Bigel Formulations of Nanoencapsulated St. John’s Wort Extract—An Approach for Enhanced Wound Healing

Abstract

This study aimed to develop a semisolid vehicle for topical delivery of nanoencapsulated St. John’s wort (SJW) extract, rich in hyperforin (HP), and explore its wound-healing potential. Four nanostructured lipid carriers (NLCs) were obtained: blank and HP-rich SJW extract-loaded (HP-NLC). They comprised glyceryl behenate (GB) as a solid lipid, almond oil (AO), or borage oil (BO) representing the liquid lipid, along with polyoxyethylene (20) sorbitan monooleate (PSMO) and sorbitan monooleate (SMO) as surfactants. The dispersions demonstrated anisometric nanoscale particles with acceptable size distribution and disrupted crystalline structure, providing entrapment capacity higher than 70%. The carrier exhibiting preferable characteristics (HP-NLC2) was gelled with Poloxamer 407 (PM407) to serve as the hydrophilic phase of a bigel, to which the combination of BO and sorbitan monostearate (SMS) organogel was added. The eight prepared bigels with different proportions (blank and nanodispersion-loaded) were characterized rheologically and texturally to investigate the impact of the hydrogel-to-oleogel ratio. The therapeutic potential of the superior formulation (HP-NLC-BG2) was evaluated in vivo on Wistar male rats through the tensile strength test on a primary-closed incised wound. Compared with a commercial herbal semisolid and a control group, the highest tear resistance (7.764 ± 0.13 N) was achieved by HP-NLC-BG2, proving its outstanding wound-healing effect.

Tissue Regeneration and Remodeling in Rat Models after Application of Hypericum perforatum L. Extract-Loaded Bigels

“…On the last day (D21), the smallest wound size was observed in animals from the G3 group (1.500 ± 0.548 mm). These observations could be associated with the positive effect of B/NLC-SJW on tissue recovery, previously demonstrated in an incisional wound model in rats [50].…”

“…The latter was incorporated into the selected blank NLC samples (in a concentration of 1.25 w/w%). The model based on GB and BO (HP-NLC) was selected as the preferable one on the grounds of the following observations (Figure 6) [50]:…”

“…Our previous works demonstrated the elaboration of stable, non-toxic bigels containing HP-rich SJW extract: "unprotected" (B/SJW) and incorporated into NLCs (B/NLC-SJW) [50,51]. The current study aims to investigate their effect on regenerative processes in rat skin using an excision wound model.…”

In Situ Gelling Behavior and Biopharmaceutical Characterization of Nano-Silver-Loaded Poloxamer Matrices Designed for Nasal Drug Delivery

“…The apparatus was equipped with a conical probe with a diameter of 40 mm. The motion of the probe was set at 3 mm·s −1 at pre-test and test runs; the insertion depth was 5 cm [ 49 ]. The means of three replicates were considered.…”

Characterization, Biocompatibility and Antioxidant Activity of Hydrogels Containing Propolis Extract as an Alternative Treatment in Wound Healing

“…The rheological properties of hydrogels were evaluated in relation to their tension/defo rmation and their behavior when exposed to shear stress (τ) and shear rate (γ). It is known that, as the materials flow, the friction among the molecules present in the material generates a force that gives rise to viscosity and that the greater the friction, the greater the force and the harder it becomes for the material to flow [41]. Therefore, the greater viscosity of hydrogels containing propolis extract reflects greater difficulty in fluidity.…”