Texture analysis of TEM micrographs of alginate gels for cell microencapsulation

Influence of surfactants and proteins on the properties of wet edible calcium alginate meat coatings

Calcium alginate structures are of interest as replacers for natural casings due to their high availability, biodegradability and low price. The aim of this paper is to study the effect of oil, surfactants and proteins (pea and collagen) on the water transfer, mechanical and microstructural properties of the wet calcium alginate films. The addition of oil and surfactants tended to reduce the water permeance and the weight loss rate, reaching values between those shown by natural and collagen artificial casings. The addition of proteins did not improve the adherence of the films and it decreased the maximum force of the film at puncture test, which was even lower with the presence of the surfactant E475. The TEM micrographs showed that the differences in mechanical properties are mainly related to the differences in the compaction of the microstructure. Wet alginate films with E475 are envisaged as a substitute of natural and collagen artificial casings in the stuffed meat products industry.

On the Correlation between the Microscopic Structure and Properties of Phosphate-Cross-Linked Chitosan Gels

Ionic chitosan gels fabricated using multivalent anions, tripolyphosphate (TPP) or pyrophosphate (PPi), respectively, have been investigated as potential biomaterials to be used in tissue engineering. Starting from the hypothesis that the polymer mesh texture at the microscale affects the final performance of the resulting materials, an innovative image analysis approach is presented in the first part of the article, which is aimed at deriving quantitative information from transmission electron microscopy images. The image analysis of the (more extended) central area of the gel networks revealed differences between both the cross-linking densities and pore size distributions of the two systems, the TPP gels showing a higher connectivity. Chitosan-TPP gels showed a limited degradation in simulated physiological media up to 6 weeks, reasonably ascribed to the texture of the (more extended) central area of the gels, whereas PPi counterparts degraded almost immediately. The release profiles and the calculation of diffusion coefficients for bovine serum albumin and cytochrome c, herein used as model payloads, indicated a different release behavior depending on the polymer network homogeneity/inhomogeneity and molecular weight of loaded molecules. This finding was ascribed to the marked inhomogeneity of the PPi gels (at variance with the TPP ones), which had been demonstrated in our previous work. Finally, thorough in vitro studies demonstrated good biocompatibility of both chitosan gels, and because of this feature, they can be used as suitable scaffolds for cellular colonization and metabolic activity.

Recent advances in morphological cell image analysis

This paper summarizes the recent advances in image processing methods for morphological cell analysis. The topic of morphological analysis has received much attention with the increasing demands in both bioinformatics and biomedical applications. Among many factors that affect the diagnosis of a disease, morphological cell analysis and statistics have made great contributions to results and effects for a doctor. Morphological cell analysis finds the cellar shape, cellar regularity, classification, statistics, diagnosis, and so forth. In the last 20 years, about 1000 publications have reported the use of morphological cell analysis in biomedical research. Relevant solutions encompass a rather wide application area, such as cell clumps segmentation, morphological characteristics extraction, 3D reconstruction, abnormal cells identification, and statistical analysis. These reports are summarized in this paper to enable easy referral to suitable methods for practical solutions. Representative contributions and future research trends are also addressed.