Ultrasound stimulated piezoelectric barium titanate and boron nitride nanotubes in nonconductive poly-ε-caprolactone nanofibrous scaffold for bone tissue engineering.

Nanomaterials can provide unique solutions for the problems experienced in tissue engineering by improving a scaffold's physico-bio-chemical properties. With its piezoelectric property, bone is an active tissue with easy adaptation and remodeling through complicated mechanisms of electromechanical operations. Although poly(ε-caprolactone) (PCL) is an excellent polymer for bone tissue engineering, it is lack of conductivity. In this study, piezoelectric barium titanates (BaTiO3) and boron nitride nanotubes (BNNTs) are used as ultrasound (US) stimulated piezoelectric components in PCL to mimic piezoelectric nature of bone tissue. Electric-responsive Human Osteoblast cells on the scaffolds were stimulated by applying low-frequency US during cell growth. Biocompatibility, cell adhesion, alkaline phosphatase activities and mineralization of osteoblast cells on piezo-composite scaffolds were investigated. BaTiO3or BNNTs as reinforcement agents improved physical and mechanical properties of PCL scaffolds.In vitrostudies show that the use of BaTiO3or BNNTs as additives in non-conductive scaffolds significantly induces and increases the osteogenic activities even without US stimulation. Although BaTiO3is one of the best piezoelectric materials, the improvement is more dramatic in the case of BNNTs with the increased mineralization, and excellent chemical and mechanical properties.

Investigation of effects of transferrin-conjugated gold nanoparticles on hippocampal neuronal activity and anxiety behavior in mice.

Gold nanoparticles (GNPs) have been widely used in medicine such as imaging, drug delivery and therapeutics due to their multifunctional properties. Alterations in neuronal function may contribute to various neurological diseases. Transferrin plays a primary role in iron transportation and delivery and has recently been utilized for drug delivery to the brain. We have investigated effects of transferrin-conjugated GNPs (Tf-GNPs) on anxiety and locomotor behavior in vivo and also hippocampal neuronal activity ex vivo. Electrophysiological effects of Tf-GNP on hippocampal neurons were determined by patch clamp method. Fifteen male young adult C57BL/6 mice were randomly divided into three groups as control (200 µL PBS), GNP (bare GNP; 2.2 µg/g in PBS) and Tf-GNPs (2.2 µg/g Tf-GNP). Animals intraperitoneally received the respective treatments for seven consecutive days and were subjected to elevated plus maze (EPM) and open field tests (OFT). Ex vivo, firing frequency of the neurons significantly increased by GNP treatment (p < 0.001). In vivo, animals in Tf-GNP group showed significantly longer distance in open arms but significantly lower number of entries to the open arms in EPM (p < 0.05). Mice received bare GNPs had significantly higher locomotor activity in OFT (p < 0.05), while Tf-GNP did not alter the locomotor activity significantly (p = 0.051). Animals in Tf-GNP group spent significantly longer time in the peripheral zone in OFT (p < 0.05). The present findings have shown that Tf-GNP induces anxiety-like behavior without altering spontaneous firing rate of hippocampal neurons. We suggest that neurobiological effects of Tf-GNP should be pre-determined before using in medical applications.

Discrimination of Receptor-Mediated Endocytosis by Surface-Enhanced Raman Scattering.

Cellular energy required for the maintenance of cellular life is stored in the form of adenosine triphosphate (ATP). Understanding cellular mechanisms, including ATP-dependent metabolisms, is crucial for disease diagnosis and treatment, including drug development and investigation of new therapeutic systems. As an ATP-dependent metabolism, endocytosis plays a key role not only in the internalization of molecules but also in processes including cell growth, differentiation, and signaling. To understand cellular mechanisms including endocytosis, many techniques ranging from molecular approaches to spectroscopy are used. Surface-enhanced Raman scattering (SERS) is shown to provide valuable label-free molecular information from living cells. In this study, receptor-mediated endocytosis was investigated with SERS by inhibiting endocytosis with ATP depletion agents: sodium azide (NaN3) and 2-deoxy-d-glucose (dG). Human lung bronchial epithelium (Beas-2b) cells, normal prostate epithelium (PNT1A) cells, and cervical cancer epithelium (HeLa) cells were used as models. First, the effect of NaN3 and dG on the cells were examined through cytotoxicity, apoptosis-necrosis, ATP assay, and uptake inhibition analysis. An attempt to relate the spectral changes in the cellular spectra to the studied cellular events, receptor-mediated endocytosis inhibition, was made. It was found that the effect of two different ATP depletion agents can be discriminated by SERS, and hence receptor-mediated endocytosis can be tracked from single living cells with the technique without using a label and with limited sample preparation.

Development of a SERS based cancer diagnosis approach employing cryosectioned thyroid tissue samples on PDMS.

An efficient SERS based novel analytical approach named Cryosectioned-PDMS was developed systematically and evaluated applying on 64 thyroid biopsy samples. To utilize thyroid biopsy samples, a 20-µl volume of h-AgNPs suspension was dropped on a 5-µm thick cryosectioned biopsy specimen placed on the PDMS coated glass slide. The SERS spectra from a 10 × 10 points array acquired by mapping 22.5 µm × 22.5 µm sized area from suspended dried droplets placed on the tissue surface. The probability of correctly predicted performance for diagnosis of malignant, benign and healthy tissues was resulted in the accuracy of 100 % for the spectral bands at 667, 724, 920, 960, 1052, 1096, 1315 and 1457 cm-1 using PCA-fed LDA machine learning. The Cryosectioned-PDMS biophotonic approach with PCA-LDA predictive model demonstrated that the vibrational signatures can accurately recognize the fingerprint of cancer pathology from a healthy one with a simple and fast sample preparation methodology.

Bulbar Urethral Stents for Bulbar Urethral Strictures: Long-Term Follow-Up after Stent Removal.

BACKGROUND/AIM: The aim of this study was to assess long-term clinical efficacy of temporary bulbar urethral stent (BUS) used for treatment of recurrent bulbar urethral stricture (US). MATERIALS AND METHODS: A total of 168 patients with recurrent bulbar US who underwent BUS placement after internal urethrotomy between 2009 and 2019 were enrolled. An indwelling time of 12 months was planned for the stents. After stent removal, the criteria for success of BUS treatment were defined as follows: no evidence of stricture on urethrogram or endoscopy, more than 15 mL/s of urinary peak flow, and no recurrent urinary tract infections. Patients were divided into 2 groups based on clinical success and compared. RESULTS: The mean age, US length, and indwelling time were 46.7 (±8.3) years, 2.32 (±0.4) cm, and 9.7 (±2.3) months, respectively. Median (range) follow-up was 71 (8-86) months. Clinical success was achieved in 77.9% patients. Longer indwelling time (8-18 [81.88%] vs. 3-7 [60%] months) and US length <2 cm (84.25% [<2 cm] vs. 58.5% [≥2 cm]) were significantly associated with clinical success (p < 0.05). CONCLUSION: This study is both the largest patient series and the longest follow-up for BUS in bulbar US. Our results suggest that BUS can be a safe and minimally invasive treatment alternative among bulbar US treatment options.

SERPIN A5 may have a potential as a biomarker in reflecting the improvement of semen quality in infertile men who underwent varicocele repair.

We aimed to identify proteins that were differentially regulated in spermatozoal samples collected from fertile healthy men (FHM) and infertile patients with varicocele (IFPV) before and after varicocelectomy. Seminal samples were collected from 20 IFPV before and after varicocelectomy and from 14 FHM as controls. Samples underwent seminal examination and proteomic analysis. Extracted spermatozoal proteins were analysed using two-dimensional gel electrophoresis, and differentially regulated spermatozoal proteins (DRSPs) were identified. In particular, attention was placed on those DRSPs in which the concentration changed after varicocelectomy and corrected to approximate levels observed in FHM. Varicocelectomy significantly improved the sperm count and concentration in IFPV (p < 0.05). Proteomic analysis showed that 11 DRSPs were identified when comparisons were made among the three groups. Among these 11 proteins, change in the SERPIN A5 concentrations was notable because it was 100-fold downregulated in pre-operative IFPV samples and nearly resembled to control concentrations following varicocelectomy. Western blot analysis using an anti-SERPIN antibody validated the changes observed in SERPIN A5 levels before and after varicocelectomy operation. Increase in SERPIN A5 after varicocelectomy may be due to improvement in semen quality, suggesting that SERPIN A5 is a potential seminal biomarker for assessment of semen quality in varicocele-related infertility.

Buried penis in adults as a complication of circumcision: Surgical management and long-term outcomes.

We aimed to evaluate the feasibility and long-term functional outcomes of surgical correction of adult buried penis patients due to complications of childhood circumcision. A retrospective analysis was performed for patients who underwent treatment for buried penis between 1997 and 2019. An autologous split-thickness skin graft (STSG) was used. Surgical management steps included circumcision, resection of the bands between the corpora and other tissues, harvesting of STSG from femoral region and graft application. Surgical and functional outcomes were the primary end points. Thirteen patients were included with a mean age of 22.4 years and median body mass index 27. Patients had similar symptoms, including sexual dysfunction, inadequate penile length, impossible penetration and decreased quality of life. No early post-operative complication was seen. During a median of 44-month follow-up, post-operative long-term complications were seen in 4 (30%) patients: decreased graft sensation (n = 2); graft contracture five months after surgery (n = 1); and retarded ejaculation (n = 1). Patients' post-operative three-month International Index of Erectile Function (IIEF) score and sexual satisfaction score (SSS) significantly increased compared with patients' pre-operative scores (IIEF; 22.8 vs. 14.1, p = .03, SSS; 8.7 vs. 3.2, p < .01). Buried penis is a rare but challenging condition. Patients had excellent graft acceptance with successful functional outcomes.

Comparability of Raman Spectroscopic Configurations: A Large Scale Cross-Laboratory Study.

The variable configuration of Raman spectroscopic platforms is one of the major obstacles in establishing Raman spectroscopy as a valuable physicochemical method within real-world scenarios such as clinical diagnostics. For such real world applications like diagnostic classification, the models should ideally be usable to predict data from different setups. Whether it is done by training a rugged model with data from many setups or by a primary-replica strategy where models are developed on a 'primary' setup and the test data are generated on 'replicate' setups, this is only possible if the Raman spectra from different setups are consistent, reproducible, and comparable. However, Raman spectra can be highly sensitive to the measurement conditions, and they change from setup to setup even if the same samples are measured. Although increasingly recognized as an issue, the dependence of the Raman spectra on the instrumental configuration is far from being fully understood and great effort is needed to address the resulting spectral variations and to correct for them. To make the severity of the situation clear, we present a round robin experiment investigating the comparability of 35 Raman spectroscopic devices with different configurations in 15 institutes within seven European countries from the COST (European Cooperation in Science and Technology) action Raman4clinics. The experiment was developed in a fashion that allows various instrumental configurations ranging from highly confocal setups to fibre-optic based systems with different excitation wavelengths. We illustrate the spectral variations caused by the instrumental configurations from the perspectives of peak shifts, intensity variations, peak widths, and noise levels. We conclude this contribution with recommendations that may help to improve the inter-laboratory studies.

Hexagonal boron nitrides reduce the oxidative stress on cells.

The molecular stress caused by a drug administered to treat a disorder on healthy cells appears as a side effect. In this study, we aim to understand the potential of hexagonal boron nitrides (hBNs) as a therapeutic agent to relieve the cellular stress exerted by drugs. First, the cytotoxicity of hBNs and their possible degradation product, boric acid (BA), on the embryonic mouse hippocampal cell line mHippo E-14 was assessed in a wide concentration range (4.4-440 µg ml-1) of boron including hBNs and BA for 24 and 72 h exposure. Then, cell cycle, reactive oxygen species generation, cell death mechanism and apoptotic body formation in nuclei with hBN and BA exposure were evaluated at increased concentrations and incubation times. Finally, the cells, exposed to doxorubicin (DOX), an anti-cancer chemotherapy drug, to exert oxidative stress, were treated with hBNs and BA. The results indicate that hBNs decrease the oxidative stress at the concentrations that are nontoxic to cells. The study suggests that hBNs can open new venues for their investigation to reduce or eliminate the adverse effects of toxic drugs used in the treatment of several fatal diseases including neurological disorders and cancer with their slow degradation feature.

Tracing Size and Surface Chemistry-Dependent Endosomal Uptake of Gold Nanoparticles Using Surface-Enhanced Raman Scattering.

Surface-enhanced Raman scattering (SERS)-based single-cell analysis is an emerging approach to obtain molecular level information from molecular dynamics in a living cell. In this study, endosomal biochemical dynamics was investigated based on size and surface chemistry-dependent uptake of gold nanoparticles (AuNPs) on single cells over time using SERS. MDA-MB-231 breast cancer cells were exposed to 13 and 50 nm AuNPs and their polyadenine oligonucleotide-modified forms by controlling the order and combination of AuNPs. The average spectra obtained from 20 single cells were analyzed to study the nature of the biochemical species or processes taking place on the AuNP surfaces. The spectral changes, especially from proteins and lipids of endosomal vesicles, were observed depending on the size, surface chemistry, and combination as well as the duration of the AuNP treatment. The results demonstrate that SERS spectra are sensitive to trace biochemical changes not only the size, surface chemistry, and aggregation status of AuNPs but also the endosomal maturation steps over time, which can be simple and fast way for understanding the AuNP behavior in single cell and useful for the assisting and controlling of AuNP-based gene or drug delivery applications.

Surface-Enhanced Raman Scattering for Label-Free Living Single Cell Analysis.

Single cell analysis is an active research area with the hope that cellular process can be deciphered from a single living cell other than a cell population. Surface enhanced Raman scattering (SERS) has been increasingly investigated for single cell analysis with its ability to provide information about real-time dynamics of molecular processes taking place in living cells, especially upon external stimulation, in a contactless, noninvasive, and nondestructive way. In this perspective, the fundamental concepts of single cell-SERS analysis including origin of spectral bands and experimental parameters for spectral reproducibility are summarized along with the recent developments.

Boron nitride nanotubes for gene silencing.

BACKGROUND: Non-viral gene delivery is increasingly investigated as an alternative to viral vectors due to low toxicity and immunogenicity, easy preparation, tissue specificity, and ability to transfer larger sizes of genes. METHODS: In this study, boron nitride nanotubes (BNNTs) are functionalized with oligonucleotides (oligo-BNNTs). The morpholinos complementary to the oligonucleotides attached to the BNNTs (morpholino/oligo-BNNTs) are hybridized to silence the luciferase gene. The morpholino/oligo-BNNTs conjugates are administered to luciferase-expressing cells (MDA-MB-231-luc2) and the luciferase activity is monitored. RESULTS: The luciferase activity is decreased when MDA-MB-231-luc2 cells were treated with morpholino/oligo-BNNTs. CONCLUSIONS: The study suggests that BNNTs can be used as a potential vector to transfect cells. GENERAL SIGNIFICANCE: BNNTs are potential new nanocarriers for gene delivery applications.

Biocidal properties of maltose reduced silver nanoparticles against American foulbrood diseases pathogens.

Bee disease caused by spore-forming Paenibacillus larvae and Paenibacillus alvei is a serious problem for honey production. Thus, there is an ongoing effort to find an effective agent that shows broad biocidal activity with minimal environmental hazard. In this study, the biocidal effect of maltose reduced silver nanoparticles (AgNPs) is evaluated against American foulbrood and European foulbrood pathogens. The results demonstrate that the maltose reduced AgNPs are excellent short and long-term biocides against P. larvae isolates. The long-term effect suggests that the Ag+ ions are released from the AgNPs with increasing time in a controlled manner.

Surface-Enhanced Raman Scattering to Evaluate Nanomaterial Cytotoxicity on Living Cells.

The increasing number of reports about false positive or negative results from conventional cytotoxicity assays of nanomaterials (NMs) suggests that more reliable NM toxicity assessment methods should be developed. Here, we report a novel approach for nanotoxicity evaluation based on surface-enhanced Raman spectroscopy (SERS). Three model NMs were tested on two model cell lines and the results were validated by WST-1 cytotoxicity assay and annexin V-FITC/propidium iodide (PI) staining as apoptosis-necrosis assay. The localization of nanoparticles (NPs) in the cells and the cellular conditions upon NP incubation were visualized by transmission electron microscopy (TEM) and enhanced dark-field (EDF) microscopy. SERS revealed a broader view on the consequences of cell-NM interactions compared to the conventional cytotoxicity assays where only one aspect of toxicity can be measured by one assay type. The results suggest that SERS can significantly contribute to the cytotoxicity evaluation bypassing NM or assay component-related complications with less effort.

Water-dispersed thermo-responsive boron nitride nanotubes: synthesis and properties.

In this study, water-dispersed thermo-responsive boron nitride nanotubes (BNNTs) were prepared in a simple two-step process, where on the first step oligoperoxide was grafted via the interaction of amino groups (defects) of BNNTs with pyromellitic chloroanhydride fragments in oligoperoxide molecules. The second step involves N-isopropylacrylamide (NIPAM) graft polymerization 'from the surface' of oligoperoxide-functionalized BNNTs resulting in poly(N-isopropylacrylamide) (PNIPAM) coating. The pristine and functionalized BNNTs were characterized by thermogravimetric analysis, Fourier transform infrared spectroscopy, ultraviolet-visible spectrophotometry, dynamic light scattering, scanning electron microscopy and atomic force microscopy. PNIPAM-functionalized BNNTs exhibit excellent dispersibility in water and possess thermo-responsive properties. The water-dispersion of thermo-responsive PNIPAM-functionalized BNNTs can help their potential use in biomedical applications as 'smart' surfaces, nanotransducers and nanocarriers.

Gold Nanoparticles in Single-Cell Analysis for Surface Enhanced Raman Scattering.

The need for new therapeutic approaches in the treatment of challenging diseases such as cancer, which often consists of a highly heterogeneous and complex population of cells, brought up the idea of analyzing single cells. The development of novel techniques to analyze single cells has been intensively studied to fully understand specific alternations inducing abnormalities in cellular function. One of the techniques used for single cell analysis is surface-enhanced Raman spectroscopy (SERS) in which a noble metal nanoparticle is used to enhance Raman scattering. Due to its low toxicity and biocompatibility, gold nanoparticles (AuNPs) are commonly preferred as SERS substrates in single cell analysis. The intracellular uptake, localization and toxicity issues of AuNPs are the critical points for interpretation of data since the obtained SERS signals originate from molecules in close vicinity to AuNPs that are taken up by the cells. In this review, the AuNP-living cell interactions, cellular uptake and toxicity of AuNPs in relation to their physicochemical properties, and surface-enhanced Raman scattering from single cells are discussed.

Non-infected penile prosthesis cultures during revision surgery; comparison between antibiotic coated and non - coated devices.

INTRODUCTION: Aim of this study is to investigate bacterial growth on non-infected devices and compare antibiotic-coated and non-coated implants. MATERIALS AND METHODS: The charts of 71 patients who underwent revision surgeries for penile prosthesis between 1995 and 2013 were reviewed. Of those, 31 devices were antibiotic-coated prostheses, while 40 of the implants were non-coated. Swab cultures were routinely obtained from corporal, pump or reservoir site during the operation. If a bacterial biofilm was determined on the prosthesis, it was also cultured. RESULTS: A total of 5 different organisms were cultured from 18 patients. Of them, 4 devices were antibiotic-coated and the other 14 were non-coated devices. Staphylococcus epidermidis was the most common organism, while Staphylococcus hominis, beta hemolitic streptococcus, Escherichia coli and Proteus mirabilis were also cultured. All patients who had positive cultures were treated with appropriate antibiotics for four weeks postoperatively. Median follow-up time was 41 months, ranging between 8 and 82 months. One prosthesis (non-coated) became clinically infected in the follow-up period with a totally different organism. Culture positivity rates of antibiotic-coated and non-coated devices were 13% and 35% respectively and the result was significant (p=0.00254). CONCLUSIONS: Positive bacterial cultures are present on non-infected penile prostheses at revision surgeries in some of the patients. Antibiotic coated prostheses have much less positive cultures than non-coated devices.

Persistent very high output lymphatic drainage after radical nephrectomy successfully treated with surgical management.

Persistent lymphatic drainage is uncommon after most of the surgical operations. It is related with mechanical, nutritional and immunological problems as well as electrolyte imbalance and protein deficiency. It is most commonly seen in retroperitoneal surgeries including abdominal aortic surgery and retroperitoneal lymph node dissection. Conservative management is the first treatment choice and resolves the problem in most cases. However persistent high output drainage may not be resolved with conservative approach and surgical or invasive treatment may become necessary. Additionally, surgical management of persistent lymphatic drainage has not been sufficiently discussed in the literature. In this study, we present a case of persistent very high output lymphatic drainage after right radical nephrectomy which failed with conservative approach and was successfully treated with surgical management.

Source of cytotoxicity in a colloidal silver nanoparticle suspension.

Silver nanoparticles (AgNPs) are increasingly used in a variety of applications because of their potential antimicrobial activity and their plasmonic and conductivity properties. In this study, we investigated the source of cytotoxicity, genotoxicity, and reactive oxygen species (ROS) production on human dermal fibroblast and human lung cancer (A549) cell lines upon exposure to AgNP colloidal suspensions prepared with the simplest and most commonly used Lee­Meisel method with a variety of reaction times and the concentrations of the reducing agent. The AgNPs synthesized with shorter reaction times were more cytotoxic and genotoxic due to the presence of a few nanometer-sized AgNP seeds. The suspensions prepared with an increased citrate concentration were not cytotoxic, but they induced more ROS generation on A549 cells due to the high citrate concentration. The genotoxicity of the suspension decreased significantly at the higher citrate concentrations. The analysis of both transmission electron microscopy images from the dried droplet areas of the colloidal suspensions and toxicity data indicated that the AgNP seeds were the major source of toxicity. The completion of the nucleation step and the formation of larger AgNPs effectively decreased the toxicity.

Discrimination of urinary tract infection pathogens by means of their growth profiles using surface enhanced Raman scattering.

Urinary tract infection (UTI) is a widespread infection and affects millions of people around the globe. The gold standard for identification of microorganisms causing infection is urine culture. However, current methods require at least 24 h for the results. In clinical settings, identification and discrimination of bacteria with less time-consuming and cheaper methods are highly desired. In recent years, the power of surface-enhanced Raman scattering (SERS) for fast identification of bacteria and biomolecules has been demonstrated. In this study, we show discrimination of urinary tract infection causative pathogens within 1 h of incubation using principal component analysis (PCA) of SERS spectra of seven different UTI causative bacterial species. In addition, we showed differentiation of them at their different growth phases. We also analyzed origins of bacterial SERS spectra and demonstrated the highly dynamic structure of the bacteria cell wall during their growth. Graphical Abstract Collection of bacteria from urine sample, and their discrimination using their SERS spectra and multivariate analysis.