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At least 199 records · Page 11Linked to original sources
PubMed2003

PEG with introducer or pull method: a prospective randomized comparison.

BACKGROUND: PEG by the conventional pull method has the potential drawback of being associated with a higher frequency of wound infection, presumably caused by contamination of the gastrostomy catheter as it passes through the oral cavity. This study investigated the occurrence of peristomal wound infection after PEG placement by using the pull and introducer techniques. METHODS: Between September 1999 and May 2002, consecutive patients with dysphagia for whom PEG was recommended were enrolled in the study and randomly assigned to two groups: PEG with the introducer method (Group I) or PEG with the pull method (Group II). The peristomal area of each patient was evaluated on a daily basis for one week after PEG. Erythema and exudate were scored on a scale from 0 to 4 and induration on a scale of 0 to 3. Criteria for infection were a maximum combined score of 8 or higher, or the presence of microscopic and microbiologic evidence of suppurating exudate. In each group, the endoscope was passed once during the procedure, and an antibiotic (piperacillin) was given prophylactically. All procedures were performed by one investigator with the assistance of another physician. RESULTS: Of the 60 patients enrolled, 30 were assigned to each group. PEG was successful in all patients. One patient was excluded from each group because of death (Group I, stroke; Group II, myocardial infarction) within one week of the procedure. Therefore, 58 patients, 29 in each group, were evaluated. There was no significant difference between the groups in terms of clinical parameters (age, gender, disease, performance score, mode of previous feeding, and recent antibiotic exposure). The occurrence of peristomal infection within one week of PEG was lower in Group I (introducer method) (0 vs. 9; p = 0.00094). The mean daily combined scores in Group I were significantly lower than those in Group II. Median of maximum parameter scores in Group I were significantly lower than those in Group II. There were no procedure-related mortalities or clinically significant wound infections that required surgical intervention. CONCLUSIONS: The risk of peristomal wound infection after PEG is lower with the introducer method compared with the pull method.

Aged↗
PubMed2000

Quantitative determination of PEG-hirudin in human plasma using a competitive enzyme-linked immunosorbent assay.

Polyethylene glycol (PEG) coupled r-hirudin mutein is determined by biological methods-the coagulation system. In the present study, a competitive enzyme-linked immunosorbent assay (ELISA) is described that permits the measurement of PEG r-hirudin. The ELISA system adopts a rabbit IgG antibody to quantitatively detect PEG-hirudin in human plasma. A PEG-hirudin calibration curve ranged from 50 to 7000 ng/mL. The limit of detection was 87 ng/mL. The intraassay coefficients of variation (CV) ranged between 16 and 21%, and interassay CV between 8 and 22% for low and high PEG-hirudin concentrations, respectively. The recovery of the compound in plasma was between 96 and 111.5%. The interindividual differences between 100 and 5000 ng/mL PEG-hirudin were between 12 and 22%. The correlation of the concentration of PEG-hirudin determined with the ELISA and the ecarin clotting time was r = 0.902. No interactions between unfractionated heparin, low molecular-weight heparin, or phenprocoumon and PEG-hirudin were observed in the ELISA. Deficiencies of thrombin or antithrombin as well as low, normal, and high fibrinogen levels did not interfere with the assay. It is concluded that the ELISA determines the concentration of PEG-hirudin and is not influenced by other major anticoagulants or by plasma levels of some coagulation proteins.

Calibration↗
PubMed2003

Preparation and characterization of poly(lactic acid)-poly(ethylene glycol)-poly(lactic acid) (PLA-PEG-PLA) microspheres for controlled release of paclitaxel.

Microspheres of a new kind of copolymer, poly(lactic acid)-poly(ethylene glycol)-poly(lactic acid) (PLA-PEG-PLA), are proposed in the present work for clinical administration of an antineoplastic drug paclitaxel with hypothesis that incorporation of a hydrophilic PEG segment within the hydrophobic PLA might facilitate the paclitaxel release. Paclitaxel-loaded PLA-PEG-PLA microspheres of various compositions were prepared by the solvent extraction/evaporation method. Characterization of the microspheres was then followed to examine the particle size and size distribution, the drug encapsulation efficiency, the colloidal stability, the surface chemistry, the surface and internal morphology, the drug physical state and its in vitro release behavior. The effects of polymer types, solvents and drug loading were investigated. It was found that in the microspheres the PEG segment was homogeneously distributed and caused porosity. Significantly faster release from PLA-PEG-PLA microspheres resulted in comparison with the PLGA counterpart. Incorporation of water-soluble solvent acetone in the organic solvent phase further increased the porosity of the PLA-PEG-PLA microspheres and facilitated the drug release. A total of 49.6% sustained release of paclitaxel within 1 month was achieved. Potentially, the presence of PEG on the surface of PLA-PEG-PLA microspheres could improve their biocompatibility. PLA-PEG-PLA microspheres could thus be promising for the clinical administration of highly hydrophobic antineoplastic drugs such as paclitaxel.

Absorbable Implants↗
PubMed1998

Light-induced tailoring of PEG-hydrogel properties.

We have previously reported (Andreopoulos et al. J Am Chem Soc 118 (1996) 6235-6240) the synthesis of hydrogels via the photopolymerization of water-soluble PEG molecules. In this paper, PEG-hydrogel membranes were prepared by the irradiation (> 300 nm) of aqueous solutions of photosensitive 4-armed PEG (nominal molecular weight of 20000), in the absence of photo-initiators. The hydroxyl termini of the PEG's were functionalized with cinnamylidene acetate groups to form photosensitive PEG macromers (PEG-CA), which upon irradiation (>300 nm) formed crosslinks between adjacent cinnamylidene groups resulting in highly crosslinked networks (hydrogels) (Andreopoulos et al. J Am Chem Soc 118 (1996) 6235-6240). The hydrogel membranes were highly swellable with equilibrium volume fractions ranging from 0.02 to 0.05. Their swellability was a function of irradiation light (>300 nm) and degree of modification of the PEG molecules. The effect of light on the permeation fluxes of myoglobin (Mb), hemoglobin (Hb), and lactate dehydrogenase-L (LDH) through PEG membranes was also assessed and the diffusion coefficients of the proteins were determined accordingly. The PEG-CA membranes exhibited photoscissive behavior upon exposure to UV irradiation (254 nm). Therefore, UV light was used as a trigger to control the mesh size of the membranes, and thereby the permeation fluxes of Mb, Hb, and LDH. Equilibrium swelling experiments with membranes prepared under different irradiation conditions were performed, and the Flory-Huggins model was utilized to determine the mesh size and the average molecular weight between crosslinks of the synthesized hydrogels.

Diffusion↗
PubMed1999

Tyrosine-PEG-derived poly(ether carbonate)s as new biomaterials. Part I: synthesis and evaluation.

Tyrosine PEG-derived poly(ether carbonate)s were prepared by condensation copolymerization with phosgene. The resulting polymers were random copolymers with weight average molecular weights from 40 000 to 200 000 dalton. Chemical structure and purity were confirmed by NMR and FTIR spectral analysis. General structure property correlations were established. The glass transition temperature decreased with increasing PEG content and increasing pendent chain length. When higher molecular weight PEG blocks were used, the glass transition temperature increased relative to identical polymers having shorter PEG blocks. The tensile modulus increased with decreasing PEG content, decreasing pendent chain length, and when longer PEG blocks were used. Water uptake and the rate of backbone degradation increased with increasing PEG content. Microspheres could be prepared by solvent evaporation techniques from copolymers with low PEG content. Release rate of pNA and FITC-dextran from the microspheres increased with increasing PEG content. While tyrosine-derived polycarbonates were excellent substrates for cell attachment and growth, the presence of only 5 mol% of PEG1000 led to low or no cell attachment in short-term cell culture with both rat lung fibroblasts and osteoblasts. The polymers were non-cytotoxic.

3T3 Cells↗
PubMed2001

POE-PEG-POE triblock copolymeric microspheres containing protein. II. Polymer erosion and protein release mechanism.

The first paper of this series presented the fabrication and characterization of POE-PEG-POE triblock copolymeric microspheres containing protein. In this paper, we focus on the polymer erosion and the mechanism of protein release. Fourteen-week in vitro behaviors of POE-PEG-POE microspheres loaded with bovine serum albumin (BSA) have been monitored. SEM micrographs reveal that after 14-week incubation in PBS buffer, pH 7.4, 37 degrees C, the polymeric particles remain spherical despite mass loss of almost 90%. On the other hand, molecular weight undergoes a high initial loss of 38% and 44% during the first 2-week incubation for POE-PEG(5%)-POE and POE-PEG(10%)-POE, respectively. Then, it keeps relatively unchanged over 12 weeks. However, POE-PEG(20%)-POE copolymer provides a better compatibility between the POE and PEG blocks. Hydrolysis is homogeneous through the polymer backbone. Thus, its molecular weight remains relatively constant and mass loss shows quite sustained over the 14-week in vitro release. The similar phenomena are observed in the polydispersity index of the degrading copolymers. SDS-PAGE of the encapsulated BSA within the POE-PEG(5%)-POE microspheres displays that the structural integrity of BSA is intact for at least 8 weeks due to a mild environment provided by the copolymer. In addition, XPS and FTIR are utilized to investigate protein behaviors in the degrading microspheres. Protein release from the POE-PEG-POE microspheres shows a biphasic pattern, characterized by an initial stage followed by a non-detectable release. The non-release phase is dominated by either slow polymer degradation or dense microsphere matrix structures. The microsphere formulation is optimized and a sustained protein release over 2 weeks is achieved by using POE-PEG(20%)-POE at a high protein loading.

Animals↗
PubMed1999

A role of cytoskeletal structure of cortical cells in the gravity-regulated formation of a peg in cucumber seedlings.

Seedlings of cucurbitaceous plants develop a protuberant tissue, or peg, on the lower side of the transition region between root and hypocotyl when germinated in a horizontal position. Peg develops due to a change in growth polarity of the cortical cells. We have examined the role of the cytoskeletal structure in peg formation of cucumber seedlings. We observed that in both peg and normal cortical cells of 36 h-old seedlings the microtubules (MTs) were arranged perpendicular to the longitudinal axis of the elongating cells. Application of colchicine perturbed the MTs structure and inhibited the formation of pegs. In 20 h-old seedlings, MTs in cortical cells destined to be a peg tissue had no preferential organization, whereas MTs in normal cortical cells were transversely oriented. After 24 h, the MTs in future peg cells were arranged similar to those of 36 h-old seedlings, although the initiation of peg tissue was not yet visible. These results suggest that reorganization of MTs is required for peg formation and causes the change in growth polarity of the cortical cells.

Cell Polarity↗
PubMedDate not supplied

A method to optimize PEG-coating of red blood cells.

Alloimmunization to donor blood group antigens remains a significant problem in transfusion medicine. A proposed method to overcome donor-recipient blood group incompatibility is to mask the blood group antigens by the covalent attachment of poly(ethylene glycol) (PEG) to the red blood cell (RBC) membrane. Despite much work in the development of PEG-coating of RBCs, there is a paucity of data on the optimization of the PEG-coating technique; it is the aim of this study to determine the optimum conditions for PEG coating using a cyanuric chloride reactive derivative of methoxy-PEG as a model polymer. Activated PEG of molecular mass 5 kDa was covalently attached to human RBCs under various reaction conditions. Inhibition of binding of a blood-type specific antiserum (anti-D) was employed to evaluate the effect of the PEG-coating, quantified by hemocytometry and flow-cytometry. RBC morphology was examined by light and scanning electron microscopy. Statistical analysis of experimental design together with microscopy results showed that the optimum PEGylation conditions are pH = 8.7, temperature = 14 degrees C, and reaction time = 30 min. An optimum concentration of reactive PEG could not be determined. At high polymer concentrations (>25 mg/mL) a predominance of type III echinocytes was observed, and as a result, a concentration of 15 mg/mL is the highest recommended concentration for a linear PEG of molecular mass 5 kDa.

Agglutination↗
PubMed2006

Mechanistic investigations of PEG-directed assembly of one-dimensional ZnO nanostructures.

Mechanistic investigation on spherical assembly of the unique one-dimensional ZnO nanorods, solid nanocones, or hollow prisms with the closed -c end, directed by poly ethylene glycol (PEG) with different molecular weights, has been carried out using spectroscopic methods. The single crystalline ZnO nanoprisms, hollow along the c axis but closed at the -c end, aggregate to urchin-type globules in the microscale when PEG 2000 is used as directing reagent, while spherical aggregates of single crystalline ZnO nanocones are obtained under the direction of PEG 200. Studies reveal that both the PEG molecules aggregate to globules by interacting with zinc species in suitable solvents and englobe the zinc species. By the short time of ultrasonic pretreatment on the solution, a kind of flagellum structure is induced around the globules, in long tubular shapes for PEG 2000 but as shorter wedges for PEG 200. The globules with flagellums are templates for the assembly of the ZnO nanotubes or ZnO nanocones in the hydrothermal treatment. The tiny ZnO crystallites, produced in the hydrothermal process, stack to the templates and amalgamate to single crystalline nanotubes or nanocones, similar to the oriented attachment mechanism. The PEG 2000 template is included in the ZnO cavity of nanotubes, while PEG 200 is excluded from the ZnO nanocones due to the different intertwist properties between the two PEG molecules. Both the urchin-type assemblies, possessing the same external crystalline plane, compose a isotropic powder and emit very strong yellow light, centered at approximately 2.1 eV, under the excitation of the He-Cd laser at 325 nm, which has been correlated to the specific crystal plane. The special powders will be easily coated onto any type of surface for the decoration of a large area of surfaces for future applications.

Journal Article↗
PubMed2003

Force enhancement by PEG during ramp stretches of skeletal muscle.

We have investigated the effects of a stronger actomyosin bond on force (Ps) during rapid stretch of active permeabilized rabbit psoas muscle fibers as a function of temperature from 5 to 30 degrees C. The strength of the actomyosin bond is enhanced by addition of polyethylene glycol (PEG), especially in pre-powerstroke states [Chinn et al. (2000) Biophys J 49: 437-451]. We have hypothesized that such states produce much of the force when activated muscles are stretched [Getz et al. (1998) Biophys J 75: 2971-2983]. Addition of PEG to activated fibers produced a small increase in isometric tension, Po (50-90 kN/m2), which was approximately independent of temperature. In contrast PEG produced a dramatic increase in Ps at low temperatures (200-300 kN/m2), but a modest increase at higher temperatures (70-90 kN/m2). We also measured Ps and Po in solutions containing the phosphate analog aluminum fluoride (AlF4) with and without PEG. In the absence of PEG, AlF4 reduced Po much more than Ps. Addition of PEG did not enhance Po, but enhanced Ps significantly. The contrasting effects of PEG on Ps and Po, and the effect of temperature can be explained by a model in which stretch force is produced by pre-powerstroke cross-bridges whose maximum distension is increased by PEG, and isometric force is produced by strongly bound cross-bridges whose bond strength is also enhanced by PEG, but to a lesser extent.

Actomyosin↗
PubMed2001

The effect of a microgravity (space) environment on the expression of expansins from the peg and root tissues of Cucumis sativus.

In young cucumber seedlings, the peg is a polar outgrowth of tissue that functions by snagging the seed coat, thereby freeing the cotyledons. The development of the peg is thought to be gravity-dependent and has become a model system for plant-gravity response. Peg development requires rapid cell expansion, a process thought to be catalyzed by alpha-expansins, and thus was a good system to identify expansins that were regulated by gravity. This study identified 7 new alpha-expansin cDNAs from cucumber seedlings (Cucumis sativus L. cv Burpee Hybrid II) and examined their expression patterns. Two alpha-expansins (CsExp3 and CsExp4) were more highly expressed in the peg and the root. Earlier reports stated that pegs tend not to form in the absence of gravity, so the expression levels were compared in the pegs of seedlings grown in space (STS-95), on a clinostat, and on earth (1 g). Pegs were observed to form at high frequency on clinostat and space-grown seedlings, yet on clinostats there was more than a 4-fold reduction in the expression of CsExp3 in the pegs of seedlings grown on clinostats vs. those grown at 1 g, while the CsExp4 gene appeared to be turned off (below detection limits). There were no detectable differences in expansin gene expression levels for the pegs of seedlings grown in space or in the orbiter environmental simulator (OES) (1 g) at NASA. The microgravity environment did not affect the expression of CsExp3 or CsExp4, and the clinostat did not simulate the microgravity environment well.

Cucumis sativus↗
PubMed2001

PEG adsorption of autoantibodies and detection of alloantibodies in warm autoimmune hemolytic anemia.

BACKGROUND: The purpose of this study was to evaluate the effectiveness of PEG in the adsorption of autoantibodies and the detection of alloantibodies in patients with warm autoimmune hemolytic anemia (WAIHA). STUDY DESIGN AND METHODS: The study was divided into three parts. First, the effectiveness of antibody removal by a conventional adsorption procedure and that by the PEG adsorption method were compared by using commercial antisera adsorbed with antigen-positive RBCs. Second, patients' sera with known weak alloanti-E were used to test against screening cells after allogeneic adsorption to show nonspecific coating of antibodies and the dilution effect on the PEG adsorption procedure. Third, conventional and PEG one-cell sample allogeneic adsorptions of WAIHA patients' sera with and without alloantibodies were performed and compared. RESULTS: In the first part, seven of the eight polyclonal antisera gave a lower titer and score when tested against antigen-positive RBCs in the indirect antiglobulin test; this indicated that PEG is more efficient in removing antibodies. In the second part, similar reaction patterns were observed in antibody screening tests on unadsorbed sera and on sera after the first, second, and third adsorptions, which indicated that there was no alloantibody loss, nonspecific antibody coating, or dilution effect when PEG was added in the allogeneic adsorption procedures. In the third part, a 40-percent increase in efficiency in reducing the number of adsorptions and an 85-percent decrease in completion time of the adsorption procedures were obtained when PEG was used for adsorbing sera from 16 patients with WAIHA. Both conventional and PEG procedures were capable of removing autoantibodies to identify the specificities of alloantibodies. CONCLUSION: The PEG adsorption method is an effective, sensitive, and efficient method of enhancing auto- antibody adsorption and alloantibody detection. It can reduce the processing time and minimize the delay of urgent transfusions to patients with WAIHA and can indirectly enhance cost-effectiveness and decrease the labor-intensive testing required by these cases.

Anemia, Hemolytic↗
PubMed1997

Modified barium swallow does not affect how often PEGs are placed after stroke.

Dysphagia frequently follows stroke, but often resolves quickly. Percutaneous endoscopic gastrostomy (PEG) or other feeding tubes are placed to improve nutrition and hydration, and reduce the risk of aspiration pneumonitis. We evaluated the impact of modified barium swallow in determining PEG placements and the influence of specific swallowing abnormalities on PEG placement. The abnormalities assessed were presence of pharyngeal stasis and/or visualization of posterior pharyngeal transfer problems and aspiration of liquid or solids. A total of 302 patients with stroke were admitted to our hospital between 1989 and 1993, but only those with hemorrhagic or nonhemorrhagic stroke by computed tomographic (CT) scans or magnetic resonance imaging (MRI) or autopsy were included in our study. Patients with transient ischemic attacks (TIAs), central nervous system tumors, and traumas were excluded. Barium swallow studies were performed on 69 (23%) of patients; 49 (71%) were abnormal, based on aspiration of barium, pharyngeal stasis, or postpharyngeal transfer dysphagia. PEGs were placed in only 18% of those with abnormal studies. Of the patients with normal barium swallow studies, 25% had a PEG placed. Two hundred thirty-three patients underwent no barium swallow studies, but 11 (4.72%) of these had PEG placed. The rate of PEG placement was not related to any one of the abnormalities noted on the modified barium swallow. Rather, patients who received PEG had significant neurological deficits and increased prevalence of aspiration pneumonitis. The decision to insert PEG was made on clinical grounds and not on abnormal barium studies alone.

Aged↗
PubMed2003

Prosthetic motility in pegged versus unpegged integrated porous orbital implants.

PURPOSE: To objectively measure and compare prosthetic motility in pegged versus unpegged orbital implants and to determine subjective patient assessment of motility after the pegging procedure. METHODS: A prospective case series of 10 patients with integrated porous orbital implants, who had secondary motility peg placement procedure, were studied. Infrared oculography was used to quantitatively assess pegged and unpegged prosthetic eye motility in horizontal and vertical excursions. RESULTS: For horizontal excursions, prosthetic motility in unpegged implants retained an average of 49.6% of measured motility of the contralateral normal eye, which increased to 86.5% with peg placement (P<0.05). For vertical excursions, prosthetic motility in unpegged implants retained an average of 51.3% of measured motility of the contralateral normal eye, which increased to 54.3% with peg placement (P>0.3). Nine of 10 patients judged their motility as "significantly improved," and 1 patient gave a rating of "some improvement" after peg placement. Four of 10 patients had granulomas around the peg sites. CONCLUSIONS: Objective assessment of prosthetic motility shows a significant increase in horizontal gaze after motility peg placement.

Adult↗
PubMedDate not supplied

A novel approach to re-pegging hydroxyapatite implants using bioactive glass.

PURPOSE: To determine if bioactive glass, originally designed for craniomaxillofacial use, can be used effectively for re-pegging of hydroxyapatite orbital implants. METHODS: Over a 2-year period, 3 patients with pegged hydroxyapatite orbital implants and related complications that did not respond to conservative treatment, underwent removal of the implant pegs and/or sleeves. Peg tracts were subsequently filled with bioactive glass. RESULTS: No complications occurred in any case during 3 years of follow-up. After 2 months, 2 patients underwent successful re-drilling of the peg site and insertion of titanium pegs. Both patients were satisfied with the results. The third patient has deferred re-pegging at this time. CONCLUSION: Bioactive glass is effective for refilling old peg tracts and allowing timely re-pegging of hydroxyapatite implants.

Adolescent↗
PubMed2007

Tolerability and patient acceptance of sodium phosphate tablets compared with 4-L PEG solution in colon cleansing: combined results of 2 identically designed, randomized, controlled, parallel group, multicenter phase 3 trials.

GOALS: Evaluate patient tolerance and acceptance of a sodium phosphate (NaP) tablet purgative compared with a 4-L polyethylene glycol (PEG) solution. BACKGROUND: Characteristics and side effects of bowel purgatives deter patients from undergoing screening colonoscopy. Published data demonstrated comparable bowel cleansing with NaP tablets and a 4-L PEG solution in 2 phase for 3 studies. This report presents data on patient tolerability and acceptance. STUDY: Two identically designed, randomized, investigator-blinded, and multicenter trials were performed. Tolerability and patient acceptance were based on purgative regimen compliance, incidence of gastrointestinal adverse events, and patient responses to questionnaires. RESULTS: Eight hundred forty-five patients were assessed (420 and 425 in the tablet and PEG solution groups, respectively). Patient compliance with the tablet regimen was greater: 94% of patients took all the tablets compared with 57% completing the PEG solution regimen (P<0.0001). Nausea, vomiting, and bloating occurred significantly less often in patients taking NaP tablets (P<0.0001). Among patients taking tablets, 88.4% rated them "easy" or "slightly difficult" to take, compared with 60.6% of patients taking the PEG solution. The preparation's taste was rated "barely tolerable" or "not tolerable" by 1% of patients treated with NaP tablets and 23.6% treated with PEG solution. Drinking the required volume of clear liquid for the tablet or PEG preparation was rated "easy" or "slightly difficult" by 92.2% and 66.9% of patients, respectively. Almost all (90.7%) patients taking the tablets indicated they would take the same preparation in the future, compared with 67.1% of patients taking the PEG solution (P<0.0001 for each comparison). CONCLUSIONS: Tolerability and patient acceptance of a NaP tablet purgative were superior to 4-L PEG solution.

Administration, Oral↗
PubMedDate not supplied

Intestinal passage of the PEG end-piece: is it safe?

Two rare but life-threatening complications of percutaneous endoscopic gastrostomy (PEG) are reported: small bowel perforation and obstruction. Both resulted from impaction of the PEG end-piece after separation at skin level. Review of the literature revealed very few complications from intestinal passage of PEG end-pieces. The free intragastric PEG end-piece routinely passes through the gastrointestinal tract in most cases. One of these two cases was drawn from a series of 100 patients with intentional intestinal passage of PEG end-pieces to give a severe complication rate of 1%. A case can be made for routine endoscopic per-oral removal of PEG end-pieces in the elective setting, but this is more costly and not without hazard. Previous laparotomy and/or known adhesions is a relative indication for endoscopic retrieval of the PEG end-piece. Oesophageal disease or intolerance of endoscopy is a relative indication for intestinal passage. Close clinical follow up is recommended to ensure that the PEG end-piece has passed per-rectum. If the PEG end-piece has not passed and is shown in the small bowel on plain X-ray at approximately 3 weeks after separation then lodgement has probably occurred and early operative intervention is warranted.

Aged↗
PubMed1999

Preparation of PEG-coated surfaces and a study for their interaction with living cells.

Cell-biomaterial interaction is of great importance for the development of bioinert as well as of hybrid surfaces. This study represents our results of human fibroblast interaction with PEG-coated surfaces of differing length and structure (linear or branched) of the oxyethylene chain. We employed three PEGs -- PEG 1500 and PEG 6000, both lineal but with different chain lengths, and PEG 12500 which was branched. The PEGs were deposited on silica plates using branched poly(ethylene imine) as an anchoring polymer. Fibroblasts were plated and studied by immunofluorescence to evaluate the overall cell morphology, the organisation of the actin cytoskeleton, and the beta1-integrin (fibronectin receptor). The particular effect of fibronectin (FN) pre-adsorption was studied. Our results suggest that PEG 6000 surface is to be preferable with respect to the initial interaction with the cells. The overall cell morphology was almost normal on bare surfaces. FN pre-coating additionally improved cell adhesion and spreading as well as the organization of the actin cytoskeleton and focal adhesion formation; the PEG 12500 surface showed relatively poor initial properties. Almost no cell spreading was found on the bare surface, but FN pre-adsorption completely restored normal cell morphology. In contrast, PEG 1500 had to be considered is 'the worst' material, because of lower initial cell adhesion and spreading and FN pre-adsorption did not restore normal cell morphology.

Adsorption↗