Polymer layers capable of suppressing protein adsorption from biological media while presenting extracellular matrix-derived peptide motifs offer valuable new options for biomimetic surface engineering. Herein, we provide detailed insights into physicochemical changes induced in a nonfouling poly(ethylene oxide) (PEO) brush/polydopamine (PDA) system by incorporation of adhesion ligand (RGD) peptides. Brushes with high surface chain densities (σ ≥ 0.5 chains·nm-2) and pronounced hydrophilicity (water contact angles ≤ 10°) were prepared by end-tethering of heterobifunctional PEOs ( Mn ≈ 20 000 g·mol-1) to PDA-modified surfaces from a reactive melt. Using alkyne distal end group on the PEO chains, azidopentanoic-bearing peptides were coupled through a copper-catalyzed Huisgen azide-alkyne "click" cycloaddition reaction. The surface concentration of RGD was tuned from complete saturation of the PEO surface with peptides (1.7 × 105 fmol·cm-2) to values which may induce distinct differences in cell adhesion (<6.0 × 102 fmol·cm-2). Infrared reflection-absorption and X-ray photoelectron spectroscopies proved the PDA-PEO layers covalent structure and the immobilization of RGD peptides. The complete reconstruction of experimental electrohydrodynamics data utilizing mean-field theory predictions further verified the attained brush structure of the end-tethered PEO chains which provided hydrodynamic screening of the PDA anchor. Increasing the surface concentration of immobilized RGD peptides led to increased interfacial charging. Supported by simulations, this observation was attributed to the ionization of functional groups in the amino acid sequence and to the pH-dependent adsorption of water ions (OH- > H3O+) from the electrolyte. Despite the distinct differences observed in the electrokinetic analysis of the surfaces bearing different amounts of RGD, it was found that the peptide presence on PEO(20 000)-PDA layers does not have a significant effect on the nonfouling properties of the system. Notably, the presented PEO(20 000)-PDA layers bearing RGD peptides in the surface concentration range 5.9 to 1.7 × 105 fmol·cm-2 reduced the protein adsorption from fetal bovine serum to less than 30 ng·cm-2, that is, values comparable to the ones obtained for pristine PEO(20 000)-PDA layers.000)-PDA layers bearing RGD peptides in the surface concentration range 5.9 to 1.7 x 105 fmol.cm-2 reduced the protein adsorption from fetal bovine serum to less than 30 ng.cm-2, that is, values comparable to the ones obtained for pristine PEO(20 000)-PDA layers.

• MeSH
• adsorpce MeSH
• buněčná adheze MeSH
• fotoelektronová spektroskopie MeSH
• molekulární struktura MeSH
• peptidy * chemie   MeSH
• polyethylenglykoly * chemie   MeSH
• povrchové vlastnosti MeSH

In this study, fibrous scaffolds based on poly(γ-benzyl-l-glutamate) (PBLG) were investigated in terms of the chondrogenic differentiation potential of human tooth germ stem cells (HTGSCs). Through the solution-assisted bonding of the fibres, fully connected scaffolds with pore sizes in the range 20-400 µm were prepared. Biomimetic modification of the PBLG scaffolds was achieved by a two-step reaction procedure: first, aminolysis of the PBLG fibres' surface layers was performed, which resulted in an increase in the hydrophilicity of the fibrous scaffolds after the introduction of N5 -hydroxyethyl-l-glutamine units; and second, modification with the short peptide sequence azidopentanoyl-GGGRGDSGGGY-NH2 , using the 'click' reaction on the previously modified scaffold with 2-propynyl side-chains, was performed. Radio-assay of the 125 I-labelled peptide was used to evaluate the RGD density in the fibrous scaffolds (which varied in the range 10-3 -10 pm/cm2 ). All the PBLG scaffolds, especially with density 90 ± 20 fm/cm2 and 200 ± 100 fm/cm2 RGD, were found to be potentially suitable for growth and chondrogenic differentiation of HTGSCs. Copyright © 2015 John Wiley & Sons, Ltd.

• MeSH
• benzylové sloučeniny chemická syntéza   chemie   farmakologie   MeSH
• chrupavka účinky léků   fyziologie   MeSH
• click chemie MeSH
• dítě MeSH
• glutamáty chemická syntéza   chemie   farmakologie   MeSH
• glykosaminoglykany metabolismus   MeSH
• kmenové buňky cytologie   účinky léků   MeSH
• kultivované buňky MeSH
• lidé MeSH
• magnetická rezonanční spektroskopie MeSH
• mladiství MeSH
• peptidy farmakologie   MeSH
• povrchové vlastnosti MeSH
• proliferace buněk účinky léků   MeSH
• tkáňové inženýrství metody   MeSH
• tkáňové podpůrné struktury chemie   MeSH
• viabilita buněk účinky léků   MeSH
• zubní zárodek cytologie   MeSH
• Check Tag
• dítě MeSH
• lidé MeSH
• mladiství MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Thermally induced phase separation (TIPS) based methods are widely used for the fabrication of porous scaffolds for tissue engineering and related applications. However, formation of a less-/non-porous layer at the scaffold's outer surface at the air-liquid interface, often known as the skin-effect, restricts the cell infiltration inside the scaffold and therefore limits its efficacy. To this end, we demonstrate a TIPS-based process involving the exposure of the just quenched poly(lactide-co-caprolactone):dioxane phases to the pure dioxane for a short time while still being under the quenching strength, herein after termed as the second quenching (2Q). Scanning electron microscopy, mercury intrusion porosimetry and contact angle analysis revealed a direct correlation between the time of 2Q and the gradual disappearance of the skin, followed by the widening of the outer pores and the formation of the fibrous filaments over the surface, with no effect on the internal pore architecture and the overall porosity of scaffolds. The experiments at various quenching temperatures and polymer concentrations revealed the versatility of 2Q in removing the skin. In addition, the in vitro cell culture studies with the human primary fibroblasts showed that the scaffolds prepared by the TIPS based 2Q process, with the optimal exposure time, resulted in a higher cell seeding and viability in contrast to the scaffolds prepared by the regular TIPS. Thus, TIPS including the 2Q step is a facile, versatile and innovative approach to fabricate the polymer scaffolds with a skin-free and fully open porous surface morphology for achieving a better cell response in tissue engineering and related applications.

• MeSH
• analýza selhání vybavení MeSH
• biokompatibilní materiály chemická syntéza   MeSH
• chemická frakcionace metody   MeSH
• design vybavení MeSH
• polyestery chemie   MeSH
• polymery chemie   MeSH
• poréznost MeSH
• povrchové vlastnosti MeSH
• testování materiálů MeSH
• tkáňové inženýrství přístrojové vybavení   metody   MeSH
• tkáňové podpůrné struktury * MeSH
• vytápění metody   MeSH
• změna skupenství MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

We present an investigation of the preparation of highly porous hydrogels based on biodegradable synthetic poly(α-amino acid) as potential tissue engineering scaffolds. Covalently cross-linked gels with permanent pores were formed under cryogenic conditions by free-radical copolymerization of poly[N(5)-(2-hydroxyethyl)-L-glutamine-stat-N(5)-(2-methacryloyl-oxy-ethyl)-L-glutamine] (PHEG-MA) with 2-hydrohyethyl methacrylate (HEMA) and, optionally, N-propargyl acrylamide (PrAAm) as minor comonomers. The morphology of the cryogels showed interconnected polyhedral or laminar pores. The volume content of communicating water-filled pores was >90%. The storage moduli of the swollen cryogels were in the range of 1-6 kPa, even when the water content was >95%. The enzymatic degradation of a cryogel corresponded to the decrease in its storage modulus during incubation with papain, a model enzyme with specificity analogous to wound-healing enzymes. It was shown that cryogels with incorporated alkyne groups can easily be modified with short synthetic peptides using azide-alkyne cycloaddition "click" chemistry, thus providing porous hydrogel scaffolds with biomimetic features.

• MeSH
• akrylamidy chemie   MeSH
• aminokyseliny chemie   MeSH
• biokompatibilní materiály chemie   MeSH
• biomimetika MeSH
• click chemie * MeSH
• kryogely chemie   MeSH
• methakryláty chemie   MeSH
• morfinany chemie   MeSH
• peptidy chemie   MeSH
• polymerizace MeSH
• polymery chemie   MeSH
• poréznost MeSH
• tkáňové inženýrství MeSH
• tkáňové podpůrné struktury chemie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Protein-repulsive surfaces modified with ligands for cell adhesion receptors have been widely developed for controlling the cell adhesion and growth in tissue engineering. However, the question of matrix production and deposition by cells on these surfaces has rarely been addressed. In this study, protein-repulsive polydopamine-poly(ethylene oxide) (PDA-PEO) surfaces were functionalized with an RGD-containing peptide (RGD), with a collagen-derived peptide binding fibronectin (Col), or by a combination of these peptides (RGD + Col, ratio 1:1) in concentrations of 90 fmol/cm(2) and 700 fmol/cm(2) for each peptide type. When seeded with vascular endothelial CPAE cells, the PDA-PEO surfaces proved to be completely non-adhesive for cells. On surfaces with lower peptide concentrations and from days 1 to 3 after seeding, cell adhesion and growth was restored practically only on the RGD-modified surface. However, from days 3 to 7, cell adhesion and growth was improved on surfaces modified with Col and with RGD + Col. At higher peptide concentrations, the cell adhesion and growth was markedly improved on all peptide-modified surfaces in both culture intervals. However, the collagen-derived peptide did not increase the expression of fibronectin in the cells. The deposition of fibronectin on the material surface was generally very low and similar on all peptide-modified surfaces. Nevertheless, the RGD + Col surfaces exhibited the highest cell adhesion stability under a dynamic load, which correlated with the highest expression of talin and vinculin in the cells on these surfaces. A combination of RGD + Col therefore seems to be the most promising for surface modification of biomaterials, e.g. vascular prostheses.

• MeSH
• adsorpce MeSH
• biomimetika * MeSH
• buněčná adheze * MeSH
• exprese genu MeSH
• fibronektiny chemie   genetika   MeSH
• indoly chemie   MeSH
• kultivované buňky MeSH
• lidé MeSH
• molekulární sekvence - údaje MeSH
• oligopeptidy chemie   MeSH
• polyethylenglykoly chemie   MeSH
• polymery chemie   MeSH
• povrchové vlastnosti MeSH
• sekvence aminokyselin MeSH
• talin genetika   MeSH
• vinkulin genetika   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

We report on the design and fabrication of a frame-supported nanofibrous membrane for the transplantation of retinal pigment epithelial (RPE) cells, which is a promising therapeutic option for the treatment of degenerative retinal disorders. The membranous cell carrier prepared from 640 nm-thick poly(DL-lactide) fibres uniquely combines high porosity, large pore size and low thickness, to maximize the nutrient supply to the transplanted cells in the subretinal space and thus to enhance the therapeutic effect of the transplantation. The carrier was prepared by electrospinning, which made it easy to embed a 95 μm-thick circular supporting frame 2 mm in diameter. Implantations into enucleated porcine eyes showed that the frame enabled the ultrathin membrane to be handled without irreversible folding, and allowed the membrane to regain its flat shape when inserted into the subretinal space. We further demonstrated that the minimum membrane thickness compatible with the surgical procedure and instrumentation employed here was as low as 4 μm. Primary porcine RPE cells cultivated on the membranes formed a confluent monolayer, expressed RPE-specific differentiation markers and showed transepithelial resistance close to that of the native RPE. Most importantly, the majority of the RPE cells transplanted into the subretinal space remained viable. The ultrathin, highly porous, and surgically convenient cell carrier presented here has the potential to improve the integration and the functionality of transplanted RPE cells.

• MeSH
• 3D tisk MeSH
• analýza selhání vybavení MeSH
• design vybavení MeSH
• epitelové buňky cytologie   transplantace   MeSH
• kultivované buňky MeSH
• membrány umělé * MeSH
• nanovlákna chemie   ultrastruktura   MeSH
• pokovování galvanické metody   MeSH
• polymery chemie   MeSH
• poréznost MeSH
• prasata MeSH
• proliferace buněk MeSH
• retinální pigmentový epitel cytologie   transplantace   MeSH
• tkáňové podpůrné struktury * MeSH
• transplantace buněk přístrojové vybavení   MeSH
• viabilita buněk MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The replacement of pancreatic islets for the possible treatment of type 1 diabetes is limited by the extremely high oxygen demand of the islets. To this end, here we hypothesize to create a novel extra-hepatic highly-vascularized bioartificial cavity using a porous scaffold as a template and using the host body as a living bioreactor for subsequent islet transplantation. Polylactide-based capsular-shaped anisotropic channeled porous scaffolds were prepared by following the unidirectional thermally-induced phase separation technique, and were implanted under the skin and in the greater omentum of Brown Norway rats. Polyamide mesh-based isotropic regular porous capsules were used as the controls. After 4weeks, the implants were excised and analyzed by histology. The hematoxylin and eosin, as well as Masson's trichrome staining, revealed a) low or no infiltration of giant inflammatory cells in the implant, b) minor but insignificant fibrosis around the implant, c) guided infiltration of host cells in the test capsule in contrast to random cell infiltration in the control capsule, and d) relatively superior cell infiltration in the capsules implanted in the greater omentum than in the capsules implanted under the skin. Furthermore, the anti-CD31 immunohistochemistry staining revealed numerous vessels at the implant site, but mostly on the external surface of the capsules. Taken together, the current study, the first of its kind, is a significant step-forward towards engineering a bioartificial microenvironment for the transplantation of islets.

• MeSH
• anizotropie MeSH
• antigeny CD31 MeSH
• buněčné mikroprostředí MeSH
• fibróza MeSH
• fyziologická neovaskularizace účinky léků   MeSH
• krysa rodu rattus MeSH
• kyselina mléčná chemie   MeSH
• kyselina polyglykolová chemie   MeSH
• Langerhansovy ostrůvky * MeSH
• poréznost MeSH
• potkani inbrední BN MeSH
• tkáňové podpůrné struktury MeSH
• tobolky MeSH
• transplantace Langerhansových ostrůvků metody   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

In this study, we investigate the preparation of surface pattern of functional groups on poly(lactide) (PLA) surfaces through the controlled deposition of core-shell self-assemblies based on functionalized PLA-b-PEO amphiphilic block copolymers from selective solvents. Through grafting RGDS peptide onto the functionalized copolymer surface, the presented approach enables to prepare PLA surfaces with random and clustered spatial distribution of adhesive motifs. The proposed topography of the adhesion motif was proved by atomic force microscopy techniques using biotin-tagged RGDS peptide grafted on the surface and streptavidin-modified gold nanospheres which bind the tagged RGDS peptides as a contrast agent. The cell culture study under static and dynamic conditions with MG63 osteosarcoma cell line showed that the clustered distribution of RGDS peptides provided more efficient initial cell attachment and spreading, and resistance to cell detachment under dynamic culture compared to randomly distributed RGDS motif when with the same average RGDS peptide concentration.

• MeSH
• biomimetika MeSH
• buněčná adheze účinky léků   MeSH
• kovové nanočástice MeSH
• laktáty chemie   MeSH
• lidé MeSH
• mikroskopie atomárních sil MeSH
• nádorové buněčné linie MeSH
• nanostruktury chemie   MeSH
• oligopeptidy MeSH
• polyethylenglykoly chemie   MeSH
• povrchové vlastnosti MeSH
• streptavidin chemie   MeSH
• vazba proteinů MeSH
• zlato MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The design of favorable mechanical properties and suitable surface modifications of hydrogels in order to stimulate specific cell response is a great challenge. N-(2-Hydroxypropyl) methacryl-amide (HPMA) was utilized to form macroporous cryogel scaffolds for stem cell applications. Furthermore, one group of scaffolds was enhanced by copolymerization of HPMA with methacryloyl-GGGRGDS-OH peptide in an effort to integrate biomimetic adhesion sites. The cryogels were characterized by stiffness and equilibrium swelling measurements as well as by scanning electron microscopy. Cell culture experiments were performed with human adipose-derived stem cells and substrates were found completely non-toxic. Moreover, RGDS-enriched cryogels supported cell attachment, spreading and proliferation, so they can be considered suitable for designed aims.

• MeSH
• akrylamidy * MeSH
• biokompatibilní materiály MeSH
• biomimetika * MeSH
• buněčná adheze MeSH
• kmenové buňky * MeSH
• kryogely MeSH
• kultivované buňky MeSH
• lidé MeSH
• poréznost MeSH
• proliferace buněk MeSH
• pružnost MeSH
• tkáňové podpůrné struktury MeSH
• tukové buňky MeSH
• voda chemie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

In a typical cell culture system, growth factors immobilized on the cell culture surfaces can serve as a reservoir of bio-signaling molecules, without the need to supplement them additionally into the culture medium. In this paper, we report on the fabrication of albumin/heparin (Alb/Hep) assemblies for controlled binding of basic fibroblast growth factor (FGF-2). The surfaces were constructed by layer-by-layer adsorption of polyelectrolytes albumin and heparin and were subsequently stabilized by covalent crosslinking with glutaraldehyde. An analysis of the surface morphology by atomic force microscopy showed that two Alb/Hep bilayers are required to cover the surface of substrate. The formation of the Alb/Hep assemblies was monitored by the surface plasmon resonance (SPR), the infrared multiinternal reflection spectroscopy (FTIR MIRS) and UV/VIS spectroscopy. The adsorption of FGF-2 on the cross-linked Alb/Hep was followed by SPR. The results revealed that FGF-2 binds to the Alb/Hep assembly in a dose and time-dependent manner up to the surface concentration of 120 ng/cm(2). The bioactivity of the adsorbed FGF-2 was assessed in experiments in vitro, using calf pulmonary arterial endothelial cells (CPAE). CPAE cells could attach and proliferate on Alb/Hep surfaces. The adsorbed FGF-2 was bioactive and stimulated both the proliferation and the differentiation of CPAE cells. The improvement was more pronounced at a lower FGF-2 surface concentration (30 ng/cm(2)) than on surfaces with a higher concentration of FGF-2 (120 ng/cm(2)).

• MeSH
• albuminy farmakologie   MeSH
• buněčná adheze účinky léků   MeSH
• buněčná diferenciace účinky léků   MeSH
• buněčné kultury metody   MeSH
• endoteliální buňky cytologie   MeSH
• fibroblastový růstový faktor 2 metabolismus   farmakologie   MeSH
• heparin farmakologie   MeSH
• kultivační média chemie   MeSH
• lidé MeSH
• mikroskopie atomárních sil MeSH
• proliferace buněk účinky léků   MeSH
• skot MeSH
• vazba proteinů MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• skot MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH