Mechanobiologic signals regulate cellular responses under physiologic and pathologic conditions. Using synthetic biology and tissue engineering, we developed a mechanically responsive bioartificial tissue that responds to mechanical loading to produce a preprogrammed therapeutic biologic drug. By deconstructing the signaling networks induced by activation of the mechanically sensitive ion channel transient receptor potential vanilloid 4 (TRPV4), we created synthetic TRPV4-responsive genetic circuits in chondrocytes. We engineered these cells into living tissues that respond to mechanical loading by producing the anti-inflammatory biologic drug interleukin-1 receptor antagonist. Chondrocyte TRPV4 is activated by osmotic loading and not by direct cellular deformation, suggesting that tissue loading is transduced into an osmotic signal that activates TRPV4. Either osmotic or mechanical loading of tissues transduced with TRPV4-responsive circuits protected constructs from inflammatory degradation by interleukin-1α. This synthetic mechanobiology approach was used to develop a mechanogenetic system to enable long-term, autonomously regulated drug delivery driven by physiologically relevant loading.

Mechanobiologic signals play critical roles in regulating cellular responses under both physiologic and pathologic conditions. Using a combination of synthetic biology and tissue engineering, we developed a mechanically-responsive bioartificial tissue that responds to mechanical loading to produce a pre-programmed therapeutic biologic drug. By deconstructing the signaling networks induced by activation of the mechanically-sensitive ion channel transient receptor potential vanilloid 4 (TRPV4), we created synthetic TRPV4-responsive genetic circuits in chondrocytes. These cells were then engineered into living tissues constructs that respond to mechanical compression to drive the production of the antiinflammatory biologic interleukin-1 receptor antagonist. Mechanical loading of these tissues constructs in the presence of the cytokine interleukin-1a protected constructs from inflammatory degradation. This "mechanogenetic" approach enables long-term autonomous delivery of therapeutic compounds that are driven by physiologically-relevant mechanical loading with cell-scale mechanical force resolution. The development of synthetic mechanogenetic gene circuits provides a novel approach for the autonomous regulation of cell-based drug delivery systems.

patients were counselled regarding the impact of TT on spermatogenesis and encouraged to discontinue TT if possible. During VR, vasal and epididymal fluid (as indicated) was sampled and each aspirate underwent microscopic evaluation for sperm presence and quality and was categorized as: motile sperm/intact-non-motile sperm/sperm parts/ no sperm. Rates of sperm presence/absence in the vasal/epididymal fluid, frequency of VV/VE, post-operative patency (presence of motile sperm) and semen parameters were compared among patients on TT vs. clinically-matched patients not using TT at the time of VR.RESULTS: Among the 2622 VRs reviewed, 54 men (2%) reported using TT at the time of their VR. Despite its impact on spermatogenesis, intra-operative microscopic analysis of the reproductive fluid (vasal or epididymal) identified the presence of sperm in 95% (51/54) of patients. Testis biopsy confirmed sperm production among 3 patients with absence of sperm within the vasal or epididymal fluid. Rates of VV or VE, did not significantly differ among men using TT at the time of VR compared to nonusers. Post-operative patency rates (TT:78 % vs. No TT:94%) and mean total motile sperm counts (TMC) were lower among patients using TT at the time of VR (7.9 vs. 28.3, p[0.02).CONCLUSIONS: Use of TT at the time of VR does not appear to impact rates of intra-operative microscopic identification of sperm within the reproductive fluid or the indication for VV/VE. Postoperative patency rates and total motile sperm counts may be lowered by use of TT. Moreover, the determination to the etiology azoospermia post-operatively (production vs. obstruction) may be clouded by the use of TT during VR.

level changes in BCG induction rates before and during the shortage period.RESULTS: 7971 patients were included in our study. The proportion of eligible patients receiving BCG induction therapy decreased 5.9%, from 38.9% (1030 of 2648 patients) in the pre-shortage period, to 33.0% (1756 of 5323 patients) in the shortage period (p<0.001). Mitomycin C use increased from 24.6% in 2010 to a peak in 30.9% in 2014 and 2015 (p[0.001). The use of gemcitabine remained stable (p[0.55). Among 19 states reporting data on !50 patients, 16 (84%) had a decrease in BCG initiation rate during the shortage period, ranging from 5.1% (New Jersey) to 35.5% (Washington).CONCLUSIONS: During the BCG drug shortage, BCG use for non-muscle invasive bladder cancer decreased with a compensatory rise in mitomycin C. A large variation in state-level BCG utilization may reflect differences in regional practice patterns or BCG availability.

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