From Plants to Wound Dressing and Transdermal Delivery of Bioactive Compounds

Abstract

Transdermal delivery devices and wound dressing materials are constantly improved and upgraded with the aim of enhancing their beneficial effects, biocompatibility, biodegradability, and cost effectiveness. Therefore, researchers in the field have shown an increasing interest in using natural compounds as constituents for such systems. Plants, as an important source of so-called "natural products" with an enormous variety and structural diversity that still exceeds the capacity of present-day sciences to define or even discover them, have been part of medicine since ancient times. However, their benefits are just at the beginning of being fully exploited in modern dermal and transdermal delivery systems. Thus, plant-based primary compounds, with or without biological activity, contained in gums and mucilages, traditionally used as gelling and texturing agents in the food industry, are now being explored as valuable and cost-effective natural components in the biomedical field. Their biodegradability, biocompatibility, and non-toxicity compensate for local availability and compositional variations. Also, secondary metabolites, classified based on their chemical structure, are being intensively investigated for their wide pharmacological and toxicological effects. Their impact on medicine is highlighted in detail through the most recent reported studies. Innovative isolation and purification techniques, new drug delivery devices and systems, and advanced evaluation procedures are presented.

Keywords: antimicrobial; bioactive molecule; biomaterials; cell wall components; metabolites; transdermal delivery; wound dressing.

Figure 1

Five main methods to enhance API absorption across the skin: drug–vehicle interaction, vesicles, and analogues; SC modification; energy-driven methods; and SC bypass [16]. (Pink color indicates the first generation of SC penetration devices; Yellow—the second generation of SC penetration devices/methods; Blue—the third generation of SC penetration devices/methods).

Figure 2

Evolution of patches: (a1) ointment on a bandage system representation from ancient times; (a2) plaster (here, mustard and belladonna for controlled drug delivery, medical device developed prior to 1900s); (a3) delivery device (here, first recognized topical delivery system); (b) different types of patches; (c) different types of microneedles (minimally invasive patches). Adapted with permission [22,23]. (The arrows represent the application/removal method of the microneedle device).