Tissue-engineered lymphatic graft for the treatment of lymphedema

BACKGROUND: Lymphedema is a chronic debilitating condition and curative treatment is yet to be found. Tissue engineering approach, which combines cellular components, scaffold, and molecular signals hold great potential in the treatment of secondary lymphedema with the advent of lymphatic graft to reconstruct damaged collecting lymphatic vessel. This review highlights the ideal characteristics of lymphatic graft, the limitation and challenges faced, and the approaches in developing tissue-engineered lymphatic graft. METHODS: Literature on tissue engineering of lymphatic system and lymphatic tissue biology was reviewed. RESULTS: The prime challenge in the design and manufacturing of this graft is producing endothelialized conduit with intraluminal valves. Suitable scaffold material is needed to ensure stability and functionality of the construct. Endothelialization of the construct can be enhanced via biofunctionalization and nanotopography, which mimics extracellular matrix. Nanocomposite polymers with improved performance over existing biomaterials are likely to benefit the development of lymphatic graft. CONCLUSIONS: With the in-depth understanding of tissue engineering, nanotechnology, and improved knowledge on the biology of lymphatic regeneration, the aspiration to develop successful lymphatic graft is well achievable

Estrogen/Estrogen Receptor Alpha Signaling in Mouse Posterofrontal Cranial Suture Fusion

BACKGROUND: While premature suture fusion, or craniosynostosis, is a relatively common condition, the cause is often unknown. Estrogens are associated with growth plate fusion of endochondral bones. In the following study, we explore the previously unknown significance of estrogen/estrogen receptor signaling in cranial suture biology. METHODOLOGY/PRINCIPAL FINDINGS: Firstly, estrogen receptor (ER) expression was examined in physiologically fusing (posterofrontal) and patent (sagittal) mouse cranial sutures by quantitative RT-PCR. Next, the cranial suture phenotype of ER alpha and ER beta knockout (alphaERKO, betaERKO) mice was studied. Subsequently, mouse suture-derived mesenchymal cells (SMCs) were isolated; the effects of 17-beta estradiol or the estrogen antagonist Fulvestrant on gene expression, osteogenic and chondrogenic differentiation were examined in vitro. Finally, in vivo experiments were performed in which Fulvestrant was administered subcutaneously to the mouse calvaria. Results showed that increased ERalpha but not ERbeta transcript abundance temporally coincided with posterofrontal suture fusion. The alphaERKO but not betaERKO mouse exhibited delayed posterofrontal suture fusion. In vitro, addition of 17-beta estradiol enhanced both osteogenic and chondrogenic differentiation in suture-derived mesenchymal cells, effects reversible by Fulvestrant. Finally, in vivo application of Fulvestrant significantly diminished calvarial osteogenesis, inhibiting suture fusion. CONCLUSIONS/SIGNIFICANCE: Estrogen signaling through ERalpha but not ERbeta is associated with and necessary for normal mouse posterofrontal suture fusion. In vitro studies suggest that estrogens may play a role in osteoblast and/or chondrocyte differentiation within the cranial suture complex

Superficial temporal recipient vessels in microvascular orbit and scalp reconstruction of oncologic defects.

The superficial temporal artery and vein (STA/V) are often considered suboptimal recipient vessels due to anecdotal reports that they are unreliable and prone to spasm. This is unfortunate, as their position greatly facilitates reconstruction of the scalp and orbit. We present our experience with 28 patients who underwent microvascular craniofacial reconstruction of oncological defects using the STA/V as recipients over a 4-year period at a single institution. Rates of vessel thrombosis, total flap loss, and partial flap loss were not significantly different from 282 flaps anastomosed to neck vessels. With knowledge of the anatomy and proper technique, the STA/V are reliable and available in most patients and can facilitate microvascular orbit and scalp reconstruction. The proximity they offer allows more flexibility in flap pedicle length requirement and avoids the use of vein grafts. Caution should be exercised if there is a history of radiation therapy

Post-reconstruction dermatitis of the breast

BackgroundApproximately one-third of women diagnosed with breast cancer undergo mastectomy with subsequent implant-based or autogenous tissue-based reconstruction. Potential complications include infection, capsular contracture, and leak or rupture of implants with necessity for explantation. Skin rashes are infrequently described complications of patients who undergo mastectomy with or without reconstruction.MethodsA retrospective analysis of breast cancer patients referred to the Dermatology Service for diagnosis and management of a rash post-mastectomy and expander or implant placement or transverse rectus abdominis myocutaneous (TRAM) flap reconstruction was performed. Parameters studied included reconstruction types, time to onset, clinical presentation, associated symptoms, results of microbiologic studies, management, and outcome.ResultsWe describe 21 patients who developed a rash on the skin overlying a breast reconstruction. Average time to onset was 25.7 months after expander placement or TRAM flap reconstruction. Clinical presentations included macules and papules or scaly, erythematous patches and plaques. Five patients had cultures of the rash, which were all negative. Skin biopsy was relatively contraindicated in areas of skin tension, and was reserved for non-responding eruptions. Treatments included topical corticosteroids and topical antibiotics, which resulted in complete or partial responses in all patients with documented follow-ups.ConclusionOur findings suggest that tension and post-surgical factors play a causal role in this hitherto undescribed entity: "post-reconstruction dermatitis of the breast." This is a manageable condition that develops weeks to years following breast reconstruction. Topical corticosteroids and antibiotics result in restoration of skin barrier integrity and decreased secondary infection