Adverse effects of topical corticosteroids in paediatric eczema: Australasian consensus statement.

Atopic eczema is a chronic inflammatory disease affecting about 30% of Australian and New Zealand children. Severe eczema costs over AUD 6000/year per child in direct medical, hospital and treatment costs as well as time off work for caregivers and untold distress for the family unit. In addition, it has a negative impact on a child's sleep, education, development and self-esteem. The treatment of atopic eczema is complex and multifaceted but a core component of therapy is to manage the inflammation with topical corticosteroids (TCS). Despite this, TCS are often underutilised by many parents due to corticosteroid phobia and unfounded concerns about their adverse effects. This has led to extended and unnecessary exacerbations of eczema for children. Contrary to popular perceptions, (TCS) use in paediatric eczema does not cause atrophy, hypopigmentation, hypertrichosis, osteoporosis, purpura or telangiectasia when used appropriately as per guidelines. In rare cases, prolonged and excessive use of potent TCS has contributed to striae, short-term hypothalamic-pituitary-adrenal axis alteration and ophthalmological disease. TCS use can also exacerbate periorificial rosacea. TCS are very effective treatments for eczema. When they are used to treat active eczema and stopped once the active inflammation has resolved, adverse effects are minimal. TCS should be the cornerstone treatment of atopic eczema in children.

Growth differentiation factor-5 enhances in vitro mesenchymal stromal cell chondrogenesis and hypertrophy.

The regenerative potential for adult bone marrow-derived mesenchymal stromal cells (MSCs) has been extensively investigated in the setting of arthritic disease and focal cartilage defects. In vitro chondrogenic differentiation of MSCs is regularly accomplished by the widely used pellet culture system where MSCs are maintained in high-density pellets to mimic mesenchymal condensation during development. Supplementation of chondrogenic MSC pellet cultures with growth differentiation factor-5 (GDF-5), a highly regulated gene in the chondrogenic phase of endochondral ossification (EO), was investigated here under the hypothesis that GDF-5 will enhance the chondrogenic differentiation of MSCs, thereby supporting their entry into ossification. The supplementation of chondrogenic MSC pellets with the recombinant human GDF-5 protein significantly enhanced MSC chondrogenic differentiation, as demonstrated by enhanced collagen type II and sulfated glycosaminoglycan (GAG) incorporation into the extracellular matrix. Increased P-SMADs 1-5-8 were observed in pellets treated with GDF-5 and transforming growth factor (TGF)-ß 3 when compared to the pellets treated with TGF-ß 3 alone, demonstrated by immunostaining and western blot analysis of the chondrogenic pellet extract. A concurrent increase in alkaline phosphatase, collagen types I and X, and osteopontin secretion indicated a transition of these cultures to hypertrophy. Together, these data support the application of GDF-5 to enhance MSC chondrogenic differentiation and hypertrophy as a precursor to EO.

Topical administration of allogeneic mesenchymal stromal cells seeded in a collagen scaffold augments wound healing and increases angiogenesis in the diabetic rabbit ulcer.

There is a critical clinical need to develop therapies for nonhealing diabetic foot ulcers. Topically applied mesenchymal stromal cells (MSCs) provide a novel treatment to augment diabetic wound healing. A central pathological factor in nonhealing diabetic ulcers is an impaired blood supply. It was hypothesized that topically applied allogeneic MSCs would improve wound healing by augmenting angiogenesis. Allogeneic nondiabetic bone-marrow derived MSCs were seeded in a collagen scaffold. The cells were applied to a full-thickness cutaneous wound in the alloxan-induced diabetic rabbit ear ulcer model in a dose escalation fashion. Percentage wound closure and angiogenesis at 1 week was assessed using wound tracings and stereology, respectively. The topical application of 1,000,000 MSCs on a collagen scaffold demonstrated increased percentage wound closure when compared with lower doses. The collagen and collagen seeded with MSCs treatments result in increased angiogenesis when compared with untreated wounds. An improvement in wound healing as assessed by percentage wound closure was observed only at the highest cell dose. This cell-based therapy provides a novel therapeutic strategy for increasing wound closure and augmenting angiogenesis, which is a central pathophysiological deficit in the nonhealing diabetic foot ulcer.

The electrical stimulation of carbon nanotubes to provide a cardiomimetic cue to MSCs.

Once damaged, cardiac muscle has little intrinsic repair capability due to the poor regeneration potential of remaining cardiomyocytes. One method of overcoming this issue is to deliver functional cells to the injured myocardium to promote repair. To address this limitation we sought to test the hypothesis that electroactive carbon nanotubes (CNT) could be employed to direct mesenchymal stem cell (MSC) differentiation towards a cardiomyocyte lineage. Using a two-pronged approach, MSCs exposed to medium containing CNT and MSCs seeded on CNT based polylactic acid scaffolds were electrically stimulated in an electrophysiological bioreactor. After electrical stimulation the cells reoriented perpendicular to the direction of the current and adopted an elongated morphology. Using qPCR, an upregulation in a range of cardiac markers was detected, the greatest of which was observed for cardiac myosin heavy chain (CMHC), where a 40-fold increase was observed for the electrically stimulated cells after 14 days, and a 12-fold increase was observed for the electrically stimulated cells seeded on the PLA scaffolds after 10 days. Differentiation towards a cardioprogenitor cell was more evident from the western blot analysis, where upregulation of Nkx2.5, GATA-4, cardiac troponin t (CTT) and connexin43 (C43) was seen to occur. This was echoed in immunofluorescent staining, where increased levels of CTT, CMHC and C43 protein expression were observed after electrical stimulation for both cells and cell-seeded scaffolds. More interestingly, there was evidence of increased cross talk between the cells as shown by the pattern of C43 staining after electrical stimulation. These results establish a paradigm for nanoscale biomimetic cues that can be readily translated to other electroactive tissue repair applications.

In vitro characterization of an electroactive carbon-nanotube-based nanofiber scaffold for tissue engineering.

In an effort to reduce organ replacement and enhance tissue repair, there has been a tremendous effort to create biomechanically optimized scaffolds for tissue engineering applications. In contrast, the development and characterization of electroactive scaffolds has attracted little attention. Consequently, the creation and characterization of a carbon nanotube based poly(lactic acid) nanofiber scaffold is described herein. After 28 d in physiological solution at 37 °C, a change in the mass, chemical properties and polymer morphology is seen, while the mechanical properties and physical integrity are unaltered. No adverse cytotoxic affects are seen when mesenchymal stem cells are cultured in the presence of the scaffold. Taken together, these data auger well for electroactive tissue engineering.

Carbon nanotubes and mesenchymal stem cells: biocompatibility, proliferation and differentiation.

The synergy of the unique properties of carbon nanotubes (CNT) with the remarkable potential of human mesenchymal stem cells (hMSC) provides an exciting opportunity for novel therapeutic modalities. However, little is known about the impact of CNT on hMSC behavior. We report the effect of CNT on hMSC renewal, metabolic activity, and differentiation. Furthermore, we tracked the intracellular movement of CNT through the cytoplasm to a nuclear location and assessed effects on cellular ultra structure.