In vitro and in vivo evaluation of chitosan-gelatin scaffolds for cartilage tissue engineering.

Chitosan-gelatin polyelectrolyte complexes were fabricated and evaluated as tissue engineering scaffolds for cartilage regeneration in vitro and in vivo. The crosslinker for the gelatin component was selected among glutaraldehyde, bisepoxy, and a water-soluble carbodiimide (WSC) based upon the proliferation of chondrocytes on the crosslinked gelatin. WSC was found to be the most suitable crosslinker.

Bioengineered periosteal progenitor cell sheets to enhance tendon-bone healing in a bone tunnel.

Background: Tendon-bone tunnel healing is crucial for long term success in anterior cruciate ligament (ACL) reconstruction. The periosteum contains osteochondral progenitor cells that can differentiate into osteoblasts and chondroblasts during tendon-bone healing. We developed a scaffold-free method using polymerized fibrin-coated dishes to make functional periosteal progenitor cell (PPC) sheets.

Effect of hyperbaric oxygenation on intervertebral disc degeneration: an in vivo study with sprague-dawley rats.

Study Design: An in vivo study was conducted to test the effect of hyperbaric oxygenation (HBO) on intervertebral disc degeneration in Sprague-Dawley rats.

Objective: To observe the changes in intervertebral disc height and levels of glycosaminoglycan, collagen, interleukin-1β (IL-1β), prostaglandin E2 (PGE2), and inducible nitric oxide synthase (iNOS) in degenerated intervertebral discs after HBO therapy.

Summary Of Background Data: Although the involvement of IL-1β, PGE-2, NO, and low O2 concentration has been demonstrated in intervertebral disc degeneration, the actual mechanism is not clear.

Bone marrow mesenchymal stem cells, platelet-rich plasma and nanohydroxyapatite-type I collagen beads were integral parts of biomimetic bone substitutes for bone regeneration.

Platelet rich plasma (PRP), which includes many growth factors, can activate osteoid production, collagen synthesis and cell proliferation. Nanohydroxyapatite-type I collagen beads (CIB), which mimetic natural bone components, are not only flexible fillers for bone defect but also encourage osteogenesis. Bone marrow mesenchymal stem cells (BMSCs) are often used as an abundant cell source for tissue engineering.

Enhancement of rotator cuff tendon-bone healing with injectable periosteum progenitor cells-BMP-2 hydrogel in vivo.

Purpose: The fixation and incorporation of ruptured rotator cuff tendon to bone is a major concern in rotator cuff repair surgery. Rotator cuff repair usually fails at the tendon-bone interface, especially in case of large or massive tears. To enhance tendon-bone healing, an injectable hydrogel made with periosteal progenitor cells(PPCs) and poly (ethylene glycol) diacrylate (PEGDA) tethered with bone morphogenic protein-2(BMP-2) was developed to encourage extracellular matrix synthesis for tendon-to-bone healing in rotator cuff repair.

The effect of ultrasound stimulation versus bioreactors on neocartilage formation in tissue engineering scaffolds seeded with human chondrocytes in vitro.

Pulsed ultrasound (1 MHz, 67 mW/cm(2) Ispta, and 10 min/day) promoted cell proliferation and matrix deposition in low-density 2D ( approximately 6 x 10(3)cells/cm(2)) as well as 3D ( approximately 4 x 10(6)cells/cm(3)) chondrocyte cultures. The beneficial effect of ultrasound on neocartilage formation only last 28 days, shorter than that of bioreactors.

Evaluation of biodegradable polyesters modified by type II collagen and Arg-Gly-Asp as tissue engineering scaffolding materials for cartilage regeneration.

Synthetic biodegradable polyesters poly(L-lactide) (PLLA) and poly(D,L-lactide-coglycolide) (PLGA) (50:50) modified by porcine type II collagen and an Arg-Gly-Asp (RGD)-containing protein were evaluated as scaffolds for cartilage regeneration in this study. Cytocompatibility of the polymer films was tested using immortalized chondrocytes. Neocartilage formation in vitro on cell-seeded scaffolds was further examined using primary porcine chondrocytes.

The effect of two different bioreactors on the neocartilage formation in type II collagen modified polyester scaffolds seeded with chondrocytes.

The effect of dynamic culture conditions on neocartilage formation in type II collagen modified polyester scaffolds was studied. Porcine or human articular chondrocytes were seeded in the scaffolds. The cell-scaffold constructs were cultivated statically, in a rotating-type bioreactor or in a shaker for up to 4 weeks.

Evaluation of chitosan-alginate-hyaluronate complexes modified by an RGD-containing protein as tissue-engineering scaffolds for cartilage regeneration.

In this study, a series of natural biodegradable materials in the form of chitosan (C)-alginate (A)-hyaluronate (H) complexes are evaluated as tissue-engineering scaffolds. The weight ratio of C/A is 1 : 1 or 1 : 2. Sodium hyaluronate is mixed in 2%.