Biomaterials.info - Resources for Engineers

Record 121 to 140

[Compounding techniques of bioactive ceramic and polymer biomaterials]
Fu, T., D. Yu, et al. (2002), Sheng Wu Yi Xue Gong Cheng Xue Za Zhi 19(1): 108-11.
Abstract: Some techniques of compounding bioactive ceramics and polymer biomaterials with mechanical and biological properties and the clinical applications of the composites produced are presented.

[Contouring of a rigid eyelid implant: indication for the replacement with the platinum chain]
Schrom, T., M. Holzl, et al. (2005), Laryngorhinootologie 84(7): 493-6.
Abstract: BACKGROUND: The resultant lagophthalmos at peripheral facial palsy can lead to keratopathy of varying degrees. In surgical therapy of lagophthalmos some implants to preserve a sufficient eyelid closure have been described. Besides to the use of magnets, silicone slings or palpebral springs the importance of the gold implantation (lidloading), first described by Illig in 1958, has increased. Unfortunately all of these techniques have often shown unwanted side effects. The platinum chain is a new implant which promises, due to its flexibility, lower postoperative complications. PATIENTS: We present two case reports to show the platinum chain's advantages compared to the older implants. The two patients developed a unsightly contouring (with threatening extrusion) of the rigid gold implant after lidloading. These gold implants were therefore replaced in one step by the platinum chain. RESULTS AND CONCLUSIONS: The further process was complication-free. In our opinion, in spite of the small case number, the new developed platinum chain can lead to a reduction of postoperative complications after lidloading. In complications with the rigid gold implants, such as contouring or extrusion, these implants can mostly be replaced in one step by corresponding platinum chains.

[Coronal filling biomaterials. Criteria for selection]
Degrange, M. (1990), Real Clin 1(1): 9-26.
Abstract: The aim of this paper is to assess filling biomaterials according to specification criteria, the foremost of which is the respective ability of each to form a tight seal along cavity walls. Their direct or indirect (cementing or bonding) adhesive potential is the determining factor in their durability and the biocompatibility of the restoration achieved. Gold inlay alloys and amalgams appear as yet to be the most reliable and well-tolerated biomaterials for posterior restorations. For filling small cavities in the anterior sector, microfilled composites are clearly indicated; bonded porcelain, while not yet validated over time, would seem to be a good alternative for more extensive restorations.

[Correction of facial lipoatrophy with a biodegradable material in HIV-infected patients]
Carbonnel, E. and A. Claudy (2005), Ann Dermatol Venereol 132(6-7 Pt 1): 521-4.
Abstract: INTRODUCTION: Facial lipoatrophy in HIV-infected patients under tri-therapy occurs frequently and alters their quality of life. No systemic treatment is capable of curing this problem. PATIENTS AND METHODS: Eighty-one patients were included in an open, prospective, compassionate study. A strict intradermal injection of a biodegradable, polyacrylamide cationic copolymer was administered in several sessions. RESULTS: In all the patients, the correction of the facial lipoatrophy was considered satisfactory and stable over a period of 6 months using comparative photographic cliches. The thickness of the dermal skin, assessed by sonography, was doubled. No local or systemic side effect was reported. CONCLUSION: Our study shows that is it possible to durably correct the facial lipoatrophy of HIV-infected patients under tri-therapy by using a biodegradable implant.

[Cosmetic results of posttraumatic eyeball subatrophy surgical treatment using "alloplant" biomaterials with subsequent use of prostheses]
Galimova, L. F., E. R. Muldashev, et al. (2000), Vestn Oftalmol 116(6): 28-31.
Abstract: A complex of surgical operations making use of Alloplant biomaterials, performed in 47 patients with initial posttraumatic subatrophy and 79 patients with well-developed and far advanced stages of this condition, helped preserve the eye as anatomical organ in 97.5% patients, with enlargement of the eyeball in two-thirds of patients and stabilization in one-third. Optic reconstructive operations were later performed and visual acuity improved in patients with the initial stage of subatrophy. Use of allotransplant for eyeball bandage in order to create a carcass for the sclera helped conceal the cicatricial deformation of the sclera and repair the shape and volume of the eyeball in patients with initial subatrophy, due to which a good cosmetic result was attained. In well-developed and far advanced subatrophy use of biomaterial for bandage created optimal conditions for thin-wall cosmetic prostheses, ruled out the irritating effect of the prosthesis in cases when corneal sensitivity was retained and/or there were coarse corneaoscleral cicatrices, and thus extended the indications for cosmetic prostheses of subatrophic eyes.

[Cultivation of human cells on polymer covered biomaterial--a new concept to improve the implant characteristics. Results of an in-vitro-investigation]
Pierkes, M., B. J. Chang, et al. (2004), Herz 29(3): 341-7.
Abstract: BACKGROUND AND PURPOSE: Calcific degeneration with the resulting need for operative replacement remains the major drawback of bioprostheses. Previous studies have shown that cellular surface seeding decreases calcium uptake in vitro and in vivo, but complete coverage remains difficult to achieve. A new approach is presented, masking glutaraldehyde residues with a covalently bound polymer layer thus facilitating cell seeding. The aim of this study was to evaluate different polymers for their ability to promote surface cell adhesion and formation of complete monolayers. MATERIAL AND METHODS: Ten ultrathin polymers, covalently bound to glass and exhibiting different physicochemical characteristics (thickness, molecular weight, hydrophilic properties, electrical charge) were seeded with human endothelial cells. Four of the ten polymers were also seeded with fibroblasts. As a reference, both cell types were seeded on glass surface. Quality of cell growth and coverage was evaluated by light and scanning electron microscopy. RESULTS: Five of ten polymers and glass exhibited excellent growth and complete surface coverage after 2 weeks, two allowed less cell adherence than glass reference, and three showed only poor cellular growth without adherence. Scanning electron microscopy demonstrated an intact monolayer for the five polymers with excellent cell coverage. Fibroblasts grew well on glass but not on the four tested polymers. No correlation was found between molecular weight, thickness, hydrophilic or charge characteristics of the polymers. CONCLUSION: Several ultrathin polymers, seeded with human endothelial cells, permit complete monolayer formation, but without any apparent correlation to physicochemical characteristics. Polymers covalently bound to biologic tissue appear as a promising approach to prevent calcific degeneration of bioprostheses.

[Current problems and future trends of polymeric biomaterials for orthopaedic surgery]
Ikada, Y. (1996), Nippon Seikeigeka Gakkai Zasshi 70(1): 28-39.

[Current researches of degradation mechanism of bone reconstruction biomaterials containing calcium]
Zhu, J. and H. L. Deng (2002), Shanghai Kou Qiang Yi Xue 11(4): 363-5.

[Current status and trends in biomaterials (author's transl)]
Matsumoto, H. and Y. Sakurai (1979), Iyodenshi To Seitai Kogaku 17(2): 103-11.

[Dental science and biomaterials]
Nakamura, M., Y. Kawata, et al. (1983), Shikai Tenbo 62(6): 1117-24.

[Dento-stomato-facial rehabilitation of young patients. Practical alternatives]
Tatarciuc, M., I. Gradinaru, et al. (2004), Rev Med Chir Soc Med Nat Iasi 108(3): 690-5.
Abstract: The design conception and the technological achievement of every gnato-prosthetic device are conditioned by a minute evaluation of the biological and morphological individualities of each case, the social level of the patient, corroborated with the technological supply. In our study we evaluated different modalities of dento-stomato-facial rehabilitation of young patients with partially reduced maxillary or mandibular dentition. The study was carried out on a group of 12 young patients, 5 males and 7 females, aged between 16-24 years, who presented at the clinic for the treatment of complex functional disorders that occurred as a consequence of the dentition. The fixed mixed gnatoprosthetic therapy for the young patients and teenagers has to be adapted to the surveyed clinical individuality. The success of the therapy is assured by the accurate application of the gnatoprosthetic principles, the accurate achievement of the technological steps, the use of compatible biomaterials according to the dento-stomato-facial features of this age category.

[Detection of bacterial biofilm on medical biomaterials]
Rozalska, B., B. Sadowska, et al. (1998), Med Dosw Mikrobiol 50(1-2): 115-22.
Abstract: This study was performed to assess the value TTC assay in the diagnosis of biomaterial-associated infections. In this assay, soluble colourless TTC is reduced to insoluble red formazan by electron transfer associated with active oxidative bacterial metabolism and is precipitated intracellularly. Microbial adhesion and biofilm formation on the surface of medical prosthetic devices (vesicular and urinary catheters) made of various polymers (PTFE, H-PE, PCW, SL), were determined. The microorganisms which are most often isolated in medical device-associated infections: S. aureus, S. epidermidis, E. faecalis, E. coli, P. vulgaris, P. aeruginosa, C. albicans, were included into the study. The obtained results indicate that the assay using TTC as a metabolic indicator of bacterial biofilm presence, is technically simple to conduct with minimal setup time. Even when classical cultures yielded no bacterial growth, TTC assessments demonstrated bacterial biofilms. TTC assay could be recommended as a quick routine method for confirmation of biomaterial device-associated infection.

[Detection of furadan in biological fluids]
Shormanov, B. K., E. A. Kovalenko, et al. (2005), Sud Med Ekspert 48(5): 36-9.
Abstract: Optimal conditions have been determined for furadan isolation from biological fluids by means of the mixture of solvents ethyl acetate-acetone in volume 1:1. Possible purification of the compound from coextractive substances of biomaterial on the column with silica gel L 100/160 mcm is demonstrated. IR-spectrophotometric methods and high performace liquid chromatography with a detector of photodiode matrix are proposed for identification and quantitation of furadan in blood and urine specimens.

[Detection of pentachlorophenol in biomaterial using HPLC]
Liao, L. C., Y. Y. Yan, et al. (2004), Sichuan Da Xue Xue Bao Yi Xue Ban 35(3): 427-8.
Abstract: OBJECTIVE: To develop a method of detecting pentachlorophenol in biomaterial. METHODS: The samples were extracted by ether, and the characters of the high performance liquid chromatography (HPLC) method were studied. RESULTS: A method for the detection of pentachlorophenol in fish tissue samples was set up with the conditions of chromatography as follows: the compounds are separated on Hypersil ODS column(4.6 mm i.d. x 150 mm, 5 microns) and eluted with methanol which contains 2 g/L NH4Ac (20:80) using 305 nm as the detecting wavelength, the recovery of method being 76%, the linear range 0.042 microgram/g-1.344 micrograms/g, and the correlation coefficient 0.9994, the limit of quantification 0.014 microgram/g. Finally, pentachlorophenol was successfully detected in the fish tissue samples. CONCLUSION: The method has been proven useful in the forensic cases involved in the poisoning of pentachlorophenol.

[Detection of Pseudomonas aeruginosa biofilm on medical biomaterials]
Wolska, K. and A. Jakubczak (2003), Med Dosw Mikrobiol 55(4): 371-8.
Abstract: The adhesion and biofilm formation of Pseudomonas aeruginosa strains on the surface of catheters made of various polymers (PU, SL, PCW) were determined in vitro. It was used the method by Richards et al. with modification of Rozalska et al. (1998), in which soluble colourless TTC is reduced to insoluble red formazan. The results of this study indicate that 80.3% of this strains adhered and 94.6% formed biofilm on the Nelaton catheter, 86% strains adhered and 76.1% formed biofilm on the polyurethane catheter, and 73.2% strains adhered, and 78.9% formed biofilm on the Foley catheter.

[Determination of heterocyclic inhibitors of nitrification in environmental objects and biomaterials]
Buniatian Iu, A. (2001), Gig Sanit(1): 74-6.

[Development of a freezing drier for lyophilization of biomaterials]
Wu, Z., M. Gen, et al. (2004), Sheng Wu Yi Xue Gong Cheng Xue Za Zhi 21(3): 460-3.
Abstract: To observe and assess the performance and effect of our self-made FD-1 freezing drier on biomaterials. R502 compressor and R502 refrigerating agent were adopted. In the experiment, FD-1 lyophilized collagen sponge, strain and defibrinogenase. The evaporating-condenser temperature reached -45 degrees C and the small icebox temperature reached -30 degrees C under the loading or free-loading circumstances in the lyophilizing box. The lyophilized collagen sponge had many pores in the structure, and the strain and the defibrinogenase were lyophilized and maintained satisfactorily. This freezing drier is suitable for lyophilizing some biomaterial samples in small or medium batches.

[Development of slow releasing anticancer drug based with absorbable biomaterial chitin]
Suzuki, K., T. Nakamura, et al. (1991), Gan To Kagaku Ryoho 18(11): 1833-6.
Abstract: To have a comparatively more slowly releasing anticancer drug with effectiveness, Plachitin was prepared by chemical combination of CDDP and chitin (poly-N-acetyl-D-glucosamine). Chitin is absorbed by the living body over several months. To investigate the slow releasing property, it was implanted in thigh muscle of mice and rabbit. Pt level in different organs and in urine was measured at regular intervals. Pt level in implanted muscles was higher in comparison to low serum level in mice. It was released slowly over 1 to 2 months in mice, whereas in rabbit it took about three weeks. Pt releasing period of the Plachitin was different according to the adopted method of implantation. Anticancer effect of Plachitin was investigated by injecting 180 sarcoma cells in mouse peritoneal cavity and subsequent implantation of Plachitin. In control groups chitin was used instead of Plachitin. The survival rate of mice in the Plachitin group after 14 days was higher than in the chitin group, and the anticancer effect of the Plachitin was confirmed.

[Different treatment methods for bone regeneration. A report on the Symposium on Different Treatment Methods for Bone Regeneration of Biomaterials Geistlich of 6 April 1995 in Zurich]
Wallkamm, B. (1995), Schweiz Monatsschr Zahnmed 105(7): 994-5.

[Durability of biomaterials and osteosynthesis materials]
Bourgois, R. (1972), Acta Orthop Belg 38 Suppl 1: 13-5.

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