Decellularization and genipin crosslinking of amniotic membrane suitable for tissue engineering applications

Abstract

Amniotic membrane has the potential to be used as scaffold in various tissue engineering applications. However, increasing its biostability at the same time maintaining its biocompatibility is important to enhance its usage as a scaffold. This studied characteristics genipin-crosslinked amniotic membrane as a bioscaffold. Redundant human amniotic membranes (HAM) divided into native (nAM), decellularized (dAM) and genipin-crosslinked (clAM) groups. The dAM and clAM group were decellularized using thermolysin (TL) and sodium hydroxide (NaOH) solution. Next, clAM group was crosslinked with 0.5% and 1.0% (w/v) genipin. The HAM was then studied for in vitro degradation, percentage of swelling, optical clarity, ultrastructure and mechanical strength. Meanwhile, fibroblasts isolated from nasal turbinates were then seeded onto nAM, dAM and clAM for biocompatibility studies. clAM had the slowest degradation rate and were still morphologically intact after 30 days of incubation in 0.01% collagenase type 1 solution. The dAM had a significantly highest percentage of swelling than other groups (p?<?0.05). Besides, the dAM retained the collagen content at similar level of nAM. Although the dAM had highest mechanical strength compared to the rest of the groups, the differences were statistically insignificant. Cell attachment on dAM and 0.5% clAM was higher compared to that on nAM and 1.0% clAM. In conclusion, clAM have better biostability and biocompatibility compared to the nAM and dAM. Together with other suitable characteristics of the clAM such as percentage of swelling, structural integrity and ECM content, clAM is suitable as scaffold for various tissue engineering applications.     

Late-presenting complete heart block after pediatric cardiac surgery

Late presenting complete heart block after pediatric cardiac surgery is a rare complication and its management is well defined once the initial diagnosis in made timely and appropriately. In this report we described a child who underwent atrioventricular septal defect repair with a normal sinus rhythm during the postoperative period, as well as during the first 2 years of follow up.She subsequently developed complete heart block with bradycardia that required insertion of a pacemaker. Here we discuss this unusual late-presenting complication, possible risk factors, and management.     

Thiotepa‐based versus total body irradiation‐based myeloablative conditioning prior to allogeneic stem cell transplantation for acute myeloid leukaemia in first complete remission: a retrospective analysis from the Acute Leukemia Working Party of the European Group for Blood and Marrow Transplantation

Thiotepa is an alkylating compound with an antineoplastic and myeloablative activity and can mimic the effect of radiation. However, it is unknown whether this new regimen could safely replace the long‐established ones. This retrospective matched‐pair analysis evaluated the outcome of adults with acute myeloid leukaemia in first complete remission who received myeloablative conditioning either with a thiotepa‐based (n = 121) or a cyclophosphamide/total body irradiation‐based (TBI; n = 358) regimen for allogeneic hematopoietic stem cell transplantation from an HLA‐matched sibling or an unrelated donor. With a median follow‐up of 44 months, the outcome was similar in both groups. Acute graft‐versus‐host disease grade II‐IV was observed in 25% after thiotepa‐containing regimen versus 35% after TBI (P = 0.06). The 2‐yr cumulative incidence of chronic graft‐versus‐host disease was 40.5% for thiotepa and 41% for TBI (P = 0.98). At 2 yrs, the cumulative incidences of non‐relapse mortality and relapse incidence were 23.9% (thiotepa) vs. 22.4% (TBI; P = 0.66) and 17.2% (thiotepa) vs. 23.3% (TBI; P = 0.77), respectively. The probabilities of leukaemia‐free and overall survival at 2 yrs were not significantly different between the thiotepa and TBI groups, at 58.9% vs. 54.2% (P = 0.95) and 61.4% vs. 58% (P = 0.72), respectively. Myeloablative regimens using combinations including thiotepa can provide satisfactory outcomes, but the optimal conditioning remains unclear for the individual patient in this setting.     

Aneurysm formation of pericardial patch in Manouguian procedure

Pericardial patch has been used to repair cardiac defects; however, its strength as an aortoplasty patch to tolerate systemic pressure is a matter of debate. We report an aneurysmal dilatation of pericardial patch in aortoplasty. Our patient was a 56-year-old female known case of rheumatic heart disease that underwent redoes mitral and aortic valve replacements along with Manouguian aortoplasty at the age of 44?years old. After 2?months, she was readmitted with a diagnosis of endocarditis. Echocardiography revealed a small cavity in the posterior wall of the aorta. She responded to medical therapy and discharged in a good condition. Twelve years later, she was scheduled to undergo reoperation due to a severe paraprosthetic aortic valve leakage and a pericardial patch aneurysm. The leaking prosthetic aortic valve was explanted and the aneurysmal tissue was replaced with a polyethylene terephthalate patch.