Bacterial infection is one of the major factors contributing to the compromised healing in chronic wounds. Sometimes bacteria biofilms formed on the wound are more resistant than adherent bacteria. Cold atmosphere plasma (CAP) has already shown its potential in contact-free disinfection, blood coagulation, and wound healing. In this study, we integrated a multimodal imaging system with a portable CAP device for image-guided treatment of infected wound in vivo and evaluated the antimicrobial effect on Pseudomonas aeruginosa sample in vitro.15 ICR mice were divided into three groups for therapeutic experiments:(1) control group with no infection nor treatment (2) infection group without treatment (3) infection group with treatment. For each mouse, a three millimeters punch biopsy was created on the dorsal skin. Infection was induced by Staphylococcus aureus inoculation one day post-wounding. The treated group was subjected to CAP for 2 min daily till day 13. For each group, five fixed wounds’ oxygenation and blood perfusion were evaluated daily till day 13 by a multimodal imaging system that integrates a multispectral imaging module and a laser speckle imaging module. In the research of relationship between therapeutic depth and sterilization effect on P.aeruginosa in agarose, we found that the CAP-generated reactive species reached the depth of 26.7μm at 30s and 41.6μm at 60s for anti-bacterial effects. Image-guided CAP therapy can be potentially used to control infection and facilitate the healing process of infected wounds.
We introduce a microfluidic approach to simulate tumor hypoxia and vascular anomaly. Polydimethylsiloxane (PDMS) phantoms with embedded microchannel networks were fabricated by a soft lithography process. A dialysis membrane was sandwiched between two PDMS slabs to simulate the controlled mass transport and oxygen metabolism. A tortuous microchannel network was fabricated to simulate tumor microvasculature. A dual-modal multispectral and laser speckle imaging system was used for oxygen and blood flow imaging in the tumor-simulating phantom. The imaging results were compared with those of the normal vasculature. Our experiments demonstrated the technical feasibility of simulating tumor hypoxia and vascular anomalies using the proposed PDMS phantom. Such a phantom fabrication technique may be potentially used to calibrate optical imaging devices, to study the mechanisms for tumor hypoxia and angiogenesis, and to optimize the drug delivery strategies.
The wound healing process involves the reparative phases of inflammation, proliferation, and remodeling. Interrupting
any of these phases may result in chronically unhealed wounds, amputation, or even patient death. Despite the clinical
significance in chronic wound management, no effective methods have been developed for quantitative image-guided
treatment. We integrated a multimodal imaging system with a cold atmospheric plasma probe for image-guided
treatment of chronic wound. Multimodal imaging system offers a non-invasive, painless, simultaneous and quantitative
assessment of cutaneous wound healing. Cold atmospheric plasma accelerates the wound healing process through many
mechanisms including decontamination, coagulation and stimulation of the wound healing. The therapeutic effect of cold
atmospheric plasma is studied in vivo under the guidance of a multimodal imaging system. Cutaneous wounds are
created on the dorsal skin of the nude mice. During the healing process, the sample wound is treated by cold atmospheric
plasma at different controlled dosage, while the control wound is healed naturally. The multimodal imaging system
integrating a multispectral imaging module and a laser speckle imaging module is used to collect the information of
cutaneous tissue oxygenation (i.e. oxygen saturation, StO<sub>2</sub>) and blood perfusion simultaneously to assess and guide the plasma therapy. Our preliminary tests show that cold atmospheric plasma in combination with multimodal imaging
guidance has the potential to facilitate the healing of chronic wounds.