Organ shortage crisis: problems and possible solutions

From Referral to Consent: Unveiling Racial Disparities at Critical Stages of Pediatric Organ Donation

BACKGROUND

Organ transplantation is the gold standard for treating end-stage organ failure, improving survival and quality of life. Despite efforts to address racial and ethnic disparities, these disparities persist, with their impact on the pediatric organ donation process remaining unclear.

METHODS

This is a retrospective review of the Organ Retrieval and Collection of Health Information for Donation (ORCHID) database version 2.0.0, from 01/01/2015 to 12/31/2021. All patients referred younger than 18 years were included.

RESULTS

A total of 4528 referred patients were identified, with a median age at referral of 3.0[IQR: 0.0-13.0] years. Of these, 1862 (41%) were female, 2000 (44%) were White Non-Hispanic, and 916 (20%) had a confirmed diagnosis of brain death at referral. OPO 1 accounted for 1523 (33%) referrals, and accidents were the leading cause of death (n = 1175, 26%). Next-of-kin were approached for organ donation in 1344 (30%) cases. After adjustment, when compared to White Non-Hispanic, next-of-kin for Hispanic (OR: 0.69;95% CI: 0.54-0.89, p = 0.005), Black (OR: 0.55;95% CI: 0.42-0.72, p < 0.001) and "Other"(OR: 0.64;95% CI: 0.43-0.96, p = 0.031) race patients were less likely to be approached. Among the approached next-of-kin, 819 (61%) consented to organ donation. Adjusted analyses demonstrated that, compared to White Non-Hispanic patients, next-of-kin for Hispanic (OR: 0.63;95% CI: 0.44-0.89; p = 0.010), Black (OR: 0.31;95% CI: 0.22-0.43, p < 0.001), and "Other"(OR: 0.37;95% CI: 0.20-0.66, p < 0.001) race patients were significantly less likely to consent.

CONCLUSIONS

This study highlights the low approach rates for potential organ donors and the persistent racial disparities in the pediatric deceased organ donation process. Racial minority groups are less likely to be approached for donation and to provide consent compared to White individuals. These findings underscore the need for an equitable organ donation process to expand the pediatric donor pool.

Advanced supramolecular hydrogels and their applications in the formulation of next-generation bioinks for tissue engineering: A review

Supramolecular hydrogels are three-dimensional structures composed of cross-linked macromolecules interconnected by dynamic physical bonds, which allow them to absorb and retain significant volumes of water. Their intrinsic properties, such as viscoelasticity, self-healing capabilities, and high water content, render them promising materials for cell-laden scaffolds utilized in bioinks. This review systematically summarizes the current state-of-the-art advancements in hydrogels for tissue engineering, categorizing them based on the nature of their supramolecular interactions. Particular emphasis is placed on the classification of supramolecular hydrogels and their associated properties, including kinetics, mechanical characteristics, responsiveness, and swelling behavior. The review specifically addresses the criteria that hydrogels must fulfill prior to their application in bioinks. Achieving biocompatibility and bioactivity necessitates the careful selection of hydrogel compositions with suitable properties, as well as the incorporation of external organic or inorganic bioactive molecules. Methods for measuring and enhancing biophysical and biochemical properties are discussed in detail, alongside an exploration of the unique requirements of bioinks tailored for each additive manufacturing method. This review paper serves as an instructive resource for the construction and characterization of supramolecular hydrogels, facilitating their application in bioinks for tissue engineering.

Understanding Alcohol Abuse in Deceased Donors: Effects on Liver Transplant Results

Background/Objectives: Liver transplantation is a life-saving procedure for patients with end-stage liver disease. In recent years, the demand for liver transplantation has surpassed the supply of available donor organs. Utilizing extended-criteria donors (ECDs) alleviates the scarcity of suitable donor livers for transplantation. One of the ECD was donors with a history of alcohol abuse. Liver grafts from donors with a history of chronic and active alcohol abuse are typically promptly excluded, diminishing the available organ pool. This highlights the need to re-evaluate the donor exclusion criteria and expand the organ pool to address the ongoing shortage. Methods: We examined adult (>18 years) liver transplant recipients who received deceased donor livers and had a documented history of alcohol abuse between 2011 and 2024. Liver transplant indications were conventional and included hepatitis C virus (HCV), non-alcoholic steatohepatitis, alcoholic liver disease, alcoholic liver disease coexisting with HCV, cryptogenic cirrhosis, chronic cholestatic liver disease, primary biliary cholangitis, primary sclerosing cholangitis, metabolic liver disease, hepatocellular carcinoma, and alcoholic hepatitis. We compared the 1-year, 5-year, and 9-year survival rates with those of liver recipients from non-alcohol-consuming donors. Results: In total, 370 liver recipients from deceased donors with a documented history of alcohol abuse were included. At 1 year post-transplant, survival was comparable between the two groups. Conclusions: Liver transplantation from deceased donors with a history of alcohol abuse yielded survival rates and liver function outcomes comparable to those from non-alcohol-using donors. By expanding the criteria to include carefully screened alcohol-using donors, transplant programs can improve access to life-saving transplantations.

From gift to mutilation: Exploring nursing Students' metaphorical conceptions of organ donation: A qualitative study

BACKGROUND

Understanding nursing students' perspectives on organ donation is essential to foster positive attitudes and increase donation rates.

OBJECTIVE

This study aimed to uncover the metaphors used by nursing students to describe organ donation, revealing their underlying perceptions and beliefs.

DESIGN

A qualitative metaphor analysis study.

METHODS

This study was conducted at Burdur Mehmet Akif Ersoy University, Bucak Health College with 318 nursing students in Turkey. Data were collected through written responses and analyzed using metaphor analysis. The surveys, composed of open-ended questions to elicit nursing students' metaphors of organ donation, were distributed to the participants. The collected data were named, classified, and categorized.

RESULTS

In this study, students produced 311 valid metaphors related to organ donation. The metaphors revealing the students' perceptions of the concept of organ donation were grouped under 10 categories. Nursing students in this study expressed both positive metaphorical concepts, such as 'gift box,' 'rainbow bridge,' 'Candle in the dark,' and 'new beginning,' as well as negative metaphorical concepts, such as 'soldier on the battlefield,' 'heavy load,' and 'disfigurement' associated with organ donation.

CONCLUSION

The findings reveal a wide spectrum of metaphorical perceptions among nursing students, ranging from highly positive to very negative. This variability underscores the need for targeted educational strategies to address divergent attitudes and misconceptions, fostering more consistent and informed perspectives on organ donation in nursing education.

From Promise to Practice: Recent Growth in 30 Years of Tissue Engineering Commercialization

This perspective, marking the 30th anniversary of the Tissue Engineering journal, discusses the exciting trends in the global commercialization of tissue engineering technology. Within a historical context, we present an evolution of challenges and a discussion of the last 5 years of global commercial successes and emerging market trends, highlighting the continued expansion of the field in the northeastern United States. This leads to an overview of the last 5 years' progress in clinical trials for tissue-engineered therapeutics, including an analysis of trends in success and failure. Finally, we provide a broad overview of preclinical research and a perspective on where the state-of-the-art lies on the horizon.

Surveillance and prevention of infection in clinical xenotransplantation

SUMMARYXenotransplantation, the transplantation of living organs, tissues, or cells between species, carries the potential to address the global shortage of human organs for patients with end-stage organ failure. Recent advances in genetic engineering have improved prospects for clinical xenotransplantation by reducing immune and inflammatory responses to grafts, controlling coagulation on endothelial surfaces, and modifying viral risks, including the porcine endogenous retrovirus (PERV). Management of infectious risks posed by clinical xenotransplantation requires meticulous attention to the biosecure breeding and microbiological surveillance of source animals and recipients and consideration of novel infection control requirements. Infectious risks in xenotransplantation stem from both known human pathogens in immunosuppressed transplant recipients and from porcine organisms for which the clinical manifestations, microbial assays, and therapies are generally limited. Both known and unknown zoonoses may be transmitted from pigs to humans. Some pig-specific pathogens do not infect human cells but have systemic manifestations when active within the xenograft, including porcine cytomegalovirus/porcine roseolovirus (PCMV/PRV), which contributes to graft rejection and consumptive coagulopathy. The role of porcine endogenous retrovirus (PERV) in humans remains uncertain despite the absence of documented transmissions and the availability of swine with inactivated genomic PERV. New technologies, such as metagenomic sequencing and multi-omics approaches, will be essential for detection of novel infections and for understanding interactions between the xenograft, the host's immune system, and potential pathogens. These approaches will allow development of infection control protocols, pathogen surveillance requirements, and tailored antimicrobial therapies to enhance the safety and success of clinical xenotransplantation.

Outcomes of Kidney Transplantation From Donors on Renal Replacement Therapy

Background

The increasing demand for organs has pushed transplant providers to expand kidney acceptance criteria. The use of kidneys from donors with AKI has been shown to provide good long-term graft survival. We aim to evaluate and compare the outcomes of deceased donor kidney transplantation from donors with acute kidney injury (AKI), either with or without renal replacement therapy (AKI-RRT) before donation.

Methods

A single-center retrospective review of all patients who underwent deceased donor kidney transplantation from AKI donors between 2009 and 2020 was performed. AKI donors were defined on the basis of donor terminal creatinine ≥2.0 mg/dL or use of RRT before donation. We compared the outcomes of recipients receiving a kidney from a donor with AKI versus AKI-RRT. Data are presented as medians (interquartile ranges) and numbers (percentages).

Results

Four hundred ninety-six patients were identified, of whom 300 (60.4%) were men with a median age of 57 y at transplantation. Thirty-nine patients received an AKI-RRT, whereas 457 received an AKI kidney. Donors in the AKI-RRT group were younger (28 versus 40), had less incidence of hypertension (15.3% versus 31.9%), and were more likely to be imported (94.9% versus 76.8%). There was a higher incidence of delayed graft function (72% versus 44%, P < 0.001) in the AKI-RRT group. Recipients in both groups had similar 90-d (100% versus 95.2%) and 1-y (100% versus 91.9%) graft survival. With a median follow-up of 5 y, there was no difference in death-censored graft survival in both groups (P = 0.83).

Conclusions

Careful selection of kidneys from donors with AKI on RRT can be safely used for kidney transplantation with favorable clinical outcomes.

Attitudes Toward Renal Xenotransplantation in a Muslim Country: Analysis of Specific Subgroups

Renal transplantation is the optimal treatment for end-stage kidney disease, but the rising demand for organs necessitates exploring alternative graft sources, including xenotransplantation. This study evaluated attitudes toward xenotransplantation among different social groups in a Muslim country. A structured survey assessing demographics, religiosity levels, attitudes toward xenotransplantation, and the influence of religious authorities was completed by 988 participants: 376 clergy members (38.1%), 206 physicians (20.9%), 162 dialysis patients and their relatives (16.4%), and 244 individuals from other groups (24.7%). Significant sociodemographic differences were observed in gender, marital status, and education (p < 0.001). Physicians and dialysis patients/relatives were likelier to support living donor transplantation (48.5%, 67.3%), whereas clergy members often reported no opinion (44.9%). Favorable attitudes toward xenotransplantation were the highest among physicians (66%) and dialysis patients/relatives (67.3%). When the animal was specified as a pig, 73.1% of the Clergy group exhibited unfavorable attitudes. However, this group significantly changed their opinion after the favorable fatwa issued by the religious authority. Logistic regression identified male gender, lower religiosity, and higher education as predictors of favorable attitudes, with physicians and dialysis patients/relatives demonstrating the strongest associations compared to clergy. To infer, collaboration between religious and scientific authorities is essential to address concerns and emphasize the potential benefits of xenotransplantation.

Bioengineering of a human iPSC-derived vascularized endocrine pancreas for type 1 diabetes

Intrahepatic islet transplantation in patients with type 1 diabetes is limited by donor availability and lack of engraftment. Alternative β cell sources and transplantation sites are needed. We demonstrate the feasibility to repurpose a decellularized lung as an endocrine pancreas for β cell replacement. We bioengineer an induced pluripotent stem cell (iPSC)-based version, fabricating a human iPSC-based vascularized endocrine pancreas (iVEP) using iPSC-derived β cells (iPSC-derived islets [SC-islets]) and endothelial cells (iECs). SC-islets and iECs are aggregated into vascularized iβ spheroids (ViβeSs), and over 7 days of culture, spheroids integrate into the bioengineered vasculature, generating a functional, perfusable human endocrine organ. In vitro, the vascularized extracellular matrix (ECM) sustained SC-islet engraftment and survival with a significantly preserved β cell mass and a physiologic insulin release. In vivo, iVEP restores normoglycemia in diabetic NSG mice. We report a human iVEP providing a controlled in vitro insulin-secreting phenotype and in vivo function.

Perspectives and Tools in Liver Graft Assessment: A Transformative Era in Liver Transplantation

Liver transplantation is a critical and evolving field in modern medicine, offering life-saving treatment for patients with end-stage liver disease and other hepatic conditions. Despite its transformative potential, transplantation faces persistent challenges, including a global organ shortage, increasing liver disease prevalence, and significant waitlist mortality rates. Current donor evaluation practices often discard potentially viable livers, underscoring the need for refined graft assessment tools. This review explores advancements in graft evaluation and utilization aimed at expanding the donor pool and optimizing outcomes. Emerging technologies, such as imaging techniques, dynamic functional tests, and biomarkers, are increasingly critical for donor assessment, especially for marginal grafts. Machine learning and artificial intelligence, exemplified by tools like LiverColor, promise to revolutionize donor-recipient matching and liver viability predictions, while bioengineered liver grafts offer a future solution to the organ shortage. Advances in perfusion techniques are improving graft preservation and function, particularly for donation after circulatory death (DCD) grafts. While challenges remain-such as graft rejection, ischemia-reperfusion injury, and recurrence of liver disease-technological and procedural advancements are driving significant improvements in graft allocation, preservation, and post-transplant outcomes. This review highlights the transformative potential of integrating modern technologies and multidisciplinary approaches to expand the donor pool and improve equity and survival rates in liver transplantation.

Numerical modeling of oxygen diffusion in tissue spheroids undergoing fusion using function representation and finite volumes

A three-dimensional cell culture called a spheroid serves as a foundational entity in a wide variety of modern tissue engineering applications, including 3D-bioprinting and preclinical drug testing. Lack of oxygen within tissue spheroids hinders metabolism of cells and eventually leads to cell death. Prevention of necrosis is crucial to success of tissue engineering methods and such prevention requires estimation of cell viability in the spheroid. We propose a novel approach for numerical modeling of diffusion in tissue spheroids during their fusion. The approach is based on numerical solutions of partial differential equations and the application of Function Representation (FRep) framework for geometric modeling. We present modeling of oxygen diffusion based on meshes derived from the geometry of fusing spheroids, a method for selecting optimal spheroid size, and several statistics for estimating cellular viability. Our findings provide insights into oxygen diffusion in three-dimensional cell cultures thus improving the robustness of biotechnological methods that employ tissue spheroids.

Aerogels Based on Chitosan and Collagen Modified with Fe2O3 and Fe3O4 Nanoparticles: Fabrication and Characterization

The necessity to mitigate the intrinsic issues associated with tissue or organ transplants, in order to address the rising prevalence of diseases attributable to increased life expectancy, provides a rationale for the pursuit of innovation in the field of biomaterials. Specifically, biopolymeric aerogels represent a significant advancement in the field of tissue engineering, offering a promising solution for the formation of temporary porous matrices that can replace damaged tissues. However, the functional characteristics of these materials are inadequate, necessitating the implementation of matrix reinforcement methods to enhance their performance. In this study, chemical and green iron oxide nanoparticles, previously synthesized and documented in existing research, were incorporated into hybrid aerogels combining collagen (C) and chitosan (CH). The characterization of these aerogels was conducted through rheological, microstructural, and functional analyses. The results demonstrate that the incorporation of iron oxide nanoparticles has a significant influence on the properties of the aerogels fabricated with them. In particular, the incorporation of these nanoparticles has been observed to modify the mechanical properties, with an increase in strength and porosity that may support cell proliferation.

The Promise and Challenges of Bioprinting in Tissue Engineering

Organ transplantation, biomimetic organ models, and the restoration of damaged or eviscerated tissues have been key goals in surgical and medical research since their inception [...].

Engineering considerations in the design of tissue specific bioink for 3D bioprinting applications

Over eight million surgical procedures are conducted annually in the United Stats to address organ failure or tissue losses. In response to this pressing need, recent medical advancements have significantly improved patient outcomes, primarily through innovative reconstructive surgeries utilizing tissue grafting techniques. Despite tremendous efforts, repairing damaged tissues remains a major clinical challenge for bioengineers and clinicians. 3D bioprinting is an additive manufacturing technique that holds significant promise for creating intricately detailed constructs of tissues, thereby bridging the gap between engineered and actual tissue constructs. In contrast to non-biological printing, 3D bioprinting introduces added intricacies, including considerations for material selection, cell types, growth, and differentiation factors. However, technical challenges arise, particularly concerning the delicate nature of living cells in bioink for tissue construction and limited knowledge about the cell fate processes in such a complex biomechanical environment. A bioink must have appropriate viscoelastic and rheological properties to mimic the native tissue microenvironment and attain desired biomechanical properties. Hence, the properties of bioink play a vital role in the success of 3D bioprinted substitutes. This review comprehensively delves into the scientific aspects of tissue-centric or tissue-specific bioinks and sheds light on the current challenges of the translation of bioinks and bioprinting.

Outcomes Using High KDPI Kidneys in Recipients Over 65 y of Age

BACKGROUND

Kidney transplantation has been shown to improve life expectancy when compared with remaining on dialysis. However, there is an ever-expanding shortage of available organs for transplantation. The use of high kidney donor profile index (KDPI; >85) kidneys is 1 strategy to address this shortage. The current study aims to evaluate the advantage of accepting a high KDPI versus a low KDPI kidney (KDPI ≤85) in patients 65 y or older.

METHODS

A single-center retrospective review of all patients, ages 65 y or older, who underwent deceased donor kidney transplantation between 2010 and 2020 was performed. Outcomes and wait times of recipients undergoing low KDPI (KDPI ≤85) versus high KDPI (KDPI >85) kidney transplantation were compared. Significance was defined as P < 0.05.

RESULTS

Four hundred ninety-two patients were identified; 317 (64.4%) were men with a median age at transplantation of 69 y. Four hundred five patients received low KDPI kidneys, whereas the remaining received high KDPI grafts. High KDPI kidneys were procured from older donors (60 versus 47, P < 0.001) and had shorter cold ischemic time (25.0 versus 28.3 h, P = 0.01) compared with low KDPI kidneys. There was no significant difference in graft and patient survival between low and high KDPI recipients, with 85.1% and 86.2% grafts functioning at a follow-up of 4.85 (2.9-7.0) y, respectively. Pretransplant wait time was significantly shorter in the high KDPI group (2.7 [1.8-4.1] versus 3.5 [2.3-4.8] y; P = 0.004).

CONCLUSIONS

In patients 65 y or older undergoing deceased donor kidney transplantation, high KDPI kidneys may offer shorter pretransplant waiting times without compromising graft or patient survival.

Fibrin Hydrogels Reinforced by Reactive Microgels for Stimulus-Triggered Drug Administration

Tissue engineering is a steadily growing field of research due to its wide-ranging applicability in the field of regenerative medicine. Application-dependent mechanical properties of a scaffold material as well as its biocompatibility and tailored functionality represent particular challenges. Here the properties of fibrin-based hydrogels reinforced by functional cytocompatible poly(N-vinylcaprolactam)-based (PVCL) microgels are studied and evaluated. The employment of temperature-responsive microgels decorated by epoxy groups for covalent binding to the fibrin is studied as a function of cross-linking degree within the microgels, microgel concentration, as well as temperature. Rheology reveals a strong correlation between the mechanical properties of the reinforced fibrin-based hydrogels and the microgel rigidity and concentration. The incorporated microgels serve as cross-links, which enable temperature-responsive behavior of the hydrogels, and slow down the hydrogel degradation. Microgels can be additionally used as carriers for active drugs, as demonstrated for dexamethasone. The microgels' temperature-responsiveness allows for triggered release of payload, which is monitored using a bioassay. The cytocompatibility of the microgel-reinforced fibrin-based hydrogels is demonstrated by LIVE/DEAD staining experiments using human mesenchymal stem cells. The microgel-reinforced hydrogels are a promising material for tissue engineering, owing to their superior mechanical performance and stability, possibility of drug release, and retained biocompatibility.

What determinants impact deceased organ donation consent in the adult intensive care unit? An integrative review exploring the perspectives of staff and families

BACKGROUND

Deceased organ donation saves lives. Donation processes in New Zealand operate under an opt-in system, which requires consent from families of patients diagnosed with brain death or circulatory death while in the intensivecare unit. The donation demand and supply mismatch is a global phenomenon.

OBJECTIVES

The objective of this study was to understand the determinants of deceased organ donation decisions in the adult intensive care setting from the perspectives of staff and families.

METHODS

An integrative review based on Whittemore and Knafl's approach searched literature through databases CINAHL Plus, SCOPUS, Proquest Medline Ovid, and manual ancestry searches. Inclusion/exclusion criteria screened for pertinent literature, which were reported using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Selected studies were appraised using a generic scoring tool, and data were systematically extracted and coded onto spreadsheets using inductive, thematic analysis.

RESULTS

A total of 21 studies (12 qualitative, seven quantitative, two mixed methods) were included. Publication dates ranged from 1993 to 2021 from multiple countries (18 opt-in, three opt-out systems). Four overarching themes pertaining to families and staff were generated. Important knowledge related to families' knowledge deficits around brain death, the purpose of ventilation, donation procedures, patients' wishes, and staffs' lack of training. Challenging communication highlighted miscommunications due to language choices and interrupted continuity of care during staff-family interactions. Internal determinants explored the cultural, spiritual, and emotional perspectives of families, while staff faced a sense of burden and conflicting values in delivering care between donors and recipients. External determinants related to the clinical environment impacting on grieving families, while for the staff, it explained concerns around resources and organisational processes.

CONCLUSIONS

Factors underpinning deceased organ donation are multifaceted and complex. Staff actions and families' decisions are inextricably intertwined. Modifiable factors include a lack of formal training and communicational skills and environmental limitations of an intensive care setting.

Biomaterials for extrusion-based bioprinting and biomedical applications

Amongst the range of bioprinting technologies currently available, bioprinting by material extrusion is gaining increasing popularity due to accessibility, low cost, and the absence of energy sources, such as lasers, which may significantly damage the cells. New applications of extrusion-based bioprinting are systematically emerging in the biomedical field in relation to tissue and organ fabrication. Extrusion-based bioprinting presents a series of specific challenges in relation to achievable resolutions, accuracy and speed. Resolution and accuracy in particular are of paramount importance for the realization of microstructures (for example, vascularization) within tissues and organs. Another major theme of research is cell survival and functional preservation, as extruded bioinks have cells subjected to considerable shear stresses as they travel through the extrusion apparatus. Here, an overview of the main available extrusion-based printing technologies and related families of bioprinting materials (bioinks) is provided. The main challenges related to achieving resolution and accuracy whilst assuring cell viability and function are discussed in relation to specific application contexts in the field of tissue and organ fabrication.

Blood vessels in a dish: the evolution, challenges, and potential of vascularized tissues and organoids

Vascular pathologies are prevalent in a broad spectrum of diseases, necessitating a deeper understanding of vascular biology, particularly in overcoming the oxygen and nutrient diffusion limit in tissue constructs. The evolution of vascularized tissues signifies a convergence of multiple scientific disciplines, encompassing the differentiation of human pluripotent stem cells (hPSCs) into vascular cells, the development of advanced three-dimensional (3D) bioprinting techniques, and the refinement of bioinks. These technologies are instrumental in creating intricate vascular networks essential for tissue viability, especially in thick, complex constructs. This review provides broad perspectives on the past, current state, and advancements in key areas, including the differentiation of hPSCs into specific vascular lineages, the potential and challenges of 3D bioprinting methods, and the role of innovative bioinks mimicking the native extracellular matrix. We also explore the integration of biophysical cues in vascularized tissues in vitro, highlighting their importance in stimulating vessel maturation and functionality. In this review, we aim to synthesize these diverse yet interconnected domains, offering a broad, multidisciplinary perspective on tissue vascularization. Advancements in this field will help address the global organ shortage and transform patient care.

Living Organ Donation for Transplantation in Bangladesh: Reality and Problems

The stipulation of living organ transplantation policy and practice in Bangladesh is family-oriented, with relatives being the only people legally eligible to donate organs. There have been very few transplantations of bone marrows, liver lobes, and kidneys from related-living donors in Bangladesh. The major question addressed in this study is why Bangladesh is not getting adequate organs for transplantation. In this study, I examin the stipulations of the policy and practice of living organ donation through the lens of 32 key stakeholders including physicians and nurses, a health administrator, organ donors and recipients, and their family members, as they can shed light on the realities and problems of organ donation for transplantation in Bangladesh. My ethnography reveals that the family members are always encouraged to donate organs for transplantation, and saving the lives of relatives through organ donation is seen as a moral obligation. Many view saving the life of a relative by donating one's organs as equivalent to saving one's own life. An assessment of the dynamics of biomedicine, religion, and culture leads to the conclusion that the family-oriented organ donation policy and practice have been widely endorsed and accepted in Bangladesh, and Islamic ethical principles and collective family ethos undergird that policy and practice. However, the unavailability of medical resources, lack of post-operative coverage for organ donors, religious misconceptions and unawareness of the general public, and the absence of posthumously donated vital organs for transplantation are perceived to be the most common barriers to a successful living donor-recipient pair organ transplantation. By overcoming these obstacles, Bangladesh can develop a successful living donor-recipient pair organ transplantation program that will ensure improved healthcare outcomes, promote altruism and solidarity among Bangladeshi families, and protect the poor from having their organs sold to wealthy patients.

Considerations for the use of porcine organ donation models in preclinical organ donor intervention research

Use of animal models in preclinical transplant research is essential to the optimization of human allografts for clinical transplantation. Animal models of organ donation and preservation help to advance and improve technical elements of solid organ recovery and facilitate research of ischemia-reperfusion injury, organ preservation strategies, and future donor-based interventions. Important considerations include cost, public opinion regarding the conduct of animal research, translational value, and relevance of the animal model for clinical practice. We present an overview of two porcine models of organ donation: donation following brain death (DBD) and donation following circulatory death (DCD). The cardiovascular anatomy and physiology of pigs closely resembles those of humans, making this species the most appropriate for pre-clinical research. Pigs are also considered a potential source of organs for human heart and kidney xenotransplantation. It is imperative to minimize animal loss during procedures that are surgically complex. We present our experience with these models and describe in detail the use cases, procedural approach, challenges, alternatives, and limitations of each model.

Efficacy of Engraftment and Safety of Human Umbilical Di-Chimeric Cell (HUDC) Therapy after Systemic Intraosseous Administration in an Experimental Model

Cell-based therapies hold promise for novel therapeutic strategies in regenerative medicine. We previously characterized in vitro human umbilical di-chimeric cells (HUDCs) created via the ex vivo fusion of human umbilical cord blood (UCB) cells derived from two unrelated donors. In this in vivo study, we assessed HUDC safety and biodistribution in the NOD SCID mouse model at 90 days following the systemic intraosseous administration of HUDCs. Twelve NOD SCID mice (n = 6/group) received intraosseous injection of donor UCB cells (3.0 × 106) in Group 1, or HUDCs (3.0 × 106) in Group 2, without immunosuppression. Flow cytometry assessed hematopoietic cell surface markers in peripheral blood and the presence of HLA-ABC class I antigens in lymphoid and non-lymphoid organs. HUDC safety was assessed by weekly evaluations, magnetic resonance imaging (MRI), and at autopsy for tumorigenicity. At 90 days after intraosseous cell administration, the comparable expression of HLA-ABC class I antigens in selected organs was found in UCB control and HUDC therapy groups. MRI and autopsy confirmed safety by no signs of tumor growth. This study confirmed HUDC biodistribution to selected lymphoid organs following intraosseous administration, without immunosuppression. These data introduce HUDCs as a novel promising approach for immunomodulation in transplantation.

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.

Application of the direct in-scope suction technique in antegrade flexible ureteroscopic lithotripsy for the removal of a large ureteric calculus in a kidney transplant recipient: A case report

The occurrence of a large ureteric calculus in a transplanted kidney, originating from a donor, is a rare but significant complication. It poses risks such as urinary obstruction, septicemia, and potential loss of allograft function. In this case, we report our first use of the direct in-scope suction technique during antegrade flexible ureteroscopy lithotripsy. This method successfully removed a donor-derived ureteric calculus in a kidney transplant recipient. The procedure resulted in complete stone removal, and the patient experienced a favorable postoperative recovery without additional adverse events.

Dialyzing a Brain-Dead Individual for Organ Procurement

Many patients are unable to receive organ transplantation as there is an expanding gap between the number of patients waiting for an organ and the number who receive it. Organ procurement from the brain-dead can address this expanding gap, especially because one brain-dead patient can potentially donate multiple organs to several recipients. Here, we describe a rare case of a previously healthy 26-year-old male who was declared brain dead after a motor vehicle accident but underwent hemodialysis to treat his acute kidney injury and hyperkalemia before successfully donating his heart and left kidney.

Knowledge, Attitudes, and Practices Regarding Organ Donation Among Medical Students in India: A Mixed Methods Study

BACKGROUND

Deceased organ donation rates are extremely low in India. As future physicians, medical students can advocate organ donation in society. However, their knowledge, attitudes, and practices regarding organ donation remain understudied in India. Therefore, the present study aimed to assess the knowledge, attitudes, and practices related to deceased organ donation among undergraduate medical students in India using a mixed methods approach.

MATERIALS AND METHODS

This is a mixed-method study with a cross-sectional survey conducted among 400 randomly selected medical students at a medical college in India using a pretested questionnaire. Additionally, 20 in-depth interviews were conducted to gain qualitative insights.

RESULTS

Knowledge was high regarding organ donation (90%) but lower for brain death (27.5%). Most had positive attitudes, but only 11% were registered donors, and 10% had discussed organ donation with family. Multivariate regression revealed that having third- and fourth-year-old students, urban upbringing, good knowledge, and positive attitudes were associated with increased willingness to donate. Qualitative findings revealed gaps in brain death understanding, religious myths, lack of conviction, and family disapproval as barriers.

CONCLUSION

Despite good awareness, gaps in the comprehension of brain death persist among students. However, the registration and family discussion rates are very low. Targeted strategies such as integrating ethical issues into medical curricula, public awareness campaigns busting myths, simplifying donor registration, and promoting family conversations are strongly recommended. This can empower students to become physician advocates driving organ donation uptake in India.

Understanding Alcohol Relapse in Liver Transplant Patients With Alcohol-Related Liver Disease: A Comprehensive Review

Alcohol-related liver disease (ALD) presents a significant global health concern, with liver transplantation being a crucial intervention for patients in the advanced stages of the disease. However, the persistent risk of alcohol relapse in transplant recipients with ALD remains a formidable challenge. This comprehensive review explores the multifaceted nature of alcohol relapse, from its underlying factors to strategies for prevention. It highlights the importance of rigorous pre-transplant assessments, effective post-transplant interventions, and the role of multidisciplinary care teams in mitigating the risk of relapse. Furthermore, the review underscores the significance of adopting a holistic approach to ALD and transplantation, acknowledging the interconnectedness of medical, psychosocial, and psychological factors. With this holistic approach, we aim to enhance patient outcomes, reduce relapse rates, and ultimately improve the overall quality of life for individuals affected by ALD.

Donor Evaluation Protocol for Live and Deceased Donors

Donor evaluation is a critical step before proceeding with liver transplantation (LT) in both deceased donor LT (DDLT) and living donor LT (LDLT). A good, healthy graft is necessary for the success of the transplantation. Other issues in selecting a donor include the transmission of infections and malignancies from the donor. Because of the scarcity of cadaver organs, an increasing number of extended-criteria donors, or 'marginal donors', are being utilized. LDLT also has potential risks to the donor, and donor safety needs to be kept in mind before proceeding with LT. The current review highlights the factors to be considered during donor evaluation for living and deceased donors before LT.

Enhanced recellularization by using albumin coating with roller bottle cell culture

Introduction

The decellularization and recellularization is a promising approach for tissue engineering and regenerative medicine. However, the decellularization process depletes important components like glycosaminoglycans (GAGs), affecting cell attachment and causing immunogenicity. Studies have explored various surface modification strategies to enhance recellularization.

Methods

To optimize the decellularization method, we employed whole kidney perfusion and slice kidney immersion/agitation techniques. The decellularized extracellular matrix (dECM) was then analyzed using hematoxylin and eosin (H&E) staining, scanning electron microscope (SEM), and DNA quantification. To enhance cell proliferation efficiency, albumin coating and rotating culture were applied. Also, we evaluated in vitro blood clot formation on the albumin-coated dECM by immersing it in blood.

Results

After decellularization, the unique structures of the kidney were preserved whether cellular components were removed. Subsequently, we utilized albumin coating and rotating culture for recellularization, and observed that albumin-coated dECM not only promoted high cell proliferation rates but also prevented blood clot formation.

Conclusion

The albumin-coated dECM promoted cell proliferation and reduced blood clot formation in vitro. Also, dynamic culture condition using rotating culture allowed for improved cellular penetration into the dECM, leading to a conductive environment for enhanced tissue infiltration. This new approach suggests that the combined utilization of albumin coating and rotating culture conditions can improve the efficiency of recellularization.

Feasibility and outcomes of living-donor liver transplantation utilizing the right hemi-liver graft with portal vein anatomical variations

PURPOSE

Portal vein (PV) reconstruction is a key factor for successful living-donor liver transplantation (LDLT). Anatomical variations of right PV (RPV) are encountered among potential donors.

METHODS

To evaluate a single center experience of reconstruction techniques for the right hemi-liver grafts with PV variations during the period between May 2004 and 2022.

RESULTS

A total of 915 recipients underwent LDLT, among them 52 (5.8%) had RPV anatomical variations. Type II PV was found in 7 cases (13.5%), which were reconstructed by direct venoplasty. Type III PV was found in 27 cases (51.9%). They were reconstructed by direct venoplasty in 2 cases (3.8%), Y graft interposition in 2 cases (3.8%), and in situ double PV anastomoses in 23 cases (44.2%). Type IV PV was found in 18 cases (34.6%) and was reconstructed by Y graft interposition in 9 cases (17.3%), and in situ double PV anastomoses in 9 cases (17.3%). Early right posterior PV stenosis occurred in 2 recipients (3.8%). Early PV thrombosis occurred in 3 recipients (5.8%). The median follow-up duration was 54.5 months (4 - 185). The 1-, 3-, and 5-years survival rates were 91.9%, 86%, and 81.2%, respectively. Late PV stenosis occurred in 2 recipients (3.8%) and was managed conservatively.

CONCLUSION

Utilization of potential living donors with RPV anatomic variations may help to expand the donor pool. We found that direct venoplasty and in situ dual PV anastomoses techniques were safe, feasible, and associated with successful outcomes.

NO-IL-6/10-IL-1β axis: a new pathway in steatotic and non-steatotic liver grafts from brain-dead donor rats

INTRODUCTION

Brain death (BD) and steatosis are both risk factors for organ dysfunction or failure in liver transplantation (LT).

MATERIAL AND METHODS

Here, we examine the role of interleukin 6 (IL- 6) and IL-10 in LT of both non-steatotic and steatotic liver recovered from donors after brain death (DBDs), as well as the molecular signaling pathways underlying the effects of such cytokines.

RESULTS

BD reduced IL-6 levels only in nonsteatotic grafts, and diminished IL-10 levels only in steatotic ones. In both graft types, BD increased IL-1β, which was associated with hepatic inflammation and damage. IL-6 administration reduced IL-1β only in non-steatotic grafts and protected them against damage and inflammation. Concordantly, IL-1β inhibition via treatment with an IL-1 receptor antagonist caused the same benefits in non-steatotic grafts. Treatment with IL-10 decreased IL-1β only in steatotic grafts and reduced injury and inflammation specifically in this graft type. Blockading the IL-1β effects also reduced damage and inflammation in steatotic grafts. Also, blockade of IL-1β action diminished hepatic cAMP in both types of livers, and this was associated with a reduction in liver injury and inflammation, then pointing to IL-1β regulating cAMP generation under LT and BD conditions. Additionally, the involvement of nitric oxide (NO) in the effects of interleukins was evaluated. Pharmacological inhibition of NO in LT from DBDs prompted even more evident reductions of IL-6 or IL-10 in non-steatotic and steatotic grafts, respectively. This exacerbated the already high levels of IL-1β seen in LT from DBDs, causing worse damage and inflammation in both graft types. The administration of NO donors to non-steatotic grafts potentiated the beneficial effects of endogenous NO, since it increased IL-6 levels, and reduced IL-1β, inflammation, and damage. However, treatment with NO donors in steatotic grafts did not modify IL-10 or IL-1β levels, but induced more injurious effects tan the induction of BD alone, characterized by increased nitrotyrosine, lipid peroxidation, inflammation, and hepatic damage.

CONCLUSION

Our study thus highlights the specificity of new signaling pathways in LT from DBDs: NO-IL-6-IL-1β in non-steatotic livers and NO-IL-10-IL-1β in steatotic ones. This opens up new therapeutic targets that could be useful in clinical LT.

Undergraduate Education in Transplantation

INTRODUCTION

Training in the transplants of organs, tissues, and cells as a therapeutic modality of multiple pathologies is essential in undergraduate education. The medical aspects typical of the theme are associated with ethical, legal, religious, and philosophical concerns, giving a holistic view of the process. We present a teaching model of the donation-transplant process with 15 years of experience.

METHODS

The subject of Organ, Tissue, and Cell Transplants began its activities in 2008. It is an elective, annual subject included in the last year of the medical career. Since its inception, it has established a continuous teaching methodology with a global approach to the donation and transplantation process.

RESULTS

During the last 15 years and until the moment of the presentation, 1057 students have registered for the subject, 80.6% (852) completed the requirements of approval of the course, 79.9% of the students presented for the final evaluation (681), and 96.4% (654) of the students passed the final assessment. The average final grade calculated was equal to 6.53 ± 2.9 points out of 10; 205 students (19.4%) still need to comply with the final evaluative instance.

CONCLUSION

The available literature has different training modalities, but none resembles the model presented. It is concluded that, during these 15 years, the pedagogic expectations in the training of human resources have been exceeded.

The Effect of Calcineurin Inhibitors on MMPs Activity in Heart and Their Side Effects-A Review of Literature

This review focuses on the role of metalloproteinases in the pathogenesis of myocardial injury in various disease entities. It reveals how the expression and serum levels of metalloproteinases and their inhibitors change in many disease states. At the same time, the study offers a review of the impact of immunosuppressive treatment on this relationship. Modern immunosuppressive treatment is based mainly on the use of calcineurin inhibitors, including cyclosporine A and tacrolimus. The use of these drugs may carry a number of side effects, specifically to the cardiovascular system. The scale and degree of long-term influence on the organism remains unclear, but a significant risk of complications for transplant recipients who take immunosuppressive drugs as part of their daily treatment is to be expected. Therefore, the knowledge on this subject should be expanded and the negative effects of post-transplant therapy minimized. Immunosuppressive therapy plays an important role in the expression and activation of tissue metalloproteinases and their specific inhibitors, which leads to many tissue changes. The presented study is a collection of research results on the effects of calcineurin inhibitors on the heart, with particular emphasis placed on the participation of MMP-2 and MMP-9. It is also an analysis of the effects of specific heart diseases on myocardial remodeling through inductive or inhibitory effects on matrix metalloproteinases and their inhibitors.

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.

Silk Fibroin and Sericin Differentially Potentiate the Paracrine and Regenerative Functions of Stem Cells Through Multiomics Analysis

Silk fibroin (SF) and sericin (SS), the two major proteins of silk, are attractive biomaterials with great potential in tissue engineering and regenerative medicine. However, their biochemical interactions with stem cells remain unclear. In this study, multiomics are employed to obtain a global view of the cellular processes and pathways of mesenchymal stem cells (MSCs) triggered by SF and SS to discern cell-biomaterial interactions at an in-depth, high-throughput molecular level. Integrated RNA sequencing and proteomic analysis confirm that SF and SS initiate widespread but distinct cellular responses and potentiate the paracrine functions of MSCs that regulate extracellular matrix deposition, angiogenesis, and immunomodulation through differentially activating the integrin/PI3K/Akt and glycolysis signaling pathways. These paracrine signals of MSCs stimulated by SF and SS effectively improve skin regeneration by regulating the behavior of multiple resident cells (fibroblasts, endothelial cells, and macrophages) in the skin wound microenvironment. Compared to SS, SF exhibits better immunomodulatory effects in vitro and in vivo, indicating its greater potential as a carrier material of MSCs for skin regeneration. This study provides comprehensive and reliable insights into the cellular interactions with SF and SS, enabling the future development of silk-based therapeutics for tissue engineering and stem cell therapy.

Organ Transplants From Deceased Donors With Primary Brain Tumors and Risk of Cancer Transmission

IMPORTANCE

Cancer transmission is a known risk for recipients of organ transplants. Many people wait a long time for a suitable transplant; some never receive one. Although patients with brain tumors may donate their organs, opinions vary on the risks involved.

OBJECTIVE

To determine the risk of cancer transmission associated with organ transplants from deceased donors with primary brain tumors. Key secondary objectives were to investigate the association that donor brain tumors have with organ usage and posttransplant survival.

DESIGN, SETTING, AND PARTICIPANTS

This was a cohort study in England and Scotland, conducted from January 1, 2000, to December 31, 2016, with follow-up to December 31, 2020. This study used linked data on deceased donors and solid organ transplant recipients with valid national patient identifier numbers from the UK Transplant Registry, the National Cancer Registration and Analysis Service (England), and the Scottish Cancer Registry. For secondary analyses, comparators were matched on factors that may influence the likelihood of organ usage or transplant failure. Statistical analysis of study data took place from October 1, 2021, to May 31, 2022.

EXPOSURES

A history of primary brain tumor in the organ donor, identified from all 3 data sources using disease codes.

MAIN OUTCOMES AND MEASURES

Transmission of brain tumor from the organ donor into the transplant recipient. Secondary outcomes were organ utilization (ie, transplant of an offered organ) and survival of kidney, liver, heart, and lung transplants and their recipients. Key covariates in donors with brain tumors were tumor grade and treatment history.

RESULTS

This study included a total of 282 donors (median [IQR] age, 42 [33-54] years; 154 females [55%]) with primary brain tumors and 887 transplants from them, 778 (88%) of which were analyzed for the primary outcome. There were 262 transplants from donors with high-grade tumors and 494 from donors with prior neurosurgical intervention or radiotherapy. Median (IQR) recipient age was 48 (35-58) years, and 476 (61%) were male. Among 83 posttransplant malignancies (excluding NMSC) that occurred over a median (IQR) of 6 (3-9) years in 79 recipients of transplants from donors with brain tumors, none were of a histological type matching the donor brain tumor. Transplant survival was equivalent to that of matched controls. Kidney, liver, and lung utilization were lower in donors with high-grade brain tumors compared with matched controls.

CONCLUSIONS AND RELEVANCE

Results of this cohort study suggest that the risk of cancer transmission in transplants from deceased donors with primary brain tumors was lower than previously thought, even in the context of donors that are considered as higher risk. Long-term transplant outcomes are favorable. These results suggest that it may be possible to safely expand organ usage from this donor group.

Realizations of vascularized tissues: From in vitro platforms to in vivo grafts

Vascularization is essential for realizing thick and functional tissue constructs that can be utilized for in vitro study platforms and in vivo grafts. The vasculature enables the transport of nutrients, oxygen, and wastes and is also indispensable to organ functional units such as the nephron filtration unit, the blood-air barrier, and the blood-brain barrier. This review aims to discuss the latest progress of organ-like vascularized constructs with specific functionalities and realizations even though they are not yet ready to be used as organ substitutes. First, the human vascular system is briefly introduced and related design considerations for engineering vascularized tissues are discussed. Second, up-to-date creation technologies for vascularized tissues are summarized and classified into the engineering and cellular self-assembly approaches. Third, recent applications ranging from in vitro tissue models, including generic vessel models, tumor models, and different human organ models such as heart, kidneys, liver, lungs, and brain, to prevascularized in vivo grafts for implantation and anastomosis are discussed in detail. The specific design considerations for the aforementioned applications are summarized and future perspectives regarding future clinical applications and commercialization are provided.

Ethical considerations for theatre teams in organ donation after circulatory determination of death

Transplant surgery is an area that gives rise to a number of ethical considerations. As medicine continues to expand the boundaries of what is technically possible, we must consider the ethical implications of our interventions, not solely on patients and society, but also on those asked to provide that care. Here, we consider physician participation in procedures required to provide patient care in the context of the ethical convictions held by the physician, with an emphasis on organ donation after circulatory determination of death. Strategies that can be used to mitigate any potential negative impact on the psychological well-being of members of the patient care team are considered.

Engineered tissue vascularization and engraftment depends on host model

Developing vascular networks that integrate with the host circulation and support cells engrafted within engineered tissues remains a key challenge in tissue engineering. Most previous work in this field has focused on developing new methods to build human vascular networks within engineered tissues prior to their implant in vivo, with substantively less attention paid to the role of the host in tissue vascularization and engraftment. Here, we assessed the role that different host animal models and anatomic implant locations play in vascularization and cardiomyocyte survival within engineered tissues. We found major differences in the formation of graft-derived blood vessels and survival of cardiomyocytes after implantation of identical tissues in immunodeficient athymic nude mice versus rats. Athymic mice supported robust guided vascularization of human microvessels carrying host blood but relatively sparse cardiac grafts within engineered tissues, regardless of implant site. Conversely, athymic rats produced substantive inflammatory changes that degraded grafts (abdomen) or disrupted vascular patterning (heart). Despite disrupted vascular patterning, athymic rats supported > 3-fold larger human cardiomyocyte grafts compared to athymic mice. This work demonstrates the critical importance of the host for vascularization and engraftment of engineered tissues, which has broad translational implications across regenerative medicine.

3D Bioprinting tissue analogs: Current development and translational implications

Three-dimensional (3D) bioprinting is a promising and rapidly evolving technology in the field of additive manufacturing. It enables the fabrication of living cellular constructs with complex architectures that are suitable for various biomedical applications, such as tissue engineering, disease modeling, drug screening, and precision regenerative medicine. The ultimate goal of bioprinting is to produce stable, anatomically-shaped, human-scale functional organs or tissue substitutes that can be implanted. Although various bioprinting techniques have emerged to develop customized tissue-engineering substitutes over the past decade, several challenges remain in fabricating volumetric tissue constructs with complex shapes and sizes and translating the printed products into clinical practice. Thus, it is crucial to develop a successful strategy for translating research outputs into clinical practice to address the current organ and tissue crises and improve patients' quality of life. This review article discusses the challenges of the existing bioprinting processes in preparing clinically relevant tissue substitutes. It further reviews various strategies and technical feasibility to overcome the challenges that limit the fabrication of volumetric biological constructs and their translational implications. Additionally, the article highlights exciting technological advances in the 3D bioprinting of anatomically shaped tissue substitutes and suggests future research and development directions. This review aims to provide readers with insight into the state-of-the-art 3D bioprinting techniques as powerful tools in engineering functional tissues and organs.

In defense of xenotransplantation research: Because of, not in spite of, animal welfare concerns

It is envisioned that one day xenotransplantation will bring about a future where transplantable organs can be safely and efficiently grown in transgenic pigs to help meet the global organ shortage. While recent advances have brought this future closer, worries remain about whether it will be beneficial overall. The unique challenges and risks posed to humans that arise from transplanting across the species barrier, in addition to the costs borne by non-human animals, has led some to question the value of xenotransplantation altogether. In response, we defend the value of xenotransplantation research, because it can satisfy stringent welfare conditions on the permissibility of animal research and use. Along the way, we respond to the alleged concerns, and conclude that they do not currently warrant a cessation or a curtailing of xenotransplantation research.

Assessment of Community Knowledge of and Attitude Toward Organ Donation in Saudi Arabia

BACKGROUND

The demand for organ donation has increased because of the sharp rise in the number of transplant candidates worldwide. The main influences on the organ donation rate in Saudi Arabia were religious considerations and a lack of knowledge. The aim of this study was to explore community knowledge of and attitude toward organ donation in Saudi Arabia.

METHODS

An online cross-sectional survey study was conducted to assess community knowledge of and attitude toward organ donation in Saudi Arabia in January 2022. The study population consisted of everyone who is currently residing in Saudi Arabia and is aged ≥18 years. The participants were questioned regarding the types of organs that might be donated, the potential health risks associated with organ donation, and the Saudi Arabian system for organ donation. Logistic regression was used to identify predictors of better knowledge of and attitude toward organ donation.

RESULTS

The study involved 1208 participants, of which 63% reported that they would be willing to donate their organs for a family member. The most reported organs for which the participants reported they are willing to donate were the kidneys (48%), liver (25%), and heart (21%). Most reported that they would donate their organs to save someone's life (93%). The study participants showed mild to moderate level of knowledge about organ donation with a mean score of 5.4 (standard deviation [SD] 1.6), which is equal to 68% of the maximum obtainable score (which is 8). The study participants showed a mild positive attitude toward organ donation with a mean score of 3.3 (SD 1.3), which is equal to 47% of the maximum obtainable score (which is 7). Younger participants (aged 19-30 years) and those who work in the health care sector were more likely than others to be knowledgeable about organ donation (P ≤ .01). At the same time, participants aged 31 to 40 years were more likely than others to have positive attitudes toward organ donation (P ≤ .01).

CONCLUSIONS

The present study participants showed mild to moderate level of knowledge of and mild positive attitude toward organs donation. Awareness campaigns should be directed toward the elderly population to enhance their awareness and attitude toward this important lifesaving practice.

First Successful Human Coronary Artery Bypass Surgery Postoperative Heart Transplant: A Case Report

Heart transplant is now the treatment of choice for patients with advanced heart failure who are refractory to medical treatment. With a small number of candidates who meet the traditional criteria of a heart donor, we aimed to alleviate this shortage. In this article, we report a 43-year-old woman with a highly urgent heart requirement, according to acute decompensated heart failure, who received a heart with coronary artery grafts from a 50-year-old woman with the diagnosis of 3-vessel disease. Our review of her 1-year follow-up demonstrated the absence of any cardiac or other problems and survival of the patient. There have been no reports in the relevant literature of transplanting marginal hearts from donors who have previously undergone coronary artery bypass graft before transplant. According to our findings, transplant of a marginal heart with coronary artery grafts can be successful; additional studies with larger samples are warranted to further investigate the results of transplanting marginal hearts from donors who have previously undergone coronary artery bypass graft procedures.

Novel gold-platinum nanoparticles serve as broad-spectrum antioxidants for attenuating ischemia reperfusion injury of the kidney

Kidney ischemia reperfusion injury (IRI) is a common and inevitable pathological condition in routine urological practices, especially during transplantation. Severe kidney IRI may even induce systemic damage to peripheral organs, and lead to multisystem organ failure. However, no standard clinical treatment option is currently available. It has been reported that kidney IRI is predominantly associated with abnormally increased endogenous reactive oxygen species (ROS). Scavenging excessive ROS may reduce the damage caused by oxidative stress and subsequently alleviate kidney IRI. Here, we reported a simple and efficient one-step synthesis of gold-platinum nanoparticles (AuPt NPs) with a gold core having a loose and branched outer platinum shell with superior ROS scavenging capacity to possibly treat kidney IRI. These AuPt NPs exhibited multiple enzyme-like anti-oxidative properties simultaneously possessing catalase- and peroxidase-like activity. These particles showed excellent cell protective capability, and alleviated kidney IRI both in vitro and in vivo without obvious toxicity, by suppressing cell apoptosis, inflammatory cytokine release, and inflammasome formation. Meanwhile, AuPt NPs also had an effect on inhibiting the transition to chronic kidney disease by reducing kidney fibrosis in the long term. Thus, AuPt NPs might be a good therapeutic agent for kidney IRI management and may be helpful for the development of clinical treatments for kidney IRI.

Advance of genetically modified pigs in xeno-transplantation

As the standard of living improves, chronic diseases and end-stage organ failure have been a regular occurrence in human beings. Organ transplantation has become one of the hopes in the fight against chronic diseases and end-stage organ failure. However, organs available for transplantation are far from sufficient to meet the demand, leading to a major organ shortage crisis. To solve this problem, researchers have turned to pigs as their target since pigs have many advantages as xenograft donors. Pigs are considered the ideal organ donor for human xenotransplantation, but direct transplantation of porcine organs to humans faces many obstacles, such as hyperacute rejection, acute humoral xenograft rejection, coagulation dysregulation, inflammatory response, coagulation dysregulation, and endogenous porcine retroviral infection. Many transgenic strategies have been developed to overcome these obstacles. This review provides an overview of current advances in genetically modified pigs for xenotransplantation. Future genetic engineering-based delivery of safe and effective organs and tissues for xenotransplantation remains our goal.

Construction of an Index System for Assessing Competences of Transplant Coordinators in China: A Delphi Survey

BACKGROUND

Transplant coordinators (TCs) play a pivotal role in the entire donation process. Their professional competences have a direct impact on donation rates. However, few specific indicators are available for assessing TCs' professional competence. Therefore, it is imperative to develop an assessment index system to measure their competence. Our objective was to construct an index system for assessing TCs' professional competences.

METHODS

Based on a literature review and semistructured interviews, a focus group and 12 TCs were enrolled to design the questionnaires. Then, a modified Delphi method was used. Two rounds of questionnaires were distributed to 21 experts from 7 provinces across multiple research areas between October 2020 and March 2021. The data were sorted and analyzed by a focus group.

RESULTS

A combined assessment index system, namely, APT, including 3 constructs, the admittance assessment model (henceforth A), practical operation assessment model (P), and thousand-point performance assessment model (T), was constructed. This APT index system consisted of 3 first-level items, 8 second-level items, and 34 third-level items.

CONCLUSIONS

The APT assessment system has been unanimously recognized by experts. This index system, as a precursor form, will further lay the foundation for formation of an assessment instrument and provide references for other countries.

Electrospun Nanofiber Composites for Drug Delivery: A Review on Current Progresses

A medication's approximate release profile should be sustained in order to generate the desired therapeutic effect. The drug's release site, duration, and rate must all be adjusted to the drug's therapeutic aim. However, when designing drug delivery systems, this may be a considerable hurdle. Electrospinning is a promising method of creating a nanofibrous membrane since it enables drugs to be placed in the nanofiber composite and released over time. Nanofiber composites designed through electrospinning for drug release purposes are commonly constructed of simple structures. This nanofiber composite produces matrices with nanoscale fiber structure, large surface area to volume ratio, and a high porosity with small pore size. The nanofiber composite's large surface area to volume ratio can aid with cell binding and multiplication, drug loading, and mass transfer processes. The nanofiber composite acts as a container for drugs that can be customized to a wide range of drug release kinetics. Drugs may be electrospun after being dissolved or dispersed in the polymer solution, or they can be physically or chemically bound to the nanofiber surface. The composition and internal structure of the nanofibers are crucial for medicine release patterns.

Passive and Active Microrheology for Biomedical Systems

Microrheology encompasses a range of methods to measure the mechanical properties of soft materials. By characterizing the motion of embedded microscopic particles, microrheology extends the probing length scale and frequency range of conventional bulk rheology. Microrheology can be characterized into either passive or active methods based on the driving force exerted on probe particles. Tracer particles are driven by thermal energy in passive methods, applying minimal deformation to the assessed medium. In active techniques, particles are manipulated by an external force, most commonly produced through optical and magnetic fields. Small-scale rheology holds significant advantages over conventional bulk rheology, such as eliminating the need for large sample sizes, the ability to probe fragile materials non-destructively, and a wider probing frequency range. More importantly, some microrheological techniques can obtain spatiotemporal information of local microenvironments and accurately describe the heterogeneity of structurally complex fluids. Recently, there has been significant growth in using these minimally invasive techniques to investigate a wide range of biomedical systems both in vitro and in vivo. Here, we review the latest applications and advancements of microrheology in mammalian cells, tissues, and biofluids and discuss the current challenges and potential future advances on the horizon.