scholarly journals Coacervate Thermoresponsive Polysaccharide Nanoparticles as Delivery System for Piroxicam

2020 ◽  
Vol 21 (24) ◽  
pp. 9664
Author(s):  
Dorota Lachowicz ◽  
Agnieszka Kaczyńska ◽  
Anna Bodzon-Kulakowska ◽  
Anna Karewicz ◽  
Roma Wirecka ◽  
...  
Keyword(s):  
Delivery System ◽  
Water Solubility ◽  
Spherical Shape ◽  
Hydroxypropyl Cellulose ◽  
Biologically Active ◽  
Hydrodynamic Diameter ◽  
Temperature Dependent ◽  
Thermally Responsive ◽  
Derivatives Of ◽  
Average Hydrodynamic Diameter

Low water solubility frequently compromises the therapeutic efficacy of drugs and other biologically active molecules. Here, we report on coacervate polysaccharide nanoparticles (CPNs) that can transport and release a model hydrophobic drug, piroxicam, to the cells in response to changes in temperature. The proposed, temperature-responsive drug delivery system is based on ionic derivatives of natural polysaccharides—curdlan and hydroxypropyl cellulose. Curdlan was modified with trimethylammonium groups, while the anionic derivative of hydroxypropyl cellulose was obtained by the introduction of styrenesulfonate groups. Thermally responsive nanoparticles of spherical shape and average hydrodynamic diameter in the range of 250–300 nm were spontaneously formed in water from the obtained ionic polysaccharides as a result of the coacervation process. Their morphology was visualized using SEM and AFM. The size and the surface charge of the obtained objects could be tailored by adjusting the polycation/polyanion ratio. Piroxicam (PIX) was effectively entrapped inside the nanoparticles. The release profile of the drug from the CPNs-PIX was found to be temperature-dependent in the range relevant for biomedical applications.

Poly(N-Isopropylacrylamide) Microgel Synthesised by Emulsion Polymerization

2020 ◽  
Vol 307 ◽  
pp. 345-350
Author(s):  
Ernest Hsin Nam Yong ◽  
Kim Yeow Tshai ◽  
Siew Shee Lim ◽  
Ing Kong
Keyword(s):  
Main Chain ◽  
Hydrodynamic Diameter ◽  
Smart Polymers ◽  
Gravimetric Analysis ◽  
Thermal Gravimetric ◽  
Thermally Responsive ◽  
Hydrogel Particles ◽  
Chemical Behaviour ◽  
External Stimuli ◽  
Average Hydrodynamic Diameter

Smart polymers have been one of the most popularly studied materials owing to their capability to alter physio-chemical behaviour upon exposure to specific external stimuli. The biocompatible thermally responsive poly (N-isopropylacrylamide), PNIPAm shows reversible transition between hydrophilic-hydrophobic characteristics at the vicinity of human physiological temperature has great potential to propel the development of smart tissue engineering scaffold and drug delivery. However, the limited availability and its high cost have dampened the extent of research on this polymer. To address these challenges, the current work demonstrates an economical lab-scale polymerization of crosslinked PNIPAm and the optimised parameters to produce mono-dispersed polymer hydrogel particles were investigated. Characterisation of the synthesized PNIPAm polymer revealed particle size polydispersity index of 0.215, indicative of distribution within the mono-dispersed range, with average hydrodynamic diameter of 346.3 nm. Zeta-potential of the synthesized PNIPAm was found to be -20.6 mV, suggesting an incipient instability in terms of colloidal coagulation. Viscosity of the synthesized PNIPAm (4 wt% concentration in methanol) was 28.6 cP. Thermal gravimetric analysis (TGA) indicated the thermal degradation of main chain PNIPAm fell in the range of 340 to 480°C.

scholarly journals Biologically active derivatives of fullerene C60. Current state and development prospects

2020 ◽  
Vol 99 (3) ◽  
pp. 11-20
Author(s):  
S.D. Fazylov ◽  
◽  
О.А. Nurkenov ◽  
Z.M. Muldakhmetov ◽  
A.M. Gazaliev ◽  
...  
Keyword(s):  
Water Solubility ◽  
Biological Properties ◽  
Fullerene C60 ◽  
Biologically Active ◽  
Current State ◽  
Amino Derivatives ◽  
Relationship Of ◽  
The Relationship ◽  
Active Effects ◽  
Derivatives Of

The article presents literature review on the physicochemical and biological properties of fullerene C60, as well as the authors' own experimental data on the synthesis of fullerene derivatives of amines and natural alkaloids. It is shown that the presence of a fullerene fragment in the structure of the compound provides a significant improvement or the appearance of qualitatively new mechanical, chemical, physical, biological and other properties associated with the manifestation of nanoscale factors. The issues of the relationship of the structure, water solubility and biological activity of fullerene С60 derivatives are considered. Many biologically active effects of various modified derivatives of fullerene C60 are described, which have membrane-active, antibacterial, antiviral, immunomodulating, HIV inhibitory enzymes and other properties. It was noted that preparations containing a fullerene fragment are effective against hepatitis C virus, and are also able to efficiently trap free radicals. Derivatives of fullerenes can also be used as antioxidant, neuroprotective and other agents. Particular attention is paid to the authors' own results on the synthesis of amino derivatives of fullerenes.

scholarly journals Thermally-Responsive Loading and Release of Elastin-Like Polypeptides from Contact Lenses

Pharmaceutics ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 221 ◽  
Author(s):  
Wan Wang ◽  
Changrim Lee ◽  
Martha Pastuszka ◽  
Gordon W. Laurie ◽  
J. Andrew MacKay
Keyword(s):  
Contact Lenses ◽  
Anterior Segment ◽  
Biologically Active ◽  
Temperature Dependent ◽  
Thermally Responsive ◽  
Vision Correction ◽  
Biologically Active Peptide ◽  
Novel Strategy ◽  
First Time

Contact lenses are widely prescribed for vision correction, and as such they are an attractive platform for drug delivery to the anterior segment of the eye. This manuscript explores a novel strategy to drive the reversible adsorption of peptide-based therapeutics using commercially available contact lenses. To accomplish this, thermo-sensitive elastin-like polypeptides (ELPs) alone or tagged with a candidate ocular therapeutic were characterized. For the first time, this manuscript demonstrates that Proclear CompatiblesTM contact lenses are a suitable platform for ELP adsorption. Two rhodamine-labelled ELPs, V96 (thermo-sensitive) and S96 (thermo-insensitive), were employed to test temperature-dependent association to the contact lenses. During long-term release into solution, ELP coacervation significantly modulated the release profile whereby more than 80% of loaded V96 retained with a terminal half-life of ~4 months, which was only 1–4 days under solubilizing conditions. A selected ocular therapeutic candidate lacritin-V96 fusion (LV96), either free or lens-bound LV96, was successfully transferred to HCE-T cells. These data suggest that ELPs may be useful to control loading or release from certain formulations of contact lenses and present a potential for this platform to deliver a biologically active peptide to the ocular surface via contact lenses.

SOME DIRECTIONS IN THE MODIFICATION OF AZOLES

2020 ◽  
Vol 5 (443) ◽  
pp. 85-91
Author(s):  
Ibrayev M.K., ◽  
◽  
Takibayeva A.T., ◽  
Fazylov S.D., ◽  
Rakhimberlinova Zh.B., ◽  
...  
Keyword(s):  
13C Nmr Spectroscopy ◽  
Biologically Active Compounds ◽  
Biologically Active ◽  
Active Compounds ◽  
Synthesis Conditions ◽  
Alkaloid Cytisine ◽  
Azole Ring ◽  
Cyclic Compounds ◽  
New Compounds ◽  
Derivatives Of

This article presents studies on the targeted search for new derivatives of azoles, such as benzthiazole, 3,5-dimethylpyrazole, 1,3,4-oxadiazole-2-thione, 1,3,4-thiadiazole. The possibility of combining in one molecule of the azole ring with other cyclic compounds: the alkaloid cytisine, morpholine, furan and some arenes has been studied. To obtain new compounds, the reactions of bromination, acylation, and interaction with isothiocyanates were studied. Optimal synthesis conditions were studied for all reactions. It was found that the reaction of 4-bromo-3,5-dimethylpyrazole with isothiocyanates, in contrast to the previously written derivatives of anilines, takes a longer time and requires heating the reaction mixture. The combination of a pirasol fragment with halide substituents often results in an enhanced therapeutic effect. The synthesized 2-bromine-N-(6-rodanbenzo[d]thiazole-2-yl)acetamide, due to the alkylbromide group, is an important synth in the synthesis of new benzthiazole derivatives. Its derivatives combine in one molecule the rest of rhodanbenzthiazole with alkaloid cytisine and biogenic amine morpholine and are potentially biologically active compounds, since the molecule structure contains several pharmacophoric fragments: benzthiazole and alkaloid (amine) heterocycles, rhodane and urea groups. The mechanism of formation of 1,3,4-oxadiazole-2-tyons from hydrazides under action on them by carbon disulfide was studied and assumed. It was shown that dithiocarbamates in acidic medium decompose with the release of hydrogen sulfide and the formation of highly reactive isothiocyanate group. Then, intra-molecular cyclization occurs, with the formation of end products - 1,3,4-oxadiazole-2-thions. The structures of the synthesized compounds were studied by 1H and 13C NMR spectroscopy. All synthesized substances are potentially biologically active compounds, since they contain several pharmacophore fragments in their structure.

An Update on Recent Advances in Cubosome: A Novel Drug Delivery System

2021 ◽  
Vol 21 ◽  
Author(s):  
Madhukar Garg ◽  
Anju Goyal ◽  
Sapna Kumari
Keyword(s):  
Drug Delivery ◽  
Drug Delivery System ◽  
Lipid Bilayers ◽  
Delivery System ◽  
Liquid Crystalline ◽  
Three Dimensional ◽  
Biologically Active ◽  
Potential Applications ◽  
Health Related ◽  
Novel Drug

: Cubosomes are highly stable nanostructured liquid crystalline dosage delivery form derived from amphiphilic lipids and polymer-based stabilizers converting it in a form of effective biocompatible carrier for the drug delivery. The delivery form comprised of bicontinuous lipid bilayers arranged in three dimensional honeycombs like structure provided with two internal aqueous channels for incorporation of number of biologically active ingredients. In contrast liposomes they provide large surface area for incorporation of different types of ingredients. Due to the distinct advantages of biocompatibility and thermodynamic stability, cubosomes have remained the first preference as method of choice in the sustained release, controlled release and targeted release dosage forms as new drug delivery system for the better release of the drugs. As lot of advancement in the new form of dosage form has bring the novel avenues in drug delivery mechanisms so it was matter of worth to compile the latest updates on the various aspects of mentioned therapeutic delivery system including its structure, routes of applications along with the potential applications to encapsulate variety drugs to serve health related benefits.

scholarly journals Synthesis and Characterization of Chitosan-Based Nanodelivery Systems to Enhance the Anticancer Effect of Sorafenib Drug in Hepatocellular Carcinoma and Colorectal Adenocarcinoma Cells

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 497
Author(s):  
Umme Ruman ◽  
Kalaivani Buskaran ◽  
Giorgia Pastorin ◽  
Mas Jaffri Masarudin ◽  
Sharida Fakurazi ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Drug Delivery ◽  
Cell Lines ◽  
Delivery System ◽  
Colorectal Adenocarcinoma ◽  
Dermal Fibroblast ◽  
Spherical Shape ◽  
Ht29 Cell ◽  
Normal Human Dermal Fibroblast ◽  
Cancer Management

The formation of two nanodelivery systems, Sorafenib (SF)-loaded chitosan (SF-CS) and their folate-coated (SF-CS-FA) nanoparticles (NPs), were developed to enhance SF drug delivery on human Hepatocellular Carcinoma (HepG2) and Colorectal Adenocarcinoma (HT29) cell lines. The ionic gelation method was adopted to synthesize the NPs. The characterizations were performed by DLS, FESEM, TEM, XRD, TGA, FTIR, and UV-visible spectroscopy. It was found that 83.7 ± 2.4% and 87.9 ± 1.1% of encapsulation efficiency; 18.2 ± 1.3% and 19.9 ± 1.4% of loading content; 76.3 ± 13.7 nm and 81.6 ± 12.9 nm of hydrodynamic size; 60–80 nm and 70–100 nm of TEM; and FESEM sizes of near-spherical shape were observed, respectively, for SF-CS and SF-CS-FA nanoparticles. The SF showed excellent release from the nanoparticles under pH 4.8 PBS solution, indicating a good delivery system for tumor cells. The cytotoxicity study revealed their better anticancer action towards HepG2 and HT29 cell lines compared to the free sorafenib. Moreover, both NPs systems showed negligible toxicity to normal Human Dermal Fibroblast adult cells (HDFa). This is towards an enhanced anticancer drug delivery system with sustained-release properties for better cancer management.

scholarly journals Quantum-Chemical Search for Keto Tautomers of Azulenols in Vacuo and Aqueous Solution

Symmetry ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 497
Author(s):  
Ewa D. Raczyńska
Keyword(s):  
Aqueous Solution ◽  
Quantum Chemical ◽  
Biologically Active ◽  
Deprotonation Reaction ◽  
Chemical Studies ◽  
Quantum Chemical Studies ◽  
Scanty Information ◽  
Derivatives Of ◽  
Common Anion ◽  
Tautomeric Mixture

Keto-enol prototropic conversions for carbonyl compounds and phenols have been extensively studied, and many interesting review articles and even books appeared in the last 50 years. Quite a different situation takes place for derivatives of biologically active azulene, for which only scanty information on this phenomenon can be found in the literature. In this work, quantum-chemical studies have been undertaken for symmetrically and unsymmetrically substituted azulenols (constitutional isomers of naphthols). Stabilities of two enol (OH) rotamers and all possible keto (CH) tautomers have been analyzed in the gas phase {DFT(B3LYP)/6-311+G(d,p)} and also in aqueous solution {PCM(water)//DFT(B3LYP)/6-311+G(d,p)}. Contrary to naphthols, for which the keto forms can be neglected, at least one keto isomer (C1H, C2H, and/or C3H) contributes significantly to the tautomeric mixture of each azulenol to a higher degree in vacuo (non-polar environment) than in water (polar amphoteric solvent). The highest amounts of the CH forms have been found for 2- and 5-hydroxyazulenes, and the smallest ones for 1- and 6-hydroxy derivatives. The keto tautomer(s), together with the enol rotamers, can also participate in deprotonation reaction leading to a common anion and influence its acid-base properties. The strongest acidity in vacuo exhibits 6-hydroxyazulene, and the weakest one displays 1-hydroxyazulene, but all azulenols are stronger acids than phenol and naphthols. Bond length alternation in all DFT-optimized structures has been measured using the harmonic oscillator model of electron delocalization (HOMED) index. Generally, the HOMED values decrease for the keto tautomers, particularly for the ring containing the labile proton. Even for the keto tautomers possessing energetic parameters close to those of the enol isomers, the HOMED indices are low. However, some kind of parallelism exists for the keto forms between their relative energies and HOMEDs estimated for the entire molecules.

scholarly journals Silver Nanocolloids Loaded with Betulinic Acid with Enhanced Antitumor Potential: Physicochemical Characterization and In Vitro Evaluation

Nanomaterials ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 152
Author(s):  
Iulia Pinzaru ◽  
Cristian Sarau ◽  
Dorina Coricovac ◽  
Iasmina Marcovici ◽  
Crinela Utescu ◽  
...  
Keyword(s):  
Antitumor Activity ◽  
Betulinic Acid ◽  
Water Solubility ◽  
Physicochemical Characterization ◽  
A549 Cells ◽  
Drug Carriers ◽  
Biological Evaluation ◽  
Correlation Spectroscopy ◽  
Hydrodynamic Diameter

Betulinic acid (BA), a natural compound with various health benefits including selective antitumor activity, has a limited applicability in vivo due to its poor water solubility and bioavailability. Thus, this study focused on obtaining a BA nano-sized formulation with improved solubility and enhanced antitumor activity using silver nanocolloids (SilCo and PEG_SilCo) as drug carriers. The synthesis was performed using a chemical method and the physicochemical characterization was achieved applying UV-Vis absorption, transmission electron microscopy (TEM), Raman and photon correlation spectroscopy (PCS). The biological evaluation was conducted on two in vitro experimental models—hepatocellular carcinoma (HepG2) and lung cancer (A549) cell lines. The physicochemical characterization showed the following results: an average hydrodynamic diameter of 32 nm for SilCo_BA and 71 nm for PEG_SilCo_BA, a spherical shape, and a loading capacity of 54.1% for SilCo_BA and 61.9% for PEG_SilCo_BA, respectively. The in vitro assessment revealed a cell type- and time-dependent cytotoxic effect characterized by a decrease in cell viability as follows: (i) SilCo_BA (66.44%) < PEG_SilCo_BA (72.05%) < BA_DMSO (75.30%) in HepG2 cells, and (ii) SilCo_BA (75.28%) < PEG_SilCo_BA (86.80%) < BA_DMSO (87.99%) in A549 cells. The novel silver nanocolloids loaded with BA induced an augmented anticancer effect as compared to BA alone.

Synthesis of biologically active derivatives of cyclopenteno[d]-selenazole and their thioanalogs

1982 ◽  
Vol 16 (6) ◽  
pp. 460-463
Author(s):  
A. A. Tsurkan ◽  
Z. F. Gromova ◽  
�. A. Rudzit ◽  
G. N. Neshchadit ◽  
D. A. Kulikova
Keyword(s):  
Biologically Active ◽  
Derivatives Of ◽  
Biologically Active Derivatives
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