Multifunctional Bacterial Cellulose Films Incorporating Kratom (Mitragyna speciosa Korth.) Leaf Extract as a...

Leaves of Mitragyna speciosa Korth. (M. speciosa), commonly known as Kratom, are rich in alkaloids, with mitragynine as the main bioactive compound. This study presents a technique for the entrapment of ethanolic Kratom leaf extract within bacterial cellulose (BC) films and the subsequent controlled release of mitragynine. Kratom leaves were dried, ground, and extracted by maceration in 95% ethanol at 35 °C for 72 h. The extract was incorporated into the BC matrix via the immersion method, followed by air-drying at room temperature (~32 °C). BC's highly porous structure facilitates sustained mitragynine absorption and entrapment within a tight nanofibrillar network. The mitragynine content in the BC films ranged from 9.1 to 23.3 mg/g, allowing for the evaluation of its effects on film properties and drug release performance. Release studies were conducted using Franz diffusion cells, with acetate buffer (pH 5.5) and phosphate buffer (pH 7.4) as receptor phases. Consistent with its higher solubility in acidic conditions, mitragynine showed greater release in acetate buffer, particularly within the first 0-12 h. The release profile depended on both mitragynine loading and time. The mitragynine-loaded BC films exhibited strong antimicrobial activity, achieving 100% reduction of Staphylococcus aureus and Escherichia coli. In vitro studies using L929 mouse fibroblast cells demonstrated that the films were noncytotoxic. The films also promoted proliferation and viability of normal human epidermal keratinocytes. Overall, the mitragynine-loaded BC films support skin cell growth and attachment and exhibit antibacterial, antioxidant, and anti-inflammatory properties, highlighting their potential as candidates for wound healing applications.