There are limited proven therapeutic options for the prevention and treatment of COVID-19. The role of vitamin and mineral supplementation or “immunonutrition” has previously been explored in a number of clinical trials in intensive care settings, and there are several hypotheses to support their routine use. The aim of this narrative review was to investigate whether vitamin supplementation is beneficial in COVID-19. A systematic search strategy with a narrative literature summary was designed, using the Medline, EMBASE, Cochrane Trials Register, WHO International Clinical Trial Registry, and Nexis media databases. The immune-mediating, antioxidant and antimicrobial roles of vitamins A to E were explored and their potential role in the fight against COVID-19 was evaluated. The major topics extracted for narrative synthesis were physiological and immunological roles of each vitamin, their role in respiratory infections, acute respiratory distress syndrome (ARDS), and COVID-19. Vitamins A to E highlighted potentially beneficial roles in the fight against COVID-19 via antioxidant effects, immunomodulation, enhancing natural barriers, and local paracrine signaling. Level 1 and 2 evidence supports the use of thiamine, vitamin C, and vitamin D in COVID-like respiratory diseases, ARDS, and sepsis. Although there are currently no published clinical trials due to the novelty of SARS-CoV-2 infection, there is pathophysiologic rationale for exploring the use of vitamins in this global pandemic, supported by early anecdotal reports from international groups. The final outcomes of ongoing trials of vitamin supplementation are awaited with interest.

BackgroundSurgeons need guidance regarding appropriate personal protective equipment (PPE) during the COVID-19 pandemic based on scientific evidence rather than availability. The aim of this paper is to inform surgeons of appropriate PPE requirements, and to discuss usage, availability, rationing and future solutions.

There are limited proven therapies for COVID-19. Vitamin C’s antioxidant, anti-inflammatory and immunomodulating effects make it a potential therapeutic candidate, both for the prevention and amelioration of COVID-19 infection, and as an adjunctive therapy in the critical care of COVID-19. This literature review focuses on vitamin C deficiency in respiratory infections, including COVID-19, and the mechanisms of action in infectious disease, including support of the stress response, its role in preventing and treating colds and pneumonia, and its role in treating sepsis and COVID-19. The evidence to date indicates that oral vitamin C (2–8 g/day) may reduce the incidence and duration of respiratory infections and intravenous vitamin C (6–24 g/day) has been shown to reduce mortality, intensive care unit (ICU) and hospital stays, and time on mechanical ventilation for severe respiratory infections. Further trials are urgently warranted. Given the favourable safety profile and low cost of vitamin C, and the frequency of vitamin C deficiency in respiratory infections, it may be worthwhile testing patients’ vitamin C status and treating them accordingly with intravenous administration within ICUs and oral administration in hospitalised persons with COVID-19.

The pursuit of appropriate, biocompatible materials is one of the primary challenges in translational bioprinting. The requirement to refine a biomaterial into a bioink places additional demands on the criteria for candidate biomaterials. The material must enable extrusion as a liquid bioink and yet be capable of maintaining its shape in the post-printing phase to yield viable tissues, organs and biological materials. Plant-derived biomaterials show great promise in harnessing both the natural strength of plant microarchitecture combined with their natural biological roles as supporters of cell growth. The aim of this review article is to outline the most widely used biomaterials derived from land plants and marine algae: nanocellulose, pectin, starch, alginate, agarose, fucoidan, and carrageenan, with an in-depth focus on nanocellulose and alginate. The properties that render these materials as promising bioinks for three dimensional bioprinting is herein discussed alongside their potential in 3D bioprinting for tissue engineering, drug delivery, wound healing, and implantable medical devices.

Introduction: The disciplines of 3D bioprinting and surgery have witnessed incremental transformations over the last century. 3D bioprinting is a convergence of biology and engineering technologies, mirroring the clinical need to produce viable biological tissue through advancements in printing, regenerative medicine and materials science. To outline the current and future challenges of 3D bioprinting technology in surgery.Methods: A comprehensive literature search was undertaken using the MEDLINE, EMBASE and Google Scholar databases between 2000 and 2019. A narrative synthesis of the resulting literature was produced to discuss 3D bioprinting, current and future challenges, the role in personalized medicine and transplantation surgery and the global 3D bioprinting market.Results: The next 20 years will see the advent of bioprinted implants for surgical use, however the path to clinical incorporation will be fraught with an array of ethical, regulatory and technical challenges of which each must be surmounted. Previous clinical cases where regulatory processes have been bypassed have led to poor outcomes and controversy. Speculated roles of 3D bioprinting in surgery include the production of de novo organs for transplantation and use of autologous cellular material for personalized medicine. The promise of these technologies has sparked an industrial revolution, leading to an exponential growth of the 3D bioprinting market worth billions of dollars.Conclusion: Effective translation requires the input of scientists, engineers, clinicians, and regulatory bodies: there is a need for a collaborative effort to translate this impactful technology into a real-world healthcare setting and potentially transform the future of surgery.

There are limited proven therapies for the treatment of COVID-19. Vitamin C’s antioxidant, anti-inflammatory and immunomodulating effects, make it a potential therapeutic candidate, both for the prevention and amelioration of COVID-19 infection, and as an adjunctive therapy in the critical care of COVID-19, supporting anti-inflammatory treatment. This literature review focuses on vitamin C deficiency in respiratory infections including COVID-19; the mechanism of action in infectious disease and adrenal function supporting the anti-inflammatory actions of glucocorticosteroids: its role in preventing and treating colds and pneumonia and its role in treating sepsis and COVID-19. The evidence to date indicates that oral vitamin C (2-8g/d) may reduce incidence and duration of respiratory infections and intravenous vitamin C (2-24g/d) has been shown to reduce mortality, Intensive Care Unit and hospital stays, time on mechanical ventilation in severe respiratory infections. Further trials are urgently warranted. Given the favourable safety profile and low cost of vitamin C, and frequency of vitamin C deficiency in respiratory infections it may be worthwhile testing patients’ vitamin C status and treating accordingly with intravenous use within ICUs and orally with doses between 2 and 8g/day in hospitalised and infected persons.

Purpose: Bioprinting is becoming an increasingly popular platform technology for engineering a variety of tissue types. Our aim was to identify biomaterials that have been found to be suitable for extrusion 3D bioprinting, outline their biomechanical properties and biocompatibility towards their application for bioprinting specific tissue types. This systematic review provides an in-depth overview of current biomaterials suitable for extrusion to aid bioink selection for specific research purposes and facilitate design of novel tailored bioinks.Methods: A systematic search was performed on EMBASE, PubMed, Scopus and Web of Science databases according to the PRISMA guidelines. References of relevant articles, between December 2006 to January 2018, on candidate bioinks used in extrusion 3D bioprinting were reviewed by two independent investigators against standardised inclusion and exclusion criteria. Data was extracted on bioprinter brand and model, printing technique and specifications (speed and resolution), bioink material and class of mechanical assessment, cell type, viability, and target tissue. Also noted were authors, study design (in vitro/in vivo), study duration and year of publication.Results: A total of 9,720 studies were identified, 123 of which met inclusion criteria, consisting of a total of 58 reports using natural biomaterials, 26 using synthetic biomaterials and 39 using a combination of biomaterials as bioinks. Alginate (n = 50) and PCL (n = 33) were the most commonly used bioinks, followed by gelatin (n = 18) and methacrylated gelatin (GelMA) (n = 16). Pneumatic extrusion bioprinting techniques were the most common (n = 78), followed by piston (n = 28). The majority of studies focus on the target tissue, most commonly bone and cartilage, and investigate only one bioink rather than assessing a range to identify those with the most promising printability and biocompatibility characteristics. The Bioscaffolder (GeSiM, Germany), 3D Discovery (regenHU, Switzerland), and Bioplotter (EnvisionTEC, Germany) were the most commonly used commercial bioprinters (n = 35 in total), but groups most often opted to create their own in-house devices (n = 20). Many studies also failed to specify whether the mechanical data reflected pre-, during or post-printing, pre- or post-crosslinking and with or without cells.Conclusions: Despite the continued increase in the variety of biocompatible synthetic materials available, there has been a shift change towards using natural rather than synthetic bioinks for extrusion bioprinting, dominated by alginate either alone or in combination with other biomaterials. On qualitative analysis, no link was demonstrated between the type of bioink or extrusion technique and the target tissue, indicating that bioprinting research is in its infancy with no established tissue specific bioinks or bioprinting techniques. Further research is needed on side-by-side characterisation of bioinks with standardisation of the type and timing of biomechanical assessment.

There are limited proven therapies for the treatment of COVID-19. Vitamin C’s antioxidant, anti-inflammatory and immunomodulating effects, make it a potential therapeutic candidate, both for the prevention and amelioration of COVID-19 infection, and as an adjunctive therapy in the critical care of COVID-19, supporting anti-inflammatory treatment. This literature review focuses on vitamin C deficiency in respiratory infections including COVID-19; the mechanism of action in infectious disease and adrenal function supporting the anti-inflammatory actions of glucocorticosteroids: its role in preventing and treating colds and pneumonia and its role in treating sepsis and COVID-19. The evidence to date indicates that oral vitamin C (2-8g/d) may reduce incidence and duration of respiratory infections and intravenous vitamin C (2-24g/d) has been shown to reduce mortality, Intensive Care Unit and hospital stays, time on mechanical ventilation in severe respiratory infections. Further trials are urgently warranted. Given the favourable safety profile and low cost of vitamin C, and frequency of vitamin C deficiency in respiratory infections it may be worthwhile testing patients’ vitamin C status and treating accordingly with intravenous use within ICUs and orally with doses between 2 and 8g/day in hospitalised and infected persons.