Theses (MSc. Molecular Medicine)

Chronic wounds represent a significant healthcare challenge, often leading to prolonged patient suffering, bacterial infections, and impaired tissue regeneration, causing untreated and long-lasting scars formation. This study explores the potential of curcumin and quercetin-loaded chitosan-pectin scaffolds as a novel solution for enhancing wound healing. Curcumin and quercetin, both are well-known for their antioxidant, anti-inflammatory, and antibacterial properties, were incorporated into chitosan-pectin scaffolds via a lyophilization method. Different ratios of curcumin and quercetin were being explored and tested for their biocompatibility, antioxidant capacity, antibacterial and antibiofilm capacities, drug release profiles as well as physicochemical tests to assess their suitability for wound healing applications. The surface morphology and pore sizes and distributions were assessed with scanning electron microscopy (SEM), and Fourier-transform infrared (FTIR) spectroscopy. Besides that, the antioxidant activity of the resulting scaffolds was tested using 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, while their anti-inflammatory effects were evaluated in vitro through a bovine serum albumin (BSA) denaturation assay. Moreover, the antibacterial efficacy as well as antibiofilm affinity of the scaffolds were tested against Staphylococcus aureus and Pseudomonas aeruginosa. Biocompatibility of the scaffolds was tested via cell viability MTT assay while in-vitro wound healing was assessed using scratch assay. All of the curcumin-quercetin loaded scaffolds demonstrated strong antioxidant activity, ranging from 83 – 90%, and exhibited comparable anti-inflammatory activity, with values between 83 – 91%. They also showed impressive wound healing potential in vitro, with rates ranging from 85 - 100% at the 48-hour. Additionally, the antibiofilm activity against Staphylococcus aureus was notably high, achieving a 75 – 85% biofilm reduction. In comparison, the reduction in biofilm formation for Pseudomonas aeruginosa was moderate, ranging from 45 – 59%. The curcumin-quercetin loaded scaffolds, particularly the scaffold containing curcumin and quercetin at ratio 1:3 demonstrated the most promising results. These findings highlight the potential application of curcumin and quercetin-loaded chitosan-pectin scaffolds in promoting wound healing, addressing bacterial biofilms and supporting tissue regeneration. The results contribute to advancing biomimetic scaffolds as innovative solutions for managing chronic wounds and improving patient outcomes.

Propionibacterium acnes (P. acnes), plays a key role in acne pathogenesis by inducing the innate immune system cells to produce certain pro-inflammatory mediators which contribute to the formation of inflammatory acne lesion. The present study was conducted to evaluate the potential of Doani sidr honey and honey polysaccharide rich fraction and madecassoside for antimicrobial and anti-inflammatory activity against P. acnes. The broth dilution method was used to assess the antibacterial activity and the ultrastructural changes in cell morphology before and after exposure to tested samples were studied using transmission electron microscopy (TEM). The tested samples were further investigated for the suppression of pro-inflammatory cytokines tumour necrosis factor (TNF-α) and interleukin 8 (IL-8) by testing the supernatants in the co-culture of the human peripheral blood mononuclear cells (PBMCs) and heat killed P. acnes using enzyme immunoassay kits (ELISA). The statistical analysis was done using the Graph Pad Prism 5 program. The Doani sidr honey and its polysaccharide rich fraction were able to inhibit the growth of P. acnes with a noteworthy minimum inhibitory concentration (MIC) value of 18%(w/v) and 29 %(w/v) respectively and also the release of TNF-α and IL-8 pro-inflammatory cytokines by suppressing them by more than 90%. TEM micrographs revealed the lethal effects of Doani sidr honey against P. acnes .However, no significant inhibition of the P. acnes growth and the secretion of TNF-α and IL-8 was detected for madecassoside at its highest tested concentration. Our results suggested that Doani sidr honey possess both antimicrobial and anti-inflammatory effects against P. acnes and could possibly be used as therapeutic agents for acne. Furthermore, polysaccharide fraction derived from Doani sidr honey showed potent inhibitory effect toward P. acnes. Hence, we hypothesise the fraction prepared from Doani sidr honey might contribute to honey activity. Therefore, this fraction needs to be further explored and characterised to find the main contributing phytochemicals and the antibacterial and anti-inflammatory properties in this fraction.