Novel tissue engineering scaffolds as wound dressings loaded with Alkannins/Shikonins as active ingredients

Alkannin and Shikonin (A/S) are bioactive natural products biosynthesized in the roots of some Boraginaceous plants. They have been primarily well-known for their strong wound healing and regenerative activities [1]. A/S comprise the active ingredients of approved -by the National Organization for Medicines- wound healing pharmaceutical preparations (HELIXDERM®, Histoplastin Red®) invented by Prof. Papageorgiou.

This work is a continuation of our previous studies [2] on fabricating electrospun scaffolds impregnated with a mixture of A/S pigments. Specifically, several biodegradable polymers were used [cellulose acetate (CA), poly(l-lactide) (PLLA), polycaprolactone (PCL) and polycaprolactone/polyethylene glycol (PCL/PEG)] and scaffolds were assessed for the first time for their biocompatibility upon cell seeding.

A/S-loaded and non-loaded scaffolds were produced as previously reported [2]. The scaffolds were cut in 8 mm discs, seeded with human foreskin fibroblast cells (Hs27) and cultured for up to 7 days. Several physicochemical and biological characteristics were evaluated: drug content, in vitro drug release profile, scaffolds morphology by SEM, cell viability at different time points by MTT assay and cell infiltration by confocal microscopy.

All A/S-loaded scaffolds displayed a favorable matrix to cell attachment. After 7 days of culturing, the fiber mats demonstrated adequate cell viability with PCL-A/S and PEGylated PCL-A/S showing increased proliferation compared to non-loaded PCL and PCL/PEG scaffolds.

This study was the first attempt to shed light on the biological potential of Alkannins/Shikonins combined with electrospun polymeric scaffolds to serve as medical devices for repairing and regenerating damaged skin tissue.

Fig. 1

• References

• 1 Papageorgiou VP, Assimopoulou AN, Couladouros EA, Hepworth D, Nicolaou KC. The chemistry and biology of alkannin, shikonin, and related naphthazarin natural products. Angew Chemie - Int Ed 1999; 38: 270-300
• 2 Kontogiannopoulos KN, Assimopoulou AN, Tsivintzelis I, Panayiotou C, Papageorgiou VP. Electrospun fiber mats containing shikonin and derivatives with potential biomedical applications. Int J Pharm 2011; 409: 216-228