scholarly journals Thermosensitive Poloxamer-graft-Carboxymethyl Pullulan: A Potential Injectable Hydrogel for Drug Delivery

Polymers ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 3025
Author(s):  
Marieta Constantin ◽  
Bogdan Cosman ◽  
Maria Bercea ◽  
Gabriela-Liliana Ailiesei ◽  
Gheorghe Fundueanu
Keyword(s):  
Gelation Time ◽  
Poloxamer 407 ◽  
Initial Structure ◽  
Injectable Hydrogel ◽  
Grafted Copolymer ◽  
1H Nuclear Magnetic Resonance ◽  
Gelation Behavior ◽  
Model Drug ◽  
Carboxymethyl Pullulan ◽  
External Stimuli

A thermosensitive copolymer composed of amphiphilic triblock copolymer, poloxamer 407, grafted on hydrophilic pullulan with pendant carboxymethyl groups (CMP) was prepared and characterized. The structure of the new copolymer was assessed by Fourier transform infrared (FT-IR) and 1H nuclear magnetic resonance (1H NMR) spectroscopy. The content of the poloxamer in the grafted copolymer was 83.8% (w/w). The effect of the copolymer concentration on the gelation behavior was analyzed by the vertical method and rheological tests; the gel phase of the copolymer occurred at a lower concentration (11%, w/v) as compared with poloxamer (18%, w/v). The starting gelation time under the simulated physiological conditions (phosphate buffer with a pH of 7.4, at 37 °C) was sensitive on the rest temperature before the test, this being 990 s and 280 s after 24 h rest at 4 °C and 20 °C, respectively. The rheological tests evidenced a high elasticity and excellent ability of the copolymer to recover the initial structure after the removal of the applied force or external stimuli. Moreover, the hydrogel has proved a sustained release of amoxicillin (taken as a model drug) over 168 h. Taken together, the results clearly indicate that this copolymer can be used as an injectable hydrogel.

A polycation-induced secondary assembly of amphiphilic calixarene and its multi-stimuli responsive gelation behavior

2015 ◽  
Vol 51 (9) ◽  
pp. 1647-1649 ◽  
Author(s):  
Kun-Peng Wang ◽  
Yong Chen ◽  
Yu Liu
Keyword(s):  
Stimuli Responsive ◽  
Supramolecular Hydrogel ◽  
Assembly Strategy ◽  
Gelation Behavior ◽  
External Stimuli ◽  
Secondary Assembly

A calixarene-based supramolecular hydrogel with reversible or irreversible gelation behaviors in response to external stimuli constructed via a hierarchical induced assembly strategy.

scholarly journals Preparing an injectable hydrogel with sodium alginate and Type I collagen to create better MSCs growth microenvironment

e-Polymers ◽  
2019 ◽  
Vol 19 (1) ◽  
pp. 87-91 ◽  
Author(s):  
Jiankang Zhou ◽  
Kun Zhang ◽  
Shanshan Ma ◽  
Tengfei Liu ◽  
Minghao Yao ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Sodium Alginate ◽  
Type I Collagen ◽  
Gelation Time ◽  
Organ Injury ◽  
Type I ◽  
Injectable Hydrogel ◽  
Tissue Scaffold ◽  
Organ Repair

AbstractIn the past few decades, stem cell transplantation has been generally accepted as an effective method on the treatment of tissue and organ injury. However, the insufficient number of transplanted stem cells and low survival rate that caused by series of negative conditions limit the therapeutic effect. In this contribution, we developed an injectable hydrogel composed of sodium alginate (SA) and Type I collagen (ColI), as the tissue scaffold to create better growth microenvironment for the stem cells. Compared the traditional SA scaffold, the ColI/SA hydrogel inherits its biomimetic properties, and simultaneously has shorter gelation time which means less loss of the transplanted stem cells. The mesenchyma stem cell (MSC) culture experiments indicated that the ColI/SA hydrogel could prevent the MSC apoptosis and contributed to faster MSC proliferation. It is highlighted that this ColI/SA hydrogel may have potential application for tissue regeneration and organ repair as the stem cell scaffold.

scholarly journals DEVELOPMENT AND EVALUATION OF A POLOXAMER- AND CHITOSAN-BASED IN SITU GEL-FORMING INJECTABLE DEPOT

2020 ◽  
pp. 36-41
Author(s):  
Hema a Nair ◽  
NAZIA BEGUM
Keyword(s):  
Ex Vivo ◽  
Gelation Time ◽  
In Vitro Release ◽  
Aqueous Acetic Acid ◽  
Drug Content ◽  
Low Viscosity ◽  
Model Drug ◽  
Dialysis Bag

Objective: The present study is intended to investigate the applicability of poloxamer- and chitosan-based temperature induced in situ injectable gelling depot for once a week therapy as an intramuscular injection employing olanzapine as a model drug. Methods: The thermosetting gel was prepared by admixture of a solution of poloxamer P127 and a solution of olanzapine and chitosan in aqueous acetic acid. The resultant formulation was characterized for gelation temperature, gelation time, viscosity, syringeability, pH, drug content, and in vitro drug release. The in vitro release of olanzapine from the gelled depot was followed using USP paddle type II apparatus in conjunction with a dialysis bag. The gel was injected ex vivo into chicken muscle and observed by subsequent dissection. Results: The formulation was designed to have a phase transition temperature of 34°C and gelled in <10 s at 37°C. Addition of chitosan imparted favorable rheological properties to the poloxamer gel and resulted in a pseudoplastic mixture with low viscosity in the sol state and higher viscosity post gelation. The preparation had a pH of 5.4, appropriate drug content and readily passed through a 20 gauge needle. The release of olanzapine was unhindered by the dialysis bag. Following an initial bust, a sustained, zero-order release of the remainder of drug was observed up to 9 days. The injectable was found to form a compact depot when evaluated ex vivo. Conclusion: The developed system showed several features which make it a suitable vehicle for sustained intramuscular delivery of drugs.

A Comparison Study of the Effects of Ultrasonication on the Gelation Behavior between the Silk Fibroin of Domestic and Wild Silkworms

2014 ◽  
Vol 941-944 ◽  
pp. 989-993
Author(s):  
Yuan Zhou
Keyword(s):  
Bombyx Mori ◽  
Structural Transformation ◽  
Gelation Time ◽  
Random Coil ◽  
Ultrasonic Power ◽  
Comparison Study ◽  
Silk Fibroins ◽  
Gelation Behavior ◽  
Α Helix ◽  
Β Sheet

This paper was concerned with the effects of ultrasonication on the gelation behavior of silk fibroins (SF), and a comparison of Domestic and Wild silkworms was studied. The results show that: with the increase of ultrasonic power, the gelation time of domestic (Bombyx Mori) SF solution decreased sharply. But wild silkworms (Antheraea yamamai and Antheraea pernyi) SF were different, When the power of utrasonication was lower than 400-500 W, the velocity of gelation were accelerated, and when the ultrasonic power was higher than 400-500W, the gelation time were delayed. Whatever domestic or wild silkworms, the mechanism of the effects of ultrasonication on the gelation behavior was that the ultrasonication promoted the structural transformation of SF molecules from random coil or α-helix to β-sheet.

Application of Thermosensitive Poloxamer-Based Hydrogel in the Development of Transdermal Therapy Containing Herbal Medicine

2016 ◽  
Vol 719 ◽  
pp. 57-61
Author(s):  
Wen Yi Wang ◽  
Patrick Chi Leung Hui ◽  
Frency S.F. Ng ◽  
Chi Wai Kan ◽  
Clara B.S. Lau ◽  
...  
Keyword(s):  
Skin Permeation ◽  
Sol Gel ◽  
Penetration Enhancers ◽  
Poloxamer 407 ◽  
Enhancement Effect ◽  
Sol Gel Transition ◽  
Model Drug ◽  
Permeation Properties ◽  
Selection Of ◽  
Gel Transition

Poloxamer 407 exhibits remarkable reversible sol gel transition which makes it attractive and promising in the application of transdermal therapy. This study mainly reports the skin permeation properties of model drug from poloxamer 407 based transdermal hydrogel therapy with the presence of chemical penetration enhancers. Poloxamer 407 based hydrogel was shown porous structure which faciliates the diffusional release of model drug. Compared with borneol and 1,2-propanediol, azone was the most effective enhancer for gallic acid skin permeation, and 3% of azone presented the optimal enhancement effect. This study also demonstrated that the selection of enhancers is of great importance for the skin permeation of model drug.

scholarly journals The Thermal Gelation Behavior and Performance Evaluation of High Molecular Weight Nonionic Polyacrylamide and Polyethyleneimine Mixtures for Indepth Water Control in Mature Oilfields

2020 ◽  
Author(s):  
Qin Yi ◽  
Ruiquan Liao ◽  
Shunshe Luo ◽  
Junliang Li
Keyword(s):  
Ph Value ◽  
Gelation Time ◽  
Quadratic Model ◽  
Dimensional Structure ◽  
Polymer Gel ◽  
Water Control ◽  
Good Reliability ◽  
Thermal Gelation ◽  
Gelation Behavior ◽  
Gel System

A delayed crosslinked polymer gel was developed for indepth water control in mature oilfields. The thermal gelation behavior of nonionic polyacrylamide (NPAM) and PEI was investigated, and sodium citrate (NaCit) was selected as a new retarder to prolong the gelation time. The gelation performance of NPAM/PEI gel system can be adjusted by the variation of NPAM or PEI concentration, and a quadratic model was developed by statistical analysis, which predict the gelation time of NPAM/PEI gel system. The obtained model showed high significance and good reliability as suggested by the F-ratio of 175.16 and high adjusted R-square value (0.9732). The decrease of the initial pH value of gelling solution leads to the weaker gel viscosity and longer gelation time due to the protonation of amine groups on the PEI chains. Increasing temperature resulted in higher gel viscosity but shorter gelation time. The addition of NaCit showed a good delayed gelation effect on the NPAM/PEI gel system, and the gel system in the presence of NaCit exhibited a good compatibility with injected and formation water. A dense three-dimensional structure was observed in matured NPAM/PEI/NaCit gel, and it could keep stable below 150℃. The gel system could effectively reduce the permeability (&gt;95%) and restricted the flow of water after matured in natural cores.

scholarly journals Dynamic and static gelation behavior of phenol formaldehyde resin gel system in ampoule bottles and porous media

2020 ◽  
Vol 75 ◽  
pp. 55
Author(s):  
Haiyang Yu ◽  
Wenjuan Ji ◽  
Jiapeng Zheng
Keyword(s):  
Porous Media ◽  
Phenol Formaldehyde ◽  
Gelation Time ◽  
Quantitative Relationship ◽  
Phenol Formaldehyde Resin ◽  
Formaldehyde Resin ◽  
Polymer Gel ◽  
Gel Treatment ◽  
Key Factor ◽  
Gelation Behavior

The dynamic and static gelation process in porous media of the phenol formaldehyde resin gel was studied for successful application in conformance control and water shutoff. Shear rate was the most important factor affecting the dynamic gelation in porous media. Compare to static gelation in ampoule bottles and in porous media, the dynamic gelation time in porous media was extended by 2–6 times. The ability of migration and plugging after dynamic gelation was controlled by system concentration. The porous media permeability was the key factor for dynamic gelling time and strength. The quantitative relationship equation was established between dynamic gelling strength and permeability to choose the appropriate permeability for polymer gel treatment.

Development of In Situ Gel for Oral Application

2014 ◽  
Vol 1060 ◽  
pp. 66-69
Author(s):  
Suwannee Panomsuk ◽  
Pimchanok Nakprasong ◽  
Suthi On Tanpichai ◽  
Sasithorn Chin-Aramrungruang
Keyword(s):  
Drug Release ◽  
Buccal Mucosa ◽  
Sol Gel ◽  
Gel Strength ◽  
Medical Product ◽  
Poloxamer 407 ◽  
In Situ Gel ◽  
Model Drug ◽  
Gel Temperature

In situ gel, a new concept of medical product for oral applications was developed using Poloxamer 407 (P) and Carbopol 934 (C) which are thermo-and pH-sensitive sol-gel polymers, respectively. The formulations were evaluated for the physical appearance, pH, viscosity, sol-gel temperature, gel strength and buccal mucoadhesive (adhesion to porcine buccal mucosa). Benzalkonium chloride (BzCl) 0.1% w/v was added in the suitable formulations as a model drug. Formulations containing 20% P (pH = 7.1) and 20% P + 0.6% C (pH = 5.0) showed good physical appearances which turned to gels in buccal conditions. Their mucoadhesive force to porcine buccal mucosa were higher than formulations containing 10 and 15 % P(p<0.05). The present of 0.6 % C in the formulation did not affect gel strength but tended to increase mucoadhesive properties. The release of BzCl from the formulations was performed using Franz diffusion cell at 37°C for 1 hour. There were no different in drug release from both formulations(p<0.05), the amount of drug release was 11.7% ± 4.4 and 10.9% ± 0.8, respectively. In conclusion, formulation containing 20% P and 0.6% C has revealed the most suitable properties as in situ gel for buccal mucosa applications, the release of BzCl was 10.9% ± 0.8 within 1 hour.

Synthesis and characterization of a novel injectable alginate–collagen–hydroxyapatite hydrogel for bone tissue regeneration

2015 ◽  
Vol 3 (15) ◽  
pp. 3081-3090 ◽  
Author(s):  
Stephanie T. Bendtsen ◽  
Mei Wei
Keyword(s):  
Bone Regeneration ◽  
Bone Tissue ◽  
Tissue Regeneration ◽  
Gelation Time ◽  
Bone Tissue Regeneration ◽  
Synthesis And Characterization ◽  
Injectable Hydrogel ◽  
Surgical Setting ◽  
Hydrogel System

This novel fabrication process allowed for the development of an injectable hydrogel system with a gelation time suitable for a surgical setting and components necessary for promoting enhanced bone regeneration.

scholarly journals An Injectable Composite Gelatin Hydrogel with pH Response Properties

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Baoguo Chen ◽  
Xiaohong Hu
Keyword(s):  
Gelation Time ◽  
Viscoelastic Behavior ◽  
Invasive Procedure ◽  
Physical Interaction ◽  
Step Method ◽  
Injectable Hydrogel ◽  
Response Properties ◽  
Ph Response ◽  
In Situ Hydrogel

On account of minimally invasive procedure and of filling irregular defects of tissues, injectable hydrogels are increasingly attractive in biomedical fields. However, traditional hydrogel formed by simple physical interaction or in situ crosslinking had inevitably some drawbacks such as low mechanical strength and lack of multifunctional properties. Though many investigations had successfully modified traditional injectable hydrogel to obtain both mechanical and functional properties, an acetalated β-cyclodextrin (Ac-β-CD) nanoparticle composite injectable hydrogel designed in the research was another effective and efficient choice to solve the drawbacks. First of all, gelatin derivative (G-AA) and Ac-β-CD were synthesized to prepare hydrogel and nanoparticle, respectively. In order to ensure good compatibility between nanoparticle and macromonomer and provide crosslink points between nanoparticle and macromonomer, G-AA was simultaneously functionalized onto the surface of Ac-β-CD nanoparticle during the fabrication of Ac-β-CD nanoparticle using one-step method. Finally, injectable composite hydrogel was obtained by photoinitiated polymerization in situ. Hydrogel properties like gelation time and swelling ratio were investigated. The viscoelastic behavior of hydrogels confirmed that typical characteristics of crosslinked elastomer for all hydrogel and nanoparticle in hydrogel could improve the mechanical property of hydrogel. Moreover, the transparency with time had verified obvious acid-response properties of hydrogels.

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