Development of Organogels for Live Yarrowia lipolytica Encapsulation

Zou

et al. 2022

In the field of thermal energy storage, organic phase change materials (PCMs) are widely used as functional materials to boost thermal applications. However, there is often a tradeoff between constructing shape-stable composite PCMs with high enthalpy value and those with low leakage rates. Here, we proposed a promising scheme to address this issue. A novel hydrogel consisting of reduced graphene oxide (rGO) and covalent organic framework (COF) was prepared via hydrothermal methods, and the rGO–COF ultralight aerogel with a hierarchical porous structure was formed after freeze-drying. The rGO–COF aerogel shows excellent absorption ability and affinity for organic solvents. It can sufficiently adsorb the molten organic PCMs, such as polyethylene glycol (PEG), and synthesize shape-stable composite PCMs with excellent leak resistance. The COF grown on the surface of rGO has a superior affinity for PEG, so rGO–COF aerogel shows an outstanding PEG loading rate of up to 96.1 wt %, which is 1.7 wt % higher than that of rGO aerogel. In addition, the COF effectively reduces the subcooling of PEG/rGO–COF with 20.3%, compared to PEG/rGO. Meanwhile, the prepared PEG/rGO–COF exhibits extremely high enthalpy and relative enthalpy efficiency (164.6 J/g, 97.4%). This demonstrates that a promising direction was highlighte for the preparation of high-enthalpy shape-stable composite organic PCMs in this work.

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Lipophilic Modified Hierarchical Multiporous rGO Aerogel-Based Organic Phase Change Materials for Effective Thermal Energy Storage

Zou

et al. 2022

“…Conductive hydrogels with three-dimensional (3D) networks can be applied as substrates of flexible electronic devices, such as smart energy storage equipment, wearable and portable sensors, and soft robots, because of their high flexibility and adjustable conductivities. − However, due to the inevitable freezing of the hydrogels and the sluggish electron and ion transport at low temperatures, , their ionic conductivity and flexibility reduce seriously, causing malfunction of the devices. Many efforts have been made to address this issue by weakening the hydrogen bonds between water molecules, − including the modification of polymer networks and the introduction of antifreezing agents (ionic liquids, etc.…”

Section: Introductionmentioning

confidence: 99%

Antifreezing, Antidrying, and Conductive Hydrogels for Electronic Skin Applications at Ultralow Temperatures

Quan,

Zhao,

Luo

et al. 2024

Although conductive hydrogel-based flexible electronic devices have superb flexibility and high conductivities, they tend to malfunction in dry or frigid areas. Herein, an ultralow-temperature tolerant, antidrying, and conductive composite hydrogel is designed for electronic skin applications on the basis of the synergy of double-crosslinked polymer networks, Hofmeister effect, and electrostatic interaction and fabricated by in situ free radical polymerization of 2-acrylamido-2methyl-1-propanesulfonic acid and acrylic acid in the presence of poly(vinyl alcohol) and conductive MXene sheets, followed by impregnation with LiCl. Thanks to the synergy of LiCl and the charged polar terminal groups of the synthesized polymers, the composite hydrogel can not only bear an ultralow temperature of −80 °C without freezing but also maintain its original mass. Meanwhile, the resultant hydrogel possesses satisfactory self-regeneration ability benefiting from the moisturizing effect of LiCl. The conductive network of MXene sheets greatly improves the ionic conductivity of the hydrogel at low temperatures, exhibiting an ionic conductivity of 1.4 S m −1 at −80 °C. Furthermore, the electronic skin assembled by the multifunctional hydrogel is efficient in monitoring human motions at −80 °C. The antifreezing and antidrying features along with favorable ionic conductivity, high tensile strength, and outstanding flexibility make the composite hydrogel promising for applications in frigid and dry regions.

“…Encapsulating EMC in hydrogels to form the "living material". The hydrogel encapsulation EMC has many advantages: first, the hydrogel could provide water, which is necessary for the EMC survival; 23 second, the hydrogel was able to avoid the potential inhibitory effect of the epidermal environment on the EMC; finally, hydrogel prevented engineered bacteria from escaping into the environment. 24 In this study, it was demonstrated that the sucrose-secreting engineered S. elongatus was able to support the growth of commonly used microbial chassis (Lactococcus lactis and Escherichia coli) in the EMC.…”

Section: ■ Introductionmentioning

confidence: 99%

“…Encapsulating EMC in hydrogels to form the “living material”. The hydrogel encapsulation EMC has many advantages: first, the hydrogel could provide water, which is necessary for the EMC survival; second, the hydrogel was able to avoid the potential inhibitory effect of the epidermal environment on the EMC; finally, hydrogel prevented engineered bacteria from escaping into the environment …”

Section: Introductionmentioning

confidence: 99%

Hydrogel-Encapsulated Engineered Microbial Consortium as a Photoautotrophic “Living Material” for Promoting Skin Wound Healing

Yang

et al. 2023

Genetically modified engineered microorganisms have been encapsulated in hydrogels and used as "living materials" for the treatment of skin diseases. However, their applications are often limited by the epidermal dry, nutrient-poor environment and cannot maintain functions stably for an expected sufficient time. To solve this problem, a photoautotrophic "living material" containing an engineered microbial consortium was designed and fabricated. The engineered microbial consortium comprised Synechococcus elongatus PCC7942 for producing sucrose by photosynthesis and another heterotrophic engineered bacterium (Escherichia coli or Lactococcus lactis) that can utilize sucrose for the growth and secretion of functional biomolecules. These engineered microorganisms in the "living material" were proved to function stably for a longer time than only individual microbes. Subsequently, CXCL12-secreting engineered L. lactis was used to construct the "living material", and its effect on promoting wound healing was verified in a full-thickness rat-skin defect model. The wounds treated by our hydrogel-encapsulated engineered microbial consortium (HeEMC) healed faster, with a wound area ratio of only 13.2% at day 14, compared to the remaining 62.6, 51.4, and 40.8% of the control, PEGDA, and PEGDA/CS groups, respectively. In conclusion, we established an efficient living material HeEMC to offer promising applications in the treatment of skin diseases.