Fibril matrices created with collagen from the marine fish barramundi for use in conventional three-dimensional cell culture.

Collagen obtained from fish offal (skin, scales, and bones) is required from some religious and ethnic groups, thus indirectly increasing demands for fish collagen for biomedical applications. The limitation of fish collagen is its lower thermal stability compared to mammalian collagen. In this study, we focused on collagen extracted from scales of the marine fish barramundi (Lates calcarifer) and demonstrated the suitability for the collagen to be utilized in collagen fibril matrices (CFM).

Crosslinking Efficacy and Cytotoxicity of Genipin and Its Activated Form Prepared by Warming It in a Phosphate Buffer: A Comparative Study.

The aim of the present study was to compare the acute and cumulative cytotoxicity of intact (n-GE) and warmed genipin (w-GE), while investigating the differences in crosslinking capabilities of these two genipins by rheological and mechanical tests. The n-GE solution was prepared by dissolving genipin powder in a sodium phosphate buffer solution. The w-GE solution was prepared by warming the n-GE solution at 37 °C for 24 h.

In situ gelation properties of a collagen-genipin sol with a potential for the treatment of gastrointestinal ulcers.

We investigated the potential of collagen-genipin sols as biomaterials for treating artificial ulcers following endoscopic submucosal dissection. Collagen sol viscosity increased with condensation, allowing retention on tilted ulcers before gelation and resulting in collagen gel deposition on whole ulcers. The 1.

In Vitro Parallel Evaluation of Antibacterial Activity and Cytotoxicity of Commercially Available Silver-Containing Wound Dressings.

Purpose: This study evaluated the in vitro antibacterial activity and cytotoxicity of various commercially available silver-containing dressings (Ag dressing).

Methods: Biohesive Ag (hydrocolloid, silver sulfadiazine), Aquacel® Ag (nonwoven fabric, ionic silver [Ag]), Algisite™ Ag (nonwoven fabric, Ag), Mepilex® Ag (foam, silver sulfate), and PolyMem® Ag (foam, nanocrystalline silver) were tested for characteristics of Ag release, antibacterial activity, and cytotoxicity. The release of Ag was investigated in cell culture medium at immersion periods of 6, 24, and 48 hours.

Evaluation of gelatin hydrogel as a potential carrier for cell transportation.

We prepared uncleaved gelatin composed mainly of collagen α-, β-, and γ-chains. Gelation and melting of uncleaved gelatin occurred rapidly with moderate decrease and increase in temperature (23°C-37°C). The viability of cells encapsulated in the gelatin gel was greater than 96% after 7 d at 23°C.

Temperature-responsive gelation of type I collagen solutions involving fibril formation and genipin crosslinking as a potential injectable hydrogel.

We investigated the temperature-responsive gelation of collagen/genipin solutions using pepsin-solubilized collagen (PSC) and acid-solubilized collagen (ASC) as substrates. Gelation occurred in the PSC/genipin solutions at genipin concentrations 0-2 mM under moderate change in temperature from 25 to 37°C. The PSC/genipin solutions exhibited fluidity at room temperature for at least 30 min, whereas the ASC/genipin solutions rapidly reached gel points.

Fabrication of high-density collagen fibril matrix gels by renaturation of triple-helix collagen from gelatin.

Collagen-based 3-D hydrogels often lack sufficient mechanical strength for tissue engineering. We developed a method for fabrication of high-density collagen fibril matrix (CFM) gels from concentrated solutions of uncleaved gelatin (UCG). Denatured random-coil UCG exhibited more rapid and efficient renaturation into collagen triple-helix than cleaved gelatin (CG) over a broad range of setting temperatures.

Fate of bone marrow mesenchymal stem cells following the allogeneic transplantation of cartilaginous aggregates into osteochondral defects of rabbits.

The purpose of this study was to track mesenchymal stem cells (MSCs) labelled with internalizing quantum dots (i-QDs) in the reparative tissues, following the allogeneic transplantation of three-dimensional (3D) cartilaginous aggregates into the osteochondral defects of rabbits. QDs were conjugated with a unique internalizing antibody against a heat shock protein-70 (hsp70) family stress chaperone, mortalin, which is upregulated and expressed on the surface of dividing cells. The i-QDs were added to the culture medium for 24 h.

Stable and nondisruptive in vitro/in vivo labeling of mesenchymal stem cells by internalizing quantum dots.

Progress in stem cell research has prioritized the refinement of cell-labeling techniques for in vitro and in vivo basic and therapeutic studies. Although quantum dots, because of their optical properties, are emerging as favorable nanoparticles for bioimaging, substantial refinements or modifications that would improve their biocompatibility are still required. We report here that internalizing quantum dots (i-QDs) generated by their conjugation with an internalizing antibody against a heat shock protein-70 family stress chaperone, mortalin, offered an efficient, genetically noninvasive, nontoxic, and functionally inert way to label mesenchymal stem cells (MSCs).

Rotating three-dimensional dynamic culture of adult human bone marrow-derived cells for tissue engineering of hyaline cartilage.

The method of constructing cartilage tissue from bone marrow-derived cells in vitro is considered a valuable technique for hyaline cartilage regenerative medicine. Using a rotating wall vessel (RWV) bioreactor developed in a NASA space experiment, we attempted to efficiently construct hyaline cartilage tissue from human bone marrow-derived cells without using a scaffold. Bone marrow aspirates were obtained from the iliac crest of nine patients during orthopedic operation.

Gene expression analysis of major lineage-defining factors in human bone marrow cells: effect of aging, gender, and age-related disorders.

Adult bone marrow cells (BMCs) include two populations:;mesenchymal stem cells (MSCs), which can differentiate into bone, cartilage, and fat; and hematopoietic stem cells (HSCs), which produce all mature blood lineage. To study the effect of aging, gender, and age-related disorders on lineage differentiation, we performed quantitative RT-PCR to examine mRNA expression of the major factors defining BMC lineage, cbfa1 for osteoblasts, ppar-gamma for adipocytes, sox9 for chondrocytes, and rankl for osteoclasts, in bone marrow from 80 healthy subjects and patients (14-79 years old) with two age-related disorders: osteoarthritis (OA) and rheumatoid arthritis (RA). Two apoptosis-related genes, bcl-2 and drak1, were studied.

Repair of large osteochondral defects with allogeneic cartilaginous aggregates formed from bone marrow-derived cells using RWV bioreactor.

Our objective was to examine the technique of regenerating cartilage tissue from bone marrow-derived cells by three-dimensional (3D) culture using the rotating wall vessel (RWV) bioreactor. Three-dimensional and cylindrical aggregates of allogeneic cartilage with dimensions of 10 x 5 mm (height x diameter) formed by the RWV bioreactor were transplanted into osteochondral defects of Japanese white rabbits (Group T, n = 15). For the control, some osteochondral defects were left empty (Group C, n = 18).

Cartilaginous tissue formation from bone marrow cells using rotating wall vessel (RWV) bioreactor.

This is the first successful report of the rapid regeneration of three-dimensional large and homogeneous cartilaginous tissue from rabbit bone marrow cells without a scaffold using a rotating wall vessel (RWV) bioreactor, which simulates a microgravity environment for cells. Bone marrow cells cultured for 3 weeks in DMEM were resuspended and cultured for 4 weeks in the chondrogenic medium within the vessel. Large cylindrical cartilaginous tissue with dimensions of (1.

Nanopillar sheets as a new type of cell culture dish: detailed study of HeLa cells cultured on nanopillar sheets.

Nanopillar sheets were fabricated with high-aspect ratio structures with a diameter of 160-1,000 nm and a height of 1 mum by nanoimprinting. The suitability of nanopillar sheets as a new type of cell culture dish was examined by studying the behavior of HeLa cells cultured on the sheets using light microscopy, scanning electron microscopy, and fluorescence microscopy observing actin and vinculin molecules. The nanopillar structure enabled easy subculture of the cells from the sheets without conventional trypsinization.