Global prevalence of suicide in cancer patients: a systematic review and meta-analysis

Aim: Given that patients with cancer may commit suicide due to physical and mental problems, the present study objectives were to identify particular risk factors of different subgroup of patients including type of cancer, gender, age, type and time of suicide, and geographical region to facilitate early care and psychosocial support. Methods: A comprehensive review of databases including Embase, Scopus, PubMed, and Web of Science was conducted for original articles published in English from January 2000 to March 2022. It is based on the PRISMA checklist. Results: After reviewing 69 articles selected from 15 countries, the total prevalence rate of suicide among 34,157,856 patients with cancer was estimated 67,169, at 0.013 (95% CI, 0.008–0.021). The highest suicide prevalence was related to gastrointestinal cancer, estimated at 0.204 (95% CI, 0.161–0.255). A gender-based meta-analysis showed that the prevalence of suicide/suicidal ideation was higher among men, estimated at 0.013 (95% CI, 0.008–0.023) compared with women, at 0.006 (95% CI, 0.002–0.017). Conclusion: Based on study results, suicide-prevention strategies should be aimed at patients younger than 40 years of age to effectively resolve their mental health disorders and promote their self-efficacy in successful management of the disease

In vitro evaluation of carbon-nanotube-reinforced bioprintable vascular conduits

Vascularization of thick engineered tissue and organ constructs like the heart, liver, pancreas or kidney remains a major challenge in tissue engineering. Vascularization is needed to supply oxygen and nutrients and remove waste in living tissues and organs through a network that should possess high perfusion ability and significant mechanical strength and elasticity. In this thesis, we introduce a fabrication process to print vascular conduits directly, where conduits were reinforced with carbon nanotubes (CNTs) to enhance their mechanical properties and bioprintability. The generation of vascular conduit with a natural polymer hydrogel such as alginate needs to have improved mechanical properties in order to biomimic the natural vascular system. Carbon nanotube (CNT) is one of the best candidates for this goal because it is known as the strongest material and possesses a simple structure. In this thesis, multi-wall carbon nanotube (MWCNT) is dispersed homogenously in the hydrogel and fabricated through an extrusion-based system.In vitro evaluation of printed conduits encapsulated in human coronary artery smooth muscle cells was performed to characterize the effects of CNT reinforcement on the mechanical, perfusion and biological performance of the conduits. Perfusion and permeability, cell viability, extracellular matrix formation and tissue histology were assessed and discussed, and it was concluded that CNT-reinforced vascular conduits provided a foundation for mechanically appealing constructs where CNTs could be replaced with natural protein nanofibers for further integration of these conduits in large-scale tissue fabrication. It was concluded that MWCNT has a significant effect on mechanical properties, vascular conduit swelling ratio and biological characterization in short-term and long-term cellular viability