Alginate nanoparticles protect ferrous from oxidation: Potential iron delivery system

A novel, efficient delivery system for iron (Fe²⁺) was developed using the alginate biopolymer. Iron loaded alginate nanoparticles were synthesized by a controlled ionic gelation method and was characterized with respect to particle size, zeta potential, morphology and encapsulation efficiency. Successful loading was confirmed with Fourier Transform Infrared spectroscopy and Thermogravimetric Analysis. Electron energy loss spectroscopy study corroborated the loading of ferrous into the alginate nanoparticles. Iron encapsulation (70%) was optimized at 0.06% Fe (w/v) leading to the formation of iron loaded alginate nanoparticles with a size range of 15-30nm and with a negative zeta potential (-38mV). The in vitro release studies showed a prolonged release profile for 96h. Release of iron was around 65-70% at pH of 6 and 7.4 whereas it was less than 20% at pH 2.The initial burst release upto 8h followed zero order kinetics at all three pH values. All the release profiles beyond 8h best fitted the Korsmeyer-Peppas model of diffusion. Non Fickian diffusion was observed at pH 6 and 7.4 while at pH 2 Fickian diffusion was observed.This research was financially supported by the HETC QIG Win 3 grant, University of Peradeniya, Peradeniya, Sri Lanka

Sustainable nanotechnology

The long-term vision of all nanotechnologists has been the fabrication of a wider range of materials and products with atomic precision. However, experts in the field have had strong differences of opinion on how rapidly this will occur. It is uncontroversial that expanding the scope of atomic precision will dramatically improve high-performance technologies of all kinds, from medicine, sensors, and displays to materials and solar power. Applying Moore’s law it is reasonable to assume all this will happen in the next 15 years or less [1]. Nanotechnology is considered to be the fifth industrial revolution. Unlike any other industrial revolution, its benefits are likely to reach a major portion of the inhabitants of the planet since many nations share a common market driven capitalist economic structure. Experts around the globe agree that we have tipped the scale of population vs. resources, probably for all time, and the balance of resources and their use is no longer in our favor [2]. , in April 2005, the Millennium Ecosystem Assessment carried out by the United Nations [1] indicated that “...the ability of ecosystems to sustain future generations can no longer be taken for granted.” In spite of the pervasive economic notion that technology will allow further production gains, accessible global oil production is estimated to have peaked. By 2020 the Middle East will control 83% of global oil supplies, and by 2070, there may be no more cost effective oil supplies available [3,4]. About 75% of the existing prescription drugs in the United States are synthetic [5], and for the remaining 25% derived from nature, they too rely on organic solvents (made from poetroleum) for their extraction and purification. From where will the medicinal agents of the future be derived as the living biomaterials are depleted and the global competition for oil increases on a daily basis? Therefore, we cannot be satisfied scientific discoveries based on non-renewable resources. It is becoming increasingly important to know the outcome of the products of a process at the end of their life time. Today, we are more aware that the innovations we come up with must not destroy the fundamentals that sustain the entire ecosystem including the humans

Effect of polyethylene glycol-intercalated organoclay on vulcanization characteristics and reinforcement of natural rubber nanocomposites

Organically modified montmorillonite (OMMT) clay was intercalated with low-molecular weight polyethylene glycol (PEG) oligomer at melt stage. The intercalation behaviour of PEG into the OMMT clay galleries and its interaction with clay platelets were characterized with X-ray diffraction (XRD) and differential scanning calorimetric techniques. A natural rubber (NR)-organoclay nanocomposite (NROCN) was prepared by melt-compounding of NR with PEG-treated organoclay (P-OMMT) and other compounding chemicals using a laboratory-scale internal mixer. XRD analysis of the nanocomposites revealed the intercalation of NR molecules into the P-OMMT clay galleries and subsequent exfoliation during the melt-compounding process. Vulcanization characteristics of the NROCN, especially processing safety and optimum curing time, have been interpreted with reference to the organic modifier of the montmorillonite clay, PEG modification and the degree of exfoliation. Solid-state mechanical properties of P-OMMT clay-filled NROCN vulcanizates have shown a significant enhancement in stiffness and strength characteristics whilst without scarifying the elasticity of the nanocomposites. Results have been explained in terms of the degree of exfoliation, dispersibility of the organoclay and strain-induced crystallization of the natural rubber.The author(s) received no financial support for the research, authorship, and/or publication of this article

Improved delivery of caffeic acid through liposomal encapsulation

Photoageing resulting from long term exposure of the skin to UV light can be minimized by scavenging the reactive photochemical intermediates with antioxidants. For effective photoprotection, the antioxidant must overcome the barrier properties of the skin and reach the target site in significant amounts. The present study aims to improve the skin penetration of caffeic acid, a very effective free radical scavenger, by encapsulating in liposomes. Caffeic acid loaded liposomes prepared using the reverse phase evaporation technique showed 70% encapsulation efficiency and size around 100 nm with zeta potential of −55 mV.In vitrodiffusion through a dialysis membrane enabled 70% release of encapsulated caffeic acid within 7 h, whereas 95% of free caffeic acid diffused within 4 h in PBS solution (pH 7.4). Liposomal caffeic acid permeation through pig skin epidermis in a Franz cell apparatus was 45 % during 7 h. In contrast, free caffeic acid was almost nonpermeable (<5%) to pig skin during this time. The DPPH assay indicated that skin penetration did not destroy the antioxidant activity of liposomal caffeic acid or free caffeic acid. In conclusion, we confirm that liposomal caffeic acid may be successfully employed as an effective photoprotective agent against UV mediated skin damage.Peer Reviewe

Chitosan-Alginate Nanoparticle System Efficiently Delivers Doxorubicin to MCF-7 Cells

A chitosan-alginate nanoparticle system encapsulating doxorubicin (DOX) was prepared by a novel ionic gelation method using alginate as the crosslinker. These nanoparticles were around 100 nm in size and more stable with higher positive zeta potential and had higher % encapsulation efficiency (95%) than DOX loaded chitosan nanoparticles (DOX Csn NP) crosslinked with sodium tripolyphosphate (STPP). FTIR spectroscopy and thermogravimetric analysis revealed successful loading of DOX. In vitro drug release showed an initial release phase followed by slow release phase with higher cumulative release obtained with DOX loaded chitosan-alginate nanoparticles (DOX Csn-Alg NP). The in vitro cytotoxicity of DOX released from the two nanoparticle systems showed a notable difference on comparison with that of free DOX on the MCF-7 cell line. The SRB assay, AO/EB staining, and fluorescence uptake study indicated that free DOX only showed dose dependent cytotoxicity, whereas both dose and time dependency were exhibited by the two sets of NPs. While both systems show sustained release of DOX, from the cell viability plots, DOX Csn-Alg NPs showed their superiority over DOX Csn NPs. The results obtained are useful for developing DOX Csn-Alg NPs as a sustained release carrier system for DOX.This research was financially supported by the HETC QIG Window 3 Grant, University of Peradeniya, Peradeniya, Sri Lanka.Peer Reviewe

Values and Diversity of Organisational Work Ethicality: Lessons Learnt from Sri Lankan Entrepreneurs

The aim of this paper is to examine values as a component of organisational work ethicality, uncovering the contextual realities of values and explore the diversity of work ethicality in the entrepreneurial context in Sri Lanka. Organisational work ethicality is explained through egoistic work ethicality, utilitarian work ethicality and deontological work ethicality. With a view to get a deeper understanding of the diversity of organisational work ethicality, a qualitative approach is adopted. Twelve entrepreneurs were selected for in-depth interviews. A thematic analysis was carried out for field notes with the support of NVivo 6 version. Findings of this study reveal that the entrepreneurial thinking and their interpretations derived different social meanings of organisational work ethicality. The final outcome shows that rather than single dominant work ethicality, a combination of work ethicalities was preferred by most of the entrepreneurs. Within this mix of ethicalities, deontological ethicality and egoistic work ethicality seem to be equally practised by the entrepreneurs. The utilitarian ethicality seems to be practised at a minimum level. As a result, the implicational value of this study lies on at the organisational level and policy making level to rethink and reestablish a mechanism to improve ethical aspects of the businesses in order to maximise social well-being while doing the right things for the society and strengthening shareholders’ protection. KeywordsBusiness Ethics, Business Practices, Deontological Work Ethicality,Egoistic Work Ethicality, Entrepreneur, Utilitarian Work Ethicality, Value

Development of photo catalytic active building materials using zno nanorods

In many urban cities, the pollutants concentration at street level is quite high because of the dispersion of the exhaust generated by a large number of vehicles is hindered by surrounding tall buildings. Control of these pollutions has become a pressing need for the well-being of society. Many methods have been developed to control these pollutions. Currently, there is an increasing interest in the control of urban pollution level by using construction materials containing photocatalytic nanomaterials, without changing original performance of the building structure. The photocatalytic materials used in the building materials for the purification process are efficient to remove the contaminants such as NOx and VOC. Many works have been concerned with the application of different types of nanomaterials in photocatalytic processes. This paper presents the systematic study on the photocatalytic activity of ZnO nanorods on construction materials. In this method, ZnO nanorods were successfully synthesized by a wet chemical route. Systematic experiments were carried out to investigate the photocatalytic activity of the samples. The prepared samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM). It has been found that the ZnO nanoflowers contain many radial nanorods with the diameter of 100 nm and the length of 1–1.5 μm and these ZnO single-crystalline nanorods with wurtzite structure grow along the [ 0 0 1] direction. The formation mechanism of ZnO nanoflowers and nanorods was initially interpreted in terms of the general theory of the crystal nucleation and crystal growth direction. ZnO with flower-like morphology exhibited improved ability on the photocatalytic degradation

Thermal Conductivity Enhancement of Al2O3 Nanofluid in Ethylene Glycol and Water Mixture

AbstractThe ability of nanofluids that exhibits enhanced thermal performance is acknowledged by researchers through studies since decades ago. However, the observation of thermal properties for nanofluids in water and ethylene glycol based is not fully explored yet. Hence, this paper presents the thermal conductivity of water and ethylene glycol (EG) based Al2O3 nanofluid. The 13 nm sized Al2O3 nanoparticles were dispersed into three different volume ratio of water: EG such as 40:60, 50:50 and 60:40 using a two-step method. The measurement of thermal conductivity was performed using KD2 Pro Thermal Properties Analyzer at working temperatures of 30 to 70 ̊C for volume concentration of 0.5 to 2.0%. The results indicate that the thermal conductivity increases with the increase of nanofluid concentration and temperature. While the percentage of ethylene glycol increase, the range of thermal conductivity decreases due to ethylene glycol properties. The measurement data of the nanofluids give maximum enhancement of thermal conductivity at condition 2.0% volume concentration, temperature of 70 ̊C and for all base fluid

Reduction of fibrillar strain-rate sensitivity in steroid-induced osteoporosis linked to changes in mineralized fibrillar nanostructure

As bone is used in a dynamic mechanical environment, understanding the structural origins of its time-dependent mechanical behaviour – and the alterations in metabolic bone disease – is of interest. However, at the scale of the mineralized fibrillar matrix (nanometre-level), the nature of the strain-rate dependent mechanics is incompletely understood. Here, we investigate the fibrillar- and mineral-deformation behaviour in a murine model of Cushing’s syndrome, used to understand steroid induced osteoporosis, using synchrotron small- and wide-angle scattering/diffraction combined with in situ tensile testing at three strain rates ranging from 10-4 to 10-1 s-1. We find that the effective fibril- and mineral-modulus and fibrillar-reorientation show no significant increase with strain-rate in osteoporotic bone, but increase significantly in normal (wild-type) bone. By applying a fibril-lamellar two-level structural model of bone matrix deformation to fit the results, we obtain indications that altered collagen-mineral interactions at the nanoscale – along with altered fibrillar orientation distributions – may be the underlying reason for this altered strain-rate sensitivity. Our results suggest that an altered strain-rate sensitivity of the bone matrix in osteoporosis may be one of the contributing factors to reduced mechanical competence in such metabolic bone disorders, and that increasing this sensitivity may improve biomechanical performance

"They all work...when you stick to them" : a qualitative investigation of dieting, weight loss, and physical exercise, in obese individuals

BackgroundTo explore the extent to which people living with obesity have attempted to lose weight, their attitudes towards dieting, physical exercise and weight loss solutions, why their weight loss attempts have failed, and their opinions about what would be most beneficial to them in their struggle with their weight.MethodQualitative study, using open-ended interviews, of 76 people living with obesity in Victoria, Australia in 2006/7. Individuals with a BMI of 30 or over were recruited using articles in local newspapers, convenience sampling, and at a later stage purposive sampling techniques to diversify the sample. Data analysis was conducted by hand using a constant, comparative method to develop and test analytical categories. Data were interpreted both within team meetings and through providing research participants the chance to comment on the study findings.ResultsWhilst participants repeatedly turned to commercial diets in their weight loss attempts, few had used, or were motivated to participate in physical activity. Friends or family members had introduced most individuals to weight loss techniques. Those who took part in interventions with members of their social network were more likely to report feeling accepted and supported. Participants blamed themselves for being unable to maintain their weight loss or \u27stick\u27 to diets. Whilst diets did not result in sustained weight loss, two thirds of participants felt that dieting was an effective way to lose weight.ConclusionIndividuals with obesity receive numerous instructions about what to do to address their weight, but very few are given appropriate long term guidance or support with which to follow through those instructions. Understanding the positive role of social networks may be particularly important in engaging individuals in physical activity. Public health approaches to obesity must engage and consult with those currently living with obesity, if patterns of social change are to occur