Evaluation of ethanol-induced chitosan aerogels with human osteoblast cells.

The following article provides an insight into the production of chitosan aerogels as potential materials for tissue engineering. Chitosan aerogels were prepared following two different protocols: formation in ethanol and formation in sodium hydroxide in an ethanol solution. The main objective was to apply a new route to obtain chitosan aerogels with no external cross-linkers and compare the mentioned preparation approaches. Forming chitosan aerogels in ethanol implies a simple, environmentally friendly, and efficient method. The prepared materials showed specific surface areas of up to 450 m2/g, highly porous networks and great mechanical properties. In vitro degradation studies revealed high stability for up to 10 weeks. The differences between the samples were significant. While the chitosan aerogels prepared in ethanol showed superior textural, morphological and mechanical properties, the chitosan aerogels prepared in the sodium hydroxide solution proved that a considerable influence on end properties could be made simply by adjusting the ageing medium. In vitro cell analysis with primary human osteoblasts showed good biocompatibility and pointed towards the potential use of these aerogels for orthopedic applications. This testing showed further that adjustments in structural properties by sodium hydroxide also come with a cost regarding their suitability to host bone cells.

Green Techniques for Preparation of Red Beetroot Extracts with Enhanced Biological Potential.

Red beetroot is well known for its high proportion of betalains, with great potential as functional food ingredients due to their health-promoting properties. The objective of this study was to investigate the influence of processing techniques such as Soxhlet, cold, ultrasound and supercritical fluid extraction on the betalains content and its antioxidant, anti-inflammatory and antihyperglycemic activities. Whilst Soxhlet extraction with water has provided the highest yield, the highest content of total phenolics was found in an extract prepared using Soxhlet extraction with 50% ethanol. Amongst eight phenolic compounds detected in the extracts, protocatechuic acid was the most abundant. The concentrations of total phenolics ranged from 12.09 mg/g (ultrasound extraction with 30% methanol) to 18.60 mg/g (Soxhlet extraction with 50% ethanol). The highest anti-inflammatory activity was observed for cold extraction with 50% methanol extract. The high radical scavenging activity of supercritical fluid extracts could be a consequence of nonphenolic compounds. The chemometrics approach was further used to analyse the results to find the "greenest" method for further possible application in the processing of beetroot in the food and/or pharmaceutical industry. According to the standard score, the best extraction method was determined to be Soxhlet extraction with 50% ethanol.