Detecting and distinguishing infrared radiation for non-invasive medical diagnostic purposes has been attempted for basic surface temperature assessment since the middle of the 20th century. However, the long wavelength and low energy of infrared radiation impede the detection of signals from deeper tissue layers, significantly limiting its use in diagnostics. To overcome these limitations, a novel approach was developed by combining a semiconductor gallium arsenide chip and prism-based optics that enabled the detection of signals in the infrared and terahertz spectrum. Challenges related to penetration depth and thermal noises were addressed by neural network modelling.

Preserved allogeneic donor skin still represents one of the gold standard therapies in temporary wound coverage in severely burned patients or chronic wounds. Allogeneic skin grafts are currently commercially available as cryo- or glycerol-preserved allografts through skin tissue banks all over the world. Most of the skin tissue banks rely on human cadaveric skin donations. Due to the chronic shortage of human allogeneic transplants, such as skin, and increasing costs in the procurement of allografts from other skin tissue banks, Hannover Medical School has been building up its own skin tissue bank based on allogeneic skin grafts from living donors who underwent surgical treatment (i.e., body-contouring procedures, such as abdominioplasties). This article presents procedures and protocols for the procurement and processing of allogeneic skin grafts according to national legislation and European regulations and guidelines. Beside protocols, initial microbiological data regarding the sterility of the harvested grafts are presented. The results currently form the basis for further investigations as well as clinical applications. In summary, a microbiological testing and acceptance procedure is presented that ensures adequate patient safety and skin viability.

Intraneural ganglia are benign mucinous cysts located within the epineurium of a peripheral nerve. The pathogenesis and formation of intraneural ganglia are controversial. The main theories described in the literature are of degenerative, synovial or de novo occurrence. We present the case of a 14-year-old boy who presented in our outpatient clinic with a complaint of interdigital neuralgia between hallux and second toe, as well as left foot drop. MRI examination showed a hyperintense cystic distension of the common peroneal nerve measuring 130 mm × 5 mm extending from the poplitea to the anterior compartment of the leg. We performed microscopic decompression and neurolysis surgery. The cyst showed a sac-like distension at its distal end with connection to the tibiofibular joint and was resected. After 8 weeks, postoperatively, the boy claimed to be pain-free and slight recovery of the superficial peroneal nerve was noticed. At 6 months postoperative, the patient showed a continuous improvement of motor function, demonstrating foot eversion with 3/5 muscle strength and foot extension with 2/5 muscle strength. Intraneural ganglia reported for pediatric patients represent a very rare entity. To the best of our knowledge, less than 15 cases have been described within the English-speaking literature.

Background Traumatic nerve injuries are associated with a high morbidity and long rehabilitation times. The extent of a nerve lesion and the related regeneration potential can often only be estimated during the course, whereby the time window for successful surgical interventions is limited. Objective The incidence and distribution of traumatic nerve lesions are reported. Algorithms for treatment decisions are presented. Material and methods Statistics from the German TraumaRegister DGU (R) as well as international registers were evaluated. The results of basic research and expert recommendations for diagnostics and treatment are discussed. Results and conclusion A strategic approach to conservative and surgical treatment of traumatic nerve injuries depending on the extent of injury and resulting regeneration potential is recommended. In conjunction with the clinical course, electrophysiology and imaging diagnostics, e.g. nerve sonography, can help to differentiate between neurapraxia, axonotmesis and neurotmesis.

Polytraumatisierte Brandverletzte stellen ein seltenes Patientenkollektiv dar und erfordern aufgrund der besonderen Kombinationsverletzung ein eigenes Behandlungskonzept. Vor dem Hintergrund dieses speziellen Verletzungsmusters stellt sich die Frage nach einem interdisziplinären Behandlungsalgorithmus, insbesondere wenn tiefgradige Verbrennungen über der Frakturzone lokalisiert sind. Grundlagen des vorliegenden Beitrags sind eine PubMed-basierte Literaturrecherche und eigene Erfahrungen eines universitären Traumazentrums für Schwerbrandverletzte mit Darstellung der besonderen therapeutischen Anforderungen und Zielsetzungen anhand eines Fallbeispiels. Die Auswertung der Literaturrecherche und eigener Behandlungsergebnisse kommt zu dem Ergebnis, dass Amputationen und Infektionen bei rechtzeitiger und interdisziplinärer Einbindung des plastischen Chirurgen durch frühe kombinierte Frakturstabilisierung, Nekrosektomie und sofortige Hauttransplantation in Häufigkeit und Ausmaß reduziert werden können. Plastisch-rekonstruktive Eingriffe ermöglichen zudem eine funktionelle und ästhetische Wiederherstellung mit optimierter Prothesenversorgung. Polytraumatisierte Schwerbrandverletzte erfordern einen interdisziplinären Behandlungsansatz, wobei Längenerhalt, Funktionalität und Ästhetik der betroffenen Extremitäten unter Vermeidung von Knochen- und Weichteilinfektionen oberstes Behandlungsprimat sind.

Traumatische Nervenverletzungen gehen mit einer hohen Morbidität und langen Rehabilitationszeiten einher. Das Ausmaß der Nervenschädigung mit dem damit verbundenen Regenerationspotenzial kann oft erst im Verlauf eingeschätzt werden, wobei das Zeitfenster für erfolgreiche chirurgische Interventionen begrenzt ist. Inzidenz und Verteilung traumatischer Nervenläsionen, Darstellung von Algorithmen zur Therapieentscheidung. Auswertung von Statistiken aus dem TraumaRegister DGU® sowie internationalen Registern. Diskussion von Grundlagenarbeiten und Expertenempfehlungen zu Diagnostik und Therapie. Ein strategisches Vorgehen bei der konservativen und operativen Behandlung von Nervenläsionen in Abhängigkeit vom Ausmaß der Schädigung und dem resultierenden Regenerationspotenzial ist empfohlen. In Zusammenschau mit dem klinischen Verlauf können elektrophysiologische und bildgebende Diagnostik wie die Nervensonographie helfen, zwischen Neurapraxie, Axonotmesis und Neurotmesis zu unterscheiden.

Noise is considered an artefact, in the practical use it is overcome by cool down the system in general at 77 K. We consider three biological examples which overcome noise by filtering the ratio between the signals and noise by using a distribution system. Noise is considered here in statistical terms poison, where the incident photon or otherwise in a detector and the detector has not influence and cannot increase.

The term “biomimetics” has evolved from technical achievements based on principles found in nature. Some of its general features are found in the four areas of plastic and reconstructive surgery: reconstruction, burns, hand and aesthetic surgery. A plastic surgeon mimics concepts of nature by transplanting tissue from one to the other side or rerouting tendons or muscles to another side in order to treat local or functional defects. In contrast, with biomimetics we try to implement principles and solutions from nature in order to form or create devices, materials or technical achievements which some of them can also help to restore human tissues, body parts or body functions. This article aims to highlight interfaces between biomimetic research and principles and practice of plastic surgery.

Background Polytraumatized burn patients represent a rare patient collective and necessitate an individualized treatment concept due to the particular combination of injuries. Objective Against the background of this special injury pattern, especially with deep burns overlying the fracture zone, the question of a specific and interdisciplinary treatment algorithm arises. Material and methods This article is based on a PubMed database search and experiences of a trauma center for severely injured burn patients at a university hospital, with presentation of the special therapeutic requirements and goals exemplified by a case report. Results The evaluation of the literature search and own treatment results comes to the conclusion that the rate and extent of amputations and infections can be reduced by an early and interdisciplinary involvement of the plastic surgeon by early combined fracture stabilization, excision of necrotic tissue and immediate skin grafting. Furthermore, plastic reconstructive procedures enable a functional and esthetic reconstruction with optimized prosthesis fitting. Conclusion Polytraumatized severely burned patients necessitate an interdisciplinary treatment approach, whereby preservation of length, functionality and esthetic appearance of the affected extremities and concurrent avoidance of bone and soft tissue infections have utmost priority.

Different families of snakes possess specialized infrared sensory organs which have evolved for thermoregulation as well as prey and predator detection. The sensor, a specialized “pore” found in the keratinized epidermal layer, is activated by infrared thermal radiation and transmits signals via the neuronal system through the trigeminal nerve. Here we present findings from anatomical and physiological studies of the infrared sensor of pit viper, python and boa using histology, optical coherence tomography, laser microdissection and capillary electrophoresis to identify and characterize a lipoprotein and its important role during sensor activation. Furthermore, the mechanism for signal detection and enhancement as well as reduction of background noise was simulated using neural network analysis based on the findings from histology. A high density of free nerve endings and multiple neural (i.e. dendrite) connections in the sensor organ are crucial for signal detection and processing and work as a filter to overcome background noise.

In the field of tissue engineering, spherical phosphorescent microprobes are well suited to quantify the oxygen content in close proximity to the cells during their growth phase. When using standard seed trays like glass dishes, probe excitation and signal acquisition can be realized by applying a fluorescence microscope. However, when using a bulky bioreactor a custom-built optics system with a laser as the excitation source had to be employed. Here we describe the basic principles of spherical optical oxygen microprobes for use in standard cell cultures and the system modifications with a laser, which were required in order to perform similar measurements from a distance in bioreactor cultures.

In the present study we tested magnetosomes isolated from the magnetic bacterium Magnetospirillum gryphiswaldense for their magnetic qualities when embedded in three different environmental surroundings: (1) medium (Phosphate buffer saline PBS), (2) gelatin gel matrix and as (3) powder. (3) is used as base line (standard control). We studied the magnetic hysteresis, thermal degradation in relation to theoretical results obtained with natural magnetosomes, by using an indirect analysis with biomimetic principles.

Human mesenchymal stem cells derived from adipose tissue (AD-hMSCs) represent a promising source for tissue engineering and are already widely used in cell therapeutic clinical trials. Until today, an efficient and sustainable cell labeling system for cell tracking does not exist. We evaluated transient transfection through electroporation for cell labeling and compared it with lentiviral transduction for AD-hMSCs. In addition, we tested whether nonsense DNA or a reporter gene such as enhanced green fluorescent protein (EGFP) is the more suitable label for AD-hMSCs. Using electroporation, the transfection efficiency reached a maximal level of 44.6 +/- 1.1% EGFP-positive cells after selective and expansive cultivation of the mixed MSC population, and was 44.5 +/- 1.4% after gene transfer with Cyanin3-marked nonsense-label DNA, which remained stable during 2 weeks of nonselective cultivation (37.2 +/- 4.7% positive AD-hMSCs). Electroporation with both nonsense DNA and pEGFP-N1 led to a slight growth retardation of 45.2% and 59.1%, respectively. EGFP-transfected or transduced AD-hMSCs showed a limited adipogenic and osteogenic differentiation capacity, whereas it was almost unaffected in cells electroporated with the nonsense-label DNA. The nonsense DNA was detectable through quantitative real-time polymerase chain reaction for at least 5 weeks/10 passages and in differentiated AD-hMSCs. EGFP-labeled cells were trackable for 24 h in vitro and served as testing cells with new materials for dental implants for 7 days. In contrast, lentivirally transduced AD-hMSCs showed an altered natural immune phenotype of the AD-hMSCs with lowered expression of two cell type defining surface markers (CD44 and CD73) and a relevantly decreased cell growth by 71.8% as assessed by the number of colony-forming units. We suggest electroporation with nonsense DNA as an efficient and long-lasting labeling method for AD-hMSCs with the comparably lowest negative impact on the phenotype or the differentiation capacity of the cells, which may, therefore, be suitable for tissue engineering. In contrast, EGFP transfection by electroporation is efficient but may be more suitable for cell tracking within cell therapies without MSC differentiation procedures. Since current protocols of lentiviral gene transduction include the risk of cell biological alterations, electroporation seems advantageous and sustainable enough for hMSC labeling.

A three-dimensional computational fluid dynamics-(CFD-) model based on a differential pressure laminar flow bioreactor prototype was developed to further examine performance under changing culture conditions. Cell growth inside scaffolds was simulated by decreasing intrinsic permeability values and led to pressure build-up in the upper culture chamber. Pressure release by an integrated bypass system allowed continuation of culture. The specific shape of the bioreactor culture vessel supported a homogenous flow profile and mass flux at the scaffold level at various scaffold permeabilities. Experimental data showed an increase in oxygen concentration measured inside a collagen scaffold seeded with human mesenchymal stem cells when cultured in the perfusion bioreactor after 24 h compared to static culture in a Petri dish (dynamic: 11% O-2 versus static: 3% O-2). Computational fluid simulation can support design of bioreactor systems for tissue engineering application.

We present a new method for noninvasive real-time oxygen measurement inside three-dimensional tissue-engineered cell constructs in static and dynamic culture settings in a laminar flow bioreactor. The OPAL system (optical oxygen measurement system) determines the oxygen-dependent phosphorescence lifetime of spherical microprobes and uses a two-frequency phase-modulation technique, which fades out the interference of background fluorescence from the cell carrier and culture medium. Higher cell densities in the centrum of the scaffolds correlated with lower values of oxygen concentration obtained with the OPAL system. When scaffolds were placed in the bioreactor, higher oxygen values were measured compared to statically cultured scaffolds in a Petri dish, which were significantly different at day 1-3 of culture. This technique allows the use of signal-weak microprobes in biological environments and monitors the culture process inside a bioreactor.

Tumor resection and trauma may leave devastating defects in the head and neck area complicating and preventing patient rehabilitation; therefore, plastic surgery methods are required which are able to prevent further complications and provide efficient functional and aesthetic reconstruction. In this review article typical cases and the interdisciplinary management of plastic surgery are presented.