Liquid Metal-Doped Conductive Hydrogel for Construction of Multifunctional Sensors.

Interest in wearable and stretchable multifunctional sensors has grown rapidly in recent years. The sensing elements must accurately detect external stimuli to expand their applicability as sensors. However, the sensor's self-healing and adhesion to a target object have been major challenges in developing such practical and versatile devices. In this study, we prepared a hydrogel (LM-SA-PAA) composed of liquid metal (LM), sodium alginate (SA), and poly(acrylic acid) (PAA) with ultrastretchable, excellent self-healing, self-adhesive, and high-sensitivity sensing capabilities that enable the conformal contact between the sensor and skin even during dynamic movements. The excellent self-healing performance of the hydrogel stems from its double cross-linked networks, including physical and chemical cross-linked networks. The physical cross-link formed by the ionic interaction between the carboxyl groups of PAA and gallium ions provide the hydrogel with reversible autonomous repair properties, whereas the covalent bond provides the hydrogel with a stable and strong chemical network. Alginate forms a microgel shell around LM nanoparticles via the coordination of its carboxyl groups with Ga ions. In addition to offering exceptional colloidal stability, the alginate shell has sufficient polar groups, ensuring that the hydrogel adheres to diverse substrates. Based on the efficient electrical pathway provided by the LM, the hydrogel exhibited strain sensitivity and enabled the detection of various human motions and electrocardiographic monitoring. The preparation method is simple and versatile and can be used for the low-cost fabrication of multifunctional sensors, which have broad application prospects in human-machine interface compatibility and medical monitoring.

[Effect of Guben Zenggu Decoction on Expressions of Serum BALP and CaM, CaMKâ ¡ mRNA in NEI Network of Ovariectomized Rats].

OBJECTIVE: To observe the effect of Guben Zenggu Decoction on the expressions of calmodulin (CaM) and calcium/calmodulin-dependent protein kinase Ⅱ (CaMK Ⅱ) mRNA in the hypothalamus, pituitary, spleen, adrenal gland and femur in ovariectomized rats. To explore the mechanism of Guben Zenggu Decoction regulating and controlling osteoporosis through neuro-endocrine-immune (NEI) network. METHODS: The osteoporosis model was established by ovariectomy and randomly divided into model control group, Estradiol valerate group, Guben Zenggu Decoction high, medium and low concentration group. Selected the same age rats as the blank control group, after intervention, 10 rats were randomly selected at the time of 4th, 8th, 12th and 16th weeks from each group, After the success of the model and the successful intervention of Guben Zenggu Decoction for 4, 8, 12 and 16 weeks, the blood were taken from the heart, the serum bone alkaline phosphatase (BALP) levels was measured by the enzyme-linked immunosorbent assay (ELISA), and the thalamus, pituitary, spleen, adrenal, femoral tissue of rats were collected to detected the expressions of CaM and CaMKⅡ mRNA by using real-time fluorescence quantitative polymerase chain reaction (RT-PCR). RESULTS: At different time points (4 weeks, 8 weeks, 12 weeks, 16 weeks), the expressions of serum BALP and CaM and CaMKⅡ mRNA in NEI network in model group were significantly different from those in blank control group ( P<0.05). Compared with the model control group, serum BALP concentration and CaM mRNA expression in hypothalamus and pituitary tissue were significantly increased in estradiol valerate and Guben Zenggu Decoction groups ( P<0.05). However, the expression of CaM mRNA in adrenal gland, spleen and femur and the expression of CaMKⅡ mRNA in hypothalamus, pituitary, adrenal gland, spleen and femur were significantly decreased ( P<0.05); compared with estradiol valerate group, the effect of Guben Zenggu Decoction on the expressions of CaM mRNA and CaMKⅡ mRNA in femoral and adrenal tissues was significantly different ( P<0.05). CONCLUSION: Guben Zenggu Decoction can increase the serum concentration of BALP, regulate the expression of CaM mRNA and CaMKⅡ mRNA in hypothalamus, pituitary, adrenal gland, spleen and femur, thus play a role in prevention and treatment of osteoporosis by regulating NEI network.

Lecithin doped electrospun poly(lactic acid)-thermoplastic polyurethane fibers for hepatocyte viability improvement.

The development of hepatocyte cultures in vitro holds great significance in the study of bioartificial liver support systems. Electrospun fiber cultures have received widespread attention as an effective method to culture hepatocytes in vitro. Polylactic acid (PLA) -a synthetic polymer with high biocompatibility and biodegradability- is widely used to fabricate electrospun fibers in the biomedical field. However, the use of PLA is limited in cell cultures due to its brittleness, strong hydrophobicity, and lack of biologically active functional groups. In this study, thermoplastic polyurethane (TPU) and lecithin (Lec) were used to modify PLA by spiking them into the PLA electrospun solution in attempt to establish a suitable fiber scaffold for hepatocyte culture in bioreactors. TPU and lecithin incorporation into PLA increases the flexibility, hydrophilicity, and biologically active groups of the fibers which further promotes the growth, proliferation, and viability of hepatocytes. The morphology, wettability, and biocompatibility of the as-prepared PLA-TPU-Lec fibers were carefully characterized. The results showed that the PLA-TPU-Lec fibers possessed favorable morphology and hydrophilicity, as well as high biocompatibility ability. HepG2 cells on the PLA-TPU-Lec fibers and tissue culture plates (TCP) were exposed to hepatotoxins for 24 h and we found that HepG2 cells on the PLA-TPU-Lec fibers had higher viability than cells on TCP. The PLA-TPU-Lec fibers are therefore expected to be used in vitro for hepatocyte culture to improve cellular activity in artificial liver bioreactors.