Hyalograft C: hyaluronan-based scaffolds in tissue-engineered cartilage.

Articular cartilage injuries have poor reparative capability and, if left untreated, may progress to osteo-arthritis. Unsatisfactory results with conventional treatment methods have prompted the development of innovative solutions including the use of cell transplantations, with or without a supporting scaffold. Tissue engineering combines cells, scaffolds and bio-active factors, which represents one of the most promising approaches for the restoration of damaged tissues.

Maturation of tissue engineered cartilage implanted in injured and osteoarthritic human knees.

The regeneration of damaged organs requires that engineered tissues mature when implanted at sites of injury or disease. We have used new analytic techniques to determine the extent of tissue regeneration after treatment of knee injury patients with a novel cartilage tissue engineering therapy and the effect of pre-existing osteoarthritis on the regeneration process. We treated 23 patients, with a mean age of 35.

Pharmacokinetic behaviour of ACP gel, an autocrosslinked hyaluronan derivative, after intraperitoneal administration.

Autocrosslinked polysaccharide (ACP) gel is a fully biocompatible cross-linked derivative of hyaluronic acid, which has prolonged in vivo residence time and improved mechanical properties with respect to native hyaluronan for use in various surgical applications. The objective of this study was to assess the pharmacokinetic behaviour of ACP gel in dogs after intraperitoneal administration. Seven beagle dogs received intraperitoneal injections of tritium-labelled ACP gel.

Hyaluronan-based scaffolds (Hyalograft C) in the treatment of knee cartilage defects: preliminary clinical findings.

Hyalograft C is an innovative tissue-engineering approach for the treatment of knee cartilage defects involving the implantation of laboratory expanded autologous chondrocytes grown on a three-dimensional hyaluronan-based scaffold. This technique has recently been introduced into clinical practice, with more than 600 patients treated so far. Because no periosteal coverage is required to keep the graft in place, surgical time and morbidity are reduced, and handling of the graft is much simpler than currently available autologous chondrocyte implantation techniques.

Aortic intimal thickening and myosin isoform expression in hyperthyroid rabbits.

The potential effect of thyroid hormones on the expression of cytoskeletal and cytocontractile proteins of vascular smooth muscle cells (SMCs) was examined by a panel of monoclonal antibodies and immunocytochemical procedures. L-Thyroxine was administered to adult New Zealand White rabbits for as long as 26 days, and the aortic SMC composition was studied at days 1, 2, 7, 15, and 26 from the beginning of hormonal treatment. A diffuse intimal thickening of the aorta became visible after 7 days of thyroxine administration.

A nifedipine-sensitive smooth muscle cell population is present in the atherosclerotic rabbit aorta.

We evaluated the ability of the Ca2+ channel blocker nifedipine to influence the severity of atherosclerotic lesions and the pattern of aortic smooth muscle cell (SMC) differentiation in cholesterol-fed New Zealand White rabbits. The animals were fed a 1% cholesterol-enriched diet for 12 weeks. After 4 weeks of the diet, some rabbits were given nifedipine (20 mg b.

Troponin T- and troponin I-like proteins in bovine vascular smooth muscle.

We have tested the hypothesis whether proteins with biochemical and immunochemical properties similar to those of troponin T (TnT) and troponin I (TnI) are expressed in bovine vascular smooth muscle (SM). Three monoclonal anti-TnT antibodies (TT-1, TT-2, and RV-C2) specific for the two isoforms of TnT present in the bovine cardiac muscle and two monoclonal antibodies (TI-1 and TI-5) reacting with cardiac TnI were used in this study. Anti-TnT antibodies were found to be unreactive with 1) skeletal and nonmuscle isoforms of glyceraldehyde-3-phosphate dehydrogenase, a glycolytic enzyme that shares some structural homologies with skeletal TnT, and 2) calponin, a TnT-like calmodulin/tropomyosin binding protein with some antigenic properties in common with TnT.

Myosin isoform expression and smooth muscle cell heterogeneity in normal and atherosclerotic rabbit aorta.

Two monoclonal antimyosin antibodies, Western blotting experiments, and immunofluorescence procedures were used to investigate myosin isoform expression in normal and atherosclerotic aortas of adult rabbits. The SM-E7 antibody reacted with the two myosin heavy chain (MHC) isoforms of smooth muscle (SM) type (SM-MHC-1 and SM-MHC-2) expressed in the adult rabbit aorta. The NM-G2 antibody recognized an epitope shared by the nonmuscle (NM) myosin heavy chains (NM-MHC) present in fibroblasts, macrophages, lymphocytes, and platelets.

Myosin isoforms and cell heterogeneity in vascular smooth muscle. I. Developing and adult bovine aorta.

Monoclonal anti-smooth muscle (SM-E7, SM-F11, and BF-48) and anti-nonmuscle (NM-A9 and NM-G2) myosin antibodies, Western blotting, and immunocytochemical procedures were used to study myosin isoform composition and distribution in the smooth muscle (SM) cells of bovine aorta differentiating in vivo and in vitro. Two myosin heavy chain (MHC) isoforms were identified by SM-E7 in adult aorta: SM-MHC-1 (Mr = 205 kDa) and SM-MHC-2 (Mr = 200 kDa), respectively. When tested with the SM-F11 antibody, SM-MHC-2 isoform showed distinct antigenic properties compared to SM-MHC-1.

Nonmuscle and smooth muscle myosin isoforms in bovine endothelial cells.

A panel of monoclonal antibodies, specific for human platelet (NM-A9, NM-F6, and NM-G2) and for bovine smooth muscle (SM-E7) myosin heavy chains (MHC), were used to study the composition and the distribution of myosin isoforms in bovine endothelial cells (EC), in vivo and in vitro. Using indirect and double immunofluorescence techniques, we have found that in the intact aortic endothelium there is expression of nonmuscle MHC (NM-MHC), exclusively. By contrast, hepatic sinusoidal endothelium as well as cultured bovine aortic EC (BAEC) in the subconfluent phase of growth show coexistence of NM- and smooth muscle MHC (SM-MHC) isoforms.

Myosin heavy-chain isoforms in adult and developing rabbit vascular smooth muscle.

Two monoclonal antibodies specific for smooth muscle myosin (designated SM-E7 and SM-A9) and one monoclonal anti-(human platelet myosin) antibody (designated NM-G2) have been used to study myosin heavy chain composition of smooth muscle cells in adult and in developing rabbit aorta. Sodium dodecyl sulfate/polyacrylamide gel electrophoresis and Western blotting experiments revealed that adult aortic muscle consisted of two myosin heavy chains (MCH) of smooth muscle type, named MHC-1 (205 kDa), and MHC-2 (200 kDa). In the fetal/neonatal stage of development, vascular smooth muscle was found to contain only MHC-1 but not MHC-2.

Myosin heavy-chain isoforms in human smooth muscle.

The myosin heavy-chain composition of human smooth muscle has been investigated by sodium dodecyl sulfate/polyacrylamide gel electrophoresis, enzyme immunoassay, and enzyme-immunoblotting procedures. A polyclonal and a monoclonal antibody specific for smooth muscle myosin heavy chains were used in this study. The two antibodies were unreactive with sarcomeric myosin heavy chains and with platelet myosin heavy chain on enzyme immunoassay and immunoblots, and stained smooth muscle cells but not non-muscle cells in cryosections and cultures processed for indirect immunofluorescence.

Neonatal myosin heavy chains are not expressed in Ni-induced rat rhabdomyosarcoma.

Myosin heavy chain (MHC) composition of chemically-induced rhabdomyosarcoma (RMS) was analyzed by gel electrophoresis and Western blotting using a panel of monoclonal antimyosin antibodies specific for embryonic-, neonatal-, slow- and adult fast-type MHC isoforms. Myosin extracted from tumours and electrophoresed on 6%-sodium dodecyl sulfate (SDS)glycerol gels was found to migrate as three distinct MHC components. These polypeptides were present in different relative amounts in the five RMS studied.