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No description available.

Coacervation is a mild process for developing protein NPs. Bovine serum albumin (BSA) NPs formed via this technique were stabilized using poly-L-Lysine (PLL); short interfering ribonucleic acid (siRNA) was used as a model drug for encapsulation. Specific and non-specific degradation of these coated and uncoated BSA NPs were carried using matrix metalloproteinase-2 (MMP-2) and trypsin, respectively. The particles were characterized with atomic force microscopy, zeta-potential, and photon correlation spectroscopy measurements. There was a significant increase in the zeta potential of BSA NPs upon coating. Trypsin digested the uncoated and coated BSA NPs and resulted in higher BSA release from the particles. However, MMP-2 treatment did not result in higher release of BSA from coated NPs despite the cleavability of coated polymer by MMP-2. This study described a method for obtaining BSA NPs in a controllable size range. Such particles showed degradability in the presence of trypsin and could be promising for targeted drug delivery applications. / Chemical Engineering

Low temperature-processed, porous sol-gel glasses represent a new class of materials for the immobilisation of biomolecules. If used to entrap biological recognition elements, these transparent and chemically inert glasses offer a new approach in the development of optical biosensors.

One-dimensional nanostructures have offered unique advantages in many fields. Protein based nanotubes, in particular, are desirable for biomedical applications due to their ease of functionlization and intrinsic biocompatibility. Template-assisted methods are widely used to fabricate cylindrical nanostructures like carbon nanotubes, metal nanowires, polymer nanorods, etc. In the fabrication of protein nanostructures, the layer by layer (LbL) technique has long been applied to deposit protein multilayers on planar and spherical substrates. The success in each area led to the conclusion that the combination of these two techniques will potentially bring us the capability of fabricating protein nanotubes in a more controllable fashion. In this work, protein nanotubes have been successfully deposited inside nanoscopic pores by sequential filtration of bovine serum albumin (BSA) solution at pH 3.8 and pH 7.0 through the channels in the anodic aluminum oxide (AAO) template. The morphologies of the obtained nanostructures have been examined using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Also, a simple analysis from UV/Vis spectroscopy has shown that the solutions used in our experiment will not significantly damage the bioactivity of BSA. Our future work will focus on strengthening the mechanical stability of the protein nanotubes and controlling their morphology more precisely.

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Hypercholesterolemia is a major risk factor for cardiovascular disease (CVD). Interestingly, the consumption of dairy products, namely milk, has been shown to lower cholesterol. The mechanism of action surrounding this observation has been attributed to the protein fraction of milk. While there have been many studies evaluating the effects of dietary protein sources on cholesterol concentrations, few studies have evaluated specific animal protein components and no human clinical studies regarding the effects of animal plasma protein fractions on cholesterol metabolism have been conducted. This study examined the effect of an oral serum bovine immunoglobulin protein fraction (bIg) derived from US Department of Agriculture approved beef (aged < 30 months) on lipid indices in hypercholesterolemic humans. Participants included men and women (aged 25 – 70 years) with mild hypercholesterolemia (5.44-6.99 mmol/L) who were not receiving cholesterol-lowering medication. Treatment consisted of the randomized, double blind, parallel group, placebo-controlled administration of 5 grams (g) bIg daily for 6 weeks (W) in 52 participants (n = 26 each in treatment and control groups). Mean (± SD) baseline treatment and placebo total cholesterol (TC) was 6.33 ± 0.1 mmol/L and 6.16 ± 0.1 mmol/L respectively. A repeated-measures multivariate analysis of covariance (MANCOVA) covaried for change in total energy and alcohol intake, and a Tukey posthoc examination of the data showed that the bIg-treated group demonstrated a significant reduction in TC at 3-week (W) (5.98 ± 0.5 mmol/L; P < 0.05) and 6-week (W) (5.97 ± 0.7 mmol/L; P > 0.05) intervals compared to baseline. The 6W concentration was significantly lower than the placebo group (P < 0.05). Additionally, study findings displayed no significant changes in the placebo group or in any other lipid indexes or markers associated with hepatorenal or cardiovascular health. Consumption of bIg appears to lower major lipid indexes associated with CVD.

Investigations detailed in this thesis constitue a part of continuing programme of research work undertaken in this laboratory on vitamin binding proteins. Avidin from the chicken egg white, streptavidin &om the bacterium Streptromyces avidin and biotin binding proteins (BBP-I and BBP-11) from chicken egg yolk constitute a family of proteins that bind the vitamin biotin with extremely high affinities. The yolk BBPs are involved in the deposition of the vitamin in the developing oocyte in chicks whereas an antimicrobial function has been attributkl to avidin.. The fact that all these proteins bind the vitamin in the same manner, unlike biotin-dependent enzymes, indicates that the structural features involved in ligand binding could be similar, if not identical in these proteins. To delineate the basis of putative structural similarity among these proteins, studies were carried out using antibodies as the immunological probes. Avidin, a homotetremer glycoprotein, with a subunit Mr of 17,000 has been purified to homogeneity from chicken egg white using a novel procedure involving ammonium sulphate fractionation, ethanol precipitation and S-Sepharose column chromatography. Despite their lesser abundance in chicken egg yolk associated with a large amount of interfering lipids during the purification, both BBP-I (monomer and shown to be precursor for BBP-11) and BBP-I1 (tetramer) have been purified to homogeneity by employing a common method using butanol extraction to remove the lipids, DEAE-Sephacel column chromatography, biotin-AH-Sepharose affinity chromatography and fast performance liquid chrometography (FPLC) system. The purity of all these proteins was confirmed by SDS-PAGE analysis.

Background: Silica is the common name for silicon dioxide (SiO2) materials and exists in both crystalline and amorphous forms. While crystalline silica is known for its severe health effects, amorphous silica has been considered safe and applied in many areas. However, some recent studies have showed evidence of their toxicity, raising concerns about its use as nanomaterial for biomedical applications. When nanomaterials enter the body, they are enveloped in biological fluids rich in biomolecules, which compete for binding to the nanomaterial. Such effect could alter their surface chemistry and therefore affect their bio-distribution and interaction with cells. Aim and objectives: As part of the EU-funded NANODRUG network programme, the aim of this project was the in vitro toxicity assessment of commercially-sourced fumed and colloidal amorphous silica particles in relation to their physico-chemical properties and potential application as carriers for drug delivery. The objectives were 1) characterization of silica particles hydrodynamic (Hd) size and dispersity in different cell culture media; 2) in vitro toxicological assessment of silica particles in human skin cells; 3) delineation of toxicity mechanisms in relation to their size; 4) assessment of the influence of Foetal Bovine Serum (FBS) on particle Hd size and toxicity; and 5) contributing to the overall objective of the NANODRUG programme - development of safe nanodrugs for skin application - through collaborations with different partners.

Nanoparticles are currently used in a wide range of applications including industrially processes, consumer products, and as drug delivery vehicles. The potential toxicity of these nanoparticles in living organisms is concerning due to their ever-expanding applications and accumulation in the environment. The effects of properties of the human body on the potential harmful nature of these nanoparticles must be understood in order to ensure safety in workplaces and at-home products. In this thesis, the interactions between nanoparticles and the most abundant blood protein, serum albumin, were investigated. The effects of changing the aqueous environment was investigated over a range of different pH values and with different ionic salts dissolved in water. The effects of changing the nanoparticle substrate were investigated to determine if different nanoparticles affect proteins differently. Finally, the effects of changing the concentration of nanoparticles and the presence of protein were investigated in a model lung cell line in vitro. The studies over different pH values revealed that serum albumin was able to adsorb to the silica nanoparticle surface, and retained its secondary structure both as a function of pH and adsorption in a 2-hour time frame. However, adsorption was greater on the titanium dioxide nanoparticle surface and the protein lost secondary structure at acidic pH (pH 2.0). Studies with different ionic salts revealed a possible correlation between BSA adsorption and nanoparticle aggregation in that the attractive interactions between nanoparticles were least when the least amount of protein was adsorbed. To the nanoparticle surface. In vitro studies with A549 human adenocarcinoma lung cells were inconclusive in determining the potential toxicity of these nanoparticles, but preliminary results suggested that the addition of protein to the system decreased toxicity compared with nanoparticles alone. This research aims to inform the field of nanotechnology to investigate the safety and efficacy of nanoparticles before they reach the consumer.