Biological Applications of Programmable Optoelectrofluidic Manipulation

2009 ◽  
Vol 1173 ◽  
Author(s):  
Je-Kyun Park
Keyword(s):  
Liquid Crystal Display ◽  
Particle Diameter ◽  
Discrimination Performance ◽  
Local Concentration ◽  
Display Device ◽  
Ac Electroosmosis ◽  
Friction Forces ◽  
Ac Electrokinetics ◽  
Virtual Electrodes

AbstractThis paper presents a new programmable particle manipulation using a lab-on-a-display platform, which is a kind of optoelectrofluidic platform applying a liquid crystal display (LCD) as a display device for generating virtual electrodes in optoelectronic tweezers. The reconfigurable virtual electrodes in the lab-on-a-display are more advantageous than other devices which apply the micro-patterned electrodes, because we can freely control the size and position of electrodes as well as the voltage conditions, which affect the particle movements such as concentration and separation of particles. Due to its simple structures, cheap manufacturing costs, and high performances, this new LCD-based optoelectrofluidic platform can be applied to the interactive manipulation of polystyrene microspheres and blood cells. In addition, a method to discriminate normal oocytes for in vitro fertilization is demonstrated by combining the gravity effect with the optically induced positive dielectrophoresis (DEP). The discrimination performance can be enhanced due to the reduction of friction forces acting on the oocytes which are relatively large and heavy cells being affected by the gravity field. With the same device, we also demonstrate the size-dependent microparticle separation as well as the local concentration and assembly of microparticles originated from the image-driven AC electrokinetics such as DEP and AC electroosmosis. The particle movements result from the frequency-dependent behavior according to the particle diameter. This novel technique can be applied to rapidly concentrate, separate and pattern micro-/nanoparticles and biomolecules in many biological and chemical applications.

The Effect of Phase Transition Temperature on Therapeutic Efficacy of Liposomal Bortezomib

2020 ◽  
Vol 20 (6) ◽  
pp. 700-708
Author(s):  
Mitra Korani ◽  
Sara Nikoofal-Sahlabadi ◽  
Amin R. Nikpoor ◽  
Solmaz Ghaffari ◽  
Hossein Attar ◽  
...  
Keyword(s):  
Side Effects ◽  
Cell Line ◽  
Therapeutic Efficacy ◽  
Drug Loading ◽  
Particle Diameter ◽  
In Vitro Cytotoxicity ◽  
Liposomal Formulations ◽  
Cytotoxicity Studies ◽  
Anti Tumor Activity

Aims: Here, three liposomal formulations of DPPC/DPPG/Chol/DSPE-mPEG2000 (F1), DPPC/DPPG/Chol (F2) and HSPC/DPPG/Chol/DSPE-mPEG2000 (F3) encapsulating BTZ were prepared and characterized in terms of their size, surface charge, drug loading, and release profile. Mannitol was used as a trapping agent to entrap the BTZ inside the liposomal core. The cytotoxicity and anti-tumor activity of formulations were investigated in vitro and in vivo in mice bearing tumor. Background: Bortezomib (BTZ) is an FDA approved proteasome inhibitor for the treatment of mantle cell lymphoma and multiple myeloma. The low solubility of BTZ has been responsible for the several side effects and low therapeutic efficacy of the drug. Encapsulating BTZ in a nano drug delivery system; helps overcome such issues. Among NDDSs, liposomes are promising diagnostic and therapeutic delivery vehicles in cancer treatment. Objective: Evaluating anti-tumor activity of bortezomib liposomal formulations. Methods: Data prompted us to design and develop three different liposomal formulations of BTZ based on Tm parameter, which determines liposomal stiffness. DPPC (Tm 41°C) and HSPC (Tm 55°C) lipids were chosen as variables associated with liposome rigidity. In vitro cytotoxicity assay was then carried out for the three designed liposomal formulations on C26 and B16F0, which are the colon and melanoma cancer mouse-cell lines, respectively. NIH 3T3 mouse embryonic fibroblast cell line was also used as a normal cell line. The therapeutic efficacy of these formulations was further assessed in mice tumor models. Result: MBTZ were successfully encapsulated into all the three liposomal formulations with a high entrapment efficacy of 60, 64, and 84% for F1, F2, and F3, respectively. The findings showed that liposomes mean particle diameter ranged from 103.4 to 146.8nm. In vitro cytotoxicity studies showed that liposomal-BTZ formulations had higher IC50 value in comparison to free BTZ. F2-liposomes with DPPC, having lower Tm of 41°C, showed much higher anti-tumor efficacy in mice models of C26 and B16F0 tumors compared to F3-HSPC liposomes with a Tm of 55°C. F2 formulation also enhanced mice survival compared with untreated groups, either in BALB/c or in C57BL/6 mice. Conclusion: Our findings indicated that F2-DPPC-liposomal formulations prepared with Tm close to body temperature seem to be effective in reducing the side effects and increasing the therapeutic efficacy of BTZ and merits further investigation.

Preparation and Evaluation of Chitosan Loaded Naproxen Nanoparticles by Emulsion Interfacial Reaction Method

2019 ◽  
Vol 9 (2) ◽  
pp. 89-96
Author(s):  
Abbaraju Krishna Sailaja ◽  
Juveria Banu
Keyword(s):  
Drug Release ◽  
Interfacial Reaction ◽  
Polymer Concentration ◽  
Chitosan Nanoparticles ◽  
Particle Diameter ◽  
Entrapment Efficiency ◽  
Reaction Method ◽  
Release Data ◽  
Mean Particle Diameter

Aim: The aim of this investigation was to develop and characterize naproxen loaded chitosan nanoparticles by emulsion interfacial reaction method. Methodology: For emulsion interfacial reaction method chitosan was used as a polymer. In this method, eight formulations were prepared by varying drug to polymer concentration. Discussion: Out of eight formulations prepared using emulsion interfacial reaction method EI8 formulation was found to be the best formulation. The drug content was observed as 94.4%, entrapment efficiency and loading capacity were found to be 87.5% and 75%, respectively. The mean particle diameter was measured as 324.6nm and the Zeta potential value was found to be -42.4mv. In vitro drug release data showed 97.2% of drug release rate sustained up to 12hrs. Conclusion: The results clearly reveal that EI8 formulation having the highest amount of drug was considered as the best formulation because of its small mean particle diameter, good entrapment efficiency, and stability.

scholarly journals Prednisolone Loaded Tamarind Gum Microspheres for Colonic Delivery

2021 ◽  
pp. 324-332
Author(s):  
Harish K. Kunjwani ◽  
Dinesh M. Sakarkar
Keyword(s):  
Drug Release ◽  
Controlled Drug Release ◽  
Local Concentration ◽  
Colonic Delivery ◽  
Simulated Environment ◽  
S 100 ◽  
Long Time ◽  
Sensitive Property ◽  
Microsphere Preparation

The aim of this work was to formulate a novel multiparticulate system having pH sensitive property and specific enzyme biodegradability for colon specific drug delivery of Prednisolone (PD). Natural polysaccharide, Tamarind gum is used for microsphere preparation and Eudratit S- 100 for coating to provide pH controlled drug release. The formulation aims at minimal degradation and optimum delivery of the drug with relatively higher local concentration, which may provide more effective therapy for inflammatory bowel disease including Crohn disease and ulcerative colitis. Tamarind gum microspheres were prepared by emulsion dehydration technique using polymer in ratio of 1:1 to 1: 9. These microspheres were coated with Eudragit S-100 by oil in oil solvent evaporation method using core: coat ration (5:1). Tamarind gum microspheres and Eudragit coated tamarind gum microspheres were evaluated for surface morphology, particle size and size distribution, percentage drug entrapment, surface accumulation studies, in vitro drug release in simulated gastrointestinal fluids. The effect of various formulation variables were studied the prepared microspheres were spherical in shape in the size range of 64 µm to 113 µm, the encapsulation efficiency was in range of 30-72% depending upon the concentration of gum. The drug release was about 14-20% in first four hours of study gradually rises in 5th hour and 85% drug release occurs in 10-12% hr thus showing desirable drug release in the colonic simulated environment. PD tamarind gum microspheres are thought to have the potential to maintain drug concentration within target ranges for a long time, decreasing the side effects caused by concentration fluctuation, ensuring the efficiency of treatment and improving patient compliance by reducing dosing frequency. The animal study done using acetic acid induced colitis model on rats also suggest the anti inflammatory activity of the formulation.

scholarly journals The Retroviral Capsid Domain Dictates Virion Size, Morphology, and Coassembly of Gag into Virus-Like Particles

2005 ◽  
Vol 79 (21) ◽  
pp. 13463-13472 ◽  
Author(s):  
Danso Ako-Adjei ◽  
Marc C. Johnson ◽  
Volker M. Vogt
Keyword(s):  
Nuclear Export ◽  
Leukemia Virus ◽  
Particle Diameter ◽  
Particle Morphology ◽  
Structural Protein ◽  
Wild Type ◽  
Virus Like Particles ◽  
Gag Proteins ◽  
Hiv 1

ABSTRACT The retroviral structural protein, Gag, is capable of independently assembling into virus-like particles (VLPs) in living cells and in vitro. Immature VLPs of human immunodeficiency virus type 1 (HIV-1) and of Rous sarcoma virus (RSV) are morphologically distinct when viewed by transmission electron microscopy (TEM). To better understand the nature of the Gag-Gag interactions leading to these distinctions, we constructed vectors encoding several RSV/HIV-1 chimeric Gag proteins for expression in either insect cells or vertebrate cells. We used TEM, confocal fluorescence microscopy, and a novel correlative scanning EM (SEM)-confocal microscopy technique to study the assembly properties of these proteins. Most chimeric proteins assembled into regular VLPs, with the capsid (CA) domain being the primary determinant of overall particle diameter and morphology. The presence of domains between matrix and CA also influenced particle morphology by increasing the spacing between the inner electron-dense ring and the VLP membrane. Fluorescently tagged versions of wild-type RSV, HIV-1, or murine leukemia virus Gag did not colocalize in cells. However, wild-type Gag proteins colocalized extensively with chimeric Gag proteins bearing the same CA domain, implying that Gag interactions are mediated by CA. A dramatic example of this phenomenon was provided by a nuclear export-deficient chimera of RSV Gag carrying the HIV-1 CA domain, which by itself localized to the nucleus but relocalized to the cytoplasm in the presence of wild type HIV-1 Gag. Wild-type and chimeric Gag proteins were capable of coassembly into a single VLP as viewed by correlative fluorescence SEM if, and only if, the CA domain was derived from the same virus. These results imply that the primary selectivity of Gag-Gag interactions is determined by the CA domain.

scholarly journals Synthesis, Characterization, and In Vitro Drug Delivery of Chitosan-Silica Hybrid Microspheres for Bone Tissue Engineering

2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
Niu Niu ◽  
Shu-Hua Teng ◽  
Hua-Jian Zhou ◽  
Hai-Sheng Qian
Keyword(s):  
Drug Release ◽  
Sol Gel ◽  
Particle Diameter ◽  
Spherical Shape ◽  
Average Particle ◽  
High Dispersity ◽  
Model Drug ◽  
Regular Spherical Shape

Chitosan-silica (CS-SiO2) hybrid microspheres were prepared through the combined process of sol-gel and emulsification-crosslinking. Their composition, morphology, in vitro bioactivity, and drug release behavior were investigated. The results showed that, when 20 wt% SiO2 was incorporated, the as-prepared CS-SiO2 hybrid microspheres exhibited a regular spherical shape, a high dispersity, and a uniform microstructure. Their average particle diameter was determined to be about 24.0 μm. The in situ deposited inorganic phase of the hybrid microspheres was identified as amorphous SiO2, and its actual content was determined by the TG analysis. As compared with the pure chitosan microspheres, the CS-SiO2 hybrid microspheres displayed a greatly improved in vitro bioactivity. Vancomycin hydrochloride (VH) was selected as a model drug. It was demonstrated that the CS-SiO2 hybrid microspheres presented a good capacity for both loading and sustained release of VH. Moreover, the increase of the SiO2 content efficiently slowed down the drug release rate of the CS-SiO2 hybrid microspheres.

Computation of liquid crystal display device parameters through image analysis in supramolecule MA:nOBA

2020 ◽  
pp. 1-14
Author(s):  
Kalyani T ◽  
Mallika K ◽  
Ashok Kumar AVN ◽  
Sreehari Sastry Sreeramakavacham
Keyword(s):  
Image Analysis ◽  
Liquid Crystal ◽  
Liquid Crystal Display ◽  
Display Device

P-155: A Novel Liquid Crystal Display Device Applicable to Memory and Dynamic Modes with a Single Panel

2006 ◽  
Vol 37 (1) ◽  
pp. 794 ◽  
Author(s):  
Chul Gyu Jhun ◽  
Chao Ping Chen ◽  
Tae-Hoon Yoon ◽  
Jae Chang Kim
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystal Display ◽  
Display Device

Osseoinduction Evaluation of Hydroxyapatite and Zinc Containing Hydroxyapatite Granules in Rabbits

2011 ◽  
Vol 493-494 ◽  
pp. 252-257 ◽  
Author(s):  
L. Nascimento ◽  
M. Medeiros ◽  
J. Calasans-Maia ◽  
A. Alves ◽  
Antonella M. Rossi ◽  
...  
Keyword(s):  
Histological Analysis ◽  
Bone Matrix ◽  
Fibrous Tissue ◽  
Particle Diameter ◽  
Inflammatory Cells ◽  
Giant Cells ◽  
Multinucleated Giant Cells ◽  
Ethics Commission

This study investigated the osteoinductive potential of granules of stoichiometric hydroxyapatite (HA) and 0.5% zinc containing hydroxyapatite (ZnHA) in intramuscular (IM) site of rabbit’s abdomen. The biomaterials were both used in granular form, with 75% porosity and particle diameter between 450 and 500μm, sintered at 1100°C. Both materials performed adequately on a multiparametric in vitro cytocompatibility assay, indicating their suitability for in vivo testing. After approval by the Ethics Commission on Teaching and Research in Animals, fifteen rabbits were submitted to general anesthesia, incision and tissue dilatation, and a small site was created for HA (right incision) and ZnHA (left incision) intramuscular implantation. The animals were killed after 2, 4 and 12 weeks for biomaterials and surrounding tissues removal. Histological analysis after 2 weeks revealed the presence of granulation tissue surrounding biomaterials with multinucleated giant cells and no newly formed bone for both materials. After 4 weeks there was fibrous tissue involving the material and few inflammatory cells. Following 12 weeks it was observed the presence of connective tissue surrounding the biomaterial, cellularized enough for the two experimental groups, but it was not observed the presence of bone matrix associated with the biomaterials. We conclude that both biomaterials are cytocompatible and did not present the property of osseoinduction after 12 weeks of implantation.

Band-Separated UV Exposure on a Photosensitive Polyimide Layer With Embedded Reactive Mesogen for a High-Speed Liquid Crystal Display Device

2015 ◽  
Vol 62 (11) ◽  
pp. 3722-3726 ◽  
Author(s):  
Byung-June Mun ◽  
Joun Ho Lee ◽  
Byeong Koo Kim ◽  
Hyun Chul Choi ◽  
Bongsoon Kang ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
High Speed ◽  
Liquid Crystal Display ◽  
Uv Exposure ◽  
Display Device ◽  
Polyimide Layer
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