scholarly journals Synthesis and Characterization of New Biodegradable Injectable Thermosensitive Smart Hydrogels for 5-Fluorouracil Delivery

2021 ◽  
Vol 22 (15) ◽  
pp. 8330
Author(s):  
Adam Kasiński ◽  
Monika Zielińska-Pisklak ◽  
Sebastian Kowalczyk ◽  
Andrzej Plichta ◽  
Anna Zgadzaj ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Diffusion Mechanism ◽  
Sol Gel ◽  
Gel Permeation Chromatography ◽  
Local Drug Delivery ◽  
Release Time ◽  
Synthesis Conditions ◽  
First Order ◽  
Smart Hydrogel

In this paper, injectable, thermosensitive smart hydrogel local drug delivery systems (LDDSs) releasing the model antitumour drug 5-fluorouracil (5-FU) were developed. The systems were based on biodegradable triblock copolymers synthesized via ring opening polymerization (ROP) of ε-caprolactone (CL) in the presence of poly(ethylene glycol) (PEG) and zirconium(IV) acetylacetonate (Zr(acac)4), as co-initiator and catalyst, respectively. The structure, molecular weight (Mn) and molecular weight distribution (Đ) of the synthesized materials was studied in detail using nuclear magnetic resonance (NMR) and gel permeation chromatography (GPC) techniques; the optimal synthesis conditions were determined. The structure corresponded well to the theoretical assumptions. The produced hydrogels demonstrated a sharp sol–gel transition at temperature close to physiological value, forming a stable gel with good mechanical properties at 37 °C. The kinetics and mechanism of in vitro 5-FU release were characterized by zero order, first order, Higuchi and Korsmeyer–Peppas mathematical models. The obtained results indicate good release control; the kinetics were generally defined as first order according to the predominant diffusion mechanism; and the total drug release time was approximately 12 h. The copolymers were considered to be biodegradable and non-toxic; the resulting hydrogels appear to be promising as short-term LDDSs, potentially useful in antitumor therapy.

scholarly journals In Situ Gel Formation in Microporated Skin for Enhanced Topical Delivery of Niacinamide

Pharmaceutics ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 472 ◽  
Author(s):  
Sonalika Bhattaccharjee ◽  
Moritz Beck-Broichsitter ◽  
Ajay K. Banga
Keyword(s):  
Molecular Weight ◽  
Sol Gel ◽  
Topical Delivery ◽  
Needle Length ◽  
Molecular Weight Polymer ◽  
Sol Gel Transition ◽  
Pre Treatment ◽  
Franz Diffusion Cells

Although used widely in cosmetic formulations, topical delivery of niacinamide (LogP = −0.35) is unfavorable by conventional means. Poly(lactide-co-glycolide) (PLGA) formulations, can undergo a sol-gel transition triggered by solvent exchange, entrapping molecules and sustaining their release. The current study aims to exploit the ability of PLGA to gel in situ and enhance the topical delivery of niacinamide in microporated skin. In vitro drug permeation studies were performed using vertical Franz diffusion cells. Microporation was performed using Dr. PenTM Ultima A6, where pre-treatment with a 1 mm needle-length for 10 s and a 0.5 mm needle-length for 5 s, both at 13,000 insertions/min were compared. The effect of different grades of PLGA, EXPANSORB® DLG 50-2A (“low” molecular weight), and EXPANSORB® DLG 50-8A (“high” molecular weight) on topical delivery was also determined. Formulations containing PLGA resulted in successful gelation in situ on application over microporated skin. A significantly higher amount of drug was found in the skin with the 0.5 mm treatment for 5 s (892 ± 36 µg/cm2) than with 1 mm for 10 s (167 ± 16 µg/cm2). Hence, the different grades of PLGA were evaluated with 0.5 mm, 5 s treatment, and a significantly larger amount was seen in skin with the higher rather than the lower molecular weight polymer (172 ± 53 µg/cm2).

Measurement of soil-sebum partition coefficients for high molecular weight polycyclic aromatic hydrocarbons present at former gasworks, UK

2020 ◽  
Author(s):  
Darren J. Beriro ◽  
Mark R. Cave ◽  
Joanna Wragg ◽  
Russell Thomas ◽  
Christopher Taylor ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Polycyclic Aromatic Hydrocarbons ◽  
High Molecular Weight ◽  
Aromatic Hydrocarbons ◽  
Partition Coefficients ◽  
Release Time ◽  
Time Step ◽  
Polycyclic Aromatic ◽  
The Relationship

<p>The current research builds on the findings of a systematic literature review by the authors which recommends the need to work towards a standardised method for measuring the in vitro dermal absorption of HMW-PAH in soils. One part of the method is understanding the partitioning of the high molecular weight polycyclic aromatic hydrocarbons (HMW-PAH) from soil to sebum found in skin. In vitro HMW-PAH soil-sebum partition coefficients (KSS) were measured for twelve soils collected from former UK gasworks.  Concentrations of ∑16 USEPA PAH in the soils ranged from 51 to 1440 mg/kg, benzo[a]pyrene ranged from 3.2 to 132 mg/kg. Time series extractions (0.5, 1, 2, 4, 8 and 24 h) at skin temperature (32°C) of HMW-PAH from sebum to soil for two samples were conducted to determine the maximum release time-step. The maximum HMW-PAH release time-step was determined as 4 h, which was subsequently used as the extraction time for the remaining samples. Evaluation of KSS data for the 4 h extractions showed that soil type and selected HMW-PAH properties (literature based molecular weight and octanol-carbon partition coefficients) affect the amount of HMW-PAH released from soil into sebum. Characterisation of soil properties was limited to total organic carbon, which showed no relationship to KSS. Selected soils showed distinctly higher K¬SS than others. The relationship between MW and KSS was statistically significant while the relationship between KOC and KSS was not statistically significant. Further research effort is required to improve our understanding of which soil and HMW-PAH properties affect the release of HMW-PAH from soil into sebum and the reasons why.</p>

On the structure alteration of crosslinkable gelatin coupled with methacrylic acid and its hydrogel

e-Polymers ◽  
2012 ◽  
Vol 12 (1) ◽  
Author(s):  
Xiaohong Hu ◽  
Dan Li ◽  
Feng Zhou ◽  
Changyou Gao
Keyword(s):  
Molecular Weight ◽  
Triple Helix ◽  
Sol Gel ◽  
Average Molecular Weight ◽  
Gel Permeation Chromatography ◽  
Apparent Molecular Weight ◽  
Small Range ◽  
Scanning Calorimetry ◽  
Physical Chemical ◽  
Substitution Degree

AbstractPhysical structures of a crosslinkable gelatin derivative (GM) were studied in terms of alteration of apparent molecular weight, triple helix content and mechanical strength. The GM with a substitution degree (DS) of 49% and 79% was prepared by grafting mechacrylic acid (MA), which was able to form injectable hydrogel by photoinitiating polymerization. The zeta potential was increased along the increase of DS. After modification, the apparent number-average molecular weight (Mn) detected by gel permeation chromatography was decreased to about 2/3 of gelatin, while the apparent weight-average molecular weight (Mw) was changed within a small range. Differential scanning calorimetry and circular dichroism (CD) revealed that ability of triple-helix formation of GM was decreased along with the increase of DS and decrease of GM concentration. After photocrosslinking, the sol-gel transition of GM49 physical-chemical hydrogel still existed, but completely disappeared for its chemical hydrogel. The physical-chemical hydrogel showed a larger storage modulus at 20°C than at 37°C as a result of additional physical crosslinking.

scholarly journals Hydrogels Based on Poly(Ether-Ester)s as Highly Controlled 5-Fluorouracil Delivery Systems—Synthesis and Characterization

Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 98
Author(s):  
Adam Kasiński ◽  
Monika Zielińska-Pisklak ◽  
Ewa Oledzka ◽  
Grzegorz Nałęcz-Jawecki ◽  
Agata Drobniewska ◽  
...  
Keyword(s):  
Drug Release ◽  
Ethylene Glycol ◽  
Gel Permeation Chromatography ◽  
Zero Order ◽  
Hexamethylene Diisocyanate ◽  
Release Mechanism ◽  
Poly Ethylene Glycol ◽  
First Order ◽  
Poly Ethylene

A novel and promising hydrogel drug delivery system (DDS) capable of releasing 5‑fluorouracil (5-FU) in a prolonged and controlled manner was obtained using ε‑caprolactone‑poly(ethylene glycol) (CL-PEG) or rac‑lactide-poly(ethylene glycol) (rac‑LA-PEG) copolymers. Copolymers were synthesized via the ring-opening polymerization (ROP) process of cyclic monomers, ε‑caprolactone (CL) or rac-lactide (rac-LA), in the presence of zirconium(IV) octoate (Zr(Oct)4) and poly(ethylene glycol) 200 (PEG 200) as catalyst and initiator, respectively. Obtained triblock copolymers were characterized by nuclear magnetic resonance (NMR) and gel permeation chromatography (GPC) techniques; the structure and tacticity of the macromolecules were determined. The relationship between the copolymer structure and the reaction conditions was evaluated. The optimal conditions were specified as 140 °C and 24 h. In the next step, CL-PEG and rac-LA-PEG copolymers were chemically crosslinked using hexamethylene diisocyanate (HDI). Selected hydrogels were subjected to in vitro antitumor drug release studies, and the release data were analyzed using zero-order, first-order, and Korsmeyer-Peppas mathematical models. Controlled and prolonged (up to 432 h) 5-FU release profiles were observed for all examined hydrogels with first-order or zero-order kinetics. The drug release mechanism was generally denoted as non-Fickian transport.

scholarly journals Three-Dimensionally Ordered Macroporous-Mesoporous Bioactive Glass Ceramics for Drug Delivery Capacity and Evaluation of Drug Release

2020 ◽  
Author(s):  
Reedwan Bin Zafar Auniq ◽  
Namon Hirun ◽  
Upsorn Boonyang
Keyword(s):  
Drug Release ◽  
Bioactive Glass ◽  
Drug Loading ◽  
Diffusion Mechanism ◽  
Sol Gel ◽  
Glass Ceramics ◽  
Fickian Diffusion ◽  
Ordered Macroporous ◽  
Mesoporous Bioactive Glass

Bioactive glass ceramics (BGCs) have been used in orthopedic and dentistry due to having better osteoconductive and osteostimulative properties. This study aimed to evaluate and compare the drug release properties of two different BGCs; 45S5 and S53P4. The BGCs were composed with four phases of SiO2 – CaO – Na2O – P2O5 system, synthesized by sol–gel method using dual templates; a block-copolymer as mesoporous templates and polymer colloidal crystals as macroporous templates, called three-dimensionally ordered macroporous-mesoporous bioactive glass ceramics (3DOM-MBGCs). In vitro bioactivity test performed by soaking the 3DOM-MBGCs in simulated body fluid (SBF) at 37°C. The results indicated that, the 45S5 have the ability to grow hydroxyapatite-like layer on the surfaces faster than S53P4. Gentamicin drug was used to examine in vitro drug release properties in phosphate buffer solution (PBS). The amount of drug release was quantified through UV/Vis spectroscopy by using o-phthaldialdehyde reagent. S53P4 showed high drug loading content. The outcome of drug release in PBS showed that both S53P4 and 45S5 exhibited a slowly continuous gentamicin release. The resultant drug release profiles were fitted to the Peppas-Korsmeyer model to establish the predominant drug release mechanisms, which revealed that the kinetics of drug release from the glasses mostly dominated by Fickian diffusion mechanism.

Evaluation of Acid-Treated Hyaluronic Acid-Based Hydrogelation

2007 ◽  
Vol 342-343 ◽  
pp. 745-748
Author(s):  
Mi Sook Kim ◽  
Yoon Jeong Choi ◽  
Gun Woo Kim ◽  
In Sup Noh ◽  
Yong Doo Park ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Hyaluronic Acid ◽  
Gel Permeation Chromatography ◽  
Biological Properties ◽  
Cellular Interactions ◽  
Molecular Weights ◽  
Chemical Structures ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene

Though hyaluronic acid (HA)-based hydrogel has drawn great attention in biomedical society, it’s long molecular weights sometimes have been problematic due to its difficulty in handling. After reduction of its high molecular weight into smaller sizes with various concentrations of hydrogen chloride solutions, its chemical and biological properties have been examined by changes in viscosity, FTIR spectroscopy and gel permeation chromatography as well as cellular interactions. While FTIR analysis indicated maintenance of its original chemical structures, its viscosity has been remarkably reduced and its extent was dependent upon the employment of acid concentrations. After controlling its molecular weight to approximately 100 kDa and coupling of aminopropymethacrylate to the treated HA, we evaluated in vitro cellular interactions and cell proliferations of the HA-poly(ethylene oxide) (PEO) hydrogel.

Synthesis, Characterization, and Properties of Copolyanhydrides Based on 2-Octylsuccinic Acid and Sebacic Acid

2008 ◽  
Vol 61 (10) ◽  
pp. 762 ◽  
Author(s):  
Yousef M. Hamdan ◽  
Shitao Fu ◽  
Xiangmei Jiang ◽  
Yinhua Cheng ◽  
Kaixun Huang ◽  
...  
Keyword(s):  
Release Kinetics ◽  
Sebacic Acid ◽  
Gel Permeation Chromatography ◽  
Gravimetric Analysis ◽  
Thermal Gravimetric ◽  
Scanning Calorimetry ◽  
First Order ◽  
Melt Polycondensation ◽  
Model Drug

2-Octylsuccinic acid and its copolyanhydrides with sebacic acid have been synthesized by melt polycondensation, and were characterized by Fourier transform infrared spectroscopy, 1H NMR, gel permeation chromatography, differential scanning calorimetry, and thermal gravimetric analysis. In vitro studies showed that all copolymers are degradable in phosphate buffer at 37°C. The release profiles of the hydrophilic model drug ciprofloxacin hydrochloride follow first-order release kinetics.

scholarly journals Immunolocalization and molecular properties of a high molecular weight microtubule-bundling protein (syncolin) from chicken erythrocytes.

1991 ◽  
Vol 112 (4) ◽  
pp. 689-699 ◽  
Author(s):  
P Feick ◽  
R Foisner ◽  
G Wiche
Keyword(s):  
Molecular Weight ◽  
Bone Marrow Cells ◽  
Gel Permeation Chromatography ◽  
Apparent Molecular Weight ◽  
Ultrastructural Level ◽  
Temperature Dependent ◽  
Protein Map ◽  
Marginal Band ◽  
Chicken Erythrocytes

A protein of apparent molecular weight 280,000 (syncolin), which is immunoreactive with antibodies to hog brain microtubule-associated protein (MAP) 2, was purified from chicken erythrocytes. Immunofluorescence microscopy of bone marrow cells revealed the presence of syncolin in cells at all stages of erythrocyte differentiation. In early erythroblasts syncolin was diffusely distributed throughout the cytoplasm. At later stages it was found along microtubules of the marginal band, as confirmed by immunoelectron microscopy. The association of syncolin with the marginal band was dependent on the integrity of microtubules, as demonstrated by temperature-dependent de- and repolymerization or marginal band microtubules. Syncolin cosedimented in a saturable manner with microtubules assembled in vitro, and it was displaced from the polymer by salt. Brain as well as erythrocyte microtubules, reconstituted with taxol from MAP-free tubulin and purified syncolin, were aggregated into dense bundles containing up to 15 microtubules, as determined by electron microscopy. On the ultrastructural level, syncolin molecules were visualized as globular or ringlike structures, in contrast to the thin, threadlike appearance of filamentous MAPs, such as brain MAP 2. According to ultrastructural measurements and gel permeation chromatography, syncolin's molecular weight was approximately 1 x 10(6). It is suggested that syncolin's specific function is the cross-linking of microtubules in the marginal band and, by implication, the stabilization of this structure typical for nucleated (chicken) erythrocytes.

Components and Antioxidant Activity of the Polysaccharide from Streptomyces virginia H03

2008 ◽  
Vol 63 (3-4) ◽  
pp. 181-188 ◽  
Author(s):  
Feng He ◽  
Ying Yang ◽  
Guang Yang ◽  
Longjiang Yu
Keyword(s):  
Lipid Peroxidation ◽  
Molecular Weight ◽  
Antioxidant Activity ◽  
Vitamin C ◽  
Superoxide Anion ◽  
Gel Permeation Chromatography ◽  
Apparent Molecular Weight ◽  
Heat Stability ◽  
Gel Permeation

A polysaccharide was isolated from the broth of cultured Streptomyces virginia H03 which was treated by ethanol deposition and savage method to remove the protein, and was purified using Sephadex G-150 column chromatography. The components of the polysaccharide were determined by gas chromatography. The purified polysaccharide was made up of mannose, glucose and galactose, in a 2:1:1 proportion. Its average apparent molecular weight was 3.76 · 104 Da which was determined by gel permeation chromatography. In addition, several antioxidant assays were adopted to investigate the antioxidant activity of the polysaccharide in vitro. The results indicated that the purified polysaccharide showed significant antioxidant activity against superoxide anion, hydrogen peroxide and 1,1-diphenyl-2-picrylhydrazyl radical, and lipid peroxidation as with standard antioxidants such as vitamin C. Furthermore, the polysaccharide had a better heat stability than vitamin C, which suggested that the polysaccharide might be a potent useful antioxidant

scholarly journals Isolating High Antimicrobial Ability Lignin From Bamboo Kraft Lignin by Organosolv Fractionation

2021 ◽  
Vol 9 ◽  
Author(s):  
Jinyan Yun ◽  
Liao Wei ◽  
Wei Li ◽  
Duqiang Gong ◽  
Hongyu Qin ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Molecular Weight ◽  
Biological Activities ◽  
Gel Permeation Chromatography ◽  
Antimicrobial Activities ◽  
Phenolic Hydroxyl ◽  
Hydroxyl Content ◽  
Lignin Fraction

Lignin from different biomasses possess biological antioxidation and antimicrobial activities, which depend on the number of functional groups and the molecular weight of lignin. In this work, organosolv fractionation was carried out to prepare the lignin fraction with a suitable structure to tailor excellent biological activities. Gel permeation chromatography (GPC) analysis showed that decreased molecular weight lignin fractions were obtained by sequentially organosolv fractionation with anhydrous acetone, 50% acetone and 37.5% hexanes. Nuclear magnetic resonance (NMR) results indicated that the lignin fractions with lower molecular weight had fewer substructures and a higher phenolic hydroxyl content, which was positively correlated with their antioxidation ability. Both of the original lignin and fractionated lignins possessed the ability to inhibit the growth of Gram-negative bacteria (Escherichia coli and Salmonella) and Gram-positive bacteria (Streptococcus and Staphylococcus aureus) by destroying the cell wall of bacteria in vitro, in which the lignin fraction with the lowest molecular weight and highest phenolic hydroxyl content (L3) showed the best performance. Besides, the L3 lignin showed the ability to ameliorate Escherichia coli-induced diarrhea damages of mice to improve the formation of intestinal contents in vivo. These results imply that a lignin fraction with a tailored structure from bamboo lignin can be used as a novel antimicrobial agent in the biomedical field.

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