Synthesis and Solution Isomerization of Water-Soluble Au9 Nanoclusters Prepared by Nuclearity Conversion of [Au11(PPh3)8Cl2]Cl

Nanoscale ◽  
2021 ◽  
Author(s):  
William Ndugire ◽  
Mingdi Yan

Water-soluble gold nanoclusters (AuNCs) are popular in biomedical applications such as bioimaging, labelling, drug delivery, and biosensing. Despite their widespread applications, the synthesis of water-soluble phosphine-capped AuNCs is not as...

Pharmaceutics ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 495 ◽  
Author(s):  
Hakkarainen ◽  
Kõrkjas ◽  
Laidmäe ◽  
Lust ◽  
Semjonov ◽  
...  

We investigated nozzleless ultrasound-enhanced electrospinning (USES) as means to generate nanofibrous drug delivery systems (DDSs) for pharmaceutical and biomedical applications. Traditional electrospinning (TES) equipped with a conventional spinneret was used as a reference method. High-molecular polyethylene oxide (PEO) and chitosan were used as carrier polymers and theophylline anhydrate as a water-soluble model drug. The nanofibers were electrospun with the diluted mixture (7:3) of aqueous acetic acid (90% v/v) and formic acid solution (90% v/v) (with a total solid content of 3% w/v). The fiber diameter and morphology of the nanofibrous DDSs were modulated by varying ultrasonic parameters in the USES process (i.e., frequency, pulse repetition frequency and cycles per pulse). We found that the USES technology produced nanofibers with higher fiber diameter (402 ± 127 nm) than TES (77 ± 21 nm). An increase of a burst count in USES increased the fiber diameter (555 ± 265 nm) and the variation in fiber size. The slight-to-moderate changes in a solid state (crystallinity) were detected when compared the nanofibers generated by TES and USES. In conclusion, USES provides a promising alternative for aqueous-based fabrication of nanofibrous DDSs for pharmaceutical and biomedical applications.


2015 ◽  
Vol 18 (3) ◽  
pp. 170-180
Author(s):  
Anh Thi Tram Tu ◽  
Huy Thuc Ha

Highly deacetylated chitosan (CS) reacted with anhydride acetic (Ac2O) to produce chitosan with various degree of deacetylation (DDA) depending on the CS/Ac2O ratios. The structure of products was characterized by FT-IR, 1H NMR, 13C NMR, and the molecular weight was identified by GPC. The DDA of products decreases as the CS/Ac2O ratio increases. The products with less than 80 % DDA were soluble in water with a wide pH range. The water-soluble chitosan can be used in many biomedical applications such as manufacturing drug delivery systems or functionalized iron oxide nanoparticles.


2021 ◽  
Vol 27 ◽  
Author(s):  
Nasrullah Shah ◽  
Manzoor Hussain ◽  
Touseef Rehan ◽  
Abbas Khan ◽  
Zubair Ullah Khan

: Polyethylene glycols (PEG) are water-soluble nonionic polymeric molecules. PEG and PEG-based materials are used for various important applications such as solvents, adhesives, adsorbents, drug delivery agents, tissue engineering scaffolds, etc. The coating of nanoparticles with PEG forms core-shell nanoparticles. The PEG-based core-shell nanoparticles are synthesized for the development of high-quality drug delivery systems. In the present review, we first explained the basics and various applications of PEGs and PEG-based composites materials and then concentrated on the PEG-based core-shell nanoparticles for biomedical applications specifically their use in drug delivery.


Author(s):  
Wiktoria Tomal ◽  
Joanna Ortyl

Light-initiated polymerization processes are currently an important tool in various industrial fields. The advancement of technology has resulted in the use of photopolymerization in various biomedical applications, such as the production of 3D hydrogel structures, the encapsulation of cells, and in drug delivery systems. The use of photopolymerization processes requires an appropriate initiating system which, in biomedical applications, must meet additional criteria: high water solubility, non-toxicity to cells, and compatibility with visible low-power light sources. This article is a literature review on those compounds that act as photoinitiators of photopolymerization processes in biomedical applications. The division of initiators according to the method of photoinitiation was described and the related mechanisms were discussed. Examples from each group of photoinitiators are presented, and their benefits, limitations and applications are outlined.


Polymers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1073 ◽  
Author(s):  
Wiktoria Tomal ◽  
Joanna Ortyl

Light-initiated polymerization processes are currently an important tool in various industrial fields. The advancement of technology has resulted in the use of photopolymerization in various biomedical applications, such as the production of 3D hydrogel structures, the encapsulation of cells, and in drug delivery systems. The use of photopolymerization processes requires an appropriate initiating system that, in biomedical applications, must meet additional criteria such as high water solubility, non-toxicity to cells, and compatibility with visible low-power light sources. This article is a literature review on those compounds that act as photoinitiators of photopolymerization processes in biomedical applications. The division of initiators according to the method of photoinitiation was described and the related mechanisms were discussed. Examples from each group of photoinitiators are presented, and their benefits, limitations, and applications are outlined.


INDIAN DRUGS ◽  
2021 ◽  
Vol 58 (02) ◽  
pp. 7-17
Author(s):  
Smita T. Kumbhar ◽  
◽  
Shitalkumar S. Patil ◽  
Manish S. Bhatia ◽  
Yogesh S. Thorata ◽  
...  

Polysaccharides demonstrate a wide diversity in their structural features as well as physicochemical properties owing to a variety of functional groups, chemical structure and a broad array of molecular mass. The most important feature of modified polysaccharides is their amphiphilic character which allows the application of these conjugates as an emulsifier, modifiers of surface in liposomes and micro/ nanoparticles, viscosity modifiers and drug delivery vehicles. Recently, the lipophilic modification of polysaccharides, which serve as a nano-container for water-insoluble or poorly water-soluble drugs, has gained attention in the biomedical applications due to their ability to form self-assembled nanoparticles. The natural polysaccharides are readily available, stable, biodegradable, economical, safe and biocompatible. It is difficult to synthesize compounds with such diversity in characteristics. In recent decades, many researchers have taken interest in polysaccharides and their derivatives for use in nanoparticulate systems. This review focuses on the chemical modification of mono and polysaccharides and the mechanisms involved in the formation of polysaccharide-based nanoparticles


2016 ◽  
Vol 7 ◽  
pp. 1278-1283 ◽  
Author(s):  
Silvia Varela-Aramburu ◽  
Richard Wirth ◽  
Chian-Hui Lai ◽  
Guillermo Orts-Gil ◽  
Peter H Seeberger

Gold nanoclusters are small (1–3 nm) nanoparticles with a high surface area that are useful for biomedical studies and drug delivery. The synthesis of small, surface-functionalized gold nanoclusters is greatly dependent on the reaction conditions. Here, we describe a straightforward, efficient and robust room temperature one-pot synthesis of 2 nm gold nanoclusters using thioglucose as a reducing and stabilizing agent, which was discovered by serendipity. The resultant monodisperse gold nanoclusters are more stable than those generated using some other common methods. The carboxylic acid contained in the stabilizing agent on the cluster surface serves as anchor for nanocluster functionalization. Alternatively, the addition of thiols serves to functionalize the nanoclusters. The resulting non-cytotoxic nanoclusters are taken up by cells and constitute a tuneable platform for biomedical applications including drug delivery.


Author(s):  
Kamble Ravindra K. ◽  
Chauhan Chetan S. ◽  
Kamble Priyadarshani R. ◽  
Naruka Pushpendra S.

The main aim of the present work was to develop the microcapsules of tramadol hydrochloride for the oral sustained release drug delivery. Tramadol hydrochloride a BCS class I drug a centrally acting synthetic analgesic was complexed with Indion 254 ion exchange resin. The microcapsules were prepared by encapsulating the prepared resinates by o/o solvent evaporation technique. In the investigation 32 full factorial design was used to investigate the joint influence of two formulation variable amount of eudragit RS 100 and plasticized PEG 400. The results of multiple linear regression analysis indicated that for obtaining a sustained release drug delivery the optimum concentrations of both the plasticizer and coating solution to be used. The factorial models were used to prepare optimized microcapsules and optimized formulations showed sustained release profiles for the extended period of more than 12 hrs. From the present investigations concluded that resinate microcapsules of highly water soluble drug can provide controlled release of drug for extended period.Key Words: Tramadol hydrochloride, ion exchange resinate, microcapsules, sustained release


Author(s):  
Preethi Sudheer ◽  
Koushik Y ◽  
Satish P ◽  
Uma Shankar M S ◽  
R S Thakur

As a consequence of modern drug discovery techniques, there has been a steady increase in the number of new pharmacologically active lipophilic compounds that are poorly water soluble and solubility is one of the most important parameter to achieve desired concentration of drug in systemic circulation for therapeutic response. It is a great challenge for pharmaceutical scientist to convert those molecules into orally administered formulation with sufficient bioavailability.  Among the several approaches to improve oral bioavailability of these molecules, Self-micron emulsifying drug delivery system (SMEDDS) is one of the approaches usually used to improve the bioavailability of hydrophobic drugs. However, conventional SMEDDS are mostly prepared in a liquid form, which can have several disadvantages. Accordingly, solid SMEDDS (S-SMEDDS) prepared by solidification of liquid/semisolid self-micron emulsifying (SME) ingredients into powders have gained popularity. This article provides an overview of the recent advancements in S-SMEDDS such as methodology, techniques and future research directions.


Author(s):  
J M Shah ◽  
N.H Shah ◽  
Hadiya P D

Pharmaceutical technology has developed various newer modes of novel drug delivery aspects. Modifications in the previously existing drug delivery methods have led to various newly innovated technologies serving as a safe and effective means of improvement over the existing ones. Novasome technology is one of the new innovations of liposomes which have solved many of the problems related to liposomal drug delivery system. It offers a seven bilayer membrane which has the ability to incorporate both water soluble and insoluble drugs. It has an excellent entrapment efficiency which provides better medication. Formulation of novasomes is achieved in a high shear device. Due to its numerous advantages, novasomes have been used extensively in various fields like cosmetics, chemical, personal care, foods, pharmaceuticals and agrochemicals.


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