Cyanoacrylate glues are a renowned synthetic tissue sealant that cures rapidly through polymerization at room temperature, felicitating medical glues to treat skin wounds and surgical openings. Despite a wide range of cyanoacrylates available, only 2-octyl cyanoacrylates (OCA) provides the best biocompatibility. In this study, the polymerization and adhesive properties of 2-octyl cyanoacrylates (OCA) are explored in the presence of a highly biocompatible and biochemically inert polymer, poly(ethylene glycol) polyhedral oligomeric silsesquioxane (PEG-POSS). The effect of PEG-POSS on the polymerization of OCA is examined on a plastic surface and over pig skin. A peel-test is performed to evaluate the strength of OCA adhesive properties between two pieces of pig skin samples. Additionally, thin films of OCA are prepared using different fillers and evaluated for tear test. The results reveal that when applied on the plastic or pig skin, PEG-POSS initiated polymerization in OCA yields a high molecular weight OCA polymer with much better adhesive properties compared to commercially available cyanoacrylate adhesives. The relative change in the molecular weights of OCA compared to commercially available cyanoacrylate bioadhesives such as Dermaflex is much higher. The pig skin peeling test shows that OCA needs higher peeling force than Dermaflex.

Studies suggest that moisturisers have a beneficial effect on psoriasis, and their use in preventive or adjuvant dermatological therapy is therefore of considerable clinical interest, although no classification of these products exists to guide their use. We have previously suggested a classification based on the ability of moisturisers to induce mechanical changes in normal skin. In psoriasis patients obvious objective differences exist between plaques and clinically uninvolved skin. This study was undertaken to investigate if these differences influence the mechanical response to moisturisers. Skin mechanics distension and hysteresis, Dermaflex as well as capacitance Corneometer 812 CM and moisturiser absorption were measured on psoriasis plaques and adjacent clinically uninvolved skin of 17 psoriasis patients. Three commonly available moisturisers, a barrier cream and a gel were tested. Baseline distensibility and capacitance were significantly lower for plaques (p < 0.0001), and all moisturisers increased distensibility in both lesions and adjacent skin. Hysteresis was generally affected to a greater degree by Locobase. The gel caused greater increases in hysteresis outside plaques. Capacitance was significantly increased in plaques, except for areas treated with Locobase, while only Decubal appeared to cause significant increases in uninvolved skin. Locobase showed better absorption in plaques than in control areas. No objective differences were found in the effects of moisturisers between psoriatic plaques and adjacent clinically uninvolved skin, suggesting that the significant clinical differences between lesional and paralesional skin do not influence the efficacy of moisturisers.

Application of water and glycerin is known to influence skin mechanics. The kinetics of these processes are of great interest. A study was performed to show the immediate changes in skin-mechanics. A Dermaflex machine (R) was used to study 23 healthy volunteers. Water or glycerin was applied to the flexorside of the forearm, and readings were made after 3, 6, 9, 12 and 15 min. Regional untreated skin served as baseline. In agreement with earlier studies both substances influenced hysteresis. Water caused a significant increase in hysteresis after 12 and 15 min of hydration (P<0.01). Glycerin caused significantly increased hysteresis after 3 min (P<0.05) and the effect continued to the end of the observation period. No significant differences were seen in the distensibility. The onset of action is rapid for both substances, and the effects are therefore supposed to take place in the outermost layers of epidermis. The effect of glycerin on the hysteresis is more rapid in onset than that of water. Comparing the permeability coefficients, the effect on the mechanical properties of the skin does not appear to be determined by the permeability coefficients as water has a higher permeability coefficient but induces smaller changes than glycerin. Water alone does not appear to be the optimal plasticiser of human skin and other substances soluble in both water and lipids may have an even greater influence on skin mechanics in vivo.