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Objective: Cardiac pacemakers must be regularly replaced due to depleted batteries. A possible alternative is proposed by subcutaneous photovoltaic energy harvesting. The body's reaction to an implant can cause device encapsulation. Potential changes in spectral light transmission of skin can influence the performance of subcutaneous photovoltaic cells and has not yet been studied in large animal studies. Methods: Subcutaneous implants measuring changes in the light reaching the implant were developed. Three pigs received those implants and were analyzed for seven weeks. Spectral measurements with known irradiation were performed to identify possible changes in the transparency of the tissues above the implant during the wound healing process. A histological analysis at the end of the trial investigated the skin tissue above the subcutaneous photovoltaic implants. Results: The implants measured decreasing light intensity and shifts in the light's spectrum during the initial wound healing phase. In a later stage of tissue recovery, the implants measured a generally reduced light intensity compared to the healthy tissue after implantation. The spectral distribution of the measured light at the end of the trial was similar to the first measurements. The histological analysis showed subcutaneous granulation tissue formation for all devices. Conclusion: The varying reduction of light intensity reaching the implants means that safety margins must be sufficiently high to ensure the power. At the end of the wound healing process, the spectral distribution of the light reaching the implant is similar to healthy tissue. Significance: Optimizations of spectral sensitivity of photovoltaic cells are possible. [ABSTRACT FROM AUTHOR]

Surgical incision infection of multidrug-resistant microorganisms (e.g., methicillin-resistant Staphylococcus aureus, MRSA) is a severe cause of poor wound healing, which is prevalent in healthcare facilities and constitutes a huge infectious disease burden in the world. The purpose of this study is to investigate the medical application and possible mechanisms of the cold atmospheric plasma jet on infected wounds. In this article, the New Zealand rabbit in vivo wound infected with MRSA is used as the wound healing animal model. The helium atmospheric-pressure dielectric-barrier-discharge (AP-DBD) plasma jet is employed to treat the wounds infected with MRSA. The wound healing, histological, and cytokine analyses are conducted to evaluate the efficacy of the helium AP-DBD plasma jet on the MRSA-infected wound healing process. The experimental results show that the helium AP-DBD plasma jet treatment on the wounds infected with MRSA can regulate the secretion of the cytokines, limit the inflammatory response and cell excessive proliferation, accelerate the process of re-epithelialization, and consequently, promote the wound healing process and the inactivation of the bacteria. [ABSTRACT FROM AUTHOR]

Objective: an innovative non−thermal plasma (NTP) system constituted by a radiofrequency (RF) power generator directly coupled to a treatment probe is described and characterized. This system is intended to be applied as a medical device for therapeutic treatments. Methods: electrical characterization of the radiofrequency power generator supplying the treatment probe was performed. Meanwhile, generated NTP was optically analyzed. Obtained data were studied to establish the safety profile of plasma application on heat sensitive matter. Results: the NTP system was validated through bacterial deactivation trials, as well as, of being capable of deactivating carcinogenic cells. Besides promoting and accelerating wound closure in vivo performed in mice, demonstrating faster healing than that done with conventional treatments. Conclusion: the NTP system's characterization is an essential stage to determine the adequate application of the generated plasma over organic media. The therapeutic benefits of the NTP system were proved by the development of in vivo experiences involving laboratory mice. Significance: the generated NTP interacts with surrounding air particles producing reactive oxygen and nitrogen species, which, exhibit bactericidal and antiseptic effects due to their strong biochemical reactivity; functioning like critical mediators in animal physiology and promoting wound healing processes. These properties make the NTP system a feasible technology intended for therapeutic treatments. [ABSTRACT FROM AUTHOR]

Chronic wounds are a major complication for diabetes mellitus (DM) patients, which cause discomfort and an increase in medical costs. The purpose of this study is to investigate the medical application and possible mechanisms of a cold atmospheric plasma jet in healing DM chronic wounds. In this paper, the genetic diabetic BKS.DB mice are used as the diabetic wound healing animal model, which have a stable glucose level and can avoid the effects or complications induced by surgical and chemical interventions. The helium atmospheric-pressure dielectric-barrier-discharge (AP-DBD) plasma jet is employed to treat the diabetic mice wounds with the fixed treatment time and distance of 15 s and 20.0 mm, respectively. The wound healing, histological, immunohistochemical, and cytokine analyses are conducted to evaluate the efficacy of the helium AP-DBD plasma jet on the chronic wound healing of the genetic diabetic mice. The experimental results show that the helium AP-DBD plasma jet treatment of wounds of genetic diabetic mice can regulate the secretion of transforming growth factor- $\beta $ (TGF- $\beta$) and fibroblast growth factors (FGFs), limit the inflammatory response and excessive cell proliferation, accelerate the process of re-epithelialization, and consequently, promote the chronic wound healing process. [ABSTRACT FROM AUTHOR]

A plasma jet enhanced oil-based drug, named plasma-activated oil (PAO) is produced in sunflower oil by a single-step, room temperature, energy-efficient, and environment-friendly dry plasma jet enabled process. Plasma jets with two different working gas combinations, argon + air and argon + O2, were generated, namely PAO (air) and PAO (O2), respectively. Several hours of plasma jet treatment substantially increased the hydrogen peroxide and carboxylic acid concentrations in the PAO. Although the electrophilic fatty acid nitroalkenes produced by nitric oxide and nitrite of the argon + air plasma jet increased the acid value of PAO (air), similar sterilization and wound healing effect suggest that PAO (air) and PAO (O2) have similar concentrations of hydrogen peroxide and carboxylic acid. PAO killed the common Gram-positive bacteria [methicillin-resistant staphylococcus aureus (MRSA) and Micrococcus luteus] and Gram-negative bacteria (Pseudomonas aeruginosa and Escherichia coli) efficiently. PAO accelerated the healing of infected wounds by 33%. [ABSTRACT FROM AUTHOR]

The aim of this experiment is to enhance selected species in atmospheric pressure plasma jet (APPJ) that might be helpful for the wound healing purpose and to test the performance using basic diagnosis in plasma-treated liquid. A homemade APPJ device is driven by sinusoidal voltage with a excitation frequency of 25 kHz. Argon with admixture of small percentage of nitrogen, oxygen, and water vapor was selected to be carrier gas as the main sources of reactive species. Discharge power consumption is calculated by two approaches. Reactive oxygen species and reactive nitrogen species in the excited states are characterized by optical emission spectroscopy (OES). Excitation temperature $T_{\mathrm {exc}}$ in argon plasmas is calculated to estimate the electron energy distribution. The results show that argon plasmas with small addition of nitrogen and oxygen in this jet configuration are more efficient to generate desired reactive species in terms of OES diagnosis and liquid acidification. Moreover, the distinct efficiency of liquid acidification between direct and indirect plasma treatment of liquid has also been observed. [ABSTRACT FROM AUTHOR]

In this paper, we separately fabricated the poly ($\varepsilon $ -caprolactone) (PCL) scaffolds containing epidermal growth factor (EGF) by using our-self fabricated electrospinning machine for tissue regeneration application. Several fundamental properties, including the dimensions, wettability, and EGF release profiles, of the fabricated EGF-PCL bead, fibrous, and multistructured scaffolds were characterized by using the scanning electron microscopy (SEM), contact angle goniometer, and vertical diffusion system. The EGF release profiles of three scaffolds were measured for 200 h, and the multistructured scaffold performed stable and long EGF release properties. Furthermore, the in vitro and in vivo experiments were conducted to evaluate the performance of three types of EGF-PCL scaffolds. The NIH-3T3 fibroblast cells were cultured on the scaffolds to study the effects of the released EGF by using the Alamar Blue Cell Viability Assays, fluorescence image analysis, and SEM. The animal experiment demonstrated that the multistructured EGF-PCL scaffold achieved 95% of the wound healing rate to the cut-damaged wounds after 16 days. Moreover, the histopathological skin tissue showed that the wound regenerated well after the treatment of the multistructured EGF-PCL scaffold. The developed multistructured EGF-PCL scaffold has a high potential for the wound healing applications. [ABSTRACT FROM AUTHOR]

Plasma medicine is a rapidly advancing field. As one promising application, cold plasma has been ascribed a beneficial role in wound healing in which monocytes/macrophages play an important part. Wound healing and many other physiological and pathological processes are subject to redox control. Cold plasma expels reactive species of many kinds, thereby altering the redox state and mediating cell and tissue responses. Controlling this species efflux could be a valuable asset to control biological effects. We, therefore, investigated the biological response of a plasma treatment regimen that was gas shielded from the ambient environment. In this gas curtain, several N2:O2 ratios were investigated, and we discovered a modulation within the composition of active compounds (NO-2 , NO-3 , and H2O2) in physiological solutions. Using a human monocyte cell line, the cell's scavenging activity toward these molecules was assessed. With regard to cellular processes important in wound healing, such as cytokines release, O2 shielding provided stronger stimulation compared to N2 shielding. Altogether, the results support the idea that tuning the plasma-derived reactive species composition may be an interesting approach to improve plasma medical applications. [ABSTRACT FROM AUTHOR]

Nano-patterned oxidized porous silicon (PS) substrates are topographically biocompatible to provide in vitro environment for improved understanding of in vivo wound healing behavior. But the wound healing studies reported on various featured substrates are mainly based on time lapse microscopy coupled with fluorescent labeling. This study is the first attempt to perform continuous monitoring of wound healing phenomena using PS substrates with two pore morphologies by means of impedance measurement. A distributed electrical model has been developed for the PS substrates to extract the cell migration rate, proliferation rate, and time-dependent coverage of cell free area. It has been observed from impedance measurements and from model that the wound closure is faster on 50 nm pores followed by 500 nm pores and planar ECIS substrates. This has been qualitatively explained from the extracted time-dependent cell–cell and cell-substrate interaction parameters using a well-known mechanical model of wound healing process. The electrical readings have been closely correlated with scanning electron microscopy (SEM) and optical microscopy images. Thus, the impedance spectroscopy method coupled with the proposed theoretical framework can provide information about the underlying mechanisms of wound regeneration on nano-patterned substrates in a non-invasive manner. [ABSTRACT FROM PUBLISHER]

Clinical data from human chronic wounds implicates biofilm formation with the onset of wound chronicity. Despite the development of novel antimicrobial agents, the cost and complexity of treating chronic wound infections associated with biofilms remain a serious challenge, which necessitates the development of new and alternative approaches for effective anti-biofilm treatment. Recent advancement in nanotechnology for developing a new class of nanoparticles that exhibit unique chemical and physical properties holds promise for the treatment of biofilm infections. Over the last decade, nanoparticle-based approaches against wound biofilm infection have been directed toward developing nanoparticles with intrinsic antimicrobial properties, utilizing nanoparticles for controlled antimicrobials delivery, and applying nanoparticles for antibacterial hyperthermia therapy. In addition, a strategy to functionalize nanoparticles towards enhanced penetration through the biofilm matrix has been receiving considerable interest recently by means of achieving an efficient targeting to the bacterial cells within biofilm matrix. This review summarizes and highlights the recent development of these nanoparticle-based approaches as potential therapeutics for controlling wound biofilm infection, along with current challenges that need to be overcome for their successful clinical translation. [ABSTRACT FROM PUBLISHER]

We evaluated a nonthermal plasma jet for a respective use to prevent infections from bacteria and yeasts. The plasma jet is generated from the flow of ambient air with 8 slm through a microhollow cathode discharge assembly that is operated with a direct current of 30 mA. With these parameters, the temperature in the jet reaches 43 ^\circ\C at 10 mm from the discharge. Agar plates that were inoculated with Staphylococcus aureus, Pseudomonas aeruginosa, Acinetobacter baumannii, and Candida kefyr were treated at this distance, moving the plates through the jet in a meander that covered a 2 cm by 2 cm area. Different exposure times were realized by changing the speed of the movement and adjusting the distance between consecutive passes. S. aureus was most responsive to the exposure with a reduction in the number of colony forming units of 5.5 log steps in 40 s. All other microorganisms show a more gradual inactivation with exposure times. For all bacteria, a clearing of the treated area is achieved in about 2.5–3.5 min, corresponding to log-reduction factors of 5.5–6.5. Complete inactivation of the yeast requires about 7 min. Both S. aureus and C. kefyr show considerable inactivation also outside the immediate treatment area, while P. aeruginosa and A. baumannii do not. We conclude that differences in the morphologies of the membrane structures are responsible for the diverging results, together with a targeted response to different agents provided with the plasma jet. For the gram negative bacteria, we hold short-lived agents, acting across a short range, responsible, while for the other microorganisms, longer lived species seem more important. Our measurements show that neither heat, ultraviolet radiation, nor the generation of ozone can be responsible for the observed results. The most prominent long lived reaction product found is nitric oxide, which, by itself or through induced chemical reactions, might affect cell viability. [ABSTRACT FROM PUBLISHER]

The design and the electric and emission characteristics of a handheld air plasma spray are presented. The plasma is generated by 60-Hz periodic discharges between two concentrically cylindrical electrodes. A ring magnet is used to rotate arc discharges, which sprays outward by an airflow. The rotation of arc discharges keeps the generated plasma in nonequilibrium state and at relatively low temperature (\sim \!\!55\ ^\circ\C). The plasma effluent still contains high-energy electrons which dissociate molecular oxygen into atomic oxygen. The emission spectroscopy of the plasma plume reveals that the plasma effluent, which carries abundant atomic oxygen, extends from the cap of the plasma spray about 25 mm. Using pigs as the animal model, in vivo tests of stopping wound bleeding and postoperative observation of wound healing by this air plasma spray were performed. The results show that the bleeding from a cut to an ear artery is stopped swiftly; this air plasma spray also shortens wound healing time to about half (from 14 days to 8 days) after stopping the bleeding of a cross-cut wound in the ham area. [ABSTRACT FROM AUTHOR]

With the widespread use of digital cameras, freehand wound imaging has become common practice in clinical settings. There is however still a demand for a practical tool for accurate wound healing assessment, combining dimensional measurements and tissue classification in a single user-friendly system. We achieved the first part of this objective by computing a 3-D model for wound measurements using uncalibrated vision techniques. We focus here on tissue classification from color and texture region descriptors computed after unsupervised segmentation. Due to perspective distortions, uncontrolled lighting conditions and view points, wound assessments vary significantly between patient examinations. The main contribution of this paper is to overcome this drawback with a multiview strategy for tissue classification, relying on a 3-D model onto which tissue labels are mapped and classification results merged. The experimental classification tests demonstrate that enhanced repeatability and robustness are obtained and that metric assessment is achieved through real area and volume measurements and wound outline extraction. This innovative tool is intended for use not only in therapeutic follow-up in hospitals but also for telemedicine purposes and clinical research, where repeatability and accuracy of wound assessment are critical. [ABSTRACT FROM AUTHOR]

Cold plasma treatment of wounds is gaining much interest, because it will offer a noncontact, painless, and harmless therapy to manage large-area lesions (burn wounds and chronic ulcerations). One of the important issues in plasma wound healing is the safety of the method. In this paper, we study in vitro the effects of plasma treatment on cell death, proliferation, and wound healing. We performed a parametric study of plasma-treated 3T3 fibroblast cells. For the treatment, a cold atmospheric plasma needle (13.56-MHz microjet in helium) was used. Cells were cultured in six well plates and subsequently deposited on the bottom of the well. As a wound model, a scratch was made in the cell culture. Then, the proliferation of the cells from the sidewalls into the scratch was observed by microscopy. It appeared that plasma treatment stimulates the proliferation of cells into the scratch. This suggests that plasma treatment could result in accelerated wound healing. [ABSTRACT FROM AUTHOR]