Shaping ability of protaper next compared with waveone in late-model three-dimensional printed teeth.

BACKGROUND: Comparison of the shaping ability of advanced nickel-titanium (Ni-Ti) instruments is of great interest to the field of endodontics. However, the models used to study canal preparation still lack uniformity, relevance to reality and complexity. The aim of this study was thus to compare the shaping abilities of the ProTaper Next (PN) and WaveOne (WO) Ni-Ti instruments in three-dimensional (3D)-printed teeth, which may overcome the present defects of most real teeth and model teeth including 3D S-shaped canals. METHODS: Six teeth and their corresponding 3D-printed replicas were prepared using the same kind of Ni-Ti instrument. The pre- and post-preparation volumes, surface areas and transportation of the canals were measured to compare the teeth with their replicas. Twenty 3D-printed teeth with S-shaped canals were used to support the preparation study. The S-shaped canals were then scanned to measure their volumes and surface areas. Next, the two kinds of instruments were used to prepare the 3D-printed canals (n = 10 per group). The volume and surface area of the canals, the transportation along the two curvatures and the percentage of unprepared surface area were measured. Micro-CT and VGstudio2.2 (VG2.2) software were used to perform scans and collect data throughout the research. The paired-samples T test and Kruskal-Wallis H test were used for statistical analysis. RESULTS: There was no significant difference between the real canals and the printed ones post-preparation (P > .05). The printed S-shaped root canals had a unified shape, with a small standard deviation and range. The WO group had higher mean values for the volume and superficial area measurements compared with the PN group (P < .05). No differences in the untouched areas were found between the two systems (P > .05). PN caused less transportation at the apical curve than WO did (P < .05). CONCLUSIONS: In conclusion, 3D-printed teeth are suitable for the study of Ni-Ti rotary instruments. Furthermore, the PN rotary system caused less transportation at the apical curve than the WO system did in complicated root canal procedures.

A comparison of the shaping ability of three nickel-titanium rotary instruments: a micro-computed tomography study via a contrast radiopaque technique in vitro.

BACKGROUND: Micro-CT (µCT) studies that combine simulated canals with meglucamine diatrizoate to evaluate the shaping ability of nickel-titanium (NiTi) rotary instruments are lacking in the literature. The purpose of this study was to evaluate the shaping ability of three new different nickel-titanium rotary instruments in simulated root canals using µCT. METHODS: Thirty simulated root canals with a curvature of 60° were randomly allocated into the following 3 groups (n = 10): Group 1, ProTaper Universal (PTU) rotary system; Group 2, Reciproc single-file system; and Group 3, K3XF rotary system. Pre- and post-instrumented images of simulated canals were scanned with µCT via a radiopaque contrast technique to build a 3-dimensional (3D) model. Canal transportation, volumetric change and centring ability were evaluated in each group. Instrument failure and preparation time were also recorded. The Kruskal-Wallis test was used for statistical analysis and the significance level was set at p = 0.05. RESULTS: Reciproc produced greater volume change in the apical part of the canals compared with PTU and K3XF (p < 0.05). K3XF exhibited less transportation and better centring ability at the 2- and 3-mm levels from the apical foramen compared with PTU and Reciproc (p < 0.05). There were no significant differences in the centring ratio and transportation between PTU and Reciproc. Preparation time was significantly shorter in the Reciproc group (p < 0.05). CONCLUSIONS: Under the conditions of our study, all of the canals were 3D reconstructed successfully via the radiopaque contrast technique. Reciproc showed enhanced apical volume changes and K3XF exhibited better centring ability when compared with other groups.

The prevalence and risk indicators of tooth wear in 12- and 15-year-old adolescents in Central China.

BACKGROUND: Tooth wear has been investigated in numerous countries, and the prevalence has varied. However, the data on tooth wear in China are scarce. The aim of this study was to describe the prevalence of tooth wear and to investigate the relative indicators associated with tooth wear in 12- and 15-year-old adolescents in Wuhan City, Hubei Province, Central China. METHODS: A cross-sectional descriptive study was undertaken among 720 adolescents in Hubei Province, Central China. The age groups in this study were 12- and 15-year-old, and each group consisted of 360 participants in which females and males represented 50 % each. A modified version of the Basic Erosive Wear Examination (BEWE) tooth wear index was used for the buccal, cervical, occlusal/incisal and lingual surfaces of all of the teeth in the 720 adolescents. All of the participants were asked to answer a questionnaire consisting of questions about their current and historical dietary habits and oral hygiene. RESULTS: The prevalence of tooth wear was 18.6 and 89.4 % in 12- and 15-year-old adolescents, respectively. The prevalence rates of dentin exposure were 1.9 and 5.6 %, respectively. A significantly higher prevalence of tooth wear and dentin exposure in 15-year-old adolescents was found than in 12-year-old adolescents (p < 0.001 and p = 0.011). Several factors such as drinking soft drinks and fruit juices immediately after sports, taking aspirin, reflux, unilateral chewing, tooth brushing once daily or less often, duration of brushing less than 2 min and swimming in the summer were found to be associated with tooth wear. CONCLUSIONS: Tooth wear in 12- and 15-year-old adolescents in Central China is a significant problem and should receive greater attention. The prevalence of tooth wear increases with age and associated with socio-behavioral risk factors.

Rational design of viscoelastic hydrogels for periodontal ligament remodeling and repair.

The periodontal ligament (PDL) is a distinctive yet critical connective tissue vital for maintaining the integrity and functionality of tooth-supporting structures. However, PDL repair poses significant challenges due to the complexity of its mechanical microenvironment encompassing hard-soft-hard tissues, with the viscoelastic properties of the PDL being of particular interest. This review delves into the significant role of viscoelastic hydrogels in PDL regeneration, underscoring their utility in simulating biomimetic three-dimensional microenvironments. We review the intricate relationship between PDL and viscoelastic mechanical properties, emphasizing the role of tissue viscoelasticity in maintaining mechanical functionality. Moreover, we summarize the techniques for characterizing PDL's viscoelastic behavior. From a chemical bonding perspective, we explore various crosslinking methods and characteristics of viscoelastic hydrogels, along with engineering strategies to construct viscoelastic cell microenvironments. We present a detailed analysis of the influence of the viscoelastic microenvironment on cellular mechanobiological behavior and fate. Furthermore, we review the applications of diverse viscoelastic hydrogels in PDL repair and address current challenges in the field of viscoelastic tissue repair. Lastly, we propose future directions for the development of innovative hydrogels that will facilitate not only PDL but also systemic ligament tissue repair. STATEMENT OF SIGNIFICANCE.

Matrix metalloproteinase-responsive hydrogels with tunable retention for on-demand therapy of inflammatory bowel disease.

Therapeutic options for addressing inflammatory bowel disease (IBD) include the administration of an enema to reduce intestinal inflammation and alleviate associated symptoms. However, uncontrollable retention of enemas in the intestinal tract has posed a long-term challenge for improving their therapeutic efficacy and safety. Herein we have developed a protease-labile hydrogel system as an on-demand enema vehicle with tunable degradation and drug release rates in response to varying matrix metalloproteinase-9 (MMP-9) expression. The system, composed of three tailored hydrogel networks, is crosslinked by poly (ethylene glycol) (PEG) with 2-, 4- and 8-arms through dynamic hydrazone bonds to confer injectability and generate varying network connectivity. The retention time of the hydrogels can be tuned from 12 to 36 h in the intestine due to their different degradation behaviors induced by MMP-9. The drug-releasing rate of the hydrogels can be controlled from 0.0003 mg/h to 0.278 mg/h. In addition, injection of such hydrogels in vivo resulted in significant differences in therapeutic effects including MMP-9 consumption, colon tissue repair, reduced collagen deposition, and decreased macrophage cells, for treating a mouse model of acute colitis. Among them, GP-8/5-ASA exhibits the best performance. This study validates the effectiveness of the tailored design of hydrogel architecture in response to pathological microenvironment cues, representing a promising strategy for on-demand therapy of IBD. STATEMENT OF SIGNIFICANCE: The uncontrollable retention of enemas at the delivery site poses a long-term challenge for improving therapeutic efficacy in IBD patients. MMP-9 is highly expressed in IBD and correlates with disease severity. Therefore, an MMP-9-responsive GP hydrogel system was developed as an enema by linking multi-armed PEG and gelatin through hydrazone bonds. This forms a dynamic hydrogel characterized by in situ gelation, injectability, enhanced bio-adhesion, biocompatibility, controlled retention time, and regulated drug release. GP hydrogels encapsulating 5-ASA significantly improved the intestinal phenotype of acute IBD and demonstrated notable therapeutic differences with increasing PEG arms. This method represents a promising on-demand IBD therapy strategy and provides insights into treating diseases of varying severities using endogenous stimulus-responsive drug delivery systems.

Polydopamine-modified konjac glucomannan scaffold with sustained release of vascular endothelial growth factor to promote angiogenesis.

The fabrication of scaffolds capable of the sustained release of the vascular endothelial growth factor (VEGF) to promote angiogenesis for a long time remains a challenge in tissue engineering. Here, we report a facile approach for effectively fabricating a bioactive scaffold that gradually releases VEGF to promote angiogenesis. The scaffold was fabricated by coating polydopamine (PDA) on a konjac glucomannan (KGM) scaffold, followed by the surface immobilization of VEGF with PDA. The resulting VEGF-PDA/KGM scaffold, with a porous and interconnected microstructure (392 µm pore size with 84.80 porosity), combined the features of long-term biodegradability (10 weeks with 51 % degradation rate), excellent biocompatibility, and sustained VEGF release for up to 21 days. The bioactive VEGF-PDA/KGM scaffold exhibited multiple angiogenic activities over time, as confirmed by in vivo and in vitro experiments. For example, the scaffold significantly promoted the attachment and proliferation of human umbilical vein endothelial cells and the formation of vascular tubes in vitro. Moreover, the in vivo results demonstrated the formation and maturation of blood vessels after subcutaneous implantation in rats for four weeks. This promising strategy is a feasible approach for producing bioactive materials that can induce angiogenesis in vivo. These findings provide a new avenue for designing and fabricating biocompatible and long-term biodegradable scaffolds for sustained VEGF release to facilitate angiogenesis.

Dextran-based self-healing hydrogels formed by reversible diels-alder reaction under physiological conditions.

A dextran-based self-healing hydrogel is prepared by reversible Diels-Alder reaction under physiological conditions. Cytocompatible fulvene-modified dextran as main polymer chains and dichloromaleic-acid-modified poly(ethylene glycol) as cross-linkers are used. Both macro- and microscopic observation as well as the rheological recovery test confirm the self-healing property of the dextran-l-poly(ethylene glycol) hydrogels ("l" means "linked-by"). In addition, scanning electrochemical microscopy is used to qualitatively and quantitatively in situ track the self-healing process of the hydrogel for the first time. It is found that the longitudinal depth of scratch on hydrogel surface almost completely healed at 37 °C after 7 h. This work represents a facile approach for fabrication of polysaccharide self-healing hydrogel, which can be potentially used in several biomedical fields.

Global quantitative proteomic analysis profiles of host protein expression in response to enterovirus A71 infection in bronchial epithelial cells based on tandem mass tag (TMT) peptide labeling coupled with LC-MS/MS uncovers the key role of proteasome in virus replication.

Enterovirus A71 (EV-A71) is a neurotropic human pathogen which mainly caused hand, foot and mouth disease (HFMD) mostly in children under 5 years-old. Generally, EV-A71-associated HFMD is a relatively self-limiting febrile disease, but there will still be a small percentage of patients with rapid disease progression and severe neurological complications. To date, the underlying mechanism of EV-A71 inducing pathological injury of central nervous system (CNS) remains largely unclear. It has been investigated and discussed the changes of mRNA, miRNA and circRNA expression profile during infection by EV-A71 in our previous studies. However, these studies were only analyzed at the RNA level, not at the protein level. It's the protein levels that ultimately do the work in the body. Here, to address this, we performed a tandem mass tag (TMT) peptide labeling coupled with LC-MS/MS approach to quantitatively identify cellular proteome changes at 24 h post-infection (hpi) in EV-A71-infected 16HBE cells. In total, 6615 proteins were identified by using TMT coupled with LC-MS/MS in this study. In the EV-A71- and mock-infected groups, 210 differentially expressed proteins were found, including 86 upregulated and 124 downregulated proteins, at 24 hpi. To ensure the validity and reliability of the proteomics data, 3 randomly selected proteins were verified by Western blot and Immunofluorescence analysis, and the results were consistent with the TMT results. Subsequently, functional enrichment analysis indicated that the up-regulated and down-regulated proteins were individually involved in various biological processes and signaling pathways, including metabolic process, AMPK signaling pathway, Neurotrophin signaling pathway, Viral myocarditis, GABAergic synapse, and so on. Moreover, among these enriched functional analysis, the "Proteasome" pathway was up-regulated, which has caught our attention. Inhibition of proteasome was found to obviously suppress the EV-A71 replication. Finally, further in-depth analysis revealed that these differentially expressed proteins contained distinct domains and localized in different subcellular components. Taken together, our data provided a comprehensive view of host cell response to EV-A71 and identified host proteins may lead to better understanding of the pathogenic mechanisms and host responses to EV-A71 infection, and also to the identification of new therapeutic targets for EV-A71 infection.

Novel phosphorescent hydrogels based on an Ir(III) metal complex.

Novel phosphorescent hydrogels have been explored by immobilizing an Ir(III) metal complex into the matrices of hydrogels. FTIR spectra demonstrate that the Ir(III) -PNaAMPS hydrogel is achieved by irreversible incorporation of positively charged [Ir(ppy)(2)(dmbpy)]Cl (ppy = 2-phenylpyrine, dmbpy = 4,4'-dimethyl-2,2'-bipyridine) into negatively charged poly(2-acrylamido-2-methylpropane sulfonic acid sodium) (PNaAMPS) hydrogel via electrostatic interaction. The photoluminescent spectra indicate that the Ir(III)-PNaAMPS hydrogel exhibits stable phosphorescence. In vitro cultivation of human retinal pigment epithelial cells demonstrates the cytocompatibility of the Ir(III)-PNaAMPS hydrogel. This work herein represents a facile pathway for fabrication of phosphorescent hydrogels.

Hydrophilic co-assembly of wheat gluten proteins and wheat bran cellulose improving the bioavailability of curcumin.

Low-cost wheat by-products have been modified to become an effective delivery system for curcumin. Wheat bran cellulose (WBC) and wheat gluten proteins (WPs) were co-assembled by a pH cycle and addition of sodium tripolyphosphate (STP). Fluorescence spectroscopy and zeta-potential evidenced that the embedding of WBC into the WPs favored the formation composites a relative unfolding state. Modifying the nanocomposite with STP lowered the Dh and PDI of the co-assembled structure. The nanocomplexes had a typical core-shell structure according to TEM characterization, where proteins aggregate to form a hydrophobic core and the hydrophilic WBC and STP crosslinked to form the shell. To improve the bioavailability of curcumin, it was encapsulated in WWBCs composites by participating in their structural co-assembly. In vitro simulated gastrointestinal digestion experiments showed that the curcumin encapsulated in WWBCs possessed gastrointestinal slow and controlled release function, with a final release of curcumin of 77.8 ± 2.3 %.

A novel approach for efficient fabrication of chitosan nanoparticles-embedded bacterial nanocellulose conduits.

Incorporation of chitosan (CS) into Bacterial nanocellulose (BNC) matrix is of great interests in biomedical field due to the advantageous properties of each material. However, the conventional strategies result in poor composite effect with low efficiency. In this study, the three-dimensional fibrillar network of BNC was utilized as a template for the first time to homogeneously disperse CS to form nanoparticles (CSNPs) in BNC matrix via ionic gelation method, to develop chitosan nanoparticles-embedded bacterial nanocellulose (CSNPs-BNC) composites. This composite method is simple and efficient, without introducing dispersants and crosslinking agents, while retaining the mechanical properties and native 3D network structure of BNC. The CSNPs-BNC composites had excellent antibacterial activity to support potential clinical application. The CSNPs-BNC composites could promote the adhesion and proliferation of Schwann cells, and demonstrate good biocompatibility both in vitro and in vivo. The results indicated that CSNPs-BNC can provide a promising candidate for biomedical applications.

Neural Stem Cell-Laden Self-Healing Polysaccharide Hydrogel Transplantation Promotes Neurogenesis and Functional Recovery after Cerebral Ischemia in Rats.

Exploring a strategy to effectively repair cerebral ischemic injury is a critical requirement for neuroregeneration. Herein, we transplanted a neural stem cell (NSC)-laden self-healing and injectable hydrogel into the brains of ischemic rats and evaluated its therapeutic effects. We observed an improvement in neurological functions in rats transplanted with the NSC-laden hydrogel. This strategy is sufficiently efficient to support neuroregeneration evidenced by NSC proliferation, differentiation, and athletic movement recovery of rats. This therapeutic effect relates to the inhibition of the astrocyte reaction and the increased expression of vascular endothelial growth factor. This work provides a novel approach to repair cerebral ischemic injury.

Modification of wheat bran insoluble dietary fiber with carboxymethylation, complex enzymatic hydrolysis and ultrafine comminution.

To improve the industrial application of wheat bran insoluble dietary fiber (W-IDF), three modification methods (carboxymethylation, complex enzymatic hydrolysis, and ultrafine comminution) were compared on the basis of structural, physicochemical, functional, and antioxidant properties of W-IDF. FT-IR, DSC and SEM analysis showed that modifications contributed to alteration in morphology and arrangement of chemical bonds in W-IDF. Carboxymethylation effectively improved the water retention (WRC), water swelling (WSC), and glucose adsorption capacities (GAC); complex enzymatic hydrolysis greatly improved the oil retention (ORC), GAC, and nitrite ion adsorption capacities (NIAC). Although ultrafine comminution reduced the WRC and ORC, while positively influenced the GAC and NIAC. Moreover, total phenol content, total antioxidant capacity, DPPH radical scavenging capacity, Fe2+ chelating capacity and total reducing power were improved in modified W-IDF. Our results confirmed that carboxymethylation can improve the nutritive quality and sensory properties of W-IDF (nutritive ingredient) in food products.

A self-healing hydrogel as an injectable instructive carrier for cellular morphogenesis.

Transplantation of progenitor cells can accelerate tissue healing and regenerative processes. Nonetheless, direct cell delivery fails to support survival of transplanted cells or long-term treatment of vascular related diseases due to compromised vasculature and tissue conditions. Using injectable hydrogels that cross-link in situ, could protect cells in vivo, but their sol-gel transition is time-dependent and difficult to precisely control. Hydrogels with self-healing properties are proposed to address these limitations, yet current self-healing hydrogels lack bio-functionality, hindering the morphogenesis of delivered cells into a tissue structure. Here we establish a gelatin (Gtn)-based self-healing hydrogel cross-linked by oxidized dextran (Odex) as an injectable carrier for delivery of endothelial progenitors. The dynamic imine cross-links between Gtn and Odex confer the self-healing ability to the Gtn-l-Odex hydrogels following syringe injection. The self-healing Gtn-l-Odex not only protects the progenitors from injected shear force but it also allows controllable spatial/temporal placement of the cells. Moreover, owing to the cell-adhesive and proteolytic sites of Gtn, the Gtn-l-Odex hydrogels support complex vascular network formation from the endothelial progenitors, both in vitro and in vivo. This is the first report of injectable, self-healing hydrogels with biological properties promoting vascular morphogenesis, which holds great promise for accelerating the success of regenerative therapies.

Dual Cross-Linked Biofunctional and Self-Healing Networks to Generate User-Defined Modular Gradient Hydrogel Constructs.

Gradient hydrogels have been developed to mimic the spatiotemporal differences of multiple gradient cues in tissues. Current approaches used to generate such hydrogels are restricted to a single gradient shape and distribution. Here, a hydrogel is designed that includes two chemical cross-linking networks, biofunctional, and self-healing networks, enabling the customizable formation of modular gradient hydrogel construct with various gradient distributions and flexible shapes. The biofunctional networks are formed via Michael addition between the acrylates of oxidized acrylated hyaluronic acid (OAHA) and the dithiol of matrix metalloproteinase (MMP)-sensitive cross-linker and RGD peptides. The self-healing networks are formed via dynamic Schiff base reaction between N-carboxyethyl chitosan (CEC) and OAHA, which drives the modular gradient units to self-heal into an integral modular gradient hydrogel. The CEC-OAHA-MMP hydrogel exhibits excellent flowability at 37 °C under shear stress, enabling its injection to generate gradient distributions and shapes. Furthermore, encapsulated sarcoma cells respond to the gradient cues of RGD peptides and MMP-sensitive cross-linkers in the hydrogel. With these superior properties, the dual cross-linked CEC-OAHA-MMP hydrogel holds significant potential for generating customizable gradient hydrogel constructs, to study and guide cellular responses to their microenvironment such as in tumor mimicking, tissue engineering, and stem cell differentiation and morphogenesis.

[Management of oral diseases during pregnancy].

Management of oral diseases during pregnancy prefers to be a comprehensive oral health care strategy throughout pre-pregnant, pregnant and prenatal stages. It provides guidance not only to promote the overall health in pregnant women, but also concern fetus development and children's oral health. Pregnancy is a time of particular vulnerability in terms of oral health due to complex physical and physiological changes. Physicians and dentists are responsible for providing professional medical care and treatment following clinical guidelines especially for pregnancy. It is also an opportune time in pregnancy to educate women about oral health care and preventing oral problems in young children. This article reviews the commonly occurring oral problems and their pathogenesis during pregnancy, dental procedures that can be carried out by physicians and preventive strategies that could be helpful in promoting oral health in both pregnant women and young children.

A possible water-soluble inducer for synthesis of cellulase in Aspergillus niger.

The synthesis of cellulase in filamentous fungi can be triggered by several inducers. In this study, a bamboo-shoot shell pretreated with Pleurotus ostreatus could promote the formation of cellulases in Aspergillus niger. Further identification, including UPLC-TOF-MS, ultrafiltration, and FT-IR, denoted that the soluble inducer was not a traditional disaccharide but a type of modified lignin polymer. This revelation may result in incipient strategies to ameliorate cellulase productivity.

Prevalence and Indicators of Tooth Wear among Chinese Adults.

Numerous epidemiological studies have focused on the prevalence and related indicators of tooth wear. However, no sufficient studies have been conducted with Chinese adults. The purpose of this study was to assess the prevalence of tooth wear and identify related indicators among adults aged 36 to 74 years in Wuhan City, P.R. China. A cross-sectional and analytic study was conducted with 720 participants, aged 35-49 yrs and 50-74 yrs, in 2014. Each age group included 360 participants, of which 50% were males and 50% were females. All participants completed a questionnaire before examination. Tooth wear was assessed using the modified Basic Erosive Wear Examination (BEWE) index. The data were analyzed using the chi-square test and binary logistic regression analysis. The prevalence of tooth wear was 67.5% and 100% in the 35-49 and 50-74 age groups, respectively. The prevalence of dentin exposure was 64.7% and 98.3%, respectively. A significantly higher prevalence of tooth wear and dentin exposure was found in the 50-74 yr group than in the 35-49 yr group (p < 0.05). Critical indicators of tooth wear and dentin exposure included high frequency of acidic drinks and foods consumption, low socio-economic status, and unilateral chewing. The frequency of changing toothbrushes and the habit of drinking water during meals were associated with tooth wear. In addition, the usage of hard-bristle toothbrushes and consuming vitamin C and aspirin were found to be linked with dentin exposure. In conclusion, the prevalence of tooth wear and dentin exposure observed in Chinese adults was high, and the results revealed an association between tooth wear and socio-behavioral risk indicators.

Aluminum hypophosphite microencapsulated to improve its safety and application to flame retardant polyamide 6.

Aluminum hypophosphite (AHP) is an effective phosphorus-containing flame retardant. But AHP also has fire risk that it will decompose and release phosphine which is spontaneously flammable in air and even can form explosive mixtures with air in extreme cases. In this paper, AHP has been microencapsulated by melamine cyanurate (MCA) to prepare microencapsulated aluminum hypophosphite (MCAHP) with the aim of enhancing the fire safety in the procedure of production, storage and use. Meanwhile, MCA was a nitrogen-containing flame retardant that can work with AHP via the nitrogen-phosphorus synergistic effect to show improved flame-retardant property than other capsule materials. After microencapsulation, MCA presented as a protection layer inhibit the degradation of AHP and postpone the generation of phosphine. Furthermore, the phosphine concentration could be effectively diluted by inert decomposition products of MCA. These nonflammable decomposition products of MCA could separate phosphine from air delay the oxidizing reaction with oxygen and decrease the heat release rate, which imply that the fire safety of AHP has been improved. Furthermore, MCAHP was added into polyamide 6 to prepare flame retardant polyamide 6 composites (FR-PA6) which show good flame retardancy.

Influence of culture conditions on laccase production and isozyme patterns in the white-rot fungus Trametes gallica.

Laccase production by the white-rot fungus Trametes gallica was studied, using twelve different media under static or shaking condition. The results indicated that organic nitrogen sources such as tryptone and peptone strongly improved laccase production. The application of an amino acid mixture and a lignin preparation also increased the formation of laccase, which was not observed in the presence of potato extract. Native polyacryl amide gel electrophoresis (PAGE) followed by laccase activity staining using guaiacol as the substrate was performed to analyze the laccase isozyme patterns under the different culture conditions employed. Zymograms revealed a total of twenty different laccase activity bands that appeared in individual patterns, dependent on the respective culture condition applied. This indicates that both the medium composition and the mode of incubation (static or shaking) influenced the laccase isozyme gene expression. This was the first time to report so many laccase isozymes in a fungus. Native PAGE with silver staining showed that laccases were the main protein productions in several media providing a potentially convenient way in purifying laccases from T. gallica.