scholarly journals Multivalent Calixarene-Based Liposomes as Platforms for Gene and Drug Delivery

Pharmaceutics ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1250
Author(s):  
José Antonio Lebrón ◽  
Manuel López-López ◽  
Clara B. García-Calderón ◽  
Ivan V. Rosado ◽  
Fernando R. Balestra ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Side Effects ◽  
Encapsulation Efficiency ◽  
Transfection Efficiency ◽  
Genetic Material ◽  
The Other ◽  
Polar Group ◽  
Additional Amount ◽  
Upper Rim

The formation of calixarene-based liposomes was investigated, and the characterization of these nanostructures was carried out using several techniques. Four amphiphilic calixarenes were used. The length of the hydrophobic chains attached to the lower rim as well as the nature of the polar group present in the upper rim of the calixarenes were varied. The lipid bilayer was formed with one calixarene and with the phospholipid 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine, DOPE. The cytotoxicity of the liposomes for various cell lines was also studied. From the results obtained, the liposomes formed with the least cytotoxic calixarene, (TEAC12)4, were used as nanocarriers of both nucleic acids and the antineoplastic drug doxorubicin, DOX. Results showed that (TEAC12)4/DOPE/p-EGFP-C1 lipoplexes, of a given composition, can transfect the genetic material, although the transfection efficiency substantially increases in the presence of an additional amount of DOPE as coadjuvant. On the other hand, the (TEAC12)4/DOPE liposomes present a high doxorubicin encapsulation efficiency, and a slow controlled release, which could diminish the side effects of the drug.

Preparation and Characterization of Copolymeric Polymersomes for Protein Delivery

Drug Research ◽  
2017 ◽  
Vol 67 (08) ◽  
pp. 458-465 ◽  
Author(s):  
Alireza Nomani ◽  
Hamed Nosrati ◽  
Hamidreza Manjili ◽  
Leila Khesalpour ◽  
Hossein Danafar
Keyword(s):  
Drug Delivery ◽  
Protein Delivery ◽  
Encapsulation Efficiency ◽  
Controlled Drug Delivery ◽  
Protein Polymer ◽  
Biodegradable Copolymers ◽  
Model Protein ◽  
Sustained Protein Release ◽  
Polymer Ratio

AbstractBiodegradable copolymeric polymersomes have been used for controlled drug delivery of proteins. These polymersomes important areas to overcome formulation associated problems of the proteins. The aim of this study was to develop polymersomes using biodegradable copolymers for delivery of bovine serum albumin (BSA) as a model protein. Encapsulated BSA by mPEG-PCL polymersomes led to formation of BSA-loaded mPEG-PCL polymersomes. The polymersomes synthesized with the protein-polymer ratio of 1:4 at 15 000 rpm gave maximum loading, minimum polydispersion with maximally sustained protein release pattern, among the prepared polymersomes. Investigation on FTIR and DSC results revealed that such a high encapsulation efficiency is due to strong interaction between BSA and the copolymer.The particles size and their morphology of polymersomes were determined by DLS and AFM.The encapsulation efficiency of BSA was 91.02%. The results of AFM showed that the polymersomes had spherical shapes with size of 49 nm.The sizes of BSA-loaded polymersomes ranged from 66.06 nm to 84.97 nm. The results showed that polymersomes exhibited a triphasic release, for BSA. Overall, the results indicated that mPEG–PCL polymersomes can be considered as a promising carrier for proteins.

scholarly journals Lipid-Based Nanocarriers as Topical Drug Delivery Systems for Intraocular Diseases

Pharmaceutics ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 678
Author(s):  
Jose Navarro-Partida ◽  
Carlos Rodrigo Castro-Castaneda ◽  
Francisco J. Santa Cruz-Pavlovich ◽  
Luis Abraham Aceves-Franco ◽  
Tomer Ori Guy ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Clinical Practice ◽  
Side Effects ◽  
Half Life ◽  
Drug Delivery Systems ◽  
Genetic Material ◽  
Topical Drug Delivery ◽  
Important Target ◽  
Drug Concentrations ◽  
Intraocular Drug Delivery

Effective drug delivery to intraocular tissues remains a great challenge due to complex anatomical and physiological barriers that selectively limit the entry of drugs into the eye. To overcome these challenges, frequent topical application and regular intravitreal injections are currently used to achieve the desired drug concentrations into the eye. However, the repetitive installation or recurrent injections may result in several side effects. Recent advancements in the field of nanoparticle-based drug delivery have demonstrated promising results for topical ophthalmic nanotherapies in the treatment of intraocular diseases. Studies have revealed that nanocarriers enhance the intraocular half-life and bioavailability of several therapies including proteins, peptides and genetic material. Amongst the array of nanoparticles available nowadays, lipid-based nanosystems have shown an increased efficiency and feasibility in topical formulations, making them an important target for constant and thorough research in both preclinical and clinical practice. In this review, we will cover the promising lipid-based nanocarriers used in topical ophthalmic formulations for intraocular drug delivery.

scholarly journals Collection and Morphological Characterization of Local Okra (Abelmoschus esculentus L.) Genotypes in Northern Cyprus

2021 ◽  
Vol 9 (8) ◽  
pp. 1329-1332
Author(s):  
Nihat Yılmaz ◽  
Turgut Alas ◽  
Handan Ş Apcı Selamoğlu ◽  
Zeynep Arı ◽  
Hatice Bekci
Keyword(s):  
Genetic Material ◽  
Morphological Characterization ◽  
The Other ◽  
Abelmoschus Esculentus ◽  
Genetic Potential ◽  
Northern Cyprus ◽  
Characterization Studies ◽  
Second Year ◽  
Two Stages

This study was conducted to collect local Okra (Abelmoschus esculentus L.) genotypes belonging to Malvaceae (Mallow) family in the Northern Cyprus and morphological characterization of this collected material. On the other hand, due to the limited studies on collection and morphological characterization, which are the first step of breeding; the genetic potential of the local okra genotypes of Northern Cyprus has not been determined before. This research was carried out in two stages as the collection and morphological characterization of genotypes. In the first stage of the study, it was aimed to collect local okra genotypes and a total of 58 different locations were reached in line with this target and 24 samples of okra genotypes were collected from these areas. In the second year of the study, morphological characterization studies of 24 okra genotypes from the collected genetic material were carried out according to UPOV and IPGR criteria. As a result of morphological characterization showed that 24 okra genotypes can be categorized under 6 different groups. The regenerated seeds of these 6 different genotypes were preserved. In conclusion, although morphological characterization analyses performed in this study are the methods used to differentiate new species from each other, but it will be insufficient alone. Therefore, it is concluded that this method will be used in coordination with molecular characterization studies to provide more reliable results.

scholarly journals DESIGN AND CHARACTERIZATION OF CHLORZOXAZONE FLOATING BIOADHESIVE DRUG DELIVERY SYSTEM

2018 ◽  
Vol 11 (11) ◽  
pp. 222
Author(s):  
Manish Kumar Pal ◽  
Ganesh Deshmukh
Keyword(s):  
Drug Delivery ◽  
Drug Release ◽  
Drug Delivery System ◽  
Delivery System ◽  
The Other ◽  
Direct Compression ◽  
Total Dosage ◽  
Carbopol 934P

Objective: The objective of the work is to formulate chlorzoxazone floating bioadhesive tablets which will significantly improve the bioavailability of drugs under the condition of prolonged use of drugs and reduce the total dosage of administered drug and reduce the side effect.Methods: Floating bioadhesive tablet was prepared by direct compression of polymer such as HPMCK4M and Carbopol934p in combination.Result: After analysis of different evaluation parameter and drug release, F9 batch was selected as promising formulation for delivery of chlorzoxazone floating bioadhesive tablets with 92.1% drug release at 12th h.Conclusion: It was observed that the combination of polymers in 22.5% (HPMCK4M) and 12.5% (Carbopol 934p) give the best drug release and sustain the drug release for 12 h. Among the other batches, F9 batch was selected as an optimized batch because the pre- and post-compression parameters results are satisfactory.

scholarly journals Preparation and Characterization of a Novel Swellable and Floating Gastroretentive Drug Delivery System (sfGRDDS) for Enhanced Oral Bioavailability of Nilotinib

Pharmaceutics ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 137 ◽  
Author(s):  
Hong-Liang Lin ◽  
Ling-Chun Chen ◽  
Wen-Ting Cheng ◽  
Wei-Jie Cheng ◽  
Hsiu-O Ho ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Side Effects ◽  
Drug Delivery System ◽  
Delivery System ◽  
Oral Bioavailability ◽  
Optimal Dose ◽  
Pharmacokinetic Profile ◽  
Medical Need ◽  
Tablet Hardness

Regarding compliance and minimization of side effects of nilotinib therapy, there is a medical need to have a gastroretentive drug delivery system (GRDDS) to enhance the oral bioavailability that is able to administer an optimal dose in a quaque die (QD) or daily manner. In this study, the influence on a swelling and floating (sf) GRDDS composed of a polymeric excipient (HPMC 90SH 100K, HEC 250HHX, or PEO 7000K) and Kollidon® SR was examined. Results demonstrated that PEO 7000K/Kollidon SR (P/K) at a 7/3 ratio was determined to be a basic GRDDS formulation with optimal swelling and floating abilities. MCC PH102 or HPCsssl,SFP was further added at a 50% content to this basic formulation to increase the tablet hardness and release all of the drug within 24 h. Also, the caplet form and capsule form containing the same formulation demonstrated higher hardness for the former and enhanced floating ability for the latter. A pharmacokinetic study on rabbits with pH values in stomach and intestine similar to human confirmed that the enhanced oral bioavailability ranged from 2.65–8.39-fold with respect to Tasigna, a commercially available form of nilotinib. In conclusion, the multiple of enhancement of the oral bioavailability of nilotinib with sfGRDDS could offer a pharmacokinetic profile with therapeutic effectiveness for the QD administration of a reasonable dose of nilotinib, thereby increasing compliance and minimizing side effects.

Characterization of Laser Induced Backside Damage for Gettering Purposes

1981 ◽  
Vol 4 ◽  
Author(s):  
G.E.J. Eggermont ◽  
D.F. Allison ◽  
S.A. Gee ◽  
K.N. Ritz ◽  
R.J. Falster ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Surface Roughness ◽  
Side Effects ◽  
Laser Pulse ◽  
Laser Pulse Energy ◽  
Limited Range ◽  
The Other ◽  
Tem Analysis ◽  
Initial Oxidation

ABSTRACTA characterization of Q-switched Nd-YAG laser induced backside damage in various stages of a bipolar process is presented. TEM-analysis shows the occurence of microcracks, low angle boundaries and dislocations in as-irradiated wafers, of which the microcracks anneal out during an initial oxidation at 1050°C. The other damage is very stable and remains even after a heat treatment at 1200°C. This is quite in contrast with mechanically or Ar implantation induced backside damage, which anneal out completely at such high temperatures. Side effects of laser induced backside damage such as surface roughness and influence on wafer strength are found to be of no consequence within a limited range of laser pulse energy densities where the gettering efficiency is found to be very promising.

scholarly journals Characterization of progesterone loaded biodegradable blend polymeric nanoparticles

2015 ◽  
Vol 45 (11) ◽  
pp. 2082-2088 ◽  
Author(s):  
Fernanda Vitória Leimann ◽  
Maiara Heloisa Biz ◽  
Karine Cristine Kaufmann ◽  
Wallace José Maia ◽  
Odinei Hess Honçalves ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Encapsulation Efficiency ◽  
Polymeric Nanoparticles ◽  
Average Diameter ◽  
The Other ◽  
Narrow Size Distribution ◽  
Recovery Yield ◽  
Significant Difference ◽  
Evaporation Technique

ABSTRACT: The encapsulation of progesterone in poly (hydroxybutirate-co-hydroxyvalerate) (PHBV), poly (ε-caprolactone) (PCL), poly (L-lactic acid) (PLLA) nanoparticles and PHBV/PCL and PHBV/PLLA blend nanoparticles was investigated in this research. Nanoparticles were produced by miniemulsion/solvent evaporation technique with lecithin as surfactant and were characterized regarding to z-average diameter (Dz) and polydispersity (PDI), progesterone recovery yield and encapsulation efficiency. Possible interactions between progesterone and the polymer matrices were investigated by Fourier Transform Infrared Spectroscopy (FTIR). High recoveries (up to 102.43±1.80% for the PHBV/PLLA blend) and encapsulation efficiencies (up to 99.53±0.04% for PCL) were achieved and the nanoparticles presented narrow size distribution (0.12±0.03 for PLLA). PCL nanoparticles (217.5±2.12nm) presented significant difference with the Dz from all the other formulations (P<0.05). The most evident interaction between progesterone and the nanoparticles polymeric matrix was found to PHBV/PCL due to the increase in the intensity of the band located in 1631 cm-1.

A very rapid in situ Kikuchi technique to determine relative crystal misorientation

1988 ◽  
Vol 46 ◽  
pp. 830-831
Author(s):  
J. I. Bennetch
Keyword(s):  
Electron Beam ◽  
Analytical Techniques ◽  
Superplastic Forming ◽  
The Other ◽  
Kikuchi Pattern ◽  
Kikuchi Line ◽  
Line Analysis

In a recent study of the superplastic forming (SPF) behavior of certain Al-Li-X alloys, the relative misorientation between adjacent (sub)grains proved to be an important parameter. It is well established that the most accurate way to determine misorientation across boundaries is by Kikuchi line analysis. However, the SPF study required the characterization of a large number of (sub)grains in each sample to be statistically meaningful, a very time-consuming task even for comparatively rapid Kikuchi analytical techniques.In order to circumvent this problem, an alternate, even more rapid in-situ Kikuchi technique was devised, eliminating the need for the developing of negatives and any subsequent measurements on photographic plates. All that is required is a double tilt low backlash goniometer capable of tilting ± 45° in one axis and ± 30° in the other axis. The procedure is as follows. While viewing the microscope screen, one merely tilts the specimen until a standard recognizable reference Kikuchi pattern is centered, making sure, at the same time, that the focused electron beam remains on the (sub)grain in question.

Rapid Isolation of High Molecular Weight Urokinase from Native Human Urine

1982 ◽  
Vol 47 (03) ◽  
pp. 197-202 ◽  
Author(s):  
Kurt Huber ◽  
Johannes Kirchheimer ◽  
Bernd R Binder
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Human Urine ◽  
Gel Filtration ◽  
Chain Structure ◽  
The Other ◽  
Single Chain ◽  
Apparent Homogeneity ◽  
Sequential Adsorption

SummaryUrokinase (UK) could be purified to apparent homogeneity starting from crude urine by sequential adsorption and elution of the enzyme to gelatine-Sepharose and agmatine-Sepharose followed by gel filtration on Sephadex G-150. The purified product exhibited characteristics of the high molecular weight urokinase (HMW-UK) but did contain two distinct entities, one of which exhibited a two chain structure as reported for the HMW-UK while the other one exhibited an apparent single chain structure. The purification described is rapid and simple and results in an enzyme with probably no major alterations. Yields are high enough to obtain purified enzymes for characterization of UK from individual donors.

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