Thin composite films comprising two primary representatives of conducting polymers, poly(3, 4-ethylenedioxythiophene) (PEDOT) and polypyrrole (PPy), with eco-friendly cellulose nanocrystals (CNC) were prepared through electrochemical polymerization. The combination of CNC and PEDOT (or PPy) results in the formation of films with highly different surface topography and thickness. Intriguingly, different surface conductivity of PEDOT and PPy was revealed by atomic force microscopy albeit that the electrochemical properties were rather similar. The biological properties of the composites in contact with prospective human induced pluripotent stem cells (hiPSC) and cardiomyocytes derived from hiPSC demonstrated good cytocompatibility of both composites and their potential in engineering of electro-sensitive tissues. The as-prepared conducting, eco-friendly and cytocompatible composites are thus promising candidates for biomedical applications where stimuli-responsivity is a crucial cell-instructive property.
- Klíčová slova
- Cellulose nanocrystals, Human induced pluripotent stem cells, Poly(3,4-ethylenedioxythiophene), Polypyrrole,
- MeSH
- celulosa chemie MeSH
- indukované pluripotentní kmenové buňky * MeSH
- lidé MeSH
- nanočástice * MeSH
- polymery chemie MeSH
- prospektivní studie MeSH
- pyrroly chemie MeSH
- tkáňové inženýrství MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- celulosa MeSH
- polymery MeSH
- pyrroly MeSH
Several studies have reported on application of cellulose particles for stabilizing Pickering emulsions (PE). Here we employ an original approach that involves using these particles as a part of advanced composite colloids made of conducting polymer polyaniline (PANI) and cellulose nanocrystals (CNC) or nanofibrils (CNF). PANI/cellulose particles were prepared using oxidative polymerization of aniline in situ in the presence of CNC or CNF. The type and amount of celluloses (CNC vs CNF) and concentration of precursors (aniline monomer and oxidant) used in the reaction determined properties of the colloidal particles, such as size, morphology and content of PANI. The particles demonstrated intriguing biological characteristics, including no cytotoxicity, antibacterial activity against Staphylococcus aureus and Escherichia coli, antioxidant activity and related immunomodulatory activity. For the first time, such composites were used to successfully stabilize oil-in-water PE with undecane or capric/caprylic triglyceride oils. The properties of the emulsions were determined by the PANI/cellulose particles and oil used. The key finding of the study is the demonstrated ability of PANI/cellulose particles to stabilize PE, as well as the excellent antioxidant activity and ROS scavenging action originating from PANI presence, indicating potential of such systems for use in biomedicine, particularly for wound healing.
- Klíčová slova
- Colloidal dispersions, Conducting polymer, Immunomodulatory activity, Pickering emulsions,
- MeSH
- aniliny farmakologie chemie MeSH
- antioxidancia * farmakologie MeSH
- celulosa * farmakologie chemie MeSH
- emulze chemie MeSH
- Escherichia coli MeSH
- oleje MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- aniline MeSH Prohlížeč
- aniliny MeSH
- antioxidancia * MeSH
- celulosa * MeSH
- emulze MeSH
- oleje MeSH
- polyaniline MeSH Prohlížeč
A green, nature-friendly synthesis of polyaniline colloidal particles based on enzyme-assisted oxidation of aniline with horseradish peroxidase and chitosan or poly(vinyl alcohol) as steric stabilizers was successfully employed. Physicochemical characterization revealed formation of particles containing the polyaniline emeraldine salt and demonstrated only a minor effect of polymer stabilizers on particle morphology. All tested colloidal particles showed in vitro antioxidation activity determined via scavenging of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals. In vitro, they were able to reduce oxidative stress and inhibit the production of reactive oxygen species by neutrophils and inflammatory cytokines by macrophages. The anti-inflammatory effect observed was related to their antioxidant activity, especially in the case of neutrophils. The particles can thus be especially advantageous as active components of biomaterials modulating the early stages of inflammation. In addition to the immunomodulatory effect, the presence of intrinsically conducting polyaniline can impart cell-instructive properties to the particles. The approach to particle synthesis that we employed─an original one using environmentally friendly and biocompatible horseradish peroxidase─represents a smart way of preparing conducting particles with unique properties, which can be further modified by the stabilizers used.
Bio-inspired conductive scaffolds composed of sodium hyaluronate containing a colloidal dispersion of water-miscible polyaniline or polypyrrole particles (concentrations of 0.108, 0.054 and 0.036% w/w) were manufactured. For this purpose, either crosslinking with N-(3-dimethylaminopropyl-N-ethylcarbodiimide hydrochloride and N-hydroxysuccinimid or a freeze-thawing process in the presence of poly(vinylalcohol) was used. The scaffolds comprised interconnected pores with prevailing porosity values of ~ 30% and pore sizes enabling the accommodation of cells. A swelling capacity of 92-97% without any sign of disintegration was typical for all samples. The elasticity modulus depended on the composition of the scaffolds, with the highest value of ~ 50 kPa obtained for the sample containing the highest content of polypyrrole particles. The scaffolds did not possess cytotoxicity and allowed cell adhesion and growth on the surface. Using the in vivo-mimicking conditions in a bioreactor, cells were also able to grow into the structure of the scaffolds. The technique of scaffold preparation used here thus overcomes the limitations of conductive polymers (e.g. poor solubility in an aqueous environment, and limited miscibility with other hydrophilic polymer matrices) and moreover leads to the preparation of cytocompatible scaffolds with potentially cell-instructive properties, which may be of advantage in the healing of damaged electro-sensitive tissues.
- MeSH
- biokompatibilní materiály chemie MeSH
- kyselina hyaluronová MeSH
- polymery * chemie MeSH
- poréznost MeSH
- pyrroly chemie MeSH
- tkáňové inženýrství * metody MeSH
- tkáňové podpůrné struktury chemie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- biokompatibilní materiály MeSH
- kyselina hyaluronová MeSH
- polymery * MeSH
- pyrroly MeSH
The growing application of materials containing TiO2 particles has led to an increased risk of human exposure, while a gap in knowledge about the possible adverse effects of TiO2 still exists. In this work, TiO2 particles of rutile, anatase, and their commercial mixture were exposed to various environments, including simulated gastric fluids and human blood plasma (both representing in vivo conditions), and media used in in vitro experiments. Simulated body fluids of different compositions, ionic strengths, and pH were used, and the impact of the absence or presence of chosen enzymes was investigated. The physicochemical properties and agglomeration of TiO2 in these media were determined. The time dependent agglomeration of TiO2 related to the type of TiO2, and mainly to the type and composition of the environment that was observed. The presence of enzymes either prevented or promoted TiO2 agglomeration. TiO2 was also observed to exhibit concentration-dependent cytotoxicity. This knowledge about TiO2 behavior in all the abovementioned environments is critical when TiO2 safety is considered, especially with respect to the significant impact of the presence of proteins and size-related cytotoxicity.
- Klíčová slova
- TiO2 particles, agglomeration, plasma, proteins, simulated gastric fluids,
- MeSH
- buněčné linie MeSH
- dárci krve MeSH
- fibroblasty účinky léků metabolismus MeSH
- koncentrace vodíkových iontů MeSH
- kovové nanočástice škodlivé účinky chemie MeSH
- krevní plazma metabolismus MeSH
- krystalizace MeSH
- kultivační média metabolismus MeSH
- lidé MeSH
- myši MeSH
- osmolární koncentrace MeSH
- povrchové vlastnosti MeSH
- sliny metabolismus MeSH
- titan škodlivé účinky chemie metabolismus MeSH
- velikost částic MeSH
- viabilita buněk účinky léků MeSH
- voda metabolismus MeSH
- zdraví dobrovolníci pro lékařské studie MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- kultivační média MeSH
- titan MeSH
- titanium dioxide MeSH Prohlížeč
- voda MeSH
Caseinate-stabilized emulsions of black cumin (Nigella sativa) and tamanu (Calophyllum inophyllum) oils were studied in terms of preparation, characterization, and antibacterial properties. The oils were described while using their basic characteristics, including fatty acid composition and scavenging activity. The oil-in-water (o/w) emulsions containing the studied oils were formulated, and the influence of protein stabilizer (sodium caseinate (CAS), 1-12 wt%), oil contents (5-30 wt%), and emulsification methods (high-shear homogenization vs sonication) on the emulsion properties were investigated. It was observed that, under both preparation methods, emulsions of small, initial droplet sizes were predominantly formed with CAS content that was higher than 7.5 wt%. Sonication was a more efficient emulsification procedure and was afforded emulsions with smaller droplet size throughout the entire used concentration ranges of oils and CAS when compared to high-shear homogenization. At native pH of ~ 6.5, all of the emulsions exhibited negative zeta potential that originated from the presence of caseinate. The antibacterial activities of both oils and their emulsions were investigated with respect to the growth suppression of common spoilage bacteria while using the disk diffusion method. The oils and selected emulsions were proven to act against gram positive strains, mainly against Staphylococcus aureus (S. aureus) and Bacillus cereus (B. cereus); regrettably, the gram negative species were fully resistant against their action.
- Klíčová slova
- antibacterial activity, black cumin (Nigella sativa) seed oil, emulsion, formulation, tamanu (Calophyllum inophyllum) seed oil,
- Publikační typ
- časopisecké články MeSH
