Improved skin oxygenation after benzyl nicotinate application in different carriers as measured by EPR oximetry in vivo

Krzic, M; Šentjurc, Marjeta; Kristl, Julijana

doi:10.1016/s0168-3659(00)00351-5

Cited by 49 publications

(7 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The sensitivity to O 2 pressure is estimated at 5 mbar, comparable to that of some commercially available charcoals for EPR oximetry. [28][29][30] The sensitivity and ease of line width evaluation of this oxygen sensing system would, however, considerably be improved if the paramagnetic probe ion would exhibit a simpler EPR spectrum. Ti III , with S = 1/2 and 87% natural abundance in isotopes with I = 0, might present an interesting alternative.…”

Section: O 2 Sensingmentioning

confidence: 99%

Sensing the framework state and guest molecules in MIL-53(Al) via the electron paramagnetic resonance spectrum of V^IV dopant ions

Nevjestić

Depauw

Gast

et al. 2017

Phys. Chem. Chem. Phys.

View full text Add to dashboard Cite

X-ray diffraction (XRD) and electron paramagnetic resonance spectroscopy (EPR) were combined to study the structural transformations induced by temperature, pressure and air humidity of the "breathing" metal-organic framework (MOF) MIL-53(Al), doped with paramagnetic V ions, after activation. The correlation between in situ XRD and thermogravimetric analysis measurements showed that upon heating this MOF in air, starting from ambient temperature and pressure, the narrow pore framework first dehydrates and after that makes the transition to a large pore state (lp). The EPR spectra of V[double bond, length as m-dash]O molecular ions, replacing Al-OH in the structure, also allow to distinguish the as synthesized, hydrated (np-h) and dehydrated narrow pore (np-d), and lp states of MIL-53(Al). A careful analysis of EPR spectra recorded at microwave frequencies between 9.5 and 275 GHz demonstrates that all V[double bond, length as m-dash]O in the np-d and lp states are equivalent, whereas in the np-h state (at least two) slightly different V[double bond, length as m-dash]O sites exist. Moreover, the lp MIL-53(Al) framework is accessible to oxygen, leading to a notable broadening of the V[double bond, length as m-dash]O EPR spectrum at pressures of a few mbar, while such effect is absent for the np-h and np-d states for pressures up to 1 bar.

show abstract

Section: O 2 Sensingmentioning

confidence: 99%

Sensing the framework state and guest molecules in MIL-53(Al) via the electron paramagnetic resonance spectrum of V^IV dopant ions

Nevjestić

Depauw

Gast

et al. 2017

Phys. Chem. Chem. Phys.

View full text Add to dashboard Cite

show abstract

“…Moreover, the technique does not consume oxygen contrarily to microelectrodes and, consequently, it does not modify the environment where the pO 2 is measured. EPR oximetry was previously used to monitor oxygenation in several types of tissues [ 18 ] such as brain [ 21 – 28 ], heart [ 29 – 34 ], gastrointestinal tract [ 35 ], skeletal muscle [ 36 – 38 ], liver [ 39 – 45 ], kidneys [ 46 ] and skin [ 47 – 49 ], to characterize the tumor microenvironment [ 50 , 51 ], to measure oxygenation in ovarian grafts [ 52 ] and bone fractures [ 53 – 55 ]. Although EPR oximetry may be beneficial for studying the implication of oxygen during the healing process [ 56 ], to the best of our knowledge only 2 publications in the scientific literature have reported such application [ 57 , 58 ].…”

Section: Introductionmentioning

confidence: 99%

Application of Electron Paramagnetic Resonance (EPR) Oximetry to Monitor Oxygen in Wounds in Diabetic Models

et al. 2015

View full text Add to dashboard Cite

A lack of oxygen is classically described as a major cause of impaired wound healing in diabetic patients. Even if the role of oxygen in the wound healing process is well recognized, measurement of oxygen levels in a wound remains challenging. The purpose of the present study was to assess the value of electron paramagnetic resonance (EPR) oximetry to monitor pO2 in wounds during the healing process in diabetic mouse models. Kinetics of wound closure were carried out in streptozotocin (STZ)-treated and db/db mice. The pO2 was followed repeatedly during the healing process by 1 GHz EPR spectroscopy with lithium phthalocyanine (LiPc) crystals used as oxygen sensor in two different wound models: a full-thickness excisional skin wound and a pedicled skin flap. Wound closure kinetics were dramatically slower in 12-week-old db/db compared to control (db/+) mice, whereas kinetics were not statistically different in STZ-treated compared to control mice. At the center of excisional wounds, measurements were highly influenced by atmospheric oxygen early in the healing process. In pedicled flaps, hypoxia was observed early after wounding. While reoxygenation occurred over time in db/+ mice, hypoxia was prolonged in the diabetic db/db model. This observation was consistent with impaired healing and microangiopathies observed using intravital microscopy. In conclusion, EPR oximetry using LiPc crystals as the oxygen sensor is an appropriate technique to follow wound oxygenation in acute and chronic wounds, in normal and diabetic animals. Nevertheless, the technique is limited for measurements in pedicled skin flaps and cannot be applied to excisional wounds in which diffusion of atmospheric oxygen significantly affects the measurements.

show abstract

“…EPR oximetry has been widely used over the last decade to quantify oxygen pressure in the brain (Hou et al 2003), heart (Kuppusamy and Zweier 2004), gastrointestinal tract (He et al 1999), skeletal muscle (Jordan et al 2004, Aragonés et al 2008, liver (Gallez et al 1998, James et al 2002, kidneys (James et al 1996), skin (Krzic et al 2001) and tumours (Goda et al 1996, Gallez et al 1999, Jordan et al 2000. The technique is based on the introduction of an oxygen sensor into the tissue of interest a few hours before the measurement.…”

Section: Introductionmentioning

confidence: 99%

Retrievable micro-inserts containing oxygen sensors for monitoring tissue oxygenation using EPR oximetry

2008

View full text Add to dashboard Cite

Tissue oxygenation is a crucial parameter in various physiopathological situations and can influence the therapeutic response of tumours. EPR oximetry is a reliable method for assessing and monitoring oxygen levels in vivo over long periods of time. Among the different paramagnetic oxygen sensors available for EPR oximetry, lithium phthalocyanine (LiPc) is a serious candidate for in vivo applications because of its narrow linewidth and its high signal-to-noise ratio. To enhance the biocompatibility of the sensors, fluoropolymer Teflon AF2400 was used to make cylindrical micro-inserts containing LiPc crystals. This new micro-pellet design has several advantages for in vivo studies, including the possibility of being able to choose the implant size, a high sensor content, the facility of in vivo insertion and complete protection with preservation of the oxygen sensor's characteristics. The response to oxygen and the kinetics of this response were tested using in vivo EPR: no differences were observed between micro-inserts and uncoated LiPc crystals. Pellets implanted in vivo in muscles conserved their responsiveness over a long period of time (approximately two months), which is much longer than the few days of stability observed using LiPc crystals without protection by the implant. Finally, evaluation of the biocompatibility of the implants revealed no inflammatory reaction around the implantation area.

show abstract

Improved skin oxygenation after benzyl nicotinate application in different carriers as measured by EPR oximetry in vivo

Cited by 49 publications

References 15 publications

Sensing the framework state and guest molecules in MIL-53(Al) via the electron paramagnetic resonance spectrum of V^IV dopant ions

Sensing the framework state and guest molecules in MIL-53(Al) via the electron paramagnetic resonance spectrum of V^IV dopant ions

Application of Electron Paramagnetic Resonance (EPR) Oximetry to Monitor Oxygen in Wounds in Diabetic Models

Retrievable micro-inserts containing oxygen sensors for monitoring tissue oxygenation using EPR oximetry

Contact Info

Product

Resources

About

Improved skin oxygenation after benzyl nicotinate application in different carriers as measured by EPR oximetry in vivo

Cited by 49 publications

References 15 publications

Sensing the framework state and guest molecules in MIL-53(Al) via the electron paramagnetic resonance spectrum of VIV dopant ions

Sensing the framework state and guest molecules in MIL-53(Al) via the electron paramagnetic resonance spectrum of VIV dopant ions

Application of Electron Paramagnetic Resonance (EPR) Oximetry to Monitor Oxygen in Wounds in Diabetic Models

Retrievable micro-inserts containing oxygen sensors for monitoring tissue oxygenation using EPR oximetry

Contact Info

Product

Resources

About

Sensing the framework state and guest molecules in MIL-53(Al) via the electron paramagnetic resonance spectrum of V^IV dopant ions

Sensing the framework state and guest molecules in MIL-53(Al) via the electron paramagnetic resonance spectrum of V^IV dopant ions