UV-curable pressure sensitive adhesive films: effects of biocompatible plasticizers on mechanical and adhesion properties

Abstract

We developed a new approach to fabricate pressure sensitive adhesive (PSA) hydrogel films for dermatological applications. These hydrogel films were fabricated using polyvinylpyrrolidone (PVP), poly(ethylene glycol) diacrylate (PEGDA) and polyethylene glycol (PEG) with/without propylene glycol (PG) via photo-polymerization. Hydrogel films with a thickness ranging from 130 to 1190 mm were obtained. The surface morphology and drug distribution within the films were found to be uniform.The effects of different factors (polymeric composition, i.e., PEG/PG presence and film thickness) on the functional properties (i.e., rheological and mechanical properties, adhesion performance and drug distribution) of the films were investigated. The addition of plasticizers, namely PEG and PG, resulted in a simultaneous increase in elasticity and adhesiveness of these hydrogels, via the formation of hydrogen bonds, which has a direct correlation with their adhesion properties. The new approach is potentially useful for industrial applications, due to the simple procedure, precise control over film thickness, minimal usage of solvents and adjustable mechanical, rheological and adhesive properties.engineering. 4,13 The requirements of medical PSAs are challenging as they must be able to exhibit appropriate gel strength and sufficient adhesiveness against varying skin types and at the same time, 14 they should be easily removable from the skin surface without excessive irritation to the skin and leaving no residues on the skin. Hydrogel polymers have been used to produce medical PSAs. 4 The major chemical systems used for medical PSAs are acrylate based hydrogels, due to their suitable adhesive properties and a low level of skin irritation. Other polymer types, used as PSAs, include silicone-based adhesives, polyvinyl ether-based adhesives and polyvinylpyrrolidone-based adhesives. 4,15 In general, conventional hydrogels used as adhesives for medical applications are developed by chemical or physical crosslinkings.Solvent-free pressure sensitive adhesives, i.e., hot-melt PSAs (HMPSAs) and radiation curable PSAs, are a relatively new group of self-adhesive medical products and are of increasing importance due to environmental pressure on solvent-borne PSAs and the performance shortcomings of aqueous systems. 4,15 Both HMPSAs and radiation curable PSAs have grown lately due to reduced solvent consumption and waste emissions. These environmentally friendly adhesives are made from reactive compounds that contain almost no solvents (or negligible amount) or other volatile substances. In addition, photo-polymerization enables rapid conversion of monomer or macromer precursor solutions into a gel or solid under physiological conditions potentially useful for medical applications. 16 Photopolymerization is simply initiated by irradiation with light, such

Silicone-based adhesives for long-term skin application: cleaning protocols and their effect on peel strength

“…The anatomy, topical features such as texture and roughness (R a values, the arithmetical mean value of the amounts of the ordinate value within an individual measuring distance, for both human and pig skin are 20±3 μm [24]), and the biochemical property of pig skin are remarkably similar to those of human skin [21]. Therefore, hair-removed pig skins have become increasingly utilized as a substrate material to mimic human skin for topical adhesion studies [25,26].…”

Development and Characterization of Pressure-Sensitive Adhesives from Dimer Acid and Epoxides

“…In addition, the PSAs contained hydroxyl groups (-OH) and a small amount of unreacted -COOH groups. The -OH and -COOH groups could improve the wetting of the PSAs on various adherends such as paper, glass, and skin, thus facilitating the intimate contact between the PSAs and the adherends (11,(23)(24)(25). These functional groups in PSAs could also significantly improve the adhesive strength of the PSAs through formations of hydrogen bonds between the PSAs and adherends (23)(24)(25)(26).…”

“…These functional groups in PSAs could also significantly improve the adhesive strength of the PSAs through formations of hydrogen bonds between the PSAs and adherends (23)(24)(25)(26). The -OH and -COOH groups also allowed formations of hydrogen bonds among molecular chains and within the same molecular chain of the PSA, thus increasing the cohesive strength of the PSA (11,(23)(24)(25)(26).…”

“…The -OH and -COOH groups could improve the wetting of the PSAs on various adherends such as paper, glass, and skin, thus facilitating the intimate contact between the PSAs and the adherends (11,(23)(24)(25). These functional groups in PSAs could also significantly improve the adhesive strength of the PSAs through formations of hydrogen bonds between the PSAs and adherends (23)(24)(25)(26). The -OH and -COOH groups also allowed formations of hydrogen bonds among molecular chains and within the same molecular chain of the PSA, thus increasing the cohesive strength of the PSA (11,(23)(24)(25)(26).…”

Addressing Unmet Clinical Needs with UV Bioadhesives

“…47 DOPA residue is found on the adhesive protein secreted by marine mussels for underwater adhesion and has been used as an instant mucoadhesive. 53 Similarly, synthetic polymers such as poly(glycerol sebacate) (PGS), 54 poly(vinyl acetate) (PVA), 55,56 PEG, 57,58 and poly(εcaprolactone) (PCL) 59−61 have been acrylated for subsequent UV activation using either Irgacure 2959 or Darocur 2959 as a photoinitiator. A prepolymer of PGS acrylated with acryloyl chloride (poly(glycerol sebacate acrylate); PGSA) was crosslinked using 320−390 nm light (UVA) with a dose of 1.9 J cm −2 in 5 s. 54 The mechanical properties of PGSA are comparable to those of human soft tissue, 62−64 and the adhesive was found to entangle with native collagen fibers.…”