Formulation of survival acceptor medium able to maintain the viability of skin explants over
            in vitro
            dermal experiments

Several reports have suggested that mesenchymal glycosaminoglycans (GAG) may be involved in the regulatory role of epithelial differentiation. Some researchers have pointed out that exogenousGAG affects extracellular GAG accumulation. We have therefore examined the effect of added GAG on two typical processes of avian skin differentiation: keratinization and feather formation. Glycosaminoglycans, either obtained from fibroblasts cultures (conditioned media) or purified commercially available GAG were administered to 5/6-day chick embryo back skin explants. Control cultures were supported with 199 synthetic medium, chick embryo extract or calf serum. Explants have been examined by histological and histochemical procedures. Skin explants maintained in vitro for 7 days exhibited an epithelial differentiation and a dermal histochemical reactivity which were related to the composition of the culture medium. In conditioned media from dermal fibroblasts, but not from heart or lung fibroblasts, explants always exhibited keratinization. In purified-GAG-containing media, keratinization was observed with condroitinsulphates and not with hyaluronic acid. Keratinization was always related toprevalent accumulation of hyaluronic acid in the underlying mesenchyme whereas feather formation was in relation to deposits of condroitinsulphates in dermis pulp. The above findings demonstrate that exogenous GAG is able to modulate avian skin differentiation and that this regulation is linked to an influence on the mesenchymal GAG pattern.

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Assessment of the biochemical effects of percutaneous exposure of sulphur mustard in an in vitro human skin system

Human & Experimental Toxicology ◽

10.1177/096032719601500309 ◽

1996 ◽

Vol 15 (3) ◽

pp. 237-244 ◽

Cited By ~ 24

Author(s):

CD Lindsay ◽

P. Rice

Keyword(s):

Inflammatory Response ◽

Human Skin ◽

Serine Proteases ◽

Inflammatory Cells ◽

Chemical Warfare Agent ◽

Skin Damage ◽

Sulphur Mustard ◽

Nuclear Pyknosis ◽

Skin Explants

1 Sulphur mustard (HD) is a potent chemical warfare agent which causes incapacitating blisters on human skin. There is no specific pretreatment nor therapy against this agent and the mechanism of dermo-epidermal cleavage is unclear. The aim of this study was to use a human skin explant system to determine the consequences of percuta neous exposure to HD. 2 Increased activities of serine proteases associated with blistering disorders in humans were detected from human skin explants after exposure to HD. The most consistent response and the highest protease activities measured were found for trypsin. This class of enzyme is therefore implicated in the dermo-epidermal separation which is associated with blistering in humans following exposure to HD. 3 An inflammatory response was observed in the skin explants exposed to HD. At low doses of HD it was characterised by the presence of neutrophils in the papillary dermis, culminating in the infiltration of the epidermis by these inflammatory cells at higher concen trations of HD. A variety of other histopathological changes in the explants was found such as focal dermo- epidermal separation, nuclear pyknosis and perinuclear vacuolation. 4 The study indicates that full thickness human skin explants can be used to investigate various aspects of the possible pathogenesis of HD-induced skin damage, in cluding the associated inflammatory response.

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Chronic Wounds, Biofilms and Use of Medicinal Larvae

Ulcers ◽

10.1155/2013/487024 ◽

2013 ◽

Vol 2013 ◽

pp. 1-7 ◽

Cited By ~ 9

Author(s):

Linda J. Cowan ◽

Joyce K. Stechmiller ◽

Priscilla Phillips ◽

Qingping Yang ◽

Gregory Schultz

Keyword(s):

Chronic Wounds ◽

Wound Care ◽

The United States ◽

Bacterial Biofilms ◽

Host Defenses ◽

Skin Explants ◽

Healing Wounds ◽

Phaenicia Sericata ◽

Significant Health

Chronic wounds are a significant health problem in the United States, with annual associated costs exceeding $20 billion annually. Traditional wound care consists of surgical debridement, manual irrigation, moisture retentive dressings, and topical and/or systemic antimicrobial therapy. However, despite progress in the science of wound healing, the prevalence and incidence of chronic wounds and their complications are escalating. The presence & complexity of bacterial biofilms in chronic wounds has recently been recognized as a key aspect of non-healing wounds. Bacterial biofilms are sessile colonies of polymicrobial organisms (bacteria, fungus, etc.) enclosed within a self-produced exopolymeric matrix that provides high levels of tolerance to host defenses, antibiotics and antiseptics. Thus, there is a need for alternative therapies to reduce biofilms in chronic wounds. In this report, we present initial findings from in vitro experiments which show that larval debridement therapy with disinfected blow fly larvae (Phaenicia sericata) reduced total CFUs (6-logs) of planktonic and mature biofilms of Pseudomonas aeruginosa or Staphylococcus aureus grown on dermal pig skin explants by 5-logs after 24 hours of exposure, and eliminated biofilms (no measurable CFUs) after 48 hours of exposure.

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Novel Rotational Combination Regimen of Skin Topicals Improves Facial Photoaging: Efficacy Demonstrated in Double-Blinded Clinical Trials and Laboratory Validation

Frontiers in Medicine ◽

10.3389/fmed.2021.724344 ◽

2021 ◽

Vol 8 ◽

Author(s):

Lisa DiNatale ◽

Jolanta Idkowiak-Baldys ◽

Young Zhuang ◽

Anthony Gonzalez ◽

Thomas J. Stephens ◽

...

Keyword(s):

Clinical Trials ◽

Ex Vivo ◽

Dermal Fibroblasts ◽

Combination Regimen ◽

Crow’S Feet ◽

Skin Explants ◽

Study Methodology ◽

Double Blinded

Topical antiaging products are often a first-line intervention to counter visible signs of facial photoaging, aiming for sustained cosmetic improvement. However, prolonged application of a single active topical compound was observed clinically to lead to a plateau effect in improving facial photoaging. In view of this, we set out to reduce this effect systematically using a multi-tiered approach with laboratory evidence and clinical trials. The objective of the study was to evaluate the effects of active topical ingredients applied either alone, in combination, or in a rotational manner on modulation of facial photoaging. The study methodology included in vitro, organotypic, and ex vivo skin explants; in vivo biopsy study; as well as clinical trials. We demonstrate for the first time that a pair of known antiaging ingredients applied rotationally, on human dermal fibroblasts, maximized pro-collagen I production. Indeed, rotational treatment with retinol and phytol/glycolic acid (PGA) resulted in better efficacy than application of each active ingredient alone as shown by explants and in vivo biopsy study, with penetration of active ingredients confirmed by Raman spectroscopy. Furthermore, two split-face, randomized, double-blinded clinical trials were conducted, one for 12 months to compare treated vs. untreated and the other for 6 months followed by a 2-month regression to compare treated vs. commercially marketed products. In both studies, rotational regimen showed superior results to its matching comparison as assessed by clinical grading and image analysis of crow's feet wrinkles. In conclusion, rotational regimen using retinol and PGA is effective in treating facial photoaging signs with long-lasting benefits.

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