Solubilized dialdehyde cellulose (DAC), an efficient crosslinking agent for poly(vinyl alcohol) (PVA), provides less toxic alternative to current synthetic crosslinking agents such as glutaraldehyde, while simultaneously allowing for the preparation of hydrogels with comparably better characteristics. PVA/DAC hydrogels prepared using 0.5, 1 and 1.5 wt% of DAC were analyzed in terms of mechanical, swelling and cytotoxicity characteristics. Materials properties of PVA/DAC hydrogels range from stiff substances to soft viscoelastic gels capable of holding large amounts of water. Superior mechanical properties, porosity and surface area in comparison with analogical PVA/glutaraldehyde hydrogels were observed. Biological studies showed low toxicity and good biocompatibility of PVA/DAC hydrogels. Potential of PVA/DAC in mesh-controlled release of biologically active compounds was investigated using ibuprofen, rutin and phenanthriplatin. Hydrogel loaded with anticancer drug phenantriplatin was found effective against alveolar cancer cell line A549 under in vitro conditions.
- Klíčová slova
- Biomaterials, Crosslinking, Dialdehyde cellulose, Drug release, Hydrogel, Poly(vinyl alcohol),
- MeSH
- biokompatibilní materiály chemie toxicita MeSH
- celulosa analogy a deriváty chemie toxicita MeSH
- fenantridiny chemie MeSH
- hydrogely chemie toxicita MeSH
- ibuprofen chemie MeSH
- lidé MeSH
- modul pružnosti MeSH
- myši MeSH
- nádorové buněčné linie MeSH
- nosiče léků chemie toxicita MeSH
- organoplatinové sloučeniny chemie MeSH
- polyvinylalkohol chemie toxicita MeSH
- reagencia zkříženě vázaná chemie toxicita MeSH
- rutin chemie MeSH
- uvolňování léčiv MeSH
- viskoelastické látky chemie toxicita MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- 2,3-dialdehydocellulose MeSH Prohlížeč
- biokompatibilní materiály MeSH
- celulosa MeSH
- fenantridiny MeSH
- hydrogely MeSH
- ibuprofen MeSH
- nosiče léků MeSH
- organoplatinové sloučeniny MeSH
- phenanthriplatin MeSH Prohlížeč
- polyvinylalkohol MeSH
- reagencia zkříženě vázaná MeSH
- rutin MeSH
- viskoelastické látky MeSH
The purpose of the present work was to evaluate in vivo different antimicrobial therapies to eradicate osteomyelitis created in the femoral head of New Zealand rabbits. Five phosphate-based cements were evaluated: calcium phosphate cements (CPC) and calcium phosphate foams (CPF), both in their pristine form and loaded with doxycycline hyclate, and an intrinsic antimicrobial magnesium phosphate cement (MPC; not loaded with an antibiotic). The cements were implanted in a bone previously infected with Staphylococcus aureus to discern the effects of the type of antibiotic administration (systemic vs. local), porosity (microporosity, i.e. <5 μm vs. macroporosity, i.e. >5 μm) and type of antimicrobial mechanism (release of antibiotic vs. intrinsic antimicrobial activity) on the improvement of the health state of the infected animals. A new method was developed, with a more comprehensive composite score that integrates 5 parameters of bone infection, 4 parameters of bone structural integrity and 4 parameters of bone regeneration. This method was used to evaluate the health state of the infected animals, both before and after osteomyelitis treatment. The results showed that the composite score allows to discern statistically significant differences between treatments that individual evaluations were not able to identify. Despite none of the therapies completely eradicated the infection, it was observed that macroporous materials (CPF and CPFd, the latter loaded with doxycycline hyclate) and intrinsic antimicrobial MPC allowed a better containment of the osteomyelitis. This study provides novel insights to understand the effect of different antimicrobial therapies in vivo, and a promising comprehensive methodology to evaluate the health state of the animals was developed. We expect that the implementation of such methodology could improve the criteria to select a proper antimicrobial therapy.
- Klíčová slova
- Calcium phosphate cements, Calcium phosphate foams, Drug delivery, In vivo, Magnesium phosphate cements, Osteomyelitis,
- MeSH
- antibakteriální látky aplikace a dávkování farmakokinetika farmakologie MeSH
- doxycyklin aplikace a dávkování farmakologie MeSH
- femur diagnostické zobrazování patologie MeSH
- fosforečnany vápenaté chemie MeSH
- implantované léky chemie farmakologie MeSH
- infekční nemoci kostí farmakoterapie terapie MeSH
- kostní cementy chemie farmakologie MeSH
- králíci MeSH
- lékové transportní systémy metody MeSH
- osteomyelitida farmakoterapie terapie MeSH
- poréznost MeSH
- regenerace kostí účinky léků MeSH
- stafylokokové infekce farmakoterapie terapie MeSH
- uvolňování léčiv MeSH
- viskoelastické látky chemie MeSH
- výsledek terapie MeSH
- zvířata MeSH
- Check Tag
- králíci MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- antibakteriální látky MeSH
- calcium phosphate MeSH Prohlížeč
- doxycyklin MeSH
- fosforečnany vápenaté MeSH
- implantované léky MeSH
- kostní cementy MeSH
- viskoelastické látky MeSH
We synthesized Fe foams using water suspensions of micrometric Fe2O3 powder by reducing and sintering the sublimated Fe oxide green body to Fe under 5% H2/Ar gas. The resultant Fe foam showed aligned lamellar macropores replicating the ice dendrites. The compressive behavior and deformation mechanism of the synthesized Fe foam were studied using an acoustic emission (AE) method, with which we detected sudden localized structural changes in the Fe foam material. The evolution of the deformation mechanism was elucidated using the adaptive sequential k-means (ASK) algorithm; specifically, the plastic deformation of the cell struts was followed by localized cell collapse, which eventually led to fracturing of the cell walls. For potential biomedical applications, the corrosion and biocompatibility characteristics of the two synthesized Fe foams with different porosities (50% vs. 44%) were examined and compared. Despite its larger porosity, the superior corrosion behavior of the Fe foam with 50% porosity can be attributed to its larger pore size and smaller microscopic surface area. Based on the cytotoxicity tests for the extracts of the foams, the Fe foam with 44% porosity showed better cytocompatibility than that with 50% porosity.
- Klíčová slova
- Acoustic emission, Biocompatibility, Cellular material, Deformation mechanisms, Iron (oxide),
- MeSH
- akustika * MeSH
- biokompatibilní materiály chemie toxicita MeSH
- buněčné linie MeSH
- difrakce rentgenového záření MeSH
- elektrochemie metody MeSH
- fibroblasty MeSH
- koroze MeSH
- myši MeSH
- pevnost v tlaku MeSH
- poréznost MeSH
- testování materiálů MeSH
- viskoelastické látky chemie MeSH
- železité sloučeniny chemie MeSH
- železo chemie toxicita MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- biokompatibilní materiály MeSH
- ferric oxide MeSH Prohlížeč
- viskoelastické látky MeSH
- železité sloučeniny MeSH
- železo MeSH
A procedure for the preparation of copolymers bearing sulfobetaine and carboxybetaine methacrylic-based monomers by free-radical polymerization is described and discussed. A combination of monomers affects the upper critical solution temperature (UCST) in water and in the presence of a simple NaCl electrolyte while retaining the zwitterionic character. In addition, hydrogel samples were prepared and showed tunable water structure and mechanical properties. The total nonfreezable water content decreases with the amount of carboxybetaine segment in the hydrogel feed and the compression moduli were in a range of 0.7-1.6 MPa. Responses to external conditions such as temperature and ion strength were investigated and a potential application such as modulated thermal detection is proposed. The presence of the carboxylate group in the carboxybetaine segment enables a small fluorescence probe and peptide bearing RDG motif to be attached to polymer and hydrogel samples, respectively. The hydrogel samples functionalized with the RGD motif exhibit controlled cell adhesion. Such synthetic strategy based on combination of different zwitterionic segments offers a simple pathway for the development of zwitterionic materials with programmable properties.
- MeSH
- betain analogy a deriváty chemie MeSH
- buněčná adheze účinky léků MeSH
- buňky 3T3 MeSH
- hydrogely chemická syntéza chemie farmakologie MeSH
- koncentrace vodíkových iontů MeSH
- kyseliny polymethakrylové chemická syntéza chemie farmakologie MeSH
- myši MeSH
- osmolární koncentrace MeSH
- polymerizace MeSH
- tranzitní teplota MeSH
- viskoelastické látky chemická syntéza chemie farmakologie MeSH
- voda chemie MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- betain MeSH
- hydrogely MeSH
- kyseliny polymethakrylové MeSH
- sulfobetaine MeSH Prohlížeč
- viskoelastické látky MeSH
- voda MeSH
This study is devoted to the degradation pathway (bio, photo degradation and photo/bio) of Poly(Lactic acid) PLA polymers by means of melt viscoelasticity. A comparison was made between three PLA polymers with different microstructures (L, D stereoisomers). Biodegradability was determined during composting by burying the polymer films in compost at 58 °C. Melt viscoelasticity was used to assess the molecular evolution of the materials during the composting process. Viscoelastic data were plotted in the complex plane. We used this methodology to check the kinetics of the molecular weight decrease during the initial stages of the degradation, through the evolution of Newtonian viscosity. After a few days in compost, the Newtonian viscosity decreased sharply, meaning that macromolecular chain scissions began at the beginning of the experiments. However, a double molar mass distribution was also observed on Cole⁻Cole plots, indicating that there is also a chain recombination mechanism competing with the chain scission mechanism. PLA hydrolysis was observed by infra-red spectroscopy, where acid characteristic peaks appeared and became more intense during experiments, confirming hydrolytic activity during the first step of biodegradation. During UV ageing, polymer materials undergo a deep molecular evolution. After photo-degradation, lower viscosities were measured during biodegradation, but no significant differences in composting were found.
- Klíčová slova
- PLA, biodegradation, photo-degradation, rheology,
- MeSH
- biodegradace * MeSH
- kinetika MeSH
- molekulová hmotnost MeSH
- polyestery chemie MeSH
- polymery chemie MeSH
- viskoelastické látky chemie MeSH
- viskozita MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- poly(lactide) MeSH Prohlížeč
- polyestery MeSH
- polymery MeSH
- viskoelastické látky MeSH
