Alfred T. Lane

Human COL7A1-corrected induced pluripotent stem cells for the treatment of recessive dystrophic epidermolysis bullosa

Patient-specific iPSCs were derived, corrected, and differentiated into human skin grafts for the treatment of recessive dystrophic epidermolysis bullosa. Patient-Specific Stem Cell Therapy for Rare Skin Disease Recessive dystrophic epidermolysis bullosa (RDEB) is characterized by a mutation in the COL7A1 gene, which causes severe skin fragility and blistering. Although rare, patients with RDEB spend their lives in pain, fearful of even the slightest amount of friction. There are no cures for this disease, but cell therapy represents a viable option, as demonstrated by Sebastiano et al. in this issue. The authors took skin biopsies from three adult patients with RDEB and generated induced pluripotent stem cells, or iPSCs, from the keratinocytes (skin cells) and fibroblasts present in the tissue. The COL7A1 mutation in the iPSCs was corrected using a new adeno-associated viral approach. The genetically repaired iPSCs were screened to make sure they did not have any genes associated with squamous cell carcinoma—a cancer common to RDEB patients—and were then differentiated into keratinocytes that expressed full-length wild-type collagen VII protein. In vitro and in vivo in mice, these “corrected” keratinocytes were able to form sheets of skin with a defined layer of collagen VII. Although the skin grafts only lasted for 3 weeks, and further testing is needed in a disease model, the ability to correct and bank a patient’s own cells and to select “clean” iPSCs represents an important step forward in devising a treatment for those affected by RDEB. Patients with recessive dystrophic epidermolysis bullosa (RDEB) lack functional type VII collagen owing to mutations in the gene COL7A1 and suffer severe blistering and chronic wounds that ultimately lead to infection and development of lethal squamous cell carcinoma. The discovery of induced pluripotent stem cells (iPSCs) and the ability to edit the genome bring the possibility to provide definitive genetic therapy through corrected autologous tissues. We generated patient-derived COL7A1-corrected epithelial keratinocyte sheets for autologous grafting. We demonstrate the utility of sequential reprogramming and adenovirus-associated viral genome editing to generate corrected iPSC banks. iPSC-derived keratinocytes were produced with minimal heterogeneity, and these cells secreted wild-type type VII collagen, resulting in stratified epidermis in vitro in organotypic cultures and in vivo in mice. Sequencing of corrected cell lines before tissue formation revealed heterogeneity of cancer-predisposing mutations, allowing us to select COL7A1-corrected banks with minimal mutational burden for downstream epidermis production. Our results provide a clinical platform to use iPSCs in the treatment of debilitating genodermatoses, such as RDEB.

Skin benefits from continuous topical administration of a zinc oxide/petrolatum formulation by a novel disposable diaper

Diaper dermatitis is a common childhood affliction. Aiming to help reduce the prevalence of this problem, we have advanced in our development of a novel diaper that delivers dermatological formulations to help protect the skin from over‐hydration and irritation.

Sildenafil for severe lymphatic malformations.

Lymphatic malformations are rare but can cause significant clinical problems in addition to cosmetic disfigurement. Sildenafil was used in a child whose pulmonary hypertension was caused by lymphatic malformation; the result was a marked decrease in the lymphatic malformation.

Long-Term Type VII Collagen Restoration to Human Epidermolysis Bullosa Skin Tissue

In spite of advances in the molecular diagnosis of recessive dystrophic epidermolysis bullosa (RDEB), an inherited blistering disease due to a deficiency of type VII collagen at the basement membrane zone (BMZ) of stratified epithelium, current therapy is limited to supportive palliation. Gene delivery has shown promise in short-term experiments; however, its long-term sustainability through multiple turnover cycles in human tissue has awaited confirmation. To characterize approaches for long-term genetic correction, retroviral vectors were constructed containing long terminal repeat-driven full-length and epitope-tagged COL7A1 cDNA and evaluated for durability of type VII collagen expression and function in RDEB skin tissue regenerated on immune-deficient mice. Type VII collagen expression was maintained for 1 year in vivo, or over 12 epidermal turnover cycles, with no abnormalities in skin morphology or self-renewal. Type VII collagen restoration led to correction of RDEB disease features, including reestablishment of anchoring fibrils at the BMZ. This approach confirms durably corrective and noninjurious gene delivery to long-lived epidermal progenitors and provides the foundation for a human clinical trial of ex vivo gene delivery in RDEB.

Semipermeable dressings improve epidermal barrier function in premature infants.

ABSTRACT: Infants of less than 32 wk gestation have a defective epidermal barrier, with increased skin permeability and transepidermal water loss (TEWL). We studied the effect of a nonadhesive semipermeable dressing on the epidermal barrier of premature infants and on fetal skin transplanted to nude mice. Fifteen infants with a mean estimated gestational age of 27.7 wk and 16 human fetal skin grafts (estimated gestational age, 23–26 wk) transplanted to eight nude mice were studied. One lower leg (or skin graft) was treated and the other left untreated as a control. In the infants, TEWL was measured on control skin and treated skin (both through the dressing and after temporary dressing removal) on d 0, 1,2, 4, and 7. Bacterial and fungal cultures were also performed. In the mice, TEWL and skin blood flow were measured on d 0, 2, and 4. Biopsies were obtained on d 4 for a cell proliferation assay, histology, and electron microscopy. Treated infant skin showed a consistently lower bacterial number and a significantly decreased TEWL (measured through the dressing). There was also a significantly lower TEWL on the treated side, measured after temporary dressing removal, on d 1, 2, 4, and 7, documenting improved epidermal barrier function. The animal study revealed decreased TEWL and a nearly 2-fold greater d-4 keratinocytc proliferation (p = 0.01) in treated skin and decreased blood flow on d 4 in control skin (p = 0.01). There was no significant difference in the volume density of membrane coating granules or the morphology of intcrcorneocyte spaces. It is concluded that semipermeable dressings improve epidermal barrier function without increasing bacterial or fungal colonization in premature infants, and that increased cellular proliferation is associated with improved barrier function in semipermeable dressing-treated fetal skin.

Neonatal skin care: the scientific basis for practice.

Objective: To review the literature addressing the care of neonatal skin. Data Sources: Computerized searches in MEDLINE and CINAHL, as well as references cited in articles reviewed. Key concepts in the searches included neonatal skin differences; neonatal skin and care practices for skin integrity; neonatal skin and toxicity; permeability; and contact irritant sensitization. Study Selection: Articles and comprehensive works relevant to key concepts and published after 1963, with an emphasis on new findings from 1993 to 1999. One hundred two citations were identified as useful to this review. Data Extraction: Data were extracted and organized under the following headings: anatomy and physiology of the skin; physiologic and anatomic differences in neonatal skin; nutritional deficiencies; skin care practices; and care of skin breakdown. Data Synthesis: Newborns’ skin is at risk for disruption of normal barrier function because of trauma. In light of available evidence about differences in neonatal skin development, clinical practice guidelines are suggested for baths, lubrication, antimicrobial skin disinfection, and adhesive removal. In addition, basic care practices are suggested for maintaining skin integrity, reducing exposure to potentially toxic substances, and promoting skin health beyond the neonatal period. Preventive care recommendations are made for reducing trauma, protecting the skin’s immature barrier function, and promoting skin integrity. Conclusions: This review generated evidence with which to create a new and comprehensive practice guideline for clinicians. Evaluation of the guideline is under way at 58 U.S. sites.

An open-label study to evaluate sildenafil for the treatment of lymphatic malformations

BACKGROUND Lymphatic malformations can be challenging to treat. Mainstay interventions including surgery and sclerotherapy are invasive and can result in local recurrence and complications. OBJECTIVE We sought to assess the effect of 20 weeks of oral sildenafil on reducing lymphatic malformation volume and symptoms in children. METHODS Seven children (4 boys, 3 girls; ages 13-85 months) with lymphatic malformations were given oral sildenafil for 20 weeks in this open-label study. The volume of the lymphatic malformation was calculated blindly using magnetic resonance imaging performed before and after 20 weeks of sildenafil. Lymphatic malformations were assessed clinically on weeks 4, 12, 20, and 32. Both the physician and parents evaluated the lymphatic malformation in comparison with baseline. RESULTS Four subjects had a lymphatic malformation volume decrease (1.0%-31.7%). In 2 subjects, despite a lymphatic malformation volume increase (1.1%-3.7%), clinical improvement was noted while on sildenafil. One subject had a 29.6% increase in lymphatic malformation volume and no therapeutic response. Lymphatic malformations of all 6 subjects who experienced a therapeutic response on sildenafil softened and became easily compressible. Adverse events were minimal. LIMITATIONS A randomized controlled trial will be necessary to verify the effects of sildenafil on lymphatic malformations. CONCLUSIONS Sildenafil can reduce lymphatic malformation volume and symptoms in some children.

Safety and Wound Outcomes Following Genetically Corrected Autologous Epidermal Grafts in Patients With Recessive Dystrophic Epidermolysis Bullosa

Importance Recessive dystrophic epidermolysis bullosa (RDEB) is a devastating, often fatal, inherited blistering disorder caused by mutations in the COL7A1 gene encoding type VII collagen. Support and palliation are the only current therapies. Objective To evaluate the safety and wound outcomes following genetically corrected autologous epidermal grafts in patients with RDEB. Design, Setting, and Participants Single-center phase 1 clinical trial conducted in the United States of 4 patients with severe RDEB with a measured area of wounds suitable for grafting of at least 100 cm2. Patients with undetectable type VII collagen keratinocyte expression were excluded. Interventions Autologous keratinocytes isolated from biopsy samples collected from 4 patients with RDEB were transduced with good manufacturing practice-grade retrovirus carrying full-length human COL7A1 and assembled into epidermal sheet grafts. Type VII collagen gene-corrected grafts (approximately 35 cm2) were transplanted onto 6 wounds in each of the patients (n = 24 grafts). Main Outcomes and Measures The primary safety outcomes were recombination competent retrovirus, cancer, and autoimmune reaction. Molecular correction was assessed as type VII collagen expression measured by immunofluorescence and immunoelectron microscopy. Wound healing was assessed using serial photographs taken at 3, 6, and 12 months after grafting. Results The 4 patients (mean age, 23 years [range, 18-32 years]) were all male with an estimated body surface area affected with RDEB of 4% to 30%. All 24 grafts were well tolerated without serious adverse events. Type VII collagen expression at the dermal-epidermal junction was demonstrated on the graft sites by immunofluorescence microscopy in 9 of 10 biopsy samples (90%) at 3 months, in 8 of 12 samples (66%) at 6 months, and in 5 of 12 samples (42%) at 12 months, including correct type VII collagen localization to anchoring fibrils. Wounds with recombinant type VII collagen graft sites displayed 75% or greater healing at 3 months (21 intact graft sites of 24 wound sites; 87%), 6 months (16/24; 67%), and 12 months (12/24; 50%) compared with baseline wound sites. Conclusions and Relevance In this preliminary study of 4 patients with RDEB, there was wound healing in some type VII collagen gene-corrected grafts, but the response was variable among patients and among grafted sites and generally declined over 1 year. Long-term follow-up is necessary for these patients, and controlled trials are needed with a broader range of patients to better understand the potential long-term efficacy of genetically corrected autologous epidermal grafts. Trial Registration clinicaltrials.gov Identifier: NCT01263379.

Treatment decision-making for patients with the Herlitz subtype of junctional epidermolysis bullosa

The Herlitz subtype of junctional epidermolysis bullosa (JEB-H) is a lethal genetic disorder characterized by recurrent and persistent erosions of the epithelial surfaces that heal with exuberant granulation tissue. In addition, respiratory distress, refractory anemia and failure to thrive are often seen. Mortality in the first year of life approaches 90%. JEB-H is caused by mutations in the genes that encode the protein laminin 5, a structural molecule involved in the adhesion of epidermis to dermis. There is currently no cure for JEB-H. Medical interventions treat complications but do not ultimately limit mortality. Ethical principles contend that offering comfort and company to the patient and family, not aggressive therapies, should comprise the mainstay of care for affected infants.

Polyvinylpyrrolidone microneedles enable delivery of intact proteins for diagnostic and therapeutic applications.

We present a method of fabricating microneedles from polyvinylpyrrolidone (PVP) that enables delivery of intact proteins (or peptides) to the dermal layers of the skin. PVP is known to self-assemble into branched hollow fibers in aqueous and alcoholic solutions; we utilized this property to develop dissolvable patches of microneedles. Proteins were dissolved in concentrated PVP solution in both alcohol and water, poured into polydimethylsiloxane templates shaped as microneedles and, upon evaporation of solvent, formed into concentric, fibrous, layered structures. This approach of making PVP microneedles overcomes problems in dosage, uniform delivery and stability of protein formulation as compared to protein-coated metallic microneedles or photopolymerized PVP microneedles. Here we characterize the PVP microneedles and measure the delivery of proteins into skin. We show that our method of fabrication preserves the protein conformation. These microneedles can serve as a broadly useful platform for delivering protein antigens and therapeutic proteins to the skin, for example for allergen skin testing or immunotherapy.