Modification of the Human Amniotic Membrane Using Different Cross-Linking Agents as a Promising Tool for Regenerative Medicine.

Human amniotic membranes (hAMs) obtained during cesarean sections have proven to be clinically useful as an interesting biomaterial in a wide range of tissue engineering applications such as ocular surface reconstruction, burn treatments, chronic wounds, or bedsore ulcers. It presents antimicrobial properties, promotes epithelization, reduces inflammation and angiogenesis, contains growth factors, and constitutes the reservoir of stem cells. However, variability in hAM stiffness and its fast degradation offers an explanation for the poor clinical applications and reproducibility. In addition, the preparatory method of hAM for clinical use can affect its mechanical properties, and these differences can influence its application. As a directly applied biomaterial, the hAM should be available in a ready-to-use manner in clinical settings. In the present study, we performed an analysis to improve the mechanical properties of hAM by the addition of various reagents used as protein cross-linkers: EDC/NHS, PEG-dialdehyde, PEG-NHS, dialdehyde starch, and squaric acid. The effect of hAM modification using different cross-linking agents was determined via infrared spectroscopy, thermal analyses, mechanical properties analyses, enzymatic degradation, and cytotoxicity tests. The use of PEG-dialdehyde, PEG-NHS, dialdehyde starch, and squaric acid increases the mechanical strength and elongation at the breaking point of hAM, while the addition of EDC/NHS results in material stiffening and shrinkage. Also, the thermal stability and degradation resistance were evaluated, demonstrating higher values after cross-linking. Overall, these results suggest that modification of human amniotic membrane by various reagents used as protein cross-linkers may make it easier to use hAM in clinical applications, and the presented study is a step forward in the standardization of the hAM preparation method.

Comparison of Strain and Shear Wave Elastography in Prostate Cancer Detection.

The aim of the study was to compare strain elastography with shear wave elastography in prostate cancer detection by comparing data gained during elastography with histological analysis after prostatectomy. Thirty patients with prostate cancer qualified for radical prostatectomy were enrolled into the study. All patients underwent transrectal strain elastography and shear wave elastography during pre-surgical evaluation. In each prostate, 36 regions were evaluated separately whether there was a suspicious prostate cancer lesion or not. Subsequently, the same regions were analyzed during histological analysis of the resected gland. Strain elastography and shear wave elastography (overall stiffness cutoff value = 35 kPa) in our study were characterized by overall sensitivities of 58.9% and 65.3% and specificities of 71.8% and 70.2%, respectively. Cutoff values specific to the zones in the shear wave elastography examination (peripheral zone: 35 kPa, transitional zone: 45 kPa) were characterized by an overall prostate cancer detection sensitivity and specificity of 63.4% and 73% respectively. Shear wave elastography examination revealed a higher sensitivity versus strain elastography, 63.4% versus 58.9% (p = 0.038, p < 0.05), and comparable specificity, 73.0% versus 71.8% (p = 0.547, p > 0.05), respectively. Sensitivity in prostate cancer detection for both methods is higher for larger lesions (except Gleason score 5 massive lesions in strain elastography). Controversially we observed a decrease in sensitivity for strain elastography in the detection of lesions with a large diameter and a Gleason score of 5 near the prostate capsule. Overall sensitivity in the diagnosis of prostate cancer is more significant for shear wave elastography versus strain elastography.

Shear Wave Elastography in the Evaluation of the Urethral Sphincter Complex after Radical Prostatectomy.

Post-prostatectomy pelvic floor muscle rehabilitation has a significant impact on urinary continence recovery. The aim of our study was the evaluation of urethral sphincter complex using shear wave elastography in patients after radical prostatectomy, with and without postsurgical pelvic floor muscle rehabilitation. Thirty-three patients were included in the study. The severity of urinary incontinence after radical prostatectomy was evaluated. Transrectal ultrasound examination was performed in all patients with shear wave elastography to visualize the urethral sphincter complex and estimate its length. Statistical analysis revealed that higher than average urethral sphincter complex stiffness correlates with a smaller number of pads used per day (p < 0,05) and better urine continence based on scales: subjective 0-10 (p < 0.05) and International Consultation on Incontinence Questionnaire-Urinary Incontinence Short Form (ICIQ-UI SF) (p < 0.05). The post-prostatectomy pelvic floor muscle rehabilitation group had statistically significant higher stiffness of the urethral sphincter complex compared with the group without rehabilitation (p < 0.05). The study found that shear wave elastography is a valuable method in evaluation of the urethral sphincter complex.

Application of three-dimensional ultrasonography (3D ultrasound) to pretreatment evaluation of plastic induration of the penis (Peyronie's disease).

AIM: Peyronie's disease (PD) or plastic induration of the penis, require complete evaluation of plaques in order to decide the best therapeutic option for patient. The purpose of this study is to compare the findings of three-dimensional ultrasound (3D US) and two-dimensional ultrasound (2D US) in patients with PD. MATERIALS AND METHODS: Twenty patients with PD aged 30 to 72 years were included in study. The examination was performed with a 12 MHz linear probe, using 2D US and 3D US. Localization and size of plaques were determined and time needed for imagine acquisition was determined in every case. RESULTS: 3D ultrasound permits the visualization of the entire plaque in the coronal plane of plaque with its precise measurements. No statistical difference in plaque dimensions and its surface area assessment using 3D US and 2D US was found (127.72 mm² vs. 128.74 mm², p>0.05). The possibility to perform detailed analysis of the acquired images using generated digital cube reduced the average duration of the acquisition to 69.8 seconds (median 64 seconds) for 3D US vs. 151.25 seconds (median 145.5 seconds) for 2D US (p<0.05). A supplementary plaque was detected using 3D US. CONCLUSIONS: 3D US seems to be a valuable complement of 2D US for patients with PD. The acquisition time is significantly reduced using 3D US comparing to 2D US and thus it is more comfortable for the patient.

Caspase 3 as a Novel Marker to Distinguish Chromophobe Renal Cell Carcinoma from Oncocytoma.

Despite advances in our understanding of the biology of chromophobe renal cell carcinoma (ChRCC) and renal oncocytoma (RO), the differential diagnosis among these tumors remains one of the most problematic in renal pathology. Today, CK7 is the most recommended marker to distinguish these entities, however it appears insufficiently accurate by itself. This study aimed to find an easily accessible IHC stain that might out-compete CK7 in this field. Expressions of CK7, cyclin D1, p16, survivin, CD138, Ki-67 and caspase 3 (CASP3) were analyzed in a total of 27 cases (20 ROs and 7 ChRCCs). Immunoreactivity was assessed based on a combined score of the extent and intensity of staining. Compared to RO, a higher percentage of the total ChRCCs stained positive for CK7 (67% vs. 22%, respectively) and CASP3 (86% vs. 25%) (P < 0.005). The differences in staining with cyclin D1, p16, survivin, CD138 and Ki-67 turned out to be statistically insignificant in differentiating ChRCC from RO. CASP3 is a promising marker in distinguishing ChRCC from RO and may represent an alternative for CK7. Cyclin D1, p16, survivin, CD138 and Ki-67 cannot be used to distinguish these neoplasms.

Application of amniotic membrane in reconstructive urology; the promising biomaterial worth further investigation.

Introduction: In reconstructive urology, autologous tissues such as intestinal segments, skin, and oral mucosa are used. Due to their limitations, reconstructive urologists are waiting for a novel material, which would be suitable for urinary tract wall replacement. Human amniotic membrane (AM) is a naturally derived biomaterial with a capacity to support reepithelization and inhibit scar formation. AM has a potential to become a considerable asset for reconstructive urology, i.e., reconstruction of ureters, urinary bladder, and urethrae. Areas covered: This review aims to discuss the potential application of human AM in reconstructive urology. The environment for urinary tract healing is particularly unfavorable due to the presence of urine. Due to its fetal origin, the bioactivity of AM is orientated to induce intrinsic regeneration mechanisms and inhibit scarring. This review introduces the concept of applying human AM in reconstructive urology procedures to improve their outcomes and future tissue engineering based strategies. Expert opinion: Many fields of medicine that have accomplished translational research have proven the usefulness of AM in clinical practice. There is an urgent need for studies to be conducted on large animal models that might convincingly demonstrate the underestimated potential of AM to urologists around the world.

Elastography in prostate gland imaging and prostate cancer detection.

Transrectal prostate biopsies under ultrasonography guidance remain the gold standard for the detection of prostate cancer (PCa). Transrectal ultrasonography (TRUS), however, has a limited sensitivity in PCa detection. Prostate elastography (TRES) increases the sensitivity of a TRUS examination. Therefore, the aim of this review is to discuss the usefulness of TRES in prostate gland imaging for the diagnosis and management of prostate cancer based on published literature. The advantages of transrectal elastography were analysed in the context of better diagnostic performance provided by this method. TRES provides additional information for the detection and biopsy guidance concerning prostate cancer, enabling a significant reduction in the number of biopsies.

Are agricultural and natural sources of bio-products important for modern regenerative medicine? A review.

[b] Abstract Introduction and objectives[/b]. As tissue engineering and regenerative medicine have continued to evolve within the field of biomedicine, the fundamental importance of bio-products has become increasingly apparent. This true not only in cases where they are derived directly from the natural environment, but also when animals and plants are specially bred and cultivated for their production. [b]Objective.[/b] The study aims to present and assess the global influence and importance of selected bio-products in current regenerative medicine via a broad review of the existing literature. In particular, attention is paid to the matrices, substances and grafts created from plants and animals which could potentially be used in experimental and clinical regeneration, or in reconstructive procedures. [b]Summary.[/b] Evolving trends in agriculture are likely to play a key role in the future development of a number of systemic and local medical procedures within tissue engineering and regenerative medicine. This is in addition to the use of bio-products derived from the natural environment which are found to deliver positive results in the treatment of prospective patients.

Novel surgical techniques, regenerative medicine, tissue engineering and innovative immunosuppression in kidney transplantation.

On the 60th anniversary of the first successfully performed renal transplantation, we summarize the historical, current and potential future status of kidney transplantation. We discuss three different aspects with a potential significant influence on kidney transplantation progress: the development of surgical techniques, the influence of regenerative medicine and tissue engineering, and changes in immunosuppression. We evaluate the standard open surgical procedures with modern techniques and compare them to less invasive videoscopic as well as robotic techniques. The role of tissue engineering and regenerative medicine as a potential method for future kidney regeneration or replacement and the interesting search for novel solutions in the field of immunosuppression will be discussed. After 60 years since the first successfully performed kidney transplantation, we can conclude that the greatest achievements are associated with the development of surgical techniques and with planned systemic immunosuppression.

New Amniotic Membrane Based Biocomposite for Future Application in Reconstructive Urology.

OBJECTIVE: Due to the capacity of the amniotic membrane (Am) to support re-epithelisation and inhibit scar formation, Am has a potential to become a considerable asset for reconstructive urology i.e., reconstruction of ureters and urethrae. The application of Am in reconstructive urology is limited due to a poor mechanical characteristic. Am reinforcement with electrospun nanofibers offers a new strategy to improve Am mechanical resistance, without affecting its unique bioactivity profile. This study evaluated biocomposite material composed of Am and nanofibers as a graft for urinary bladder augmentation in a rat model. MATERIAL AND METHODS: Sandwich-structured biocomposite material was constructed from frozen Am and covered on both sides with two-layered membranes prepared from electrospun poly-(L-lactide-co-E-caprolactone) (PLCL). Wistar rats underwent hemicystectomy and bladder augmentation with the biocomposite material. RESULTS: Immunohistohemical analysis (hematoxylin and eosin [H&E], anti-smoothelin and Masson's trichrome staining [TRI]) revealed effective regeneration of the urothelial and smooth muscle layers. Anti-smoothelin staining confirmed the presence of contractile smooth muscle within a new bladder wall. Sandwich-structured biocomposite graft material was designed to regenerate the urinary bladder wall, fulfilling the requirements for normal bladder tension, contraction, elasticity and compliance. Mechanical evaluation of regenerated bladder wall conducted based on Young's elastic modulus reflected changes in the histological remodeling of the augmented part of the bladder. The structure of the biocomposite material made it possible to deliver an intact Am to the area for regeneration. An unmodified Am surface supported regeneration of the urinary bladder wall and the PLCL membranes did not disturb the regeneration process. CONCLUSIONS: Am reinforcement with electrospun nanofibers offers a new strategy to improve Am mechanical resistance without affecting its unique bioactivity profile.

Nanovehicles as a novel target strategy for hyperthermic intraperitoneal chemotherapy: a multidisciplinary study of peritoneal carcinomatosis.

In general, detection of peritoneal carcinomatosis (PC) occurs at the late stage when there is no treatment option. In the present study, we designed novel drug delivery systems that are functionalized with anti-CD133 antibodies. The C1, C2 and C3 complexes with cisplatin were introduced into nanotubes, either physically or chemically. The complexes were reacted with anti-CD133 antibody to form the labeled product of A0-o-CX-chem-CD133. Cytotoxicity screening of all the complexes was performed on CHO cells. Data showed that both C2 and C3 Pt-complexes are more cytotoxic than C1. Flow-cytometry analysis showed that nanotubes conjugated to CD133 antibody have the ability to target cells expressing the CD133 antigen which is responsible for the emergence of resistance to chemotherapy and disease recurrence. The shortest survival rate was observed in the control mice group (K3) where no hyperthermic intraperitoneal chemotherapy procedures were used. On the other hand, the longest median survival rate was observed in the group treated with A0-o-C1-chem-CD133. In summary, we designed a novel drug delivery system based on carbon nanotubes loaded with Pt-prodrugs and functionalized with anti-CD133 antibodies. Our data demonstrates the effectiveness of the new drug delivery system and provides a novel therapeutic modality in the treatment of melanoma.

Long-term influence of bone marrow-derived mesenchymal stem cells on liver ischemia-reperfusion injury in a rat model.

BACKGROUND: The aim of this study was to evaluate the long-term usefulness of intraportal injection of the bone marrow-derived mesenchymal stem cells (BM-MSCs) in limitation of experimentally induced ischemia-reperfusion injury (IRI) in a rat model. MATERIAL AND METHODS: Twenty Wistar rats were divided into 3 groups: donor group (n=5), study group (n=10), and control group (n=5). IRI was performed using a modified hanging-weight system after left portal triad occlusion in study group animals. Isolated autologous BM-MSCs were labeled with fluorochrome PKH-26 then intraportally injected into the rats in the study group. Control group animals were intraportally injected with 1 ml of PBS. Follow-up was 3 months, after which animals were sacrificed for histopathological examination. Migration of BM-MSCs into different organs was examined. RESULTS: H&E staining of liver tissue sections from "time zero" biopsies did not show many irregularities in structural or histological construction compared to liver sections from the control group. However, a small amount of centrilobular hepatocyte necrosis and coagulative necrosis with neutrophil infiltration areas was observed in liver sections of the study group. The migration assay of BM-MSCs labeled with PKH-26 showed the highest positive BM-MSCs staining (6%) in the spleen, while few positively stained cells were found (2%) in liver sections. No BM-MSCs were detected in brain, kidney, or lung tissues. CONCLUSIONS: These results suggest that intraportal bone marrow-derived mesenchymal stem cell injection is safe and cells do not migrate chaotically to other organs after targeted implementation.

Is regenerative medicine a new hope for kidney replacement?

The availability of kidney and other organs from matching donors is not enough for many patients on demand for organ transplant. Unfortunately, this situation is not better despite the many of new interesting projects of promoting family, cross or domino transplants. These inexorable global statistics forced medical researchers to find a new potential therapeutic option that would guarantee safety and efficacy for the treatment of ESRD comparable to kidney transplantation. The aim of our review is to summarize the scientific literature that relating to the modern as well as innovative experimental methods and possibilities of kidney regeneration and, in addition, to find whether the regenerative medicine field will be a new hope for curing the patient with renal disease complications. The most important achievements in the field of regenerative medicine of kidney, which were mentioned and described here, are currently cumulated in 4 areas of interest: stem cell-based therapies, neo-kidneys with specially designed scaffolds or cell-seeded matrices, bioartificial kidneys and innovative nanotechnologically bioengineered solutions. Nowadays, we can add some remarks that the regenerative medicine is still insufficient to completely replace current therapy methods used in patients with chronic kidney disease especially with the end-stage renal disease where in many cases kidney transplantation is the only one chance. But we think that development of regenerative medicine especially in the last 20 years brings us more and more closer to solve many of today's problems at the frontier of nephrology and transplantology.