PMC

AZD8601 treatment resulted in increased oxygenation of diabetic wound beds during healing. (A) Black and white ratiometric images of fluorescence/phosphorescence signal from BF₂nbm(I)PLA (Difluoroboron β-diketonate poly(lactic acid)) nanoparticles revealed increased oxygenation in AZD8601-treated wounds. (B) Wound oxygenation as calculated by mean gray value of ratiometric images was significantly increased at day 6 post-surgery in the AZD8601-treated group. (C) Addition of BF₂nbm(I)PLA nanoparticles to wounds did not impair healing. **p < 0.01, n = 3–4/group.

Repeated and higher doses of AZD8601 had greater effects on diabetic wound healing. (A) Dosing on days 0 and 3 increased early healing compared to dosing on day 0 only (n = 7–8/group). (B) The greatest effect on wound closure was achieved by the 200 µg dose of AZD8601, which came closest to replicating the effect of exogenous recombinant VEGF-A₁₆₅ protein positive control (n = 6/group). *p < 0.05, **p < 0.01, ***p < 0.001.

(A) Time-lapse multi-parametric photoacoustic microscopy of microvascular responses to 100 µg of AZD8601 or Non-Translatable(NT)-VEGF-A mRNA intradermally injected to the mouse ear. The top, middle and bottom rows respectively show the microvascular structure, sO₂ and blood flow speed. PA: photoacoustic. (B) Statistical comparison of the multifaceted microvascular responses in diameter, volumetric flow, oxygen extraction fraction (OEF), and oxygen metabolism to AZD8601, VEGF-A protein, NT-VEGF-A mRNA, and citrate/saline vehicle (n = 8/group). *p < 0.05, **p < 0.01, ***p < 0.001, and ****p < 0.0001.

Time-lapse multi-parametric photoacoustic microscopy of microvascular responses to sequential dosing of (A) 100 µg AZD8601 or (B) saline vehicle intradermally injected to the mouse ear on day 0, 2 and 4. The top, middle and bottom rows respectively show the microvascular structure, sO₂ and blood flow speed. PA: photoacoustic. (C) Statistical comparison of the multifaceted microvascular responses in diameter, volumetric flow, oxygen extraction fraction (OEF), and oxygen metabolism to single and multiple injections of AZD8601 and citrate/saline vehicle (n = 4/group). *p < 0.05, **p < 0.01, ***p < 0.001, and ****p < 0.0001.

Transfection efficiency, pharmacokinetic characterization, and hybridization of AZD8601. (A) AZD8601 or Non-Translatable(NT)-VEGF-A mRNA was transfected into human aortic smooth muscle cells with Lipofectamine 2000 as transfection reagent. After 4 hours the transfection medium was removed and changed to fresh serum free media that was changed every 8 hours. At 24 hours the medium was collected and kept at −80 °C for subsequent measurement of human VEGF-A protein. Levels of VEGF-A protein produced are normalized to levels produced by AZD8601 (n = 3/group). (B) Maximum concentration of VEGF-A protein (Cmax) after intradermal injection in db/db mice of 10, 100 and 300 µg of AZD8601 in citrate/saline (n = 6/dose group, left panel). Human VEGF-A protein content in skin biopsies up to 144 hours after intradermal injection of 100 µg citrate/saline-formulated AZD8601 in db/db mice. The line represents the median at each time point (n = 3–8/time point, right panel). (C) In situ hybridization staining for AZD8601 (brown color in the upper panel) and immunohistochemistry staining for human VEGF-A protein (magenta color and black arrows in the lower panel) after intradermal injection of 100 µg AZD8601 in citrate/saline formulation as a function of time up to 144 hours. Magnification is 400x.