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Structure changes mediated by anisotropic volume changes of stimuli‐responsive hydrogels are useful for many research fields, yet relatively simple structured objects are mostly used due to limitation in fabrication methods. To fabricate complex 3 dimensional (3D) structures that undergo structure changes in response to external stimuli, jammed microgel‐based inks containing precursors of stimuli‐responsive hydrogels are developed for extrusion‐based 3D printing. Specifically, the jammed microgel‐based inks are prepared by absorbing precursors of poly(acrylic acid) or poly(N‐isopropylacrylamide) in poly(acrylamide) (PAAm) microgels, and jamming them. The inks exhibit shear‐thinning and self‐healing properties that allow extrusion of the inks through a nozzle and rapid stabilization after printing. Stimuli‐mediated volume changes are observed for the extruded structures when they are post‐crosslinked by UV light to form interpenetrating networks of PAAm microgels and stimuli‐responsive hydrogels. Using this method, a dumbbell‐shaped object that can transform to a biconvex shape, and a gripper that can grasp and lift an object in response to stimuli are 3D‐printed. The jammed microgel‐based 3D printing strategy is a versatile method useful for variety of applications as diverse types of monomers absorbable in the microgels can be used to fabricate complex 3D objects transformable by external stimuli. [ABSTRACT FROM AUTHOR]

Abstract: 3D‐printing is emerging as a technology to introduce microchannels into hydrogels, for the perfusion of engineered constructs. Although numerous techniques have been developed, new techniques are still needed to obtain the complex geometries of blood vessels and with materials that permit desired cellular responses. Here, a printing process where a shear‐thinning and self‐healing hydrogel “ink” is injected directly into a “support” hydrogel with similar properties is reported. The support hydrogel is further engineered to undergo stabilization through a thiol‐ene reaction, permitting (i) the washing of the ink to produce microchannels and (ii) tunable properties depending on the crosslinker design. When adhesive peptides are included in the support hydrogel, endothelial cells form confluent monolayers within the channels, across a range of printed configurations (e.g., straight, stenosis, spiral). When protease‐degradable crosslinkers are used for the support hydrogel and gradients of angiogenic factors are introduced, endothelial cells sprout into the support hydrogel in the direction of the gradient. This printing approach is used to investigate the influence of channel curvature on angiogenic sprouting and increased sprouting is observed at curved locations. Ultimately, this technique can be used for a range of biomedical applications, from engineering vascularized tissue constructs to modeling in vitro cultures. [ABSTRACT FROM AUTHOR]

Scutellaria baicalensis has been extensively employed for the clinical treatment of hyperlipidemia, atherosclerosis, hypertension, dysentery, inflammatory diseases, and the common cold. The present study was performed to investigate the anti-obesity and anti-dyslipidemia effect of Scutellaria baicalensis extracts (SBE) in type 2 diabetic db/db mice. Male db/db mice were divided into three groups ( n = 5) and orally administrated vehicle (control), SBE 10, and 100 mg/kg body weight/day for 4 weeks everyday. Administration of SBE improves weight gain, hypertriglyceridemia, and hyperinsulinemia in db/db mice. In obese db/db mice, SBE treatment also reduced plasma alanine aminotransferase levels. In the livers of db/db mice, SBE promoted 5' AMP-activated protein kinase activity and restored metabolic process and insulin signaling pathways. Our data demonstrate that SBE exerts potent anti-obesity and anti-hypertriglyceride effects suggesting its useful potential function as adjuvant therapeutic agent for the treatment of weight gain and hypertriglyceridemia. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Conductive hydrogels are attractive to mimic electrophysiological environments of biological tissues and toward therapeutic applications. Injectable and conductive hydrogels are of particular interest for applications in 3D printing or for direct injection into tissues; however, current approaches to add conductivity to hydrogels are insufficient, leading to poor gelation, brittle properties, or insufficient conductivity. Here, an approach is developed using the jamming of microgels to form injectable granular hydrogels, where i) hydrogel microparticles (i.e., microgels) are formed with water‐in‐oil emulsions on microfluidics, ii) microgels are modified via an in situ metal reduction process, and iii) the microgels are jammed into a solid, permitting easy extrusion from a syringe. Due to the presence of metal nanoparticles at the jammed interface with high surface area in this unique design, the granular hydrogels have greater conductivity than non‐particle (i.e., bulk) hydrogels treated similarly or granular hydrogels either without metal nanoparticles or containing encapsulated nanoparticles. The conductivity of the granular hydrogels is easily modified through mixing conductive and non‐conductive microgels during fabrication and they can be applied to the 3D printing of lattices and to bridge muscle defects. The versatility of this conductive granular hydrogel will permit numerous applications where conductive materials are needed. [ABSTRACT FROM AUTHOR]

3D printing involves the development of inks that exhibit the requisite properties for both printing and the intended application. In bioprinting, these inks are often hydrogels with controlled rheological properties that can be stabilized after deposition. Here, an alternate approach is developed where the ink is composed exclusively of jammed microgels, which are designed to incorporate a range of properties through microgel design (e.g., composition, size) and through the mixing of microgels. The jammed microgel inks are shear‐thinning to permit flow and rapidly recover upon deposition, including on surfaces or when deposited in 3D within hydrogel supports, and can be further stabilized with secondary cross‐linking. This platform allows the use of microgels engineered from various materials (e.g., thiol‐ene cross‐linked hyaluronic acid (HA), photo‐cross‐linked poly(ethylene glycol), thermo‐sensitive agarose) and that incorporate cells, where the jamming process and printing do not decrease cell viability. The versatility of this particle‐based approach opens up numerous potential biomedical applications through the printing of a more diverse set of inks. Microgels are jammed to formulate inks useful for 3D printing. Microgels are fabricated on microfluidic devices and jammed to form shear‐thinning solids where individual microgels can be designed with various chemical compositions or to contain cells. The microgel inks can be printed onto surfaces or into 3D hydrogels to produce diverse structures. [ABSTRACT FROM AUTHOR]

We assessed the associations between the APOA5¿¿-1131T>C polymorphism and lipid parameters and other risk factors of the metabolic syndrome in Korean subjects. A total of 2,901 participants from 20 oriental medical hospitals in Korea were enrolled between 2006 and 2011. According to the modified National Cholesterol Education Program Adult Treatment Panel III definitions, subjects were classified into the metabolic syndrome group and control group. The APOA5¿¿-1131T>C genotype was significantly associated with serum high-density lipoprotein cholesterol levels (effect = -¿1.700¿mg/dL, P=6.550-E07) in the total study population after adjustment for differences in age and gender. The association of the APOA5¿¿-1131T>C genotype with serum log-transformed triglyceride was also significant in an additive genetic model (effect = 0.056¿mg/dL, P=2.286E-19). After adjustment for age and gender, we determined that the odds ratio for the occurrence of the metabolic syndrome was 1.322 for C-allele carriers in the additive model (95% CI = [1.165 - 1.501], P=1.48E-05). In the current study, we demonstrated that the APOA5¿¿-1131T>C polymorphism is associated with the metabolic syndrome because of its remarkable effect on serum triglyceride levels in Korean subjects. [ABSTRACT FROM AUTHOR]