Fibrin and Transforming Growth Factor Alpha Affect Prostatic Smooth Muscle Cell's Phenotype and Motility.

Smooth muscle cells (SMCs) are dynamic and transition from a contractile to a synthetic phenotype under different circumstances. Plasma factors (fibrin and transforming growth factors, TGFs) are possible components affecting SMCs differentiation and behavior. Thus, the objective of this work was to investigate how the fibrin matrix and TGFs affect SMCs differentiation and motility behavior. SMCs invaded the fibrin gel and adopted a stellate phenotype while reducing the expression of differentiation markers (Acta2, Myh11, and Smtn). At the ultrastructural level, SMCs did not assemble a basal lamina and showed numerous blebs along the entire cell surface. This transition was not associated with changes in focal adhesion kinase (FAK) content and phosphorylation status but reflected a marked change in FAK distribution in the cytoplasm. After 48 h in culture, SMCs caused an active degradation of the fibrin gel. Additionally, we tested the SMCs response to TGFs in a cell layer wound repair assay. TGFα, but not TGFß1 or TGFß3, had significantly increased motility. In conclusion, prostatic SMCs present a phenotypical transition when cultured on fibrin, adopting a micro-blebbing based motility behavior and increasing migration in response to TGFα.

Polarization, migration, and homotypical interactions among prostatic smooth muscle cells in a laminin 111-rich extracellular matrix.

Prostate cancer is a life-threatening condition worldwide. As the tumor progresses, smooth muscle cells (SMCs) become atrophic/dedifferentiated, within a series of stromal changes named stromal reaction. Here, we tested whether a laminin 111-rich extracellular matrix (Lr-ECM) could affect SMCs phenotype and differentiation status. Using time-lapse microscopy, image analyses, quantitative real-time reverse transcription polymerase chain reaction, immunohistochemistry and immunoblotting, and transmission electron microscopy, we showed that SMCs acquires a migratory behavior with a decreased expression of differentiation markers and relocation of focal adhesion kinase. SMCs set homotypic cell junctions and were active in autophagy/phagocytosis. Analysis of the migratory behavior showed that SMCs polarized and migrated toward each other, recognizing long-distance signals such as matrix tensioning. However, half of the cell population were immotile, irrespective of the nearest neighbor distance, suggesting they do not engage in productive interactions, possibly as a result of back-to-back positioning. In conclusion, the Lr-ECM, mimics the effects of the proliferating and infiltrating tumor epithelium, causing SMCs phenotypical change similar to that observed in the stromal reaction, in addition to a hitherto undescribed, stereotyped pattern of cell motility resulting from cell polarization.

Design of chitosan-based particle systems: A review of the physicochemical foundations for tailored properties.

Chitosan-based particles are widely proposed as biocompatible drug delivery systems with mucoadhesive and permeation enhancing properties. However, strategies on how to modulate the intended biological responses are still scarce. Considering that particle properties affect the biological outcome, the rational design of the synthesis variables should be proposed to engineer drug delivery systems with improved biological performance. The purpose of this review is to establish a deeper understanding of possible correlations between these variables and the particle properties from theoretical and experimental perspectives. The fundamental physicochemical knowledge of chitosan-based polyelectrolyte complexation and surface modification is discussed focusing on chitosan-TPP, polyelectrolyte complexes, and chitosan-surface modified PLGA or lipid particles. A set of design considerations is proposed to enable future investigation in the development of chitosan particles with modulated properties. The approach presented here contributes to the rational design of chitosan-based particles that meet different requirements for biological activities.

Resistant starch/pectin free-standing films reinforced with nanocellulose intended for colonic methotrexate release.

Although resistant starch/pectin (RS/P) films have previously displayed suitable properties for colon-specific drug delivery, nanocomposite films were developed aiming to enhance physicochemical, thermal, mechanical and barrier properties, as well as the low oral bioavailability of methotrexate (MTX). FEG-SEM micrographs of nanocomposite films showed different interaction patterns occurring among nanocellulose and RS/P. The nanofiller addition led to an increase in the thermal stability, probably due to its interaction with RS crystalline double helices. Results also displayed an improvement of the puncture strength, while barrier properties revealed a low water vapor permeability. Ex vivo bioadhesion test displayed the nanocomposites films to interact strongly with porcine gastrointestinal mucosa. In vitro drug release studies showed that the films developed enhanced the drug dissolution rates with approximately 80% of MTX release in 150min, suggesting the potential of these materials as a poor solubility drugs carrier, which constitutes an important tool for enhancing oral bioavailability.

Expression of laminin-5 γ2 chain in cutaneous pseudocarcinomatous hyperplasia.

BACKGROUND: Since the use of laminin-5 as a marker of invasiveness has been proposed by several authors, our objective was to compare the expression of this protein in pseudocarcinomatous hyperplasia and squamous cell carcinoma (SCC). METHODS: Sixty-four paraffin-embedded skin biopsy samples with diagnosis of epidermal hyperplasia (non-pseudocarcinomatous), pseudocarcinomatous hyperplasia, actinic keratosis/carcinoma in situ, microinvasive and frankly invasive SCC were obtained for immunohistochemical study. RESULTS: Adjacent normal epithelium and epidermal hyperplasia (non-pseudocarcinomatous) showed no staining. In pseudocarcinomatous hyperplasia, laminin-5 was positive, at least focally, in 14 of 16 (87.5%) samples and was concentrated in peripheral cells of elongated rete pegs and in migrating cells in dermis. In samples of microinvasive carcinoma (n = 7), the expression was observed in all cases and was concentrated in the leading edge of the tumor. All cases (n = 21) of frankly invasive SCC showed cells expressing laminin-5, at least focally. Well-differentiated areas of the tumor presented a pattern of expression in peripheral cells of tumor nests while a diffuse pattern of expression was observed in less differentiated areas. CONCLUSION: We showed that cytoplasmic laminin-5 expression should not be used as a criterion of malignancy and is not useful in distinguishing pseudocarcinomatous hyperplasia from microinvasive and well-differentiated SCC.