Zusammenfassung
Zellbasierte therapeutische Ansätze werden bereits erfolgreich angewandt und gewinnen zunehmend an Bedeutung bei der Behandlung von Gelenkerkrankungen. Mesenchymale Stamm- und ...Vorläuferzellen besitzen ein vielfältiges Repertoire an Eigenschaften, die sich optimal zur Regeneration von Knochen- und Knorpelschäden nutzen lassen.
Welche Eigenschaften dies im Einzelnen sind und wie sie zur Verbesserung bestehender Techniken beitragen oder in neuen Strategien genutzt werden können, wird im Folgenden diskutiert.
Hydroxyapatite chromatography is shown to be an excellent method for chromatographically purifying monoclonal antibodies (Mab). Mab contained in eluates from Protein A columns was partially purified ...on ceramic hydroxyapatite (CHT™) Type I, 40 μm ceramic hydroxyapatite using two scouting methods which provide milligram amounts of Mab typical at laboratory scale. The result from one of the scouting methods was optimized to obtain a high concentration of purified Mab with acceptable clearance of cell culture impurities. Several techniques (linear phosphate screening, linear alkaline salt screening, and two alkaline salt step gradients) are described for obtaining high concentrations of purified Mab in a lab-scale CHT chromatography column.
Regeneration therapy can be classified into three categories. The first category, in vitro regeneration therapy, makes use of transplanted cultured cells, including embryonic stem (ES) cells, ...pancreatic precursor cells and beta-cell lines, in conjunction with immunosuppressive therapy or immunoisolation for the treatment of patients with Type 1 diabetes. In the second type of regeneration therapy, ex vivo regeneration therapy, a patient's own cells, such as bone marrow stem cells, are transiently removed and induced to differentiate into beta-cells in vitro. However, at the present time, insulin-producing cells cannot be generated from bone marrow stem cells. In vivo regeneration therapy, the third type of regeneration therapy, enables impaired tissue to regenerate from a patient's own cells in vivo. beta-Cell neogenesis from non-beta-cells, and beta-cell proliferation in vivo have been considered in particular as regeneration therapies for patients with Type 2 diabetes. Regeneration therapy for pancreatic beta-cells can be combined with various other therapeutic strategies, including islet transplantation, cell-based therapy, gene therapy and drug therapy, to promote beta-cell proliferation and neogenesis; it is hoped that these strategies will, in the future, provide a cure for diabetes.
An
in situ regeneration system for rice calli comprised of a callus growth stage and two regeneration stages was developed. After the first stage of regeneration, the medium is changed and the calli ...are immobilized in polyurethane foam supports, in each of which 3–5 regenerated plantlets develop from the immobilized calli during the second stage. While no significant change in callus size was observed during the first stage of regeneration, in the second stage callus enlargement and shoot regeneration predominated. In the light of these findings, calli were immobilized in the second stage after medium exchange. The use of 10-mm support cubes with an average pore size of 3.6 mm resulted in the most efficient immobilization and
in situ regeneration. Medium exchange after 15 d gave the largest number of support cubes with shoots. When rice calli were cultivated in support cubes placed in 60 ml second-stage medium in a 500-ml flask, the immobilization ratio was 83%, and 82% of the support cubes contained 3–5 regenerated plantlets after 25 d. The shoot lengths of the regenerated plantlets obtained from the
in situ regeneration culture were longer than those from a suspension culture. When support cubes with 3–5 regenerated plantlets were transferred from the flask to
1
4
MS solid medium supplemented with 10 g/
l sorbitol and 5 g/
l sucrose, the regenerated plantlets developed quickly into plants with a length above 10 cm after 10 d.
Zusammenfassung
Therapeutische Ansätze der Regenerativen Medizin lassen sich, unabhängig vom Fachgebiet, der Zelltherapie, dem Tissue Engineering und der In-situ-Regeneration zuordnen. Dabei kommt ...der Regenerativen Orthopädie oft eine Vorreiterrolle auf dem Weg zur klinischen Anwendung zu. In der Zelltherapie sollen primäre Zellen durch adulte mesenchymale Stammzellen mit nahezu unbegrenzter Regenerationskapazität ersetzt werden; eine ausgereiftere Strukturgebung von Biomaterialien ermöglicht im Tissue Engineering die gezielte Steuerung von Zellform und Gewebeaufbau, bei der In-situ-Regeneration steht die gezielte Vermittlung von Informationen an Zellen über intelligente Biomaterialien im Mittelpunkt der Forschung. Diese neuen Ansätze werden es möglich machen, bei der Wiederherstellung von Strukturen und Funktionen beschädigter oder dysfunktionaler Gewebe immer häufiger eine nachhaltige Verbesserung im Sinne einer echten Regeneration anstelle einer akzeptablen Reparatur zu erzielen.
