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16 recordsLinked to original sources
PubMed1978

Antigenic properties of Bioplast.

The influence of heat treatment (at 150 +/- 2 degrees C for 2 hours) on the antigenicity of human Bioplast fibrin powder and human fibrin Bioplast plates was tested in an experimental study. Untreated and heat-treated fibrin powder with incomplete Freund's adjuvant was subcutaneously injected in rabbits. In addition, untreated and heat-treated plates, to which incomplete Freund's adjuvant was added, were subcutaneously implanted. A booster dose was given 8 weeks after the start of the experiment. Blood samples were collected up to 4 weeks after the second injection or implantation, and the sera were tested for precipitating antibodies by the double diffusion technique (OUCHTERLONY'S method). Unlike previous investigators, we found antibodies in sera from rabbits injected or implanted with heat-treated Bioplast products. Thus, the claim that the antigenic properties of all kinds of fibrin can be fully eliminated by heat treatment does not appear to be tenable. In order to avoid the risk of sensitization in man, it is probably advisable to use only human fibrin for the production of Bioplast fibrin powder and Fibrin Bioplast plates for clinical use in human beings.

Animals↗
PubMed2026

Bioplastic biodegradability shapes microbial communities in a coastal brackish environment.

Microorganisms are metabolically versatile and central to marine ecosystems, yet the potential of marine microbial communities to degrade different bioplastics and the effect of environmental factors are poorly understood. Employing multi-seasonal in situ and in vitro experiments, we assessed the biodegradation of six commonly used bio-based bioplastic materials at a coastal site in the brackish Baltic Sea and characterized the associated microbial communities using metagenomics and metatranscriptomics. Cellulose acetate (CA), polybutylene succinate (PBS), and polyhydroxybutyrate/valerate (PHB) degraded at varying rates across materials, seasons, and experimental settings, with up to 28% weight attrition after 97 weeks in situ (CA) and 56% carbon loss as CO2 after 4 weeks in vitro (PBS). The three biodegraded plastics developed similar microbial communities that differed markedly from those on the other materials (cellulose acetate propionate, polyamide, and polyethylene) and in the water column. The main microbial populations on the biodegraded plastics included aerobic and facultative anaerobic heterotrophs with a broad capacity for carbohydrate metabolism. Populations with the potential for nitrogen fixation and denitrification were more prevalent on the biodegraded plastics, suggesting that bioplastic biodegradation is constrained by and coupled to the marine nitrogen cycle. Based on the metatranscriptomic signal of key genes involved in the initial hydrolysis of CA, PBS, and PHB, we identified diverse microbial populations that can potentially drive the biodegradation of these materials in the Baltic Sea, many of which encoded the potential to degrade multiple bioplastics. We propose the term 'bioplastisphere' to denote the distinctive microbial communities associated with biodegradable plastics.

Seawater↗
PubMed1977

An introductory report on the use of Bioplast in ophthalmic surgery.

Bioplast is an excellent material for implants. It lends itself readily to cutting and suturing and is easily applied. It is highly suited to ophthalmic surgery. It has the great advantage of having no antigenic properties and is quickly absorbed. Our cases recovered without complications, and the results were satisfactory both functionally and cosmetically. For these reasons we recommend Bioplast in ophthalmology.

Fibrin↗
PubMed1977

Skin replacement with Bioplast fibrin in Ophthalmology.

The study includes 40 cases of skin replacement performed by an ophthalmologist over a period of 4 years. An absorbable implant material, Bioplast fibrin, was used as a graft following the extirpation of 12 eyelid tumors, the treatment of eight fresh, destructive skin injuries, and the removal of deforming scars around the eyes, in 20 cases. The biocompatible implant provided barrier properties preventing infection or excessive fluid loss. The resorption rate was adjusted to 3-4 weeks. These grafts were gradually replaced by new epithelial tissue growing in from the periphery of the wound edge. The new tissue had the elasticity and cosmetic appearance of surrounding skin. Thus, small periorbital skin tumors can now be removed without the necessity of doing a split thickness skin graft to cover the defect.

Adolescent↗
PubMed1977

Bioplast fibrin implants in nasoseptal perforation.

This study includes 9 cases of nasoseptal perforation following submucous septectomy. Sheets from Bioplast fibrin, an absorbable biomaterial, were implanted to prevent thepersistence of perforations. Postoperative mucosal growth on both implant surfaces ensured closure in 6 of the 9 cases. The method has the advantage of simplicity and it is commendable in the case of smaller defects when the mucosa is not markedly atrophic.

Female↗
PubMed1976

Bioplast fibrin coagulum in large cystic defects of the jaw.

The present study comprises a series of 85 patients with jaw cysts with a diameter greater than 20 mm, the majority in the 30-50 mm group. Following enucleation of the cyst, a coagulum consisting of Bioplast fibrin powder, thrombin, the patient's venous blood and an antibiotic was implanted and primary closure performed. The clinical course was uneventful and the operative area healed by first intention in all cases. The nursing period was shortened. Radiographic follow-up showed rapid ossification. The favorable results are attributed to the absence of dead spaces, the role of fibrin in the regeneration process, and a retarded effect of the antibiotic.

Adolescent↗
PubMed1979

Bioplast fibrin film for conjunctival replacement.

The study includes 43 cases of conjunctival grafting in chemical burns and traumatic pterygium. Resorbable Bioplast fibrin film was used as a readily available, biocompatible conjunctival subsitute. The implant was absorbed and the site occupied by fresh conjunctival tissue in a few weeks. The composition of tear proteins was restored to normal as fast as after free conjunctival grafting. The results were also satisfactory in terms of cosmetics.

Biocompatible Materials↗
PubMed1979

Experimental dermatoplasty of skin defects with an absorbable bioplastic preparation.

Experimental dermatoplasty was performed with fibrin sponge preparation in the rabbit, during the course of which the whole skin thickness was substituted. The fibrin sponge was fixed to the skin-edges with surgical adhesive. The gradually absorbed fibrin was replaced by the migrating epithelium such that epithelization developed gradually. In special cases this method can be recommended for clinical purposes.

Animals↗
PubMed2025

Versatile sugar and valerate metabolic pathways in Paraburkholderia xenovorans LB400 enable tailored poly(3-hydroxybutyrate-co-3-hydroxyvalerate) production.

Poly(3-hydroxybutyrate) and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) polymers are accumulated by diverse prokaryotes. Their distinct monomer compositions enable their use as tailored bioplastics. The aims were to characterize the poly(3-hydroxybutyrate) and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) synthesis by Paraburkholderia xenovorans LB400 using different sugars and valerate, and to gain genome-oriented insights into polyhydroxyalkanoate production. d-Glucose, d-mannitol, d-gluconate, and d-xylose were evaluated as sole carbon sources or supplemented with valerate. Polyhydroxyalkanoates synthesized by strain LB400 were characterized through GC-MS, GC-FID, FTIR, and 1H and 13C-NMR. P. xenovorans LB400 reached 1.00-1.39 g L-1 of dry cell weight (DCW) with a P(3HB) content of 21-43% w w-1 when grown on different sugars. The addition of valerate to the sugar-grown LB400 cultures yielded a DCW of 1.79 to 2.29 g L-1 and a P(3HB-co-3HV) content of 50.0‒51.2% w w-1, with varying 3HV compositions (28‒43 mol%). The highest 3HV incorporation was observed with d-xylose and valerate. Genomic analyses of strain LB400 revealed key elements of sugar metabolism influencing growth, polymer accumulation, and monomer composition. LB400 genome encodes the PhaJ-like R-specific hydratase and FadJ epimerase, which are potentially useful for modulating copolymer composition. PHA production under bioreactor conditions was evaluated. In a bioreactor fed with d-glucose, LB400 achieved a P(3HB) concentration of 2.2 g L-1. These findings highlight the metabolic versatility of P. xenovorans LB400 in utilizing diverse sugars to produce either P(3HB) or tailor-made P(3HB-co-3HV), supporting the development of bioplastics for specific applications. KEY POINTS: • Strain LB400 produced P(3HB-co-3HV) from various sugars and valerate. • Sugar type drives LB400 PHA copolymer synthesis and composition. • Strain LB400 PHA production was scaled up to a bioreactor.

Polyesters↗
PubMed1979

The effects of induced prenatal hypothyroidism on lamb mandibular third primary molars.

Intrauterine thyroidectomies were performed on nine lambs on or about the ninety-sixth postconception day. Seven other control and shamoperated lambs, and the cretin lambs were sacrificed immediately after birth. The mandibles were removed and sectioned at the midline. The right side molars were removed by dissection and caliper measured. The distal cusps of the third primary molars were sectioned, dehydrated, and embedded in Bioplastic. A slow speed diamond saw was used to section the plastic blocks and the embedded teeth. Subsequent grinding and polishing produced high quality 75 micrometer sections of the lamb molar cusps. No significant differences in tooth size or enamel thickness existed. Microscopic examinations show that parts of the cretin enamel were poorly calcified, an observation that was correlated to the intrauterine thyroidectomies. The data suggest that hypothyroidism alters ameloblastic activity during the secretory phase of enamel formation.

Amelogenesis↗
PubMed2026

Multiomic insights into fungal polylactic acid degradation: Metabolic adaptation and hydrolytic mechanisms of Sporobolomyces pararoseus.

Polylactic acid (PLA), a biodegradable polyester from renewable resources, is a sustainable alternative to petrochemical plastics. However, its environmental degradation is inefficient naturally, requiring specific microbial activities. While bacterial PLA-degrading mechanisms are well documented, fungal degrading systems-particularly their molecular mechanisms-are underexplored.We isolated Sporobolomyces pararoseus ZRQ01 from the gut microbiota of PLA-fed mealworms. This fungal strain noticeably degraded PLA in PLA-containing medium supplemented with 2% glucose. Biodegradation assays revealed 22.8% loss of the PLA film weight after 35 days of incubation, and scanning electron microscopy confirmed extensive surface erosion and pore formation. Integrated transcriptomic and proteomic analyses, together with the reference genome of S. pararoseus ZRQ01, revealed that S. pararoseus ZRQ01 upregulates hydrolytic enzymes at both transcript and protein levels to cleave PLA into lactic acid. After lactic acid is transferred into S. pararoseus ZRQ01 cells by monocarboxylate transporters with increased abundance, it is assimilated by pathways of pyruvate metabolism and the TCA cycle with increased protein abundance. Intriguingly, upregulation of genes in autophagy-related and MAPK signaling pathways underscores an adaptive stress response potentially supporting cellular homeostasis and degradation-related gene expression. Our results highlight S. pararoseus ZRQ01's metabolic potential for bioremediation and offer insights into fungal bioplastic degradation pathways.

Polyesters↗
PubMed1977

Bone remodeling in periodontal lesions.

This study was designed to investigate sites of major alveolar bone formation as a result of resorption of the interdental crest in periodontal lesions. Bone samples were taken from twelve patients requiring surgery as part of their periodontal treatment. Tetracycline was used in all cases to label bone recently formed. The selected areas were periodontal pockets ranging in depth from 6 to 8 mm. The bone deformities were of crater-form configuration. The buccal and lingual plates were removed. Later, the dehydrated speciemns were embedded in bioplastic and cut to sections 70 mu thick. Controls were healthy pieces of bone taken from the same patient in unaffected areas. Yellow fluorescent tetracycline labeling was observed in both periosteal and trabecular bone. In the trabecular bone, labeling was exhibited in the lamella of some Haversian systems, away form the bone resorption. There was a direct relationship between bone resorption and bone apposition as seen by the presence of tetracycline in the buccal and lingual alveolar plates. Controls showed only minimal labeling. The results of this study have posed the question as to whether inflammation could be the stimulus in the reactivation of osteocytes or bone formation, in the buccal and lingual walls of the periodontal lesions.

Alveolar Process↗
PubMed1978

Treatment with oxidized cellulose of the resection surface of the lung.

Segment resection was performed in 15 dogs. The resected surface was covered with absorbable cellulose bioplast (Surgicel)R and fixed by the tissue adhesive Histoacryl-N-Blau. The results were checked by gross and microscopic examinations which showed that the gradually absorbed material had been replaced by a layer of connective tissue. The method is recommended for use in human operations.

Absorption↗
PubMed2026

Biotic and abiotic degradation of PHAs: mechanisms, environments, and potential applications of degradation products.

This review seeks to compile Polyhydroxyalkanoates (PHAs) degradation studies published over the past 20 years. It highlights the effect of physical properties, such as crystallinity and molecular weight, on the decomposition rate of these molecules. Both biotic processes, mediated by bacteria, fungi, and enzymes, as well as abiotic processes, such as hydrolysis and thermal degradation, are analyzed. A repertoire of diverse microorganisms, including their metabolic pathways and enzymes for PHA breakdown, is presented. Furthermore, this review presents the decomposition of PHAs in various environments, such as soil and seawater, highlighting their potential as a sustainable alternative. Finally, the resulting degradation products are described, emphasizing their potential applications in medicine and industry. Although degradation of PHAs has been extensively studied through these years, several knowledge gaps remain undisclosed, including the degradation of diverse polyester monomers. PHAs comprise numerous monomer compositions with variable properties, which present opportunities for different applications but pose a challenge in their degradation. The reader of this review can extract useful information for both the production of PHAs and their potential applications.

Biodegradation↗