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PubMed1997

Silicone rubber-hydrogel composites as polymeric biomaterials. IX. Composites containing powdery polyacrylamide hydrogel.

A composite material has been prepared consisting of a silicone rubber matrix and particulate lightly cross-linked polyacrylamide hydrogel. The material, resembling common silicone rubber, is hydrophilic and swells in water like hydrogels. The polyacrylamide has a high specific surface area, a relatively low content of water-soluble low-molecular-weight compounds and, owing to its non-ionogenic character, a pH-independent swelling degree. For the composite material consisting of the silicone rubber and very fine powdery cross-linked polyacrylamide, we have measured the rate of swelling in water, the mechanical properties (tensile strength, break elongation, hardness, resilience), biological properties (implantation test, cytotoxicity, cell cultivation) and UV absorption of its water extracts. The polyacrylamide and polysiloxane purity, as the composite material starting components, has been determined to be satisfactory. As a result, a high swelling rate of the prepared composite material has been observed, resulting in reaching more than 70% wt of water of the equilibrium swelling. The results show that the composite material is suitable for biological and medical use.

3T3 Cells↗
PubMed2005

Efficacy and safety of polyacrylamide hydrogel for facial soft-tissue augmentation.

BACKGROUND: Polyacrylamide is a nonabsorbable soft-tissue filler that has been used for body contouring for more than 10 years. Aquamid is a soft-tissue filler containing polyacrylamide hydrogel. Safety and aesthetic results after injection of polyacrylamide hydrogel for facial soft-tissue enhancement were assessed at a 1-year follow-up. METHODS: In a prospective, multicenter study, 251 patients were enrolled and assigned for injection of polyacrylamide hydrogel (Aquamid) as a means of facial augmentation and enhancement of facial contours. Subjects with facial contour deformities or soft-tissue deficiencies caused by aging, acne, trauma, surgery, or other causes were included. Persons presenting with connective tissue disorders, skin disorders affecting the face, uncontrolled diabetes mellitus, compromised immune functions or acute inflammatory diseases, known substance abuse, or mental disorders were excluded from participation in the study, as were those who had experienced treatment with any nonabsorbable filler within 6 months before the start of the study. To assess the safety and efficacy of the treatment, follow-up visits were scheduled for day 7, day 28, and 3 months, 6 months, and 12 months after the first injection. Standardized photographs were taken before treatment and during month-3 and month-12 visits. Blood and urine samples were collected and analyzed before injection and at 6 and 12 months after injection. The most common sites of injection were the nasolabial folds (48 percent) and lips (25 percent) followed by glabella folds (8 percent) and other sites. The amount of injected gel ranged from 0.2 to 12 ml. RESULTS: Two hundred twenty-eight patients were followed for 12 months after treatment. In 93 percent, results were judged to be good or very good by the investigators and satisfactory or very satisfactory by the patients. Adverse events that could be ascribed to the treatment were observed in 37 cases, most commonly presenting as transient swelling, hematoma, redness, and pain or itching. In one case, a slight change of skin color at the site of injection was reported. No severe adverse events related to the gel were observed. In one case, neutropenia was detected in month-12 blood samples. The other values were within the normal ranges. CONCLUSIONS: Aquamid is an easy-to-use soft-tissue filler. The effect of tissue enhancement lasted over the entire study period. Transient local tissue reactions observed were attributable to the injection procedure rather than the chemical properties of the gel. During the first year after treatment, no permanent soft-tissue reaction was observed. Long-term results need to be evaluated in the future.

Acrylic Resins↗
PubMed1983

Comparison of polyacrylamide and agarose gel thin-layer isoelectric focusing for the characterization of beta-lactamases.

Plasmid-mediated beta-lactamases from strains of Escherichia coli and Pseudomonas aeruginosa were separated by isoelectric focusing on a 0.8-mm thin-layer agarose gel with a pH gradient of 3.5 to 9.5. Their banding patterns and isoelectric points were compared with those obtained with a 2.0-mm polyacrylamide gel as the support medium. The agarose method produced banding patterns and isoelectric points which corresponded to the polyacrylamide gel data for most samples. Differences were observed for HMS-1 and PSE-1 beta-lactamases. The HMS-1 sample produced two highly resolvable enzyme bands in agarose gels rather than the single faint enzyme band observed on polyacrylamide gels. The PSE-1 sample showed an isoelectric point shift of 0.2 pH unit between polyacrylamide and agarose gel (pI 5.7 and 5.5, respectively). The short focusing time, lack of toxic hazard, and ease of formulation make agarose a practical medium for the characterization of beta-lactamases.

Acrylic Resins↗
PubMed2004

Simplified method for the diameter sizing of serum low-density lipoprotein using polyacrylamide gradient gel electrophoresis.

The appearance of small, dense, low-density lipoprotein in serum has been demonstrated to be associated with increased risk of coronary artery disease. The molecular diameter of low-density lipoprotein is usually measured on the basis of mobility differences on polyacrylamide gel electrophoresis. However, since mobility assessed by this method is seriously affected by the increased levels of serum free fatty acids associated with hypertriglyceridemia, we used polyacrylamide gradient gel electrophoresis to eliminate the interference by fatty acids and devised a simple, precise method of polyacrylamide gradient gel electrophoresis to measure the diameter of small, dense, low-density lipoproteins in serum. We used apoferritin and thyroglobulin, which have a molecular diameter of 12.2 nm and 17.0 nm, respectively, and standard low-density lipoprotein particles having a diameter of 25.7 and 27.0 nm as calibrators, estimated by measurement of negative staining of electron microscopy. We also included apoferritin as an internal standard for polyacrylamide gradient gel electrophoresis. The only stain used was Coomassie brilliant blue, and it was used for lipoprotein staining. When we used low-density lipoprotein of 25.73 nm in diameter as a quality control specimen, the coefficient of variation of the size measurements obtained by our method was less than 1.2%. The new method markedly improved the laboratory procedure for measuring the diameter of low-density lipoproteins.

Apoferritins↗
PubMed2003

[Clinically analyzing the possible side-effects after injecting hydrophilic polyacrylamide gel as a soft-tissue filler].

OBJECTIVE: To evaluate the possible side-effects after injecting hydrophilic polyacrylamide gel for augmentation of the soft-tissue. METHODS: Fifteen patients with some side-effects after injecting the hydrophilic polyacrylamide gel had been undergoing for the treatment in our unit from 2000 to 2001. Their symptoms were analyzed and the specimen of the tissue was also removed for pathologic examination. RESULTS: The major complaints of the patients after injecting hydrophilic polyacrylamide gel were feeling pain(60.00%), uncomfortable (13.33%), no cosmetic improvement results (33.33%), secondary deformity (20.00%), long-lasting swelling (6.67%), and nodules (80.00%). The pathologic examination was showing the capsule formation (53.33%), macrophagocyte infiltration (60.00%) and granuloma producing (20.00%). CONCLUSION: Clinical application of the hydrophilic polyacrylamide gel may result in some serious side-effects. It should be cautious to the physicians who may apply the product for clinic use.

Acrylic Resins↗
PubMed2003

[Analysis and treatment of complications induced by polyacrylamide hydrogel injection].

OBJECTIVE: To explore the reasons for the complications of polyacrylamide hydrogel injection. METHODS: 39 patients were included in this study, who had complications after polyacrylamide hydrogel injection in the breasts, nose, temproal area or depressed locus. The clinical manifestations of the complications were analyzed. RESULTS: Postoperative infection occurred in 5 cases, induration in 23, pain in 25, ulceration of the puncture points in 9, displacement in 6, galactostasis in 1, skin necrosis in 1, breast deformation in 3, bilateral asymmetry in 4, aseptic inflammation in 10, and skin-acne-like changes on the face in 4. CONCLUSION: Some complications were caused mainly by incorrect manipulation and others were relative to the injected material. The applications of polyacrylamide hydrogel as a clinical implant material need further investigations. Polyacrylamide hydrogel injection should be cautiously used.

Acrylic Resins↗
PubMed2005

[The periareolar approach management of postoperative complications of breast augmentation by injected polyacrylamide hydrogel].

OBJECTIVE: To analysis various complications of 30 patients of breast augmentation by injected polyacrylamide hydrogel and discuss the treatment through periareolar incision. METHODS: All patients were classified according to the different complications. Open suction technique and partial mastectomies via periareolar incisions were performed in all patients, Only one patient had immediately breast reconstruction with prosthesis, five patients received secondarily breast prostheses implantation via a axillary incision. RESULT: All the symptoms were relieved after remove of polyacrylamide hydrogel. CONCLUSIONS: Polyacrylamide hydrogel should be prohibited for injected breast augmentation at present. A double-blinded randomized clinical study, controlled animal experiments and a large sample questionnaire survey for complications are necessary. The periareolar approach is valuable technique and can remove polyacrylamide hydrogel as completely as possible.

Acrylic Resins↗
PubMed2006

[Analysis and treatment of the complications post polyacrylamide hydrogel injection for augmentation mammaplasty].

OBJECTIVE: To inquire into the reason why the postoperative complications of augmentation mammaplasty by injecting polyacrylamide hydrogel took place and to find the best method to deal with the complications. METHODS: 12 patients who accepted polyacrylamide hydrogel injection for augmentation mammaplasty were included in this study. Operations were performed to remove the polyacrylamide hydrogel. RESULTS: All patients didn't argue with the result, but the outside shape of mamma was not good post-operation. CONCLUSIONS: So-called standard injection method can't avoid the postoperative complications. The considerable therapy for the complications of polyacrylamide hydrogel was removing it by operation.

Acrylic Resins↗
PubMed1990

Separation of DNA restriction fragments by high performance capillary electrophoresis with low and zero crosslinked polyacrylamide using continuous and pulsed electric fields.

This paper presents results on the separation of DNA restriction fragments by high performance capillary electrophoresis (HPCE). Capillaries containing polyacrylamide with low amounts of crosslinking agent (i.e. 0.5% C) were first studied. The greater molecular accessibility offered with columns of low crosslinking, relative to higher crosslinked gels (e.g. 5% C), permitted high efficiency separations of double stranded DNA fragments up to 12,000 base pairs in length. Capillaries containing no crosslinking agent, i.e. linear polyacrylamide, were then examined. Ferguson plots (i.e. log mobility vs. %T) were used to assess the size selectivity of linear polyacrylamide capillaries. In another study, it was determined that the relative migration of DNA species was a strong function of applied electric field and molecular size. Lower fields yielded better resolution than higher fields for DNA molecules larger than about 1000 base pairs, albeit at the expense of longer separation time. Based on these results, we have examined pulsed field HPCE and have demonstrated the use of this approach to enhance separation.

Acrylic Resins↗
PubMed1994

Brief report: electrophoretic separation of oligonucleotides in replenishable polyacrylamide-filled capillaries.

Linear polyacrylamide at concentrations of 8 to 10% seems to be an excellent matrix for the electrophoretic separation of oligonucleotides and DNA sequencing reactions. However, these solutions, as they are normally prepared, have an enormous viscosity and the polymerization must be done within the capillary. Based on theoretical considerations, we found that linear polyacrylamide of moderate molecular weight and therefore low viscosity could be used instead. We show that the separation of oligonucleotides obtained with such solutions is comparable to those obtained with in situ polymerization of linear or crosslinked polyacrylamide. This method allows easy refilling of the capillaries and might be a step towards automation of oligonucleotide analysis and DNA sequencing.

Acrylic Resins↗
PubMedDate not supplied

Proteome analysis of polyacrylamide gel-separated proteins visualized by reversible negative staining using imidazole-zinc salts.

Identification and characterization of proteins isolated from natural sources by polyacrylamide gel electrophoresis has become a routine technique. However, efficient sample proteolysis and subsequent peptide extraction is still problematic. Here, we present an improved protocol for the rapid detection of polyacrylamide gel-separated proteins, in situ protein modification, proteolytic digestion and peptide extraction for subsequent protein identification and characterization by capillary high-performance liquid chromatography/tandem mass spectrometry. This simple technique employs the rapid imidazole-zinc reverse stain, in-gel S-pyridylethylation and proteolytic digestion of microcrushed polyacrylamide gel pieces with proteases. This technique obviates the need for buffer exchange or gel lyophilisation due to all of the sample manipulation steps being carried out at near neutral pH and thus lends itself readily to automation.

Acrylic Resins↗
PubMed1999

Use of a bilayer stacking gel to improve resolution of lipopolysaccharides and lipooligosaccharides in polyacrylamide gels.

Lipopolysaccharide (LPS) and lipooligosaccharide (LOS) are important antigenic and integral components of the outer membrane of Gram-negative bacteria. Alteration or heterogeneity of LPS/LOS structure is most often assessed by alteration of electrophoretic band profiles using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). In order to discern minor differences in the electrophoretic profile of closely spaced bands, particularly the low molecular weight bands of LOS, optimum resolution is required. Unfortunately, many publications of LPS/LOS in polyacrylamide gels show a diffuse, smeared pattern without discernible bands. We report here a formulation for polyacrylamide gels that reproducibly yields LPS/LOS bands with sharp resolution. A key feature of this formulation is the use of a separate comb gel containing electrode buffer layered on top of the conventional stacking gel.

Acrylic Resins↗
PubMed2001

Quantitative distance information on protein-DNA complexes determined in polyacrylamide gels by fluorescence resonance energy transfer.

In polyacrylamide gels, we have quantitatively determined Forster transfer (fluorescense resonance energy transfer, FRET) between two fluorescent dyes attached to DNA in protein-DNA complexes. The donor-dye fluorescein labeled to DNA retains its free mobility in the polyacrylamide gel, however, its fluorescence properties change. The different quantum yield of fluorescein in the gel is found to be independent of the gel concentration and can thus be quantitatively taken into account by a reduced Forster distance R0 of 46 A compared to 50 A in solution. We have determined global structural properties of two proteins binding to double-labeled DNA using a novel gel-based fluorescence resonance energy transfer assay. In polyacrylamide gels we have analyzed the binding of integration host factor (IHF) and the high mobility group protein NHP6a to their substrate DNA. The measured Forster transfer efficiency allows us to deduce information on the overall shape and the DNA bending angle in the complex.

Acrylic Resins↗
PubMed2000

Conformational isomers of curved DNA molecules can be observed by polyacrylamide gel electrophoresis.

Dimers, trimers and higher multimers of two 147-base pair restriction fragments called 12 A and 12B, obtained from the MspI digest of plasmid pBR322, migrate as sharp bands in agarose and dilute polyacrylamide gels, indicating that they are homogeneous in molecular weight. However, the electrophoretic bands corresponding to multimers of the curved fragment 12A are split into sharp sub-bands in more concentrated polyacrylamide gels. The relative intensities and spacing of the sub-bands depend on the number of monomers in the multimer, the pH of the buffer, and the presence or absence of divalent cations in the solution. Since band splitting is not observed for the normal 12B multimers under any gel-running conditions, the sub-bands observed for multimers of the curved fragment 12A must be attributed to conformational isomers which are in slow exchange on the electrophoretic time scale. Band splitting is also observed for multimers of a curved DNA fragment containing the kinetoplast bending locus and for plasmid pUC19 linearized by digestion with certain restriction enzymes. Plasmid pUC19 contains two nearly equidistant regions of intrinsic curvature (Strutz, K., Stellwagen, N. C., Electrophoresis 1996, 17, 989-995). Hence, DNA molecules containing two or more regions of curvature exist as discrete subpopulations of conformational isomers which can be observed as separate bands migrating in polyacrylamide gels.

DNA↗
PubMed2000

Characterization of the pore structure of aqueous three-dimensional polyacrylamide gels with a novel cross-linker.

The properties of polyacrylamide hydrogels synthesized with a novel hexafunctional (three double bonds) cross-linker, hexahydro-1,3,5-triacryloyl-s-triazine (1a), was evaluated and compared to the currently used tetrafunctional (two double bonds) cross-linker N,N-methylenebisacrylamide (Bis). A variety of characterization techniques that require very little sample preparation and data handling were chosen and include polymerization temperature profiles and conversions, water swelling, differential scanning calorimetry (DSC), polyacrylamide gel electrophoresis (PAGE), Gradiflow electrophoretic separation process and scanning electron microscopy (SEM). The alternative use of 1a compared to Bis results in polyacrylamide gels with larger pore sizes and a broad pore size distribution.

Acrylic Resins↗
PubMed2001

Simultaneous immunoblotting analysis with activity gel electrophoresis in a single polyacrylamide gel.

We describe here that a simple diffusion blotting method can couple immunoblotting analysis with another biochemical technique in a single polyacrylamide gel. The efficiency of protein transfer was evaluated by serial dilutions of nephrosin, a metalloproteinase of the astacin family, and by immunodetection. It is estimated that diffusion blotting produces 25-50% of the signal intensity compared to the classical electrophoretic transfer method. However, with diffusion blotting it is possible to generate several replicas from a single gel. In addition, a protein blot can be obtained from a sodium dodecyl sulfate (SDS)-polyacrylamide gel for zymography assay or from a native polyacrylamide gel for electrophoretic mobility shift assay (EMSA). In this regard, a particular signal in zymography or EMSA can be confirmed by simultaneous immunoblotting analysis with a corresponding antiserum. Therefore, diffusion blotting allows a direct comparison of signals between gels and replicas in zymography assay and EMSA. These advantages make diffusion blotting desirable when partial loss of transfer efficiency can be tolerated or be compensated by a more sensitive immunodetection reaction using enhanced chemiluminescence substrates.

Animals↗
PubMed2002

The separation of oligodeoxynucleotides having a single-base difference by affinity capillary electrophoresis using oligodeoxynucleotide- polyacrylamide conjugate.

We have developed an affinity capillary electrophoresis for gene mutation assay. We show a method for separating a mixture of oligodeoxynucleotides having single-base difference using oligodeoxynucleotide-polyacrylamide conjugate. Because the conjugate behaved similarly to nonionic polyacrylamide in terms of migration rate, it can be used as a pseudoimmobilized affinity ligand in a polyacrylamide-coated capillary. Oligodeoxynucleotide having an oncogene sequence and a version with one base substituted were completely separated by this method. The magnesium-ion concentration was found to be a key factor in achieving efficient separation of oligodeoxynucleotides with the same chain length.

Acrylic Resins↗
PubMed2002

Microdevice-based measurements of diffusion and dispersion in cross-linked and linear polyacrylamide DNA sequencing gels.

We use microfabricated gel electrophoresis devices incorporating integrated on-chip electrodes, heaters, and temperature sensors to measure diffusion and dispersion of single-stranded DNA fragments in cross-linked and uncross-linked polyacrylamide gels. The microdevice format allows a complete set of diffusion and dispersion data to be collected in approximately one hour. These results are compared with corresponding data obtained in a macroscale DNA sequencer, and the effects of gel composition and initiation chemistry are explored. Although the diffusion and dispersion data exhibit similar qualitative trends both on chip and on the macroscale, the magnitudes of the coefficients measured in the microdevice are somewhat higher. This discrepancy is likely due to altered polymerization kinetics arising as a consequence of using a UV-initiated polymerization chemistry to cast the on-chip gels as opposed to the standard chemical polymerization employed on the macroscale. We also find that reductions in the magnitudes of diffusion and dispersion coefficients are achieved at higher polymer concentrations and at operating temperatures in the vicinity of 50 degrees C. Finally, we find that cross-linked polyacrylamide gels yield significantly lower diffusion and dispersion coefficients than linear polyacrylamide. These findings can be used to identify rational strategies to improve separation performance in both micro- and macroscale gel electrophoresis systems.

Cross-Linking Reagents↗