Shear-Induced Encapsulation into Red Blood Cells: A New Microfluidic Approach to Drug Delivery

Encapsulating molecules into red blood cells (RBCs) is a challenging topic for drug delivery in clinical practice, allowing to prolong the residence time in the body and to avoid toxic residuals. Fluidic shear stress is able to temporary open the membrane pores of RBCs, thus allowing for the diffusion of a drug in solution with the cells. In this paper, both a computational and an experimental approach were used to investigate the mechanism of shear-induced encapsulation in a microchannel. By means of a computational fluid dynamic model of a cell suspension, it was possible to calculate an encapsulation index that accounts for the effective shear acting on the cells, their distribution in the cross section of the microchannel and their velocity. The computational model was then validated with micro-PIV measurements on a RBCs suspension. Finally, experimental tests with a microfluidic channel showed that, by choosing the proper concentration and fluid flow rate, it is possible to successfully encapsulate a test molecule (FITC-Dextran, 40 kDa) into human RBCs. Cytofluorimetric analysis and confocal microscopy were used to assess the RBCs physiological shape preservation and confirm the presence of fluorescent molecules inside the cells

Weak biophoton emission after laser surgery application in soft tissues: Analysis of the optical features

Nowadays, laser scalpels are commonly used in surgery, replacing the traditional surgical scalpels for several applications involving cutting or ablating living biological tissue. Laser scalpels are generally used to concentrate light energy in a very small-sized area; light energy is then converted in heat by the tissues. In other cases, the fiber glass tip of the laser scalpel is heated to high temperature and used to cut the tissues. Depending on the temperature reached in the irradiated area, different effects are visible in the tissues. In this study, we report the discovery and characterization of the light emitted by soft mammalian biological tissues from seconds to hours after laser surgery application. A laser diode (with hot fiber glass tip) working at 808 nm and commercially available for medical and dentistry applications was used. The irradiated tissues (red meat, chicken breast and fat) showed light emission in the visible range, well detectable with a commercial charge coupled device (CCD) camera. The time decay of the light emission, the laser power effects and the spectral features in the range 500 to 840 nm in the different tissues are here reported

Problematic social media use: Associations with health complaints among adolescents

Objective. Problematic Social Media Use (PSMU) has an addictive potential for young users. The aim of this study was to show the prevalence of PSMU across Italian regions and its association with health complaints. Materials and methods. Data are gathered from the Italian 2018 Health Behaviour in School-aged Children survey using a representative sample of Italian adolescents aged 11, 13 and 15 years (50.6% males). Participants completed self-administered questionnaires assessing PSMU and health complaints. Results. PSMU affects 8.9% adolescents in Italy and the prevalence is quite consistent across regions. 13-year-olds girls showed the highest percentage of PSMU (13%). Problematic users of social media are more likely to report multiple somatic (OR = 1.84 [95% CI 1.82-1.85]) and psychological (OR = 2.60 [95% CI 2.58-2.63]) symptoms. Conclusions. PSMU represents a widespread problem in Italy. National prevention interventions are needed in order to promote a positive use of social media