Development of PU foam dressings loaded with extract of Plectranthus amboinicus for burn wound healing

Abstract

Objective

To develop Plectranthus amboinicus extract loaded Polyurethane foam dressing for burn wound healing.

Significance

Plectranthus amboinicus is traditionally used as an anti-inflammatory and wound-healing agent. Its incorporation in a PU foam dressing will offer the dual benefits of foam dressing as well as the healing potential of P. amboinicus.

Methods

PU foam dressings were prepared and loaded with P. ambionicus leaf extract (PAE). The dressings were prepared with varying concentrations (0.5–2%) of extract along with Toluene diisocyanate, polypropylene glycol (PPG), and liquid paraffin. The dressings were characterized by Scanning Electron Microscopy and evaluated for Moisture Vapor Transmission Rate, absorption rate, porosity, and mechanical strength followed by in vivo burn wound-healing studies in comparison to a marketed dressing.

Results

The MVTR was found to be optimum in formulations FD2-FD4 with values ranging from 2068.06 ± 0.99 to 2095.00 ± 0.25 g/m²/day. Absorption rate was found to be between 1.27 ± 0.01, 1.31 ± 0.00, and 1.30 ± 0.02 g/cm² for formulations FD2-FD4. Formulations FD1, FD2, FD3, FD4 showed better porosity when compared to other formulations. Formulation FD4 was further characterized by micro-CT and a porosity of 46.32% was obtained. Tensile strength measurement indicated that the selected formulations were flexible enough to withstand regular handling during dressing changes. Acute dermal irritation performed on rabbits showed no irritation, erythema, eschar, and edema. In vivo wound-healing studies performed on albino wistar rats showed that the FD4 formulation has better wound healing property.

Conclusion

Plectranthus ambionicus-loaded PU foam dressing demonstrated promising burn wound-healing potential

GRAPHICAL ABSTRACT

Keywords:

• Plectranthus ambionicus
• polyurethane
• burn wound
• micro-CT
• porosity

The authors extend their gratitude to MSRUAS for providing necessary facilities to support this project. They also acknowledge IISC, Bangalore, SITRA, Coimbatore, IIT Bombay, Poornayu Research labs, Bangalore, IIT Hyderabad and Srinivas Laboratory for their support in carrying out characterization studies.

Authors’ contributions

All authors contributed to the study’s conception and design. The project was conceptualized and initiated by Sindhu Abraham. Akhila, Shwetha, Kesha carried out material preparation, data collection, and analysis. The manuscript was written by Sindhu Abraham, reviewed and edited by Basavaraj. All authors have read and approved the final manuscript.

Ethics approval and consent to participate

The animals were obtained from the in-house animal house facility, Department of Pharmacology, Faculty of Pharmacy, and the protocol was approved by the Institutional Animal Ethical Committee (IAEC), vide reference number XXVII/MSRFPH/CEU/PG-18/13.02.2023.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Availability of data and material

All data generated during this study are available as a part of this article and no additional source data are required.

Additional information

Funding

This research has not received external funding.