Jhade D. Woodall

Recellularization via the bile duct supports functional allogenic and xenogenic cell growth on a decellularized rat liver scaffold

ABSTRACT Recent years have seen a proliferation of methods leading to successful organ decellularization. In this experiment we examine the feasibility of a decellularized liver construct to support growth of functional multilineage cells. Bio-chamber systems were used to perfuse adult rat livers with 0.1% SDS for 24 hours yielding decellularized liver scaffolds. Initially, we recellularized liver scaffolds using a human tumor cell line (HepG2, introduced via the bile duct). Subsequent studies were performed using either human tumor cells co-cultured with human umbilical vein endothelial cells (HUVECs, introduced via the portal vein) or rat neonatal cell slurry (introduced via the bile duct). Bio-chambers were used to circulate oxygenated growth medium via the portal vein at 37C for 5-7 days. Human HepG2 cells grew readily on the scaffold (n = 20). HepG2 cells co-cultured with HUVECs demonstrated viable human endothelial lining with concurrent hepatocyte growth (n = 10). In the series of neonatal cell slurry infusion (n = 10), distinct foci of neonatal hepatocytes were observed to repopulate the parenchyma of the scaffold. The presence of cholangiocytes was verified by CK-7 positivity. Quantitative albumin measurement from the grafts showed increasing albumin levels after seven days of perfusion. Graft albumin production was higher than that observed in traditional cell culture. This data shows that rat liver scaffolds support human cell ingrowth. The scaffold likewise supported the engraftment and survival of neonatal rat liver cell slurry. Recellularization of liver scaffolds thus presents a promising model for functional liver engineering.

Large Animal Models for Vascularized Composite Allotransplantation

Large animal models have served as the foundation for clinical trials in all solid organ transplantation. Likewise, pre-clinical studies in vascularized composite allotransplantation (VCA) have provided a foundation for initial human applications in VCA. The growth of clinical VCA correspondingly benefits from large animal studies investigating the unique immunobiology, improved immunosuppressive regimens, and the potential induction of immunologic tolerance. VCA studies in large animal models of nonhuman primates, swine, and canines have and continue to build knowledge towards improved clinical outcomes.

Infused Bone Marrow Fails to Prevent Vascularized Composite Allograft Rejection in Nonhuman Primates

Vascular composite allografts (VCA) are highly antigenic as demonstrated by near universal rejection rates. Nonetheless, substantial immunosuppressive therapy has permitted VCA to survive currently between 10 (face) and 15 (hand) years. The field of VCA has placed major emphasis on investigating in preclinical and clinical trials whether infused bone marrow combined with standard immunosuppression may improve immunologic outcomes. In contrast to solid organ transplant protocols utilizing bone marrow cells (BMC) and nonmyeloblative conditioning, tolerance (or even the absence of rejection on immunosuppression) has not been observed in any VCA trials (1–3). The lack of controlled trials directly evaluating infused BMC as a cellular adjunct leads to ongoing ambiguity regarding the role of BMC infusion without preconditioning in VCA (4).

Early Microchimerism After Face Transplantation Detected by Quantitative Real-time Polymerase Chain Reaction of Insertion/Deletion Polymorphisms.

V composite allografts (VCA), such as hand and face transplants, offer an alternative approach to complex reconstructive scenarios that otherwise require multiple complex operations. Multiple face transplants with various components of skin, muscle, and bone have been performed worldwide, with the most extensive including mandible and maxilla, tongue, and skin performed in 2012 at the University of Maryland Medical Center. Microchimerism, defined as the presence of low levels of donor-derived cells (<1%), has not been definitively associated with improved immunologic outcomes. We investigated the presence of chimerism in our clinical full-face VCA with upper and lower jaw vascularized bone marrow components using established techniques of flow cytometry and short tandem repeat analysis without detecting any evidence of macrochimerism. We subsequently analyzed postoperative whole blood samples from our face transplant recipient using a commercial assay (AlleleSEQR) that screens and quantifies DNA by quantitative polymerase chain reaction (PCR) using insertion/deletion (InDel) polymorphisms as genetic markers sensitive to 0.001%.

Cosmetic Surgery Training in Plastic Surgery Residency Programs

Background: Over the past decade, plastic surgery programs have continued to evolve with the addition of 1 year of training, increase in the minimum number of required aesthetic cases, and the gradual replacement of independent positions with integrated ones. To evaluate the impact of these changes on aesthetic training, a survey was sent to residents and program directors. Methods: A 37 question survey was sent to plastic surgery residents at all Accreditation Council for Graduate Medical Education–approved plastic surgery training programs in the United States. A 13 question survey was sent to the program directors at the same institutions. Both surveys were analyzed to determine the duration of training and comfort level with cosmetic procedures. Results: Eighty-three residents (10%) and 11 program directors (11%) completed the survey. Ninety-four percentage of residents had a dedicated cosmetic surgery rotation (an increase from 68% in 2015) in addition to a resident cosmetic clinic. Twenty percentage of senior residents felt they would need an aesthetic surgery fellowship to practice cosmetic surgery compared with 31% in 2015. Integrated chief residents were more comfortable performing cosmetic surgery cases compared with independent chief residents. Senior residents continue to have poor confidence with facial aesthetic and body contouring procedures. Conclusions: There is an increase in dedicated cosmetic surgery rotations and fewer residents believe they need a fellowship to practice cosmetic surgery. However, the comfort level of performing facial aesthetic and body contouring procedures remains low particularly among independent residents.

Vascularized Composite Allotransplantation: Medical Complications

The objective of this review is to summarize the collective knowledge regarding the risks and complications in vascularized composite tissue allotransplantation (VCA), focusing on upper extremity and facial transplantation. The field of VCA has entered its second decade with an increasing experience in both the impressive good outcomes, as well as defining challenges, risks, and experienced poor results. The limited and selective publishing of negative outcomes in this relatively new field makes it difficult to conclusively evaluate outcomes of graft and patient survival and morbidities. Therefore, published data, conference proceedings, and communications were summarized in an attempt to provide a current outline of complications. These data on the medical complications of VCA should allow for precautions to avoid poor outcomes, data to better provide informed consent to potential recipients, and result in improvements in graft and patient outcomes as VCA finds a place as a therapeutic option for selected patients.

Lost in translation? Microchimersim detection in experimental and clinical transplantation

Abstract The importance of further elucidating the properties surrounding microchimerism in various experi- mental models and clinical transplantation are limited by current techniques and the sensitivity of available platforms. Development of reliable methods and use routine use of microchimerism detection in clinical practice could guide clinical decision making regarding rejection, stable function, and tolerance.