New and old technologies for organ replacement

Organ transplantation in Africa: Confronting socioeconomic, cultural, and infrastructural hurdles

BACKGROUND

Organ transplantation is a critical procedure offering life-saving treatment for patients with end-stage organ failure. In Africa, however, the accessibility and development of organ transplantation are severely hampered by numerous barriers. Socioeconomic disparities, inadequate healthcare infrastructure, legal and ethical gaps, cultural resistance, and the dual burden of infectious and non-communicable diseases are among the significant challenges faced. This review aims to comprehensively explore these barriers and propose actionable strategies to address them.

METHOD

A narrative review was conducted by searching electronic databases, including PubMed, Google Scholar, Scopus, and JSTOR. The review prioritized studies addressing the challenges of organ transplantation in Africa, focusing on socioeconomic factors, healthcare infrastructure, cultural beliefs, legal frameworks, and the impact of infectious and non-communicable diseases. Studies offering solutions tailored to the African context were also included.

RESULTS

The review identified several key obstacles, including high costs of transplantation, a limited number of transplant centers, and a critical shortage of skilled healthcare professionals. Cultural beliefs and widespread misconceptions impede organ donation acceptance. Additionally, infectious and non-communicable diseases complicate the transplantation process and outcomes. Weak legal frameworks exacerbate the risks of organ trafficking and unethical practices, while low public awareness further undermines efforts to enhance organ donation rates.

CONCLUSION

Addressing these multifaceted challenges necessitates a comprehensive approach. Strengthening healthcare infrastructure, enhancing capacity-building programs, developing robust legal and ethical frameworks, and implementing targeted public education campaigns are critical for improving organ transplantation in Africa.

Tele-ICU enabled management of an organ donor in an under-resourced setting

A man in his 30s was involved in a road traffic crash in a small town in India, not equipped to deal with cases of brainstem death. He was declared brain-dead after a few hours. The patient's information was forwarded to organ specialists across the country, with the goal of preserving the patient's organs for donation via a tele-ICU model. The team comprising bedside doctors and remote intensivists communicating via an indigenously developed tele-ICU platform managed the patient for 24 hours, following treatment protocols and providing critical care to ensure that the patient's vital organs were optimally perfused. The following morning, specialist teams from a nearby city arrived at the local hospital to retrieve the patient's organs. This fast-tracked organ retrieval and transplant process were made possible through advances in technology and the involvement of specialists from other parts of the country through this tele-ICU model.

External Vs Internal e-Referrals: Results from a Nationwide Epidemiological Study Utilizing Secondary Collected Data

Background

E-referral systems, streamlining patient access to specialists, have gained global recognition yet lacked a comparative study between internal and external referrals in Saudi Arabia (KSA).

Methods

This retrospective study utilized secondary data from the Saudi Medical Appointments and Referrals Centre system. The data covers 2020 and 2021, including socio-demographic data, referral characteristics, and specialties. Logistic regression analysis was used to assess factors associated with external referrals.

Results

Out of 645,425 e-referrals from more than 300 hospitals, 19.87% were external. The northern region led with 48.65%. Males were 55%, and those aged 25-64 were 56.68% of referrals. Outpatient clinic referrals comprised 47%, while 61% of referrals were due to a lack of specialty services. Several significant determinants are associated with higher rates of external referral with (p-value <0.001) and a 95% Confidence interval. Younger individuals under 25 exhibit higher referral rates than those aged 25-64. Geographically, compared to the central region, in descending order, there were increasing trends of external referral in the northern, western, and southern regions, respectively (OR = 19.26, OR = 4.48, OR 3.63). External referrals for outpatient departments (OPD) and dialysis services were higher than for routine admissions (OR = 1.38, OR = 1.26). The rate of external referrals due to the lack of available equipment was more predominant than other causes. Furthermore, in descending order, external referrals for organ transplantation and oncology are more frequent than for medical specialties, respectively (OR = 9.39, OR = 4.50).

Conclusion

The study reveals trends in e-referrals within the KSA, noting regional differences, demographic factors, and types of specialties regarding external referrals, benefiting the New Model of Care for the 2030 Vision. Findings suggest expanding virtual consultations to reduce external referrals. Strengthening primary care and preventive medicine could also decrease future referrals. Future studies should assess resource distribution, including infrastructure and workforce, to further inform healthcare strategy.

In Situ Characterization of Polycaprolactone Fiber Response to Quasi-Static Tensile Loading in Scanning Electron Microscopy

Microstructural responses to the mechanical load of polymers used in tissue engineering is notably important for qualification at in vivo testing, although insufficiently studied, especially regarding promising polycaprolactone (PCL). For further investigations, electrospun PCL scaffolds with different degrees of fiber alignment were produced, using two discrete relative drum collector velocities. Development and preparation of an adjusted sample geometry enabled in situ tensile testing in scanning electron microscopy. By analyzing the microstructure and the use of selected tracking techniques, it was possible to visualize and quantify fiber/fiber area displacements as well as local fractures of single PCL fibers, considering quasi-static tensile load and fiber alignment. The possibility of displacement determination using in situ scanning electron microscopy techniques for testing fibrous PCL scaffolds was introduced and quantified.

Healing effects of a protein scaffold loaded with adipose-derived mesenchymal stem cells on radiation-induced vaginal injury in rats

Objectives

Cervical cancer, the most common female cancer after breast cancer, is typically treated using radiotherapy. However, pelvic radiotherapy can cause irreversible damage to the vagina, seriously affecting patients’ quality of life. In this study, protein scaffolds loaded with rat adipose-derived mesenchymal stem cells (ADSCs) were implanted into irradiated tissue to assess their healing potential.

Methods

We established a rat model of radiation-induced vaginal injury. Complexes (consisting of protein scaffolds loaded with ADSCs) were implanted into injury sites. Histological analysis were used to assess regeneration of the vaginal epithelium. RNA sequencing was used to study the therapeutic mechanism of the complexes.

Results

The complexes promoted vaginal epithelial cell regeneration, vaginal tissue repair and improved vaginal stenosis and contracture. Compared with rats transplanted with ADSCs, rats transplanted with complexes achieved better therapeutic effects.

Conclusions

Protein scaffold-ADSC complexes had a beneficial therapeutic effect on radiation-induced vaginal injury in rats and may serve as the basis of a novel therapeutic approach for radiation dermatitis.

Mesenchymal Stem Cell-Derived Extracellular Vesicles: Regenerative Potential and Challenges

Evidence suggests that stem cells exert regenerative potential via the release of extracellular vesicles. Mesenchymal stem cell extracellular vesicles (MSCEVs) offer therapeutic benefits for various pathophysiological ailments by restoring tissues. Facts suggest that MSCEV action can be potentiated by modifying the mesenchymal stem cells culturing methodology and bioengineering EVs. Limited clinical trials of MSCEVs have questioned their superiority, culturing quality, production scale-up and isolation, and administration format. Translation of preclinically successful MSCEVs into a clinical platform requires paying attention to several critical matters, such as the production technique, quantification/characterization, pharmacokinetics/targeting/transfer to the target site, and the safety profile. Keeping these issues as a priority, the present review was designed to highlight the challenges in translating preclinical MSCEV research into clinical platforms and provide evidence for the regenerative potential of MSCEVs in various conditions of the liver, kidney, heart, nervous system, bone, muscle, cartilage, and other organs/tissues.

Supercritical carbon dioxide decellularization of plant material to generate 3D biocompatible scaffolds

The use of plant-based biomaterials for tissue engineering has recently generated interest as plant decellularization produces biocompatible scaffolds which can be repopulated with human cells. The predominant approach for vegetal decellularization remains serial chemical processing. However, this technique is time-consuming and requires harsh compounds which damage the resulting scaffolds. The current study presents an alternative solution using supercritical carbon dioxide (scCO2). Protocols testing various solvents were assessed and results found that scCO2 in combination with 2% peracetic acid decellularized plant material in less than 4 h, while preserving plant microarchitecture and branching vascular network. The biophysical and biochemical cues of the scCO2 decellularized spinach leaf scaffolds were then compared to chemically generated scaffolds. Data showed that the scaffolds had a similar Young's modulus, suggesting identical stiffness, and revealed that they contained the same elements, yet displayed disparate biochemical signatures as assessed by Fourier-transform infrared spectroscopy (FTIR). Finally, human fibroblast cells seeded on the spinach leaf surface were attached and alive after 14 days, demonstrating the biocompatibility of the scCO2 decellularized scaffolds. Thus, scCO2 was found to be an efficient method for plant material decellularization, scaffold structure preservation and recellularization with human cells, while performed in less time (36 h) than the standard chemical approach (170 h).

Mesenchymal Stem Cell Derived Extracellular Vesicles for Tissue Engineering and Regenerative Medicine Applications

Mesenchymal stem cells (MSCs) are being extensively investigated for their potential in tissue engineering and regenerative medicine. However, recent evidence suggests that the beneficial effects of MSCs may be manifest by their released extracellular vesicles (EVs); typically not requiring the administration of MSCs. This evidence, predominantly from pre-clinical in vitro and in vivo studies, suggests that MSC-EVs may exhibit substantial therapeutic properties in many pathophysiological conditions, potentially restoring an extensive range of damaged or diseased tissues and organs. These benefits of MSC EVs are apparently found, regardless of the anatomical or body fluid origin of the MSCs (and include e.g., bone marrow, adipose tissue, umbilical cord, urine, etc). Furthermore, early indications suggest that the favourable effects of MSC-EVs could be further enhanced by modifying the way in which the donor MSCs are cultured (for example, in hypoxic compared to normoxic conditions, in 3D compared to 2D culture formats) and/or if the EVs are subsequently bio-engineered (for example, loaded with specific cargo). So far, few human clinical trials of MSC-EVs have been conducted and questions remain unanswered on whether the heterogeneous population of EVs is beneficial or some specific sub-populations, how best we can culture and scale-up MSC-EV production and isolation for clinical utility, and in what format they should be administered. However, as reviewed here, there is now substantial evidence supporting the use of MSC-EVs in tissue engineering and regenerative medicine and further research to establish how best to exploit this approach for societal and economic benefit is warranted.

Xenotransplantation: Progress Along Paths Uncertain from Models to Application

For more than a century, transplantation of tissues and organs from animals into man, xenotransplantation, has been viewed as a potential way to treat disease. Ironically, interest in xenotransplantation was fueled especially by successful application of allotransplantation, that is, transplantation of human tissue and organs, as a treatment for a variety of diseases, especially organ failure because scarcity of human tissues limited allotransplantation to a fraction of those who could benefit. In principle, use of animals such as pigs as a source of transplants would allow transplantation to exert a vastly greater impact than allotransplantation on medicine and public health. However, biological barriers to xenotransplantation, including immunity of the recipient, incompatibility of biological systems, and transmission of novel infectious agents, are believed to exceed the barriers to allotransplantation and presently to hinder clinical applications. One way potentially to address the barriers to xenotransplantation is by genetic engineering animal sources. The last 2 decades have brought progressive advances in approaches that can be applied to genetic modification of large animals. Application of these approaches to genetic engineering of pigs has contributed to dramatic improvement in the outcome of experimental xenografts in nonhuman primates and have encouraged the development of a new type of xenograft, a reverse xenograft, in which human stem cells are introduced into pigs under conditions that support differentiation and expansion into functional tissues and potentially organs. These advances make it appropriate to consider the potential limitation of genetic engineering and of current models for advancing the clinical applications of xenotransplantation and reverse xenotransplantation.

Ethics and Well-Being: Ages 45-64: 70 is the New 50

The age range 45-64 covers a life-stage when ideally, health status is reasonably manageable. However, this life-stage also poses health risks, which may lead to diseases, illnesses, dysfunctions, disabilities and early death. In fact, over the last three years, life expectancy among non-Hispanic white men has decreased. The opportunity to synergize ethics, health and well-being at the individual and group/community level is also highlighted. Various sphere of ethics and how they impact on individual, group/community well-being strategically, infuses ethics into health and health care conversations. Difficult term to operationalize like well-being, health, ethics and healing are deliberated. The phrase "70 is the new 50" reflects an importance opportunity to discuss what it means to be middle age and be healthy. There are health threats created by social and environment injustices and food deserts which are important considerations influencing health. The concept of Optimal Health, as a group strategy to advance health, particularly for people of African descent, details five group domains: optimal physical, emotional, social-economic, intellectual, and spiritual health. Optimal Health translated into individual behavior also has five health promotion principles that are detailed in the article. Synergizing Optimal Health, at the group/community level, with the five Health Promotion Principles, at the individual level, is the ideal journey toward individual and group/community well-being. Persons ages 45-64 are poised to combine the wisdom gained from their lived experiences, with the knowledge acquired from their positive or negative interfaces with the health delivery system, are generously available to achieve Optimal Health. The article concludes by discussing the Ancient African Imhotep, True Father of Medicine, 2980 B.C.E.

Toward a solution for cardiac failure in the newborn

The newborn infant with severe cardiac failure owed to congenital structural heart disease or cardiomyopathy poses a daunting therapeutic challenge. The ideal solution for both might be cardiac transplantation if availability of hearts was not limiting and if tolerance could be induced, obviating toxicity of immunosuppressive therapy. If one could safely and effectively exploit neonatal tolerance for successful xenotransplantation of the heart, the challenge of severe cardiac failure in the newborn infant might be met. We discuss the need, the potential for applying neonatal tolerance in the setting of xenotransplantation and the possibility that other approaches to this problem might emerge.

Opportunity cost in the economic evaluation of da Vinci robotic assisted surgery

OBJECTIVE

This study aims to demonstrate the importance of the opportunity cost in using da Vinci robotic surgery, assisted by a comprehensive review of the literature to determine the differences in the total cost of surgery and operative time in traditional laparoscopic surgery and da Vinci robotic surgery.

METHODOLOGY

We identified the studies comparing the use of traditional laparoscopic surgery with robotics during the period 2002-2012 in the electronic economic evaluation databases, and another electronic search was performed for publications by Spanish hospitals in the same period to calculate the opportunity cost. A meta-analysis of response variables considering the total cost of the intervention and surgical time was completed using the items selected in the first revision, and their differences were analyzed. We then calculated the opportunity cost represented by these time differences using the data obtained from the studies in the second review of the literature.

RESULTS

Nine items were selected in the first review and three in the second. Traditional laparoscopic surgery has a lower cost than the da Vinci (p < 0.00001). Robotic surgery takes longer (8.0-65.5 min) than traditional surgery (p < 0.00001), and this difference represents an average opportunity cost for robot use of € 489.98, with a unit cost factor/time which varies according to the pathology dealt with, from € 8.2 to 18.7/min.

CONCLUSIONS

The opportunity cost is a quantity that must be included in the total cost of using a surgical technology within an economic cost analysis in the context of an economic evaluation.

Silencing the porcine iGb3s gene does not affect Galα3Gal levels or measures of anticipated pig-to-human and pig-to-primate acute rejection

BACKGROUND

The Galα(1,3)Gal epitope (α-GAL), created by α-1,3-glycosyltransferase-1 (GGTA1), is a major xenoantigen causing hyperacute rejection in pig-to-primate and pig-to-human xenotransplantation. In response, GGTA1 gene-deleted pigs have been generated. However, it is unclear whether there is a residual small amount of α-Gal epitope expressed in GGTA1(-/-) pigs. Isoglobotrihexosylceramide synthase (iGb3s), another member of the glycosyltransferase family, catalyzes the synthesis of isoglobo-series glycosphingolipids with an α-GAL-terminal disaccharide (iGb3), creating the possibility that iGb3s may be a source of α-GAL epitopes in GGTA1(-/-) animals. The objective of this study was to examine the impact of silencing the iGb3s gene (A3GalT2) on pig-to-primate and pig-to-human immune cross-reactivity by creating and comparing GGTA1(-/-) pigs to GGTA1(-/-) - and A3GalT2(-/-) -double-knockout pigs.

METHODS

We used the CRISPR/Cas 9 system to target the GGTA1 and A3GalT2 genes in pigs. Both GGTA1 and A3GalT2 genes are functionally inactive in humans and baboons. CRISPR-treated cells used directly for somatic cell nuclear transfer produced single- and double-gene-knockout piglets in a single pregnancy. Once grown to maturity, the glycosphingolipid profile (including iGb3) was assayed in renal tissue by normal-phase liquid chromatography. In addition, peripheral blood mononuclear cells (PBMCs) were subjected to (i) comparative cross-match cytotoxicity analysis against human and baboon serum and (ii) IB4 staining for α-GAL/iGb3.

RESULTS

Silencing of the iGb3s gene significantly modulated the renal glycosphingolipid profile and iGb3 was not detected. Moreover, the human and baboon serum PBMC cytotoxicity and α-GAL/iGb3 staining were unchanged by iGb3s silencing.

CONCLUSIONS

Our data suggest that iGb3s is not a contributor to antibody-mediated rejection in pig-to-primate or pig-to-human xenotransplantation. Although iGb3s gene silencing significantly changed the renal glycosphingolipid profile, the effect on Galα3Gal levels, antibody binding, and cytotoxic profiles of baboon and human sera on porcine PBMCs was neutral.

Regeneration of uterine horns in rats using collagen scaffolds loaded with human embryonic stem cell-derived endometrium-like cells

A variety of diseases may lead to hysterectomies or uterine injuries, which may form a scar and lead to infertility. Due to the limitation of native materials, there are a few effective methods to treat such damages. Tissue engineering combines cell and molecular biology with materials and mechanical engineering to replace or repair damaged organs and tissues. The use of human embryonic stem cells (hESCs) as a donor cell source for the replacement therapy will require the development of simple and reliable cell differentiation protocols. This study aimed at efficiently generating endometrium-like cells from the hESCs and at using these cells with collagen scaffold to repair uterine damage. The hESCs were induced by co-culturing with endometrial stromal cells, and simultaneously added cytokines: epidermal growth factor (EGF), platelet-derived growth factor-b (PDGF-b), and E2. Expression of cell specific markers was analyzed by immunofluorescence and reverse trascription-polymerase chain reaction to monitor the progression toward an endometrium-like cell fate. After differentiation, the majority of cells (>80%) were positive for cytokeratin-7, and the expression of key transcription factors related to endometrial development, such as Wnt4, Wnt7a, Wnt5a, Hoxa11, and factors associated with endometrial epithelial cell function: Hoxa10, Intergrinβ3, LIF, ER, and PR were also detected. Then, we established the uterine full-thickness-injury rat models to test cell function in vivo. hESC-derived cells were dropped onto collagen scaffolds and transplanted into the animal model. Twelve weeks after transplantation, we discovered that the hESC-derived cells could survive and recover the structure and function of uterine horns in a rat model of severe uterine damage. The experimental system presented here provides a reliable protocol to produce endometrium-like cells from hESCs. Our results encourage the use of hESCs in cell-replacement therapy for severe uterine damage in future.

Current progress in xenotransplantation and organ bioengineering

Organ transplantation represents a unique method of treatment to cure people with end-stage organ failure. Since the first successful organ transplant in 1954, the field of transplantation has made great strides forward. However, despite the ability to transform and save lives, transplant surgery is still faced with a fundamental problem the number of people requiring organ transplants is simply higher than the number of organs available. To put this in stark perspective, because of this critical organ shortage 18 people every day in the United States alone die on a transplant waiting list (U.S. Department of Health & Human Services, http://organdonor.gov/about/data.html). To address this problem, attempts have been made to increase the organ supply through xenotransplantation and more recently, bioengineering. Here we trace the development of both fields, discuss their current status and highlight limitations going forward. Ultimately, lessons learned in each field may prove widely applicable and lead to the successful development of xenografts, bioengineered constructs, and bioengineered xeno-organs, thereby increasing the supply of organs for transplantation.

Bioengineering kidneys for transplantation

One in 10 Americans suffers from chronic kidney disease, and close to 90,000 people die each year from causes related to kidney failure. Patients with end-stage renal disease are faced with two options: hemodialysis or transplantation. Unfortunately, the transplantation option is limited because of the shortage of donor organs and the need for immunosuppression. Bioengineered kidney grafts theoretically present a novel solution to both problems. Herein, we discuss the history of bioengineering organs, the current status of bioengineered kidneys, considerations for the future of the field, and challenges to clinical translation. We hope that by integrating principles of tissue engineering, and stem cell and developmental biology, bioengineered kidney grafts will advance the field of regenerative medicine while meeting a critical clinical need.