A β-cyclodextrin, polyethyleneimine and silk fibroin hydrogel containing Centella asiatica extract and hydrocortisone acetate: releasing properties and in vivo efficacy for healing of pressure sores.

Abstract

BACKGROUND:

  Pressure sores are lesions caused by impaired blood flow. Conventional dressings can absorb exudates, but do not promote wound healing. A hydrogel composed of β-cyclodextrin (β-CD), polyethyleneimine (PEI) and silk fibroin (SF) was assessed for use in healing of pressure sores.

METHODS:

The hydrogel was prepared by crosslinking β-CD-grafted PEI and SF using epichlorohydrin. The gel was then immersed in an aqueous solution of Centella asiatica extract (CAE) 0.7 mg/mL and/or hydrocortisone acetate (HCA) 0.5 mg/mL. The in vivo pressure sore-healing efficacy of the dry gel (with or without the drugs) was investigated in terms of the hyperplasia of epidermis and the number of neutrophils in the skin tissue.

RESULTS:

The specific loading of CAE was 0.0091 g/g of dry gel. The percentage of CAE released at 24 h at pH 3.0, 5.0 and 7.4 was approximately 63.9%, 55.0% and 44.4%, respectively. This pH-dependent release is possibly due to the degree of gel swelling, which decreased with increasing pH. The specific loading of HCA was 0.0050 g/g dry gel, and the percentage release of HCA at 24 h was around 20% at all three pH points. It is likely that HCA release is independent of pH. HCA is a hydrophobic compound, and therefore the release of HCA is affected by the partitioning of HCA between the β-CD cavity and the bulk water phase, but not by the degree of swelling of the hydrogel. The pressure sores treated with the hydrogel healed in 6 days, compared with 10 days for controls.

CONCLUSIONS:

In this study, a β-CD/PEI/SF hydrogel containing CAE and HCA reduced the healing time for pressure sores.

• Authors: M S Lee, S R Seo, J-C Kim
• Journal: Clinical and experimental dermatology (Clin Exp Dermatol) Vol. 37 Issue 7 Pg. 762-71 (Oct 2012) ISSN: 1365-2230 [Electronic] England
• PMID: 22439751 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: © The Author(s). CED © 2012 British Association of Dermatologists.

Chemical References

• Centella asiatica extract
• Hydrogels
• Plant Extracts
• Silk
• Triterpenes
• beta-Cyclodextrins
• hydrocortisone acetate
• Polyethyleneimine
• Fibroins
• Hydrocortisone

Topics

• Animals
• Centella
• Fibroins (therapeutic use)
• Hydrocortisone (analogs & derivatives, therapeutic use)
• Hydrogels (chemical synthesis, therapeutic use)
• Male
• Mice
• Mice, Inbred ICR
• Plant Extracts
• Polyethyleneimine (therapeutic use)
• Pressure Ulcer (drug therapy)
• Silk
• Skin (drug effects)
• Triterpenes (therapeutic use)
• Wound Healing (drug effects)
• beta-Cyclodextrins (therapeutic use)