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Recipient Tissue (recipient + tissue)

Distribution by Scientific Domains

Medical Sciences	60%

Selected Abstracts

Current Concepts of Fat Graft Survival: Histology of Aspirated Adipose Tissue and Review of the Literature

DERMATOLOGIC SURGERY, Issue 12 2000
Boris Sommer MD
Background. Controversy remains about the longevity of correction in autologous fat grafts and its relation to adipocyte survival. Reported long-term fat graft survival rates differ widely, depending on harvesting method, means of reinjection, injection site, and evaluation methods. Objective. To demonstrate histologic findings of aspirated adipose tissue and compare the findings to the reports in the literature. Methods. Review of the literature and the histology of transplanted fat 7 years after subcutaneous implantation and trypan blue staining to determine the vitality of defrosted adipocytes. Results. Fat cells survive aspiration with a suction machine or syringe equally well. Use of a liposuction cannula or 14-gauge needle gives comparable results. Local anesthesia or tumescent local anesthesia is recommended for the donor site, preferably with addition of epinephrine. Conclusion. Clinical longevity of correction after autologous fat transfer is determined by the degree of augmentation resulting from the amount of fibrosis induced and the number of viable fat cells. Survival of aspirated fat cell grafts depends mainly on the anatomic site, the mobility and vascularity of the recipient tissue, or underlying causes and diseases, and less on harvesting and reinjection methods. [source]

Iris as a recipient tissue for pigment cells: Organized in vivo differentiation of melanocytes and pigmented epithelium derived from embryonic stem cells in vitro

DEVELOPMENTAL DYNAMICS, Issue 9 2008
Hitomi Aoki
Abstract Regenerative transplantation of embryonic stem (ES) cell-derived melanocytes into adult tissues, especially skin that includes hair follicles or the hair follicle itself, generally not possible, whereas that of ES cell-derived pigmented epithelium was reported previously. We investigated the in vivo differentiation of these two pigment cell types derived from ES cells after their transfer into the iris. Melanocytes derived from ES cells efficiently integrated into the iris and expanded to fill the stromal layer of the iris, like those prepared from neonatal skin. Transplanted pigmented epithelium from either ES cells or the neonatal eye was also found to be integrated into the iris. Both types of these regenerated pigment cells showed the correct morphology. Regenerated pigment epithelium expressed its functional marker. Functional blocking of signals required for melanocyte development abolished the differentiation of transplanted melanocytes. These results indicate successful in vivo regenerative transfer of pigment cells induced from ES cells in vitro. Developmental Dynamics 237:2394,2404, 2008. © 2008 Wiley-Liss, Inc. [source]

Wet-Spun Biodegradable Fibers on Conducting Platforms: Novel Architectures for Muscle Regeneration

ADVANCED FUNCTIONAL MATERIALS, Issue 21 2009
Joselito M. Razal
Abstract Novel biosynthetic platforms supporting ex vivo growth of partially differentiated muscle cells in an aligned linear orientation that is consistent with the structural requirements of muscle tissue are described. These platforms consist of biodegradable polymer fibers spatially aligned on a conducting polymer substrate. Long multinucleated myotubes are formed from differentiation of adherent myoblasts, which align longitudinally to the fiber axis to form linear cell-seeded biosynthetic fiber constructs. The biodegradable polymer fibers bearing undifferentiated myoblasts can be detached from the substrate following culture. The ability to remove the muscle cell-seeded polymer fibers when required provides the means to use the biodegradable fibers as linear muscle-seeded scaffold components suitable for in vivo implantation into muscle. These fibers are shown to promote differentiation of muscle cells in a highly organized linear unbranched format in vitro and thereby potentially facilitate more stable integration into recipient tissue, providing structural support and mechanical protection for the donor cells. In addition, the conducting substrate on which the fibers are placed provides the potential to develop electrical stimulation paradigms for optimizing the ex vivo growth and synchronization of muscle cells on the biodegradable fibers prior to implantation into diseased or damaged muscle tissue. [source]

Influence of implantation interval on the long-term biocompatibility of surgical mesh

BRITISH JOURNAL OF SURGERY (NOW INCLUDES EUROPEAN JOURNAL OF SURGERY), Issue 8 2002
Dr B. Klosterhalfen
Background: The aim was to study the long-term tissue response to polypropylene mesh. Methods: This was a retrieval study that investigated 76 polypropylene meshes with a median implantation interval of 18 (range 2,180) months. Mesh was explanted following hernia recurrence, infection or pain. The median implantation interval was 20 (range 4,180) months in the recurrence group, 30 (range 5,48) months in the pain group and 10 (range 2,56) months in the infection group (P < 0·05, infection versus pain or recurrence). The inflammatory response was determined by immunohistochemistry of macrophages (CD68), polymorphonuclear granulocytes (CD15) and T and B lymphocytes (CD3 and CD20). The cell turnover within the interface mesh fibre,recipient tissue was measured by TUNEL for apoptosis or DNA strand breaks, Ki67 for cell proliferation and heat-shock protein (HSP) 70 for cell stress. Results: With the exception of HSP-70, levels of all variables decreased over time. Sex, age, type of previous operation or location of the mesh did not have a significant influence. Conclusion: Long-term incorporated polypropylene mesh in humans has a more favourable tissue response with increasing implantation interval. © 2002 British Journal of Surgery Society Ltd [source]

Bone Marrow-Derived Cells Implanted into Freeze-Injured Urinary Bladders Reconstruct Functional Smooth Muscle Layers

LUTS, Issue 1 2010
Tetsuya IMAMURA
Regenerative medicine offers great hope for lower urinary tract dysfunctions due to irreversibly damaged urinary bladders and urethras. Our aim is the utilization of bone marrow-derived cells to reconstruct smooth muscle layers for the treatments of irreversibly damaged lower urinary tracts. In our mouse model system for urinary bladder regeneration, the majority of smooth muscle layers in about one-third of the bladder are destroyed by brief freezing. Three days after wounding, we implant cultured cells derived from bone marrow. The implanted bone marrow-derived cells survive and differentiate into layered smooth muscle structures that remediate urinary dysfunction. However, bone marrow-derived cells implanted into the intact normal urinary bladders do not exhibit these behaviors. The presence of large pores in the walls of the freeze-injured urinary bladders is likely to be helpful for a high rate of survival of the implanted cells. The pores could also serve as scaffolding for the reconstruction of tissue structures. The surviving host cells upregulate several growth factor mRNAs that, if translated, can promote differentiation of smooth muscle and other cell types. We conclude that the multipotency of the bone marrow-derived cells and the provision of scaffolding and suitable growth factors by the microenvironment enable successful tissue engineering in our model system for urinary bladder regeneration. In this review, we suggest that the development of regenerative medicine needs not only a greater understanding of the requirements for undifferentiated cell proliferation and targeted differentiation, but also further knowledge of each unique microenvironment within recipient tissues. [source]