Poly(allylamine)-tripolyphosphate Ionic Assemblies as Nanocarriers: Friend or Foe?

Designing effective drug nanocarriers that are easy to synthesize, robust, and nontoxic is a significant challenge in nanomedicine. Polyamine-multivalent molecule nanocomplexes are promising drug carriers due to their simple and all-aqueous manufacturing process. However, these systems can present issues of colloidal instability over time and cellular toxicity due to the cationic polymer. In this study, we finely modulate the formation parameters of poly(allylamine-tripolyphosphate) complexes to jointly optimize the robustness and safety. Polyallylamine was ionically assembled with tripolyphosphate anions to form liquid-like nanocomplexes with a size of around 200 nm and a zeta potential of -30 mV. We found that nanocomplexes exhibit tremendous long-term stability (9 months of storage) in colloidal dispersion and that they are suitable as protein-loading agents. Moreover, the formation of nanocomplexes induced by tripolyphosphate anions produces a switch-off in the toxicity of the system by altering the overall charge from positive to negative. In addition, we demonstrate that nanocomplexes can be internalized by bone-marrow-derived macrophage cells. Altogether, these nanocomplexes have attractive and promising properties as delivery nanoplatforms for potential therapies based on the immune system activation.

Redox responsive poly(allylamine)/eudragit S-100 nanoparticles for dual drug delivery in colorectal cancer.

Herein, we report redox responsive, colon cancer targeting poly(allylamine) (PA)/eudragit S-100 (EU) nanoparticles (PAEU NPs) (≈59 nm). These disulfide crosslinked PAEU NPs are developed via air oxidation of thiolated PA and thiolated EU, eliminating the need of any external crosslinking agent for dual drug delivery. PAEU NPs can effectively encapsulate both hydrophilic doxorubicin (DOX) and hydrophobic curcumin (Cur) drug with ≈85 % and ≈97 % encapsulation efficiency respectively. Here, the combination of drugs having different anticancer mechanism offers the possibility of developing nanosystem with enhanced anticancer efficacy. The developed PAEU NPs show good colloidal stability and low drug release under physiological conditions, while high DOX (≈98 %) and Cur (≈93 %) release is observed in reducing environment (10 mM GSH). Further, DOX and Cur loaded PAEU NPs exhibit higher cancer cell killing efficiency as compared to individual free drugs. In vivo biodistribution studies with Balb/C mice display the retention of PAEU NPs in the colon region up to 24 h presenting the developed approach as an efficient way for colorectal cancer therapy.

The Effect of Amino-Phosphate Interactions on the Biosensing Performance of Enzymatic Graphene Field-Effect Transistors.

The interaction between polyamines and phosphate species is found in a wide range of biological and abiotic systems, yielding crucial consequences that range from the formation of supramolecular colloids to structure determination. In this work, the occurrence of phosphate-amino interactions is evidenced from changes in the electronic response of graphene field effect transistors (gFETs). First, the surface of the transistors is modified with poly(allylamine), and the effect of phosphate binding on the transfer characteristics is interpreted in terms of its impact on the surface charge density. The electronic response of the polyamine-functionalized gFETs is shown to be sensitive to the presence of different phosphate anions, such as orthophosphate, adenosine triphosphate, and tripolyphosphate, and a simple binding model is developed to explain the dependence of the shift of the Dirac point potential on the phosphate species concentration. Afterward, the impact of phosphate-amino interactions on the immobilization of enzymes to polyamine-modified graphene surfaces is investigated, and a decrease in the amount of anchored enzyme as the phosphate concentration increases is found. Finally, multilayer polyamine-urease biosensors are fabricated while increasing the phosphate concentration in the enzyme solution, and the sensing properties of the gFETs toward urea are evaluated. It is found that the presence of simple phosphate anions alters the nanoarchitecture of the polyelectrolyte-urease assemblies, with direct implications on urea sensing.

Development, optimization and characterization of nanoemulsion loaded with clove oil-naftifine antifungal for the management of tinea.

Tinea is a common superficial infection caused by keratinophylic fungi called dermatophytes. The objective of the current investigation was to develop and optimize a self-nanoemulsion drug delivery system (SENDDs) using clove oil loaded with naftifine (NF). Clove oil possesses good anti-inflammatory and antifungal properties that can support naftifine action. Box-Behnken designs were used to prepare plain and naftifine loaded SENDDs. The plain SENDDs were evaluated for their globule size. The medicated formulations (NF-CO-SENDDs) were characterized by measuring their globular size, ex vivo % NF permeated, level of interleukin-31 in rats, and antifungal activity. The optimum clove oil level was found to be 10-17%, while NF-CO-SENDDs formulations displayed globular sizes ranging from 119 to 310 nm. The statistical design confirmed the synergistic effect of clove oil and NF in the treatment of fungal infections, confirming that the anti-inflammatory effect of clove oil can counteract the side effects of NF. The optimized formulation composed of 14% clove oil, 12.5 mg Naftifine, and prepared with an Smix ratio equaling 3:1, exhibited good antifungal and anti-inflammatory activity, achieving up to 2-, 3-, 5.75-, and 2.74-fold increases in the amount of permeated NF, steady-state flux, permeability, and diffusion coefficients, respectively, compared with a commercial product. Moreover, the optimum formulation revealed an adequate zeta potential value of 28.31 ± 1.37 mV and showed reasonable stability with no or mild signs of skin sensitivity. Therefore, the designed nanoemulsions containing a combination of clove oil and naftifine could be considered promising delivery systems for the treatment of tinea.

Effect of Poly(allylamine) Molecular Weight on Drug Loading and Release Abilities of Nano-Aggregates for Potential in Cancer Nanomedicine.

Poly(allylamine) graft polymers have been shown to hold potential as drug delivery vehicles and complexation agents for biological molecules such as insulin. The nanoparticles formed upon aggregation or complexation allow for enhanced cellular trafficking resulting in enhanced efficacy. Multiple reports have shown the ease of synthesis and reliability of these graft polymers, however, little investigation into the effect of the molecular weight of the homopolymer poly(allylamine) has been carried out. In this work we synthesized a range of oxadiazole grafted poly(allylamine) derivatives of varied molecular weight (15, 17.5, 120 & 900 kDa) set at a 5% polymer:oxadiazole mole grafting. The effect of molecular weight on the size, critical aggregation concentration and drug loading/release was evaluated in model drugs before loading the optimal formulation with doxorubicin and carrying out a preliminary cytotoxicity study. In line with other cationic polymers, the larger poly(allylamine) amphiphilic derivatives resulted in greater drug loading, however, the particle size increased whilst drug loading dramatically decreased, which for cancer nanomedicine could be a barrier for pharmaceutical use.

Replication of a Tissue Microenvironment by Thermal Scanning Probe Lithography.

Thermal scanning probe lithography (t-SPL) is a nanofabrication technique in which an immobilized thermolabile resist, such as polyphthalaldehyde (PPA), is locally vaporized by a heated atomic force microscope tip. Compared with other nanofabrication techniques, such as soft lithography and nanoimprinting lithography, t-SPL is more efficient and convenient as it does not involve time-consuming mask productions or complicated etching procedures, making it a promising candidate technique for the fast prototyping of nanoscale topographies for biological studies. Here, we established the direct use of PPA-coated surfaces as a cell culture substrate. We showed that PPA is biocompatible and that the deposition of allylamine by plasma polymerization on a silicon wafer before PPA coating can stabilize the immobilization of PPA in aqueous solutions. When seeded on PPA-coated surfaces, human mesenchymal stem cells (MSC) adhered, spread, and proliferated in a manner indistinguishable from cells cultured on glass surfaces. This allowed us to subsequently use t-SPL to generate nanotopographies for cell culture experiments. As a proof of concept, we analyzed the surface topography of bovine tendon sections, previously shown to induce morphogenesis and differentiation of MSC, by means of atomic force microscopy, and then "wrote" topographical data on PPA by means of t-SPL. The resulting substrate, matching the native tissue topography on the nanoscale, was directly used for MSC culture. The t-SPL substrate induced similar changes in cell morphology and focal adhesion formation in the MSC compared to native tendon sections, suggesting that t-SPL can rapidly generate cell culture substrates with complex and spatially accurate topographical signals. This technique may greatly accelerate the prototyping of models for the study of cell-matrix interactions.

Inhibition of semicarbazide-sensitive amine oxidase reduces atherosclerosis in apolipoprotein E-deficient mice.

Inflammation, oxidative stress, and formation of advanced glycated end products (AGEs) and advanced lipoxidation end products (ALEs) are important for atherosclerosis. Vascular adhesion protein-1 (VAP-1) participates in inflammation and has semicarbazide-sensitive amine oxidase (SSAO) activity, which catalyzes oxidative deamination to produce hydrogen peroxide and aldehydes, leading to generation of AGEs and ALEs. However, the effect of VAP-1/SSAO inhibition on atherosclerosis remains controversial, and no studies used coronary angiography to evaluate if plasma VAP-1/SSAO is a biomarker for coronary artery disease (CAD). Here, we examined if plasma VAP-1/SSAO is a biomarker for CAD diagnosed by coronary angiography in humans and investigated the effect of VAP-1/SSAO inhibition by a specific inhibitor PXS-4728A on atherosclerosis in cell and animal models. In the study, VAP-1/SSAO expression was increased in plaques in humans and in apolipoprotein E (ApoE)-deficient mice, and colocalized with vascular endothelial cells and smooth muscle cells (SMCs). Patients with CAD had higher plasma VAP-1/SSAO than those without CAD. Plasma VAP-1/SSAO was positively associated with the extent of CAD. In ApoE-deficient mice, VAP-1/SSAO inhibition reduced atheroma and decreased oxidative stress. VAP-1/SSAO inhibition attenuated the expression of adhesion molecules, chemoattractant proteins, and proinflammatory cytokines in the aorta, and suppressed monocyte adhesion and transmigration across human umbilical vein endothelial cells. Consequently, the expression of markers for macrophage recruitment and activation in plaques was decreased by VAP-1/SSAO inhibition. Besides, VAP-1/SSAO inhibition suppressed proliferation and migration of A7r5 SMC. Our data suggest that plasma VAP-1/SSAO is a novel biomarker for the presence and the extent of CAD in humans. VAP-1/SSAO inhibition by PXS-4728A is a potential treatment for atherosclerosis.

Efficacy of combination of ozonated water with oil for treatment of tinea pedis.

OBJECTIVE: To evaluate efficacy of combined therapy with ozonated water and oil on patients with tinea pedis.
 Methods: A total of 60 patients with tinea pedis were divided into 2 groups in a randomized and blinded test. Patients in a control group were treated with naftinfine hydrochloride and ketoconazole cream once a day. Patients in an ozone group were treated with ozonated water bath and then ozonated oil topical application once a day. Patients in the 2 groups were treated for 4 weeks. Clinical and laboratory data were collected for both groups at the end of the 1st week, the 2nd week, and the 4th week. The Pearson chi-square was performed to compare scores of the clinical signs and symptoms (CSS) and the mycological result between the 2 groups. Independent samples T-test was performed to compare the curative effect between the 2 groups.
 Results: After 4 weeks' treatment, 6 patients were positive in the control group determined by mycological examination while 1 patient was positive in the ozone group, with no significant difference between the 2 groups (P>0.05). Changes in CSS at the end of the 1st week, 2nd week, and 4th week were obtained and showed no significant difference between the 2 groups at the 3 different time points (P>0.05). No side effects were observed.
 Conclusion: Combination of ozonated water with oil is effective on treatment of tinea pedis and it shows no side effects.

Surface modification of polypropylene for enhanced layer-by-layer deposition of polyelectrolytes.

We have performed three distinct plasma enhanced chemical vapor deposition procedures that can be widely and consistently used in commercially available plasma systems to modify the surface of hydrocarbon-based biomaterials such as polypropylene. In particular, we have evaluated the feasibility of these procedures to provide consistent and stable charged substrates to perform layer-by-layer (LbL) coatings. Surface characterization of both plasma and LbL coatings were done using X-ray photoelectron spectroscopy, attenuated total reflection-Fourier transform infrared spectroscopy, contact angle measurements and surface staining. Results showed successful surface grafting of functional groups in all plasma procedures that led to increased hydrophilicity and uniform LbL coatings with different efficiencies. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 2078-2085, 2018.

Exploring the pH Sensitivity of Poly(allylamine) Phosphate Supramolecular Nanocarriers for Intracellular siRNA Delivery.

Silencing RNA (siRNA) technologies emerge as a promising therapeutic tool for the treatment of multiple diseases. An ideal nanocarrier (NC) for siRNAs should be stable at physiological pH and release siRNAs in acidic endosomal pH, fulfilling siRNA delivery only inside cells. Here, we show a novel application of polyamine phosphate NCs (PANs) based on their capacity to load negatively charged nucleic acids and their pH stability. PANs are fabricated by complexation of phosphate anions from phosphate buffer solution (PB) with the amine groups of poly(allylamine) hydrochloride as carriers for siRNAs. PANs are stable in a narrow pH interval, from 7 to 9, and disassemble at pH's higher than 9 and lower than 6. siRNAs are encapsulated by complexation with poly(allylamine) hydrochloride before or after PAN formation. PANs with encapsulated siRNAs are stable in cell media. Once internalized in cells following endocytic pathways, PANs disassemble at the low endosomal pH and release the siRNAs into the cytoplasm. Confocal laser scanning microscopy (CLSM) images of Rhodamine Green labeled PANs (RG-PANs) with encapsulated Cy3-labeled siRNA in A549 cells show that siRNAs are released from the PANs. Colocalization experiments with labeled endosomes and either labeled siRNAs prove the translocation of siRNAs into the cytosol. As a proof of concept, it is shown that PANs with encapsulated green fluorescence protein (GFP) siRNAs silence GFP in A549 cells expressing this protein. Silencing efficacy was evaluated by flow cytometry, CLSM, and Western blot assays. These results open the way for the use of poly(allylamine) phosphate nanocarriers for the intracellular delivery of genetic materials.

Cationic copolymer augments membrane permeabilizing activity of an amphiphilic peptide.

Membrane disruptive peptides (also called membrane fusogenic peptides) have been employed for cytosolic delivery of macromolecules such as nucleic acids and proteins. We reported previously that the cationic graft copolymer, poly(allylamine)-graft-dextran (PAA-g-Dex), augments membrane disruptive activity of the negatively charged E5 peptide. Strong membrane disruptive activity was observed in the presence of the copolymer at both acidic and neutral pH. In this paper, activities of E5/PAA-g-Dex mixture were further explored. Membrane permeabilization activity of E5/PAA-g-Dex was dependent on concentrations of both E5 and PAA-g-Dex, indicating that a complex between E5 and PAA-g-Dex produced the activity. Since the activity of peptide/PAA-g-Dex was peptide sequence-specific, we reasoned that PAA-g-Dex activated membrane-permeabilization activity by facilitating folding of E5 into its active conformation. The membrane permeabilization activity of E5/PAA-g-Dex resulted in transportation of bovine serum albumin into HL-60 cells with less cellular toxicity than digitonin, a naturally occurring surfactant used for delivery of macromolecules into cells.

Biodegradable mesoporous delivery system for biomineralization precursors.

Scaffold supplements such as nanoparticles, components of the extracellular matrix, or growth factors have been incorporated in conventional scaffold materials to produce smart scaffolds for tissue engineering of damaged hard tissues. Due to increasing concerns on the clinical side effects of using large doses of recombinant bone-morphogenetic protein-2 in bone surgery, it is desirable to develop an alternative nanoscale scaffold supplement that is not only osteoinductive, but is also multifunctional in that it can perform other significant bone regenerative roles apart from stimulation of osteogenic differentiation. Because both amorphous calcium phosphate (ACP) and silica are osteoinductive, a biodegradable, nonfunctionalized, expanded-pore mesoporous silica nanoparticle carrier was developed for loading, storage, and sustained release of a novel, biosilicification-inspired, polyamine-stabilized liquid precursor phase of ACP for collagen biomineralization and for release of orthosilicic acid, both of which are conducive to bone growth. Positively charged poly(allylamine)-stabilized ACP (PAH-ACP) could be effectively loaded and released from nonfunctionalized expanded-pore mesoporous silica nanoparticles (pMSN). The PAH-ACP released from loaded pMSN still retained its ability to infiltrate and mineralize collagen fibrils. Complete degradation of pMSN occurred following unloading of their PAH-ACP cargo. Because PAH-ACP loaded pMSN possesses relatively low cytotoxicity to human bone marrow-derived mesenchymal stem cells, these nanoparticles may be blended with any osteoconductive scaffold with macro- and microporosities as a versatile scaffold supplement to enhance bone regeneration.

The inhibitor of semicarbazide-sensitive amine oxidase, PXS-4728A, ameliorates key features of chronic obstructive pulmonary disease in a mouse model.

BACKGROUND AND PURPOSE: Chronic obstructive pulmonary disease (COPD) is a major cause of illness and death, often induced by cigarette smoking (CS). It is characterized by pulmonary inflammation and fibrosis that impairs lung function. Existing treatments aim to control symptoms but have low efficacy, and there are no broadly effective treatments. A new potential target is the ectoenzyme, semicarbazide-sensitive mono-amine oxidase (SSAO; also known as vascular adhesion protein-1). SSAO is elevated in smokers' serum and is a pro-inflammatory enzyme facilitating adhesion and transmigration of leukocytes from the vasculature to sites of inflammation. EXPERIMENTAL APPROACH: PXS-4728A was developed as a low MW inhibitor of SSAO. A model of COPD induced by CS in mice reproduces key aspects of human COPD, including chronic airway inflammation, fibrosis and impaired lung function. This model was used to assess suppression of SSAO activity and amelioration of inflammation and other characteristic features of COPD. KEY RESULTS: Treatment with PXS-4728A completely inhibited lung and systemic SSAO activity induced by acute and chronic CS-exposure. Daily oral treatment inhibited airway inflammation (immune cell influx and inflammatory factors) induced by acute CS-exposure. Therapeutic treatment during chronic CS-exposure, when the key features of experimental COPD develop and progress, substantially suppressed inflammatory cell influx and fibrosis in the airways and improved lung function. CONCLUSIONS AND IMPLICATIONS: Treatment with a low MW inhibitor of SSAO, PXS-4728A, suppressed airway inflammation and fibrosis and improved lung function in experimental COPD, demonstrating the therapeutic potential of PXS-4728A for this debilitating disease.

Preparation and characterization of magnetic allylamine modified graphene oxide-poly(vinyl acetate-co-divinylbenzene) nanocomposite for vortex assisted magnetic solid phase extraction of some metal ions.

Magnetic allylamine modified graphene oxide-poly(vinyl acetate-co-divinylbenzene) (MGO-DVB-VA) was synthesized and used for magnetic solid phase extraction of Pb(II), Cd(II), Cu(II), Ni(II) and Co(II) prior to their determination by flame atomic absorption spectroscopy. The adsorbent surface functional group was characterized by using FT-IR and Raman spectroscopy. XRD pattern was used to determine the layers of GO. Surface morphology and elemental composition of the adsorbent were evaluated by using SEM and EDX analysis. Various parameters, effecting adsorption efficiency like initial solution pH, adsorbent dose, type and volume of eluent, volume of sample and diverse ions effects were optimized. The preconcentration factor (PF) is 40 for all the metals and the limits of detection for Pb, Cd, Cu, Ni and Co are in the range of 0.37-2.39 µg L(-1) and relative standard deviation below 3.1%. The method was validated by using the method for certified reference materials (Tobacco Leaves (INCT-OBTL-5), Tomato Leaves (1573a), Certified Water (SPS-ww2) and Certified Water (TMDA 64-2)). The method was successfully applied for natural water and food samples.

Interstitial renal fibrosis due to multiple cisplatin treatments is ameliorated by semicarbazide-sensitive amine oxidase inhibition.

Elucidation of acute kidney diseases and disorders (AKD), including acute kidney injury (AKI), is important to prevent their progression to chronic kidney disease. Current animal AKI models are often too severe for use in evaluating human AKI. Therefore, new animal models of mild kidney injury are needed. Here a new clinically relevant animal model using multiple low doses of cisplatin (CP) was used to evaluate AKD. When 10 mg/kg CP was administered intraperitoneally once weekly for three times to L-type fatty acid-binding protein (L-FABP) transgenic mice, moderate renal interstitial fibrosis and tubule dilatation occurred, accompanied by brush-border loss. Urinary L-FABP, a promising biomarker of AKI, changed more drastically than blood urea nitrogen or creatinine. Preventing fibrosis in organs was also studied. Oral administration of a recently reported selective semicarbazide-sensitive amine oxidase inhibitor, PXS-4728A, for 1 week attenuated kidney injury and interstitial fibrosis compared with vehicle. Inhibition of renal lipid accumulation in semicarbazide-sensitive amine oxidase inhibitor-treated mice, together with reduced oxidative stress and L-FABP suppression in proximal tubules, suggested an antifibrotic effect of semicarbazide-sensitive amine oxidase inhibition in this CP-AKD model, a representative onco-nephrology. Thus, semicarbazide-sensitive amine oxidase inhibitors may be promising candidates for the prevention of chronic kidney disease in patients using CP to treat malignancy.

In Vitro Efficacy of Naftifine Against Lymphoma and Multiple Myeloma.

BACKGROUND/AIM: Multiple myeloma is still an incurable hematological malignancy of monoclonal B-lymphocytes. While standard chemotherapy regimens have been used for years, novel agents like lenalidomide and bortezomib have become an essential part of today's therapies and significantly improve therapeutic efficacy. Nevertheless, new therapeutic strategies are still indispensable. Aberrant activation of Wnt/ß-catenin signaling promotes development of several cancers. Recently, it has been demonstrated that the Wnt pathway is activated in both lymphoma and myeloma. Thus, Wnt signaling molecules are attractive candidates for the development of new targeted-therapies. Naftifine was used in the present study since it has chemical features similar to those of other known WNT inhibitors. MATERIALS AND METHODS: The anti-tumor apoptotic effect of naftifine at doses ranging from 0.1-200 µM was investigated on two human and one murine lymphoma, as well as in one murine and three human myeloma cell lines, and determinded by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium-bromide (MTT) assay. RESULTS: Naftifine significantly reduced cell viability in all tested myeloma and lymphoma cell lines in a dose-dependent manner, while healthy cells were only slightly affected. CONCLUSION: Naftifine exhibits toxicity to hematological neoplasms in vitro.

Effects of an anti-inflammatory VAP-1/SSAO inhibitor, PXS-4728A, on pulmonary neutrophil migration.

BACKGROUND AND PURPOSE: The persistent influx of neutrophils into the lung and subsequent tissue damage are characteristics of COPD, cystic fibrosis and acute lung inflammation. VAP-1/SSAO is an endothelial bound adhesion molecule with amine oxidase activity that is reported to be involved in neutrophil egress from the microvasculature during inflammation. This study explored the role of VAP-1/SSAO in neutrophilic lung mediated diseases and examined the therapeutic potential of the selective inhibitor PXS-4728A. METHODS: Mice treated with PXS-4728A underwent intra-vital microscopy visualization of the cremaster muscle upon CXCL1/KC stimulation. LPS inflammation, Klebsiella pneumoniae infection, cecal ligation and puncture as well as rhinovirus exacerbated asthma models were also assessed using PXS-4728A. RESULTS: Selective VAP-1/SSAO inhibition by PXS-4728A diminished leukocyte rolling and adherence induced by CXCL1/KC. Inhibition of VAP-1/SSAO also dampened the migration of neutrophils to the lungs in response to LPS, Klebsiella pneumoniae lung infection and CLP induced sepsis; whilst still allowing for normal neutrophil defense function, resulting in increased survival. The functional effects of this inhibition were demonstrated in the RV exacerbated asthma model, with a reduction in cellular infiltrate correlating with a reduction in airways hyperractivity. CONCLUSIONS AND IMPLICATIONS: This study demonstrates that the endothelial cell ligand VAP-1/SSAO contributes to the migration of neutrophils during acute lung inflammation, pulmonary infection and airway hyperractivity. These results highlight the potential of inhibiting of VAP-1/SSAO enzymatic function, by PXS-4728A, as a novel therapeutic approach in lung diseases that are characterized by neutrophilic pattern of inflammation.

Osteoblasts with impaired spreading capacity benefit from the positive charges of plasma polymerised allylamine.

Bone diseases such as osteoporosis, osteoarthritis and rheumatoid arthritis, impinge on the performance of orthopaedic implants by impairing bone regeneration. For this reason, the development of effective surface modifications supporting the ingrowth of implants in morbid bone tissue is essential. Our study is designed to elucidate if cells with restricted cell-function limiting adhesion processes benefit from plasma polymer deposition on titanium. We used the actin filament disrupting agent cytochalasin D (CD) as an experimental model for cells with impaired actin cytoskeleton. Indeed, the cell's capacity to adhere and spread was drastically reduced due to shortened actin filaments and vinculin contacts that were smaller. The coating of titanium with a positively charged nanolayer of plasma polymerised allylamine (PPAAm) abrogated these disadvantages in cell adhesion and the CD-treated osteoblasts were able to spread significantly. Interestingly, PPAAm increased spreading by causing enhanced vinculin number and contact length, but without significantly reorganising actin filaments. PPAAm with the monomer allylamine was deposited in a microwave-excited low-pressure plasma-processing reactor. Cell physiology was monitored by flow cytometry and confocal laser scanning microscopy, and the length and number of actin filaments was quantified by mathematical image processing. We showed that biomaterial surface modification with PPAAm could be beneficial even for osteoblasts with impaired cytoskeleton components. These insights into in vitro conditions may be used for the evaluation of future strategies to design implants for morbid bone tissue.

Colesevelam for the treatment of bile acid malabsorption-associated diarrhea in patients with Crohn's disease: a randomized, double-blind, placebo-controlled study.

BACKGROUND AND AIMS: Bile acid malabsorption (BAM)-associated diarrhea is an important clinical issue in patients with Crohn's disease (CD). We analyzed the efficacy and safety of the bile acid sequestrant colesevelam for treatment of BAM-associated diarrhea in CD patients in a randomized, double-blind, placebo-controlled study. METHODS: The primary endpoint was the proportion of patients with >30% reduction of liquid stools/day from baseline to termination visit at week 4. Secondary endpoints were reduction of the number of liquid stools/day, improvement of stool consistency and quality of life. RESULTS: 26 patients were analyzed in the intention-to-treat (ITT) analysis. The primary endpoint was reached by 10 patients (69.7%) in the colesevelam group compared to 3 patients (27.3%) in the placebo group (risk difference RD=.394, 95%CI:[-0.012; 0.706]; P=.0566). In the per-protocol analysis (n=22), the risk difference was statistically significant (RD=.470, 95%CI:[0.018; 0.788], P(H0: RD=0)=0.0364; 95% CI:[1.3;54.7]). Regarding secondary endpoints, in the ITT population colesevelam-treated patients had a significant reduction of liquid stools/day at week 4 (median 5.0 to 2.0; P=0.01), while patients treated with placebo had no significant reduction (median 4.0 to 3.0; P=0.42). Significantly more patients in the colesevelam group had improvement of stool consistency of at least one level in the Bristol stool chart, as compared to the placebo group (P=0.003). CONCLUSIONS: We found significant differences in favor for colesevelam treatment compared to placebo treatment for CD patients with BAM regarding the reduction of the number of liquid stools/day and stool consistency. ClinicalTrials.gov number: NCT01203254.

Colesevelam and colestipol: novel medication resins in the gastrointestinal tract.

We report the morphologic description of the bile acid sequestrants (BAS) colesevelam and colestipol, as well as the largest series of cholestyramine. Histologically similar medication resins from 4 institutions were prospectively collected over 1 year (26 specimens, 15 patients). Comorbidities included hyperlipidemia (4/15), hypertension (4/15), inflammatory bowel disease (4/15), coronary artery disease (3/15), diarrhea (7/15), hypothyroidism (2/15), and ischemic bowel (1/15). Sites of involvement included the esophagus (1/26), stomach (1/26), small intestine (1/26), ileocecal valve (1/26), and colorectum (22/26). Associated histologic diagnoses included normal (8/26), chronic mucosal injury (11/26), acute inflammation (9/26), erosion/ulceration (6/26), and cytomegalovirus (2/26). The BAS resins were histologically indistinguishable from each other; they were all eosinophilic on hematoxylin and eosin (H&E) and lacked internal "fish-scales." To validate these observations, respective medications were submitted for histologic processing; the processed medications were identical to those in the patient specimens. Rare, irregular "fracture" lines presented diagnostic pitfalls by mimicking the true "fish-scales" of Kayexalate and sevelamer. Clues to the correct identification of BAS include recognition that the "fracture" lines were subtle, irregular, and restricted to large fragments or thick sections, likely representing a processing artifact. Moreover, Kayexalate is violet on H&E and black on acid fast bacillus, and sevelamer characteristically displays a 2-tone color on H&E and is magenta on acid fast bacillus. An association with inflammatory injury was seen (15/26). We believe that the BAS are innocent bystanders in complicated patients, although we cannot exclude their ability to cause mucosal injury in specific settings.