Co-existing Neuropeptide FF and Gonadotropin-Releasing Hormone 3 Coordinately Modulate Male Sexual Behavior.

Animals properly perform sexual behaviors by using multiple sensory cues. However, neural mechanisms integrating multiple sensory cues and regulating motivation for sexual behaviors remain unclear. Here, we focused on peptidergic neurons, terminal nerve gonadotropin-releasing hormone (TN-GnRH) neurons, which receive inputs from various sensory systems and co-express neuropeptide FF (NPFF) in addition to GnRH. Our behavioral analyses using knockout medaka of GnRH (gnrh3) and/or NPFF (npff) demonstrated that some sexual behavioral repertoires were delayed, not disrupted, in gnrh3 and npff single knockout males, while the double knockout appeared to alleviate the significant defects that were observed in single knockouts. We also found anatomical evidence to show that both neuropeptides modulate the sexual behavior-controlling brain areas. Furthermore, we demonstrated that NPFF activates neurons in the preoptic area via indirect pathway, which is considered to induce the increase in motivation for male sexual behaviors. Considering these results, we propose a novel mechanism by which co-existing peptides of the TN-GnRH neurons, NPFF, and GnRH3 coordinately modulate certain neuronal circuit for the control of behavioral motivation. Our results may go a long way toward understanding the functional significance of peptidergic neuromodulation in response to sensory information from the external environments.

Antibacterial Activity of Epoxy Resins Mixed with Polyelectrolyte/Silver Nanoparticle Composite Filler.

In this study, antibacterial polyelectrolyte/silver nanoparticle (Ag NP) composite powder was mixed with epoxy resins as fillers to impart antibacterial activity. Either an anhydride-type or a polyamideamine-type curing agent was applied to a bisphenol A-type base compound to prepare the epoxy resins. Antibacterial assays of these resins against Escherichia coli were performed using the shake tube technique; suppression of antibacterial activity was found for the anhydride-type resin, although the polyamideamine-type resin did exhibit antibacterial activity. The anhydride-type resin is considered to have suppressed antibacterial activity because carboxylate ions derived from unreacted anhydride in aqueous medium can induce chemical adsorption of silver ions and/or charge repulsion of E. coli.

Adsorption of Silver Nanoparticles onto Different Surface Structures of Chitin/Chitosan and Correlations with Antimicrobial Activities.

Size-controlled spherical silver nanoparticles (Ag NPs) can be simply prepared by autoclaving mixtures of glass powder containing silver with glucose. Moreover, chitins with varying degrees of deacetylation (DDAc < 30%) and chitosan powders and sheets (DDAc > 75%) with varying surface structure properties have been evaluated as Ag NP carriers. Chitin/chitosan-Ag NP composites in powder or sheet form were prepared by mixing Ag NP suspensions with each of the chitin/chitosan-based material at pH 7.3, leading to homogenous dispersion and stable adsorption of Ag NPs onto chitin carriers with nanoscale fiber-like surface structures, and chitosan carriers with nanoscale porous surface structures. Although these chitins exhibited mild antiviral, bactericidal, and antifungal activities, chitin powders with flat/smooth film-like surface structures had limited antimicrobial activities and Ag NP adsorption. The antimicrobial activities of chitin/chitosan-Ag NP composites increased with increasing amounts of adsorbed Ag NPs, suggesting that the surface structures of chitin/chitosan carriers strongly influence adsorption of Ag NPs and antimicrobial activities. These observations indicate that chitin/chitosan-Ag NPs with nanoscale surface structures have potential as antimicrobial biomaterials and anti-infectious wound dressings.

Preparation of size-controlled silver nanoparticles and chitosan-based composites and their anti-microbial activities.

We previously reported a simple method for the preparation of size-controlled spherical silver nanoparticles (Ag NPs) generated by autoclaving a mixture of silver-containing glass powder and glucose. The particle size is regulated by the glucose concentration, with concentrations of 0.25, 1.0 and 4.0 wt% glucose providing small (3.48 ± 1.83 nm in diameter), medium (6.53 ± 1.78 nm) and large (12.9 ± 2.5 nm) particles, respectively. In this study, Ag NP/chitosan composites were synthesized by mixing each of these three Ag NP suspensions with a 75% deacetylated (DAc) chitosan suspension (pH 5.0) at room temperature. The Ag NPs were homogeneously dispersed and stably embedded in the chitosan matrices. The Ag NP/chitosan composites were obtained as yellow or brown flocs. It was estimated that approximately 60, 120 and 360 µg of the small, medium and large Ag NPs, respectively, were maximally embedded in 1 mg of chitosan. The bactericidal and anti-fungal activities of the Ag NP/chitosan composites increased as the amount of Ag NPs in the chitosan matrix increased. Furthermore, smaller Ag NPs (per weight) in the chitosan composites provided higher bactericidal and anti-fungal activities.

Antiviral activity of silver nanoparticle/chitosan composites against H1N1 influenza A virus.

Silver nanoparticle (Ag NP)/chitosan (Ch) composites with antiviral activity against H1N1 influenza A virus were prepared. The Ag NP/Ch composites were obtained as yellow or brown floc-like powders following reaction at room temperature in aqueous medium. Ag NPs (3.5, 6.5, and 12.9 nm average diameters) were embedded into the chitosan matrix without aggregation or size alternation. The antiviral activity of the Ag NP/Ch composites was evaluated by comparing the TCID50 ratio of viral suspensions treated with the composites to untreated suspensions. For all sizes of Ag NPs tested, antiviral activity against H1N1 influenza A virus increased as the concentration of Ag NPs increased; chitosan alone exhibited no antiviral activity. Size dependence of the Ag NPs on antiviral activity was also observed: antiviral activity was generally stronger with smaller Ag NPs in the composites. These results indicate that Ag NP/Ch composites interacting with viruses exhibit antiviral activity.

Effective expansion of human adipose-derived stromal cells and bone marrow-derived mesenchymal stem cells cultured on a fragmin/protamine nanoparticles-coated substratum with human platelet-rich plasma.

Fragmin/protamine nanoparticles (F/P NPs) can be stably coated onto plastic surfaces and used as a substratum for the absorption and controlled release of growth factors (GFs) secreted from human platelet-rich plasma (PRP). In this study, we investigated the capability of F/P NP-coated plates to act as a substratum for the proliferation of human adipose-derived stromal cells (ASCs) and bone marrow-derived mesenchymal stem cells (BMSCs) with GFs in PRP. Both cell types adhered well to the F/P NP-coated plates and grew optimally, with a doubling time of 30 and 32 h in low-concentration PRP (0.5%) medium supplemented with 5 ng/ml fibroblast growth factor-2 (FGF-2) on the F/P NP-coated plates. These cells maintained their multilineage potential for differentiation into adipocytes or osteoblasts. Furthermore, ASCs and BMSCs grew well in medium without PRP and FGF-2 on F/P NP-coated plates pretreated with PRP and FGF-2 in a concentration-dependent manner. Thus, F/P NP-coated plates are a useful substratum for the adherence and proliferation of ASCs and BMSCs in low-concentration PRP medium supplemented with FGF-2. No xenogeneic serum is required.

Three-dimensional expansion using plasma-medium gel with fragmin/protamine nanoparticles and fgf-2 to stimulate adipose-derived stromal cells and bone marrow-derived mesenchymal stem cells.

Fragmin/protamine nanoparticles (F/P NPs) have been used as carriers for the preservation and controlled release of fibroblast growth factor (FGF)-2 and various cytokines in human plasma (HP). This study tested an HP-Dulbecco's modified Eagle's medium (DMEM) gel as a three-dimensional (3D) culture for the expansion of adipose tissue-derived multilineage stromal cells (ASCs) and bone marrow-derived mesenchymal stem cells (BMSCs). The growth of these cells improved in 3D culture using low-concentration HP (2%)-DMEM gel with 0.1 mg/mL F/P NPs and 5 ng/mL FGF-2 without animal serum in comparison to two-dimensional (2D) culture using a low-concentration human serum (2%)-DMEM containing 5 ng/mL FGF-2 on F/P NPs-coated plates. ASCs and BMSCs, which were expanded in the low-concentration HP-DMEM gel with F/P NPs and FGF-2, maintained their multilineage potential for differentiation into adipocytes or osteoblasts similar to the 2D cultured cells. Furthermore, flow cytometric analyses showed that the phenotypic markers which were positive for CD44, CD90, and CD105 (>80%) and negative for CD34 and CD45 (<1%) were well maintained in both 2D and 3D cultures after 7 days. Thus, this 3D culture system in low-concentration HP-DMEM gel with F/P NPs and FGF-2 provided an effective and safe method for the expansion of both cell types without using animal serum.

Novel experimental and clinical therapeutic uses of low-molecular-weight heparin/protamine microparticles.

Low-molecular-weight heparin/protamine microparticles (LMW-H/P MPs) were produced as a carrier for heparin-binding growth factors (GFs) and for various adhesive cells. A mixture of low-molecular-weight heparin (MW: approximately 5000 Da, 6.4 mg/mL) and protamine (MW: approximately 3000 Da, 10 mg/mL) at a ratio of 7:3 (vol:vol) yields a dispersion of microparticles (0.5-3 µm in diameter). LMW-H/P MPs immobilize, control the release and protect the activity of GFs. LMW-H/P MPs can also bind to cell surfaces, causing these cells to interact with the LMW-H/P MPs, inducing cells/MPs-aggregate formation and substantially promoting cellular viability. Furthermore, LMW-H/P MPs can efficiently bind to tissue culture plates and retain the binding of important GFs, such as fibroblast growth factor (FGF)-2. The LMW-H/P MPs-coated matrix with various GFs or cytokines may provide novel biomaterials that can control cellular activity such as growth and differentiation. Thus, LMW-H/P MPs are an excellent carrier for GFs and various cells and are an efficient coating matrix for cell cultures.

Increased survival of free fat grafts and vascularization in rats with local delivery of fragmin/protamine microparticles containing FGF-2 (F/P MP-F).

We evaluated the effects of fragmin/protamine micro-particles (F/P MPs) containing FGF-2 (F/P MP-F) as carriers for the controlled release of FGF-2 for adipocyte-survival and capillary formation in inbred rats with subdivided free fat grafts. F/P MPs could immobilize FGF-2, thereafter gradually releasing the bound FGF-2. Inbred Fisher 344 rats weighing around 150 g were anesthetized and implanted with paste comprising harvested fat combined with F/P MP-F. The effect of F/P MP-F on the survival, granulation, and capillary formation in fat grafts was histologically compared with control grafts containing either FGF-2, F/P MPs or PBS. The control fat grafts became attached to tissues adjacent to the implantation site and were significantly resorbed after 30 days. In contrast, pink, soft, supple grafts were compressible and were little resorbed in the group given F/P FP MP-F at 30-120 days. Normal adipocytes were obviously decreased in the control groups with increased granulation tissues, whereas normal adipocytes with capillary formations were maintained in the F/P MP-F group. Thus, adding F/P MP-F to subdivided fat grafts helps to improve graft volume retention and survival in soft-tissue reconstruction through accelerating adipocyte-survival rates and angiogenesis.

Selective Expansion of CD34+ Cells from Mouse Bone Marrow Cultured on LH/P MP-Coated Plates with Adequate Cytokines.

Low-molecular-weight heparin/protamine microparticles (LH/P MPs) serve as carriers for controlled release of heparin-binding cytokines. LH/P MPs were stably coated onto plastic surfaces by drying. The purpose of this study is to evaluate a culture method for selective expansion of CD34+ cells using LH/P MPs as cytokine-binding matrix. Ficoll-purified mouse bone marrow cells (mouse FP-BMCs) containing CD34+ cells were cultured on LH/P MP-coated plates in the presence of stem cell factor (SCF), thrombopoietin (Tpo), and Flt-3 ligand (Flt-3) in hematopoietic progenitor growth medium (HPGM) supplemented with 4% heat-inactivated fetal bovine serum (FBS). After 8 days of culture, the total cell count increased 4.6-fold, and flow cytometry analyses revealed that 23.8% of the initial cells and 57.4% of the expanded cells were CD34 positive. Therefore, CD34+ cells were estimated to have increased 11.0-fold. In contrast, cultured CD34+ cells on uncoated tissue culture plates increased 5.8-fold in an identical medium.

Preparation and characterization of low-molecular-weight heparin/protamine nanoparticles (LMW-H/P NPs) as FGF-2 carrier.

We produced low-molecular-weight heparin/protamine nanoparticles (LMW-H/P NPs) as a carrier for heparin-binding growth factors, such as fibroblast growth factor-2 (FGF-2). A mixture of low-molecular-weight heparin (MW: about 5000 Da, 6.4 mg/mL) and protamine (MW: about 3000 Da, 10 mg/mL) at a ratio of 7:3 (vol:vol) yields a dispersion of microparticles (1-6 microm in diameter). In this study, diluted low-molecular-weight heparin solution in saline (0.32 mg/mL) mixed with diluted protamine (0.5 mg/mL) at a ratio at 7:3 (vol:vol) resulted in soluble nanoparticles (112.5 +/- 46.1 nm in diameter). The generated NPs could be then stabilized by adding 2 mg/mL dextran (MW: 178-217 kDa) and remained soluble after lyophilization of dialyzed LMW-H/P NP solution. We then evaluated the capacity of LMW-H/P NPs to protect activity of FGF-2. Interaction between FGF-2 and LMW-H/P NPs substantially prolonged the biological half-life of FGF-2. Furthermore, FGF-2 molecules were protected from inactivation by heat and proteolysis in the presence of LMW-H/P NPs.

Immobilization, stabilization, and activation of human stem cell factor (SCF) on fragmin/protamine microparticle (F/P MP)-coated plates.

Fragmin (low-molecular-weight heparin)/protamine microparticles (F/P MPs) immobilize to culture plates, thereby retaining the binding of heparin-binding cytokines such as human stem cell factor (SCF). The purpose of this study was to evaluate the ability of F/P MP-coating to immobilize, stabilize, and enhance SCF-activity. Cell assays showed that SCF and preimmobilized SCF on F/P MP-coated plates significantly stimulated the proliferation of human erythroleukemia cell line TF-1 in a concentration-dependent manner. Heparin and fragmin enhanced SCF-induced proliferation of chlorate-treated TF-1 cells, in which the biosynthesis of endogenous sulfated polysaccharides was blocked, on noncoated plates at a range of concentrations (2-8 microg/mL). However, heparin and fragmin had no effect on SCF-induced proliferation of chlorate-treated TF-1 cells on F/P MP-coated plates. The interaction of SCF with fragmin and F/P MPs prolonged the half-life of SCF bioactivity, and immobilized and protected SCF from inactivation, such as from heat and proteolysis. These results suggest that F/P MP-coated plates protect SCF and enhance its activity, and F/P MP-coating provides an excellent biomaterial to immobilize and retain heparin-binding cytokines, including SCF, in bioactive form for optimal expansion of hematopoietic cells.

Fragmin/protamine microparticles as cell carriers to enhance viability of adipose-derived stromal cells and their subsequent effect on in vivo neovascularization.

We prepared fragmin/protamine microparticles (F/P MPs) as cell carriers to enhance cell viability. Use of material consisting of a low-molecular-weight heparin (fragmin) mixed with protamine resulted in water-insoluble microparticles (about 0.5-1 microm in diameter). In this study, we investigated the capability of F/P MPs to enhance the viabilities of human microvascular endothelial cells (HMVECs), human dermal fibroblasts (fibroblasts), and adipose tissue-derived stromal cells (ATSCs) in suspension culture. F/P MPs were bound to the surfaces of these cells, and the interaction of these cells with F/P MPs induced cells/F/P MPs-aggregate formations in vitro, and maintained viabilities of those cells for at least 3 days. The ATSCs/F/P MPs-aggregates adhered to and grew on suspension culture plates in a fashion similar to those on type I collagen-coated plates. The cultured ATSCs secreted significant amounts of angiogenic heparin-binding growth factors such as FGF-2. When the ATSCs/F/P MPs-aggregates were subcutaneously injected into the back of nude mice, significant neovascularization and fibrous tissue formation were induced near the site of injection from day 3 to week 2. The ATSCs/F/P MPs-aggregates were thus useful and convenient biomaterials for cell-therapy of angiogenesis.

Fragmin/protamine microparticle-coated matrix immobilized cytokines to stimulate various cell proliferations with low serum media.

Fragmin/protamine microparticles (F/P MPs) have been shown to bind to culture plates, thereby retaining heparin-binding cytokines. Most protocols for in vitro cultures of human microvascular endothelial cells (hMVECs), human dermal fibroblast cells (hDFCs), and hematopoietic cell line (TF-1) include high fetal bovine serum (FBS) (10%) medium as a nutritional supplement. Growth rates of those cells on the F/P MP-coated plates were higher in low FBS (1%) medium containing fibroblast growth factor (FGF)-2 (for hMVECs and hDFCs) and interleukin (IL)-3/granulocyte-macrophage colony-stimulating factor (for TF-1 cells) than without coating. The cytokines in low FBS medium were shown to be immobilized on the F/P MP-coated plate and released into the culture medium with a half releasing time of 4-5 days. Furthermore, those cells grew well on each cytokine-preimmobilized F/P MP-coated plate in low FBS medium. Thus, the F/P MP-coated matrix with adequate heparin-binding cytokines may provide biomaterials for controlling cellular growth and differentiation.

Expansion and characterization of human bone marrow-derived mesenchymal stem cells cultured on fragmin/protamine microparticle-coated matrix with fibroblast growth factor-2 in low serum medium.

Fragmin/protamine microparticles (F/P MPs) can be stably coated onto plastic surfaces. A capability of F/P MP-coated plates was investigated to immobilize fibroblast growth factor (FGF)-2 as a substratum to expand human bone marrow-derived mesenchymal stem cells (BMMSCs). FGF-2 molecules in low (2%) human serum (HS) medium were immobilized onto F/P MP-coated plates, and the FGF-2 was gradually released into the medium with a half-releasing time of 4-5 days. BMMSCs adhered well to the F/P MP-coated plates, and grew at a doubling time of about 28 h in low (2%) HS medium with FGF-2 (5 ng/mL), while the cells grew at a doubling time of about 30 and 38 h in high (10%) HS medium and in low (2%) HS medium with FGF-2, respectively, without F/P MP coating. The expanded BMMSCs on the F/P MP-coated plates in low (2%) HS medium with FGF-2 maintained their multilineage potential for differentiation into adipocytes and osteoblasts.

Synthesis of a sialic acid containing complex-type N-glycan on a solid support.

A new solid-phase synthesis of N-linked glycans featuring 1) highly stereoselective beta-mannosylation and microfluidic alpha-sialylation and 2) efficient glycosylation of the N-phenyltrifluoroacetimidate units on JandaJel resin is reported. Reagent concentration effects by a fluorous solvent are effectively applied, and the use of these methods results in the first synthesis of a sialic acid containing complex-type N-glycan on a solid support.

Human stem cell factor (SCF) is a heparin-binding cytokine.

Binding affinities of chemically modified heparins for human stem cell factor (SCF) were examined using fragmin/protamine microparticles (F/P MPs) and an enzyme-linked immunosorbent assay (ELISA). The binding of SCF to F/P MP-coated plates was inhibited with high concentrations of heparin and fragmin, but not others. The binding of SCF was also inhibited with 0.55 M or higher concentrations of NaCl in the medium. These results suggested that a high content of all three sulfate groups in repeating disaccharide units is required for interaction with SCF. Furthermore, pre-immobilized SCF on F/P MP-coated plates significantly stimulated proliferation of a human erythroleukemia cell line.

Single-particle light scattering study of polyethyleneglycol-grafted poly(ureaurethane) microcapsule in ethanol.

Microcapsules having polyethyleneglycol-grafted poly(ureaurethane) (PUU) membrane and di-2ethylhexyl phthalate core have been prepared, and the structure when they were suspended in dispersing ethanol have been studied by means of single-particle light scattering method. The PUU membrane was synthesized from monomers with aromatic functional groups (microcapsule MC110) and hexamethylene functional groups (microcapsule MC160). Because the outer and inner solvent passed through the membrane easily, the outside and inside of the membrane were the same at the equilibrium state. The thickness of the wall membrane was significantly smaller than that calculated from the overall weight ratio of the wall-forming material and the core solvents. It was attributed to low affinity of PUU membranes and ethanol.

Reagent-free crosslinking of aqueous gelatin: manufacture and characteristics of gelatin gels irradiated with gamma-ray and electron beam.

In order to obtain a gelatin hydrogel crosslinked by a reagent-free method, gamma-ray and electron beam radiation was applied to porcine, bovine and fish gelatin gels and the products were characterized by measuring the gel fraction, the swelling ratio and the enzymatic degradability. On increasing the radiation dose, the gel fraction increased and both the swelling ratio and the enzymatic degradability decreased. The transition temperature from gel to sol of the hydrogel containing more than 5% mammal gelatins increased up to more than 90 degrees C when gamma-ray or electron beam were irradiated by more than 10 kGy. The results show that the degree of crosslinking of irradiated gelatin hydrogels increases with increasing irradiation dose and with decreasing concentration. It is suggested that the radiation crosslinking occurs around the physical crosslinking point or multiple helix structure of gelatin gel.