Superparamagnetic iron oxide nanoparticles (SPION) with a "non-fouling" surface represent a versatile group of biocompatible nanomaterials valuable for medical diagnostics, including oncology. In our study we present a synthesis of novel maghemite (γ-Fe2O3) nanoparticles with positive and negative overall surface charge and their coating by copolymer P(HPMA-co-HAO) prepared by RAFT (reversible addition-fragmentation chain-transfer) copolymerization of N-(2-hydroxypropyl)methacrylamide (HPMA) with N-[2-(hydroxyamino)-2-oxo-ethyl]-2-methyl-prop-2-enamide (HAO). Coating was realized via hydroxamic acid groups of the HAO comonomer units with a strong affinity to maghemite. Dynamic light scattering (DLS) demonstrated high colloidal stability of the coated particles in a wide pH range, high ionic strength, and the presence of phosphate buffer (PBS) and serum albumin (BSE). Transmission electron microscopy (TEM) images show a narrow size distribution and spheroid shape. Alternative coatings were prepared by copolymerization of HPMA with methyl 2-(2-methylprop-2-enoylamino)acetate (MMA) and further post-polymerization modification with hydroxamic acid groups, carboxylic acid and primary-amino functionalities. Nevertheless, their colloidal stability was worse in comparison with P(HPMA-co-HAO). Additionally, P(HPMA-co-HAO)-coated nanoparticles were subjected to a bio-distribution study in mice. They were cleared from the blood stream by the liver relatively slowly, and their half-life in the liver depended on their charge; nevertheless, both cationic and anionic particles revealed a much shorter metabolic clearance rate than that of commercially available ferucarbotran.
- Publikační typ
- časopisecké články MeSH
Superporous poly(2-hydroxyethyl methacrylate-co-2-aminoethyl methacrylate) (P(HEMA-AEMA)) hydrogel scaffolds are designed for in vitro 3D culturing of leukemic B cells. Hydrogel porosity, which influences cell functions and growth, is introduced by adding ammonium oxalate needle-like crystals in the polymerization mixture. To improve cell vitality, cell-adhesive Arg-Gly-Asp-Ser (RGDS) peptide is immobilized on the N-(γ-maleimidobutyryloxy)succinimide-activated P(HEMA-AEMA) hydrogels via reaction of SH with maleimide groups. This modification is especially suitable for the survival of primary chronic lymphocytic leukemia cells (B-CLLs) in 3D cell culture. No other tested stimuli (interleukin-4, CD40 ligand, or shaking) can further improve B-CLL survival or metabolic activity. Both unmodified and RGDS-modified P(HEMA-AEMA) scaffolds serve as a long-term (70 days) 3D culture platforms for HS-5 and M2-10B4 bone marrow stromal cell lines and MEC-1 and HG-3 B-CLL cell lines, although the adherent cells retain their physiological morphologies, preferably on RGDS-modified hydrogels. Moreover, the porosity of hydrogels allows direct cell lysis, followed by efficient DNA isolation from the 3D-cultured cells. P(HEMA-AEMA)-RGDS thus serves as a suitable 3D in vitro leukemia model that enables molecular and metabolic assays and allows imaging of cell morphology, interactions, and migration by confocal microscopy. Such applications can prospectively assist in testing of drugs to treat this frequently recurring or refractory cancer.
- MeSH
- buněčné kultury metody MeSH
- chronická lymfatická leukemie * MeSH
- hydrogely chemie MeSH
- lidé MeSH
- mezenchymální kmenové buňky MeSH
- nádorové buněčné linie MeSH
- oligopeptidy MeSH
- poréznost MeSH
- sukcinimidy chemie MeSH
- tkáňové podpůrné struktury chemie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
With the aim to develop a new anticancer agent, we prepared poly[N-(2-hydroxypropyl)methacrylamide-co-methyl 2-methacrylamidoacetate] [P(HP-MMAA)], which was reacted with hydrazine to poly[N-(2-hydroxypropyl)methacrylamide-co-N-(2-hydrazinyl-2-oxoethyl)methacrylamide] [P(HP-MAH)] to conjugate doxorubicin (Dox) via hydrazone bond. The resulting P(HP-MAH)-Dox conjugate was used as a coating of magnetic γ-Fe2 O3 nanoparticles obtained by the coprecipitation method. In vitro toxicity of various concentrations of Dox, P(HP-MAH)-Dox, and γ-Fe2 O3 @P(HP-MAH)-Dox nanoparticles was determined on somatic healthy cells (human bone marrow stromal cells hMSC), human glioblastoma line (GaMG), and primary human glioblastoma (GBM) cells isolated from GBM patients both at a short and prolonged exposition time (up to 7 days). Due to hydrolysis of the hydrazone bond in acid milieu of tumor cells and Dox release, the γ-Fe2 O3 @P(HP-MAH)-Dox nanoparticles significantly decreased the GaMG and GBM cell growth compared to free Dox and P(HP-MAH)-Dox in low concentration (10 nM), whereas in hMSCs it remained without effect. γ-F2 O3 @PHP nanoparticles alone did not affect the viability of any of the tested cells.
- MeSH
- akrylamidy chemie MeSH
- doxorubicin chemie metabolismus farmakologie MeSH
- glioblastom patologie MeSH
- lidé MeSH
- magnetické nanočástice chemie MeSH
- nádorové buněčné linie MeSH
- nosiče léků chemie MeSH
- polymery chemie MeSH
- proliferace buněk MeSH
- protinádorové látky chemie metabolismus farmakologie MeSH
- regulace genové exprese u nádorů účinky léků MeSH
- uvolňování léčiv MeSH
- viabilita buněk účinky léků MeSH
- železité sloučeniny chemie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Publikační typ
- abstrakt z konference MeSH
Východiska: Primární lidské B buňky chronické lymfocytární leukemie (CLL) podléhají při kultivaci in vitro buněčné smrti, nicméně jejich přežití lze signifikantně prodloužit kontaktem se stromálními buňkami nebo přítomností specifických solubilních faktorů. Pro účely výzkumu chování CLL buněk jsme vytvořili 3D in vitro model, ve kterém bylo simulováno vhodné mikroprostředí pro CLL buňky umožňující studium mechanizmu jejich přežívání v dlouhodobé kultivaci. Materiál a metody: Naším cílem bylo, aby struktura scaffoldu byla geometricky podobná 3D morfologii kostní dřeně, která vyplňuje trabekulární kost, aby měl 3D scaffold dostatečně velký povrch pro zachycení buněk a zároveň velkou pórovitost pro buněčnou migraci a transport živin. Dalším požadavkem byla také alespoň částečná transparentnost potřebná pro pozorování buněčného modelu pomocí optických metod. Připravili jsme 3D scaffoldy z porózního hydrogelu poly (2-hydroxyetyl metakrylát) (pHEMA), poly (2-hydroxyetyl metakrylát-co-2-aminoetyl metakrylát) p (HEMA-co-AEMA) a p (HEMA-co-AEMA) modifikovaný s často používaným adhezním peptidem Arg-Gly-Asp (RGD). Všechny hydrogelové scaffoldy byly vyrobeny ve čtyřech velikostech pórů (125, 200, 300 a 350–450 μm). Scaffoldy byly testovány pomocí HS-5 buněčné linie odvozené z lidských stromálních buněk kostní dřeně a HEK293 buněčné linie odvozené z lidských embryonálních buněk ledvin. Výsledky: Hydrogelový scaffold p (HEMA-co-AEMA) modifikovaný adhezním peptidem Arg-Gly-Asp (RGD) s velikostí pórů 350–450 μm prokázal, že je vhodným systémem pro 3D kultivace buněk, neboť podporuje interakce mezi buňkami navzájem a také mezi buňkami a materiálem. Tento scaffold byl použit pro nasazení kultivace složené z HS-5 buněk a CLL buněk, které byly stimulovány pomocí ligandu CD40 a cytokinu IL-4. Viabilita CLL buněk byla vyšší v přítomnosti obou stimulátorů zároveň než v případě každého zvlášť. Závěr: Ukázali jsme, že technologie 3D scaffoldů je velmi dobře využitelná pro modelování mikrosystémů, kde se nádorové buňky chovají jako ve svém přirozeném mikroprostředí. Klíčová slova: hematoonkologie – leukemie – hydrogel – stromální buňky
Background: Primary human B cells chronic lymphocytic leukemia undergoes apoptosis, from which they can be rescued by contact with stromal cells or by the addition of specific soluble factor, when cultured in vitro. For research purposes of the behavior of CLL cells we created 3D in vitro model in which we simulated appropriate microenvironment for CLL cells to allow study the mechanism of survival of these cells in long-term cultivation. Material and Methods: Our aim was the scaffold structure to be geometrically similar to the 3D morphology of supporting bone marrow tissue in a trabecular bone; the 3D scaffold was also designed to conform to biocompatibility, sufficiently large surface area for cell attachment, high porosity for cell migration, proliferation and transport of nutrients. Another requirement was a partial transparency for inspection of cell model with optical techniques. We prepared 3D scaffolds from porous hydrogel poly (2-hydroxyethyl methacrylate) (pHEMA), poly (2-hydroxyethyl methacrylate-co-2-aminoethyl methacrylate) p (HEMA-co-AEMA) and p (HEMA-co-AEMA) modified with frequently used cell adhesion peptide Arg-Gly-Asp (RGD). All hydrogel scaffolds were manufactured in four pore diameters (125, 200, 300 and 350–450 μm). Scaffolds were tested with human bone marrow stromal cell line HS-5 and human embryonic kidney cell line HEK293. Results: Hydrogel scaffold p (HEMA-co-AEMA) modified with adhesion peptide Arg-Gly-Asp (RGD) with pore diameter of 350–450 μm demonstrated that it is a convenient system for 3D cell cultivation, since it promotes interaction between the cells and also between the cells and the material. This scaffold was used for seeding of co-cultivation system of HS-5 cells with CLL-cells, which were stimulated through the CD40L signaling pathway as well as via the IL-4 pathway. Viability of B-CLL cells was higher in the presence of both stimulators than with each alone. Conclusions: We have shown that 3D scaffold technology is very useful for modeling of microsystems where the cancer cells behave like in their natural microenvironment. Key words: hematooncology – leukemia – hydrogel – stromal cells This work was supported by grant COST CZ LD15144 “Cellular and acellular grounds for regeneration of bones and teeth” awarded by the Ministry of Education, Youth and Sport of the Czech Republic. The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manuscript met the ICMJE recommendation for biomedical papers. Submitted: 6. 3. 2017 Accepted: 26. 3. 2017
- MeSH
- biokompatibilní materiály MeSH
- biologické modely MeSH
- chronická lymfatická leukemie patologie MeSH
- hydrogely * MeSH
- kultivační techniky metody MeSH
- mezenchymální kmenové buňky MeSH
- nádorové buňky kultivované * MeSH
- nádorové mikroprostředí MeSH
- techniky in vitro MeSH
- tkáňové podpůrné struktury * MeSH
- Publikační typ
- práce podpořená grantem MeSH
Molecular diagnostics may provide tailored and cost efficient treatment for infectious disease and cancer. Rolling circle amplification (RCA) of padlock probes guarantees high specificity to identify nucleic acid targets down to single nucleotide resolution in a multiplex fashion. This makes the assay suitable for molecular analysis of various diseases, and interesting to integrate into automated devices for point-of-care analysis. A critical prerequisite for many molecular assays is (i) target-specific isolation from complex clinical samples and (ii) removal of reagents, inhibitors and contaminants between reaction steps. Efficient solid supports are therefore essential to enable multi-step, multi-analyte protocols. Superparamagnetic micro- and nanoparticles, with large surface area and rapid liquid-phase kinetics, are attractive for multi-step protocols. Recently, streptavidin-modified magnetic monodispersed poly(2-hydroxyethyl methacrylate) (STV-mag.PHEMA) microspheres were developed by multiple swelling polymerization. They are easily separated by a magnet and exhibit low non-specific protein sorption. In this study, the performance and the binding efficiency of STV-mag.PHEMA was addressed by circle-to-circle amplification (C2CA). A lower number of RCA products were detected as compared to the gold standard Dynabeads. Nevertheless, this study was the first to successfully adapt STV-mag.PHEMA microspheres as solid support in a DNA-based protocol, which is an important finding. The STV-mag.PHEMA microspheres were larger with about 16 times less surface area as compared to the Dynabeads, which might partly explain the lower rolling circle product (RCP) count obtained. Further research is currently ongoing comparing particles of similar sizes and optimizing reaction conditions to establish their full utility in the field. Ultimately, low cost and versatile particles are a great resource to facilitate future clinical molecular diagnostics.
- MeSH
- DNA chemie metabolismus MeSH
- imobilizované proteiny chemie metabolismus MeSH
- magnetismus MeSH
- mikrosféry * MeSH
- mikroskopie elektronová rastrovací MeSH
- polyhydroxyethylmethakrylát chemie MeSH
- spektroskopie infračervená s Fourierovou transformací MeSH
- streptavidin chemie metabolismus MeSH
- techniky amplifikace nukleových kyselin MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Three-dimensional hydrogel supports for mesenchymal and neural stem cells (NSCs) are promising materials for tissue engineering applications such as spinal cord repair. This study involves the preparation and characterization of superporous scaffolds based on a copolymer of 2-hydroxyethyl and 2-aminoethyl methacrylate (HEMA and AEMA) crosslinked with ethylene dimethacrylate. Ammonium oxalate is chosen as a suitable porogen because it consists of needle-like crystals, allowing their parallel arrangement in the polymerization mold. The amino group of AEMA is used to immobilize RGDS and SIKVAVS peptide sequences with an N-γ-maleimidobutyryloxy succinimide ester linker. The amount of the peptide on the scaffold is determined using 125 I radiolabeled SIKVAVS. Both RGDS- and SIKVAVS-modified poly(2-hydroxyethyl methacrylate) scaffolds serve as supports for culturing human mesenchymal stem cells (MSCs) and human fetal NSCs. The RGDS sequence is found to be better for MSC and NSC proliferation and growth than SIKVAVS.
- MeSH
- buněčné linie MeSH
- lidé MeSH
- methylmetakryláty chemie farmakologie MeSH
- mezenchymální kmenové buňky cytologie MeSH
- nervové kmenové buňky cytologie metabolismus MeSH
- oligopeptidy * chemie farmakologie MeSH
- tkáňové inženýrství metody MeSH
- tkáňové podpůrné struktury chemie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
A nanobiosensor based on the use of porous magnetic microspheres (PMM) as efficient capturing/pre-concentrating platform is presented for detection of Alzheimer's disease (AD) biomarkers. These PMMs prepared by a multistep swelling polymerization combined with iron oxide precipitation afford carboxyl functional groups suitable for immobilization of antibodies on the particle surface allowing an enhanced efficiency in the capturing of AD biomarkers from human serum samples. The AD biomarkers signaling is produced by gold nanoparticle (AuNP) tags monitored through their electrocatalytic effect towards hydrogen evolution reaction (HER). Novel properties of PMMs in terms of high functionality and high active area available for enhanced catalytic activity of the captured AuNPs electrocatalytic tags are exploited for the first time. A thorough characterization by scanning transmission electron microscope in high angle annular dark field mode (STEM-HAADF) demonstrates the enhanced ability of PMMs to capture a higher quantity of analyte and consequently of electrocatalytic label, when compared with commercially available microspheres. The optimized and characterized PMMs are also applied for the first time for the detection of beta amyloid and ApoE at clinical relevant levels in cerebrospinal fluid (CSF), serum and plasma samples of patients suffering from AD.
- MeSH
- Alzheimerova nemoc diagnóza metabolismus MeSH
- amyloidní beta-protein analýza MeSH
- apolipoproteiny E analýza MeSH
- barvení a značení MeSH
- biologické markery analýza MeSH
- imunomagnetická separace metody MeSH
- katalýza MeSH
- konduktometrie metody MeSH
- kovové nanočástice chemie ultrastruktura MeSH
- lidé MeSH
- mikrosféry MeSH
- poréznost MeSH
- reprodukovatelnost výsledků MeSH
- senzitivita a specificita MeSH
- zlato chemie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The architecture and mechanical properties of a scaffold for spinal cord injury treatment must provide tissue integration as well as effective axonal regeneration. Previous work has demonstrated the cell-adhesive and growth-promoting properties of the SIKVAV (Ser-Ile-Lys-Val-Ala-Val)-modified highly superporous poly(2-hydroxethyl methacrylate) (PHEMA) hydrogels. The aim of the current study was to optimize the porosity and mechanical properties of this type of hydrogel in order to develop a suitable scaffold for the repair of spinal cord tissue. Three types of highly superporous PHEMA hydrogels with oriented pores of ~60 µm diameter, porosities of 57-68% and equivalent stiffness characterized by elasticity moduli in the range 3-45 kPa were implanted into a spinal cord hemisection, and their integration into the host tissue, as well as the extent of axonal ingrowth into the scaffold pores, were histologically evaluated. The best tissue response was found with a SIKVAV-modified PHEMA hydrogel with 68% porosity and a moderate modulus of elasticity (27 kPa in the direction along the pores and 3.6 kPa in the perpendicular direction). When implanted into a spinal cord transection, the hydrogel promoted tissue bridging as well as aligned axonal ingrowth. In conclusion, a prospective oriented scaffold architecture of SIKVAV-modified PHEMA hydrogels has been developed for spinal cord injury repair; however, to develop an effective treatment for spinal cord injury, multiple therapeutic approaches are needed.
- MeSH
- axony patologie MeSH
- biokompatibilní materiály chemie MeSH
- hojení ran MeSH
- hydrogely chemie MeSH
- krysa rodu rattus MeSH
- mechanický stres MeSH
- mezenchymální kmenové buňky cytologie MeSH
- mikroskopie elektronová rastrovací MeSH
- oligopeptidy chemie MeSH
- polyhydroxyethylmethakrylát chemie MeSH
- poranění míchy rehabilitace terapie MeSH
- poréznost MeSH
- potkani Wistar MeSH
- pružnost MeSH
- regenerace nervu MeSH
- tkáňové inženýrství metody MeSH
- tkáňové podpůrné struktury chemie MeSH
- tlak MeSH
- zelené fluorescenční proteiny chemie MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The efficient isolation and concentration of protein antigens from complex biological samples is a critical step in several analytical methods, such as mass spectrometry, flow cytometry and immunochemistry. These techniques take advantage of magnetic microspheres as immunosorbents. The focus of this study was on the development of new superparamagnetic polymer microspheres for the specific isolation of the tumor suppressor protein p53. Monodisperse macroporous poly(glycidyl methacrylate) (PGMA) microspheres measuring approximately 5 μm and containing carboxyl groups were prepared by multistep swelling polymerization of glycidyl methacrylate (GMA), 2-[(methoxycarbonyl)methoxy]ethyl methacrylate (MCMEMA) and ethylene dimethylacrylate (EDMA) as a crosslinker in the presence of cyclohexyl acetate as a porogen. To render the microspheres magnetic, iron oxide was precipitated within their pores; the Fe content in the particles received ∼18 wt%. Nonspecific interactions between the magnetic particles and biological media were minimized by coating the microspheres with poly(ethylene glycol) (PEG) terminated by carboxyl groups. The carboxyl groups of the magnetic PGMA microspheres were conjugated with primary amino groups of mouse monoclonal DO-1 antibody using conventional carbodiimide chemistry. The efficiency of protein p53 capture and the degree of nonspecific adsorption on neat and PEG-coated magnetic microspheres were determined by western blot analysis.
- MeSH
- kyseliny polymethakrylové chemie MeSH
- mikrosféry * MeSH
- myší monoklonální protilátky chemie MeSH
- myši MeSH
- nádorové buněčné linie MeSH
- nádorový supresorový protein p53 chemie izolace a purifikace MeSH
- polyethylenglykoly chemie MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
