Self-Adhesive and Antioxidant Poly(vinylpyrrolidone)/Alginate-Based Bilayer Films Loaded with Malva sylvestris Extracts as Potential Skin Dressings

Abstract

Malva sylvestris (MS) is a medicinal herb known worldwide for its beneficial effects due to the several active molecules present in its leaves and flowers. These compounds have shown antioxidant and anti-inflammatory properties and thus can be helpful in treatments of burns and chronic wounds, characterized mainly by high levels of free radicals and impairments of the inflammatory response. In this work, we propose bilayer films as wound dressings, based on poly(vinylpyrrolidone) (PVP) and sodium alginate loaded with M. sylvestris extracts from leaves and flowers and fabricated by combining solvent-casting and rod-coating methods. The top layer is produced in two different PVP/alginate ratios and loaded with the MS flowers’ extract, while the bottom layer is composed of PVP and MS leaves’ extract. The bilayers were characterized morphologically, chemically, and mechanically, while they showed superior self-adhesive properties on human skin compared to a commercial skin patch. The materials showed antioxidant activity, release of the bioactive compounds, and water uptake property. Moreover, the anthocyanin content of the flower extract provided the films with the ability to change color when immersed in buffers of different pH levels. In vitro tests using primary keratinocytes demonstrated the biocompatibility of the MS bilayer materials and their capacity to enhance the proliferation of the cells in a wound scratch model. Finally, the best performing MS bilayer sample with a PVP/alginate ratio of 70:30 was evaluated in mice models, showing suitable resorption properties and the capacity to reduce the level of inflammatory mediators in UVB-induced burns when applied to an open wound. These outcomes suggest that the fabricated bilayer films loaded with M. sylvestris extracts are promising formulations as active and multifunctional dressings for treating skin disorders.

Biomedical materials for wound dressing: recent advances and applications

“… 91 In addition, alginate is also combined with many naturally derived extractions such as Malva sylvestris 92 or oregano essential oil, 93 which shows antimicrobial, 93 anti-inflammatory and high biocompatibility properties. 92 …”

“…91 This bioactive dressing not only improved wound closure, collagen synthesis, and vessel formation but also was biodegradable and biocompatible. 91 In addition, alginate is also combined with many naturally derived extractions such as Malva sylvestris 92 or oregano essential oil, 93 which shows antimicrobial, 93 anti-inammatory and high biocompatibility properties. 92 Clinically, alginate dressing had been shown to be effective in healing processes, causing less pain during dressing changes for patients.…”

“…91 In addition, alginate is also combined with many naturally derived extractions such as Malva sylvestris 92 or oregano essential oil, 93 which shows antimicrobial, 93 anti-inammatory and high biocompatibility properties. 92 Clinically, alginate dressing had been shown to be effective in healing processes, causing less pain during dressing changes for patients. 11,94 Another randomized study evaluated the clinical therapeutic effect of human granulocyte-macrophage colony-stimulating factor incorporated with alginate dressings in the treatment of refractory chronic skin ulcers.…”

Development of a cost-effective and sustainable nanoplatform based on a green gold sononanoparticles/carbon black nanocomposite for high-performance simultaneous determination of nanoplastics

“…42 Furthermore, by considering the medicinal (mainly antioxidant and anti-inflammatory) properties of Malva sylvestris , it is expected that metal nanoparticles synthesized with Malva leaf extracts might be biocompatible as well. 43 The so-obtained AuSNPs were used together with CB to build CB/AuSNPs nanocomposite modified SNGCEs by a simple drop-casting process. The CB/AuSNPs/SNGCE displayed high sensitivity and good selectivity for the simultaneous detection of HQ, CC and RC.…”

Colorimetric Indicators Based on Anthocyanin Polymer Composites: A Review

“…As a result, scientists recently focused on the use of natural and biocompatible pH sensitive dyes, such as curcumin [ 23 ], alizarin [ 24 , 25 , 26 ], litmus [ 27 ], naphthoquinone [ 28 , 29 ], Spirulina sp. [ 30 ], or anthocyanins [ 31 , 32 , 33 ], with the latter to be the most popular for such applications.…”