Porcine Small Intestinal Submucosa (SIS) as a Suitable Scaffold for the Creation of a Tissue-Engineered Urinary Conduit: Decellularization,Biomechanical and Biocompatibility Characterization Using New Approaches

Bladder cancer (BC) is among the most common malignancies in the world and a relevant cause of cancer mortality. BC is one of the most frequent causes for bladder removal through radical cystectomy, the gold-standard treatment for localized muscle-invasive and some cases of high-risk, non-muscle-invasive bladder cancer. In order to restore urinary functionality, an autologous intestinal segment has to be used to create a urinary diversion. However, several complications are associated with bowel-tract removal, affecting patients’ quality of life. The present study project aims to develop a bio-engineered material to simplify this surgical procedure, avoiding related surgical complications and improving patients’ quality of life. The main novelty of such a therapeutic approach is the decellularization of a porcine small intestinal submucosa (SIS) conduit to replace the autologous intestinal segment currently used as urinary diversion after radical cystectomy, while avoiding an immune rejection. Here, we performed a preliminary evaluation of this acellular product by developing a novel decellularization process based on an environmentally friendly, mild detergent, i.e., Tergitol, to replace the recently declared toxic Triton X-100. Treatment efficacy was evaluated through histology, DNA, hydroxyproline and elastin quantification, mechanical and insufflation tests, two-photon microscopy, FTIR analysis, and cytocompatibility tests. The optimized decellularization protocol is effective in removing cells, including DNA content, from the porcine SIS, while preserving the integrity of the extracellular matrix despite an increase in stiffness. An effective sterilization protocol was found, and cytocompatibility of treated SIS was demonstrated from day 1 to day 7, during which human fibroblasts were able to increase in number and strongly organize along tissue fibres. Taken together, this in vitro study suggests that SIS is a suitable candidate for use in urinary diversions in place of autologous intestinal segments, considering the optimal results of decellularization and cell proliferation. Further efforts should be undertaken in order to improve SIS conduit patency and impermeability to realize a future viable substitute.     

Evaluation of growth and transfer of Staphylococcus aureus from poultry meat to surfaces of stainless steel and polyethylene and their disinfection

The growth of Staphylococcus aureus inoculated onto poultry meat was investigated under different incubation periods and temperature patterns. Transfer of this microorganism to surface materials and their disinfection was also evaluated. The evaluation of transfer was carried out by placing the contaminated meat cubes on stainless steel and polyethylene surfaces for 10 s and 10 min each, and the surfaces were disinfected with 0.5% chlorhexidine digluconate (CHXdG) for 1 and 10 min each. After 24 h, there was a significant increase of the bacteria count at 20 °C, but not at temperatures between 7 and 15 °C. Significant counts of S. aureus were transferred after a few seconds of contact of the cubes with both materials, and significant differences of transferred cell counts were not detected among the surface materials or durations of contact. The CHXdG solution was able to inactivate all the transferred cells after 10 min of exposure; however, the same result was not observed with 1-min exposure. The time of contact and the type of surface material did not influence the quantity of the transferred cells. The 0.5% CHXdG solution was effective for the disinfection of the contaminated surfaces without previous cleaning.     

Interferon antibodies in patients with chronic hepatitic C virus infection treated with recombinant interferon alpha-2 alpha

Patients treated with alpha-2a interferon for chronic hepatitis C may produce anti-interferon antibodies whose effect, if any, on the individual response to therapy has not been fully clarified. The prevalence and kinetics of anti-interferon, including those of neutralizing type, have been studied in 60 patients with chronic hepatitis C enrolled in a randomized controlled trial of recombinant alpha-2a interferon. Thirty patients received interferon while 30 were untreated controls. Two different methods, an enzyme immunoassay and an antiviral neutralization bioassay, were used and serial serum samples from each patient were analyzed. Enzyme immunoassay-positive anti-interferon appeared in 60.7% of treated patients within 6 months of therapy; antiviral neutralization bioassay-positive anti-interferon appeared in 52.9% of these enzyme immunoassay-positive patients, and was associated with high enzyme immunoassay reactivity and long-term persistence. Anti-interferon was detected in 75% of patients showing no response to interferon. Antibodies were also detected in three out of six patients who showed alanine aminotransferase normalization persisting up to the end of treatment and in 8 out of 14 patients who showed an initial marked reduction or even normalization of alanine aminotransferase, followed by reactivation of liver damage during treatment. Interestingly, patients who became anti-interferon positive before complete alanine aminotransferase normalization later showed reactivation of liver damage independently of interferon dose reduction, while patients who became positive for anti-interferon after complete alanine aminotransferase normalization either did not reactivate or did so only after interferon dose reduction.(ABSTRACT TRUNCATED AT 250 WORDS)     

Tissue Engineering and Regenerative Medicine in Pediatric Urology: Urethral and Urinary Bladder Reconstruction

In the case of pediatric urology there are several congenital conditions, such as hypospadias and neurogenic bladder, which affect, respectively, the urethra and the urinary bladder. In fact, the gold standard consists of a urethroplasty procedure in the case of urethral malformations and enterocystoplasty in the case of urinary bladder disorders. However, both surgical procedures are associated with severe complications, such as fistulas, urethral strictures, and dehiscence of the repair or recurrence of chordee in the case of urethroplasty, and metabolic disturbances, stone formation, urine leakage, and chronic infections in the case of enterocystoplasty. With the aim of overcoming the issue related to the lack of sufficient and appropriate autologous tissue, increasing attention has been focused on tissue engineering. In this review, both the urethral and the urinary bladder reconstruction strategies were summarized, focusing on pediatric applications and evaluating all the biomaterials tested in both animal models and patients. Particular attention was paid to the capability for tissue regeneration in dependence on the eventual presence of seeded cell and growth factor combinations in several types of scaffolds. Moreover, the main critical features needed for urinary tissue engineering have been highlighted and specifically focused on for pediatric application.     

Mechanical Behavior and Biodegradation of Poly(ε-caprolactone)/Starch Blends with and without Expansor

Summary The use of biodegradable polymers has provided an alternative to the problem of polymer-based products discarded in the environment. Poly(ε-caprolactone) (PCL) is a biodegradable polymer that has been used industrially, but it is very expensive. Starch is a potentially useful material for biodegradable plastics because of its natural abundance and low cost. The aim of this work was to examine the effect of adding azodicarbonomide (ADC) as an expansor to blends of PCL with corn starch. Different proportions, of ADC (0.1%, 0.2% and 0.3%, w/w) were added to pure PCL and to PCL/starch (50/50) blends and their properties were studied. Biodegradable blends of PCL with starch had a higher density than PCL alone and the addition of ADC reduced the density of the materials. The incorporation of starch increased the water absorption and ADC did not significantly alter this property. The incorporation of starch into PCL reduced the tensile strength and the elongation at break; ADC enhanced these reductions and also decreased the Young’s modulus of PCL. SEM showed that blends prepared with starch were immiscible, had a homogeneous dispersion of starch, and poor interfacial adhesion. The addition of ADC resulted in cells in the interior of the polymers. The 50/50 PCL/starch blends biodegraded faster than PCL, and ADC had no significant influence on the biodegradation of the blends but inhibited the biodegradation of PCL.     

Industrial Hydrogenation Process Monitoring Using Ultra-compact Near-Infrared Spectrometer and Chemometrics

The hydrogenation process of soybean oil is monitored through time-consuming methodologies that demand sample preparation and produce chemical residues. Thus, it is necessary to develop faster low-cost waste-free instrumentation methodologies. The aim of this work was to evaluate an ultra-compact near-infrared spectrometer in tandem with the partial least squares regression (PLSR) or support vector regression (SVR) in the control of the hydrogenation process. Models were used to predict the saturated fatty acids (SFA), unsaturated fatty acids (UFA), monounsaturated fatty acids (MUFA), trans fatty acids (TFA), polyunsaturated fatty acids (PUFA), and the iodine value (IV). The values predicted by the PLSR and SVR models were compared to the experimental values obtained by gas chromatography. A methodology for feature selection was also assessed, which was able to reduce by up to 85% the variables used in the models without loss of performance. The values obtained for root mean square error of cross validation, root mean square error of calibration, root mean square error of prediction, and r ² remained very close for both PLSR and SVR. Regarding RSD, all values were above 5% for the PLSR models, whereas for the SVR, the RSD presented values lower than 5% for IV and UFA. It is worth noting that the spectrometer used has low cost, effortless assembly, and easy handling, which allows its use in any environment. Through the results obtained, it was demonstrated that the ultra-compact NIRS spectrometer in tandem with PLSR or SVR represent an alternative to monitor the industrial hydrogenation process of soybean oil.     

Osteogenic differentiation of rat bone mesenchymal stem cells cultured on poly (hydroxybutyrate-co-hydroxyvalerate), poly (ε-caprolactone) scaffolds

Journal of Materials Science: Materials in Medicine - A thin endocrown restoration was often applied in endodontically treated teeth with vertical bite height loss or inadequate clinical crown...