The doctoral dissertation of Elias Haapakorva, MSc, in the field of Biomedicine will be examined at the Faculty of Health Sciences at Kuopio Campus on 8 May, 2026.
What is the topic of your doctoral research? Why is it important to study the topic?
Interest in plant-based wound treatments has grown due to traditional method limitations, antimicrobial resistance, and the need for safer options. Coniferous resin from Norway spruce (Picea abies) has been used in Northern European folk medicine for treating skin wounds and infections for centuries. Recent studies have validated these applications, with clinical trials showing refined spruce resin products effectively treat complex wounds and demonstrate antimicrobial properties against antibiotic resistant bacteria.
The primary objective of this dissertation was to deepen the understanding of the medicinal uses of coniferous resin and to clarify the biological characteristics and pharmaceutical potential of its extracts. We created an innovative oil-in-water dispersion of oxidised resin to enable research in aqueous in vitro environments.
What are the key findings or observations of your doctoral research?
Novel aqueous oil-in-water emulsions containing extracts from natural coniferous resins demonstrated strong antimicrobial properties against bacteria and yeasts. These emulsions were effective against Gram-positive and Gram-negative bacteria, including antibiotic-resistant strains like MRSA. The primary antimicrobial agents were identified as oxidised resin acids. Other resin components, like lignans and coumaric acids, showed no significant antimicrobial activity when tested individually. The emulsions inhibited biofilm formation and eradicated existing microbial biofilms. The antimicrobial action shows a stoichiometric relationship between resin acid molecules and microbial cells. The oxidised resin acids appear extremely potent natural antimicrobial compounds, effective at much lower concentrations than traditional resin salves. Aqueous dispersions of spruce resin (RE) and purified pinoresinol (PINO) suppress TNF-α and IL-1β expression in peripheral blood mononuclear cells and promotes keratinocyte proliferation in studies with aqueous resin extracts. The study suggests lignans like PINO could benefit chronic skin ulcers by encouraging keratinocyte proliferation and modulating inflammatory responses. PINO's ability to reduce inflammation while promoting keratinocyte proliferation may offer a novel therapeutic approach for chronic wound treatment.
How can the results of your doctoral research be utilised in practice?
This study provides new insights into the effects of resin and its extractives on wound healing mechanisms. It is well established that the resin acids contained in resin exhibit significant antimicrobial activity against a wide range of gram-negative and gram-positive bacteria, yeasts, and molds, thereby promoting wound healing by inhibiting the growth of harmful bacterial flora in the wound area. Microbial infections are particularly common in chronic wounds and post-surgical leg ulcers. This study demonstrates that lignans found in resin, such as pinoresinol, may promote wound healing by reducing the inflammatory response and enhancing the proliferation of keratinocytes in the wound area. The absence of abietic acid, the primary allergenic compound in resins, in these solutions suggests that they may serve as suitable and well-tolerated antimicrobials for various medical applications. These new aqueous resin dispersions are well tolerated and exhibit very low allergenic potential.
What are the key research methods and materials used in your doctoral research?
In this study, a novel oil-in-water dispersion of oxidised resin acids was developed, and the extractives it contained, as well as their concentrations, were identified. These extractives were examined collectively and individually in vitro to ascertain the antimicrobial and molecular biological properties of each extract. Additionally, the healing rate of leg ulcers was investigated in patients with critical limb ischemia (CLI) who had undergone peripheral arterial revascularization surgery using either resin or honey ointment. Furthermore, the allergenic potential of the resin-in-water dispersion was evaluated using a standardised patch test.
The doctoral dissertation of Elias Haapakorva, MSc, entitled Coniferous resin and its extracts in wound healing: from folk tradition to modern medicine will be examined at the Faculty of Health Sciences. The Opponent in the public examination will be Professor Varpu Marjomäki of the University of Jyväskylä, and the Custos will Professor Emeritus Atte von Wright of the University of Eastern Finland. The public examination will be held in Finnish.
For further information, please contact:
Elias Haapakorva, MSc, [email protected]
