Fabrication and In Vitro Characterization of a Tissue Engineered PCL-PLLA Heart Valve.

Heart valve diseases are among the leading causes of cardiac failure around the globe. Nearly 90,000 heart valve replacements occur in the USA annually. Currently, available options for heart valve replacement include bioprosthetic and mechanical valves, both of which have severe limitations. Bioprosthetic valves can last for only 10-20 years while patients with mechanical valves always require blood-thinning medications throughout the remainder of the patient's life. Tissue engineering has emerged as a promising solution for the development of a viable, biocompatible and durable heart valve; however, a human implantable tissue engineered heart valve is yet to be achieved. In this study, a tri-leaflet heart valve structure is developed using electrospun polycaprolactone (PCL) and poly L-lactic acid (PLLA) scaffolds, and a set of in vitro testing protocol has been developed for routine manufacturing of tissue engineered heart valves. Stress-strain curves were obtained for mechanical characterization of different valves. The performances of the developed valves were hemodynamically tested using a pulse duplicator, and an echocardiography machine. Results confirmed the superiority of the PCL-PLLA heart valve compared to pure PCL or pure PLLA. The developed in vitro test protocol involving pulse duplicator and echocardiography tests have enormous potential for routine application in tissue engineering of heart valves

Mesenchymal Stem Cells in the Treatment of Traumatic Brain Injury.

Traumatic brain injury (TBI) is characterized by a disruption in the normal function of the brain due to an injury following a trauma, which can potentially cause severe physical, cognitive, and emotional impairment. The primary insult to the brain initiates secondary injury cascades consisting of multiple complex biochemical responses of the brain that significantly influence the overall severity of the brain damage and clinical sequelae. The use of mesenchymal stem cells (MSCs) offers huge potential for application in the treatment of TBI. MSCs have immunosuppressive properties that reduce inflammation in injured tissue. As such, they could be used to modulate the secondary mechanisms of injury and halt the progression of the secondary insult in the brain after injury. Particularly, MSCs are capable of secreting growth factors that facilitate the regrowth of neurons in the brain. The relative abundance of harvest sources of MSCs also makes them particularly appealing. Recently, numerous studies have investigated the effects of infusion of MSCs into animal models of TBI. The results have shown significant improvement in the motor function of the damaged brain tissues. In this review, we summarize the recent advances in the application of MSCs in the treatment of TBI. The review starts with a brief introduction of the pathophysiology of TBI, followed by the biology of MSCs, and the application of MSCs in TBI treatment. The challenges associated with the application of MSCs in the treatment of TBI and strategies to address those challenges in the future have also been discussed

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Medium term results of total knee arthroplasty as a primary treatment for knee fractures

Introduction: Successful treatment of knee comminuted periarticular fractures associated with osteoporosis and pre-existing arthritis is a challenging task. Methods: This is a prospective study on 27 patients who had comminuted intra and periarticular knee fractures and pre-existing arthritis. Fractures were classified according to Muller's AO classification. Primary knee arthroplasty was performed ± internal fixation following 4 weeks of splinting. A stem was added to the tibial tray and Legacy Constrained Condylar Knee (LCCK) or Rotating Hinge (RH) prosthesis were used depending on the level of ligament damage and bone defects. The Knee Society Score (KSS) and radiological evaluation were performed at 3, 6 and 12 months then annually thereafter. Results: The average age of this group of patients was 63 years (range 59–74). Sixteen knees received primary femoral component and Posterior Stabilized insert, while 8 had LCCK. RH implants were chosen in 2 and distal femoral replacement was necessary in one knee. Twenty five patients were available for the final review at an average 6 years in whom the KSS was 80 (range 75–89) points. All patients achieved full knee extension and average knee flexion of 110° (range 90–135°). One knee needed re-admission for early Debridement Antibiotic Irrigation and Retention (DAIR) but none of the knees was revised or awaiting revision. Conclusion: Knee arthroplasty achieves highly successful outcome when performed as a primary treatment for comminuted intra and periarticular knee fractures in elderly patients. Survival of implants and functional range of movement at midterm are excellent