We present a microfabricated hybrid biopolymer microcantilever, in which the contractile force of self-organized cardiomyocytes can be measured and studied, as a prototype for the development of cell-driven actuators. The microcantilever is made of a flexible, transparent, biocompatible poly(dimethylsiloxane) substrate, using a simple microfabrication technique. Seeding and culturing cardiomyocytes on the specific cantilever allows us to perform highly sensitive, quantitative, and noninvasive measurement of the contractile force of the self-organized cells in real time. The motions of the microcantilever showed good agreement with an analytical solution based on Stoney's equation and finite element modeling (FEM) of the hybrid system. Immunostaining of the cells on the hybrid system showed continuous high-order coalignment of actin filaments and parallel sarcomeric organization in the direction of the longitudinal axis of the microcantilever without structural constraints, such as microgrooves or lines, and proved our FEM and the synchronous contraction of cardiomyocytes. The presented device should facilitate measurement of the contractile force of self-organized cardiomyocytes on a specific area, which may help the understanding of heart failure and the design of optimal hybrid biopolymer actuators, as well as assist development of a microscale cell-driven motor system.

A two-photon excitable molecular probe for fluoride, developed based on a fluoride-specific desilylation reaction, is demonstrated to be useful for fluorescent imaging of fluoride ions in live zebrafish by one-photon as well as two-photon microscopy for the first time.

The authors investigated the clinical value of intraoperative periarticular multimodal drug injections (PMDI) in patients on continuous epidural analgesia after simultaneous bilateral TKAs. In 55 patients scheduled to undergo simultaneous bilateral TKAs, one knee was randomly assigned to the PMDI group for which intraoperative periarticular injections were administered and the other knee was assigned to the No-PMDI group for which the injections were not done. These two groups were compared for pain level (during the operation night and on postoperative days (POD) 1, 4, and 7), functional recovery (ability to perform straight leg raising on POD 1 and maximum flexion on POD 7), patient satisfaction (POD 7), and the incidence of wound complications. The PMDI group showed a lower pain level during the operation night and on POD 1 than the No-PMDI group, but no differences in pain levels were observed between the groups on POD 4 or 7. Furthermore, no significant group differences were found in terms of functional recovery, patient satisfaction. No wound complication has been occurred in the PMDI group. This study demonstrates that PMDI provides additional pain relief limited to the immediate postoperative period but does not improve pain relief after POD 1, patient satisfaction and functional recovery.

This work provides insight into a novel strategy of enhancing the durability of a lubricant-infused surface for sustainable drag reduction.