Biomechanical Aspects in Bone Tumor Engineering

In the past decades, anticancer drug development brought the field of tumor engineering to a new level by the need of robust test systems. Simulating tumor microenvironment in vitro remains a challenge, and osteosarcoma-the most common primary bone cancer-is no exception. The growing evidence points to the inevitable connection between biomechanical stimuli and tumor chemosensitivity and aggressiveness, thus making this component of the microenvironment a mandatory requirement to the developed models. In this review, we addressed the question: is the "in vivo - in vitro" gap in osteosarcoma engineering bridged from the perspective of biomechanical stimuli? The most notable biomechanical cues in the tumor cell microenvironment are observed and compared in the contexts of in vivo conditions and engineered three-dimensional in vitro models. Impact statement The importance of biomechanical stimuli in three-dimensional in vitro models for drug testing is becoming more pronounced nowadays. This review might assist in understanding the key players of the biophysical environment of primary bone cancer and the current state of bone tumor engineering from this perspective.

Portable, low-cost, Raspberry Pi-based optical sensor (PiSENS): continuous monitoring of atmospheric nitrogen dioxide

We have developed a sensing system that utilizes a low-cost computer (Raspberry Pi) and its imaging camera as an optical sensing core for the continuous detection of NO₂ in the air (PiSENS-A). The sensor is based on colour development as a consequence of the interaction of the gas with an absorbing solution. The PiSENS-A is thoroughly calibrated over the hourly mean which is used as one of the key metrics in evaluating air quality. The calibration was performed in the range of 0 < [NO₂] < 476 μg m^-3 chosen to contain the threshold used to determine compliance to the UK's Air Quality Standard Regulations (2010) expressed as a maximum of 18 permitted exceedances of [NO₂]_{hourly mean} = 200 μg per m³ per year. Lab-based measurements were evaluated against UV-vis. The average precision expressed as a relative standard deviation was: RSD% = 2.8%, while the correlation of mock samples was excellent (Pearson's r = 1.000). Field-based measurements were evaluated against chemiluminescence-based instrument exhibiting a correlation coefficient of R² = 0.993. The PiSENS-A was also deployed as an independent air quality analyser at the Keele University campus.