Effective Management Of Topical Nosocomial Aspergillus Spp. Infections In Three Severely Burned Patients.

Nosocomial opportunistic fungal infections by Aspergillus spp. represent increasing morbidity and mortality factors for severely burned patients, who are fragile and immunocompromised. Voriconazole (VRC), a modern antifungal drug, is used as a first-line therapy against systemic mold and yeast infections. Little has been published about the place, relative importance and efficacy of voriconazole in the treatment protocols involving Aspergillus spp. in Burn Centers. The objective of the present work was to assess the place and importance of voriconazole for the treatment of burn patients presenting superficial Aspergillus spp. infections. We performed a retrospective evaluation of VRC treatment in three severely burned patients with superficial nosocomial Aspergillus spp. infections in our Burn Center. Results showed that VRC allowed for control and cure of topical nosocomial Aspergillus spp. infections. In two cases, treatment with VRC had to be discontinued because of hepatotoxicity. In two cases, following or during systemic treatment with VRC, a 1% terbinafine cream was applied to resolve the infection in order to continue standard wound management. Overall, VRC has been shown to be an effective antifungal agent and is an alternative to amphotericin B to fight Aspergillus spp. infections developing in the wounds of severely burned patients.

La survenue d'une aspergillose chez les patients gravement brûlés, dès lors immunodéprimés, est une cause de morbidité et de mortalité. Le voriconazole (VRC) est un antifongique utilisé en première intention dans le traitement des infections à moisissures. La littérature est pauvre au sujet de son utilisation dans l'aspergillose chez le brûlé. Cette étude a pour but de l 'évaluer dans le traitement de l'aspergillose cutanée chez le brûlé et a consisté en l'évaluation rétrospective de la prise en charge de trois patients de notre CTB, gravement brûlés et victimes d'une aspergillose cutanée. VRC en a permis la guérison, mais a dû être suspendu 2 fois en raison d'une toxicité hépatique. Dans 2 cas, il a été associé à de la crème de terbinafine à 1%. Le traitement habituel a pu être repris après guérison de l'aspergillose. Globalement, VRC semble efficace et représente une alternative à l'amphotéricine B dans le traitement de l'aspergillose cutanée chez les brûlés.

Acceptation of Folk Medicine and its "secrets" in a Swiss Burn Centre.

In Switzerland 'Secret' is a folk medicine called upon for burns. It has belonged to UNESCO's intangible cultural heritage since 2012. It is supposed to ease pain and accelerate the healing process of burns. As the practice is widely used in the population, this observational study investigated the opinion of caregivers and patients from the National Burn Center of Lausanne. Qualitative observational study based on a survey including ten questions aimed at identifying the professionals' perception of the phenomenon. Questions were developed from repeated encounters in the burn center. Data collection took five months. Thirty-six healthcare professionals (HP) and 12 selected patients (or parents for minors) discharged after burns were interviewed on a voluntary basis: all of the HPs knew about 'Secret' from the workplace, and 26 from home: 33 were convinced that it might be useful and reduce pain. The perceived efficiency of the practice (36 respondents) differs depending on professional category and personal experience. Only one HP considered the practice to be dangerous. The nurses and auxiliary nurses expressed that it should be used more widely. The 12 patients considered it as a complementary step, not a replacement for medical care. Health professionals globally considered this practice safe and helpful. The patients were interested in using parallel approaches and were careful about their expectations. This openness is probably an indication that HPs believe that acceptance of the culture and beliefs of patients and their families might positively affect response to treatment, whatever the burn size.

Il existe en Suisse une médecine traditionnelle dénommée « secret ¼ dédiée aux brûlures (supposée avoir des effets analgésiques et cicatrisants) inscrite au patrimoine immatériel de l'UNESCO depuis 2012. Dans la mesure où elle est très largement utilisée, nous avons conduit une étude observationnelle sur l'opinion qu'en ont les soignants et les patients du CTB national de Lausanne. Nous avons utilisé un questionnaire à dix items, développé après des entretiens plus informels. Trente six professionnels et 12 patients (ou parents quand le patient était mineur), interrogés après leur sortie, ont volontairement participé à l'étude. Tous les professionnels avaient entendu parler de « secret ¼ soit au travail soit chez eux (26). Trente trois étaient persuadés de son utilité analgésique, 1 seul le considérant comme dangereux. Cette opinion varie selon la catégorie professionnelle et l'expérience personnelle, les infirmières et aide- soignantes estimant qu'il devrait être plus largement utilisé. Les patients estimaient que « secret ¼ était un adjuvant ne devant pas remplacer la prise en charge médicalisée. Les professionnels considéraient que « secret ¼ est simple et utile. Les patients étaient intéressée par cette approche parallèle, tout en gardant une certaine retenue quant à ce qu'ils pouvaient en attendre. Cette ouverture d'esprit suggère que les professionnels pensent que la prise en compte de la culture et des croyances des patients et de leur famille peut promouvoir l'efficacité du traitement conventionnel, quelle que soit la surface brûlée.

Decellularised tissues obtained by a CO2-philic detergent and supercritical CO2.

Tissue decellularisation has gained much attention in regenerative medicine as an alternative to synthetic materials. In decellularised tissues, biological cues can be maintained and provide cellular environments still unmet by synthetic materials. Supercritical CO2 (scCO2 ) has recently emerged as a promising alternative decellularisation technique to aggressive detergents; in addition, scCO2 provides innate sterilisation. However, to date, decellularisation with scCO2 is limited to only a few tissue types with low cellular density. In the current study, a scCO2 technique to decellularise high density tissues, including articular cartilage, tendon and skin, was developed. Results showed that most of the cellular material was removed, while the sample structure and biocompatibility was preserved. The DNA content was reduced in cartilage, tendon and skin as compared to the native tissue. The treatment did not affect the initial tendon elastic modulus [reduced from 126.35 ± 9.79 MPa to 113.48 ± 8.48 MPa (p 〉 0.05)], while it reduced the cartilage one [from 12.06 ± 2.14 MPa to 1.17 ± 0.34 MPa (p 〈 0.0001)]. Interestingly, cell adhesion molecules such as fibronectin and laminin were still present in the tissues after decellularisation. Bovine chondrocytes were metabolically active and adhered to the surface of all decellularised tissues after 1 week of cell culture. The developed method has the potential to become a cost-effective, one-step procedure for the decellularisation of dense tissues.

Effect of temporal onsets of mechanical loading on bone formation inside a tissue engineering scaffold combined with cell therapy.

Several approaches to combine bone substitutes with biomolecules, cells or mechanical loading have been explored as an alternative to the limitation and risk-related bone auto- and allo-grafts. In particular, human bone progenitor cells seeded in porous poly(L-lactic acid)/tricalcium phosphate scaffolds have shown promising results. Furthermore, the application of mechanical loading has long been known to be a key player in the regulation of bone architecture and mechanical properties. Several in vivo studies have pointed out the importance of its temporal offset. When an early mechanical loading was applied a few days after scaffold implantation, it was ineffective on bone formation, whereas a delayed mechanical loading of several weeks was beneficial for bone tissue regeneration. No information is reported to date on the effectiveness of applying a mechanical loading in vivo on cell-seeded scaffold with respect to bone formation in a bone site. In our study, we were interested in human bone progenitor cells due to their low immunogenicity, sensitivity to mechanical loading and capacity to differentiate into osteogenic human bone progenitor cells. The latest capacity allowed us to test two different bone cell fates originating from the same cell type. Therefore, the general aim of this study was to assess the outcome on bone formation when human bone progenitor cells or pre-differentiated osteogenic human bone progenitor cells are combined with early and delayed mechanical loading inside bone tissue engineering scaffolds. Scaffolds without cells, named cell-free scaffold, were used as control. Surprisingly, we found that (1) the optimal solution for bone formation is the combination of cell-free scaffolds and delayed mechanical loading and that (2) the timing of the mechanical application is crucial and dependent on the cell type inside the implanted scaffolds.

Zone-dependent mechanical properties of human articular cartilage obtained by indentation measurements.

Emerging 3D printing technology permits innovative approaches to manufacture cartilage scaffolds associated with layer-by-layer mechanical property adaptation. However, information about gradients of mechanical properties in human articular cartilage is limited. In this study, we quantified a zone-dependent change of local elastic modulus of human femoral condyle cartilage by using an instrumented indentation technique. From the cartilage superficial zone towards the calcified layer, a gradient of elastic modulus values between 0.020 ± 0.003 MPa and 6.44 ± 1.02 MPa was measured. To validate the tissue quality, the histological tissue composition was visualized by glycosaminoglycan and collagen staining. This work aims to introduce a new protocol to investigate the zone-dependent mechanical properties of graded structures, such as human articular cartilage. From this knowledge, better cartilage repair strategies could be tailored in the future.

Stability Enhancement Using Hyaluronic Acid Gels for Delivery of Human Fetal Progenitor Tenocytes.

Tendon afflictions are very common, and their negative impact is high both at the workplace and in leisure activities. Tendinopathies are increasing in prevalence and can lead to tendon ruptures, where healing is a long process with outcomes that are often disappointing. Human fetal progenitor tenocytes (hFPTs) have been recently tested in vitro as a potential cell source to stimulate tendon regeneration. The aim of the present study was to compare different commercial hyaluronic acid (HA) gels, which could be used to resuspend hFPTs in a formulation that would allow for good delivery of the cells. No medium or growth supplement was used in the formulation in order to make it therapeutically dispensable. These conditions are stringent for cells, but surprisingly, we found that different formulations could allow a good survival for up to 3 days when stored at 4°C (refrigerator stable). The gels must allow a good survival of the cells in parallel with a good stability of the preparation over time and sufficient viscosity to remain in place if deposited on a wounded location. Moreover, the cells must conserve their ability to attach and to proliferate. hFPTs were able to survive and to recover from all of the tested gels, but some products showed some advantages over others in terms of survival and viscosity. Finally, the Ostenil Tendon HA gel fulfilled all of the requirements and presented the best compromise between a good survival and sufficient rheological characteristics to create an interesting cell delivery system.

Peptide-decorated chitosan derivatives enhance fibroblast adhesion and proliferation in wound healing.

RGD peptide sequences are known to regulate cellular activities by interacting with α5ß1, αvß5 and αvß3 integrin, which contributes to the wound healing process. In this study, RGDC peptide was immobilized onto chitosan derivative 1,6-diaminohexane-O-carboxymethyl-N,N,N-trimethyl chitosan (DAH-CMTMC) to display RGDC-promoting adhesion for enhanced wound healing. The efficiency of N-methylation, O-carboxymethylation and spacer grafting was quantitatively and qualitatively analyzed by (1)H NMR and FTIR, yielding 0.38 degree of substitution for N-methylation and >0.85 for O-carboxymethylation. The glass transition temperatures for chitosan derivatives were also studied. Peptide immobilization was achieved through sulfhydryl groups using sulfosuccinimidyl (4-iodoacetyl)amino-benzoate (sulfo-SIAB method). RGDC immobilized peptide onto DAH-CMTMC was found to be about 15.3 µg/mg of chitosan derivative by amino acid analysis (AAA). The significant increase of human dermal fibroblast (HDF) viability in vitro over 7 days suggests that RGDC-functionalized chitosan may lead to enhanced wound healing (viability >140%). Moreover, bio-adhesion and proliferation assays confirmed that coatings of RGDC-functionalized chitosan derivatives exhibit in vitro wound healing properties by enhancing fibroblast proliferation and adhesion. These results showed that RGDC peptide-functionalized chitosan provides an optimal environment for fibroblast adhesion and proliferation.

Human Fetal Progenitor Tenocytes for Regenerative Medicine.

Tendon injuries are very frequent and affect a wide and heterogeneous population. Unfortunately, the healing process is long with outcomes that are not often satisfactory due to fibrotic tissue appearance, which leads to scar and adhesion development. Tissue engineering and cell therapies emerge as interesting alternatives to classical treatments. In this study, we evaluated human fetal progenitor tenocytes (hFPTs) as a potential cell source for treatment of tendon afflictions, as fetal cells are known to promote healing in a scarless regenerative process. hFPTs presented a rapid and stable growth up to passage 9, allowing to create a large cell bank for off-the-shelf availability. hFPTs showed a strong tenogenic phenotype with an excellent stability, even when placed in conditions normally inducing cells to differentiate. The karyotype also indicated a good stability up to passage 12, which is far beyond that necessary for clinical application (passage 6). When placed in coculture, hFPTs had the capacity to stimulate human adult tenocytes (hATs), which are responsible for the deposition of a new extracellular matrix during tendon healing. Finally, it was possible to distribute cells in porous or gel scaffolds with an excellent survival, thus permitting a large variety of applications (from simple injections to grafts acting as filling material). All of these results are encouraging in the development of an off-the-shelf cell source capable of stimulating tendon regeneration for the treatment of tendon injuries.

Burn patient care lost in good manufacturing practices?

Application of cell therapies in burn care started in the early 80s in specialized hospital centers world-wide. Since 2007, cell therapies have been considered as "Advanced Therapy Medicinal Products" (ATMP), so classified by European Directives along with associated Regulations by the European Parliament. Consequently, regulatory changes have transformed the standard linear clinical care pathway into a more complex one. It is important to ensure the safety of cellular therapies used for burn patients and to standardize as much as possible the cell sources and products developed using cell culture procedures. However, we can definitely affirm that concentrating the bulk of energy and resources on the implementation of Good Manufacturing Practice (GMP) alone will have a major negative impact on the care of severely burned patients world-wide. Developing fully accredited infrastructures and training personnel (required by the new directives), along with obtaining approval for clinical trials to go ahead, can be a lengthy process.We discuss whether or not these patients could benefit from cell therapies provided by standard in-hospital laboratories, thus avoiding having to meet rigid regulations concerning the use of industrial pharmaceutical products. "Hospital Exemption" could be a preferred means to offer burn patients a customized and safe product, as many adaptations may be required throughout their treatment pathway. Patients who are in need of rapid treatment will be the ones to suffer the most from regulations intended to help them.

L'utilisation de la « thérapie cellulaire ¼ au profit des patients brûlés s'est mise en place au début des années 1980 dans de nombreux centres, répartis de par le monde. Depuis 2007, les produits utilisés ont fait l'objet de directives européennes. De ce fait, la prise en charge directe du patient est devenue un parcours semé d'embûches. S'il est important d'assurer au patient l'utilisation de produits dérivés de culture cellulaire de qualité, fabriqués selon des procédés reproductibles, il est évident que la mise en place dans les unités des « Bonnes Pratiques de Fabrication ¼ entraînera des dépenses de temps et d'énergie qui auront inévitablement un impact négatif sur la prise en charge du patient très gravement brûlé. En outre, la mise à niveau de l'infrastructure et la formation du personnel (exigées par les directives actuelles) ainsi que l'obtention des essais cliniques nécessaires à l'autorisation d'utilisation de ces produits peuvent s'avérer très longues. Nous argumentons la possibilité de fabriquer ces produits de culture cellulaire dans des laboratoires hospitaliers classiques en évitant la très lourde procédure destinée principalement à l'industrie pharmaceutique. Une « exemption hospitalière ¼ pourrait être un moyen d'offrir aux brûlés une thérapeutique adaptée et sécurisée, dans la mesure où des adaptations personnalisées peuvent être nécessaires au long de leur traitement. Les patients ayant un besoin vital d'un traitement urgent seront ceux qui pâtiront le plus d'une loi sensée les protéger.

How important is hydrotherapy? Effects of dynamic action of hot spring water as a rehabilitative treatment for burn patients in Switzerland.

Burn rehabilitation using hydrotherapy can have multiple benefits for the burn patient. The therapy uses specific mineral enriched hot spring water and water jets with varied hydro-pressure to combat hypertrophy, inflammatory reaction signs, abnormal pigmentation, and, more specifically, redness and scarring. Standard operating procedures for burn rehabilitation have been developed and integrated into the Standard of Care at the CHUV hospital using localized hydro-mechanical stimulation of burn sites (20 minutes of alternating anatomical sites) followed by constant pressure large-bore and filiform showers targeting specific scarred areas. These therapeutic regimens are repeated daily for 2 to 3 weeks. Patients showed lasting effects from this regimen (up to 3-6 months), the results becoming permanent with more uniform skin structure, color and visco-elasticity in addition to a decrease in pruritus. The specifications of clinical protocols are described herein along with the virtues of hot spring hydro-pressure therapy for burn rehabilitation. The use of hydrotherapy, which has been a controversial topic among burn units across the world, is also discussed. In North America, hydrotherapy is defined only within the scope of in-patient wound cleansing and is thought to lead to microbial auto-contamination and bacterial resistance. In Switzerland and France the emphasis of hydrotherapy is on rehabilitation after the wound has closed.

L'hydrothérapie pendant la réhabilitation des patients atteints de brûlures peut avoir plusieurs avantages. Le point focal de cette thérapie est l'utilisation d'une source d'eau thermale de source chaude enrichie en minéraux et de jets d'eau avec une variation de pression afin de lutter contre l'hypertrophie, les signes de réaction inflammatoire, une pigmentation anormale et en particulière des rougeurs et des cicatrices. Pour la réhabilitation des brûlures, les procédures d'utilisation normalisées ont été développés et intégrés dans le standard des soins dans notre hôpital. Ces procedures comportent une stimulation hydro-mécanique localisée sur les sites de brûlures (20 minutes en alternant les sites atomiques), suivie par une pression constante localisée directement sur les cicatrices faite à l'aide de douches de gros diamètre et puis de douches filiformes. Ce régime thérapeutique est répétée quotidiennement pendant 2 à 3 semaines. Après le traitement, les patients ont pu observer une structure plus uniforme de leur peau ainsi qu'une amélioration de sa couleur et de sa visco-élasticité, aussi bien que la diminution du prurit, et ce durant 3 à 6 mois. Ici nous présentons les spécificités de notre protocoles cliniques et les avantages d'une traitement d'eau thermale de source sous pression pour la réhabilitation des patients brûlés. Nous parlerons également de l'utilisation de l'hydrothérapie, qui est un sujet de controverse parmi les unités de soins aux brûlures à travers le monde. En Amérique du Nord, l'hydrothérapie est définie uniquement dans le cadre du nettoyage des plaies des patients hospitalisés, et elle peut conduire à l'auto-contamination microbienne et la résistance bactérienne. En Suisse et en France, l'hydrothérapie concerne uniquement la réhabilitation des plaies une fois cellesci fermées.