Ternary mixtures of ionic liquids for better salt solubility, conductivity and cation transference number improvement.

We hereby present the new class of ionic liquid systems in which lithium salt is introduced into the solution as a lithium cation-glyme solvate. This modification leads to the reorganisation of solution structure, which entails release of free mobile lithium cation solvate and hence leads to the significant enhancement of ionic conductivity and lithium cation transference numbers. This new approach in composing electrolytes also enables even three-fold increase of salt concentration in ionic liquids.

Dielectric study of interaction of water with normal and osteoarthritis femoral condyle cartilage.

The main goal of this paper is the in vitro study of healthy and osteoarthritis (OA) human cartilage using the dielectric spectroscopy in the alpha-dispersion region of the electric field and in the temperatures from 25 to 140°C. The activation energy of conductivity needed to break the bonds formed by water in the extracellular matrix takes the average values of 61kJ/mol and 44kJ/mol for the control and OA cartilages, respectively. At 28°C, the small difference appears in the permittivity decrement between the control and OA cartilages, while the conductivity increment is about 2 times higher for the control tissue than that for the OA tissue. At 75°C, the conductivity increment for both of these samples is 8 times higher than their respective permittivity decrement. In addition, at 140°C the values of these both parameters for the OA tissue decrease by 8 times as compared to those recorded for the control sample. The relaxation frequency of about 10kHz is similar for both of these samples. The knowledge on dielectric properties of healthy and OA cartilage may prove relevant to tissue engineering focused on the repair of cartilage lesions via the layered structure designing.

Evaluation of cartilage reconstruction by means of autologous chondrocyte versus periosteal graft transplantation: an animal study.

BACKGROUND: Autologous chondrocyte transplantation (ACT) has been shown to heal cartilage defects under experimental and clinical conditions. However, the evaluation of successful transplantation still remains arbitrary and further research is required to establish objective criteria of treatment. The aim of the present study was to evaluate the criteria of successful ACT and to compare the results with those obtained following periosteal grafting (PG). MATERIALS AND METHODS: Articular cartilage specimens were taken from the distal femur of 30 adolescent New Zealand rabbits and chondrocytes were obtained by collagenase digestion. The chondrocytes were identified by a functional assay, based on estimating procollagen type II mRNA by reverse-transcribed polymerase chain reaction. The cells cultured in vitro were transplanted under a periosteal flap into a full thickness defect (ICRS III(0)). The quality of the repaired tissue was evaluated macroscopically according to a modified scale of Brittberg et al, and microscopically according to O'Driscoll et al. For comparative purposes animals treated with PG were used. RESULTS: Cultured chondrocytes expressed procollagen type II and, upon transplantation into the defect, produced hyaline cartilage. To evaluate the results of transplantation, two categories of criteria were adopted-macroscopic analysis and microscopic examination. By all adopted criteria the results were significantly better in the ACT group (P < .05) than in the PG group. CONCLUSION: Prior to transplantation, assays for specialized functions of chondrocytes required semiquantitative evaluation of macroscopic and microscopic appearance of the repaired tissue, showing the benefit of autologous chondrocyte versus periosteal graft transplantation.

Articular cartilage repair by means of biodegradable scaffolds.

INTRODUCTION: Articular cartilage has a limited capacity for self-repair; untreated injuries of cartilage may lead to osteoarthritis. In severe cases the only choice a total joint replacement, may be inadequate in young patients. This problem demands new effective methods to reconstruct articular cartilage. The aim of this study was to evaluate the application of collagen matrix for the reconstruction of articular cartilage. MATERIALS AND METHODS: A group of 28 rabbits had a defect penetrating into the subchondral constructed and either filled with collagen scaffold (group I) or remained empty (group II). The results were observed after 4 and 12 weeks. Macroscopic and microscopic evaluations were performed. RESULTS: In the first group we observed the presence of hyalinelike cartilage resembling normal articular cartilage. In the second group fibrous tissue dominated. The surface of regenerated tissue was smooth, intact, and the defect completely filled with regenerated tissue, showing good structural integrity. In the second group, superficial irregularities, disorders of structural integrity, and necrotic features were noticed. CONCLUSIONS: This study showed better results of articular cartilage reconstruction by means of a biodegradable scaffold.

The experimental reconstruction of articular cartilage using autogenous periosteal and perichondreal implants.

Injured cartilage has a limited capacity to heal itself. Untreated damage leads to secondary osteoarthritis. There is a need to find a way to reconstruct cartilage in order to prevent secondary osteoarthritis. The aim this study was to evaluate and compare the chondrogenic potential of three different cell materials: perichonrdrial grafts, periosteal grafts and bone marrow in situ. The mesenchemal cells contained in these materials can differentiate in the joint environment into chondrocytes and rebuild articular cartilage.
Forty nine (49) White New Zealand rabbits were used in our experiment. An osteochondrial (full-thickness) defect was created in the joint surface of both ends of the femoral bone. The animals were divided according to the procedure used:
I - cartilage reconstruction by periosteal grat,
II - cartilage reconstruction by perichondrial graft,
III - no graft.
The joint was not immobilized after surgery. Follow-up exams were performed at 4, 8, and 12 weeks. The results were evaluated macroscopically and microscopically.
The results pointed to the chondrogenic potential of periosteum and perichondrium after grafting to cartilage defects. On gross examination the articular surface was found to be reconstructed. Microscopic examination revealed regeneration, with the formation of hyaline-like cartilage. Regenerating tissue was also found in the group without grafts. The structure resembled normal articular cartilage; however, neither the joint surface nor the subchondrial bone were fully reconstructed. No qualitative or quantitative differences were found between the groups treated with periosteal and perichondral grafts.
Our study confirmed that grafts of periosteum or perichondrium have chondrogenic potential, i.e. the ability to generate cartilage tissue whose features are similar to those of the hyaline chondrial tissue in the joint. Both materials have similar chondrogenic potential. The chondrogenic properties of perichondrium and perisostem produce better results in the various categories in comparison to those of bone marrow.

The reconstruction of defects in articular cartilage using autologous chondrocytes.

A defect was artificially created on the joint surface of the distal ends of both femoral bones in 30 rabbits. After digestion of the cartilage fragment, the resulting cells were cultured in vitro and multiplied. The multiplied autologous chondrocytes were implanted at the point of the defect under a periosteum patch in the right knee (group I). The defect in the left knee was covered with periosteum alone (group II). The regenerates obtained in this way were evaluated at 4, 8, and 12 weeks after surgery, macroscopically for even coverage of the surface of the defect and the quantity of regenerate in proportion to the surrounding healthy tissue, microscopically with H + E stain for the nature of the prevalent tissue, integration with the environment, the presence of necrosis, the formation of isogenous groups of cells, and the formation of cracks.
In the macroscopic evaluations at weeks 4, 8, and 12, the presence of regenerate was discovered in group I in approximately the same quantities as in the surrounding cartilage. The group II joints were found to have less satisfactory repair of the lesion.
In the microscopic evaluation, group I was found histologically to have cartilage tissue well integrated with the environment and chondrocytes forming isogenous groups of cells. In group II most of the joints were found to have incomplete or no integration with the surrounding tissue, with necrosis and cracking.
The reconstruction of defects in articular cartilage using autologous chondrocytes and periosteum produced a regenerate macroscopically similar to the surrounding articular cartilage. The results obtained by regeneration of articular cartilage using autologous chondrocyte grafts and periosteum were superior to those obtained with isolated periosteum grafts.

[The possibility of isolation, culture and storage of articular cartilage cells]. / Mozliwosc izolacji, hodowli i przechowywania komórek chrzastki stawowej.

Lesions of articular cartilage are a common problem and concern millions of people world-wide. A decrease in physical activity and pain symptoms among patients resulting from damage to articular cartilage have prompted research concerning new methods allowing cartilage regeneration. State-of-the-art treatment of articular damage depends very much on genetic engineering techniques. The aim of this paper was to determine the authors' own way of isolation, proliferation and storage of chondrocytes of articular cartilage. The material consisted of 30 rabbits, from which fragments of articular cartilage were taken. The study consisted of the following stages: isolation, chondrocyte proliferation, cell and matrix identification, storage and MTT tests. Matrix digestion was achieved using the following solutions: 0.1% type IA collagenase; 0.025% trypsin, a mixture of collagenase and trypsin. The greatest amount of cells were found after digestion of the basic matter of cartilage by 0.1% solution of type IA collagenase. When ascorbic acid was added to the medium, a 25% increase in cellularity was observed. A cumulation of procollagen mRNA was noted in the isolated cells. After about 21 days the isolated cells formed a multilayer structure, with the space between the cells filled with a substance that showed typical traits for cartilage matrix. Storing the isolated cells for less than 48 hours at room temperature gave a 90% survival rate. Most cells died after less than 12 hours when stored at 4 degrees C. The described method of chondrocyte isolation proved to be effective in preparing material for treatment of articular cartilage lesion.

[Analysis of angiotensin converting enzyme (ACE) polymorphism in patients with myocardial infarction in the Polish population]. / Analiza polimorfizmu Genu knowertazy angiotensynowej (ACE) u chorych z przebytym zawalem miesnia sercowego w populacji polskiej.

Analysis is presented of polymorphism of gene specifying angiotensin converting enzyme in Polish population and its comparison with results obtained for control group. Insertion/deletion polymorphism was detected by polymerase chain reaction. Frequencies of I/D alleles in control group were similar to those reported in French population but different frequencies were observed in patients with myocardial infarction.