Bioactive nanoparticle-based formulations increase survival area of perforator flaps in a rat model

Abstract

BackgroundDistal flap necrosis is a frequent complication of perforator flaps. Advances in nanotechnology offer exciting new therapeutic approaches. Anti-inflammatory and neo-angiogenic properties of certain metal oxides within the nanoparticles, including bioglass and ceria, may promote flap survival. Here, we explore the ability of various nanoparticle formulations to increase flap survival in a rat model.Materials and methodsA 9 x 3 cm dorsal flap based on the posterior thigh perforator was raised in 32 Lewis rats. They were divided in 4 groups and treated with different nanoparticle suspensions: I–saline (control), II–Bioglass, III–Bioglass/ceria and IV–Zinc-doped strontium-substituted bioglass/ceria. On post-operative day 7, planimetry and laser Doppler analysis were performed to assess flap survival and various samples were collected to investigate angiogenesis, inflammation and toxicity.ResultsAll nanoparticle-treated groups showed a larger flap survival area as compared to the control group (69.9%), with groups IV (77,3%) and II (76%) achieving statistical significance. Blood flow measurements by laser Doppler analysis showed higher perfusion in the nanoparticle-treated flaps. Tissue analysis revealed higher number of blood vessels and increased VEGF expression in groups II and III. The cytokines CD31 and MCP-1 were decreased in groups II and IV.ConclusionsBioglass-based nanoparticles exert local anti-inflammatory and neo-angiogenic effects on the distal part of a perforator flap, increasing therefore its survival. Substitutions in the bioglass matrix and trace metal doping allow for further tuning of regenerative activity. These results showcase the potential utility of these nanoparticles in the clinical setting.

Inorganic nanohybrids combat antibiotic-resistant bacteria hiding within human macrophages

“…32 Apart from silver-based systems, materials of interest include the biodegradable material bioglass (a blend of SiO 2 , CaO, Na 2 O, and P 2 O 5 ). Bioglass has been widely used in the biomedical field for soft (especially with the incorporation of Sr into the bioglass matrix) and hard tissue applications [33][34][35] and has exhibited antimicrobial properties in nanoparticulate form. 36 Similarly, cerium oxide (ceria, CeO 2 ) nanoparticles have documented antimicrobial properties, which strongly depend on material characteristics, including the Ce 3+ /Ce 4+ surface ratio, and environmental factors, such as pH and the presence of phosphate.…”

“…The study is focused on metal-oxide nanoparticles based on bioglass (BG), ceria, hybrids of the bioglass and cerium oxide (BG/ ceria), and 2% Zn-doped Sr-substituted hybrids (Zn2-SrBG/ ceria), building on their high biocompatibility and potential for wound healing. 33 Despite their sophisticated formulation, all nanoparticles were produced in a single step using liquidfeed flame spray pyrolysis (LF-FSP), a highly scalable nanoparticle production method. 42 Additionally, silver-based systems based on X% Ag-doped bioglass (AgX-BG, X = 0.1, 0.5, Scheme 1 Intracellular infections are hard to treat with conventional antibiotics due to their poor membrane permeability.…”

Uniting Drug and Delivery: Metal Oxide Hybrid Nanotherapeutics for Skin Wound Care

“…The increased survival area was most likely due to the angiogenic properties of the nanoparticles and the resulting higher tissue perfusion (adapted from Lese at al. [108]). (b) By engineering the architecture Figure 6.…”

“…Both elements and their oxides have shown anti-inflammatory and, more importantly, angiogenic properties [ 104 , 105 , 106 , 107 ]. In a perforator flap study in rats, these nanoparticles significantly increased healing, most probably due to an increased perforation of the skin flap ( Figure 6 a) [ 108 ]. To address the phases of the wound healing cascade in an ideal way, temporal control of the material activities is pivotal.…”

“…The increased survival area was most likely due to the angiogenic properties of the nanoparticles and the resulting higher tissue perfusion (adapted from Lese at al. [ 108 ]). ( b ) By engineering the architecture and structure of a metal oxide nanotherapeutic, the temporal control of material activity can be achieved.…”