Development of a Controlled Injection Method Using Support Templates for the Production of Chemobrionic Materials

Design of chemobrionic and biochemobrionic scaffolds for bone tissue engineering

Chemobrionic systems have attracted great attention in material science for development of novel biomimetic materials. This study aims to design a new bioactive material by integrating biosilica into chemobrionic structure, which will be called biochemobrionic, and to comparatively investigate the use of both chemobrionic and biochemobrionic materials as bone scaffolds. Biosilica, isolated from Amphora sp. diatom, was integrated into chemobrionic structure, and a comprehensive set of analysis was conducted to evaluate their morphological, chemical, mechanical, thermal, and biodegradation properties. Then, the effects of both scaffolds on cell biocompatibility and osteogenic differentiation capacity were assessed. Cells attached to the scaffolds, spread out, and covered the entire surface, indicating the absence of cytotoxicity. Biochemobrionic scaffold exhibited a higher level of mineralization and bone formation than the chemobrionic structure due to the osteogenic activity of biosilica. These results present a comprehensive and pioneering understanding of the potential of (bio)chemobrionics for bone regeneration.

Comparative Evaluation of Chemical Garden Growth Techniques

Chemical gardens are an exciting area of self-organized precipitation structures that form nano- and micro-sized structures in different shapes. This field has attracted great interest from researchers due to the specific characteristics and potential applications of these structures. Today, research on chemical gardens has provided deeper information regarding the formation mechanisms of these structures, and several techniques have been developed for chemical garden growth. However, they all show different growth patterns and lead to the formation of structures with a variety of morphological, chemical, or physical properties. This study aimed to evaluate the effects of different production techniques on chemical garden growth, taking into consideration the growth patterns, morphology, microstructure, and chemical composition. The chemical garden structures obtained in seed and injection experiments, two common methods, showed highly similar surface structures, void formation, and chemical composition. The membrane growth method has a small number of applications; thus, it was comprehensively evaluated to add new insights to the existing limited data. It produced the most stable and standard structures in a flat sheet-like shape and showed different morphologies than those observed in other two methods. Overall, this study presented significant results about the effect of growth techniques on chemical garden structures and similar systems.

Shape Evolution of Precipitate Membranes in Flow Systems

Chemical gardens are macroscopic structures that form when a salt seed is submerged in an alkaline solution. Their thin precipitate membranes separate the reactant partners and slow down the approach toward equilibrium. During this stage, a gradual thickening occurs, which is driven by steep cross-membrane gradients and governed by selective ion transport. We study these growth dynamics in microfluidic channels for the case of Ni(OH)₂ membranes. Fast flowing reactant solutions create thickening membranes of a nearly constant width along the channel, whereas slow flows produce wedge-shaped structures that fail to grow along their downstream end. The overall dynamics and shapes are caused by the competition of reactant consumption and transport replenishment. They are reproduced quantitatively by a two-variable reaction-diffusion-advection model which provides kinetic insights into the growth of precipitate membranes.