|Articles about Biomaterials|
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| Comparison of effect of vitamin E-coated dialyzer and oral vitamin E on hemodialysis-induced Cu/Zn-superoxide dismutase
Akiyama, S., M. Inagaki, et al. (2005), Am J Nephrol 25(5): 500-6.
Abstract: BACKGROUND: We reported earlier that production of Cu/Zn-superoxide dismutase (SOD) increases markedly in hemodialysis patients but not in non-dialyzed chronic renal failure (CRF) patients. In this study, we compared the antioxidant effects of oral vitamin E supplementation (VE-PO) and vitamin E coating of a dialyzer (VE-BMD) by measuring increased Cu/Zn-SOD in hemodialysis patients. METHODS: 31 hemodialysis patients were divided into two groups: 16 hemodialysis patients underwent usual dialysis with vitamin E supplementation 600 mg/day while 15 others were dialyzed using vitamin E-coated membrane for 6 months. Total plasma SOD activity was determined by NBT method, plasma Cu/Zn-SOD contents by ELISA and Cu/Zn-SOD mRNA in leukocytes by RT-PCR. RESULTS: VE-PO and VE-BMD showed almost comparable effects on Cu/Zn-SOD contents and its mRNA levels in hemodialysis patients. VE-PO resulted in a progressive decrease of Cu/Zn-SOD content (p < 0.001). A comparable progressive decrease was observed also in VE-BMD (p < 0.0001). Both VE-PO and VE-BMD resulted in a progressive decrease of Cu/Zn-SOD mRNA (p < 0.01), which reached the level of non-dialyzed CRF patients.
| Comparison of effectiveness of sirolimus-eluting stents versus bare metal stents for percutaneous coronary intervention in patients at high risk for coronary restenosis or clinical adverse events
Marzocchi, A., G. Piovaccari, et al. (2005), Am J Cardiol 95(12): 1409-14.
Abstract: We evaluated the clinical effect of selective use of sirolimus-eluting stents (SESs) in real-world, high-risk patients. A total of 4,237 consecutive patients who underwent percutaneous coronary intervention (SES, n = 872, bare metal stents [BMSs], n = 3,365) was enrolled in a prospective regional survey. A prespecified high-risk subset of patients was selected on the basis of clinical and angiographic characteristics. A propensity score analysis was performed to compare patients who received SESs with those who received BMSs. Patients in the SES group more often had diabetes and more frequently had previous myocardial infarction or coronary revascularization, type C lesions, and multivessel procedures. Patients who presented with acute myocardial infarction were treated more often with BMSs. At 9 months, the use of SESs was associated with fewer major adverse cardiac events (death, myocardial infarction, or target lesion revascularization; hazard ratio 0.56, 95% confidence interval 0.37 to 0.85) and target lesion revascularizations (hazard ratio 0.43, 95% confidence interval 0.20 to 0.91). This decrease was more evident in a prespecified high-risk subgroup of patients (major adverse cardiac events, 8.0% SES vs 15.6% BMS, hazard ratio 0.45, 95% confidence interval 0.29 to 0.72). We conclude that selective SES use in real-world patients who have high-risk clinical and angiographic characteristics is associated with significant decreases in major adverse cardiac events and repeat revascularizations compared with BMS use.
| Comparison of haemocompatibility improvement of four polymeric biomaterials by two heparinization techniques
Michanetzis, G. P., N. Katsala, et al. (2003), Biomaterials 24(4): 677-88.
Abstract: Two surface heparinization procedures, introduced by Bamford and Al-Lamee (Polymer 22 (1996) 4885; 13 (1994) 2844) and Seifert et al. (J. Mater. Sci.: Mater. Med. 7 (1996) 465), respectively, were applied to four commercially available biomaterials (silicone rubber, polyethylene, polypropylene and polyvinylchloride) in order to compare their efficiency in improving haemocompatibility. The indirect method (Bamford and Al-Lamee) produced a much better heparinization yield-10.5% maximum, compared to the direct one (Seifert et al.), of only 0.20% maximum. Both methods provided a better response of the heparinized biomaterials compared to the uncoated ones in terms of platelet retention and a significantly better response in terms of activation of the coagulation system, suggesting that heparin molecules remained biologically functional in both cases. The results were particularly interesting in the case of polyvinylchloride where the maximum immobilization yield was obtained by the indirect method resulting also to a pronounced haemocompatibility improvement. Scanning electron microscopy studies confirmed adhered platelet morphology whereas atomic force microscopy was used to examine surface morphology of heparinized and reference materials surface.
| Comparison of human mandibular osteoblasts grown on two commercially available titanium implant surfaces
Galli, C., S. Guizzardi, et al. (2005), J Periodontol 76(3): 364-72.
Abstract: BACKGROUND: Surface characteristics play a major role in determining tissue response to implants and therefore their clinical outcome. The aim of the present study was to compare two commercially available titanium surfaces: plasma sprayed (TPS) and sand-blasted, acid-etched surface (SLA). METHODS: The surfaces were characterized by roughness testing, scanning electronic microscopy (SEM), Raman spectroscopy, and protein adsorption to determine their microtopographic and chemical properties. The effect of the surfaces on human mandibular osteoblasts was then studied in terms of cell morphology, adhesion, proliferation, and differentiation. Human osteoblasts from the mandible were cultured on these two surfaces and evaluated at 3, 6, 24, and 48 hours to determine cell attachment and morphology. Growth and differentiation kinetics were subsequently investigated by evaluating cell growth, alkaline phosphatase activity, osteocalcin and osteoprotegerin production at 7, 14, and 21 days. RESULTS: Although roughness was quite similar, the two surfaces presented strong differences in their topography, and cell morphology varied as a consequence. Osteoblasts on SLA appeared more elongated and spindle shaped than those on TPS, and their adhesion at 3 and 6 hours was weaker, but reached that of cells on TPS at hour 24. Cell proliferation was greater on SLA surfaces but differentiation parameters; i.e., alkaline phosphatase and osteocalcin, provided better results on TPS surfaces. Osteoprotegerin production was enhanced on TPS surfaces at days 14 and 21. CONCLUSION: Although cells grown on both surfaces exhibited good adhesion capabilities, a well-differentiated osteoblastic phenotype, and maintained a clear proliferation potential, our study suggests that plasma-sprayed treatment offers a better performance than SLA by creating, at least in the early phases, better conditions for tissue healing.
| Comparison of human, primate, and canine femora: implications for biomaterials testing in total hip replacement
Kuo, T. Y., J. G. Skedros, et al. (1998), J Biomed Mater Res 40(3): 475-89.
Abstract: The canine model remains an animal of choice for determining the efficacy and safety of various materials and designs used in human total hip replacement (THR). The primate also is used in orthopedic-related research for studying limb anatomy, gait, and age-related bone loss. In order to better understand the appropriateness of these animal models for human THR, external morphologies of thirty-three adult Caucasian human, sixteen adult chimpanzee, and forty-two adult greyhound femora were compared using osteometric methods. Measured parameters included anteversion angle, cervico-diaphyseal angle, femoral head offset in the frontal plane, and anterior bow profiles along the femoral diaphysis. Although some of the measured parameters were approximately similar between species (e.g., mean cervico-diaphyseal angle of humans and chimpanzees), the majority demonstrated morphologic differences that may be biomechanically significant for interpreting stress transfer across the hip (e.g., mean anteversion angle and mean normalized femoral head offset between species). Additionally, age-related changes in proximal femoral morphology and gait pattern, as well as species-related differences in local muscle and inertial forces, may result in notably different loading conditions across the hip joint of each species. Therefore, discretion must be exercised when evaluating canine or primate THR materials and designs for potential use in the human hip.
| Comparison of implantation and cytotoxicity testing for initially toxic biomaterials
Rosengren, A., L. Faxius, et al. (2005), J Biomed Mater Res A 75(1): 115-22.
Abstract: To evaluate the predictive value of cytotoxicity testing, the present study compares the in vivo tissue responses to in vitro cytotoxicity before and after implantation. Material toxicity was caused by addition of the toxic substance Zincdiethyldithiocarbamate (ZDEC) that is used as a standard for in vitro cytotoxicity testing. Polyurethane discs with the addition of 0.5% or 1% ZDEC as well as nontoxic discs were inserted in the abdominal wall of rats for 1 day up to 6 weeks. After explantation the foreign body response was analyzed immunohistochemically. An in vitro reanalysis of the explanted reference materials (RMs) revealed remaining high concentrations of toxic compounds after 1-week implantation, whereas no toxicity was seen after 6 weeks implantation. This was reflected in the foreign body response where a significantly thicker capsule and more inflammatory cells were seen at 1 week for the toxic implants. Over time, with decreasing toxicity, these differences disappeared. Test samples that only were subjected to in vitro extraction with water did not elute toxic compounds to the same extent as the in vivo conditions. It is concluded that many clinically useful implant materials may be unnecessarily rejected due to the results of in vitro tests.
| Comparison of in vitro bacterial bioluminescence and tissue culture bioassays and in vivo tests for evaluating acute toxicity of biomaterials
Burton, S. A., R. V. Petersen, et al. (1986), J Biomed Mater Res 20(6): 827-38.
Abstract: The sensitivity of a bacterial bioluminescent acute toxicity test was compared to the sensitivity of the USP mouse safety, rabbit intramuscular implantation, rabbit intracutaneous, mouse systemic injection, and the MEM elution tissue culture tests. A variety of industrial plastics were used to evaluate the comparative sensitivities. Additional tests were conducted on low-density polyethylene containing a range of dibutyltin dichloride or trans-cinnamic acid concentrations. The bacterial bioluminescent test was more sensitive than any of the in vivo acute toxicity tests. The luminescent bacterial test was generally more sensitive than the tissue culture acute toxicity assay. The bacterial bioluminescent test offers a sensitive, rapid, uncomplicated, and inexpensive means for preliminary compatibility evaluation of biomaterials.
| Comparison of metal release from various metallic biomaterials in vitro
Okazaki, Y. and E. Gotoh (2005), Biomaterials 26(1): 11-21.
Abstract: To investigate the metal release of each base and alloying elements in vitro, SUS316L stainless steel, Co-Cr-Mo casting alloy, commercially pure Ti grade 2, and Ti-6Al-4V, V-free Ti-6Al-7Nb and Ti-15Zr-4Nb-4Ta alloys were immersed in various solutions, namely, alpha-medium, PBS(-), calf serum, 0.9% NaCl, artificial saliva, 1.2 mass% L-cysteine, 1 mass% lactic acid and 0.01 mass% HCl for 7d. The difference in the quantity of Co released from the Co-Cr-Mo casting alloy was relatively small in all the solutions. The quantities of Ti released into alpha-medium, PBS(-), calf serum, 0.9% NaCl and artificial saliva were much lower than those released into 1.2% L-cysteine, 1% lactic acid and 0.01% HCl. The quantity of Fe released from SUS316L stainless steel decreased linearly with increasing pH. On the other hand, the quantity of Ti released from Ti materials increased with decreasing pH, and it markedly attenuated at pHs of approximately 4 and higher. The quantity of Ni released from stainless steel gradually decreased with increasing pH. The quantities of Al released from the Ti-6Al-4V and Ti-6Al-7Nb alloys gradually decreased with increasing pH. A small V release was observed in calf serum, PBS(-), artificial saliva, 1% lactic acid, 1.2% l-cysteine and 0.01% HCl. The quantity of Ti released from the Ti-15Zr-4Nb-4Ta alloy was smaller than those released from the Ti-6Al-4V and Ti-6Al-7Nb alloys in all the solutions. In particular, it was approximately 30% or smaller in 1% lactic acid, 1.2% L-cysteine and 0.01% HCl. The quantity of (Zr + Nb + Ta) released was also considerably lower than that of (Al + Nb) or (Al + V) released. Therefore, the Ti-15Zr-4Nb-4Ta alloy with its low metal release in vitro is considered advantageous for long-term implants.
| Comparison of microstructural evolution in Ti-Mo-Zr-Fe and Ti-15Mo biocompatible alloys
Nag, S., R. Banerjee, et al. (2005), J Mater Sci Mater Med 16(7): 679-85.
Abstract: The microstructural evolution and attendant strengthening mechanisms in two biocompatible alloy systems, the binary Ti-15Mo and the quaternary Ti-13Mo-7Zr-3Fe (TMZF), have been compared and contrasted in this paper. In the homogenized condition, while the Ti-15Mo alloy exhibited a single phase microstructure consisting of large beta grains, the TMZF alloy exhibited a microstructure consisting primarily of a beta matrix with grain boundary alpha precipitates and a low volume fraction of intra-granular alpha precipitates. On ageing the homogenized alloys at 600 degrees C for 4 h, both alloys exhibited the precipitation of refined scale secondary alpha precipitates homogeneously in the beta matrix. However, while the hardness of the TMZF alloy marginally increased, that of the Ti-15Mo alloy decreased substantially as a result of the ageing treatment. In order to understand this difference in the mechanical properties after ageing, TEM studies have been carried out on both alloys in the homogenized and homogenized plus aged conditions. The results indicate that the omega precipitates dissolve on ageing in case of the Ti-15Mo alloy, consequently leading to a substantial decrease in the hardness. In contrast, the omega precipitates do not dissolve on ageing in the TMZF alloy and the precipitation of the fine scale secondary alpha leads to increased hardness.
| Comparison of posterior capsule opacification rates between hydrophilic and hydrophobic single-piece acrylic intraocular lenses
Heatley, C. J., D. J. Spalton, et al. (2005), J Cataract Refract Surg 31(4): 718-24.
Abstract: PURPOSE: To determine the effect of intraocular lens (IOL) material on the development of posterior capsule opacification (PCO) at 1 year. SETTING: Department of Ophthalmology, St. Thomas' Hospital, London, United Kingdom. METHODS: One hundred six eyes of 53 patients with bilateral cataract and no other ocular comorbidity were prospectively randomized to receive a hydrophobic acrylic or hydrophilic acrylic single-piece IOL in the first eye to have surgery. The alternate IOL was implanted in the fellow eye 4 to 6 weeks later. All surgery was performed by a single surgeon. Postoperative follow-up was 1 day, 1 and 6 months, and 1 year. At each visit, the best corrected high- and low-contrast visual acuities were assessed and a high-intensity digital retroillumination photograph was taken. Posterior capsule opacification was assessed from the digital images by a single operator using a dedicated software program and calculated as the percentage area of opacified capsule. RESULTS: One year postoperatively, the median percentage area of PCO was 50.3% in the hydrophilic IOL group and 4.9% in the hydrophobic IOL group (P<.001). The difference in PCO was not accounted for by loss of contact between the capsulorhexis and IOL surface. Further analysis showed that lens epithelial cells tended to invade the posterior capsule at the haptic-optic junction. This was more marked in the hydrophilic IOL group. CONCLUSIONS: The rate of PCO was significantly higher with the hydrophilic IOL. However, the results cannot be attributed to the IOL material alone as they show the importance of both IOL material and design.
| Comparison of prosthetic materials in incisional hernia repair
Demir, U., M. Mihmanli, et al. (2005), Surg Today 35(3): 223-7.
Abstract: PURPOSE: Incisional hernias are not uncommon after abdominal surgery, but their repair is associated with a high risk of complications, including adhesions and recurrence. Many different types of meshes and adhesion barriers have been developed in an attempt to overcome these problems, some of which we have assessed in a rat model. METHODS: We made a full-thickness 1.5 x 2.5-cm abdominal wall defect in 30 Sprague-Dawley rats, which were divided into three groups according to the materials used for repair: 2 x 3-cm polypropylene mesh (group 1); expanded polytetrafluoroethylene (PTFE) with double-layer polypropylene mesh (group 2); or polypropylene mesh with oxidized cellulose adhesion barriers (group 3). We assessed adhesion formation, tensile strength, and histopathologic findings. RESULTS: The mean adhesion scores were 3.3, 1.3, and 0.7, in groups 1, 2, and 3, respectively (P < 0.001). The area involved by adhesions was significantly greater in group 1 than in groups 2 or 3 (P < 0.01, P < 0.05), but there was no significant difference between groups 2 and 3 (P < 0.05). The tensile strength in group 2 was less than that in groups 1 or 3 (P < 0.01, P < 0.05), but there was no significant difference between groups 1 and 3 (P > 0.05). CONCLUSION: Although there was less adhesion formation with PTFE and oxidized cellulose, PTFE not only impaired the tensile strength, but also induced fibrosis and inflammation. An oxidized cellulose adhesion barrier can be safely used in incisional hernia repair to prevent intra-abdominal adhesions.
| Comparison of scaffolds and culture conditions for tissue engineering of the knee meniscus
Aufderheide, A. C. and K. A. Athanasiou (2005), Tissue Eng 11(7-8): 1095-104.
Abstract: The menisci of the knee are semilunar fibrocartilaginous structures critical in load bearing, shock absorption, stability, and lubrication. In this study, two commonly used biomaterials, a hydrogel (agarose) and a nonwoven mesh polymer [poly(glycolic acid); PGA], were compared for suitability as scaffold materials for tissue engineering the knee meniscus. In addition, a rotating wall bioreactor culture of both scaffold materials was compared with static cultures. Constructs were cultured for up to 7 weeks in static and rotating wall bioreactor culture. Cell numbers were 22 times higher in PGA than agarose after 7 weeks in culture. Static PGA scaffolds had more than twice the amount of sulfated glycosaminoglycans and three times the amount of collagen compared to static agarose constructs at week 7. The rotating wall bioreactor was not found with increase matrix production or cell proliferation significantly over static cultures.
| Comparison of small-intestinal submucosa and expanded polytetrafluoroethylene as a vascular conduit in the presence of gram-positive contamination
Shell, D. H. t., M. A. Croce, et al. (2005), Ann Surg 241(6): 995-1001; discussion 1001-4.
Abstract: OBJECTIVE: As a vascular conduit, expanded polytetrafluoroethylene (ePTFE) is susceptible to graft infection with Gram-positive organisms. Biomaterials, such as porcine small-intestinal submucosa (SIS), have been successfully used clinically as tissue substitutes outside the vascular arena. SUMMARY BACKGROUND DATA: In the present study, we compared a small-diameter conduit of SIS to ePTFE in the presence of Gram-positive contamination to evaluate infection resistance, incorporation and remodeling, morphometry, graft patency, and neointimal hyperplasia (NH) development. METHODS: Adult male mongrel pigs were randomized to receive either SIS or ePTFE (3-cm length, 6-mm diameter) and further randomized to 1 of 3 groups: Control (no graft inoculation), Staphylococcus aureus, or mucin-producing S epidermidis (each graft inoculation with 10 colonies/mL). Pressure measurements were obtained proximal and distal to the graft to create the iliac/aorta pressure ratio. Morphometric analysis of the neointima and histopathologic examinations was performed. Other outcomes included weekly WBC counts, graft incorporation, and quantitative culture of explanted grafts. RESULTS: Eighteen animals were randomized. All grafts were patent throughout the 6-week study period. Infected SIS grafts had less NH and little change in their iliac/aorta indices compared with infected ePTFE grafts. Quantitative cultures at euthanasia demonstrated no growth in either SIS group compared with 1.7 x 10(4) colonies for ePTFE S aureus and 6 x 10(2) for ePTFE S epi (each P < 0.001). All SIS grafts were incorporated. Histology demonstrated remodeling into host artery with smooth muscle and capillary ingrowth in all SIS groups. Scanning electron micrography illustrated smooth and complete endothelialization of all SIS grafts. CONCLUSIONS: Compared with ePTFE, SIS induces host tissue remodeling, exhibits a decreased neointimal response to infection, and is resistant to bacterial colonization. SIS may provide a superior alternative to ePTFE as a vascular conduit for peripheral vascular surgery.
| Comparison of tethered star and linear poly(ethylene oxide) for control of biomaterials surface properties
Irvine, D. J., A. M. Mayes, et al. (1998), J Biomed Mater Res 40(3): 498-509.
Abstract: Four different poly(ethylene oxide) [PEO] molecules were compared as grafted polymer layers for biomaterials' substrates: two linear polymers and two star polymers. Conditions maximizing surface coverage for each molecule were employed with the aim of inhibiting protein adsorption and increasing the density of end groups. Neutron reflectivities of the grafted layers immersed in deuterium oxide (heavy water) were measured and used to calculate volume fraction profiles of the polymer as a function of distance from the surface. These density profiles were combined with protein adsorption data on the grafted layers to compare with recent theoretical and experimental studies of protein resistance by PEO at surfaces. We found that the grafting density is maximized by coupling the linear PEO from a K2SO4 salt buffer, which is a poor solvent for PEO. However, the grafting density of star PEO was maximized when no K2SO4 was used and the stars were dissolved near the overlap concentration. Concentration profiles obtained from the reflectivity data show that the hydrated polymers swell to approximately 10 times the dried layer thickness and exhibit a low density (maximum volume fractions < 0.4 PEO) throughout the layer. The PEO surfaces obtained with both the star and linear polymers resisted adsorption of cytochrome-c and albumin except for a small amount of cytochrome-c adsorption on the short, many-armed star polymer surface. A hypothesis of adsorption on the star polymer layer is presented and criteria for controlling receptor-mediated cell-substrate interactions by ligand-modified chain ends are discussed.
| Comparison of tetrazolium colorimetric and 51Cr release assays for cytotoxicity determination of dental biomaterials
Bean, T. A., W. C. Zhuang, et al. (1995), Dent Mater 11(5): 327-31.
Abstract: OBJECTIVES: The purpose of this study was to compare a methylthiazole tetrazolium (MTT) dye colorimetric method with the standard 51Cr assay as methods of assessing cytotoxicity of dental materials. METHODS: Two MTT-based colorimetric formats, test tube and 96-well microplate methods, were compared to the 51Cr release assay. A series of eight dental materials were evaluated. Cytotoxicity profiles were determined for each test material. A TC50 value (Toxic Concentration required to kill 50% of the cells) was determined for each biomaterial, and these results were used to make statistical comparisons between the methods. RESULTS: The three methods were statistically correlated (p<0.005) by comparison of the eight samples tested. That is, the same rank in toxicity was given by the two tetrazolium sample formats and the 51Cr method. SIGNIFICANCE: The MTT assay was found to have several advantages in comparison to the current standard 51Cr release assay. Optimized in the 96-well format, complete dose response curves and greater sample comparisons can be made rapidly, making the MTT method more economical in time and cost. Furthermore, the MTT method is based on intracellular biochemical changes, measuring cell viability rather than cell morbidity, and has lower detectable limits than the 51Cr release method. There is also less detector chemical binding interference than encountered in the 51Cr release method.
| Comparison of the life-time of P25 and A11 TiO2 in a labyrinth flow photoreactor
Grzechulska-Damszel, J. and A. W. Morawski (2005), Environ Technol 26(5): 515-24.
Abstract: A series of experiments for the comparison of activity and life-time of anatase titanium dioxide, Tytanpol All (Chemical Factory "Police", Poland) with Degussa P25 (Germany) was conducted in a labyrinth flow reactor with an immobilized catalyst bed. Phenol, with relatively high concentration up to 100 mg dm(-3), was chosen as a model organic compound. Photocatalytic materials were characterized by determination of: phenol decomposition degree, reaction rate constant, band gap energy, FTIR spectra and phase composition. The pureanatase Tytanpol All shows comparable activity as Degussa P25. However, the life-time of P25 Degussa at high phenol concentration was lower compared to that of anatase A11 because of the carbon deposit formation on P25 surface. The catalytic activity of rutile phase in P25 in the reaction of carbon deposits formation is postulated.
| Comparison of the mucoadhesive properties of various polymers
Grabovac, V., D. Guggi, et al. (2005), Adv Drug Deliv Rev 57(11): 1713-23.
Abstract: In this study the mucoadhesive potential of nineteen different, most often referred mucoadhesive polymers was evaluated and characterized by adhesion time and total work of adhesion (TWA) of the polymer to porcine small intestinal mucosa. In addition, the influence of pH of the polymer and of method of drying on adhesion was evaluated. Aqueous polymer solutions were therefore adjusted to pH 3.0 and 7.0. Solutions were either dried by lyophilization (lyo.) or precipitated (pr.) in organic solvent and air-dried. Results of this study led to the following rank order of adhesion time: chitosan-4-thiobuthylamidine pH 3 lyo. >chitosan-4-thiobuthylamidine pH 6.5 pr.>polycarbophil-cysteine pH 3 lyo.>chitosan-4-thiobuthylamidine pH 6.5 lyo.>PAA450-cysteine pH 3 lyo.>pH 7 pr.>Carbopol 980 pH 7 pr.>Carbopol 974P pH 7 pr.>polycarbophil pH 7 pr.>980 pH 3 lyo. The rank order obtained for adhesion time was in agreement with the rank order obtained for total work of adhesion. The highest mucoadhesion was shown by thiolated polymers at pH 3.0, dried by lyophilization. In contrary, polyacrylates were most mucoadhesive in form of precipitated neutral sodium salts. Other tested polymers like natural polysaccharides, cellulose derivatives, polyvinylpirrolidone and polyethylenglycole, although previously reported as good mucoadhesives, showed low to almost no mucoadhesion. The pH of polymer and drying method were found to be important factors influencing the mucoadhesive potential of polymers.
| Comparison of two absorbable monofilament polydioxanone threads in intradermal buried sutures
Coras, B., U. Hohenleutner, et al. (2005), Dermatol Surg 31(3): 331-3; discussion 333.
Abstract: BACKGROUND AND OBJECTIVES: Two absorbable polydioxanone threads are compared regarding intraoperative handling qualities, scar dehiscence, and possible side effects. METHODS: In 30 excisions, half of each suture was performed with PDS II (Ethicon GmbH, Norderstedt, Germany), whereas the other half was closed with Serasynth (Serag-Wiessner, Naila, Germany). Clinical evaluation for scar spreading, spitting of the sutures, hypertrophic scarring, or suture granuloma was performed 3 and 6 months after surgery. RESULTS: No significant difference in scar spreading, hypertrophic scarring, or the incidence of suture granuloma was noted. A significantly lower frequency of spitting was seen with Serasynth than with PDS. The handling and suturing properties of SerasynthM were estimated to be slightly superior compared with those of PDS. CONCLUSION: Our study shows that PDS and Serasynth provide equal cosmetic results when applied in an appropriate suturing technique. Possibly owing to its better pliability, the frequency of spitting was lower with Serasynth.
| Compatibility of biomaterials
Laing, P. G. (1973), Orthop Clin North Am 4(2): 249-73.
| Compatibility of biomaterials with blood
Huang, L. R. and C. R. Zobel (1991), Biomater Artif Cells Immobilization Biotechnol 19(3): 663-6.
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