scholarly journals In situ Rheo-GISANS of triblock copolymers: gelation and shear effects on quasi-crystalline structures at interfaces

RSC Advances ◽  
2015 ◽  
Vol 5 (126) ◽  
pp. 104164-104171 ◽  
Author(s):  
Gemma E. Newby ◽  
Erik B. Watkins ◽  
Daniel Hermida Merino ◽  
Paul A. Staniec ◽  
Oier Bikondoa
Keyword(s):  
Drug Delivery ◽  
Block Copolymer ◽  
Triblock Copolymers ◽  
Polymeric Systems ◽  
Crystalline Structures ◽  
Shear Effects

The behaviour of polymeric systems at surfaces and under flow is very important in many applications, from drug delivery to lubrication. Here, we have studied the thermotropic phases formed by a model tri-block copolymer using in situ Rheo-GISANS.

In situ gelling stimuli-sensitive block copolymer hydrogels for drug delivery

2008 ◽  
Vol 127 (3) ◽  
pp. 189-207 ◽  
Author(s):  
Chaoliang He ◽  
Sung Wan Kim ◽  
Doo Sung Lee
Keyword(s):  
Drug Delivery ◽  
Block Copolymer ◽  
Stimuli Sensitive ◽  
In Situ Gelling

scholarly journals A Recent Overview: In Situ Gel Smart Carriers for Ocular Drug Delivery

2021 ◽  
Vol 11 (6-S) ◽  
pp. 195-205
Author(s):  
Mandeep Singh ◽  
Dhruv Dev ◽  
D.N. Prasad
Keyword(s):  
Drug Delivery ◽  
Delivery Systems ◽  
Eye Drops ◽  
Adhesive Properties ◽  
In Situ Gel ◽  
Temperature Changes ◽  
Polymeric Systems ◽  
Protective Layers ◽  
In Situ Gelling

Delivery of the drug to the ocular area is blocked by the protective layers covering the eyes; it has always been a major problem to find effective bioavailability of the active drug in the ocular area due to the short duration of precorneal majority ocular stay. Direct delivery systems combine as well as oil, solution, and suspension, as a result, many delivery systems are not able to effectively treat eye diseases. Many works have been done and are being done to overcome this problem one of which is to use in-situ to build polymeric systems. Ocular In-situ gelling systems are a new class of eye drug delivery systems that are initially in solution but are quickly transformed into a viscous gel when introduced or inserted into an ocular cavity where active drugs are released continuously. This sol-to-gel phase conversion depends on a variety of factors such as changes in pH, ion presence, and temperature changes. Post-transplanting gel selects viscosity and bio-adhesive properties, which prolongs the gel's stay in the ocular area and also releases the drug in a long and continuous way unlike conventional eye drops and ointments. This review is a brief overview of situ gels, the various methods of in situ gelling systems, the different types of polymers used in situ gels, their gel-based methods, and the polymeric testing of situ gel. Keywords: In-situ gel, Polymers, and ion triggered in-situ gel, Mechanism, Evaluation parameters

Mixtures of triblock copolymers E62P39E62 and E137S18E137Potential for drug delivery from in situ gelling micellar formulations

2007 ◽  
Vol 328 (1) ◽  
pp. 95-98 ◽  
Author(s):  
M. Elenir N. Pinho ◽  
Flávia de M.L.L. Costa ◽  
Fernando B.S. Filho ◽  
Nagila M.P.S. Ricardo ◽  
Stephen G. Yeates ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Triblock Copolymers ◽  
In Situ Gelling

Scaffolds for Drug Delivery in Tissue Engineering

2008 ◽  
Vol 1 (2) ◽  
pp. 113-123 ◽  
Author(s):  
Vikas V. Gaikwad ◽  
Abasaheb B. Patil ◽  
Madhuri V. Gaikwad
Keyword(s):  
Drug Delivery ◽  
Tissue Engineering ◽  
Heart Diseases ◽  
Cartilage Regeneration ◽  
Tissue Growth ◽  
The Body ◽  
Patient Specific ◽  
In Situ Gel ◽  
Heart Muscle Cells

Scaffolds are used for drug delivery in tissue engineering as this system is a highly porous structure to allow tissue growth.  Although several tissues in the body can regenerate, other tissue such as heart muscles and nerves lack regeneration in adults. However, these can be regenerated by supplying the cells generated using tissue engineering from outside. For instance, in many heart diseases, there is need for heart valve transplantation and unfortunately, within 10 years of initial valve replacement, 50–60% of patients will experience prosthesis associated problems requiring reoperation. This could be avoided by transplantation of heart muscle cells that can regenerate. Delivery of these cells to the respective tissues is not an easy task and this could be done with the help of scaffolds. In situ gel forming scaffolds can also be used for the bone and cartilage regeneration. They can be injected anywhere and can take the shape of a tissue defect, avoiding the need for patient specific scaffold prefabrication and they also have other advantages. Scaffolds are prepared by biodegradable material that result in minimal immune and inflammatory response. Some of the very important issues regarding scaffolds as drug delivery systems is reviewed in this article.

Biopolymers with Medical Applications Optimized method for obtaining chitosan-based delivery systems

2018 ◽  
Vol 69 (7) ◽  
pp. 1756-1759 ◽  
Author(s):  
Luminita Confederat ◽  
Iuliana Motrescu ◽  
Sandra Constantin ◽  
Florentina Lupascu ◽  
Lenuta Profire
Keyword(s):  
Drug Delivery ◽  
Drug Delivery Systems ◽  
Average Diameter ◽  
Delivery Systems ◽  
Cross Linking ◽  
Low Molecular Weight ◽  
Polymeric Systems ◽  
Chitosan Microparticles ◽  
Degree Of Swelling

The aim of this study was to optimize the method used for obtaining microparticles based on chitosan � a biocompatible, biodegradable, and nontoxic polymer, and to characterize the developed systems. Chitosan microparticles, as drug delivery systems were obtained by inotropic gelation method using pentasodiumtripolyphosphate (TPP) as cross-linking agent. Chitosan with low molecular weight (CSLMW) in concentration which ranged between 0.5 and 5 %, was used while the concentration of cross-linking agent ranged between 1 and 5%. The characterization of the microparticles in terms of shape, uniformity and adhesion was performed in solution and dried state. The size of the microparticles and the degree of swelling were also determined. The structure and the morphology of the developed polymeric systems were analyzed by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM).The average diameter of the chitosan microparticles was around 522 �m. The most stable microparticles were obtained using CSLMW 1% and TPP 2% or CSLMW 0.75%and TPP 1%. The micropaticles were spherical, uniform and without flattening. Using CSLMW in concentration of 0.5 % poorly cross-linked and crushed microparticles have been obtained at all TPP concentrations. By optimization of the method, stable chitosan-based micropaticles were obtained which will be used to develop controlled release systems for drug delivery.

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