Assessment of kidney quality before harvesting. Review of contemporary donor risk indexes

Transplantacja nerki jest najlepszą metodą leczenia nerkozastępczego u pacjentów ze schyłkową niewydolnością nerek. Z powodu niewystarczającej liczby dawców na całym świecie obserwuje się wydłużanie list pacjentów oczekujących na przeszczepienie. Wczesna identyfikacja nerek gorszej jakości daje możliwość przeprowadzenia kolejnych etapów procedury transplantacyjnej w taki sposób, aby zmniejszyć ryzyko powikłań u biorcy oraz wydłużyć przeżywalność przeszczepionego narządu. Służą temu różne systemy oceny dawców prowadzone na etapie akceptacji narządów do pobrania. Jak dotąd nie udało się wyodrębnić optymalnej skali oceny dawcy, która miałaby wyraźną przewagę pod względem mocy rokowniczej oraz stanowiłaby wspólną podstawę do porównywania i ulepszania wyników przeszczepiania. Jednym z nowszych i bardziej obiektywnych indeksów ryzyka jest KDRI (Kidney Donor Risk Index), który został opracowany przez grupę Rao w 2009 roku i stał się podstawą nowego systemu alokacji nerek w Stanach Zjednoczonych.One of the key issues in contemporary transplantology is an objective assessment of a kidney donor to be performed before accepting the organ for transplantation. There have been various attempts at creating a numerical scale, based on donor, recipient, histological or machine perfusion parameters, to evaluate the quality of kidneys harvested from cadaver donors. Some of these were based on large populations of donor-recipient pairs and have been accepted by local organ allocation systems. As of yet none has been endorsed by international institutions a universal predictive model of graft function nor provided a uniform platform to initiate and to compare clinical studies. Originally proposed by Rao et al in 2009, the Kidney Donor Risk Index (KDRI) is a prediction model that assigns a continuous risk score to deceased donor kidneys, based on a donor and a transplant characteristics collected by the Organ Procurement and Transplantation Network (OPTN). The new kidney allocation system implemented in the US rates the harvested organs, based on KDRI. So far, few publications covered an assessment of the importance of risk KDRI for population recipients in other countries and it is also not known whether it is also an adequate prognostic tool for polish population of recipients

Chitosan as an Underrated Polymer in Modern Tissue Engineering

Chitosan is one of the most well-known and characterized materials applied in tissue engineering. Due to its unique chemical, biological and physical properties chitosan is frequently used as the main component in a variety of biomaterials such as membranes, scaffolds, drug carriers, hydrogels and, lastly, as a component of bio-ink dedicated to medical applications. Chitosan’s chemical structure and presence of active chemical groups allow for modification for tailoring material to meet specific requirements according to intended use such as adequate endurance, mechanical properties or biodegradability time. Chitosan can be blended with natural (gelatin, hyaluronic acid, collagen, silk, alginate, agarose, starch, cellulose, carbon nanotubes, natural rubber latex, κ-carrageenan) and synthetic (PVA, PEO, PVP, PNIPPAm PCL, PLA, PLLA, PAA) polymers as well as with other promising materials such as aloe vera, silica, MMt and many more. Chitosan has several derivates: carboxymethylated, acylated, quaternary ammonium, thiolated, and grafted chitosan. Its versatility and comprehensiveness are confirming by further chitosan utilization as a leading constituent of innovative bio-inks applied for tissue engineering. This review examines all the aspects described above, as well as is focusing on a novel application of chitosan and its modifications, including the 3D bioprinting technique which shows great potential among other techniques applied to biomaterials fabrication

Nursing care of patients with diabetes complications qualify to pancreatic islet transplantation

W Polsce żyje około 2,5 miliona chorych na cukrzycę. Wyizolowanie insuliny w 1921 roku umożliwiło wydłużenie życia chorym na cukrzycę, nie uchroniło jednak przed rozwojem wtórnych powikłań cukrzycy, takich jak nefropatia, retinopatia, mikro- i makroangiopatia. Przełomem w leczeniu samej cukrzycy i leczeniu jej powikłań stało się przeszczepienie trzustki. Alternatywą dla chorych, którzy przeważnie z powodu zbyt nasilonych powikłań kardiologicznych nie mogą być poddani temu zabiegowi, jest przeszczepienie wysp trzustkowych. Celem pracy jest przedstawienie problemów zdrowotnych chorych z powikłaniami cukrzycy, kwalifikowanych do alloprzeszczepienia wysp trzustkowych. Allotransplantacja izolowanych wysp trzustki jest wskazana w cukrzycy typu 1. Minimalny czas trwania cukrzycy u chorych, którzy mogą zostać rozpatrywani jako potencjalni beneficjenci tego typu leczenia, wynosi 5 lat. Chorymi kwalifikowanymi do alloprzeszczepienia wysp trzustkowych mogą zostać pacjenci ze stężeniem peptydu C poniżej 0,05 ng/ml na czczo. Jako biorców rozpatruje się trzy grupy chorych — chorzy z chwiejną cukrzycą bez nefropatii cukrzycowej (grupa 1), chorzy z nefropatią cukrzycową (grupa 2), chorzy z nefropatią cukrzycową po przeszczepieniu nerki (grupa 3). W grupie pierwszej dominują problemy związane z występującymi epizodami hipoglikemicznymi, w grupie drugiej są one związane z rozwijającą się niewydolnością nerek, w grupie trzeciej charakterystyczne są problemy związane ze stosowaną immunosupresją po przeszczepieniu nerki. Pacjenci z wieloletnią cukrzycą i rozwijającymi się powikłaniami, którzy są poddawani procesowi kwalifikacji do alloprzeszczepienia wysp trzustkowych, są chorymi wymagającymi wyjątkowej uwagi pielęgniarskiej ze względu na szeroką gamę problemów zdrowotnych.There are 2,5 million diabetics in Poland. Isolation of insulin in 1921 gave a possibility to prolong diabetic’s life however many complications, such as: nephropathy, retinopathy, micro and macroangiopathy may occur. The program of pancreas transplantation was a turning point in diabetes treatment. Pancreatic islet transplantation is an alternative method for patients non suitable for surgical treatment due to cardiological complications. The aim of this paper was to define health problems of patients with diabetes complications qualified to pancreatic islet allotransplantation. Pancreatic islet allotransplantation is performed in type 1 diabetes. Patients considered for this treatment must suffer from diabetes for at least 5 years and the level of peptic C should be below 0.05 ng/ml. Patients are divided into 3 groups: 1. non stable diabetes, hypoglycemia and nephropathy; 2. nephropathy with renal failure; 3. nephropathy and immunosupression complications after kidney transplantation. In the first group problems related with hypoglycaemic episodes are dominant. Main concern in the second group is developing kidney insufficiency. Major problem In the third is immunosupression applied after kidney transplantation. Patients who have been suffering from diabetes for at least 5 years are considered to pancreatic islet allotransplantation. They are a special group of patients with many specific complications and they need a professional nursing care

Impact of Porcine Pancreas Decellularization Conditions on the Quality of Obtained dECM

Due to the limited number of organ donors, 3D printing of organs is a promising technique. Tissue engineering is increasingly using xenogeneic material for this purpose. This study was aimed at assessing the safety of decellularized porcine pancreas, together with the analysis of the risk of an undesirable immune response. We tested eight variants of the decellularization process. We determined the following impacts: rinsing agents (PBS/NH3·H2O), temperature conditions (4 °C/24 °C), and the grinding method of native material (ground/cut). To assess the quality of the extracellular matrix after the completed decellularization process, analyses of the following were performed: DNA concentration, fat content, microscopic evaluation, proteolysis, material cytotoxicity, and most importantly, the Triton X-100 content. Our analyses showed that we obtained a product with an extremely low detergent content with negligible residual DNA content. The obtained results confirmed the performed histological and immuno-fluorescence staining. Moreover, the TEM microscopic analysis proved that the correct collagen structure was preserved after the decellularization process. Based on the obtained results, we chose the most favorable variant in terms of quality and biology. The method we chose is an effective and safe method that gives a chance for the development of transplant and regenerative medicine

Impact of Porcine Pancreas Decellularization Conditions on the Quality of Obtained dECM

Due to the limited number of organ donors, 3D printing of organs is a promising technique. Tissue engineering is increasingly using xenogeneic material for this purpose. This study was aimed at assessing the safety of decellularized porcine pancreas, together with the analysis of the risk of an undesirable immune response. We tested eight variants of the decellularization process. We determined the following impacts: rinsing agents (PBS/NH3·H2O), temperature conditions (4 °C/24 °C), and the grinding method of native material (ground/cut). To assess the quality of the extracellular matrix after the completed decellularization process, analyses of the following were performed: DNA concentration, fat content, microscopic evaluation, proteolysis, material cytotoxicity, and most importantly, the Triton X-100 content. Our analyses showed that we obtained a product with an extremely low detergent content with negligible residual DNA content. The obtained results confirmed the performed histological and immuno-fluorescence staining. Moreover, the TEM microscopic analysis proved that the correct collagen structure was preserved after the decellularization process. Based on the obtained results, we chose the most favorable variant in terms of quality and biology. The method we chose is an effective and safe method that gives a chance for the development of transplant and regenerative medicine

Bionic Organs: Shear Forces Reduce Pancreatic Islet and Mammalian Cell Viability during the Process of 3D Bioprinting

Background: 3D bioprinting is the future of constructing functional organs. Creating a bioactive scaffold with pancreatic islets presents many challenges. The aim of this paper is to assess how the 3D bioprinting process affects islet viability. Methods: The BioX 3D printer (Cellink), 600 μm inner diameter nozzles, and 3% (w/v) alginate cell carrier solution were used with rat, porcine, and human pancreatic islets. Islets were divided into a control group (culture medium) and 6 experimental groups (each subjected to specific pressure between 15 and 100 kPa). FDA/PI staining was performed to assess the viability of islets. Analogous studies were carried out on α-cells, β-cells, fibroblasts, and endothelial cells. Results: Viability of human pancreatic islets was as follows: 92% for alginate-based control and 94%, 90%, 74%, 48%, 61%, and 59% for 15, 25, 30, 50, 75, and 100 kPa, respectively. Statistically significant differences were observed between control and 50, 75, and 100 kPa, respectively. Similar observations were made for porcine and rat islets. Conclusions: Optimal pressure during 3D bioprinting with pancreatic islets by the extrusion method should be lower than 30 kPa while using 3% (w/v) alginate as a carrier