Agarwood extract loaded poly(vinyl alcohol) (PVA) electrospun fibre as halal biomaterial for wound healing

Abstract

Electrospun nanofibers have been extensively studied for wound healing application due to their remarkable properties. The incorporation of plant extract in electrospun nanofibers has contributed to the development of bioactive dressings enabling the effective and efficient wound repair. In this work, the fabrication of such nanofibers was undertaken following halal built-in concept. Poly (vinyl alcohol) (PVA) fibre mats containing Aquilaria malaccensis leaf extract (ALEX) [5, 10 and 15 %(w/w)] were fabricated by electrospinning for wound healing application. Prior to the fabrication of ALEX-loaded PVA nanofibers, the phytochemical constituents of both derivatized and non-derivatized ALEX were identified using gas chromatography - mass spectrometry (GC-MS). The anti-bacterial activity of ALEX against Escherichia coli, Vibrio vulnificus, Bacillus subtilis and Staphylococcus aureus was evaluated by modified Kirby Bauer disc diffusion method. The anti-inflammatory activity of ALEX was performed via in-vitro lipoxygenase assay. GC-MS analysis of ALEX confirmed the occurrence of a total 127 compounds from the derivatized sample and only 22 compounds in the non-derivatized sample. ALEX showed comparable anti-bacterial activity with zone of inhibition of 10.2 - 21.7 mm for gram positive bacteria and 10.7 - 19.7 mm for gram negative bacteria. Minimum inhibitory concentration (MIC) values of ALEX against these bacteria ranged from 5.625 mg/ml to 0.352 mg/ml. ALEX also showed high lipoxygenase inhibitory activity with an IC50 of 21.365 μg/ml in comparison to the positive control, nordihydroguaiaretic acid (NDGA) with an IC50 of 6.383 μg/ml. These results supported the use of ALEX as an active ingredient in the fibre mats. The nanofibers were uniform, beadless and randomly oriented with average diameters ranged between 195.27 – 281.20 nm. The presence of ALEX in the PVA nanofibers were evaluated by Attenuated total reflectance-Fourier transform infrared microscopy (ATR-FTIR) and differential scanning calorimetry (DSC). Next, the mechanical properties, swelling degree and weight loss of nanofiber mats were also determined. ALEX was rapidly released from the ALEX-loaded PVA nanofibers in the first 12 hours followed by gradual release afterwards. The released rate was dependent on ALEX content in the PVA nanofibers. Swelling degree and porosity of the nanofibers were found to be between 241.66 – 305.86% and 64.53 – 30.81%, respectively. Meanwhile, the tensile stress and maximum elongation at break for all electrospun nanofiber mats were in the range of 8.56 – 2.68 MPa and 205.94 – 166.31%, respectively. The nanofiber mats inhibited growth of Escherichia coli, Vibrio vulnificus, Bacillus subtilis and Staphylococcus aureus with zone of inhibition of 7.5 - 15.0 mm for gram positive bacteria and 6.1 - 11.7 mm for gram negative bacteria. ALEX-loaded PVA nanofibers also showed potent anti-inflammatory activity against lipoxygenase with percentage of inhibition between 80.887 – 86.977%. Taken together, the results of this study suggest that ALEX-loaded PVA nanofibers have the desired properties of bioactive wound dressing and could open up new horizon in the fabrication of wound dressing through its halal built-in concept.