Collagen fibrillar structures in vocal fold scarring and repair using stem cell therapy: a detailed histological, immunohistochemical and atomic force microscopy study.

Regenerative medicine opens new opportunities in the repair of cicatricial lesions of the vocal folds. Here, we present a thorough morphological study, with the focus on the collagen structures in the mucosa of the vocal folds, dedicated to the effects of stem cells on the vocal folds repair after cicatricial lesions. We used a conventional experimental model of a mature scar of the rabbit vocal folds, which was surgically excised with a simultaneous implantation of autologous bone marrow-derived mesenchymal stem cells (MSC) into the defect. The restoration of the vocal folds was studied 3 months postimplantation of stem cells and 6 months after the first surgery. The collagen structure assessment included histology, immunohistochemistry and atomic force microscopy (AFM) studies. According to the data of optical microscopy and AFM, as well as to immunohistochemical analysis, MSC implantation into the vocal fold defect leads not only to the general reduction of scarring, normal ratio of collagens type I and type III, but also to a more complete restoration of architecture and ultrastructure of collagen fibres in the mucosa, as compared to the control. The collagen structures in the scar tissue in the vocal folds with implanted MSC are more similar to those in the normal mucosa of the vocal folds than to those of the untreated scars. AFM has proven to be an instrumental technique in the assessment of the ultrastructure restoration in such studies. LAY DESCRIPTION: Regenerative medicine opens new opportunities in the repair of the vocal fold scars. Because collagen is a main component in the vocal fold mucosa responsible for the scar formation and repair, we focus on the collagen structures in the mucosa of the vocal folds, using a thorough morphological study based on histology and atomic force microscopy (AFM). Atomic force microscopy is a scanning microscopic technique which allows revealing the internal structure of a tissue with a resolution up to nanometres. We used a conventional experimental model of a mature scar of the rabbit vocal folds, surgically excised and treated with a mesenchymal stem cells transplant. Our morphological study, primarily AFM, explicitly shows that the collagen structures in the scarred vocal folds almost completely restore after the stem cell treatment. Thus, the modern microscopic methods, and especially AFM are instrumental tools for monitoring the repair of the vocal folds scars.

From Aggregates to Porous Three-Dimensional Scaffolds through a Mechanochemical Approach to Design Photosensitive Chitosan Derivatives.

The crustacean processing industry produces large quantities of waste by-products (up to 70%). Such wastes could be used as raw materials for producing chitosan, a polysaccharide with a unique set of biochemical properties. However, the preparation methods and the long-term stability of chitosan-based products limit their application in biomedicine. In this study, different scale structures, such as aggregates, photo-crosslinked films, and 3D scaffolds based on mechanochemically-modified chitosan derivatives, were successfully formed. Dynamic light scattering revealed that aggregation of chitosan derivatives becomes more pronounced with an increase in the number of hydrophobic substituents. Although the results of the mechanical testing revealed that the plasticity of photo-crosslinked films was 5⁻8% higher than that for the initial chitosan films, their tensile strength remained unchanged. Different types of polymer scaffolds, such as flexible and porous ones, were developed by laser stereolithography. In vivo studies of the formed structures showed no dystrophic and necrobiotic changes, which proves their biocompatibility. Moreover, the wavelet analysis was used to show that the areas of chitosan film degradation were periodic. Comparing the results of the wavelet analysis and X-ray diffraction data, we have concluded that degradation occurs within less ordered amorphous regions in the polymer bulk.

3D reconstruction of CT scans aid in preoperative planning for sarcomatoid renal cancer: A case report and mini-review.

Contrast-enhanced multi-slice computed tomography (MSCT) is commonly used in the diagnosis of complex malignant tumours. This technology provides comprehensive and accurate information about tumour size and shape in relation to solid tumours and the affected adjacent organs and tissues. This case report demonstrates the benefit of using MSCT 3D imaging for preoperative planning in a patient with late-stage (T4) sarcomatoid renal cell carcinoma, a rare renal malignant tumour. The surgical margin on the liver was negative, and no metastases to veins, lungs or other organs were detected by abdominal and chest contrast-enhanced CT. Although sarcomatoid histology is considered to be a poor prognostic factor, the patient is alive and well 17 months after surgery. The MSCT imaging modality enables 3D rendering of an area of interest, which assists surgical decision-making in cases of advanced renal tumours. In this case, as a result of MSCT 3D reconstruction, the patient received justified surgical treatment without compromising oncological principles.

Liquid Biopsy in Diagnosis and Prognosis of Non-Metastatic Prostate Cancer.

Currently, sensitive and specific methods for the detection and prognosis of early stage PCa are lacking. To establish the diagnosis and further identify an appropriate treatment strategy, prostate specific antigen (PSA) blood test followed by tissue biopsy have to be performed. The combination of tests is justified by the lack of a highly sensitive, specific, and safe single test. Tissue biopsy is specific but invasive and may have severe side effects, and therefore is inappropriate for screening of the disease. At the same time, the PSA blood test, which is conventionally used for PCa screening, has low specificity and may be elevated in the case of noncancerous prostate tumors and inflammatory conditions, including benign prostatic hyperplasia and prostatitis. Thus, diverse techniques of liquid biopsy have been investigated to supplement or replace the existing tests of prostate cancer early diagnosis and prognostics. Here, we provide a review on the advances in diagnosis and prognostics of non-metastatic prostate cancer by means of various biomarkers extracted via liquid biopsy, including circulating tumor cells, exosomal miRNAs, and circulating DNAs.

Isolation of Circulating Tumor Cells from Seminal Fluid of Patients with Prostate Cancer Using Inertial Microfluidics.

Prostate cancer (PCa) diagnosis is primarily based on prostate-specific antigen (PSA) testing and prostate tissue biopsies. However, PSA testing has relatively low specificity, while tissue biopsies are highly invasive and have relatively low sensitivity at early stages of PCa. As an alternative, we developed a technique of liquid biopsy, based on isolation of circulating tumor cells (CTCs) from seminal fluid (SF). The recovery of PCa cells from SF was demonstrated using PCa cell lines, achieving an efficiency and throughput as high as 89% (±3.8%) and 1.7 mL min-1, respectively, while 99% (±0.7%) of sperm cells were disposed of. The introduced approach was further tested in a clinical setting by collecting and processing SF samples of PCa patients. The yield of isolated CTCs measured as high as 613 cells per SF sample in comparison with that of 6 cells from SF of healthy donors, holding significant promise for PCa diagnosis. The correlation analysis of the isolated CTC numbers with the standard prognostic parameters such as Gleason score and PSA serum level showed correlation coefficient values at 0.40 and 0.73, respectively. Taken together, our results show promise in the developed liquid biopsy technique to augment the existing diagnosis and prognosis of PCa.

Mechanical properties of cell sheets and spheroids: the link between single cells and complex tissues.

Cell aggregates, including sheets and spheroids, represent a simple yet powerful model system to study both biochemical and biophysical intercellular interactions. However, it is becoming evident that, although the mechanical properties and behavior of multicellular structures share some similarities with individual cells, yet distinct differences are observed in some principal aspects. The description of mechanical phenomena at the level of multicellular model systems is a necessary step for understanding tissue mechanics and its fundamental principles in health and disease. Both cell sheets and spheroids are used in tissue engineering, and the modulation of mechanical properties of cell constructs is a promising tool for regenerative medicine. Here, we review the data on mechanical characterization of cell sheets and spheroids, focusing both on advances in the measurement techniques and current understanding of the subject. The reviewed material suggest that interplay between the ECM, intercellular junctions, and cellular contractility determines the behavior and mechanical properties of the cell aggregates.

Terahertz radiation and the skin: a review.

SIGNIFICANCE: Terahertz (THz) radiation has demonstrated a great potential in biomedical applications over the past three decades, mainly due to its non-invasive and label-free nature. Among all biological specimens, skin tissue is an optimal sample for the application of THz-based methods because it allows for overcoming some intrinsic limitations of the technique, such as a small penetration depth (0.1 to 0.3 mm for the skin, on average). AIM: We summarize the modern research results achieved when THz technology was applied to the skin, considering applications in both imaging/detection and treatment/modulation of the skin constituents. APPROACH: We perform a review of literature and analyze the recent research achievements in THz applications for skin diagnosis and investigation. RESULTS: The reviewed results demonstrate the possibilities of THz spectroscopy and imaging, both pulsed and continuous, for diagnosis of skin melanoma and non-melanoma cancer, dysplasia, scars, and diabetic condition, mainly based on the analysis of THz optical properties. The possibility of modulating cell activity and treatment of various diseases by THz-wave exposure is shown as well. CONCLUSIONS: The rapid development of THz technologies and the obtained research results for skin tissue highlight the potential of THz waves as a research and therapeutic instrument. The perspectives on the use of THz radiation are related to both non-invasive diagnostics and stimulation and control of different processes in a living skin tissue for regeneration and cancer treatment.

Battling Neurodegenerative Diseases with Adeno-Associated Virus-Based Approaches.

Neurodegenerative diseases (NDDs) are most commonly found in adults and remain essentially incurable. Gene therapy using AAV vectors is a rapidly-growing field of experimental medicine that holds promise for the treatment of NDDs. To date, the delivery of a therapeutic gene into target cells via AAV represents a major obstacle in the field. Ideally, transgenes should be delivered into the target cells specifically and efficiently, while promiscuous or off-target gene delivery should be minimized to avoid toxicity. In the pursuit of an ideal vehicle for NDD gene therapy, a broad variety of vector systems have been explored. Here we specifically outline the advantages of adeno-associated virus (AAV)-based vector systems for NDD therapy application. In contrast to many reviews on NDDs that can be found in the literature, this review is rather focused on AAV vector selection and their preclinical testing in experimental and preclinical NDD models. Preclinical and in vitro data reveal the strong potential of AAV for NDD-related diagnostics and therapeutic strategies.

Tissue engineering using a combined cell sheet technology and scaffolding approach.

Cell sheet technology has remained quite popular among tissue engineering techniques over the last several years. Meanwhile, there is an apparent trend in modern scientific research towards combining different approaches and strategies. Accordingly, a large body of work has arisen where cell sheets are used not as separate structures, but in combination with scaffolds as supporting constructions. The aim of this review is to analyze the intersection of these two vast areas of tissue engineering described in the literature mainly within the last five years. Some practical and technical details are emphasized to provide information that can be useful in research design and planning. The first part of the paper describes the general issues concerning the use of combined technology, its advantages and limitations in comparison with those of other tissue engineering approaches. Next, the detailed literature analysis of in vivo studies aimed at the regeneration of different tissues is performed. A significant part of this section concerns bone regeneration. In addition to that, other connective tissue structures, including articular cartilage and fibrocartilage, ligaments and tendons, and some soft tissues are discussed. STATEMENT OF SIGNIFICANCE: This paper describes the intersection of two technologies used in designing of tissue-engineered constructions for regenerative medicine: cell sheets as extracellular matrix-rich structures and supporting scaffolds as essentials in tissue engineering. A large number of reviews are devoted to each of these scientific problems. However, the solution of complex problems of tissue engineering requires an integrated approach that includes both three-dimensional scaffolds and cell sheets. This manuscript serves as a description of advantages and limitations of this method, its use in regeneration of bones, connective tissues and soft tissues and some other details.

Near-infrared fluorescence with indocyanine green for diagnostics in urology: initial experience.

INTRODUCTION: Fluorescence imaging with indocyanine green is used in urology for the detection of sentinel lymph nodes and identification of prostate margins in radical prostatectomy for delineation of resection zone and selective clamping of vessels in partial nephrectomy; for identification and evaluation of length of ureteral strictures; for assessment of perfusion and viability of anastomoses during reconstructive stage of cystectomy. Safety of this technique is proven, while its diagnostic value and usefulness is still controversial. METHODS: This pilot study of using the SPY Elite Fluorescence Imaging System for diagnostics was performed in the I.M. Sechenov First Moscow State Medical University. Ten patients were enrolled: four patients underwent retropubic RP and lymph node dissection, five patients underwent partial nephrectomy, and one patient underwent ureteroplasty. Fluorophore was injected transrectally with TRUS guidance during RP in order to assess the lymph nodes. During partial nephrectomy, the compound was injected intravenously to differentiate the tumor from parenchyma by its blood supply. During ureteroplasty, the indocyanine green solution was injected into the renal pelvis to dye the ureter and locate the stricture. RESULTS: Sensitivity of this technique for visualization of sentinel lymph nodes was 100%, and specificity was 73.3%. In patients who underwent partial nephrectomy, all lesions were malignant and hypofluorescent when compared with healthy parenchyma. SPY allowed us to determine the location and extension of the stricture during ureteroplasty. No hypersensitivity reactions or complications were observed during injection of the compound.