Nadiah Zafar

Carbon nanotubes from synthesis to in vivo biomedical applications.

Owing to their unique and interesting properties, extensive research round the globe has been carried out on carbon nanotubes and carbon nanotubes based systems to investigate their practical usefulness in biomedical applications. The results from these studies demonstrate a great promise in their use in targeted drug delivery systems, diagnostic techniques and in bio-analytical applications. Although, carbon nanotubes possess quite interesting properties, which make them potential candidates in the biomedical science, but they also have some inherent properties which arise great concern regarding their biosafety. In this comprehensive review, we have discussed different aspects of carbon nanotubes and carbon nanotube based systems related to biomedical applications. In the beginning, a short historical account of these tiny yet powerful particles is given followed by discussion regarding their types, properties, methods of synthesis, large scale production method, purification techniques and characterization aspects of carbon nanotubes. In the second part of the review, the functionalization of carbon nanotubes is reviewed in detail, which is not only important to make them biocompatible and stable in biological systems but also render them a great property of loading various biomolecules, diagnostic and therapeutic moieties resulting in diversified applications. In the final part of the review, emphasis is given on the pharmacokinetic aspects of carbon nanotubes including administration routes, absorption mechanisms, distribution and elimination of carbon nanotubes based systems. Lastly, a comprehensive account about the potential biomedical applications has been given followed by insights into the future.

Cyclodextrin containing biodegradable particles: From preparation to drug delivery applications

Cyclodextrins (CDs) offer a very broad spectrum of applications in diverse fields of drug delivery. They are a family of cyclic α-(1-4)-linked oligosaccharides of α-d-glucopyranose subunits forming a more hydrophobic central cavity and a hydrophilic outer shell. CDs bear cage like supramolecular structures, similar to calixarenes, cyclophanes and crown ethers. No covalent bonds are required to host a guest molecule in the central cavity. The aim of this review is to throw light on some of the applications and formulation techniques for the novel multifunctional CD based nanocarriers used in diverse areas of drug delivery. Furthermore, this article highlights the molecular structure, chemical, complexation properties and the use of CDs in nanosystems like liposomes, magnetic nanoparticles, biodegradable polymers, micro and nanospheres and capsules.

Elaboration of ammonio methacrylate copolymer based spongy cationic particles via double emulsion solvent evaporation process.

The aim of present work is to investigate systematic study of the preparation of biodegradable particles via double emulsion solvent evaporation technique. The used formation is based on cationic ammonium methacrylate copolymer Eudragit® RS 100, without the use of any stabilizer. The effect of process parameters like ultra turrax® stirring speed and stirring time, ultrasonication time, polymer amount, and volume of outer aqueous phases on the colloidal properties of particles was investigated. All prepared dispersions were characterized in terms of size, size distribution, and electrokinetic properties, and surface morphology was investigated.

Plant extracts: from encapsulation to application

ABSTRACT Introduction: Plants are a natural source of various products with diverse biological activities offering treatment for several diseases. Plant extract is a complex mixture of compounds, which can have antioxidant, antibiotic, antiviral, anticancer, antiparasitic, antifungal, hypoglycemic, anti-hypertensive and insecticide properties. The extraction of these extracts requires the use of organic solvents, which not only complicates the formulations but also makes it difficult to directly use the extracts for humans. To overcome these problems, recent research has been focused on developing new ways to formulate the plant extracts and delivering them safely with enhanced therapeutic efficacy. Areas covered: This review focuses on the research done in the development and use of polymeric nanoparticles for the encapsulation and administration of plant extracts. It describes in detail, the different encapsulation techniques, main physicochemical characteristics of the nanoparticles, toxicity tests and results obtained from in vivo or in vitro assays. Expert opinion: Major obstacles associated with the use of plant extracts for clinical applications include their complex composition, toxicity risks and extract instability. It is observed that encapsulation can be successfully used to decrease plant extracts toxicity, to provide targeted drug delivery and to solve stability related problems.

Colloidal particles containing labeling agents and cyclodextrins for theranostic applications

This review aims to give to the reader some new light on cyclodextrin (CD)-based theranostic agents in order to complete our recently published review dedicated to CD-particles conjugates in drug delivery systems (Zafar et al., 2014). CDs are biocompatible sugar-based macrocycles used in a wide range of biomedical applications. Here, we mainly focus on fundamental theranostic approaches combining the use of cyclodextrin molecules and colloidal particles as theranostic agents. The systems key features are discussed and a few recent pertinent applications are presented. CDs are used in order to enhance theranostic properties by providing apolar cavities for the encapsulation of hydrophobic moieties. Thus, CD molecules are used to enhance the loading capacity of particles by hosting active molecules. The relevance of CDs in enhancing the labeling properties of particles and the preparation of controlled drug release particles is also highlighted.

Elaboration of sponge-like biodegradable cationic particles via double-emulsion solvent evaporation

ABSTRACT Researchers work on different optimization methods to come up with preparation methods, which show the desired or targeted outcomes. Moreover, nowadays, research is more focused on developing formulations which contain biodegradable polymers. The objective of the present systematic study was to achieve the abovementioned goals by using a cationic ammonio methacrylate copolymer (Eudragit® RS100). A Double-emulsion solvent evaporation technique was used. This methodology was chosen because the particles formed by this method allow encapsulation of both hydrophilic and hydrophobic active molecules. It also has applications in diverse fields such as drug delivery, food, cosmetics, and pharmaceutical industries. The aim of this research work was to investigate the influence of various process control parameters, such as stabilizer chemical nature and amount, ultra Turrax® stirring speed and time, the morphology, size, and size distribution of the final dispersions. Then, the prepared particles were characterized using a Scanning Electron Microscope (SEM) and a Laser Diffraction Particle Size Analyzer. This study helped us to know which parameters have a drastic effect on the colloidal properties of the particles. GRAPHICAL ABSTRACT