scholarly journals Azo-polysiloxane micelles charged with nifedipine

2013 ◽  
Vol 11 (9) ◽  
pp. 1431-1438 ◽  
Author(s):  
Anca-Irina Prisacaru ◽  
Silvia Grama ◽  
Ana Durdureanu-Angheluta ◽  
Mariana Pinteala ◽  
Nicolae Hurduc

AbstractAbstract One recent aspect of the research study on polymers is their capability to respond to external stimuli. Of importance are photosensitive polymers due to their application in drug delivery systems, sensors, therapeutic devices or optoelectronic switches. The present paper focuses on the azo-polysiloxane micelles capacity charged with hydrophobic drugs, such as nifedipine. Azo-polysiloxanes modified with quaternary ammonium groups and which are capable to generate photo-sensitive micelles were synthesized and characterized by 1H-NMR, UV-VIS and fluorescence spectroscopy. The critical concentration of the micellar aggregation (CCA) was evaluated as was the nifedipine embedding capacity. The CCA values were influenced only by the hydrophobic/hydrophilic balance and not by the chemical structure of the quaternary ammonium groups. The disaggregation capacity of the micelles under UV irradiation was investigated as well, and the best results were obtained for the samples with higher azobenzene content. The DLS measurements evidenced micelles diameters situated in the optimum range domain (70–130 nm). The capacity to incorporate nifedipine inside the micelles was demonstrated. The micelles proved to be stable in time, 21 days after preparation with the diameter having constant values. Graphical abstract

2020 ◽  
Vol 21 (18) ◽  
pp. 6617 ◽  
Author(s):  
Angela Fabiano ◽  
Denise Beconcini ◽  
Chiara Migone ◽  
Anna Maria Piras ◽  
Ylenia Zambito

As a natural polysaccharide, chitosan has good biocompatibility, biodegradability and biosecurity. The hydroxyl and amino groups present in its structure make it an extremely versatile and chemically modifiable material. In recent years, various synthetic strategies have been used to modify chitosan, mainly to solve the problem of its insolubility in neutral physiological fluids. Thus, derivatives with negative or positive fixed charge were synthesized and used to prepare innovative drug delivery systems. Positively charged conjugates showed improved properties compared to unmodified chitosan. In this review the main quaternary ammonium derivatives of chitosan will be considered, their preparation and their applications will be described to evaluate the impact of the positive fixed charge on the improvement of the properties of the drug delivery systems based on these polymers. Furthermore, the performances of the proposed systems resulting from in vitro and ex vivo experiments will be taken into consideration, with particular attention to cytotoxicity of systems, and their ability to promote drug absorption.


Gels ◽  
2020 ◽  
Vol 6 (3) ◽  
pp. 20 ◽  
Author(s):  
Sobhan Ghaeini-Hesaroeiye ◽  
Hossein Razmi Bagtash ◽  
Soheil Boddohi ◽  
Ebrahim Vasheghani-Farahani ◽  
Esmaiel Jabbari

Nanogels, or nanostructured hydrogels, are one of the most interesting materials in biomedical engineering. Nanogels are widely used in medical applications, such as in cancer therapy, targeted delivery of proteins, genes and DNAs, and scaffolds in tissue regeneration. One salient feature of nanogels is their tunable responsiveness to external stimuli. In this review, thermosensitive nanogels are discussed, with a focus on moieties in their chemical structure which are responsible for thermosensitivity. These thermosensitive moieties can be classified into four groups, namely, polymers bearing amide groups, ether groups, vinyl ether groups and hydrophilic polymers bearing hydrophobic groups. These novel thermoresponsive nanogels provide effective drug delivery systems and tissue regeneration constructs for treating patients in many clinical applications, such as targeted, sustained and controlled release.


2021 ◽  
Author(s):  
Hina Shoukat ◽  
Khuda Buksh ◽  
Sobia Noreen ◽  
Fahad Pervaiz ◽  
Irsah Maqbool

Hydrogels are 3D crosslinked polymer matrices having a colossal tendency to imbibe water and exhibit swelling under physiological conditions without deformation in their hydrophilic network. Hydrogels being biodegradable and biocompatible, gained consideration due to some unique characteristics: responsiveness to external stimuli (pH, temperature) and swelling in aqueous solutions. Hydrogels offer a promising option for various pharmaceutical and biomedical applications, including tissue-specific drug delivery at a predetermined, controlled rate. This article presents a brief review of the recent and fundamental advances to design hydrogels, the swelling and deswelling mechanism, various crosslinking methods and their use as an intelligent carrier in the pharmaceutical field. Recent applications of hydrogels are also briefly discussed and exemplified.


2015 ◽  
Vol 3 (14) ◽  
pp. 2770-2777 ◽  
Author(s):  
Nicky Thomas ◽  
Dong Dong ◽  
Katharina Richter ◽  
Mahnaz Ramezanpour ◽  
Sarah Vreugde ◽  
...  

The anti-biofilm effect of drug delivery systems composed of the antiseptic quaternary ammonium compound cetylpyridinium chloride (CPC) and cholesterol was evaluated inStaphylococcus aureusbiofilm.


RSC Advances ◽  
2017 ◽  
Vol 7 (32) ◽  
pp. 19604-19610 ◽  
Author(s):  
Xiaofang Qi ◽  
Lu Xiong ◽  
Jing Peng ◽  
Dongyan Tang

One major issue in thermosensitive drug delivery systems is the remote, repeatable control of temperature in vivo through external stimuli such as light, ultrasound, and magnetic field.


Nanomedicine ◽  
2020 ◽  
Vol 15 (27) ◽  
pp. 2707-2727
Author(s):  
Filippo Pinelli ◽  
Óscar Fullana Ortolà ◽  
Pooyan Makvandi ◽  
Giuseppe Perale ◽  
Filippo Rossi

In recent years, nanogels have emerged as promising drug delivery vehicles; their ability in holding active molecules, macromolecules and drugs, together with the capability to respond to external stimuli, makes them a suitable tool for a wide range of applications. These features allow nanogels to be exploited against many challenges of nanomedicine associated with different kinds of pathologies which require the use of specific drug delivery systems. In this review our aim is to give the reader an overview of the diseases that can be treated with nanogels as drug delivery systems, such as cancer, CNS disorders, cardiovascular diseases, wound healing and other diseases of human body. For all of these pathologies, biological in vivo assays can be found in the literature and in this work. We focus on the peculiarities of these nanogels, highlighting their features and their advantages in respect to conventional treatments.


2021 ◽  
Vol 10 (1) ◽  
pp. 933-953
Author(s):  
Baranya Murugan ◽  
Suresh Sagadevan ◽  
Is Fatimah ◽  
Won-Chun Oh ◽  
Mohd Abd Motalib Hossain ◽  
...  

Abstract Nanomedicine is ongoing current research in the applications of nanotechnology for cancer therapy. Simply from a technology perspective, this field of research has an enormous broadening and success to date. Recently, nanomedicine has also made inroads in the treatment of cancer. Stimuli-responsive nanoparticles are an emerging field of research because its targeting capacity is of great interest in the treatment of cancer. The responsive nanoparticles are efficient in encountering different internal biological stimuli (acidic, pH, redox, and enzyme) and external stimuli (temperature, ultrasounds, magnetic field, and light), which are used as smart nanocarriers for delivery of the chemotherapeutic and imaging agents for cancer therapy. In-depth, the responsive nanocarrier that responds to the biological cues is of pronounced interest due to its capability to provide a controlled release profile at the tumor-specific site. The outlook of this review focuses on the stimuli-responsive nanocarrier drug delivery systems in sequence to address the biological challenges that need to be evaluated to overcome conventional cancer therapy.


Author(s):  
G.E. Visscher ◽  
R. L. Robison ◽  
G. J. Argentieri

The use of various bioerodable polymers as drug delivery systems has gained considerable interest in recent years. Among some of the shapes used as delivery systems are films, rods and microcapsules. The work presented here will deal with the techniques we have utilized for the analysis of the tissue reaction to and actual biodegradation of injectable microcapsules. This work has utilized light microscopic (LM), transmission (TEM) and scanning (SEM) electron microscopic techniques. The design of our studies has utilized methodology that would; 1. best characterize the actual degradation process without artifacts introduced by fixation procedures and 2. allow for reproducible results.In our studies, the gastrocnemius muscle of the rat was chosen as the injection site. Prior to the injection of microcapsules the skin above the sites was shaved and tattooed for later recognition and recovery. 1.0 cc syringes were loaded with the desired quantity of microcapsules and the vehicle (0.5% hydroxypropylmethycellulose) drawn up. The syringes were agitated to suspend the microcapsules in the injection vehicle.


Sign in / Sign up

Export Citation Format

Share Document