Challenges in organ transplantation

The impact of heart valve and partial heart transplant models on the development of banking methods for tissues and organs: A concise review

Cryopreserved human heart valves fill a crucial role in the treatment for congenital cardiac anomalies, since the use of alternative mechanical and xenogeneic tissue valves have historically been limited in babies. Heart valve models have been used since 1998 to better understand the impact of cryopreservation variables on the heart valve tissue components with the ultimate goals of improving cryopreserved tissue outcomes and potentially extrapolating results with tissues to organs. Cryopreservation traditionally relies on conventional freezing, employing cryoprotective agents, and slow cooling to sub-zero centigrade temperatures; but it is plagued by the formation of ice crystals and cell damage upon thawing. Researchers have identified ice-free vitrification procedures and developed a new rapid warming method termed nanowarming. Nanowarming is an emerging method that utilizes targeted application of energy at the nanoscale level to rapidly rewarm vitrified tissues, such as heart valves, uniformly for transplantation. Vitrification and nanowarming methods hold great promise for surgery, enabling the storage and transplantation of tissues for various applications, including tissue repair and replacement. These innovations have the potential to revolutionize complex tissue and organ transplantation, including partial heart transplantation. Banking these grafts addresses organ scarcity by extending preservation duration while preserving biological activity with maintenance of structural fidelity. While ice-free vitrification and nanowarming show remarkable potential, they are still in early development. Further interdisciplinary research must be dedicated to exploring the remaining challenges that include scalability, optimizing cryoprotectant solutions, and ensuring long-term viability upon rewarming in vitro and in vivo.

Asian Pacific Association for the Study of the Liver clinical practice guidelines on liver transplantation

Liver transplantation is a highly complex and challenging field of clinical practice. Although it was originally developed in western countries, it has been further advanced in Asian countries through the use of living donor liver transplantation. This method of transplantation is the only available option in many countries in the Asia-Pacific region due to the lack of deceased organ donation. As a result of this clinical situation, there is a growing need for guidelines that are specific to the Asia-Pacific region. These guidelines provide comprehensive recommendations for evidence-based management throughout the entire process of liver transplantation, covering both deceased and living donor liver transplantation. In addition, the development of these guidelines has been a collaborative effort between medical professionals from various countries in the region. This has allowed for the inclusion of diverse perspectives and experiences, leading to a more comprehensive and effective set of guidelines.

An Overview on the Big Players in Bone Tissue Engineering: Biomaterials, Scaffolds and Cells

Presently, millions worldwide suffer from degenerative and inflammatory bone and joint issues, comprising roughly half of chronic ailments in those over 50, leading to prolonged discomfort and physical limitations. These conditions become more prevalent with age and lifestyle factors, escalating due to the growing elderly populace. Addressing these challenges often entails surgical interventions utilizing implants or bone grafts, though these treatments may entail complications such as pain and tissue death at donor sites for grafts, along with immune rejection. To surmount these challenges, tissue engineering has emerged as a promising avenue for bone injury repair and reconstruction. It involves the use of different biomaterials and the development of three-dimensional porous matrices and scaffolds, alongside osteoprogenitor cells and growth factors to stimulate natural tissue regeneration. This review compiles methodologies that can be used to develop biomaterials that are important in bone tissue replacement and regeneration. Biomaterials for orthopedic implants, several scaffold types and production methods, as well as techniques to assess biomaterials' suitability for human use-both in laboratory settings and within living organisms-are discussed. Even though researchers have had some success, there is still room for improvements in their processing techniques, especially the ones that make scaffolds mechanically stronger without weakening their biological characteristics. Bone tissue engineering is therefore a promising area due to the rise in bone-related injuries.

Three dimensional (bio)printing of blood vessels: from vascularized tissues to functional arteries

Tissue engineering has emerged as a strategy for producing functional tissues and organs to treat diseases and injuries. Many chronic conditions directly or indirectly affect normal blood vessel functioning, necessary for material exchange and transport through the body and within tissue-engineered constructs. The interest in vascular tissue engineering is due to two reasons: (1) functional grafts can be used to replace diseased blood vessels, and (2) engineering effective vasculature within other engineered tissues enables connection with the host's circulatory system, supporting their survival. Among various practices, (bio)printing has emerged as a powerful tool to engineer biomimetic constructs. This has been made possible with precise control of cell deposition and matrix environment along with the advancements in biomaterials. (Bio)printing has been used for both engineering stand-alone vascular grafts as well as vasculature within engineered tissues for regenerative applications. In this review article, we discuss various conditions associated with blood vessels, the need for artificial blood vessels, the anatomy and physiology of different blood vessels, available 3D (bio)printing techniques to fabricate tissue-engineered vascular grafts and vasculature in scaffolds, and the comparison among the different techniques. We conclude our review with a brief discussion about future opportunities in the area of blood vessel tissue engineering.

Brain Death and Organ Transplantation in Nepal: Navigating Cultural, Legal, and Ethical Landscapes

Organ transplantation after brain death is challenging in Nepal due to cultural beliefs, legal frameworks, and ethical considerations. The Human Body Organ Transplantation (Regulation and Prohibition) Act (HBOTA) has not met with substantial success after its amendment. This review critically appraises the current state of brain death and organ transplantation in Nepal. It explores challenges, evaluates progress, and provides recommendations. Literature review of databases was conducted to find articles on brain death, organ donation, and transplantation in Nepal. Analysis of cultural, legal, ethical, and practical factors influencing implementation. Key challenges include limited awareness, religious beliefs, infrastructure gaps, and family consent barriers. HBOTA amendments in 2016 enabled brain death donations, however, donation rates remain low. Strategies are needed to improve public education, resources, personnel training, and collaboration. Cultural sensitivity and stakeholder engagement are crucial. A multifaceted approach addressing cultural, legal, ethical and practical dimensions is essential to improve organ donation rates in Nepal. Despite progress, substantial challenges persist requiring evidence-based strategies focused on awareness, capacity building, policy improvements, and culturally appropriate community engagement.

Organ Donation Awareness among Family Members of ICU Patients

Background and Objectives: With one of the lowest donation rates in the European Union, Romania faces challenges in organ donation from brain death donors, within an opt-in system. This study aims to measure the attitudes and knowledge of ICU patient's relatives toward organ donation. Materials and Methods: A descriptive cross-sectional study was conducted in the intensive care unit of the Emergency Clinical County Hospital of Oradea, Romania. A 24-item self-administered questionnaire (N = 251) was used to collect data on knowledge about organ and tissue donation and transplantation, as well as the willingness to donate. Results: A high degree of awareness and willingness for organ donation and transplantation was recorded. The main positive predictor of willingness to donate was the perception of helping others by donating their organs after brain death (β = 0.537, OR = 1.711, p < 0.05), and the main negative predictor was the idea that the whole body should be buried intact (β = -0.979, OR = 0.376, p < 0.01). Conclusions: A basic understanding of organ donation and transplantation and favorable attitudes toward organ donation were registered. Families' interviews for organ donation consent may be affected due to extreme emotional distress.

Pediatric Organ and Tissue Donation-A 10-Year Retrospective Study in Portugal

Organ and tissue donation can transform lives. One donor can ensure the survival of up to 8 people through their organs and improve the quality of life for dozens more through tissue donation. Portugal has an excellent transplantation rate, but deaths still occur while waiting for an organ. The study aimed to analyze pediatric organ and tissue donors nationally and evaluate brain deaths in a pediatric intensive care unit (PICU) over the past 10 years to identify any potential lost donors. We conducted a retrospective descriptive study of pediatric organ and tissue donors and diagnosed brain deaths from January 2011 to December 2021. Demographic and clinical data were analyzed, including those provided by the National Transplant Coordination. Over the past 10 years in Portugal, 121 pediatric donors (11.7 per million population) were collected, and 569 organs and tissues were collected. During the same period in the PICU, there were 125 deaths, including 20 brain deaths. Of this group, 4 were organ and tissue donors. In the non-donor group (n = 16), a potential lost donor case stands out. Pediatric specialists need to be more familiar with the donation process, which would enable the identification and optimization of all potential donors, thus minimizing the number of potentially lost organs.

Assessment of different manufacturing techniques for the production of bioartificial scaffolds as soft organ transplant substitutes

Introduction: The problem of organs' shortage for transplantation is widely known: different manufacturing techniques such as Solvent casting, Electrospinning and 3D Printing were considered to produce bioartificial scaffolds for tissue engineering purposes and possible transplantation substitutes. The advantages of manufacturing techniques' combination to develop hybrid scaffolds with increased performing properties was also evaluated. Methods: Scaffolds were produced using poly-L-lactide-co-caprolactone (PLA-PCL) copolymer and characterized for their morphological, biological, and mechanical features. Results: Hybrid scaffolds showed the best properties in terms of viability (>100%) and cell adhesion. Furthermore, their mechanical properties were found to be comparable with the reference values for soft tissues (range 1-10 MPa). Discussion: The created hybrid scaffolds pave the way for the future development of more complex systems capable of supporting, from a morphological, mechanical, and biological standpoint, the physiological needs of the tissues/organs to be transplanted.

Current state of clinical trials on xenograft

BACKGROUND

Xenotransplantation is a worth investing branch of science, since it aims to fulfil the demand on human cells, tissues and organs. Despite decades of consistent work in preclinical assessments, clinical trials on xenotransplantation are far from reaching the targeted goal. Our study aims to track the characteristics, assess the content and summarize the plan of each trial on skin, beta-island, bone marrow, aortic valve and kidney xenografts, leading to a clear sorting of efforts made in this field.

METHODS

In December 2022, we searched clinicaltrial.gov for interventional clinical trials related to xenograft of skin, pancreas, bone marrow, aortic valve and kidney. A total of 14 clinical trials are included in this study. Characteristics on each trial were gathered. Linked publications were searched using Medline/PubMed and Embase/Scopus. Content of trials was reviewed and summarized.

RESULTS

Only 14 clinical trials met our study's criteria. The majority were completed, and most of the trials' enrolment was between 11 and 50 participants. Nine trials used a xenograft of porcine origin. Six trials targeted skin xenotransplantation, four targeted β-cells, two targeted bone marrow and one trial targeted each of the kidney and aortic valve. The average length of trials was 3.38 years. Four trials were conducted in the United States and two trials in each of Brazil, Argentina and Sweden. Of all the included trials, none had any results provided and only three had published work. Phases I, III, and IV had only one trial each. A total of 501 participants were enrolled in these trials.

CONCLUSION

This study sheds the light on the current state of clinical trials on xenograft. Characteristically, trials on this field are of low number, low enrolment, short duration, few related publications and no published results. Porcine organs are the most used in these trials, and skin is the most studied organ. An extension of the literature is highly needed due to the variety of conflicts mentioned. Overall, this study sheds the light on the necessity of managing research efforts, leading to the initiation of more trials targeting the field of xenotransplantation.

Assessing the impact of COVID-19 on the performance of organ transplant services using data envelopment analysis

Organ transplant is one of the best options for many medical conditions, and in many cases, it may be the only treatment option. Recent evidence suggests, however, that the COVID-19 pandemic might have detrimentally affected the provision of this type of healthcare services. The main purpose of this article is to use Data Envelopment Analysis and the Malmquist Index to assess the impact that the pandemic caused by the novel coronavirus SARS-CoV-2 had on the provision of solid organ transplant services. To this purpose, we use three complementary models, each focusing on specific aspects of the organ donation and transplantation process, and data from Brazil, which has one of the most extensive public organ transplant programs in the world. Using data from 17 States plus the Federal District, the results of our analysis show a significant drop in the performance of the services in terms of the organ donation and transplantation process from 2018 to 2020, but the results also indicate that not all aspects of the process and States were equally affected. Furthermore, by using different models, this research also allows us to gain a more comprehensive and informative assessment of the performance of the States in delivering this type of service and identify opportunities for reciprocal learning, expanding our knowledge on this important issue and offering opportunities for further research.

The utility of machine learning for predicting donor discard in abdominal transplantation

BACKGROUND

Increasing access and better allocation of organs in the field of transplantation is a critical problem in clinical care. Limitations exist in accurately predicting allograft discard. Potential exists for machine learning to provide a balanced assessment of the potential for an organ to be used in a transplantation procedure.

METHODS

We accessed and utilized all available deceased donor United Network for Organ Sharing data from 1987 to 2020. With these data, we evaluated the performance of multiple machine learning methods for predicting organ use. The machine learning methods trialed included XGBoost, random forest, Naïve Bayes (NB), logistic regression, and fully connected feedforward neural network classifier methods. The top two methods, XGBoost and random forest, were fully developed using 10-fold cross-validation and Bayesian optimization of hyperparameters.

RESULTS

The top performing model at predicting liver organ use was an XGBoost model which achieved an AUC-ROC of .925, an AUC-PR of .868, and an F1 statistic of .756. The top performing model for predicting kidney organ use classification was an XGBoost model which achieved an AUC-ROC of .952, and AUC-PR of .883, and an F1 statistic of .786.

CONCLUSIONS

The XGBoost method demonstrated a significant improvement in predicting donor allograft discard for both kidney and livers in solid organ transplantation procedures. Machine learning methods are well suited to be incorporated into the clinical workflow; they can provide robust quantitative predictions and meaningful data insights for clinician consideration and transplantation decision-making.

Afucosylation of HLA-specific IgG1 as a potential predictor of antibody pathogenicity in kidney transplantation

Antibody-mediated rejection (AMR) is the leading cause of graft failure. While donor-specific antibodies (DSAs) are associated with a higher risk of AMR, not all patients with DSAs develop rejection, suggesting that the characteristics of alloantibodies determining their pathogenicity remain undefined. Using human leukocyte antigen (HLA)-A2-specific antibodies as a model, we apply systems serology tools to investigate qualitative features of immunoglobulin G (IgG) alloantibodies including Fc-glycosylation patterns and FcγR-binding properties. Levels of afucosylated anti-A2 antibodies are elevated in seropositive patients, especially those with AMR, suggesting potential cytotoxicity via FcγRIII-mediated mechanisms. Afucosylation of both glycoengineered monoclonal and naturally glycovariant polyclonal serum IgG specific to HLA-A2 drives potentiated binding to, slower dissociation from, and enhanced signaling through FcγRIII, a receptor widely expressed on innate effector cells, and greater cytotoxicity against HLA-A2+ cells mediated by natural killer (NK) cells. Collectively, these results suggest that afucosylated DSA may be a biomarker of AMR and contribute to pathogenesis.

Classic and Current Opinions in Human Organ and Tissue Transplantation

Graft tolerance is a pathophysiological condition heavily reliant on the dynamic interaction of the innate and adaptive immune systems. Genetic polymorphism determines immune responses to tissue/organ transplantation, and intricate humoral and cell-mediated mechanisms control these responses. In transplantation, the clinician's goal is to achieve a delicate equilibrium between the allogeneic immune response, undesired effects of the immunosuppressive drugs, and the existing morbidities that are potentially life-threatening. Transplant immunopathology involves sensitization, effector, and apoptosis phases which recruit and engages immunological cells like natural killer cells, lymphocytes, neutrophils, and monocytes. Similarly, these cells are involved in the transfer of normal or genetically engineered T cells. Advances in tissue transplantation would involve a profound knowledge of the molecular mechanisms that underpin the respective immunopathology involved and the design of precision medicines that are safe and effective.

Telemedicine in lung transplant to improve patient-centered care: A systematic review

OBJECTIVES

Long-term care combined with complex follow-up processes is among the essential needs of lung transplantation. Therefore, Telemedicine-based strategies can provide an effective approach for both patients and clinicians by applying remote patient monitoring. Hence, the main objective of this study was to investigate Telemedicine and telehealth usage in lung transplantation.

METHOD

A systematic review was conducted in four databases using keywords. Eligible studies were all English papers that developed Telemedicine-based programs to enhance patient care in lung organ transplantation. The interventions were analyzed analysis to determine the main descriptive areas. The quality of the included articles was evaluated using Mixed Methods Appraisal Tool (MMAT) tool by two authors.

RESULTS

Of the 261 retrieved articles, 27 met our inclusion criteria. Of these, 22 studies were devoted to the post-transplantation phase. All articles were published from 2002 to 2021 and the trend of publications has increased in recent years. Most of the studies were conducted in the United States and Canada. All eligible studies can be categorized into five types of Telemedicine interventions, 15 (55.56%) articles devoted to Telemonitoring, four (14.81%) for Teleconsultation, four (14.81%) articles for Telerehabilitation, three (11.11%) articles for Telespirometery, and one (3.70%) article were done regarding Tele-education.

CONCLUSION

This integrated review provides researchers with a new understanding of Telemedicine-based care solutions. Findings show that remote patient care in lung transplantation includes various aspects, especially self-care improvement.

Effect of Cell-Derived Matrices on Growth and Differentiation of Human Wharton's Jelly-Derived Mesenchymal Stem Cells

Cell-derived matrices (CDMs) are scaffolds constructed by decellularization of cellular matrices from different tissues and organs. Since CDMs mimic the extracellular matrices (ECMs) of native tissues, it plays an essential role in the preparation of bioscaffolds. CDM scaffolds from mesenchymal stem cells (MSCs) have been reported to support cell adhesion and proliferation of its own cells. Therefore, in this study we aimed to test if growth of human Wharton's jelly-derived MSCs may be enhanced when cultured on their own CDMs. To do this, MSCs were induced to generate ECM using ascorbic acid. Thus, obtained matrices were decellularized and characterized quantitatively for changes in their biochemical components (total protein, collagen, glycosaminoglycans) and qualitatively for fibronectin, laminin, and collagen (I & IV) by immunostaining. Our results show the retention of essential ECM components in the decellularized WJ-MSC-derived matrix (WJ-CDM). The influence of WJ-CDM on proliferation and differentiation of WJ-MSCs were evaluated by comparing their growth on collagen and fibronectin-only coated plates. A non-coated tissue culture polystyrene plate (TCPS) served as control. Our cell proliferation results show that no significant changes were observed in the proliferation of MSCs when cultured on WJ-CDM as compared to the bio-coated and non-coated cultures. However, gene expression analysis of the differentiation process showed that osteogenic and adipogenic differentiation potential of the WJ-MSCs was significantly increased upon culturing them on WJ-CDM. In conclusion, the present study reveals that the WJ-MSCs cultured on WJ-CDM may augment osteogenic and adipogenic differentiation.

Knowledge and Attitude Toward Organ Donation Among the Adult Population in Jazan, Saudi Arabia

Background

Organ transplantation is recognized as a life-saving procedure for patients with potentially terminal illnesses. However, the population's awareness of organ donation and related issues is variable throughout the world.

Objectives

The study purposes to evaluate the knowledge and attitude toward organ donation among the adult population in the Jazan region, Saudi Arabia.

Methods

We conducted a cross-sectional questionnaire-based study on the general population in Jazan using the convenient sampling method. The questionnaire was composed of 21 items distributed over demographic characteristics, knowledge, and attitude domains. The knowledge and attitude domain levels were categorized into low, moderate, and high based on the scoring of its items. The data had been analyzed using SPSS software version 23 (IBM Corp., Armonk, NY). Frequency and percentages were used to display categorical variables. Mean and standard deviation was used to present numerical variables. The independent t-test and analysis of variance (ANOVA) test were both used to test for factors associated with knowledge score and attitude score toward organ donation.

Results

A total of 1019 participants were included in the study. The majority were between the ages of 18 and 30 years and 3.4% of them were older than 50 years. Eighty percent of participants had a university level of education or higher and 48% were students. This survey showed that 493 (48.4%) had a moderate knowledge level of organ donation (total score between 50% and 75%) with younger age, being a student, and residence status associated with a higher level of knowledge while gender and the education levels were not. Five hundred one (49.2%) of the participants reported being in agreement with organ donation and 56 (5.5%) of them reported disagreement. Most of the participants exhibited a low positive attitude toward organ donation, with 592 (58.1%) of the participants (a total score less than 50%) (score of 4 and less). Young age and being a student were the factors associated with a positive attitude while gender, education levels, residence status, and monthly status were having no significant associations with the positive attitude toward organ donation.

Conclusion

This study concluded that study participants had a moderate level of knowledge and a low positive attitude toward organ donation. The advocacy in promoting organ donation should be increased through the use of appropriate mediums to change the attitudes and enhance the willingness of people.

Hydrogels for Tissue Engineering: Addressing Key Design Needs Toward Clinical Translation

Collapse

Single-Cellular Biological Effects of Cholesterol-Catabolic Bile Acid-Based Nano/Micro Capsules as Anti-Inflammatory Cell Protective Systems

Recent studies in our laboratories have shown promising effects of bile acids in ➀ drug encapsulation for oral targeted delivery (via capsule stabilization) particularly when encapsulated with Eudragit NM30D^® and ➁ viable-cell encapsulation and delivery (via supporting cell viability and biological activities, postencapsulation). Accordingly, this study aimed to investigate applications of bile acid-Eudragit NM30D^® capsules in viable-cell encapsulation ready for delivery. Mouse-cloned pancreatic β-cell line was cultured and cells encapsulated using bile acid-Eudragit NM30D^® capsules, and capsules' images, viability, inflammation, and bioenergetics of encapsulated cells assessed. The capsules' thermal and chemical stability assays were also assessed to ascertain an association between capsules' stability and cellular biological activities. Bile acid-Eudragit NM30D^® capsules showed improved cell viability (e.g., F1 < F2 & F8; p < 0.05), insulin, inflammatory profile, and bioenergetics as well as thermal and chemical stability, compared with control. These effects were formulation-dependent and suggest, overall, that changes in ratios of bile acids to Eudragit NM30D^® can change the microenvironment of the capsules and subsequent cellular biological activities.

MicroRNA Cues from Nature: A Roadmap to Decipher and Combat Challenges in Human Health and Disease?

MicroRNAs are small non-coding RNA (18–24 nt long) that fine-tune gene expression at the post-transcriptional level. With the advent of “multi-omics” analysis and sequencing approaches, they have now been implicated in every facet of basic molecular networks, including metabolism, homeostasis, and cell survival to aid cellular machinery in adapting to changing environmental cues. Many animals must endure harsh environmental conditions in nature, including cold/freezing temperatures, oxygen limitation (anoxia/hypoxia), and food or water scarcity, often requiring them to revamp their metabolic organization, frequently on a seasonal or life stage basis. MicroRNAs are important regulatory molecules in such processes, just as they are now well-known to be involved in many human responses to stress or disease. The present review outlines the role of miRNAs in natural animal models of environmental stress and adaptation including torpor/hibernation, anoxia/hypoxia tolerance, and freeze tolerance. We also discuss putative medical applications of advances in miRNA biology including organ preservation for transplant, inflammation, ageing, metabolic disorders (e.g., obesity), mitochondrial dysfunction (mitoMirs) as well as specialized miRNA subgroups respective to low temperature (CryomiRs) and low oxygen (OxymiRs). The review also covers differential regulation of conserved and novel miRNAs involved at cell, tissue, and stress specific levels across multiple species and their roles in survival. Ultimately, the species-specific comparison and conserved miRNA responses seen in evolutionarily disparate animal species can help us to understand the complex miRNA network involved in regulating and reorganizing metabolism to achieve diverse outcomes, not just in nature, but in human health and disease.

The effect of perceived social support on psychological resilience in liver transplant patients receiving immunosuppression therapy

OBJECTIVE

This study was conducted to investigate the effect of social support on psychological resilience in liver transplant patients receiving immunosuppression therapy.

METHOD

This study was carried out as a descriptive and cross-sectional study with the participation of 290 liver transplant patients hospitalized in the liver transplant center of a research and application hospital. Personal Information Form, Multidimensional Scale of Perceived Social Support (MSPSS) and Brief Resilience Scale (BRS) were used in data collection. The data analysis was performed with IBM Statistical Package for the Social Sciences Statistics 25.

RESULTS

According to the data obtained, it was determined that 30.4% of the patients were 58 years old and over, 81% of them were male and 92.8% of them were married. It was found that all of the patients used antimetabolites and corticosteroids, and 82.8% of them used calcineurin inhibitors. It was determined that 32.8% of the patients experienced infection, neuropsychiatric problems and nephrotoxicity at the same time. The psychological resilience of the patients was found to be moderate, and their perceived social support was found to be low.

CONCLUSION

It is not always possible for liver transplant patients to deal with their situation effectively. The psychological resilience and social support levels of patients who have undergone liver transplantation should be noticed, and social, economic and psychological support should be provided.

The effect of immunosuppression therapy on activities of daily living and comfort level after liver transplantation

OBJECTIVES

This study was carried out to investigate the effect of immunosuppression therapy on activities of daily living and comfort level after liver transplantation.

MATERIALS AND METHODS

This study was conducted in a descriptive and correlational type with the participation of 148 liver transplant patients hospitalized in the liver transplant center of a university hospital. Personal Information Form, Katz Activities of Daily Living Scale and General Comfort Questionnaire were used in data collection. The data analysis was performed with IBM SPSS (Statistical Package for the Social Sciences) Statistics 25.

RESULTS

According to the results obtained from the study, it was determined that 31.1% of the patients were 58 years old and over, 20.9% of them were between 48- and 57 years old, and 81.8% of them were male. It was found that 61.5% of the patients were between the 11th and 21st days after transplantation and 26.4% of them were given oxygen with a non-invasive catheter. It was determined that the patients were semi-independent in activities of daily living and had a moderate comfort level.

CONCLUSIONS

It is not always possible for liver transplant patients to effectively deal with their condition. The low comfort level and quality of life of patients who have undergone liver transplantation should be noticed, and social, economic and psychological support should be provided.

Novel severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) infection: Microbiologic perspectives and anatomic considerations for sanctuary sites

Introduction

A significant chunk of global life – the economy, sports, aviation, academic, and entertainment activities – has significantly been affected by the ravaging outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) with devastating consequences on morbidity and mortality in many countries of the world.

Methods

This review utilized search engines such as google scholar, PubMed, ResearchGate, and web of science to retrieve articles and information using keywords like “Coronavirus”, “SARS-CoV-2”, “COVID-19”, “Origin of coronavirus and SARS-CoV-2”, “microbiology of coronavirus”, “microbiology of SARS-CoV-2”, COVID-19”, “Coronavirus reservoir sites”, “Anatomic sanctuary sites and SARS-CoV-2”, biological barriers and coronavirus”, biological barrier and SARS-CoV-2”.

Results

While this pandemic has caught the global scientific community at its lowest level of preparedness, it has inadvertently created a unified and wholesome approach towards developing potential vaccine (s) candidates by escalating clinical trial protocols in many countries of Europe, China and the United States. Interestingly, viral pathobiology continues to be an evolving aspect that potentially shows that the management of the current outbreak may largely depend on the discovery of a vaccine as the administration of known antiviral drugs are proving to offer some respite. Unfortunately, discontinuation and longtime administration of these drugs have been implicated in endocrine, reproductive and neurological disorders owing to the development of pathological lesions at anatomical sanctuary sites such as the brain and testis, as well as the presence of complex biological barriers that permit the entry of viruses but selective to the entrance of chemical substances and drugs.

Conclusion

This review focuses on the microbiologic perspectives and importance of anatomical sanctuary sites in the possible viral rebound or reinfection into the system and their implications in viral re-entry and development of reproductive and neurological disorders in COVID-19 patients.

Clinical Application of Human Induced Pluripotent Stem Cell-Derived Organoids as an Alternative to Organ Transplantation

Transplantation is essential and crucial for individuals suffering from end-stage organ failure diseases. However, there are still many challenges regarding these procedures, such as high rates of organ rejection, shortage of organ donors, and long waiting lines. Thus, investments and efforts to develop laboratory-grown organs have increased over the past years, and with the recent progress in regenerative medicine, growing organs in vitro might be a reality within the next decades. One of the many different strategies to address this issue relies on organoid technology, a miniaturized and simplified version of an organ. Here, we address recent progress on organoid research, focusing on transplantation of intestine, retina, kidney, liver, pancreas, brain, lung, and heart organoids. Also, we discuss the main outcomes after organoid transplantation, common challenges faced by these promising regenerative medicine approaches, and future perspectives on the field.

Polyphenols and neurodegenerative diseases: focus on neuronal regeneration

Neurodegenerative diseases are questions that modern therapeutics can still not answer. Great milestones have been achieved regarding liver, heart, skin, kidney and other types of organ transplantations but the greatest drawback is the adequate supply of these organs. Furthermore, there are still a few options available in the treatment of neurodegenerative diseases. With great advances in medical science, many health problems faced by humans have been solved, and their quality of life is improving. Moreover, diseases that were incurable in the past have now been fully cured. Still, the area of regenerative medicine, especially concerning neuronal regeneration, is in its infancy. Presently allopathic drugs, surgical procedures, organ transplantation, stem cell therapy forms the core of regenerative therapy. However, many times, the currently used therapies cannot completely cure damaged organs and neurodegenerative diseases. The current review focuses on the concepts of regeneration, hurdles faced in the path of regenerative therapy, neurodegenerative diseases and the idea of using peptides, cytokines, tissue engineering, genetic engineering, advanced stem cell therapy, and polyphenolic phytochemicals to cure damaged tissues and neurodegenerative diseases.

Current standards and ethical landscape of engineered tissues-3D bioprinting perspective

Tissue engineering is an evolving multi-disciplinary field with cutting-edge technologies and innovative scientific perceptions that promise functional regeneration of damaged tissues/organs. Tissue engineered medical products (TEMPs) are biomaterial-cell products or a cell-drug combination which is injected, implanted or topically applied in the course of a therapeutic or diagnostic procedure. Current tissue engineering strategies aim at 3D printing/bioprinting that uses cells and polymers to construct living tissues/organs in a layer-by-layer fashion with high 3D precision. However, unlike conventional drugs or therapeutics, TEMPs and 3D bioprinted tissues are novel therapeutics and need different regulatory protocols for clinical trials and commercialization processes. Therefore, it is essential to understand the complexity of raw materials, cellular components, and manufacturing procedures to establish standards that can help to translate these products from bench to bedside. These complexities are reflected in the regulations and standards that are globally in practice to prevent any compromise or undue risks to patients. This review comprehensively describes the current legislations, standards for TEMPs with a special emphasis on 3D bioprinted tissues. Based on these overviews, challenges in the clinical translation of TEMPs & 3D bioprinted tissues/organs along with their ethical concerns and future perspectives are discussed.

Generation of bioartificial hearts using decellularized scaffolds and mixed cells

BACKGROUND

Patients with end-stage heart failure must receive treatment to recover cardiac function, and the current primary therapy, heart transplantation, is plagued by the limited supply of donor hearts. Bioengineered artificial hearts generated by seeding of cells on decellularized scaffolds have been suggested as an alternative source for transplantation. This study aimed to develop a tissue-engineered heart with lower immunogenicity and functional similarity to a physiological heart that can be used for heart transplantation.

MATERIALS AND METHODS

We used sodium dodecyl sulfate (SDS) to decellularize cardiac tissue to obtain a decellularized scaffold. Mesenchymal stem cells (MSCs) were isolated from rat bone marrow and identified by flow cytometric labeling of their surface markers. At the same time, the multi-directional differentiation of MSCs was analyzed. The MSCs, endothelial cells, and cardiomyocytes were allowed to adhere to the decellularized scaffold during perfusion, and the function of tissue-engineered heart was analyzed by immunohistochemistry and electrocardiogram.

RESULTS

MSCs, isolated from rats differentiated into cardiomyocytes, were seeded along with primary rat cardiomyocytes and endothelial cells onto decellularized rat heart scaffolds. We first confirmed the pluripotency of the MSCs, performed immunostaining against cardiac markers expressed by MSC-derived cardiomyocytes, and completed surface antigen profiling of MSC-derived endothelial cells. After cell seeding and culture, we analyzed the performance of the bioartificial heart by electrocardiography but found that the bioartificial heart exhibited abnormal electrical activity. The results indicated that the tissue-engineered heart lacked some cells necessary for the conduction of electrical current, causing deficient conduction function compared to the normal heart.

CONCLUSION

Our study suggests that MSCs derived from rats may be useful in the generation of a bioartificial heart, although technical challenges remain with regard to generating a fully functional bioartificial heart.

Immunogenicity analysis of decellularized cardiac scaffolds after transplantation into rats

Aim: Cardiac extracellular matrix (cECM) scaffolds are promising biomaterials for clinical applications. Our aim is to determine the immunogenicity of decellularized scaffolds from different sources for use as artificial organs during organ transplantation. Materials & methods: We transplanted Lewis rats with syngeneic (Lewis rat cECM), allogeneic (BN rat cECM) or xenogeneic (hamster cECM) decellularized cardiac scaffolds. Acute vascular and cellular rejection was quantified by immunohistochemistry and immune cell infiltration. Results: BN rat and hamster hearts were rejected following transplantation. BN and hamster cECMs had similarly low immunogenicity compared with Lewis rat cECMs and did not lead to increased rejection. Conclusion: We found that scaffolds from all sources did not induce vascular or cellular rejection and exhibited low immunogenicity.

Immunosuppression following organ transplantation. Part 1: mechanisms and immunosuppressive agents

Solid organ transplantation has revolutionised medical care by providing a definitive cure for a wide spectrum of end-stage medical conditions. This treatment, however, does not come without complications and poses the risks of rejection, life-threatening infection, malignancies and recurrent organ failure, with significant impacts on patient outcomes. One of the major challenges involved in optimising post-transplant outcomes is managing the immune system's response to the transplanted graft and preventing organ rejection. This is mainly accomplished through the use of immunosuppressant agents, which have become a mainstay of treatment for a majority of post-transplant patients. This article, the first of two parts, discusses the concept of immunosuppression and its importance in the care of patients who have received an organ transplant. It focuses on the pathophysiologic mechanisms involved in transplant rejection and discusses the pharmacologic aspects of immunosuppression and its implications for patient care.