Thymoquinone loaded nanoemulgel in streptozotocin induced diabetic wound

<b>Aim:</b> To treat diabetic wound healing with a novel Thymoquinone (TQ) loaded nanoformulation by using combination of essentials oils. <b>Methods:</b> TQ nanoemulsion (NE) was developed with seabuckthorn &amp; lavender essential oils by phase inversion method and mixture design. Further, DIAGEL is obtained by incorporating NE into 1% carbopol^®934. Furthermore, particle size, polydispersity index, thermodynamic stability studies, rheology, spreadability, drug content, <i>in-vitro</i> drug release, <i>ex-vivo</i> permeation, anti-oxidant assay, antimicrobial studies, angioirritance, HAT-CAM assay, <i>in-vitro</i> and <i>in-vivo</i> studies were determined. <b>Results:</b> NE has a particle size of 17.79 ± 0.61 nm, 0.206 ± 0.012 PDI &amp; found to be thermodynamically stable. DIAGEL exhibited pseudoplastic behavior, sustained drug release, better permeation of TQ and a drug content of 98.54 ± 0.08%. DIAGEL stored for 6 months at room temperature and 2–8°C showed no degradation. Further, an improved angiogenesis, absence of angio-irritancy, remarkable antioxidant and antimicrobial activities against <i>Candida albicans</i> &amp; <i>S. aureus</i> were observed. Cytotoxicity analysis revealed nearly 2.28 -folds higher IC50 value than drug solution. Furthermore, inflammatory mediators were reduced in DIAGEL treated animal groups. The histopathological studies confirmed skin healing with regeneration and granulation of tissue. <b>Conclusion:</b> The novel formulation has strong anti-inflammatory, angiogenesis, antioxidant and appreciable diabetic wound healing properties. Diabetic foot ulcer is a skin-inflammatory disease condition characterized by high blood glucose levels, &amp; poor wound healing affecting mostly diabetic patients. Thymoquinone is a natural compound with anti-oxidant, anti-microbial, &amp; anti-inflammatory, low solubility makes it challenging for formulation development. Nanoemulgel containing combination of oils with high solubility of thymoquinone can be an ideal one. We employed pseudo ternary phase diagram for selection of S_mix ratio for developing annaoemlusion and to optimize the nanoemulsion we used here Randomized I-optimal mixture design, for characterization of nanoemulsion and nanoemulgel we used TEM, for gel properties we used here rheometer and texture analyzer. Developed nanoemulgel shows remarkable <i>in-vitro</i> antimicrobial activity against <i>Candida albicans</i> and <i>S. aureus</i> &amp; also stimulating angiogenesis &amp; negligible angioirritation by CAM assay. <i>In-vitro</i> cell lines studies were conducted on L929 cell to check the cytotoxicity of developed nanoformulation and also to check the cellular internalization, ROS, morphology, migration assay and apoptosis. In diabetic wound animal model nanoemulgel showed significant decreased levels of TNF-α, IL-6, MMP-9 and IL-1β. Histopathological studies also showed that absence of inflammatory cells, and granulation of tissue was seen. The amalgamation of these data strongly suggests that the nanoemulgel is a possible strategy for drug-delivery systems, with significant promising for the management of diabetic wound.