scholarly journals Chitosan Oleate Salt as an Amphiphilic Polymer for the Surface Modification of Poly-Lactic-Glycolic Acid (PLGA) Nanoparticles. Preliminary Studies of Mucoadhesion and Cell Interaction Properties

Marine Drugs ◽  
2018 ◽  
Vol 16 (11) ◽  
pp. 447 ◽  
Author(s):  
Dalila Miele ◽  
Silvia Rossi ◽  
Giuseppina Sandri ◽  
Barbara Vigani ◽  
Milena Sorrenti ◽  
...  
Keyword(s):  
Glycolic Acid ◽  
Membrane Surface ◽  
Nile Red ◽  
Surface Characteristics ◽  
Cell Interaction ◽  
Plga Nanoparticles ◽  
Expected Improvement ◽  
Surface Modified ◽  
Surface Modified Nanoparticles ◽  
First Time

Most of the methods of poly-lactic-glycolic acid (PLGA) preparation involve the passage through the emulsification of a PLGA organic solution in water followed by solvent evaporation or extraction. The choice of the droplet stabilizer during the emulsion step is critical for the dimensions and the surface characteristics of the nanoparticles (NPs). In the present work, a recently described ionic amphiphilic chitosan derivative, chitosan oleate salt (CS-OA), was proposed for the first time to prepare PLGA NPs. A full factorial design was used to understand the effect of some formulation and preparation parameters on the NP dimensions and on encapsulation efficiency (EE%) of Nile red, used as a tracer. On the basis of the DoE study, curcumin loaded NPs were prepared, having 329 ± 42 nm dimensions and 68.75% EE%. The presence of a chitosan coating at the surface was confirmed by positive zeta potential and resulted in mucoadhesion behavior. The expected improvement of the interaction of the chitosan surface modified nanoparticles with cell membrane surface was confirmed in Caco-2 cell culture by the internalization of the loaded curcumin.

Morphology-Controlled 2D Ordered Microstructure Arrays by Surface Modification of Colloidal Template

2008 ◽  
Vol 8 (9) ◽  
pp. 4436-4440 ◽  
Author(s):  
Jian-Hong Lee ◽  
Ing-Chi Leu ◽  
Yi-Wen Chung ◽  
Min-Hsiung Hon
Keyword(s):  
Surface Characteristics ◽  
Two Dimensional ◽  
Polystyrene Spheres ◽  
Self Assembled Monolayer ◽  
Periodic Arrays ◽  
Colloidal Monolayer ◽  
Surface Modified ◽  
Modified Polystyrene ◽  
First Time ◽  
Structure Patterns

In this paper, we describe a convenient approach for fabricating two-dimensional, ordered TiO2 bowl-like structure and inverted-bowl-like structure patterns consisting of submicrometer arrays on a self-assembled monolayer film, for the first time using a surface-modified polystyrene colloidal monolayer as the template. Typically, the well-ordered two-dimensional TiO2 bowl-like structures were obtained by liquid phase deposition within the interstitial voids in assemblies of polystyrene spheres followed by the dissolution of the polystyrene template with dichloromethane. Otherwise, through a simple wet treatment by immersing in the sulfuric acid at 50 °C, the surface characteristics of polystyrene were turned from hydrophobic to hydrophilic. The ordered inverted-bowl-like structures could be prepared on this treated surface. We believe that this method could be extendable to colloidal template with smaller dimensions, and to periodic arrays made of other materials.

scholarly journals Clarithromycin-Loaded Poly (Lactic-co-glycolic Acid) (PLGA) Nanoparticles for Oral Administration: Effect of Polymer Molecular Weight and Surface Modification with Chitosan on Formulation, Nanoparticle Characterization and Antibacterial Effects

Polymers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1632 ◽  
Author(s):  
A. Alper Öztürk ◽  
Evrim Yenilmez ◽  
Mustafa Güçlü Özarda
Keyword(s):  
Oral Delivery ◽  
Glycolic Acid ◽  
In Vitro Release ◽  
Entrapment Efficiency ◽  
Plga Nanoparticles ◽  
Test Method ◽  
Molecular Weights ◽  
Antibiotic Group ◽  
Surface Modified

Clarithromycin (CLR) is a member of the macrolide antibiotic group. CLR has low systemic oral bioavailability and is a drug of class II of the Biopharmaceutical Classification System. In many studies, using nanoparticles (NPs) as a drug delivery system has been shown to increase the effectiveness and bioavailability of active drug substances. This study describes the development and evaluation of poly (lactic-co-glycolic acid) (PLGA) NPs and chitosan (CS)-coated PLGA NPs for oral delivery of CLR. NPs were obtained by nanoprecipitation technique and characterized in detail, and the effect of three molecular weights (Mw1: 7.000–17.000, Mw2: 38.000–54.000, Mw3: 50.000–190.000) of PLGA and CS coating on particle size (PS), zeta potential (ZP), entrapment efficiency (EE%), and release properties etc. were elucidated. Gastrointestinal stability and cryoprotectant effect tests were performed on the NPs. The PS of the prepared NPs were in the range of 178 to 578 nm and they were affected by the Mw and CS coating. In surface-modified formulations with CS, the ZP of the NPs increased significantly to positive values. EE% varied from 62% to 85%, depending upon the Mw and CS coating. In vitro release studies of CLR-loaded NPs showed an extended release up to 144 h. Peppas–Sahlin and Weibull kinetic model was found to fit best for CLR release from NPs. By the broth microdilution test method, the antibacterial activity of the formulations was determined on Staphylococcus aureus (ATCC 25923), Listeria monocytogenes (ATCC 1911), and Klebsiella pneumoniae (ATCC 700603). The structures of the formulations were clarified by thermal (DSC), FT-IR, and 1H-NMR analysis. The results showed that PS, ZP, EE%, and dissolution rates of NPs were directly related to the Mw of PLGA and CS coating.

scholarly journals IKBKB siRNA-Encapsulated Poly (Lactic-co-Glycolic Acid) Nanoparticles Diminish Neuropathic Pain by Inhibiting Microglial Activation

2021 ◽  
Vol 22 (11) ◽  
pp. 5657
Author(s):  
Seounghun Lee ◽  
Hyo-Jung Shin ◽  
Chan Noh ◽  
Song-I Kim ◽  
Young-Kwon Ko ◽  
...  
Keyword(s):  
Neuropathic Pain ◽  
Microglial Activation ◽  
Glycolic Acid ◽  
Nuclear Factor Kappa B ◽  
Decisive Role ◽  
Plga Nanoparticles ◽  
Spinal Nerve ◽  
Nuclear Factor ◽  
Interfering Rna

Activation of nuclear factor-kappa B (NF-κB) in microglia plays a decisive role in the progress of neuropathic pain, and the inhibitor of kappa B (IκB) is a protein that blocks the activation of NF-κB and is degraded by the inhibitor of NF-κB kinase subunit beta (IKBKB). The role of IKBKB is to break down IκB, which blocks the activity of NF-kB. Therefore, it prevents the activity of NK-kB. This study investigated whether neuropathic pain can be reduced in spinal nerve ligation (SNL) rats by reducing the activity of microglia by delivering IKBKB small interfering RNA (siRNA)-encapsulated poly (lactic-co-glycolic acid) (PLGA) nanoparticles. PLGA nanoparticles, as a carrier for the delivery of IKBKB genes silencer, were used because they have shown potential to enhance microglial targeting. SNL rats were injected with IKBKB siRNA-encapsulated PLGA nanoparticles intrathecally for behavioral tests on pain response. IKBKB siRNA was delivered for suppressing the expression of IKBKB. In rats injected with IKBKB siRNA-encapsulated PLGA nanoparticles, allodynia caused by mechanical stimulation was reduced, and the secretion of pro-inflammatory mediators due to NF-κB was reduced. Delivering IKBKB siRNA through PLGA nanoparticles can effectively control the inflammatory response and is worth studying as a treatment for neuropathic pain.

scholarly journals New Synthetic Methods of Novel Nanoporous Polycondensates and Excellent Oxygen Permselectivity of Their Composite Membranes

Nanomaterials ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 859
Author(s):  
Yu Zang ◽  
Toshiki Aoki ◽  
Masahiro Teraguchi ◽  
Takashi Kaneko ◽  
Hongge Jia ◽  
...  
Keyword(s):  
Contact Angle ◽  
Upper Bound ◽  
Oxygen Permeability ◽  
Membrane Surface ◽  
Composite Membranes ◽  
Synthetic Methods ◽  
Preparation Methods ◽  
First Time

Two kinds of novel nanoporous polycondensates (sc(Rf)) have been synthesized by two new preparation methods consisting of polycondensation and highly selective photocyclicaromataization of 1/3 helical cis-cis polyphenylacetylenes with polymerizable groups. By the original methods, new well-defined sheet polymers having nanopores or nanospaces have been synthesized for the first time. Their composite membranes, containing small amounts (1.0 wt%) of sc(Rf), had ultrahigh oxygen permeability (Po2 > 1000 barrer), and their plots were beyond the Robeson’s upper bound line in the graph of oxygen permselectivity (α = Po2/PN2) versus Po2. Both α and Po2 values were enhanced by adding only small amounts (1.0 wt%) of sc(Rf). One of the sc(Rf)s synthesized on the base membrane surface showed the best performance, i.e., Po2 = 5300 barrer and α = 2.5. The membrane surface was effectively covered by sc(Rf), judging from the contact angle values. It is thought that nanopores and nanospaces created in and between sc(Rf) molecules played an important role for the enhancement of both α and Po2/PN2.

Impact of Surface-Modified Nanoparticles on Glass Transition Temperature and Elastic Modulus of Polymer Thin Films

2007 ◽  
Vol 40 (22) ◽  
pp. 7755-7757 ◽  
Author(s):  
Jong-Young Lee ◽  
Kristin E. Su ◽  
Edwin P. Chan ◽  
Qingling Zhang ◽  
Todd Emrick ◽  
...  
Keyword(s):  
Thin Films ◽  
Glass Transition ◽  
Elastic Modulus ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Polymer Thin Films ◽  
Surface Modified ◽  
Surface Modified Nanoparticles

Possible Causes in Breaking of Dental Implants Research

2017 ◽  
Vol 907 ◽  
pp. 104-118
Author(s):  
Maria Stoicănescu ◽  
Eliza Buzamet ◽  
Dragos Vladimir Budei ◽  
Valentin Craciun ◽  
Roxana Budei ◽  
...  
Keyword(s):  
Dental Implants ◽  
Dental Implant ◽  
Scientific Literature ◽  
Surface Characteristics ◽  
Raw Material ◽  
New Materials ◽  
Materials Used ◽  
Type Of Failure ◽  
First Time ◽  
Consequent Increase

Dental implants are becoming increasingly used in current dental practice. This increased demand has motivated manufacturers to develop varieties of product through design, but also looking for new materials used to improve surface characteristics in order to obtain a better osseointegration. But the increase in the use of implants goes to a consequent increase in the number of failures. These failures are caused either by treatment complications (peri-implantitis), by fatigue breakage under mechanical over-stress, by defective raw material, or due to errors during the insertion procedures. Although they are rare, these complications are serious in dentistry. Before to market a dental implant to clinical practitioners, the product is validated among other determinations in number of biocompatibility research. Raw material issues, details about its structure and properties are less published by the scientific literature, but all this are subject of a carefully analysis of the producers. Breaking of dental implants during surgical procedures, during the prosthetic procedures or during use (chewing, bruxism, accidents, etc.), is the second most common cause of loss of an implant after consecutive peri-implantitis rejection. Although the frequency of this type of failure for a dental implant is much smaller than those caused by the peri-implantitis, a detailed study of broken implants can explain possible causes. The use of scanning electron microscopy (SEM) in the study of the cleave areas explain the production mechanism of cleavages, starting from micro-fissures in the alloy used for the production of dental implants. These micro-fissures in weak areas of the implant (anti-rotational corners of the polygons, etc.) could generate a serious risk of cleavage first time when a higher force is applied.

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