PURPOSE: The aim of the present study was to evaluate the biocompatibility and barrier function of mussel adhesive protein (MAP)-loaded collagen membranes in guided bone regeneration (GBR). METHODS: Eight male New Zealand white rabbits were used. Four circular defects (diameter: 8 mm) were created in the calvarium of each animal. The defects were randomly assigned to 1) a negative control group, 2) a cyanoacrylate (CA)-loaded collagen membrane group (the CA group), 3) a MAP-loaded collagen membrane group (the MAP group), and 4) a group that received a polycaprolactone block with MAP-loaded collagen membrane (the MAP-PCL group). Specimens were harvested at 2 weeks (n=4) and 8 weeks (n=4) postoperatively for observational histology and histometric analysis. RESULTS: In the histologic analysis, MAP was completely absorbed without any byproducts. In contrast, some of the CA adhesive remained, showing an inflammatory reaction, at 8 weeks. In the MAP-PCL group, the MAP-loaded collagen membranes served as a barrier membrane despite their fast degradation in GBR. No significant difference was found in the amount of new bone between the MAP-PCL and MAP groups (1.82±0.86 mm2 and 2.60±0.65 mm2, respectively). CONCLUSIONS: The MAP-loaded collagen membrane functioned efficiently in this rabbit calvarial GBR model, with excellent biocompatibility. Further research is needed to assess clinical applications in defect types that are more challenging for GBR than those used in the current model.
Adhesives ; Animals ; Biomimetics ; Bivalvia ; Bone Regeneration ; Collagen ; Cyanoacrylates ; Humans ; Male ; Membranes ; Mytilus edulis ; Polymers ; Rabbits ; Skull ; Tissue Adhesives

This study was conducted to investigate the vibrio flora in edible shellfish (Ruditapes philippinarum, Scapharca broughtonii, Batillus cornutus and Mytilus coruscus) which were purchased from seafood-market or collected from shellfish culture bed in Pusan and Masan Bay from May to October 1997. Sixty-three vibrio strains were identified among 438 collected strains. Five species of vibrios [V. alginolyticus (22 strains), V. parahaemolyticus (35 strains), V. costicola (2 strains), L. damsela (V. damsela 2 strains), and V. cholerae non-Ol (2 strains)] were identified by their phenotyfic and biochemical characteristics. Four groups (142 strains) were identified as genus Vibrio by their biological characteristics, but they could not be identified to the species level.
Bays ; Busan ; Cholera ; Mytilus ; Population Characteristics ; Scapharca ; Shellfish* ; Vibrio*

Objective: Owing to antibiotic abuse and the subsequent development of antibiotic resistance, bacterial infection has become one of the most persistent unresolved problems. New antibacterial agents, especially those that are environmental-friendly, are urgently needed. Methods: Melanin extracted by filtration centrifugation and acid and proteolytic hydrolysis was characterized using UV, FTIR, TEM, and XPS. Photothermal conversion was calculated, and the bacteriostatic effects, and , were assessed by plate counting and ratios (%) of wound areas. Results: Natural melanin hydrolyzed by trypsin had good photothermal conversion effects, which resulted in superior bacteriostatic activities. The extracted melanin along with laser NIR irradiation at 808 nm promoted the healing of wounds infected by drug-resistant bacteria and was biocompatible according to toxicity tests and . Conclusion The present findings indicated a safe and efficient method of developing natural antibacterial agents.
Animal Shells ; chemistry ; Animals ; Anti-Bacterial Agents ; pharmacology ; Escherichia coli ; drug effects ; radiation effects ; Escherichia coli Infections ; drug therapy ; Melanins ; pharmacology ; Mytilus edulis ; chemistry ; Photochemical Processes ; Rats ; Rats, Sprague-Dawley ; Staphylococcal Infections ; drug therapy ; Staphylococcus aureus ; drug effects ; radiation effects ; Wound Healing

As a key role in mussel defense system, Mytilin is an important antibacterial peptide isolated from the mussel serum. The structural and functional researches on Mytilin showed that the fragment connecting two beta-sheets in a stable beta-hairpin structure was probably required for antimicrobial activity. To elucidate the structural features and the antimicrobial activity of this fragment, we re-designed and synthesized two peptides corresponding to the main mimic structures of Mytilin-1 from Mytilus coruscus, we named these two peptides Mytilin Derived Peptide-1 and Mytilin Derived Peptide-2, respectively. Using a liquid growth inhibition assay, we evaluated their activity towards Gram-positive, Gram-negative bacteria and fungus. The results showed that both peptides can inhibit the growth of Gram-positive, Gram-negative bacteria and fungus. Besides, these two peptides showed high stability in heat water and human serum. These works laid the foundation for further research on the molecular mechanism of Mytilin and for further exploitation of antibacterial peptides with lower molecular mass and more stable structure.
Amino Acid Sequence ; Animals ; Anti-Infective Agents ; chemical synthesis ; pharmacology ; Antimicrobial Cationic Peptides ; chemical synthesis ; chemistry ; pharmacology ; Molecular Sequence Data ; Mytilus ; chemistry

Mytilin-derived-peptide-1 (MDP-1) and mytilin-derived-peptide-2 (MDP-2) are two truncated decapeptides with reversed sequence synthesized corresponding to the residues 20-29 of mytilin-1 (GenBank Accession No. FJ973154) from M. coruscus. The objective of this study is to characterize the structural basis of these two peptides for their antimicrobial activities and functional differences, and to investigate the inhibitory mechanism of MDPs on Escherichia coli and Sarcina lutea. The structures of MDP-1 and MDP-2 in solution were determined by 1H 2D NMR methods; the antibactericidal effects of MDPs on E. coli and S. lutea were observed by transmitted electron microscopy (TEM). Both MDP-1 and MDP-2 have a well-defined loop structure stabilized by two additional disulfide bridges, which resemble the-hairpin structure of mytilin-1 model. The surface profile of MDPs' structures was characterized by protruding charged residues surrounded by hydrophobic residues. TEM analysis showed that MDPs destroyed cytoplasmic membrane and cell wall of bacteria and the interface between the cell wall and membrane was blurred. Furthermore, some holes were observed in treated bacteria, which resulted in cell death. Structural comparison between MDP-1 and MDP-2 shows that the distribution of positively charged amino acids on the loop of MDPs is topologically different significantly, which might be the reason why MDP-2 has higher activity than MDP-1. Furthermore, TEM results suggested that the bactericidal mechanisms of MDPs against E. coli and S. lutea were similar. Both MDP-1 and MDP-2 could attach to the negatively charged bacterial wall by positively charged amino acid residues and destroy the bacteria membrane in a pore-forming manner, thus cause the contents of the cells to release and eventually cell death.
Animals ; Anti-Infective Agents ; chemical synthesis ; pharmacology ; Antimicrobial Cationic Peptides ; chemical synthesis ; chemistry ; pharmacology ; Cell Wall ; drug effects ; Escherichia coli ; drug effects ; Mytilus ; chemistry ; Sarcina ; drug effects