In vitro and in vivo evaluation of nanofibre mats containing Calendula officinalis extract as a wound dressing

Objective: The present study aims to create Calendula officinalis-loaded nanofibre-based wound dressing materials to enhance the wound healing process. Calendula officinalis is an annual herb native to the Mediterranean region. It is antipyretic, antifungal, antioedema, antidiabetic, anti-inflammatory (wound, oral and pharyngeal mucosa), antispasmodic, treats chronic ocular surface diseases, acts as a stimulant and a diaphoretic. It is also used in the prevention of acute dermatitis, and in the treatment of gastrointestinal ulcers, wounds and burns. Method: Electrospinning is an effective method for creating nano-and microfibres for biomedical applications. Calendula officinalis (CA) of various concentrations 5%, 10% and 15%)-loaded polyvinyl alcohol (PVA)/sodium alginate (SAIg) nanofibre mats were successfully produced via blend electrospinning. Nanofibre mats were evaluated using: scanning electron microscopy (SEM); Fourier transform infrared spectroscopy (FTIR) analysis; gel content; water vapour transmission rate (WVTR); swelling ratio; in vitro drug release studies; viability evaluation (cell culture and MIT assay); and an in vivo study using male Wistar rats. Rats were divided into three groups (n=3). In each group, rats were inflicted with five full-thickness wounds on the back and were treated with sterile gauze (control), PVA/SAIg nanofibre dressing (CA-free control), PVA/SAIg/CA5%, PVA/SAIg/CA10%, and PVA/SAIg/CA15% nanofibre dressing. Results: Results showed that the obtained fibres were smooth with no surface aggregates, indicating complete incorporation of Calendula officinalis. The release of Calendula officinalis from loaded PVA/SAIg fibre mats in the first four hours was burst released and then was constant. PVA/SAIg and PVA/SAIg/CA nanofibres were not toxic to L929 mouse fibroblasts and supported cell attachment and proliferation. The results of the in vivo study showed that the PVA/SAIg/CA10% nanofibre dressing had a higher full-thickness wound healing closure rate compared with the control group on days seven, 14 and 21 after treatment. Conclusion: The results of this evaluation showed that PVA/SAIg/CA nanofibrous mats could be a candidate as an effective wound dressing; however, the percentage of CA in this compound needs further investigation.