China 
Africa 
Explore chapters and articles related to this topic
Magnetic Nanoparticles for Cancer Diagnosis
Published in D. Sakthi Kumar, Aswathy Ravindran Girija, Bionanotechnology in Cancer, 2023
R. G. Aswathy, D. Sakthi Kumar
Encapsulation technique is also another technique adapted for the development of integrated imaging agents. PET/MRI dual-modality imaging probe with IO NPs and 68Ga using specially designed functional amphiphiles was developed by encapsulation method for targeted lymph nodes imaging [93]. Superparamagnetic iron oxide nanoparticle (SPION) with negative MRI contrast was radiolabeled with 67Ga (SPECT radioisotope) or with 64Cu (PET radioisotope) at high temperature via ligand-free radiolabeling. Stable biocompatible multimodal imaging probe for PET/SPECT-MRI was developed by using sterically stabilized SPIONs with diblock copolymers with methoxypolyethylene glycol (MPEG) or primary amine NH2 end groups [94]. Design of physiologically stable radiolabeled MNPs with a tunable functional end group on the SPIONs facilitates multimodal PET/SPECT-MRI agent on T2 contrast MRI probe.
Liquorice and Chinese herbal medicine
Published in Vivienne Lo, Michael Stanley-Baker, Dolly Yang, Routledge Handbook of Chinese Medicine, 2022
The special place given to liquorice may possibly be explained by an examination of the chemistry of the glycyrrhizin molecule. As mentioned previously, one half of the molecule (the sugar half) is hydrophilic, while the other half (the steroid part) is hydrophobic. Molecules of this type are known as amphiphilic. An aqueous environment causes glycyrrhizin molecules to aggregate rather than dissolve, probably in the form of a sphere (although cylindrical aggregates are possible) (Zhang, Wang, Wang and Yu 2006) with the hydrophobic part of the molecules pointing in, and the sugar part on the outside hydrogen bonding to water molecules in the solvent. There is good physical evidence to support this view. A mass spectroscopic study with glycyrrhetinic acid revealed that, in the spectrometer, aggregates of up to eight molecules form readily (Borisenko, Lekar, Vetova et al. 2016).
Organic Nanocarriers for Brain Drug Delivery
Published in Carla Vitorino, Andreia Jorge, Alberto Pais, Nanoparticles for Brain Drug Delivery, 2021
Marlene Lúcio, Carla M. Lopes, Eduarda Fernandes, Hugo Gonẹalves, Maria Elisabete C. D. Real Oliveira
Micelles are self-assembly aggregates with 5–50 nm of amphiphilic agents (lipidic or polymeric) which occur above a well-defined concentration which is called the critical micelle concentration (CMC). Unlike liposomes or POs which are vesicles containing an aqueous core, micelles possess hydrophilic portions turned towards aqueous surroundings and a hydrophobic core made of the hydrophobic portions of the amphiphilic agents (Fig. 4.1) [2]. As described before, although using the same type of amphiphilic constituents, whether an amphiphile is assembled in a micelle or in a vesicle, it depends on several parameters, such as concentration, molecular weight, geometry of the amphiphilic block copolymers or amphiphilic lipids or the ratio of the different blocks.
Investigating the self-assembling of nicotinic hydrazide-based amphiphile into nano-range vesicles and its amphotericin B loading applications
Published in Drug Delivery, 2023
Kashif Hussain, Abdul Jabbar, Khwaja Ali Hasan, Muneeb Ali, Zaheer Ul-Haq, Muhammad Raza Shah, Saeed Ahmad Khan, Md Abdur Rashid, Mohsin Kazi, Muhammad Naseer Abbas
For proper characterization of a nano-drug delivery system, its capability of entrapping drug amounts is very important. The amphotericin-B entrapment efficiency by NODNH-16 and NODNH-18-based vesicles was determined following the separation of the un-entrapped drug by cold centrifugation. The entrapped drug in the sedimented vesicular pellet was determined by dissolving it in methanol and subsequent reading on UV-spectroscopy at a maximum wavelength of 405 nm. The amount of drug entrapped in newly synthesized surfactant NODNH-18 was 68.63 ± 3.43% and similarly, the drug entrapment efficiency of NODNH-16-based vesicles was 60.89 ± 2.88% (Table 1). Among other factors, the aliphatic tail of an amphiphile also affects drug entrapment efficiency. The comparatively greater drug entrapment efficiency of NODNH-18 may be due to its larger lipophilic carbon chain length which increases its lipophilicity and molecular weight (Hao et al., 2002).
Multifunctional and stimuli-responsive nanocarriers for targeted therapeutic delivery
Published in Expert Opinion on Drug Delivery, 2021
Nanocarriers which can change their certain property upon endogenous or exogenous stimuli, offered a wide range of biomedical applications including controlled release of therapeutics directly at the desired site thereby reducing side effects in the surrounding healthy tissue [114]. Such nanocarriers are referred to as stimuli-responsive nanocarriers, which have attracted enormous attention in recent years in the field of targeted drug delivery from various research groups throughout the world. Stimuli-responsive nanocarriers are generally made of a hydrophobic inner core and a hydrophilic or amphiphilic outer shell, which is usually an amphiphilic stimulus-responsive polymer sensitive to various endogenous or exogenous stimuli. The amphiphilic compound can be any of the natural lipids or lipid like materials or surfactants which are usually pH, redox, temperature, light, enzyme, or magnetic responsive polymers. For some nanocarriers, the hydrophobic part of amphiphilic polymers is modified with cationic groups for conjugating anionic agents such as nucleic acids in the hydrophobic core [115]. In addition, these nanocarriers sometime contain another component such as a targeting ligand or adhesion ligand which is specific to its receptor on target cells or tissues. Various stimuli-sensitive nanocarriers developed for drug and gene delivery application have been summarized in Table 2 [34,38,39,40,116–126]. We will be discussing various endogenous or exogenous stimuli-responsive nanocarriers for targeted therapeutic delivery applications.
Vesicle formation mechanisms: an overview
Published in Journal of Liposome Research, 2021
According to symmetry and charge distribution, molecules can be roughly divided into two categories, i.e. polar and non-polar. Polar molecules are soluble in a polar solvent (e.g. ethanol in water) and insoluble in a non-polar solvent (e.g. oil in water), and vice versa (Lasic 1993). Some molecules (such as phospholipids, surfactants, and copolymers) contain both polar and non-polar groups, commonly known as amphiphiles. As these amphiphiles possess both hydrophilic and hydrophobic interactions, they can self-assemble and form ordered structures in an aqueous milieu. Depending on amphiphiles molecular shape, their self-assembly in water results in several phases, e.g. some organise into small spherical, globular or cylindrical micelles, while the others appear to assemble into spherical vesicles, bicontinuous cubic phases or planner bilayers (Lasic 1993, Sterling 1993, Guida 2010).