Macroporous hydrogels are artificial biomaterials commonly used in tissue engineering, including central nervous system (CNS) repair. Their physical properties may be modified to improve their adhesion properties and promote tissue regeneration. We implanted four types of hydrogels based on 2-hydroxyethyl methacrylate (HEMA) with different surface charges inside a spinal cord hemisection cavity at the Th8 level in rats. The spinal cords were processed 1 and 6 months after implantation and histologically evaluated. Connective tissue deposition was most abundant in the hydrogels with positively-charged functional groups. Axonal regeneration was promoted in hydrogels carrying charged functional groups; hydrogels with positively charged functional groups showed increased axonal ingrowth into the central parts of the implant. Few astrocytes grew into the hydrogels. Our study shows that HEMA-based hydrogels carrying charged functional groups improve axonal ingrowth inside the implants compared to implants without any charge. Further, positively charged functional groups promote connective tissue infiltration and extended axonal regeneration inside a hydrogel bridge.

• MeSH
• biokompatibilní materiály terapeutické užití   MeSH
• hrudní obratle zranění   patologie   MeSH
• hydrogely terapeutické užití   MeSH
• krysa rodu Rattus MeSH
• methakryláty terapeutické užití   MeSH
• poranění míchy patologie   terapie   MeSH
• poréznost MeSH
• potkani Wistar MeSH
• povrchové vlastnosti MeSH
• regenerace nervu * MeSH
• řízená tkáňová regenerace metody   MeSH
• statická elektřina MeSH
• testování materiálů MeSH
• výsledek terapie MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• biokompatibilní materiály MeSH
• hydrogely MeSH
• hydroxyethyl methacrylate MeSH Prohlížeč
• methakryláty MeSH

Four series of macroporous hydrogels based on crosslinked copolymers of 2-hydroxyethyl methacrylate (HEMA)-sodium methacrylate (MANa), copolymer HEMA-[2-(methacryloyloxy)ethyl]trimethylammonium chloride (MOETACl), terpolymer HEMA-MANa-MOETACl and on a polyelectrolyte complex were used as carriers for immobilization of proteins, chicken egg white albumin and avidin. The adsorption capacity of the hydrogels for the two proteins, kinetics and pH dependence of albumin adsorption and desorption were studied. The morphology of the hydrogels with and without immobilized albumin was studied by low-vacuum scanning electron microscopy.

• MeSH
• adsorpce MeSH
• albuminy analýza   chemie   ultrastruktura   MeSH
• avidin analýza   chemie   ultrastruktura   MeSH
• biokompatibilní potahované materiály analýza   chemie   MeSH
• hydrogely analýza   chemie   MeSH
• kinetika MeSH
• methakryláty analýza   chemie   MeSH
• poréznost MeSH
• povrchové vlastnosti MeSH
• testování materiálů MeSH
• vazba proteinů MeSH
• Publikační typ
• časopisecké články MeSH
• hodnotící studie MeSH
• práce podpořená grantem MeSH
• srovnávací studie MeSH
• Názvy látek
• albuminy MeSH
• avidin MeSH
• biokompatibilní potahované materiály MeSH
• hydrogely MeSH
• hydroxyethyl methacrylate MeSH Prohlížeč
• methakryláty MeSH

Crosslinked macroporous hydrogels based on 2-hydroxyethyl methacrylate (HEMA)-[2-(methacryloyloxy)ethyl]trimethylammonium chloride (MOETACl) copolymer, HEMA-MOETACl-methacrylic acid (MA) terpolymer, and on a polyelectrolyte complex of HEMA-MA copolymer with poly(MOETACl) were prepared. All the hydrogels were prepared in the presence of fractionated sodium chloride particles. The hydrogels were characterized by the number of pores and the total volume of all pores in unit volume, the average volume and the average diameter of single pore. Morphology of the hydrogels was investigated by confocal and scanning electron microscopy. The hydrogels based on polyelectrolyte complexes were also characterized by chemical composition. Homogeneous (non-porous) hydrogels with the same composition as macroporous hydrogels were prepared and characterized by their biocompatibility.

• MeSH
• biokompatibilní materiály analýza   chemie   farmakologie   MeSH
• elektrolyty analýza   chemie   MeSH
• hydrogely analýza   chemie   farmakologie   MeSH
• krysa rodu Rattus MeSH
• makromolekulární látky analýza   chemie   MeSH
• methakryláty analýza   chemie   farmakologie   MeSH
• pojivová tkáň účinky léků   ultrastruktura   MeSH
• polymery analýza   chemie   MeSH
• poréznost MeSH
• povrchové vlastnosti MeSH
• statická elektřina MeSH
• testování materiálů MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• hodnotící studie MeSH
• práce podpořená grantem MeSH
• srovnávací studie MeSH
• Názvy látek
• biokompatibilní materiály MeSH
• elektrolyty MeSH
• hydrogely MeSH
• hydroxyethyl methacrylate MeSH Prohlížeč
• makromolekulární látky MeSH
• methakryláty MeSH
• polymery MeSH

This study compares subcutaneous and intracerebral biocompatibilty of two hydrogels: copolymer of 2-hydroxyethyl methacrylate with 2-(methylsulfanyl)ethyl methacrylate and poly(2-hydroxyethyl methacrylate) as reference polymer. The experimental copolymer was more biologically inert than poly(2-hydroxyethyl methacrylate) in both the studied parameters, hence the former material is a suitable candidate for biomedical application.

• Publikační typ
• časopisecké články MeSH

Interaction of organism with non-toxic implanted polymers depends on the physicochemical properties of the implant surface, which influence the adsorption of bioactive proteins and subsequently adhesion and growth of cells. The synthetic hydrogels are known as poorly adhesive surfaces. In this study we demonstrated the adsorption of albumin, fibrinogen, fibronectin, basic fibroblast growth factor, heparin-binding epidermal growth factor-like growth factor and epidermal growth factor to poly(2-hydroxyethyl methacrylate) (pHEMA) and copolymer of 2-hydroxyethyl methacrylate (HEMA) and potassium salt of 3-sulfopropyl methacrylate (SPMAK). The adhesion and growth of 3T3 cells and human keratinocytes on surface of these polymers was tested without and with pretreatment of polymers with heparin-binding epidermal growth factor-like growth factor. The adhesion of mixture of human granulocytes and monocytes to these surfaces was also tested. The strips of both polymers were subcutaneously and intracerebrally implanted into the rat and the extent of foreign body reaction and brain biocompatibility was evaluated. The results showed the extensive adsorption of basic fibroblast growth factor and heparin-binding epidermal growth factor-like growth factor to copolymer containing SPMAK. However the adhesion (and growth) of cells to this type of copolymers was very low. Preadsorption of human plasma to pHEMA clearly stimulated the leukocyte adhesion in contrary to copolymer containing SPMAK. The extent of foreign-body reaction was significantly higher against the pHEMA compared to tested copolymer p(HEMA-co-SPMAK). In conclusion, the tested copolymer was a poorly adhesive substrate that is only poorly recognized by the non-specific immunity, although the adsorption of basic growth factors to this substrate is highly significant. Both polymers were well tolerated by the brain tissue. The phenotype of surrounding neurons was more close to the control neurons in the brain tissue surrounding the p(HEMA-co-SPMAK) implants.

• Publikační typ
• časopisecké články MeSH

A lesion in the dorsoposterior part of the rat brain septum is known to exert an inhibitory effect on the delayed skin hypersensitivity and incorporation of radiolabeled thymidine into the lymphoid organs. To determine whether distinct properties of macrophages will also be modulated by this type of injury, we have focused upon the monitoring of expression of sugar receptors (lectins). In this study we show a reduction in the number of macrophages expressing carbohydrate-binding sites for asialoglycoproteins (beta-D-galactoside), alpha-D-mannoside and alpha-D-mannoside-6-phosphate in spleen macrophages after the lesion of the dorsoposterior septum of the brain in the rat. The number of ED-1+ macrophages was not influenced. The intraperitoneal injection of beads prepared from the copolymer of 2-hydroxyethyl methacrylate with dimethyl aminoethyl methacrylate (30 wt %) elevated significantly the number of ED-1+ spleen macrophages and number of macrophages with binding site(s) recognizing asialoglycoproteins and alpha-D-mannoside-6-phosphate, respectively. These results indicate that a foreign-body reaction appears to be able to mediate a phenotypic restoration of lectin expression by spleen macrophages altered by the brain lesion. It can be suggested that, for example, a probable production of cytokines by the inflammatory cells colonizing the implanted beads plays a role in this process.

• Publikační typ
• časopisecké články MeSH

Structural changes of polyethylene (PE), induced by irradiation with 40 keV Ar+ ions at a fluence of 1x10(12)-1x10(15) cm(-2), are characterized by different experimental methods and physical parameters of the modified PE are related to its biocompatibility. Production of oxidized structures and conjugated double bonds in the PE surface layer modified by the ion irradiation was proved using IR, UV-VIS spectroscopies and a Rutherford backscattering technique. The fusion of macrophages onto implants made of as-irradiated and chemically doped PE was studied in vivo. It was found that the free surface energy is not a decisive factor affecting the non-self-recognition of the modified PE by macrophages. The fusion of macrophages, however, was found to be different on the as-irradiated specimens and the specimens additionally doped with acrylic acid.

• Publikační typ
• časopisecké články MeSH

Blood platelet and monocyte adhesion was studied in vitro with respect to the influence of hydrophilic polymer chemical functional groups and their charge. The results showed that the strongest adhesion of human monocytes was to coverslips covered with cationic polymer. Platelet adhesion to all tested polymers proved to be negligible; no differences related to the charge of the polymers used were observed. These results show the obvious difference between the biocompatibility and haemocompatibility in vitro which must be taken into consideration during polymer biological properties testing before clinical trials.

• Publikační typ
• časopisecké články MeSH