sepharose and Wounds-and-Injuries

Materials can be made multifunctional by embedding them with living cells that perform sensing, synthesis, energy production, and physical movement. A challenge is that the conditions needed for living cells are not conducive to materials processing and require continuous water and nutrients. Here, we present a three dimensional (3D) printer that can mix material and cell streams to build 3D objects. Bacillus subtilis spores were printed within the material and germinated on its exterior surface, including spontaneously in new cracks. The material was resilient to extreme stresses, including desiccation, solvents, osmolarity, pH, ultraviolet light, and γ-radiation. Genetic engineering enabled the bacteria to respond to stimuli or produce chemicals on demand. As a demonstration, we printed custom-shaped hydrogels containing bacteria that can sense or kill Staphylococcus aureus, a causative agent of infections. This work demonstrates materials endued with living functions that can be used in applications that require storage or exposure to environmental stresses.

Topics: Anti-Bacterial Agents; Bacillus subtilis; Bacterial Physiological Phenomena; Equipment Design; Escherichia coli; Hydrogen-Ion Concentration; Materials Testing; Microorganisms, Genetically-Modified; Printing, Three-Dimensional; Quorum Sensing; Sepharose; Spores, Bacterial; Staphylococcus aureus; Stress, Physiological; Temperature; Vanillic Acid; Wounds and Injuries

To meet the progressive requirements of advanced engineering materials with superior physicochemical performances, self-healing and injectable hydrogels (AD hydrogels) based on agarose with pH-response were prepared through dynamic covalent Schiff-base linkages by simply mixing nontoxic agarose-ethylenediamine conjugate (AG-NH

Topics: Bandages; Human Umbilical Vein Endothelial Cells; Humans; Hydrogels; Sepharose; Tissue Adhesives; Wounds and Injuries

In this paper, a kind of skin dressing, agarose- grafting- hyaluronic acid (Ag-g-HA) sponge was applied to test the modified agarose based scaffold for skin regeneration. The bFGF loading agarose-grafting hyaluronan scaffold had homogenous porosities, and the loaded bFGF was bioactive in 2 weeks. The Ag-g-HA sponge was applied into skin of mice, and it was found that the dressing promoted skin regeneration and no infection and leakage in lesion site took place. H&E staining results showed that the repaired skin was similar to autologous skin. These demonstrate that Ag-g-HA sponge has a promise in skin regeneration.

Topics: Animals; Bandages; Female; Fibroblast Growth Factor 2; Hyaluronic Acid; Mice; Mice, Inbred C57BL; Polysaccharides; Random Allocation; Seaweed; Sepharose; Surgical Sponges; Wound Healing; Wounds and Injuries