Biocompatibility of Synechococcus sp. PCC 7002 with Human Dermal Cells In Vitro.

Being the green gold of the future, cyanobacteria have recently attracted considerable interest worldwide. This study investigates the adaptability and biocompatibility of the cyanobacterial strain Synechococcus sp. PCC 7002 with human dermal cells, focusing on its potential application in biomedical contexts. First, we investigated the adaptability of Synechococcus PCC 7002 bacteria to human cell culture conditions. Next, we evaluated the biocompatibility of cyanobacteria with common dermal cells, like 3T3 fibroblasts and HaCaT keratinocytes. Therefore, cells were directly and indirectly cocultured with the corresponding cells, and we measured metabolic activity (AlamarBlue assay) and proliferation (cell count and PicoGreen assay). The lactate dehydrogenase (LDH) assay was performed to determine the cytotoxic effect of cyanobacteria and their nutrition medium on human dermal cells. The cyanobacteria exhibited exponential growth under conventional human cell culture conditions, with the temperature and medium composition not affecting their viability. In addition, the effect of illumination on the proliferation capacity was investigated, showing a significant impact of light exposure on bacterial growth. The measured oxygen production under hypoxic conditions demonstrated a sufficient oxygen supply for further tissue engineering approaches depending on the number of bacteria. There were no significant adverse effects on human cell viability and growth under coculture conditions, whereas the LDH assay assessed signs of cytotoxicity regarding 3T3 fibroblasts after 2 days of coculturing. These negative effects were dismissed after 4 days. The findings highlight the potential of Synechococcus sp. PCC 7002 for integration into biomedical approaches. We found no cytotoxicity of cyanobacteria on 3T3 fibroblasts and HaCaT keratinocytes, thus paving the way for further in vivo studies to assess long-term effects and systemic reactions.

Artificial Intelligence in Dermatology Image Analysis: Current Developments and Future Trends.

BACKGROUND: Thanks to the rapid development of computer-based systems and deep-learning-based algorithms, artificial intelligence (AI) has long been integrated into the healthcare field. AI is also particularly helpful in image recognition, surgical assistance and basic research. Due to the unique nature of dermatology, AI-aided dermatological diagnosis based on image recognition has become a modern focus and future trend. Key scientific concepts of review: The use of 3D imaging systems allows clinicians to screen and label skin pigmented lesions and distributed disorders, which can provide an objective assessment and image documentation of lesion sites. Dermatoscopes combined with intelligent software help the dermatologist to easily correlate each close-up image with the corresponding marked lesion in the 3D body map. In addition, AI in the field of prosthetics can assist in the rehabilitation of patients and help to restore limb function after amputation in patients with skin tumors. THE AIM OF THE STUDY: For the benefit of patients, dermatologists have an obligation to explore the opportunities, risks and limitations of AI applications. This study focuses on the application of emerging AI in dermatology to aid clinical diagnosis and treatment, analyzes the current state of the field and summarizes its future trends and prospects so as to help dermatologists realize the impact of new technological innovations on traditional practices so that they can embrace and use AI-based medical approaches more quickly.

Nonsubjective Assessment of Shape, Volume and Symmetry during Breast Augmentation with Handheld 3D Device.

Three-dimensional Surface Imaging (3DSI) has become a valuable tool for planning and documenting surgical procedures. Although surface scanners have allowed for a better understanding of breast shape, size, and asymmetry during patient consultation, its use has not been included in intraoperative assessment so far. Validation of the reliability of the intraoperative use of a portable handheld 3DSI equipment as a tool to evaluate morphological changes during breast augmentation surgery. The patients who underwent bilateral subpectoral breast augmentation through an inframammary incision were included in this study. Intraoperative 3DSI was performed with the Artec Eva device, allowing for visualization of the surgical area before incision, after use of breast sizers and implant, and after wound closure. Intraoperatively manual measurements of breast distances and volume changes due to known sizer and implant volumes were in comparison with digital measurements calculated from 3DSI of the surgical area. Bilateral breasts of 40 patients were 3D photographed before incision and after suture successfully. A further 108 implant sizer uses were digitally documented. There was no significant difference between manual tape measurement and digital breast distance measurement. Pre- to postoperative 3D volume change showed no significant difference to the known sizer and implant volume.

Investigating the Reliability of Novel Nasal Anthropometry Using Advanced Three-Dimensional Digital Stereophotogrammetry.

Three-dimensional surface imaging systems (3DSI) provide an effective and applicable approach for the quantification of facial morphology. Several researchers have implemented 3D techniques for nasal anthropometry; however, they only included limited classic nasal facial landmarks and parameters. In our clinical routines, we have identified a considerable number of novel facial landmarks and nasal anthropometric parameters, which could be of great benefit to personalized rhinoplasty. Our aim is to verify their reliability, thus laying the foundation for the comprehensive application of 3DSI in personalized rhinoplasty. We determined 46 facial landmarks and 57 anthropometric parameters. A total of 110 volunteers were recruited, and the intra-assessor, inter-assessor, and intra-method reliability of nasal anthropometry were assessed through 3DSI. Our results displayed the high intra-assessor reliability of MAD (0.012-0.29, 0.003-0.758 mm), REM (0.008-1.958%), TEM (0-0.06), rTEM (0.001-0.155%), and ICC (0.77-0.995); inter-assessor reliability of 0.216-1.476, 0.003-2.013 mm; 0.01-7.552%, 0-0.161, and 0.001-1.481%, 0.732-0.985, respectively; and intra-method reliability of 0.006-0.598°, 0-0.379 mm; 0 0.984%, 0-0.047, and 0-0.078%, 0.996-0.998, respectively. This study provides conclusive evidence for the high reliability of novel facial landmarks and anthropometric parameters for comprehensive nasal measurements using the 3DSI system. Considering this, the proposed landmarks and parameters could be widely used for digital planning and evaluation in personalized rhinoplasty, otorhinolaryngology, and oral and maxillofacial surgery.

Reproducibility of Novel Soft-Tissue Landmarks on Three-Dimensional Human Facial Scan Images in Caucasian and Asian.

BACKGROUND: Three-dimensional surface imaging is established in many disciplines for objective facial acquisition regarding anthropometry. Former studies addressed the validation of landmark-based measurements for single race. In order to distinguish racial difference, the reproducibility of the landmark measurements must first be validated. OBJECTIVES: Our purpose is to validate the reproducibility of 46 facial soft-tissue landmarks on x, y, z axes to prove their reliability as 3D reference points. METHODS: The study included 80 European Caucasian and 80 Chinese volunteers. Standardized 3D surface imaging was performed using Vectra 3D system. Two raters identified and defined 46 landmarks (138 coordinates), then repeatedly 3D-imaged volunteers' facial region in separate sessions. Coordinates' reproducibility of landmarks is divided into three categories (< 0.5 mm, < 1 mm, and >1 mm) for intra- and inter-rater reproducibility assessments. RESULTS: Coordinates' reproducibility of 160 samples was distributed as follows: Intra-rater: < 0.5 mm (45%), < 1 mm (42%), >1 mm (13%); inter-rater: < 0.5 mm (31.2%), < 1 mm (42%), > 1 mm (26.8%). The reproducibility of landmarks in nasal tip region differs slightly between Caucasians and Asians. Compared to females, males typically have higher landmark reproducibility in lip and chin region. However, there were no differences in the reproducibility ranking of landmarks by gender. CONCLUSION: The majority of the 46 landmarks in the 3D plane are reproducible to 1 mm, which is clinically acceptable. All selected landmarks showed strong consistency across race and gender, suggesting their potential use as reference points in prospective clinical practice. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

[The frequency of performing vascular anastomoses determines the learning curve in a retrospective analysis of 212 participants of the Munich course of microsurgery]. / Die Häufigkeit der Durchführung einer Gefäßanastomose ist der entscheidende Faktor auf den Lernerfolg in einer retrospektiven Analyse von 212 Teilnehmern des Münchner Mikrochirurgiekurses.

OBJECTIVE: Microsurgical courses are a widely accepted and common method of acquiring microsurgical skills outside of the operation theatre. In-vivo models are often used to prepare surgeons for vascular microsurgery in patients. Although microsurgical courses are commonly offered and attended, the learning curve acquired in such courses remains elusive. MATERIAL AND METHODS: The patency of end-to-end anastomoses performed by a total of 212 participants with different education levels and from different specialist fields were assessed in models of living rats. Participants attended the annually held microsurgical course at the Department for Hand, Plastic and Aesthetic Surgery, Ludwig Maximilian University of Munich, between 2013 and 2018. RESULTS: A highly significant correlation (rp = 0,658; p < 0,001) between number of trials and patent anastomoses was observed. There was no significant correlation between years of surgical experience and age and total number of patent anastomoses achieved during the course. No statistically significant difference of total number of patent anastomoses between residents and board-certified surgeons was detected. CONCLUSION: Looking at the steep learning curves of our participants and the high rate of patent anastomoses, we recommend the setting of microsurgical courses using in-vivo models to overcome potential failures in the beginning of vascular microsurgery careers.

Experimental approach to nasal septal cartilage regeneration with adipose tissue-derived stem cells and decellularized porcine septal cartilage.

BACKGROUND: Cartilage shortage is a major problem in facial reconstructive surgery. Prior studies have shown that decellularized porcine nasal septal cartilage (DPNC) seeded with primary human nasal chondrocytes enabled cartilage regeneration and showed potential as a replacement material for nasal cartilage. Since adipose tissue-derived stem cells (ASCs) are easily accessible and almost abundantly available, they appear to be a promising alternative to limited chondrocytes making the combination of DPNC and ASCs a feasible approach towards clinical translation. Thus, this study was intended to investigate the interactions between ASCs and DPNC in an in vitro model. METHODS: DPNCs were seeded and 3D-cultured with primary human ASCs that were priorly characterized with trilineage differentiation and flow cytometry. Cell vitality and proliferation were evaluated by Live-Dead, alamarBlue, and PicoGreen assays. Chondrogenic differentiation was examined by DMMB assay and cryosectioning-based histology. Cell invasion within DPNC was visualized and quantified by fluorescent histology (DAPI, Phalloidin). RESULTS: ASCs showed good adherence to DPNC and Live-Dead assay proved their viability over 2 weeks. AlamarBlueassay showed an increase in metabolic activity compared to 2D cultures, and PicoGreen assay demonstrated an increase of cell number within DPNC over time. Biochemical assays and histology added evidence of chondrogenic differentiation of 3D-cultured ASCs under the influence of chondrogenic induction medium. Fluorescent image analysis showed a significant increase of cell-occupied areas of scaffolds over time (P < .05). CONCLUSIONS: DPNC scaffolds provided a suitable environment for ASCs that allowed good cell vitality, high proliferation, and chondrogenic differentiation. Thus, the use of ASCs and DPNC yields a promising alternative to the use of primary human chondrocytes. For facial cartilage tissue engineering, we regard ASCs as an attractive alternative to human nasal chondrocytes due to their better accessibility and availability. Further research will be necessary to determine long-term effects and in vivo outcomes of ASCs and DPNC in cartilage regeneration of the face.

[Current review of factors in the stem cell donor that influence the regenerative potential of adipose tissue-derived stem cells]. / Eine aktuelle Übersicht über die Einflussfaktoren der Stammzellspender auf das regenerative Potential von Fettgewebsstammzellen.

BACKGROUND: Regenerative therapies like cell-assisted lipotransfer or preclinical experimental studies use adipose tissue-derived stem cells (ASCs) as the main therapeutic agent. But there are also factors depending on the clinical donor that influence the cell yield and regenerative potential of human ASCs and stromal vascular fraction (SVF). Therefore, the aim of this review was to identify and evaluate these factors according to current literature. METHODS: For this purpose, a systematic literature review was performed with focus on factors affecting the regenerative potential of ASCs and SVF using the National Library of Medicine. RESULTS: Currently, there is an abundance of studies regarding clinical donor factors influencing ASCs properties. But there is some contradiction and need for further investigation. Nevertheless, we identified several recurrent factors: age, sex, weight, diabetes, lipoedema, use of antidepressants, anti-hormonal therapy and chemotherapy. CONCLUSION: We recommend characterisation of the ASC donor cohort in all publications, regardless of whether they are experimental studies or clinical trials. By these means, donor factors that influence experimental or clinical findings can be made transparent and results are more comparable. Moreover, this knowledge can be used for study design to form a homogenous donor cohort by precise clinical history and physical examination.

Three-dimensional surface imaging in breast cancer: a new tool for clinical studies?

BACKGROUND: Three-dimensional Surface Imaging (3DSI) is a well-established method to objectively monitor morphological changes in the female breast in the field of plastic surgery. In contrast, in radiation oncology we are still missing effective tools, which can objectively and reproducibly assess and document adverse events in breast cancer radiotherapy within the framework of clinical studies. The aim of the present study was to apply structured-light technology as a non-invasive and objective approach for the documentation of cosmetic outcome and early effects of breast radiotherapy as a proof of principle. METHODS: Weekly 3DSI images of patients receiving either conventionally fractionated radiation treatment (CF-RT) or hypofractionated radiation treatment (HF-RT) were acquired during the radiotherapy treatment and clinical follow-up. The portable Artec Eva scanner (Artec 3D Inc., Luxembourg) recorded 3D surface images for the analysis of breast volumes and changes in skin appearance. Statistical analysis compared the impact of the two different fractionation regimens and the differences between the treated and the contralateral healthy breast. RESULTS: Overall, 38 patients and a total of 214 breast imaging sessions were analysed. Patients receiving CF-RT showed a significantly higher frequency of breast erythema compared to HF-RT (93.3% versus 34.8%, p = 0.003) during all observed imaging sessions. Moreover, we found a statistically significant (p < 0.05) volumetric increase of the treated breast of the entire cohort between baseline (379 ± 196 mL) and follow-up imaging at 3 months (437 ± 224 mL), as well as from week 3 of radiotherapy (391 ± 198 mL) to follow-up imaging. In both subgroups of patients undergoing either CF-RT or HF-RT, there was a statistically significant increase (p < 0.05) in breast volumes between baseline and 3 months follow-up. There were no statistically significant skin or volumetric changes of the untreated healthy breasts. CONCLUSIONS: This is the first study utilizing 3D structured-light technology as a non-invasive and objective approach for the documentation of patients receiving breast radiotherapy. 3DSI offers potential as a non-invasive tool to objectively and precisely monitor the female breast in a radiooncological setting, allowing clinicians to objectively distinguish outcomes of different therapy modalities.

Validation of two handheld devices against a non-portable three-dimensional surface scanner and assessment of potential use for intraoperative facial imaging.

BACKGROUND: The aim of this study was to compare accuracy and timing of two handheld, mobile three-dimensional surface imaging (3DSI) devices against an established non-portable medical imaging system, and to evaluate future intraoperative use for facial surgery. METHODS: Surface-to-Surface root mean square analysis was used to evaluate both a consumer device (Sense 3D) and a professional surface scanner (Artec Eva) against a reference imaging system (Vectra XT). Two assessors repeatedly 3D-imaged the facial region of an imaging phantom and 30 volunteers in two separate sessions. Using both mobile devices, intraoperative 3DSI of 10 rhinoplasty patients was compared with preoperative reference imaging. Intraclass Correlation Coefficient was calculated for repeated measurements. RESULTS: Artec Eva yielded mean deviations below 0.5 mm for the whole face and all subunits excluding the eye region. Sense 3D showed similar deviations for the whole face, but otherwise only in the central and lateral forehead unit and the medial cheek. Variability was low for both the non-portable Vectra XT and Artec Eva, whereas full-face assessment using Sense 3D resulted in high variability. When compared to the preoperative reference images, intraoperative rhinoplasty 3DSI revealed low deviations for Artec Eva and high deviations for Sense 3D. CONCLUSIONS: The 3D surfaces captured by Artec Eva showed a similarly desirable accuracy for facial imaging as Vectra XT reference images. This handheld device presents a suitable option for the objective documentation during rhinoplasty surgery. Sense 3D was unable to accurately capture complex facial surfaces and is therefore limited in its usefulness for intraoperative 3DSI.

[Whole-body surface assessment - implementation and experiences with 360° 3D whole-body scans: opportunities to objectively monitor the extremities and the body trunk]. / Whole Body Surface Assessment ­ Implementierung und Erfahrungen von 360° 3D Ganzkörperscans: Möglichkeiten zur Objektivierung und Verlaufskontrolle an den Extremitäten und am Körperstamm.

BACKGROUND: Three-dimensional surface imaging (3DSI) has proven to be useful in providing objective aid to the planning process and documentation of various plastic-surgical procedures. Although this technology is routinely used in the surface and volume analysis of the face and breast, it has been of limited use in registering and quantifying the resulting changes to the entire body surface. The aim of this study was the clinical implementation of 360° whole-body scans to evaluate the treatment of lipoedema. PATIENTS, MATERIALS AND METHODS: Three 3DSI devices (Eva, Thor and Sense) were tested for precision and reproducibility regarding whole-body scans. Using a standardised setup consisting of an automatic turntable and predetermined body poses, human subjects were analysed by measuring axial circumferences and quantifying defined layers of body volume. The relevant statistical and clinical deviations were subsequently evaluated. RESULTS: A standardised procedure for 360° scans was successfully implemented. All tested scanners yielded sufficient results with respect to intraindividual reproducibility (p > 0.05). The Eva and Thor scanners delivered comparable results for axial circumference and volume analysis (p > 0.05). The Sense scanner allowed for a precise analysis in the area of the body trunk, but had significant deficits regarding the lower extremity (p < 0.05). The data analysis was then successfully applied to selected clinical cases. CONCLUSION: A procedure to reproducibly capture and analyse the human body was successfully established for clinical use in plastic surgery. Two of the tested 3DSI devices allowed for an objective surface and volume analysis of the human body. The third scanner (Sense) offered the ability to perform 360° scans at a low cost, albeit lacking in precision when applied to certain areas of the body. These findings may help to objectively evaluate the effects of different procedures on the entirety of the body surface in the future.

Towards autotrophic tissue engineering: Photosynthetic gene therapy for regeneration.

The use of artificial tissues in regenerative medicine is limited due to hypoxia. As a strategy to overcome this drawback, we have shown that photosynthetic biomaterials can produce and provide oxygen independently of blood perfusion by generating chimeric animal-plant tissues during dermal regeneration. In this work, we demonstrate the safety and efficacy of photosynthetic biomaterials in vivo after engraftment in a fully immunocompetent mouse skin defect model. Further, we show that it is also possible to genetically engineer such photosynthetic scaffolds to deliver other key molecules in addition to oxygen. As a proof-of-concept, biomaterials were loaded with gene modified microalgae expressing the angiogenic recombinant protein VEGF. Survival of the algae, growth factor delivery and regenerative potential were evaluated in vitro and in vivo. This work proposes the use of photosynthetic gene therapy in regenerative medicine and provides scientific evidence for the use of engineered microalgae as an alternative to deliver recombinant molecules for gene therapy.

Photosynthetic biomaterials: a pathway towards autotrophic tissue engineering.

Engineered tissues are highly limited by poor vascularization in vivo, leading to hypoxia. In order to overcome this challenge, we propose the use of photosynthetic biomaterials to provide oxygen. Since photosynthesis is the original source of oxygen for living organisms, we suggest that this could be a novel approach to provide a constant source of oxygen supply independently of blood perfusion. In this study we demonstrate that bioartificial scaffolds can be loaded with a solution containing the photosynthetic microalgae Chlamydomonas reinhardtii, showing high biocompatibility and photosynthetic activity in vitro. Furthermore, when photosynthetic biomaterials were engrafted in a mouse full skin defect, we observed that the presence of the microalgae did not trigger a native immune response in the host. Moreover, the analyses showed that the algae survived for at least 5 days in vivo, generating chimeric tissues comprised of algae and murine cells. The results of this study represent a crucial step towards the establishment of autotrophic tissue engineering approaches and suggest the use of photosynthetic cells to treat a broad spectrum of hypoxic conditions.

Surgical sutures filled with adipose-derived stem cells promote wound healing.

Delayed wound healing and scar formation are among the most frequent complications after surgical interventions. Although biodegradable surgical sutures present an excellent drug delivery opportunity, their primary function is tissue fixation. Mesenchymal stem cells (MSC) act as trophic mediators and are successful in activating biomaterials. Here biodegradable sutures were filled with adipose-derived mesenchymal stem cells (ASC) to provide a pro-regenerative environment at the injured site. Results showed that after filling, ASCs attach to the suture material, distribute equally throughout the filaments, and remain viable in the suture. Among a broad panel of cytokines, cell-filled sutures constantly release vascular endothelial growth factor to supernatants. Such conditioned media was evaluated in an in vitro wound healing assay and showed a significant decrease in the open wound area compared to controls. After suturing in an ex vivo wound model, cells remained in the suture and maintained their metabolic activity. Furthermore, cell-filled sutures can be cryopreserved without losing their viability. This study presents an innovative approach to equip surgical sutures with pro-regenerative features and allows the treatment and fixation of wounds in one step, therefore representing a promising tool to promote wound healing after injury.

Development of photosynthetic biomaterials for in vitro tissue engineering.

Tissue engineering has opened a new therapeutic avenue that promises a revolution in regenerative medicine. To date, however, the translation of engineered tissues into clinical settings has been highly limited and the clinical results are often disappointing. Despite decades of research, the appropriate delivery of oxygen into three-dimensional cultures still remains one of the biggest unresolved problems for in vitro tissue engineering. In this work, we propose an alternative source of oxygen delivery by introducing photosynthetic scaffolds. Here we demonstrate that the unicellular and photosynthetic microalga Chlamydomonas reinhardtii can be cultured in scaffolds for tissue repair; this microalga shows high biocompatibility and photosynthetic activity. Moreover, Chlamydomonas can be co-cultured with fibroblasts, decreasing the hypoxic response under low oxygen culture conditions. Finally, results showed that photosynthetic scaffolds are capable of producing enough oxygen to be independent of external supply in vitro. The results of this study represent the first step towards engineering photosynthetic autotrophic tissues.

Cell-based resorption assays for bone graft substitutes.

The clinical utilization of resorbable bone substitutes has been growing rapidly during the last decade, creating a rising demand for new resorbable biomaterials. An ideal resorbable bone substitute should not only function as a load-bearing material but also integrate into the local bone remodeling process. This means that these bone substitutes need to undergo controlled resorption and then be replaced by newly formed bone structures. Thus the assessment of resorbability is an important first step in predicting the in vivo clinical function of bone substitute biomaterials. Compared with in vivo assays, cell-based assays are relatively easy, reproducible, inexpensive and do not involve the suffering of animals. Moreover, the discovery of RANKL and M-CSF for osteoclastic differentiation has made the differentiation and cultivation of human osteoclasts possible and, as a result, human cell-based bone substitute resorption assays have been developed. In addition, the evolution of microscopy technology allows advanced analyses of the resorption pits on biomaterials. The aim of the current review is to give a concise update on in vitro cell-based resorption assays for analyzing bone substitute resorption. For this purpose models using different cells from different species are compared. Several popular two-dimensional and three-dimensional optical methods used for resorption assays are described. The limitations and advantages of the current ISO degradation assay in comparison with cell-based assays are discussed.

Vaginal carcinoma in a female-to-male transsexual.

INTRODUCTION: Sex reassignment surgery (SRS) can be considered a reasonable and secure treatment for transsexualism, today. Because the population of patients who have received SRS is growing steadily, it can be expected that the number of patients who present with diseases specific to their original gender will increase as well. AIM: In female-to-male transsexuals, vaginal cancer has not been reported so far. This article reports, to our knowledge, the first case of a female-to-male transsexual who developed vaginal cancer. METHODS: Eighteen years after receiving female-to-male SRS, the patient presented with vaginal cancer, which infiltrated rectum and bladder and also showed involvement of inguinal lymph nodes. Surgery consisted of an anterior and posterior pelvic demolition and extended lymphadenectomy with preservation of the penoid and reconstruction of the pelvic defect with multiple flaps. RESULTS: The tumor was removed completely (R0), and 2 years after surgery, the patient has no signs or symptoms of tumor recurrence and enjoys good quality of life. CONCLUSIONS: In SRS patients, diseases of their original gender should always be considered and patients should be encouraged to participate in screening programs. When choosing the surgical approach for SRS, the risks for developing cancer from remaining structures of the genetic gender should be considered. Of course, removal of e.g., ovaries, cervix and vagina, will prevent cancer of these structures. When it comes to surgery in SRS patients with malignancies, an interdisciplinary approach should be chosen.