Prolonged and Controllable Release of Doxorubicin Hydrochloride from the Composite Electrospun Poly(ε-Caprolactone)/Polyvinylpyrrolidone Scaffolds.

Burst release, typical for the drug-loaded electrospun poly(ε-caprolactone) (PCL) scaffolds is unfavorable in case of cytostatics due to the toxic levels reached during the initial implantation period. In the present short communication, we report an unexpected ability of the composite scaffolds made of PCL and water-soluble polyvinylpyrrolidone (PVP) to provide long-term release of widely used anti-cancer drug doxorubicin hydrochloride (DOX-HCl). That effect was observed for electrospun DOX-HCl-loaded composite scaffolds based on PCL and PVP with various mass ratios (100/0, 95/5, 90/10, 75/25 and 50/50). After the morphology and water contact angle studies, it was concluded that PVP content has no effect on the average fiber diameter, while PVP content higher 10 wt. % changes the hydrophobic character of the scaffolds surface (water contact angle of 123.9 ± 3.5°) to superhydrophilic (water contact angle of 0°). Despite the dramatic change in water wettability, by high performance liquid chromatography (HPLC), it was revealed that the PVP content in the scaffolds reduces the DOX-HCl release rate under short (first hours) and long-term (during 1 month) exposure to phosphate buffer saline (PBS). These results are in good agreement with in vitro studies, in which the viability of HeLa cervical cancer cells was higher after 24 h of culture with scaffolds with high PVP content.

Electrospun Poly-L-Lactic Acid Scaffolds Surface-Modified via Reactive Magnetron Sputtering Using Different Mixing Ratios of Nitrogen and Xenon.

Controlled regeneration processes involving tissue growth using the surface and structure of scaffolds, are actively used in tissue engineering. Reactive magnetron sputtering is a versatile surface modification method of both metal and polymer substrates, as the properties of the formed coatings can be modified in a wide range by changing the process parameters. In magnetron sputtering, the working gas and its composition have an influence on the chemical composition and physical characteristics of the obtained coatings. However, there are no studies addressing the influence of the nitrogen/xenon gas mixture ratio in direct current magnetron sputtering on the deposition rate, physicochemical and in vitro properties of surface-modified biocompatible poly-L-lactic acid scaffolds. In this study, the application of mixtures of nitrogen and xenon in various ratios is demonstrated to modify the surface of non-woven poly-L-lactic acid scaffolds by direct current magnetron sputtering of a titanium target. It has been found that the magnetron sputtering parameters chosen do not negatively influence the morphology of the prepared scaffolds, but increase the hydrophilicity. Moreover, quantitative spectroscopic analysis results indicate that the formed coatings are primarily composed of titanium oxide and titanium oxynitride compounds and is dependent on the gas mixture ratio only to a certain extent. Atomic force microscopy investigations of the roughness of the fibers of the electrospun scaffolds and the thickness of the coatings formed on them show that the considerable variations observed in the intrinsic fiber reliefs are due to the formation of a fine layer on the fiber surfaces. The observed decrease in roughness after plasma modification is due to temperature and radiation effects of the plasma. In vitro experiments with human osteosarcoma cells show that the scaffolds investigated here have no cytotoxic effect on these cells. The cells adhere and proliferate well on each of the surface-modified electrospun scaffolds, with stimulation of cell differentiation in the osteogenic direction.

Surface Modification of Additively Fabricated Titanium-Based Implants by Means of Bioactive Micro-Arc Oxidation Coatings for Bone Replacement.

In this work, the micro-arc oxidation method is used to fabricate surface-modified complex-structured titanium implant coatings to improve biocompatibility. Depending on the utilized electrolyte solution and micro-arc oxidation process parameters, three different types of coatings (one of them-oxide, another two-calcium phosphates) were obtained, differing in their coating thickness, crystallite phase composition and, thus, with a significantly different biocompatibility. An analytical approach based on X-ray computed tomography utilizing software-aided coating recognition is employed in this work to reveal their structural uniformity. Electrochemical studies prove that the coatings exhibit varying levels of corrosion protection. In vitro and in vivo experiments of the three different micro-arc oxidation coatings prove high biocompatibility towards adult stem cells (investigation of cell adhesion, proliferation and osteogenic differentiation), as well as in vivo biocompatibility (including histological analysis). These results demonstrate superior biological properties compared to unmodified titanium surfaces. The ratio of calcium and phosphorus in coatings, as well as their phase composition, have a great influence on the biological response of the coatings.

Tumor-associated macrophages in human breast cancer produce new monocyte attracting and pro-angiogenic factor YKL-39 indicative for increased metastasis after neoadjuvant chemotherapy.

In breast cancer, the tumor microenvironment plays a critical role in the tumor progression and responses to therapy. Tumor-associated macrophages (TAMs) are major innate immune cells in tumor microenvironment that regulate intratumoral immunity and angiogenesis by secretion of cytokines, growth factors as well as chitinase-like proteins (CLPs), that combine properties of cytokines and growth factors. YKL-39 is a chitinase-like protein found in human and absent in rodents, and its expression in TAMs and role in breast cancer progression was not studied to date. Here for the first time we demonstrate that YKL-39 is expressed on TAMs, predominantly positive for stabilin-1, but not by malignant cells or other stromal cells in human breast cancer. TGF-beta in combination with IL-4, but not IL-4 alone was responsible of the stimulation of the production of YKL-39 in human primary macrophages. Mechanistically, stabilin-1 directly interacted with YKL-39 and acted as sorting receptor for targeting YKL-39 into the secretory pathway. Functionally, purified YKL-39 acted as a strong chemotactic factor for primary human monocytes, and induced angiogenesis in vitro. Elevated levels of YKL-39 expression in tumors after neoadjuvant chemotherapy (NAC) were predictive for increased risk of distant metastasis and for poor response to NAC in patients with nonspecific invasive breast carcinoma. Our findings suggest YKL-39 as a novel therapeutic target, and blocking of its activity can be combined with NAC in order to reduce the risk of metastasis in breast cancer patients.

Clinically relevant morphological structures in breast cancer represent transcriptionally distinct tumor cell populations with varied degrees of epithelial-mesenchymal transition and CD44+CD24- stemness.

Intratumor morphological heterogeneity in breast cancer is represented by different morphological structures (tubular, alveolar, solid, trabecular, and discrete) and contributes to poor prognosis; however, the mechanisms involved remain unclear. In this study, we performed 3D imaging, laser microdissection-assisted array comparative genomic hybridization and gene expression microarray analysis of different morphological structures and examined their association with the standard immunohistochemistry scorings and CD44+CD24- cancer stem cells. We found that the intratumor morphological heterogeneity is not associated with chromosomal aberrations. By contrast, morphological structures were characterized by specific gene expression profiles and signaling pathways and significantly differed in progesterone receptor and Ki-67 expression. Most importantly, we observed significant differences between structures in the number of expressed genes of the epithelial and mesenchymal phenotypes and the association with cancer invasion pathways. Tubular (tube-shaped) and alveolar (spheroid-shaped) structures were transcriptionally similar and demonstrated co-expression of epithelial and mesenchymal markers. Solid (large shapeless) structures retained epithelial features but demonstrated an increase in mesenchymal traits and collective cell migration hallmarks. Mesenchymal genes and cancer invasion pathways, as well as Ki-67 expression, were enriched in trabecular (one/two rows of tumor cells) and discrete groups (single cells and/or arrangements of 2-5 cells). Surprisingly, the number of CD44+CD24- cells was found to be the lowest in discrete groups and the highest in alveolar and solid structures. Overall, our findings indicate the association of intratumor morphological heterogeneity in breast cancer with the epithelial-mesenchymal transition and CD44+CD24- stemness and the appeal of this heterogeneity as a model for the study of cancer invasion.

CD68+, but not stabilin-1+ tumor associated macrophages in gaps of ductal tumor structures negatively correlate with the lymphatic metastasis in human breast cancer.

Tumor associated macrophages (TAM) support tumor growth and metastasis in several animal models of breast cancer, and TAM amount is predictive for efficient tumor growth and metastatic spread via blood circulation. However, limited information is available about intratumoral TAM heterogeneity and functional role of TAM subpopulations in tumor progression. The aim of our study was to examine correlation of TAM presence in various morphological segments of human breast cancer with clinical parameters. Thirty six female patients with nonspecific invasive breast cancer T1-4N0-3M0 were included in the study. Morphological examination was performed using Carl Zeiss Axio Lab.A1 and MiraxMidiZeiss. Immunohistochemical and immunofluorescence/confocal microcopy analysis was used to detect CD68 and stabilin-1 in 5 different tumor segments: (1) areas with soft fibrous stroma; (2) areas with coarse fibrous stroma; (3) areas of maximum stromal-and-parenchymal relationship; (4) parenchymal elements; (5) gaps of ductal tumor structures. The highest expression of CD68 was in areas with soft fibrous stroma or areas of maximum stromal-and-parenchymal relationship (79%). The lowest expression of CD68 was in areas with coarse fiber stroma (23%). Inverse correlation of tumor size and expression of CD68 in gaps of tubular tumor structures was found (R=-0.67; p=0.02). In case of the lymph node metastases the average score of CD68 expression in ductal gaps tumor structures was lower (1.4±0.5) compared to negative lymph nodes case (3.1±1.0; F=10.9; p=0.007). Confocal microscopy identified 3 phenotypes of TAM: CD68+/stabilin-1-; CD68+/stabilin-1+ (over 50%); and CD68-/stabilin-1+. However, expression of stabilin-1 did not correlate with lymph node metastasis. We concluded, that increased amount of CD68+TAM in gaps of ductal tumor structures is protective against metastatic spread in regional lymph nodes.

Tumor-associated macrophages in human breast cancer parenchyma negatively correlate with lymphatic metastasis after neoadjuvant chemotherapy.

Breast cancer is the leading cause of cancer death in women worldwide with high morbidity and mortality. Tumor-associated macrophages (TAM) are major innate immune cells in the tumor microenvironment controlling primary tumor growth and metastasis. Neoadjuvant chemotherapy (NACT) is a conventional pre-operative treatment for breast cancer. In the present study we examined the distribution of TAM in five distinct intratumoral morphological compartments of human breast cancer and their correlation with clinical parameters after NACT. Our data indicated that CD68+ but not stabilin-1+ TAM in areas with parenchymal elements negatively correlate with lymphatic metastasis after NACT. However, in cases where lymphatic metastases were detected (28 out of 50 analyzed samples) both amount of CD68+ and stabilin-1+ macrophages in the areas with coarse fibrous stroma directly correlated with the number of positive lymph nodes. In patients with complete response to the preoperative NACT the average score of CD68 expression in the areas with coarse fibrous stroma was lower compared with cases of a partial response and stable disease. We concluded that function of TAM after NACT depends on their intratumoral localization and local tumor microenvironment which plays an important role in polarization of macrophages towards tumor-suppressive or tumor-supportive types.

Intratumoral heterogeneity of macrophages and fibroblasts in breast cancer is associated with the morphological diversity of tumor cells and contributes to lymph node metastasis.

Recent studies have highlighted the heterogeneity of the tumor microenvironment (ME) and the importance of its analysis to the understanding of its impact on clinical outcomes. In this study, we aimed to analyze the intratumoral distribution of macrophages and fibroblasts in breast cancer (BC) based on the morphological diversity of tumor cells (tubular, alveolar, solid, trabecular and discrete structures) and the clinicopathological parameters of the disease. Thirty-six patients with invasive breast carcinoma of no special type were included in the study. The distribution of macrophages and fibroblasts in the MEs of different morphological structures was assessed using laser microdissection-assisted quantitative RT-PCR analysis of marker genes and double immunofluorescence staining for the CD68, RS1, aSMA, and FAP proteins. Gene expression microarrays were used to determine the expression of genes involved in the regulation of macrophage and fibroblast phenotypes in different morphological structures. We found that different macrophage and fibroblast subpopulations were simultaneously observed in the MEs of morphologically distinct structures but that the frequency of their detection and number of cells detected varied significantly among these structures. In particular, macrophages and fibroblasts were more frequently detected in the ME of solid structures and were rarely observed in tubular structures. A high number of CD68+RS1+ macrophages in the ME of solid structures was found to be associated with an increased frequency of lymph node metastasis in luminal B HER2- BC. In contrast, in luminal B HER2+ BC, lymph node involvement was related to the high representation of aSMA+FAP+ fibroblasts around trabecular structures. Morphologically distinct structures differed in the mechanisms regulating the macrophage and fibroblast phenotypes. The highest number of overexpressed genes controlling macrophage and fibroblast functions was observed in discrete groups of tumor cells, and the lowest number was observed in alveolar and solid structures. Taken together, our findings indicate the heterogeneous distribution of macrophages and fibroblasts in breast tumors and its close relation to the intratumoral morphological diversity of BC and contribution to lymph node metastasis.

Different patterns of allelic imbalance in sporadic tumors and tumors associated with long-term exposure to gamma-radiation.

The study aimed to reveal cancer related mutations in DNA repair and cell cycle genes associated with chronic occupational exposure to gamma-radiation in personnel of the Siberian Group of Chemical Enterprises (SGCE). Mutations were analyzed by comparing genotypes of malignant tumors and matched normal tissues of 255 cancer patients including 98 exposed to external gamma-radiation (mean dose 128.1±150.5mSv). Also a genetic association analysis was carried out in a sample of 149 cancer patients and 908 healthy controls occupationally exposed to gamma-radiation (153.2±204.6mSv and 150.5±211.2mSv, respectively). Eight SNPs of genes of DNA excision repair were genotyped (rs13181, rs1052133, rs1042522, rs2305427, rs4244285, rs1045642, rs1805419 and rs1801133). The mutation profiles in heterozygous loci for selected SNP were different between sporadic tumors and tumors in patients exposed to radiation. In sporadic tumors, heterozygous genotype Arg/Pro of the rs1042522 SNP mutated into Arg/0 in 15 cases (9.6%) and 0/Pro in 14 cases (8.9%). The genotype Lys/Gln of the rs13181 SNP mutated into Lys/0 and 0/Gln in 9 and 4 cases, respectively. In tumors of patients exposed to low-level radiation, the rs1042522 Arg/0 mutated genotype was found in 12 cases (12.1%), while in 2 cases (2%) 0/Pro mutation was observed. Finally, the rs13181 0/Gln mutated genotype was observed in 15 cases (16,5%) . Thus, our study showed the difference in patterns of allelic imbalance in tumors appeared under low-level radiation exposure and spontaneous tumors for selected SNPs. This suggests different mechanisms of inactivation of heterozygous genotypes in sporadic and radiation-induced tumors.

Cellular effects of low-intensity pulsed ultrasound and X-irradiation in combination in two human leukaemia cell lines.

Previously, we have shown that a combination between X-irradiation and low-intensity pulsed ultrasound (US) could synergistically suppress cell survival post exposure (Buldakov et al., 2014). In this study, the cellular effects underlying the enhanced cell killing are investigated. U937 and Molt-4 cell lines were exposed to 1.0 MHz US with 50% duty factor at 0.3 W/cm(2) and pulsed at 1, 5 and 10 Hz immediately after exposure to X-rays at 0, 0.5, 2.5 and 5 Gy. The cells were assayed at different time points to depict the major cellular events that culminated in cell death. For instance, membrane damage and cell lysis were estimated immediately following exposure and 24 h later. Intracellular reactive oxygen species (ROS) were also determined flow cytometrically after treatment. Moreover, the extent of DNA damage and cell cycle progression were determined at 6 and 24 h, respectively. Despite the general trend for synergism, there was a disproportionation of mediating factors depending on the cell type and its specific biological makeup. Immediately, US could induce appreciable necrotic cell death through extensive membrane damage in U937 but induced cell lysis in Molt-4 cells. ROS might have contributed to cell killing in Molt-4 but not in U937 cells. Although both of the physical modalities are significantly DNA-damaging alone, no additional damage was observed in combination. Moreover, override in some arrested cell cycle phases was also observed following combination. Collectively, the interaction between X-rays and US seems to depend mainly on the acoustic environment determined by the setup and this might explain the contradictory data among reports.

Low-intensity pulsed ultrasound enhances cell killing induced by X-irradiation.

To determine the effect of pulsed ultrasound (US) on radiation-induced cell killing, U937 and Molt-4 cell lines were exposed to 1.0 MHz US with 50% of duty factor at 0.3 W/cm(2) and pulsed at 1 Hz immediately after exposure to X-rays at 0, 0.5, 2.5 and 5 Gy. The cells were assayed 24 h after the treatments. The result showed significant enhancement of cell killing in the combined treatments. However, the ratio of apoptotic cells induced either by X-rays or US alone did not significantly change. These findings suggest that pulsed US can enhance the anticancer effect of X-irradiation due to US streaming under non-inertial cavitational condition. This combined treatment can potentially enhance the therapeutic effect of radiation therapy.

Expression of cyclophilin A in gastric adenocarcinoma patients and its inverse association with local relapses and distant metastasis.

The aim of this study was to identify new protein markers of the intestinal and diffuse type gastric adenocarcinoma and to determine their relation to local relapses and distant metastasis. Using two-dimensional gel electrophoresis, we searched for proteins that are overexpressed in the intestinal and/or diffuse type gastric adenocarcinoma, as compared to matched normal mucosa samples with further change confirmation by Western blot. Expression of the selected proteins was further assessed by immunohistocemistry in a large panel of gastric adenocarcinoma with various clinicopathological features. Expression level of cyclophilin A measured with western blot appeared to be increased on average ten times in 63 % of gastric adenocarcinoma vs. paired samples of normal mucosa. The frequency of immunihistochemistry detected cyclophilin A protein expression was found to be equal in tumor of both histotypes, but staining intensity was higher in intestinal versus diffuse types of gastric adenocarcinoma. cyclophilin A protein expression appeared to be lower in deeply invading glandular and cribriform structures of intestinal tumors, as well as in discretely placed groups of the intestinal tumor cells. Local relapses as well as distant metastases registered within 3 year follow up were observed to occur much less frequently in patients with positive cyclophilin A immunostaining in gastric tumors. Analysis of cyclophilin A expression has a potential value for prognosis of gastric adenocarcinoma recurrence and distant metastasis.

Static hyperpolarizability of the van der Waals complex CH(4)-N(2).

The static first hyperpolarizability of the van der Waals CH(4)-N(2) complex was calculated. The calculations were carried out in the approximation of the rigid interacting molecules for a broad range of intermolecular separations (R = 6-40 a(0)) and for six configurations at CCSD(T) level of theory using the correlation consistent aug-cc-pVTZ basis set with the basis set superposition error correction. It was shown that the long-range classical approximation, including the terms up to R(-6), is in a good agreement with ab initio calculations for R > 11 a(0). It was found out that for the family of most stable configurations of the complex, the first hyperpolarizability invariants practically do not change (the changes are less than 0.1%). Under forming the stable van der Waals CH(4)-N(2) complex, the intensity and degree of depolarization of the hyper-Rayleigh scattering are noticeable decreased (by ∼10%) to be compared with the free CH(4) and N(2) molecules.

Theoretical investigation of the ethylene dimer: interaction energy and dipole moment.

The interaction potential energy and the interaction-induced dipole moment surfaces of the van der Waals C(2)H(4)-C(2)H(4) complex has been calculated for a broad range of intermolecular separations and configurations in the approximation of rigid interacting molecules. The calculations have been carried out using high-level ab initio theory with the aug-cc-pVTZ basis set and within the framework of the analytical description of long-range interactions between ethylene molecules. Binding energy for the most stable configuration of the C(2)H(4)-C(2)H(4) complex was calculated at the CCSD(T)/CBS level of theory. The harmonic fundamental vibrational frequencies for this complex were calculated at the MP2 level of theory.

Dipole moment surface of the van der Waals complex CH4-N2.

The interaction-induced dipole moment surface of the van der Waals CH(4)-N(2) complex has been calculated for a broad range of intermolecular separations R and configurations in the approximation of the rigid interacting molecules at the MP2 and CCSD(T) levels of theory using the correlation-consistent aug-cc-pVTZ basis set with the basis set superposition error correction. The simple model to account for the exchange effects in the range of small overlap of the electron shells of interacting molecules and the induction and dispersion interactions for large R has been suggested. This model allows describing the dipole moment of van der Waals complexes in analytical form both for large R, where induction and dispersion have the key role, and for smaller R including whole ranges of their potential wells, where the exchange effects are important. The proposed model was tested on a number of configurations of the CH(4)-N(2) complex and was applied for the analytical description of the dipole moment surface for the family of the most stable configurations of the CH(4)-N(2) complex.

Static polarizability surfaces of the van der Waals complex CH4-N2.

The static polarizability surfaces of the van der Waals complex CH(4)-N(2) have been calculated for a broad range of intermolecular separations and configurations in the approximation of rigid interacting molecules. The calculations have been carried out at the CCSD(T) and MP2 levels of the theory using the aug-cc-pVTZ basis set with the BSSE correction and within the framework of the classical long-range multipolar induction and dispersion interactions. It was shown that the results of analytical polarizability calculations for the CH(4)-N(2) complex are in a good agreement with the ab initio polarizabilities in the outer part of the van der Waals well on the complex potential surface. Ab initio calculations of the polarizability tensor invariants for the complex being in the most stable configurations were carried out. The change in the polarizability of CH(4)-N(2) due to the deformation of the CH(4) and N(2) monomers at the formation of the complex was estimated. In the framework of the analytical approach the polarizability functions alpha(ii)(R) of the free oriented interacting molecules CH(4) and N(2) were calculated.

Modulation control over ultrasound-mediated gene delivery: evaluating the importance of standing waves.

Low modulation frequencies from 0.5 to 100Hz were shown to alter the characteristics of the ultrasound field producing solution agitation (<5Hz; region of "ultrasound streaming" prevalence) or stagnancy (>5Hz; region of standing waves establishment) (Buldakov et al., Ultrason. Sonochem., 2009). In this study, the same conditions were used to depict the changes in exogenous DNA delivery in these regions. The luciferase expression data revealed that lower modulations were more capable of enhancing delivery at the expense of viability. On the contrary, the viability was conserved at higher modulations whereas delivery was found to be null. Cavitational activity and acoustic streaming were the effecters beyond the observed pattern and delivery enhancement was shown to be mediated mainly through sonopermeation. To promote transfection, the addition of calcium ions or an echo contrast agent (Levovist((R))) was proposed. Depending on the mechanism involved in each approach, differential enhancement was observed in both regions and at the interim zone (5Hz). In both cases, enhancement in standing waves field was significant reaching 16.0 and 3.3 folds increase, respectively. Therefore, it is concluded that although the establishment of standing waves is not the only prerequisite for high transfection rates, yet, it is a key element in optimization when other factors such as proximity and cavitation are considered.

Theoretical investigation of the potential energy surface of the van der Waals complex CH4-N2.

The interaction potential energy surface of the van der Waals CH(4)-N(2) complex has been calculated for a broad range of intermolecular separations and configurations in the approximation of rigid interacting molecules at the CCSD(T) and MP2 levels of theory using the correlation consistent aug-cc-pVTZ basis set. The BSSE correction was taken into account for all the calculations. The most stable configurations of the complex were found. Binding energies were calculated in the CBS limit with accounting for the molecular deformations. The harmonic and anharmonic fundamental vibrational frequencies and rotational constants for the ground and first excited vibrational states were calculated for the most stable configurations at the MP2 level of theory with BSSE correction. Fitting parameters were found for the most stable configuration for the Lennard-Jones and Esposti-Werner potentials.

Influence of changing pulse repetition frequency on chemical and biological effects induced by low-intensity ultrasound in vitro.

This study was undertaken to examine ultrasound (US) mechanisms and their impact on chemical and biological effects in vitro as a function of changing pulse repetition frequency (PRF) from 0.5 to 100Hz using a 1MHz-generator at low-intensities and 50% duty factor (DF). The presence of inertial cavitation was detected by electron paramagnetic resonance (EPR) spin-trapping of hydroxyl radicals resulting from sonolysis of water. Non-cavitational effects were evaluated by studying the extent of sucrose hydrolysis measured by UV spectrophotometry. Biological effects were assessed by measuring the extent of cell killing and apoptosis induction in U937 cells using Trypan blue dye exclusion test and flow cytometry, respectively. The results indicate significant PRF dependence with respect to hydroxyl radical formation, cell killing and apoptosis induction. The lowest free radical formation and cell killing and the highest cell viability were found at 5Hz (100ms pulse duration). On the other hand, no correlation was found between sucrose hydrolysis and PRF. To our knowledge, this is the first report to be devoted to study the impact of low PRFs at low-intensities on US-induced chemical and biological effects and the mechanisms involved. This study has introduced the role of "US streaming" (convection); a forgotten factor in optimization studies, and explored its importance in comparison to standing waves.