Calf articular cartilage in organ culture in a chemically defined medium

In Vitro Cellular &; Developmental Biology - Plant - Articular cartilage from 6-month-old calves was maintained in organ culture in Eagle's minimum essential medium at different oxygen...     

Calf anticular cartilage in organ culture in a chemically defined medium. I. Autoradiographic study after [35S]sulfate labeling.

Articular cartilage from 5-month-old calves survived for 4 weeks in organ culture in a chemically defined medium. The viability was assessed by calculating the labeling frequency of chondrocytes on autoradiograms after [35S]sulfate labeling. The survival rate of chondrocytes was highest in 20% oxygen tension, whereas 50% oxygen resulted in chondrocyte death after 2 weeks. The survival rate was improved by using 1-mm thick standardized pieces of cartilage. The cells of the superficial layer showed a higher proportion of living chondrocytes than the cells in the deeper layers. No differentiation, dedifferentiation, or outgrowth of cells occurred during the experimental period.     

A case study on stress preconditioning of a Lactobacillus strain prior to freeze-drying

Freeze-drying of bacterial cells with retained viability and activity after storage requires appropriate formulation, i.e. mixing of physiologically adapted cell populations with suitable protective agents, and control of the freeze-drying process. Product manufacturing may alter the clinical effects of probiotics and it is essential to identify and understand possible factor co-dependencies during manufacturing. The physical solid-state behavior of the formulation and the freeze-drying parameters are critical for bacterial survival and thus process optimization is important, independent of strain. However, the maximum yield achievable is also strain-specific and strain survival is governed by e.g. medium, cell type, physiological state, excipients used, and process. The use of preferred compatible solutes for cross-protection of Lactobacilli during industrial manufacturing may be a natural step to introduce robustness, but knowledge is lacking on how compatible solutes, such as betaine, influence formulation properties and cell survival. This study characterized betaine formulations, with and without sucrose, and tested these with the model lactic acid bacteria Lactobacillus coryniformis Si3. Betaine alone did not act as a lyo-protectant and thus betaine import prior to freeze-drying should be avoided. Differences in protective agents were analyzed by calorimetry, which proved to be a suitable tool for evaluating the characteristics of the freeze-dried end products.