High Levels of Oxidative Stress and Skin Microbiome are Critical for Initiation and Development of Chronic Wounds in Diabetic Mice.

A balanced redox state is critical for proper healing. Although human chronic wounds are characterized by high levels of oxidative stress (OS), whether OS levels are critical for chronic wound development is not known. For these studies, we used our chronic wound model in diabetic mice that has similar characteristics as human chronic wounds, including naturally developed biofilm. We hypothesize that OS levels in wound tissues are critical for chronic wound initiation and development. We show that increased OS levels in the wound correlate with increased chronicity. Moreover, without increased OS levels, biofilm taken from chronic wounds and placed in new excision wounds do not create chronic wounds. Similarly, high OS levels in the wound tissue in the absence of the skin microbiome do not lead to chronic wounds. These findings show that both high OS levels and bacteria are needed for chronic wound initiation and development. In conclusion, OS levels in the wound at time of injury are critical for biofilm formation and chronic wound development and may be a good predictor of the degree of wound chronicity. Treating such wounds might be accomplished by managing OS levels with antioxidants combined with manipulation of the skin microbiome after debridement

Formulações de entrega de peptídeos antimicrobianos para a cicatrização de feridas

National Patent (INPI)A presente divulgação diz respeito a formulações de entrega de peptídeos antimicrobianos para a cicatrização de feridas, em particular diz respeito a uma composição que compreende pelo menos um polímero, pelo menos um péptido antimicrobiano compreendendo pelo menos uma sequência 95% idêntica à sequência seq. id 1, em particular idêntica à seq id 1. e com uma quantidade terapeuticamente eficaz de todos componentes anteriores.info:eu-repo/semantics/publishedVersio

Improved burn wound healing by the antimicrobial peptide LLKKK18 released from conjugates with dextrin embedded in a Carbopol gel

Antimicrobial peptides (AMPs) are good candidates to treat burn wounds, a major cause of morbidity, impaired life quality and resources consumption in developed countries. We took advantage of a commercially available hydrogel, Carbopol, a vehicle for topical administration that maintains a moist environment within the wound site. We hypothesized that the incorporation of LLKKK18 conjugated to dextrin would improve the healing process in rat burns. Whereas the hydrogel improves healing, LLKKK18 released from the dextrin conjugates further accelerates wound closure, and simultaneously improving the quality of healing. Indeed, the release of LLKKK18 reduces oxidative stress and inflammation (low neutrophil and macrophage infiltration and pro-inflammatory cytokines levels). Importantly, it induced a faster resolution of the inflammatory stage through early M2 macrophage recruitment. In addition, LLKKK18 stimulates angiogenesis (increased VEGF and microvessel development in vivo), potentially contributing to more effective transport of nutrients and cytokines. Moreover, collagen staining evaluated by Massons Trichrome was visually much more intense after treatment with LLKKK18, suggesting higher collagen deposition. Overall, we generated an effective, safe and inexpensive formulation that maintains a moist environment in the wound, easy to apply and remove, and with potential to prevent infection due to the presence of an antimicrobial peptide. These findings propel us to further study this LLKKK18-containing formulation, setting the foundations towards a potential therapeutic approach for burn wound treatment.Fundação Para a Ciência e Tecnologi

Biomedical applications of human cathelicidin

[Excerpt] Antimicrobial peptides (AMPs) are good candidates to treat burn wounds, a major cause of morbidity, impaired life quality and resources consumption in developed countries. Tuberculosis (TB), a disease caused by the human pathogen Mycobacterium tuberculosis, represents the second world’s deadliest infectious disease, affecting around 9 million people worldwide in 2013. Of those, about 1.1 million died from the disease. The potential of cathelicin, a human AMP, in the treatment of mycobacteriosis and wound regeneration was assessed in pre-clinical trials. (...

Challenges and opportunities in remote prototyping: a case-study during COVID-19

Collaboration is common practice within design disciplines and beyond. Brainstorming, discussions, and prototyping tend to occur within the same physical space. The reduction of human interaction during the COVID-19 pandemic disrupted these practices. In this paper, we focus on the possibilities and challenges of remote prototyping of four student teams by combining a double diamond approach with tools to overcome remote work challenges. The results were analyzed to understand crucial tools, advantages, and obstacles. The key challenges and opportunities were then identified and examined

Assessment of burn wound tissue in situ by multiphoton microscopy employing fluorescence and second harmonic generation contrasts in live animals

Current assessment of burn wound depth and progression of healing for proper choice of treatment is based on time-consuming and invasive techniques that may interfere with the healing process. One way to overcome these problems is to use noninvasive techniques. We use multiphoton microscopy (MPM) that employs fluorescence and second harmonic generation (SHG) contrasts to noninvasively follow the burn healing process in situ as healing progresses in live animals. Healing progression was followed in a partial thickness burn wound made on the dorsum of anesthetized Sprague-Dawley rats with a 2.8 cm diameter brass cylinder heated at 80oC for 60 seconds and pressed against the shaved rat skin for 6 seconds. During the first five days, burn healing was characterized by changes in the organization of collagen into a compact, mat-like assembly, suggesting progressive degradation of collagen within the injury site.We also detected increased follicular cell damage and a strong auto-fluorescence signal from cellular debris. Deposition of new collagen was seen after the scab fell off and gradually increased thereafter as detected with an increase in the SHG signal intensity. A great increase in the density of cells was observed as well. From day 21 on, a network of capillaries with blood flow was observed. The epidermal cell layer and the blood vessel network became progressively more organized. At day 29, fibrillar collagen had SHG signal levels and morphology of the nearly preburn state. These findings were corroborated by histology/histochemistry. In conclusion, MPM technology that employs fluorescence and SHG contrasts is instrumental in following the healing process, in particular during the early stages of healing. The degree and rate with which these events occur early after burning could help clinicians make treatment decisions. The outcomes of healing at later times would be indicative of the effectiveness of the treatment applied

Usefulness of the Reversible Jump Markov Chain Monte Carlo Model in Regional Flood Frequency Analysis

Regional flood frequency analysis is a convenient way to reduce estimation uncertainty when few data are available at the gauging site. In this work, a model that allows a non-null probability to a regional fixed shape parameter is presented. This methodology is integrated within a Bayesian framework and uses reversible jump techniques. The performance on stochastic data of this new estimator is compared to two other models: a conventional Bayesian analysis and the index flood approach. Results show that the proposed estimator is absolutely suited to regional estimation when only a few data are available at the target site. Moreover, unlike the index flood estimator, target site index flood error estimation seems to have less impact on Bayesian estimators. Some suggestions about configurations of the pooling groups are also presented to increase the performance of each estimator

Near-infrared proper motions and spectroscopy of infrared excess sources at the Galactic Center

There are a number of faint compact infrared excess sources in the central stellar cluster of the Milky Way. Their nature and origin is unclear. In addition to several isolated objects of this kind we find a small but dense cluster of co-moving sources (IRS13N) about 3" west of SgrA* just 0.5" north of the bright IRS13E cluster of WR and O-type stars. Based on their color and brightness, there are two main possibilities: (1) they may be dust embedded stars older than few Myr, or (2) extremely young, dusty stars with ages less than 1Myr. We present fist H- and Ks-band identifications or proper motions of the IRS13N members, the high velocity dusty S-cluster object (DSO), and other infrared excess sources in the central field. We also present results of NIR H- and Ks-band ESO-SINFONI integral field spectroscopy of ISR13N. We show that within the uncertainties, the proper motions of the IRS13N sources in Ks- and L'-band are identical. This indicates that the bright L'-band IRS13N sources are indeed dust enshrouded stars rather than core-less dust clouds. The proper motions show that the IRS13N sources are not strongly gravitationally bound to each other implying that they have been formed recently. We also present a first H- and Ks-band identification as well as proper motions and HKsL'-colors of a fast moving DSO which was recently found in the cluster of high speed S-stars that surround the super-massive black hole Sagittarius A* (SgrA*). Most of the compact L'-band excess emission sources have a compact H- or Ks-band counterpart and therefore are likely stars with dust shells or disks. Our new results and orbital analysis from our previous work favor the hypothesis that the infrared excess IRS13N members and other dusty sources close to SgrA* are very young dusty stars and that star formation at the GC is a continuously ongoing process.Comment: 20 pages, 18 figures, 4 tables plus appendix with 16 figures and 3 tables accepted by A&

Massive stars in the giant molecular cloud G23.3−0.3 and W41

Context. Young massive stars and stellar clusters continuously form in the Galactic disk, generating new Hii regions within their natal giant molecular clouds and subsequently enriching the interstellar medium via their winds and supernovae.Aims. Massive stars are among the brightest infrared stars in such regions; their identification permits the characterisation of the star formation history of the associated cloud as well as constraining the location of stellar aggregates and hence their occurrence as a function of global environment.Methods. We present a stellar spectroscopic survey in the direction of the giant molecular cloud G23.3−0.3. This complex is located at a distance of ~4–5 kpc, and consists of several Hii regions and supernova remnants.Results. We discovered 11 OfK+ stars, one candidate luminous blue variable, several OB stars, and candidate red supergiants. Stars with K-band extinction from ~1.3–1.9 mag appear to be associated with the GMC G23.3−0.3; O and B-types satisfying this criterion have spectrophotometric distances consistent with that of the giant molecular cloud. Combining near-IR spectroscopic and photometric data allowed us to characterize the multiple sites of star formation within it. The O-type stars have masses from ~25–45 M⊙, and ages of 5–8 Myr. Two new red supergiants were detected with interstellar extinction typical of the cloud; along with the two RSGs within the cluster GLIMPSE9, they trace an older burst with an age of 20–30 Myr. Massive stars were also detected in the core of three supernova remnants – W41, G22.7−0.2, and G22.7583−0.4917.Conclusions. A large population of massive stars appears associated with the GMC G23.3−0.3, with the properties inferred for them indicative of an extended history of stars formation