RESUMO
The wound-healing capacity of ointments based on bee products was investigated in vivo on three experimental models of incision, excision and heat burn. For this purpose, four ointments were prepared with propolis, honey, apilarnil (drone brood homogenate) and a mixture of these three apitherapy products. The ointments were applied topically for 21 days. Clinical and macroscopic evaluation was performed throughout the experiment, with the recording of the re-epithelialization period and determination of the wound contraction rate on days 6 and 9. The histopathological examination was performed on days 1, 3, 12 and 21 of the treatment. The topical formulations were also characterized from a rheological point of view in order to verify their stability. HPLC analysis of propolis revealed the presence of phenolic compounds, particularly ferulic acid and p-coumaric which were found in high amounts. All ointments had beneficial effects on wound contraction and the re-epithelialization period, but the most significant result, both macroscopically and especially in terms of histological architecture, was presented by the ointment that contains all three apitherapy products, due to their synergistic effect.
RESUMO
Chitosan-based nanofibers (CS-NFs) are excellent artificial extracellular matrices (ECMs) due to the resemblance of CS with the glycosaminoglycans of the natural ECMs. Despite this excellent feature, the poor electrospinnability and mechanical properties of CS are responsible for important limitations in respect to its biomedical applications. To improve the CS's physico-chemical properties, new bioactive and biomimetic CS-NFs were formulated with polyethylene oxide (PEO), having incorporated different active components (ACs) with important beneficial effects for healing. Manuka honey (trophic and antimicrobial effects), propolis (antimicrobial effects), Calendula officinalis infusion (antioxidant effect, reepithelialization stimulating agent), insulin (trophic effect), and L-arginine (angiogenic effect) were selected as ACs. SEM morphology analysis revealed well-alignment, unidirectional arrays, with small diameters, no beads, and smooth surfaces for developed CS_PEO-ACs NFs. The developed NFs showed good biodegradability (NFs mats lost up to 60% of their initial weight in PBS), increased hemocompatibility (hemolytic index less than 4%), and a reduced cytotoxicity degree (cell viability degree more than 90%). In addition, significant antioxidant and antimicrobial effects were noted for the developed NFs which make them suitable for chronic wounds, due to the role of oxidative stress and infection risk in delaying normal wound healing. The most suitable for wound healing applications seems to be CS_PEO@P_C which showed an improved hemolysis index (2.92 ± 0.16%), is non-toxic (cell viability degree more than 97%), and has also significant radical scavenging effect (DPPH inhibition more than 65%). In addition, CS_PEO@P_C presents increased antimicrobial effects, more noticeably for Staphylococcus aureus strain, which is a key feature in preventing wound infection and delaying the healing process. It can be concluded that the developed CS/PEO-ACs NFs are very promising biomaterials for wound care, especially CS_PEO@P_C.