Spontaneous bilayer wrapping of virus particles by a phospholipid Langmuir monolayer.

We report here the spontaneous formation of lipid-bilayer-wrapped virus particles, following the injection of "naked" virus particles into the subphase of a Langmuir trough with a liquid monolayer of lipids at its air-water interface. The virus particles are those of the well-studied cowpea chlorotic mottle virus, CCMV, which are negatively charged at the pH 6 of the subphase; the lipids are a 9:1 mix of neutral DMPC and cationic CTAB molecules. Before adding CCMV particles to the subphase we establish the mixed lipid monolayer in its liquid-expanded state at a fixed pressure (17.5 mN/m) and average area-per-molecule of (41Å2). Keeping the total area fixed, the surface pressure is observed to decrease at about 15 h after adding the virus particles in the subphase; by 37 h it has dropped to zero, corresponding to essentially all the lipid molecules having been removed from the air-water interface. By collecting particles from the subphase and measuring their sizes by atomic force microscopy, we show that the virus particles have been wrapped by lipid bilayers (or by two lipid bilayers). These results can be understood in terms of thermal fluctuations and electrostatic interactions driving the wrapping of the anionic virus particles by the cationic lipids. Spontaneous acquisition by a virus particle of, first, a hydrophobic lipid monolayer envelope and, then, a hydrophilic lipid bilayer envelope, as it interacts from the subphase with an oppositely charged Langmuir monolayer.

Controlling the surface charge of simple viruses.

The vast majority of plant viruses are unenveloped, i.e., they lack a lipid bilayer that is characteristic of most animal viruses. The interactions between plant viruses, and between viruses and surfaces, properties that are essential for understanding their infectivity and to their use as bionanomaterials, are largely controlled by their surface charge, which depends on pH and ionic strength. They may also depend on the charge of their contents, i.e., of their genes or-in the instance of virus-like particles-encapsidated cargo such as nucleic acid molecules, nanoparticles or drugs. In the case of enveloped viruses, the surface charge of the capsid is equally important for controlling its interaction with the lipid bilayer that it acquires and loses upon leaving and entering host cells. We have previously investigated the charge on the unenveloped plant virus Cowpea Chlorotic Mottle Virus (CCMV) by measurements of its electrophoretic mobility. Here we examine the electrophoretic properties of a structurally and genetically closely related bromovirus, Brome Mosaic Virus (BMV), of its capsid protein, and of its empty viral shells, as functions of pH and ionic strength, and compare them with those of CCMV. From measurements of both solution and gel electrophoretic mobilities (EMs) we find that the isoelectric point (pI) of BMV (5.2) is significantly higher than that of CCMV (3.7), that virion EMs are essentially the same as those of the corresponding empty capsids, and that the same is true for the pIs of the virions and of their cleaved protein subunits. We discuss these results in terms of current theories of charged colloidal particles and relate them to biological processes and the role of surface charge in the design of new classes of drug and gene delivery systems.

Nanotubols under H2O2 exposure: is it possible to poly-hydroxylate carbon nanotubes?

We present a combined experimental and theoretical study dedicated to analyze the variations in the surface chemistry of hydroxylated multiwalled carbon nanotubes (MWCNTs), so called nanotubols, when exposed to H2O2 at high temperatures. The formation, surface density, and distribution of oxygen-containing functional groups are studied by infrared (IR) and X-ray photoelectron spectroscopy (XPS), as well as density functional theory (DFT) calculations performed on model functionalized carbon nanotubes (CNTs). After H2O2 exposure, the initial composition of -OH, -C[double bond, length as m-dash]O, and -COOH substituents notably changes, with carbonyl -C[double bond, length as m-dash]O groups being the ones that show the most notable increase on the carbon surface. Our highly oxidized MWCNTs are partially soluble and form complex two-dimensional patterns at the air-water interface, as evidenced by Brewster angle microscopy. In a second step, these films can be transferred to solid substrates to form porous multilayered carbon nanostructures with complex morphologies. In particular, and for the first time, we report the synthesis of "stadium-like" configurations made of MWCNT units whose formation and stability are a direct consequence of the self-assembly process occurring at the air/water interface. DFT calculations suggest the formation of molecular islands of oxygen-containing functional groups on the CNT surface. In addition, nudged elastic band studies reveal that, for these adsorbed phases, the reaction between two neighboring OH groups to produce atomic oxygen and a physisorbed water molecule is characterized by energy barriers of ∼0.2 eV. These small values could be at the origin of the sizable increase in chemisorbed single-oxygen species determined by XPS data after H2O2 treatment at 60 °C. The simulation of the C 1s binding energies (BE) allows us to more clearly identify the different oxygen-containing functionalities as well as to reveal how the local atomic environment affects their characteristic BEs. Even if we were unable to polyhydroxylate our carbon nanotubes, we believe that H2O2-treated MWCNTs are interesting materials for more complex post-functionalization procedures that might lead to the fabrication of novel carbon nanostructures.

Initial Experience in the Use of Novel Auto-expandable Metal Ureteral Stent in the Treatment of Ureter Stenosis in Kidney Transplanted Patients.

INTRODUCTION: Ureter stenosis in renal transplantation patients is a relatively frequent complication that negatively conditions graft evolution. The use of ureteral stents is a valid treatment alternative to the use of double-J catheters in patients for whom surgery is not contemplated or after surgical recurrence. We present our initial experience with five patients treated using this technique. MATERIALS AND METHODS: We describe a total of five patients with ureteral stenosis after renal transplantation who were treated using ureteral stent model UVENTA (Taewoong Medical, Seoul, Korea) in our center. The median follow-up was 18 months (range, 4 to 38 months). We describe the clinical history of patients and previous treatments on ureteral stenosis. The technical procedure of placement is described. The clinical course is analyzed by measurement of renal function and imaging tests, as well as post-stent complications. Survival of the renal graft is evaluated. RESULTS: The procedure could be completed in all patients without complications. The technique was effective in all patients, with correction of creatinine value and hydronephrosis during the renal ultrasound test. One patient suffered a urinary tract infection episode associated with the use of the ureteral stent. One patient suffered the loss of the renal graft secondary to the development of cryoglobulins. One hundred percent of the ureteral stents are functioning as of the writing of this article. CONCLUSIONS: In renal transplantation patients with ureter stenosis, metallic stents are a useful technique with low morbidity and associated complications.

Encapsidated ultrasmall nanolipospheres as novel nanocarriers for highly hydrophobic anticancer drugs.

The design and construction of novel nanocarriers that have controlled shape and size and are made of inherently biocompatible components represents a milestone in the field of nanomedicine. Here, we show the tailoring of nanoliposphere-like particles for use as biocompatible drug nanocarriers. They are made with the building block components present in human lipoproteins by means of microfluidization, which allows for good size and polydispersity control, mimicking the physical properties of natural low-density lipoproteins (LDLs). This new type of nanocarrier has a negative surface charge and a hydrophobic core that allow the stabilization and encapsulation of hydrophobic anticancer drugs such as camptothecin, resulting in anticancer drug-loaded nanolipospheres. However, we found that the nanoparticles are unstable since their size increases with time. These nanolipospheres were further encapsidated using the non-cytotoxic capsid protein of the plant virus CCMV, which renders the nanoparticles stable. In a more general application, this new virus-like particle confers a controlled microenvironment for the transport of any kind of hydrophobic drug that can bypass the cellular defense mechanisms and deliver its payload.

Current issues in implementing do-not-resuscitate orders for cardiac patients. / Problemática actual en la implementación de la orden de no reanimar en el paciente cardiológico.

Cardiovascular diseases are still the most common cause of death, and heart failure is the most common reason for hospitalization of patients older than 65 years. However, Cardiology attributes low importance to end-of-life care. Cardiac patients' perception of their disease's prognosis and the results of cardiopulmonary resuscitation differ greatly from reality. The "do not resuscitate" order allows patients to pre-emptively express their rejection for cardiopulmonary resuscitation, thereby avoiding its potentially negative consequences. However, these orders are still underused and misinterpreted in cardiac patients. Most of these patients usually have no opportunity to have the necessary conversations with their attending physician on their resuscitation preferences. In this review, we performed an analysis of the causes that could explain this situation.

Expression of proteins FGFR3, PI3K, AKT, p21Waf1/Cip1 and cyclins D1 and D3 in patients with T1 bladder tumours: clinical implications and prognostic significance. / Expresión de las proteínas FGFR3, PI3K, AKT, p21Waf1/Cip1 y ciclinas D1 y D3 en pacientes con tumores de vejiga T1: implicaciones clínicas y significado pronóstico.

OBJECTIVE: To determine the differential protein expression of biomarkers FGFR3, PI3K (subunits PI3Kp110α, PI3KClassIII, PI3Kp85), AKT, p21Waf1/Cip1 and cyclins D1 and D3 in T1 bladder cancer versus healthy tissue and to study their potential role as early recurrence markers. MATERIAL AND METHOD: This is a prospective study that employed a total of 67 tissue samples (55 cases of T1 bladder tumours that underwent transurethral resection and 12 cases of adjacent healthy mucosa). The protein expression levels were assessed using Western blot, and the means and percentages were compared using Student's t-test and the chi-squared test. The survival analysis was conducted using the Kaplan-Meier method and the log-rank test. RESULTS: Greater protein expression was detected for FGFR3, PI3Kp110α, PI3KClassIII, cyclins D1 and D3 and p21Waf1/Cip1 in the tumour tissue than in the healthy mucosa. However, these differences were not significant for PI3Kp85 and AKT. We observed statistically significant correlations between early recurrence and PI3Kp110α, PI3KClassIII, PI3Kp85 and AKT (P=.003, P=.045, P=.050 and P=.028, respectively), between the tumour type (primary vs. recurrence) and cyclin D3 (P=.001), between the tumour size and FGFR3 (P=.035) and between multifocality and cyclin D1 (P=.039). The survival analysis selected FGFR3 (P=.024), PI3Kp110α (P=.014), PI3KClassIII (P=.042) and AKT (P=.008) as markers of early-recurrence-free survival. CONCLUSIONS: There is an increase in protein expression levels in bladder tumour tissue. The overexpression of FGFR3, PI3Kp110α, PI3KClassIII and AKT is associated with increased early-recurrence-free survival for patients with T1 bladder tumours.

Prostate Cancer Patients-Negative Biopsy Controls Discrimination by Untargeted Metabolomics Analysis of Urine by LC-QTOF: Upstream Information on Other Omics.

The existing clinical biomarkers for prostate cancer (PCa) diagnosis are far from ideal (e.g., the prostate specific antigen (PSA) serum level suffers from lack of specificity, providing frequent false positives leading to over-diagnosis). A key step in the search for minimum invasive tests to complement or replace PSA should be supported on the changes experienced by the biochemical pathways in PCa patients as compared to negative biopsy control individuals. In this research a comprehensive global analysis by LC-QTOF was applied to urine from 62 patients with a clinically significant PCa and 42 healthy individuals, both groups confirmed by biopsy. An unpaired t-test (p-value < 0.05) provided 28 significant metabolites tentatively identified in urine, used to develop a partial least squares discriminant analysis (PLS-DA) model characterized by 88.4 and 92.9% of sensitivity and specificity, respectively. Among the 28 significant metabolites 27 were present at lower concentrations in PCa patients than in control individuals, while only one reported higher concentrations in PCa patients. The connection among the biochemical pathways in which they are involved (DNA methylation, epigenetic marks on histones and RNA cap methylation) could explain the concentration changes with PCa and supports, once again, the role of metabolomics in upstream processes.

Graft Survival in Patients Who Received Second Allograft, Comparing Those With or Without Previous Failed Allograft Nephrectomy.

INTRODUCTION: Nowadays, the number of patients receiving a second graft is growing, and the management of failed grafts is still controversial. OBJECTIVE: Our objective was to analyze the influence of graft nephrectomy on graft and patient survival. MATERIALS AND METHODS: We retrospectively evaluated the demographic features and graft outcomes of 63 recipients who received second allografts between August 1985 and April 2013. They were divided into two groups: group A, those who underwent nephrectomy of failed graft (n = 21, 33.3%), and group B, those whose failed graft was retained (n = 42, 66.6%). χ2 and Mann-Whitney U tests were used to compare demographic characteristics and graft features in both groups. Kaplan-Meier test was used to analyze graft and patient survival. Finally, univariate and multivariate analysis was done using Cox regression. RESULTS: Demographic characteristics of donor and receptors were similar in both groups. Overall panel-reactive antibody (P = .040) showed statistically significant differences between groups (72.0 ± 25.3 in group A and 54.8 ± 30.0 in group B). Hemodialysis duration was longer in group A (P = .023, 112.2 ± 72.8 vs 70.9 ± 66.9 months). The percentage of patients who had delayed graft function was higher in group A (58.8% vs 27.3%, P = .029). Kaplan-Meier test found no differences between groups (P = .344); group A, 107.4 months (95% confidence interval [CI] 74.0 to 140.8) and group B, 82.7 months (95% CI 62.5 to 102.8). We found no differences in terms of patient survival (P = .798) with the Kaplan-Meier test. In group A, patient survival was 164.5 months (CI 137.7 to 191.31) and in group B, 152.0 months (95% CI 125.5 to 178.5). CONCLUSIONS: Failed graft nephrectomy did not show a negative impact on graft and patient survival.

Influence of Donor and Recipient Ages in Survival of Simultaneous Pancreas-Kidney Transplantation.

INTRODUCTION: Simultaneous pancreas-kidney transplantation (SPKT) is a well treatment for patients with insulin-dependent diabetes and end-stage renal disease. Donor age is a barrier to the acceptance of organs. Age matching has been extensively studied in kidney transplantation; however, there are no studies in graft survival after SPKT. We aimed to study the combined influence of the ages of the donors and recipients in graft survival after SPKT. MATERIAL AND METHODS: Donors and recipients are classified as younger (age <40 years) or older (age ≥40 years). There were four study groups (young-young, young-old, old-young, and old-old). They were evaluated retrospectively for demographic and clinical characteristics of donors and recipients and the long-term survival between 2001 and 2012 of kidney pancreas transplantation patients at our center. RESULTS: A total of 115 transplantations were performed. The four groups had 55 young-young, 40 young-old, 10 old-young, and 10 old-old patients. Serious complications occurred in 32%, 42%, 30%, and 40%, respectively, and deaths were 2%, 5%, 0%, and 20%, respectively, in the groups. Pancreas graft survival at 3 years for each group was 80%, 87, 5%, 90%, and 60%, respectively, and kidney graft survival was 92.7%, 90%, 90%, and 70%, respectively. Panel-reactive antibodies (PRAs) >30% were associated with poor graft survival, and serious postoperative complications associated with poor pancreas-kidney graft survival. CONCLUSIONS: In conclusion, both younger and older recipients show excellent long-term graft and patient survival after SPKTs from younger donors. We recommended that older-recipient SPKT be transplanted from younger donors because older recipients who have been transplanted from older donors had decreased survival.

Validation of the Pancreatic Donor Risk Index in Simultaneous Pancreas-Kidney Transplantation Performed in Córdoba Hospital From 2000 to 2015.

BACKGROUND: The Pancreatic Donor Risk Index (PDRI) was developed in 2010 in the United States to predict graft survival after pancreas transplantation, based on donor characteristics and logistical and technical conditions. The aim of the study was to validate the utility of PDRI as a pancreas allograft survival predictor in simultaneous pancreas-kidney transplantation (SPK) transplants performed in our hospital between 2000 and 2015. METHODS: This retrospective analysis of 126 SPK transplants was performed by the same surgical team from the years 2000 to 2015. Donor variables that are integrated in the PDRI were calculated (age, sex, race, creatinine serum levels, body mass index, height, cold ischemia time, cause of death, type of pancreas transplant). Pancreatic graft survival at 1 and 5 years was calculated by use of the Kaplan-Meier test. Comparison of survival curves between PDRI risk quartiles was calculated by use of the log-rank test. Association between graft survival and variables integrating the PDRI was calculated by use of univariate Cox regression analysis. RESULTS: Log-rank analysis found no statistically significant association between global graft survival and PDRI quartiles. Univariate Cox regression analysis showed a statistically significant association between graft survival and cold ischemia time (P < .05). CONCLUSIONS: PDRI was not a useful tool to predict pancreatic graft outcomes in a Spanish reference population.

Prognostic value of penile colour doppler ultrasonography for recovering erectile function after radical prostatectomy. / Valor pronóstico de la ecografía doppler color peneana en la recuperación de la función eréctil tras prostatectomía radical.

OBJECTIVE: To analyse the predictive utility of penile colour Doppler ultrasonography after the injection of vasoactive agents for recovering erectile function after radical prostatectomy. MATERIAL AND METHODS: A retrospective study was conducted on patients with erectile dysfunction after radical prostatectomy who were treated with intracavernous injections of prostaglandins E1 between January 1, 2006 and December 31, 2012. The study included patients with no history of erectile dysfunction prior to the surgery and who did not respond to medical treatment. Colour Doppler was performed on all patients after the intracavernous injection. A peak systolic velocity ≥30cm/sec and an end diastolic velocity ≤5cm/sec were considered normal haemodynamic values. We assessed the result of the treatment during the follow-up using the International Index of Erectile Function-5. RESULTS: We included 197 patients. The mean age was 60.8 (±6.3). The pathological diagnosis for all patients was adenocarcinoma, 74.1% of which were confined to the organ (T1-T2/Nx-N0). Treatment with injections after the surgery was started after a mean duration of 6.8 months (+3.5). The Doppler ultrasonography results were normal for 53 patients (26.9%). During the follow-up, 113 patients (57.4%) maintained functional erections; 55 of these patients (28%) did not require injections. Normal Doppler ultrasonography results were associated with a favourable response to treatment (p<.01). CONCLUSIONS: The prostaglandin E1 test will help provide a diagnosis in erectile dysfunction for patients who have undergone prostatectomies. The test helps provide information on the vascular condition of the penis and useful prognostic information for the follow-up of these patients.

Synthesis and characterization of extremely small gold nanoshells, and comparison of their photothermal conversion capacity with gold nanorods.

The current methods for preparing gold nanoshells (AuNSs) produce shells with a diameter of approximately 40 nm or larger, with a relatively large polydispersity. However, AuNSs with smaller diameters and more monodispersity are better suited for biomedical applications. In this work, we present a modified method for the preparation of AuNSs, based on the use of sacrificial silver nanoparticles (AgNPs). We customized the Lee-Meisel method to prepare small and monodisperse AgNPs that were used as sacrificial nanoparticles to prepare extremely small monodispersed AuNSs with an average diameter from 17 to 25 ± 4 nm. We found that these AuNSs are faceted, and that the oxidized silver likely dissolves out of the nanoparticles through some of the facets on the AuNSs. This leads to a silver oxide plug on the surface of the AuNSs, which has not been reported before. The smaller AuNSs, prepared under the best conditions, absorb in the near infrared region (NIR) that is appropriate for applications, such as photothermal therapy or medical imaging. The AuNSs showed absorption peaks in the NIR similar to those of gold nanorods (AuNRs) but with better photothermal capacity. In addition, because of their negative charge, these AuNSs are more biocompatible than the positively charged AuNRs. The synthesis of small, monodisperse, stable and biocompatible nanoparticles, like the ones presented in this work, is of prime importance in biomedical applications.

Graft Survival in Patients With Polycystic Kidney Disease With Nephrectomy of Native Kidney Pretransplant.

INTRODUCTION: Autosomal-dominant polycystic disease (ADPKD) represents 5%-10% of cases of end-stage renal failure. However, management of these patients in terms of whether or not to perform a transplant and optimal timing remains controversial. The objective of our analysis was to evaluate graft survival in patients with ADPKD in which we conduct pretransplant nephrectomy. METHODS: This retrospective study including renal transplant patients secondary to ADPKD in our hospital between January 2000 and December 2012. Pretransplant native kidney nephrectomy was indicated in cases of need for space or repeated complications (cysts). We compared the initial function and graft survival between groups of transplanted based on whether nephrectomy had been performed or not. RESULTS: Eighty-seven patients underwent a kidney transplant owing to ADPKD; 62% (n = 54) were male, with an average age of 55.22 years. Twenty-seven patients (30%) underwent nephrectomy native kidneys before transplantation. There were no serious postoperative complications. Patients who underwent nephrectomy (group 1) showed values of creatinine of 1.57 and 1.50 mg/dL at 3 and 6 months, respectively. In the no nephrectomy group, these values were 2.03 and 1.83 mg/dL, respectively. Graft survival after the first year was of 98% for group 1 and 95% for group 2. The 5-year implant survival was 95% and 80%, respectively. CONCLUSIONS: Native kidney nephrectomy before transplantation in ADPKD is safe in an experienced center, both in terms of surgery-related morbidity and mortality and graft survival and function.

Assessment and clinical factors associated with pain in patients undergoing transrectal prostate biopsy.

OBJECTIVES: To quantify the degree of pain experienced by patients who undergo ultrasound-guided transrectal prostate biopsy in standard clinical practice and assess the clinical factors associated with increased pain. MATERIAL AND METHODS: Analysis of a multicenter series of patients with prostate biopsy according to standard clinical practice. The biopsy was performed transrectally with a protocol of local anesthesia on the posterolateral nerve bundle. The pain was assessed at 20minutes into the procedure using the visual analog scale (0-10). The degree of pain was analyzed, and the association was studied using a univariate/multivariate analysis of selected clinical variables and the degree of pain. RESULTS: A total of 1188 patients with a median age of 64 years were analyzed. Thirty percent of the biopsies were diagnosed with a tumor. The median pain score was 2, with 65% of the patients reporting a pain score ≤2. The multivariate analysis showed that the prostate volume (RR, 1.34; 95% CI 1.01-1.77; P=.04), having a previous biopsy (RR, 2.25; 95% CI 1.44-3.52; P<.01), age (RR, .63; 95% CI .47-.85; P<.01) and feel palpation (RR, 1.95; 95% CI 1.28-2.96; P<.01) were factors independently associated with greater pain during the procedure. CONCLUSIONS: Transrectal biopsy with local anesthesia is a relatively painless technique. Factors such as age, a previous biopsy, pain on being touched and prostate volume were associated with the presence of greater pain during the procedure.

Influence of surgical complications on kidney graft survival in recipients of simultaneous pancreas kidney transplantation.

PURPOSE: Simultaneous pancreas-kidney transplantation is the gold standard treatment for patients with end-stage renal failure secondary to insulin-dependent diabetes mellitus. This kind of transplantation is a complex operation associated with a high incidence of surgical complications and mortality risk which could influence graft survival. The aim of this study was to establish the influence of different grades of postoperative complications, classified according to Clavien-Dindo, on the rate of kidney graft loss. METHODS: We performed an observational retrospective review of all simultaneous transplantations performed between February 1989 and May 2012. Factors examined were related to recipient and donor characteristics, surgical procedures, and postoperative outcomes. For this purpose, Kaplan-Meier analyses and Cox-Regression tests are used. RESULTS: One hundred thirty-nine transplantations were performed. Complications grades I, II, and IIIa were experienced in 81 (58.3%) patients, and grades IIIb and IVa-b in 55 (39.6%). Multivariate analysis showed an influence of panel reactive antibody (hazard ratio [HR]: 10.79; P = .003), incidence of acute rejection (HR: 2.55; P = .03), and complications grouped into grades IIIb and IVa-b (HR: 3.63; P = .02). Kaplan Meier analysis showed worse kidney graft survival rate in groups grades IIIb and IVa-b compared to grades I, II, and IIIa (86.6% vs 98.7% at 1 year and 81.8% vs 97.3% at 5 years; P = .001). CONCLUSIONS: Despite being the gold standard treatment for these patients, pancreas and kidney transplantations have numerous complications which could influence the prognosis of graft kidney survival.

Determination of trichloroanisole and trichlorophenol in wineries' ambient air by passive sampling and thermal desorption-gas chromatography coupled to tandem mass spectrometry.

The present paper describes the calibration of selected passive samplers used in the quantitation of trichlorophenol and trichloroanisole in wineries' ambient air, by calculating the corresponding sampling rates. The method is based on passive sampling with sorbent tubes and involves thermal desorption-gas chromatography-triple quadrupole mass spectrometry analysis. Three commercially available sorbents were tested using sampling cartridges with a radial design instead of axial ones. The best results were found for Tenax TA™. Sampling rates (R-values) for the selected sorbents were determined. Passive sampling was also used for accurately determining the amount of compounds present in the air. Adequate correlation coefficients between the mass of the target analytes and exposure time were obtained. The proposed validated method is a useful tool for the early detection of trichloroanisole and its precursor trichlorophenol in wineries' ambient air while avoiding contamination of wine or winery facilities.

Structure, electronic properties, and aggregation behavior of hydroxylated carbon nanotubes.

We present a combined experimental and theoretical study to analyze the structure, electronic properties, and aggregation behavior of hydroxylated multiwalled carbon nanotubes (OH-MWCNT). Our MWCNTs have average diameters of ~2 nm, lengths of approximately 100-300 nm, and a hydroxyl surface coverage θ~0.1. When deposited on the air/water interface the OH-MWCNTs are partially soluble and the floating units interact and link with each other forming extended foam-like carbon networks. Surface pressure-area isotherms of the nanotube films are performed using the Langmuir balance method at different equilibration times. The films are transferred into a mica substrate and atomic force microscopy images show that the foam like structure is preserved and reveals fine details of their microstructure. Density functional theory calculations performed on model hydroxylated carbon nanotubes show that low energy atomic configurations are found when the OH groups form molecular islands on the nanotube's surface. This patchy behavior for the OH species is expected to produce nanotubes having reduced wettabilities, in line with experimental observations. OH doping yields nanotubes having small HOMO-LUMO energy gaps and generates a nanotube → OH direction for the charge transfer leading to the existence of more hole carriers in the structures. Our synthesized OH-MWCNTs might have promising applications.