymery MeSH
The use of fluorinated contrast agents in magnetic resonance imaging (MRI) facilitates improved image quality due to the negligible amount of endogenous fluorine atoms in the body. In this work, we present a comprehensive study of the influence of the amphiphilic polymer structure and composition on its applicability as contrast agents in 19F MRI. Three series of novel fluorine-containing poly(2-oxazoline) copolymers and terpolymers, hydrophilic-fluorophilic, hydrophilic-lipophilic-fluorophilic, and hydrophilic-thermoresponsive-fluorophilic, with block and gradient distributions of the fluorinated units, were synthesized. It was discovered that the CF3 in the 2-(3,3,3-trifluoropropyl)-2-oxazoline (CF3EtOx) group activated the cationic chain end, leading to faster copolymerization kinetics, whereby spontaneous monomer gradients were formed with accelerated incorporation of 2-methyl-2-oxazoline or 2-n-propyl-2-oxazoline with a gradual change to the less-nucleophilic CF3EtOx monomer. The obtained amphiphilic copolymers and terpolymers form spherical or wormlike micelles in water, which was confirmed using transmission electron microscopy (TEM), while small-angle X-ray scattering (SAXS) revealed the core-shell or core-double-shell morphologies of these nanoparticles. The core and shell sizes obey the scaling laws for starlike micelles predicted by the scaling theory. Biocompatibility studies confirm that all copolymers obtained are noncytotoxic and, at the same time, exhibit high sensitivity during in vitro 19F MRI studies. The gradient copolymers provide the best 19F MRI signal-to-noise ratio in comparison with the analogue block copolymer structures, making them most promising as 19F MRI contrast agents.
- MeSH
- difrakce rentgenového záření MeSH
- fluor * MeSH
- maloúhlový rozptyl MeSH
- micely * MeSH
- polymery MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- fluor * MeSH
- micely * MeSH
- polymery MeSH
Buckminsterfullerene (C60) has a large potential for biomedical applications. However, the main challenge for the realization of its biomedical application potential is to overcome its extremely low water solubility. One approach is the coformulation with biocompatible water-soluble polymers, such as poly(2-oxazoline)s (PAOx), to form water-soluble C60 nanoparticles (NPs). However, uniform and defined NPs have only been obtained via a thin film hydration method or using cyclodextrin-functionalized PAOx. Here, we report the mechanochemical preparation of defined and stable C60:PAOx NPs by the introduction of a simple alkyne group as a polymer end-group. The presence of this alkyne bond is proven to be crucial in the mechanochemical synthesis of stable, defined sub-100 nm C60:PAOx NPs, with high C60 content up to 8.9 wt %.
- Publikační typ
- časopisecké články MeSH
Herein, we describe a new method for the synthesis of superhydrophilic poly(2-alkyl-2-oxazoline)s (PAOx) from poly(2-ethyl-2-oxazoline) (PEtOx). A well-defined linear polyethylenimine was prepared from PEtOx by controlled acidic hydrolysis of its side-chains followed by reacylation with different carboxylic acids. Using this protocol, we obtained a series of new hydrophilic PAOx containing side-chain ether groups with potential in biomaterials science. The relative hydrophilicity of the polymers was assessed, revealing that poly(2-methoxymethyl-2-oxazoline) (PMeOMeOx) is the most hydrophilic PAOx reported to date. Additionally, the amorphous poly(2-methoxy-ethoxy-ethoxymethyl-2-oxazoline) (PDEGOx) shows the lowest reported glass transition temperature (-25 °C) within the PAOx family to date. The biomedical potential of the prepared polymers was further fortified by an in vitro cytotoxicity study, where all polymers appeared to be noncytotoxic. The described synthetic protocol is universal and can be extremely versatile, especially for PAOx that are difficult to prepare by conventional cationic ring-opening polymerization due to the monomer interference and/or degradation.
- MeSH
- HeLa buňky MeSH
- hydrofobní a hydrofilní interakce MeSH
- lidé MeSH
- oxazoly chemie MeSH
- polyethylenimin chemie MeSH
- tranzitní teplota MeSH
- vitrifikace MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- oxazoly MeSH
- poly(2-oxazoline) MeSH Prohlížeč
- polyethylenimin MeSH
The synthesis of defined triphilic terpolymers with hydrophilic, lyophilic, and fluorophilic blocks is an important challenge as a basis for the development of multicompartment self-assembled structures with potential for, e.g., cascade catalysis and multidrug loading. The synthesis of fluorophilic poly(2-oxazoline)s generally suffers from a very low reactivity of fluorinated 2-oxazoline monomers in cationic ring-opening polymerization (CROP). We report a systematic study on overcoming the extremely low reactivity of 2-perfluoroalkyl-2-oxazolines in CROP by the insertion of methyl and ethyl hydrocarbon spacers between the 2-oxazoline ring and the trifluoromethyl group. The kinetic studies showed the gradual increase of the rate of polymerization with increasing of the hydrocarbon spacer length. The monomer with an ethyl spacer was found to have similar reactivity as 2-alkyl-2-oxazolines and allowed the synthesis of defined triphilic triblock copolymers.
- Publikační typ
- časopisecké články MeSH
