Rediscovering Chemical Gardens: Self-Assembling Cytocompatible Protein-Intercalated Silicate–Phosphate Sponge-Mimetic Tubules

The classic chemical garden experiment is reconstructed to produce protein-intercalated silicate–phosphate tubules that resemble tubular sponges. The constructs were synthesized by seeding calcium chloride into a solution of sodium silicate–potassium phosphate and gelatin. Sponge-mimetic tubules were fabricated with varying percentages of gelatin (0–15% w/v), in diameters ranging from 200 μm to 2 mm, characterized morphologically and compositionally, functionalized with biomolecules for cell adhesion, and evaluated for cytocompatibility. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy analysis (EDS) experiments showed that the external surface of the tubules was relatively more amorphous in texture and carbon/protein-rich in comparison to the interior surface. Transmission electron microscopy (TEM) images indicate a network composed of gelatin incorporated into the inorganic scaffold. The presence of gelatin in the constructs was confirmed by infrared spectroscopy. Powder X-ray...