Development of Biodegradable Polyphosphazene- Nanohydroxyapatite Composite Nanofibers Via Electrospinning

2004 ◽  
Vol 845 ◽  
Author(s):  
Subhabrata Bhattacharyya ◽  
Lakshmi S. Nair ◽  
Anurima Singh ◽  
Nick R. Krogman ◽  
Jared Bender ◽  
...  

ABSTRACTBiodegradable polymeric nanofibers are of great interest as scaffolds for tissue engineering and drug delivery due to their extremely high surface area, high aspect ratio and similarity in structure to the extracellular matrix (ECM). Polyphosphazenes due to their synthetic flexibility, wide range of physico-chemical properties, non-toxic and neutral degradation products and excellent biocompatibility are suitable candidates for biomedical applications. The objective of the present study was to develop and evaluate composite nanofibers of a biodegradable polyphosphazene, poly[bis(ethyl alanato)phosphazene] (PNEA) and nanocrystals of hydroxyapatite (nHAp) via electrospinning. A suspension of nHAp in dimethyl formamide (DMF) sonicated with PNEA solution in tetrahydrofuran (THF) was used to develop composite nanofiber matrices via electrospinning at ambient conditions. In the present study the theoretical loading of nHAp was varied from 50%-90% (w/w) to PNEA. The nHAp content (actual loading of nHAp) of the composite nanofibers was determined by gravimetric estimation. The composite nanofibers were characterized by transmission electron microscopy (TEM), gravimetry and energy dispersive X-ray mapping. This study demonstrated the feasibility of developing novel composite nanofibers of biodegradable polyphosphazenes with more than 50% (w/w) loading of nHAp on and within the nanofibers.

Author(s):  
PARDEEP KUMAR ◽  
AJINKYA GIRISH NENE ◽  
SANDEEP PUNIA ◽  
MANOJ KUMAR ◽  
ZAHOOR ABBAS ◽  
...  

Objective: The present study was done to see the effect of biologically synthesized CuO-NPs (Copperoxide nanoparticles) on the growth of bacterial strains. Methods: Physico-chemical characterization of CuO-NPs was done by UV-Vis-spectrophotometer, XRD, FE-SEM, and EDS. The disc plate diffusion assay was used to evaluate the anti-bacterial effect of CuNPs. Results: This study has shown a promising anti-bacterial activity of biosynthesized CuO-NPs at different concentrations ranging from 10 to 100 µg/ml against Escherichia coli and Staphylococcus aureus bacteria. Conclusion: Nanoparticles (NPs) are small size particles between range 1 to 100 nm which expand their physical and chemical properties due to high surface area. The present study reveals that there may be possible utilization of biosynthesized CuO NPs for the treatment of bacterial infectious disease in near future.


2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Bianca Caratão ◽  
Edgar Carneiro ◽  
Pedro Sá ◽  
Bernardo Almeida ◽  
Sandra Carvalho

Titanium oxide filled polyvinylpyrrolidone (PVP) composite nanofibers have been prepared via a simple electrospinning technique. The combination of good TiO2properties with its high surface area leads these nanofibers into having a vast applicability such as cosmetics, scaffolds for tissue engineering, catalytic devices, sensors, solar cells, and optoelectronic devices. The structural and chemical properties of the prepared samples have been studied. The presence of the TiO2phase on the nanofibers was confirmed. An anatase to rutile transformation was observed at 600°C. Regarding the thermogravimetric and differential thermal analysis (TGA/DTA), the TIP decomposition and the PVP evaporation at 225°C were verified.


2021 ◽  
Vol 3 ◽  
Author(s):  
Prabhpreet Kaur ◽  
Neha Sharma ◽  
Meghana Munagala ◽  
Rangam Rajkhowa ◽  
Ben Aallardyce ◽  
...  

The growing environmental concerns due to the excessive use of non-renewable petroleum based products have raised interest for the sustainable synthesis of bio-based value added products and chemicals. Recently, nanocellulose has attracted wide attention because of its unique properties such as high surface area, tunable surface chemistry, excellent mechanical strength, biodegradability and renewable nature. It serves wide range of applications in paper making, biosensor, hydrogel and aerogel synthesis, water purification, biomedical industry and food industry. Variations in selection of source, processing technique and subsequent chemical modifications influence the size, morphology, and other characteristics of nanocellulose and ultimately their area of application. The current review is focused on extraction/synthesis of nanocellulose from different sources such as bacteria and lignocellulosic biomass, by using various production techniques ranging from traditional harsh chemicals to green methods. Further, the challenges in nanocellulose production, physio-chemical properties and applications are discussed with future opportunities. Finally, the sustainability of nanocellulose product as well as processes is reviewed by taking a systems view. The impact of chemicals, energy use, and waste generated can often negate the benefit of a bio-based product. These issues are evaluated and future research needs are identified.


Author(s):  
Frances M. Ross ◽  
Peter C. Searson

Porous semiconductors represent a relatively new class of materials formed by the selective etching of a single or polycrystalline substrate. Although porous silicon has received considerable attention due to its novel optical properties1, porous layers can be formed in other semiconductors such as GaAs and GaP. These materials are characterised by very high surface area and by electrical, optical and chemical properties that may differ considerably from bulk. The properties depend on the pore morphology, which can be controlled by adjusting the processing conditions and the dopant concentration. A number of novel structures can be fabricated using selective etching. For example, self-supporting membranes can be made by growing pores through a wafer, films with modulated pore structure can be fabricated by varying the applied potential during growth, composite structures can be prepared by depositing a second phase into the pores and silicon-on-insulator structures can be formed by oxidising a buried porous layer. In all these applications the ability to grow nanostructures controllably is critical.


2021 ◽  
Author(s):  
Ayat Nuri ◽  
Abolfazl Bezaatpour ◽  
Mandana Amiri ◽  
Nemanja Vucetic ◽  
Jyri-Pekka Mikkola ◽  
...  

AbstractMesoporous SBA-15 silicate with a high surface area was prepared by a hydrothermal method, successively modified by organic melamine ligands and then used for deposition of Pd nanoparticles onto it. The synthesized materials were characterized with infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), nitrogen physisorption, scanning electron microscopy (SEM) coupled with energy dispersive X-ray analysis (EDX), transmission electron microscopy (TEM), nuclear magnetic resonance (NMR) and inductively coupled plasma (ICP-OES). The catalyst was effectively used in the Mizoroki–Heck coupling reaction of various reactants in the presence of an organic base giving the desired products in a short reaction time and with small catalysts loadings. The reaction parameters such as the base type, amounts of catalyst, solvents, and the temperature were optimized. The catalyst was easily recovered and reused at least seven times without significant activity losses. Graphic Abstract


2013 ◽  
Vol 798-799 ◽  
pp. 1123-1127
Author(s):  
Hua Lei Zhou ◽  
Qiong Qiong Zhu ◽  
Dong Hua Huang

The activated carbon with high surface area was prepared by KOH activation from anthracite and used as adsorbent for removal of Cr (VI) from aqueous solution. The pore structure and surface properties were characterized by N2 adsorption at 77K, transmission electron microscope (TEM) and Fourier transform infrared spectroscopy ( FTIR). Effect of pH and isotherms at different temperature were investigated. Results show that the prepared carbon is a microporous-and mesoporous-adsorbent with developed pore structure and abundant surface oxygen-containing groups. PH value of the solution plays key function on the adsorption. The chemical adsorption dominates the adsorption process. The activated carbon exhibits much higher Cr adsorption capacity than the commercial activated carbon at initial pH of ~3. The equilibrium adsorption data are fitted by both Freundlich model and Langmuir model well.


2013 ◽  
Vol 284-287 ◽  
pp. 230-234
Author(s):  
Yu Jen Chou ◽  
Chi Jen Shih ◽  
Shao Ju Shih

Recent years mesoporous bioactive glasses (MBGs) have become important biomaterials because of their high surface area and the superior bioactivity. Various studies have reported that when MBGs implanted in a human body, hydroxyl apatite layers, constituting the main inorganic components of human bones, will form on the MBG surfaces to increase the bioactivity. Therefore, MBGs have been widely applied in the fields of tissue regeneration and drug delivery. The sol-gel process has replaced the conventional glasses process for MBG synthesis because of the advantages of low contamination, chemical flexibility and lower calcination temperature. In the sol-gel process, several types of surfactants were mixed with MBG precursor solutions to generate micelle structures. Afterwards, these micelles decompose to form porous structures after calcination. Although calcination is significant for contamination, crystalline and surface area in MBG, to the best of the authors’ knowledge, only few systematic studies related to calcination were reported. This study correlated the calcination parameters and the microstructure of MBGs. Microstructure evaluation was characterized by transmission electron microscopy and nitrogen adsorption/desorption. The experimental results show that the surface area and the pore size of MBGs decreased with the increasing of the calcination temperature, and decreased dramatically at 800°C due to the formation of crystalline phases.


2021 ◽  
Vol 18 ◽  
Author(s):  
Raja Murugesan ◽  
Sureshkumar Raman

: At present treatment methods for cancer are limited, partially due to the solubility, poor cellular distribution of drug molecules and, the incapability of drugs to annoy the cellular barriers. Carbon nanotubes (CNTs) generally have excellent physio-chemical properties, which include high-level penetration into the cell membrane, high surface area and high capacity of drug loading by in circulating modification with bio-molecules, project them as an appropriate candidate to diagnose and deliver drugs to prostate cancer (PCa). Additionally, the chemically modified CNTs which have excellent 'Biosensing' properties therefore makes it easy for detecting PCa without fluorescent agent and thus targets the particular site of PCa and also, Drug delivery can accomplish a high efficacy, enhanced permeability with less toxic effects. While CNTs have been mainly engaged in cancer treatment, a few studies are focussed on the diagnosis and treatment of PCa. Here, we detailly reviewed the current progress of the CNTs based diagnosis and targeted drug delivery system for managing and curing PCa.


Author(s):  
Guru Venkatesan ◽  
Andy Sarles

Droplet-based biomolecular arrays form the basis for a new class of bioinspired material system, whereby decreasing the sizes of the droplets and increasing the number of droplets can lead to higher functional density for the array. In this paper, we report on a non-microfluidic approach to form and connect nanoliter-to-femtoliter, lipid-coated aqueous droplets in oil to form micro-droplet interface bilayers (μDIBs). Two different modes of operation are reported for dispensing a wide range of droplet sizes (2–200μm radius). Due to the high surface-area-to-volume ratios of microdroplets at these length scales, droplet shrinking is prominent, which affects the stability and lifetime of the bilayer. To better quantify these effects, we measure the shrinkage rates for 8 different water droplet/oil compositions and study the effect of lipid placement and lipid type on morphological changes to μDIBs.


2021 ◽  
Author(s):  
Nuray Kizildag

Ceramic materials are well known for their hardness, inertness, superior mechanical and thermal properties, resistance against chemical erosion and corrosion. Ceramic nanofibers were first manufactured through a combination of electrospinning with sol–gel method in 2002. The electrospun ceramic nanofibers display unprecedented properties such as high surface area, length, thermo-mechanical properties, and hierarchically porous structure which make them candidates for a wide range of applications such as tissue engineering, sensors, water remediation, energy storage, electromagnetic shielding, thermal insulation materials, etc. This chapter focuses on the most recent advances in the applications of ceramic nanofibers.


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