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.

Systematic Investigation of Cellular Response to Hydroxyl Group Orientation Differences on Gold Glyconanoparticles.

Nanoparticle (NP) surfaces act as the interface as they interact with living systems and play a critical role in defining their cellular response. The nature of these interactions should be well understood to design safer and more effective NPs to be used in a wide range of biomedical applications. At the moment, it is not clear how a subtle change in surface chemistry will affect an NP's behavior in a biological system. Thus, understanding the role of such a small change is critical and may allow one to fine-tune a biological response. In this study, the cellular response to -OH orientation differences generated on gold glyconanoparticles, which are recently considered promising therapeutic agents as they mimic a glycocalyx, is investigated. As model molecules, glucose and mannose (C2 epimer) as monosaccharides and lactose and maltose (galactose and glucose as free units, C4 epimer) as disaccharides were chosen to monitor the cellular response in A549, BEAS-2b, and MDA-MB-231 cells through cellular uptake, cytotoxicity, and cell cycle progression. The three cell lines gave various and remarkable cellular responses to the same subtle -OH differences on gold glyconanoparticles, and it is determined that not only -OH orientation differences but also the number of saccharides on gold glyconanoparticles affect the cellular response. It was shown that mannose (C2 epimer to glucose) was significant with the promise of being a therapeutic agent for lung cancer therapy, whereas the toxicological profile of MDA-MB-231 cells was affected by AuNPs-glucose the most. This study demonstrates that clearly small chemical alterations on a NP surface can result in a significant cellular response. It can be concluded that the -OH orientation at the second and fourth carbon of a carbohydrate ring has a critical role in designing and engineering novel gold glyconanoparticles (consisting of monolayer mono- or disaccharides) for a specific cancer therapy.

Immediately repaired penile fractures: age is the only predictor of postoperative long-term functional outcomes.

Background: Penile fractures can lead to many functional complications, especially erectile dysfunction (ED). Few studies have evaluated the factors that predict late complications of an immediately repaired penile fracture. Aim: To identify the potential predictors of long-term poor functional outcomes following immediate surgical intervention for penile fractures. Methods: Sixty-eight consecutive patients with suspected penile fracture between 2003 and 2022 were retrospectively reviewed. Functional outcomes, postoperative complications, and follow-up duration were obtained from the records of follow-up visits. Age at presentation, location and length of the tunical tear, the presence of urethral rupture, and time to surgery were all analyzed as potential risk factors for postoperative functional outcomes. Outcomes: Postoperative erectile function and intercourse satisfaction were measured by the IIEF-5 (the 5-item version of the International Index of Erectile Function). Penile curvature, a palpable nodule, and paresthesia/numbness were detected by physical examination. Uroflowmetry was used to assess urinary flow in patients who underwent urethral repair. Results: Fifty-eight patients were analyzed. The mean ± SD age was 38.1 ± 10.4 years; the median follow-up was 79.0 months (range, 13-180); the median time to surgery was 9.8 hours (4-30); and the median tunical tear length was 15.5 mm (4-40). Urethral rupture was observed in 8 patients (13.8%). In univariable analyses, urethral rupture was associated with postoperative complications (P = .034). In addition, age at presentation and tunical tear size were significantly associated with postoperative complications and ED (P < .05). However, in multivariable analyses, only age at presentation significantly predicted postoperative complications and ED (P = .004 and P = .037). Clinical Implications: Age at presentation is the most important factor determining the prognosis of immediate surgical repair of the penile fracture, which aids in predicting potential complications and discussing them with patients prior to surgical intervention and during the follow-up period. Strengths and Limitations: The study's retrospective design is an important limitation. Furthermore, there were no data on an IIEF-5 outcome measuring preoperative erectile function. Conclusion: These results revealed an association between (1) urethral rupture, longer tunical tears, and older age and (2) the development of late complications. The remarkable finding of this study was that age at presentation was the only significant predictor of functional complications based on multivariable analyses. This relationship also remained robust in tests evaluating the covariance of the effects of aging on ED.

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.

Label-Free Surface Enhanced Raman Spectroscopy for Cancer Detection.

Blood is a vital reservoir housing numerous disease-related metabolites and cellular components. Thus, it is also of interest for cancer diagnosis. Surface-enhanced Raman spectroscopy (SERS) is widely used for molecular detection due to its very high sensitivity and multiplexing properties. Its real potential for cancer diagnosis is not yet clear. In this study, using silver nanoparticles (AgNPs) as substrates, a number of experimental parameters and scenarios were tested to disclose the potential for this technique for cancer diagnosis. The discrimination of serum samples from cancer patients, healthy individuals and patients with chronic diseases was successfully demonstrated with over 90% diagnostic accuracies. Moreover, the SERS spectra of the blood serum samples obtained from cancer patients before and after tumor removal were compared. It was found that the spectral pattern for serum from cancer patients evolved into the spectral pattern observed with serum from healthy individuals after the removal of tumors. The data strongly suggests that the technique has a tremendous potential for cancer detection and screening bringing the possibility of early detection onto the table.

European Registry of Materials: global, unique identifiers for (undisclosed) nanomaterials.

Management of nanomaterials and nanosafety data needs to operate under the FAIR (findability, accessibility, interoperability, and reusability) principles and this requires a unique, global identifier for each nanomaterial. Existing identifiers may not always be applicable or sufficient to definitively identify the specific nanomaterial used in a particular study, resulting in the use of textual descriptions in research project communications and reporting. To ensure that internal project documentation can later be linked to publicly released data and knowledge for the specific nanomaterials, or even to specific batches and variants of nanomaterials utilised in that project, a new identifier is proposed: the European Registry of Materials Identifier. We here describe the background to this new identifier, including FAIR interoperability as defined by FAIRSharing, identifiers.org, Bioregistry, and the CHEMINF ontology, and show how it complements other identifiers such as CAS numbers and the ongoing efforts to extend the InChI identifier to cover nanomaterials. We provide examples of its use in various H2020-funded nanosafety projects.

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.

Stimuli-responsive theranostic system: A promising approach for augmented multimodal imaging and efficient drug release.

Destruction of drug resistant and invisible micro-tumors requires innovative screening and treatment modalities. Theranostic nanosystems offering multimodal imaging and therapy are attractive platforms with potential to make micro-tumors visible to clinicians. Gold nanoparticles (AuNPs) are intrinsic theranostic agents and act as fluorescence quenchers. They can be easily transformed to multimodal imaging and combination therapy agents by combining them with various adjuvant therapies such as photodynamic therapy. In this study, we developed a highly specific, hybrid theranostic agent that is only activated when it meets with its stimuli at the site of interest. Surface-coated AuNPs were modified with Cathepsin B cleavable peptide (stimuli responsive linker) and Verteporfin (photosensitizer and fluorescence imaging agent). Unless the theranostic system meets with the internal stimuli in tumor cells, fluorescence is quenched due to AuNP-Verteporfin and Verteporfin-Verteporfin interactions. Following cellular internalization of the theranostic agent, fluorescence is gained by Cathepsin B cleavage and phototoxicity is initiated by light. The system was efficiently internalized by SKOV-3 cells and demonstrated high specificity towards its stimuli. In comparison to Verteporfin, ∼14-fold fluorescence increase, 81% fluorescence recovery and comparable toxicity were achieved. The system is a promising candidate for multimodal imaging and dual treatment to destroy the micro-tumors.

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.

Pharmaceutical applications of a nanospectroscopic technique: Surface-enhanced Raman spectroscopy.

Surface-enhanced Raman spectroscopy (SERS) is a very sensitive technique offering unique opportunities for detection and identification of molecules and molecular structures at extremely low concentrations even in complex sample matrixes. Since a nanostructured noble metal surface is required for the enhancement of Raman scattering, the acquired spectral information naturally originates from nanometer size domains making it a nanospectroscopic technique by breaking the diffraction limit of light. In this review, first Raman spectroscopy, its comparison to other related techniques, its modes and instrumentation are briefly introduced. Then, the SERS mechanism, substrates and the parameters influencing a SERS experiment are discussed. Finally, its applications in pharmaceuticals including drug discovery, drug metabolism, multifunctional chemo-photothermal-therapy-delivery-release-imaging, drug stability and drug/metabolite detection in complex biological samples are summarized and elaborated.

3D Fiber Reinforced Hydrogel Scaffolds by Melt Electrowriting and Gel Casting as a Hybrid Design for Wound Healing.

Emerging biomanufacturing technologies have revolutionized the field of tissue engineering by offering unprecedented possibilities. Over the past few years, new opportunities arose by combining traditional and novel fabrication techniques, shaping the hybrid designs in biofabrication. One of the potential application fields is skin tissue engineering, in which a combination of traditional principles of wound dressing with advanced biofabrication methods could yield more efficient therapies. In this study, a hybrid design of fiber-reinforced scaffolds combined with gel casting is developed and the efficiency for in vivo wound healing applications is assessed. For this purpose, 3D fiber meshes produced by melt electrowriting are selectively filled with photocrosslinkable gelatin hydrogel matrices loaded with different growth factor carrier microspheres. Additionally, the influence of the inclusion of inorganic bioactive glass particles within the composite fibrous mesh is evaluated. Qualitative evaluation of secondary wound healing criteria and histological analysis shows that hybrid scaffolds containing growth factors and bioactive glass enhances the healing process significantly, compared to the designs merely providing a fiber-reinforced bioactive hydrogel matrix as the wound dressing. This study aims to explore a new application area for melt electrowriting as a powerful tool in fabricating hybrid therapeutic designs for skin tissue engineering.

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.

Hyaluronic acid (HA)-Gd(III) and HA-Fe(III) microgels as MRI contrast enhancing agents.

Hyaluronic acid (HA) was crosslinked with Gd(III) and Fe(III) ions rendering physically crosslinked HA-metal(III) microgels as magnetic resonance imaging (MRI) enhancing contrast agents. These HA-Gd(III) and HA-Fe(III) microgels are injectable with size range, 50-5000 nm in water. The same isoelectric point, pH 1.2 ± 0.1, was measured for both microgels. HA-Gd(III) and HA-Fe(III) microgels are hemo-compatible biomaterials and can be safely used in intravascular applications up to 1000 µg/mL concentration. Furthermore, no significant toxicity was attained as 95 ± 8 and 81 ± 2% cell viability on L929 fibroblast cells at 100 µg/mL of HA-Gd(III) and HA-Fe(III) microgels were measured. Moreover, HA-Gd(III) microgels were found to afford significant contrast improvement capability in MRI with proton relaxivity, r1 = 2.11 mM-1 s-1, comparable with the values reported for Gd(III) labeled functionalized HA gel systems and commercial Gd based contrast agents.

Surface-enhanced infrared absorption spectroscopy for microorganisms discrimination on silver nanoparticle substrates.

Extracting molecular level label-free information from complex biological processes for a range of purposes including disease diagnosis and microbial identification and discrimination is always a challenging task. This is mostly due to lack of a technique providing rich molecular information with a high spatial and temporal resolution properties. Two surface-enhanced vibrational spectroscopic (SEVS) techniques, surface-enhanced Raman scattering (SERS) and surface-enhanced infrared absorption spectroscopy (SEIRAS), are recently attracting considerable attention to study biosystems at an interface since they can satisfy these requirements to a certain level by providing rich intrinsic molecular information from molecules and molecular systems in a close proximity of nanostructured noble metal surfaces. In this study, these two surface-enhanced vibrational spectroscopic techniques are comparatively evaluated for the discrimination and identification of Candida albicans (C. albicans), Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) by paying attention to the source of the observed spectral pattern. The citrate-reduced colloidal silver nanoparticles (AgNPs) were used as substrates. The results show that the SEIRAS provides very rich molecular information about the biomolecular species adsorbed onto AgNPs similar to the case of SERS. The discrimination power of SEIRAS is much improved compared to FTIR demonstrated by PCA analysis. This study suggests that SEIRAS can be a potential technique for microbial analysis.

Exploiting Urazole's Acidity for Fabrication of Hydrogels and Ion-Exchange Materials.

In this study, the acidity of urazole (pKa 5-6) was exploited to fabricate a hydrogel in two simple and scalable steps. Commercially available poly(hexamethylene)diisocyanate was used as a precursor to synthesize an urazole containing gel. The formation of urazole was confirmed by FT-IR and 1H-NMR spectroscopy. The hydrogel was characterized by microscopy imaging as well as spectroscopic and thermo-gravimetric analyses. Mechanical analysis and cell viability tests were performed for its initial biocompatibility evaluation. The prepared hydrogel is a highly porous hydrogel with a Young's modulus of 0.91 MPa, has a swelling ratio of 87%, and is capable of exchanging ions in a medium. Finally, a general strategy was demonstrated to embed urazole groups directly into a crosslinked material.

A Rational design of multi-functional nanoplatform: Fluorescent-based "off-on" theranostic gold nanoparticles modified with D-α-Tocopherol succinate.

It is crucial to develop nanocarrier systems to detect and treat drug-resistant micro tumors to prevent recurrence and/or metastasis of cancer. Due to their exceptional features such as biocompatibility, easy surface modification, serving as imaging and therapeutic agent, gold nanoparticles (AuNPs) draw attention as theranostic agents. It is beneficial to combine AuNPs with a second imaging and/or treatment modality such as photodynamic therapy (PDT). PDT is a non-mutagenic treatment approach in which photosensitizer is activated with light, generating reactive oxygen species and/or free radicals to destroy tumor cells. With the aim of developing "off-on" theranostic system, citrate stabilized spherical 13 nm AuNPs were densely coated with polyethylene glycol (PEG). To advance the theranostic feature of PEGylated AuNPs, they were further functionalized with FDA-Approved photosensitizer, Verteporfin (BPD-MA). Due to static quenching between BPD-MA and AuNPs as well as in between nearby BPD-MA molecules, the fluorescence of the ground state complex is quenched and the system is in "off" state. When BPD-MA molecules are cleaved from the AuNPs surface and diffuse away, fluorescence is recovered. Consequently, the system switches to the "on" state. Among the various mole ratios of BPD-MA carrying conjugates prepared, the most promising candidate was selected based on stability, quenching factor, and fluorescence recovery rate. The conjugate was further decorated with D-α-Tocopherol succinate (VitES) to increase the therapeutic efficacy of the theranostic agent via enhancing cellular uptake. Our results showed that it was possible to achieve as high as 80 times fluorescence quenching when the system was "off". As the system switched from "off" to "on" state, 51% of the fluorescence was recovered. When BPD-MA was immobilized on the PEGylated AuNPs, the phototoxic effect of BPD-MA increased twice against the MCF-7 cell line. Moreover, the developed system showed four times more phototoxicity than BPD-MA alone after it was decorated with VitES. Since the developed system is capable of dual imaging (computed tomography and fluorescence) and dual treatment (PDT and hyperthermia), it potentially offers superior imaging and therapy options for various types of in vitro/in vivo applications.

Synthesis and characterization of silver nanoparticles decorated polydopamine coated hexagonal boron nitride and its effect on wound healing.

BACKGROUND: Wound healing is an essential physiological process involving many cell types and their products acting in a marvellous harmony to repair damaged tissues. During the healing process, cellular proliferation and extracellular matrix remodelling stages could be interrupted by undesired factors including microorganisms and altered metabolic activities. In such a case, the process requires some external stimulants to accelerate or remediate the healing stages. METHODS: In this study, we report a multifunctional wound healing stimulating agent. In this context, hexagonal boron nitride (hBN) nanoparticles, silver nanoparticles (AgNPs) and polydopamine(pdopa) were used through mussel-inspired chemistry of dopamine to obtain pdopa coated hBN (hBN@pdopa) and AgNPs decorated hBN@pdopa (hBN@pdopa-AgNPs). These two nanostructures were investigated to observe stages of healing. RESULTS: AgNPs were chosen for inflammation reduction and hBN for induced cell proliferation and migration. In in vitro experiments, firstly, high cellular uptake capacity and biocompatibility of hBN@pdopa and hBN@pdopa-AgNPs were evaluated. They were also tested for their reaction against increased concentration of reactive oxygen species (ROS) in injured cells. Finally, their effect on cellular migration, intracellular tube formation and F-actin organization were monitored by light and confocal microscopy, respectively. CONCLUSION: The results clearly indicate that the hBN@pdopa-AgNPs significantly decrease ROS production, promote wound closure, and reorganize tube formation in cells.

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.

Investigation of the pathway dependent endocytosis of gold nanoparticles by surface-enhanced Raman scattering.

Endocytosis is a critical mechanism providing not only internalization of biomacromolecular structures but also communication with the environment where cells reside. Due to being the first step at the interaction interface, the route of cellular uptake has a major role governing the intracellular destinations and behaviors of molecular and non-molecular species including nanoparticles. To this end, various methods employing variety of techniques are investigated. In this study, surface-enhanced Raman spectroscopy (SERS) based approach for the investigation of endocytosis of gold nanoparticles (AuNPs) is reported. Internalization pathways of AuNPs were examined by flow cytometry via specific inhibitors for each endocytosis pathway type using three model cell lines Beas-2b, A549 and PNT1A. Macropinocytosis was blocked by cytochalasin D (CytoD), clathrin mediated endocytosis (CME) by sucrose (Scr), and caveolae mediated endocytosis (CE) by filipin (Fil). The results showed that cell type dependent AuNPs internalization affects not only the response of the cells to the inhibitors but also the obtained SERS spectra. SERS spectra of PNT1A cells treated with inhibitors was influenced most. The inhibition of each endocytosis pathway significantly affected the SERS spectral pattern and the spectral changes in different endocytosis pathways were clearly discriminated from each other. This means that SERS can significantly contribute to the investigation of different endosomal pathways from single living cells without any disruption of the cells or labeling.

Minimal invasive management of bladder neck contracture using Allium round posterior stent: the long-term results.

BACKGROUND: The purpose of this study was to assess the long-term clinical efficacy of temporary, Allium round posterior stent (RPS) used for treatment of recurrent bladder neck contracture (BNC). METHODS: Records of 42 patients with recurrent BNC who underwent Allium RPS placement after bladder neck incision, between 2009 and 2019, were analyzed. After stent removal, the success criteria for Allium RPS treatment were defined as: no evidence of stricture on urethrogram or endoscopy; more than 12 ml/sec of urinary peak flow; and no recurrent urinary tract infections. Based on clinical success, patients were divided into two groups and compared. Clinical success was evaluated with particular regard to stent indwelling time and contracture etiology. RESULTS: The mean ± standard deviation age, stricture length, and indwelling time were 66.7 ± 9 years, 2.4 ± 1.4 cm, and 7.7 ± 2.2 months, respectively. Median (range) follow-up was 59 (8-73) months. The etiologies of BNC in this cohort were 57.1% retropubic radical prostatectomy; and 42.9% transurethral resection of prostate. Overall clinical success was achieved in 64.3% and the success rates did not differ by etiology. The success rates were 54.2% and 77.8% (P = 0.118) for retropubic radical prostatectomy and transurethral resection of prostate, respectively. Longer indwelling time (8-14 vs 3-7, months) was significantly associated with clinical success (78.3% vs 47.4%, P = 0.040). CONCLUSION: Our data suggest that better clinical success was associated with longer indwelling time for stent in BNC treatment. In BNC management, Allium RPS treatment may be considered since its clinical efficacy is acceptable and tolerable.