Developing a drug delivery vehicle that can control the release kinetics of a therapeutic drug on demand has great potential to improve health by allowing health care professionals to maintain the drug concentration in its therapeutic window and increase the efficiency at which treatment is administered. On-demand release can be triggered by a range of stimuli including magnetic, radiation, and ultrasound activation. Of the three, ultrasound is the only one indiscriminate of the chemical properties of the material and is the most widely available clinically, which makes it versatile and applicable for many systems. However, existing strategies that use ultrasound as a release stimulus either pop the microcapsules altogether (enabling no subsequent effective control over the kinetics of drug release) or require continuous ultrasonic administration (typically impractical in a clinical setting), both of which are suboptimal. Overcoming at least of these shortcomings would vastly improve on the technology. In this thesis, microcapsules with a complex shell were fabricated using a modified electrohydrodynamic approach named immersion coaxial electrospraying, which allowed for an increased polymer loading in the shell and improved manipulation of microcapsule size. The complex shell structure of the microcapsules incorporated silica microparticles that acted as corks plugging pores between the inside and outside of the microcapsule. The modified microcapsules were shown to release their payload in the presence of a focused ultrasound signal, while uncorked microcapsules do not release. Release kinetics were shown to be adjustable based on the number of corks initially present in the shell of the microcapsule material. Altogether, the cork-shell microcapsules fabricated in this thesis show promise as a tunable on-demand drug delivery vehicle that is able to better control release compared to conventional ultrasound triggered microcapsules. / Thesis / Master of Applied Science (MASc) / This thesis focuses on the fabrication of complex microcapsules that can be deliver therapeutic drugs on-demand using ultrasound waves. These microcapsules are composed of a water-based core and a biologically inert shell into which particles are embedded. Upon the application of ultrasound, these embedded particles (like corks on a bottle) are popped out to release the “corks” from the shell, creating pores from which the drug in the microcapsule core can be released. In the absence of ultrasound signals, the microcapsules do not release any of their contents, making these effective for “on-demand” release. These microcapsules are made using a modified process based on electrospraying which allows very precise control over the microcapsules’ physical properties, incorporating a key modification that overcomes an inherent issue with the general technique. These microcapsules also improve on currently used ultrasound triggered drug delivery systems by requiring shorter periods of ultrasound and/or enabling better control over the dynamics of drug release following the ultrasound pulse.

Telomerase, discovered in 1985, is considered a near-universal marker of malignancy and therefore has a potential use in cancer therapeutics and diagnostics. In this study, I used several approaches to gain a better understanding of telomerase and its potential applications in the canine context, for both cancer therapeutics and diagnosis. Having already developed an effective siRNA viral vector in vitro, the challenge still remained to deliver it efficiently in vivo. Thus, I initially investigated two possible approaches for in vivo delivery. First, I investigated a cell-based system for direct delivery to the tumours. Specifically I optimised a system for efficient gene-transfer to endothelial cells using a green fluorescent protein plasmid vector, and monitored systemic delivery by ex vivo imaging of dye-labelled cells in a canine xenograft tumour mouse model. In parallel, in vitro I investigated the gene transfer mediated by a novel dendrimer vector that can form nanoparticles with DNA and accumulate in tumour sites in vivo after i.v. administration. In order to utilize these delivery systems, I developed a DNA plasmid-based siRNA vector and tested its efficacy on canine tumour cells. To investigate telomerase as a cancer biomarker, I conducted a study that aimed to detect circulating telomerase reverse transcriptase (TERT) mRNA in serum taken from canine cancer patients. For this I developed several systems for effective RNA isolation from serum and used both conventional and quantitative PCR assays to detect TERT expression. Although for the first time I can confirm the existence of mRNA in serum of canine cancer patients, in this clinical study, I could only detect telomerase transcripts in a very small proportion of canine cancer patients. In a final pilot study to investigate anti-ageing technologies, I looked at the potential for drug-dependant telomerase induction rather than inhibition. For this I investigated the ability of three candidate drugs to induce TERT mRNA activation in canine embryonic fibroblasts. In this study, telomerase induction was measured using the quantitative PCR method that I had developed for serum detection. In summary, I have demonstrated that a cell-based delivery vehicle has a potential application in cancer therapy, but that more development is required before it can be applied clinically. I have also reported here that PPIG3 dendrimer-based gene transfer in vitro is low in canine cancer cells and thus require more optimisation and development before it can be utilised as an efficient systemic delivery vehicle. For the siRNA experiment, unfortunately, I did not observe any telomerase genesilencing in canine cancer cells using the plasmid-based siRNA expression vector, and therefore the gene sequence of cTR that we were targeting as well as the siRNA plasmid-vector that we used needs further validation in canine cells. I also suggest that TERT mRNA may not be a good serum biomarker for canine cancer diagnostics as I did not find TERT transcript in most of our serum samples from canine cancer patients, although circulating mRNA of a housekeeping gene was detected. Finally, in a pilot study, I have demonstrated that telomerase can be induced in normal canine somatic cells using small molecules. However, the long-term effects of telomerase induction on ageing must be determined in future studies.

The skin, by weight, is the largest organ of the body. Human skin serves to provide several important functions that may be classified. in a general context, as protective, maintaining homeostasis and sensing. The outermost layer of the skin, the stratum corneum, has an essential role as a barrier against the transport of water and of chemical and biological agents. In this study acyclovir (ACV), an antiviral used for treating the varicella zoster virus, was used. It is sensible to say that a hydrophilic drug like acyclovir needs a delivery vehicle or penetration enhancer to permeate the skin with more ease. In an attempt to enhance the permeation of acyclovir, it was formulated in a delivery vehicle with the same formulation as for a micro-emulsion. Increasing percentages of the surfactant, Brij 97, were incorporated in the formulation to determine which of the four formulations is indeed a micro-emulsion. A gelating agent. carrageenan, was used to make the emulsion transdermally more applicable; the influence of this component on the transdermal delivery of acyclovir was also determined. Therefore the aim of this study was to determine: -The effect of a drug delivery vehicle on the transdermal delivery of acyclovir; -The specific formulation of a micro-emulsion and -The influence of a gelating agent on the transdermal delivery of acyclovir. Diffusion studies were performed in vertically mounted glass Franz diffusion cells. The epidermis of female abdominal skin, obtained after abdomeoplasty, was heat separated from the dermis. One millilitre of emulsion (0.1%: 1mg/ml ACV) was added to the skin sample in the donor side of the diffusion cell. The control solution had an equivalent amount of active in water and was added to the donor compartment in a separate experiment. The receptor phase was PBS (phosphate buffered solution). The entire receptor phase of the cells was removed every second hour and was replaced with fresh receptor phase at 37°C. The amount of acyclovir in the receptor phase was determined by HPLC analysis. The cumulative amounts of the active that permeated the skin over the 24 hour period were plotted with the slope of the graphs representing the flux in ng/cm²/h. The average flux values of the experimental cells and control cells were compared. Results of the diffusion studies without carrageenan showed that increasing the concentration of the surfactant increased the diffusion of acyclovir. Permeation studies with carrageenan had a totally different outcome. The enhancement ratio of the experimental cells was much lower than that of the control cells. However the experimental cells showed a small increase as the concentration of the surfactant increased. From VanKel dissolution studies it could be seen that release of acyclovir from the emulsion was not a problem and that the active was available for absorption. Confocal studies were done to determine whether there were any vesicles in the emulsions. Vesicles were expected in the 25% Brij 97 emulsion because it was the same formulation as a micro-emulsion, but vesicles could only be found in the 4% and 8% Brij 97 emulsion. A previous study with acyclovir and three different delivery vehicles gave enhancement ratios between 0.32 to 2.92. Values obtained in this study of the 4% and 8% Brij 97 emulsion without carrageenan were more or less the same but the 15% and 25% Brij 97 emulsion had a much higher enhancement ratio. For the emulsions with carrageenan not one exceeded an enhancement ratio of 0.57. More studies still have to be done on micro-emulsions to determine which specific concentration of surfactant forms a micro-emulsion. The active itself and its physicochemical properties also play an important role in the diffusion studies with the specific delivery vehicle and further research has to be done with different model drugs. / Thesis (M.Sc. (Pharmaceutics))--North-West University, Potchefstroom Campus, 2006.

Polymeric biomaterials have become ubiquitous in modern medical devices. ‘Smart’ materials, materials that respond to external stimuli, have been of particular interest for biomedical applications such as drug delivery. Poly(n-isopropylacrylamide) (pNIPAAm) is the best studied thermally responsive, biocompatible, ‘smart’ polymer and has been integrated into many potential drug delivery devices; however, the architectural design of the polymer in these devices is often overlooked. My research focus was the exploration of pNIPAAm architecture for biological applications. Two new biomaterials were synthesized as a result. Architectural modification of linear pNIPAAm was used to synthesize a well-defined homopolymer pNIPAAm with a sharp transition slightly above normal body temperature under isotonic conditions. This polymer required a combination of polymerization and control techniques including controlled radical polymerization, hydrogen bond induced tacticity, and end-group manipulation. The synthesis of this polymer opened up a variety of biomedical possibilities, one of which is the use of these polymers in a novel hydrogel system. Through the use of the controlled linear pNIPAAm synthesized through chain architectural modification, hydrogels with physiological transition temperatures were also synthesized. These hydrogels showed greater shrinking properties than traditional hydrogels synthesized in the same manner and showed physiological mechanical properties. Highly branched pNIPAAm was also optimized for biological applications. In this case, the branching reduced the efficacy of end-groups in transition temperature modification but increased the efficacy of certain copolymers. The resulting biomaterial was incorporated into a nanoparticle drug delivery system. By combining gold nanoparticles with highly branched pNIPAAm, which was designed to entrap small molecule drugs, a hybrid system was synthesized where heating of the nanoparticle through surface plasmon resonance can trigger drug release from the pNIPAAm. This system proved to be easy to synthesize, effective in loading, and controlled in release. As shown from the applications, architectural control of pNIPAAm can open up new possibilities with this polymer for biomedical applications. Small structural changes can lead to significant changes in the bulk properties of the polymer and should be considered in future pNIPAAm based medical devices.

The skin, by weight, is the largest organ of the body. Human skin serves to provide several important functions that may be classified. in a general context, as protective, maintaining homeostasis and sensing. The outermost layer of the skin, the stratum corneum, has an essential role as a barrier against the transport of water and of chemical and biological agents. In this study acyclovir (ACV), an antiviral used for treating the varicella zoster virus, was used. It is sensible to say that a hydrophilic drug like acyclovir needs a delivery vehicle or penetration enhancer to permeate the skin with more ease. In an attempt to enhance the permeation of acyclovir, it was formulated in a delivery vehicle with the same formulation as for a micro-emulsion. Increasing percentages of the surfactant, Brij 97, were incorporated in the formulation to determine which of the four formulations is indeed a micro-emulsion. A gelating agent. carrageenan, was used to make the emulsion transdermally more applicable; the influence of this component on the transdermal delivery of acyclovir was also determined. Therefore the aim of this study was to determine: -The effect of a drug delivery vehicle on the transdermal delivery of acyclovir; -The specific formulation of a micro-emulsion and -The influence of a gelating agent on the transdermal delivery of acyclovir. Diffusion studies were performed in vertically mounted glass Franz diffusion cells. The epidermis of female abdominal skin, obtained after abdomeoplasty, was heat separated from the dermis. One millilitre of emulsion (0.1%: 1mg/ml ACV) was added to the skin sample in the donor side of the diffusion cell. The control solution had an equivalent amount of active in water and was added to the donor compartment in a separate experiment. The receptor phase was PBS (phosphate buffered solution). The entire receptor phase of the cells was removed every second hour and was replaced with fresh receptor phase at 37°C. The amount of acyclovir in the receptor phase was determined by HPLC analysis. The cumulative amounts of the active that permeated the skin over the 24 hour period were plotted with the slope of the graphs representing the flux in ng/cm²/h. The average flux values of the experimental cells and control cells were compared. Results of the diffusion studies without carrageenan showed that increasing the concentration of the surfactant increased the diffusion of acyclovir. Permeation studies with carrageenan had a totally different outcome. The enhancement ratio of the experimental cells was much lower than that of the control cells. However the experimental cells showed a small increase as the concentration of the surfactant increased. From VanKel dissolution studies it could be seen that release of acyclovir from the emulsion was not a problem and that the active was available for absorption. Confocal studies were done to determine whether there were any vesicles in the emulsions. Vesicles were expected in the 25% Brij 97 emulsion because it was the same formulation as a micro-emulsion, but vesicles could only be found in the 4% and 8% Brij 97 emulsion. A previous study with acyclovir and three different delivery vehicles gave enhancement ratios between 0.32 to 2.92. Values obtained in this study of the 4% and 8% Brij 97 emulsion without carrageenan were more or less the same but the 15% and 25% Brij 97 emulsion had a much higher enhancement ratio. For the emulsions with carrageenan not one exceeded an enhancement ratio of 0.57. More studies still have to be done on micro-emulsions to determine which specific concentration of surfactant forms a micro-emulsion. The active itself and its physicochemical properties also play an important role in the diffusion studies with the specific delivery vehicle and further research has to be done with different model drugs. / Thesis (M.Sc. (Pharmaceutics))--North-West University, Potchefstroom Campus, 2006.

The following work concerns the study of the evolutionary algorithm, which optimizes freight transport planning. The demand for freight transport is constantly increasing nowadays and with creating, implementing and using proper route planning we are able to significantly reduce transportation costs. However, it is preferably to implement it in companies with large numbers of served customers and with a sufficiently large fleet of vehicles.   The study starts by defining what fright transport planning problem is and by characterizing its existing specifications and variants. My work proceeds to give a background of the possible solutions to the multifaceted aspects of the problem. The specific subproblem I choose to focus on is the Vehicle routing problem with Pickup and Delivery for which I apply the optimization solution. In the main body of my thesis, I will elaborate on the chosen optimization solution which encompasses the genetic algorithm and evolutionary strategy. The aim of the study is to measure the suitability of the algorithms and techniques used, for which reason the final part of my work will deal with the analysis and evaluation of the experiments.

There is a need for a minimally invasive delivery method to enable cell therapies to combat peripheral artery occlusive disease (PAOD) in end stage patients. Myoblasts show promise as a cell mediated therapy but warrant an improved delivery method to increase cell retention in the region of interest because of their adherent nature, relative to previously used BM-MNC’s that are non-adherent. Contemporary issues with achieving successful cell therapies of vasculature can be mainly characterized by the lack of clinical translation from promising animal studies and absence of cell delivery scaffolding. Naturally, polymers have been widely experimented with as grafts to both culture and implant cells into tissue with recognizable success due to their analogous physical properties, such as stiffness, hydrophilicity, & surface energy, that mimic tissue conditions. Polymers having similar mechanical properties to anatomical structures are conducive to cell integration & retention, making polymers an effective biomaterial choice as a cell delivery vehicle. This thesis will evaluate the application of N-isopropylacrylamide (NIPAM) based copolymers as a biomaterial scaffold for myoblast delivery, as it is one of the most widely used biocompatible polymers with thermoreversible properties that is non-toxic and has manipulatable mechanical properties. We hypothesized that fluctuations in polymer construct stiffness, surface energy, and water retention affect myoblast proliferation & viability within the cell delivery vehicle. After measuring the physical properties and cellular proliferation in for each polymer composition, the goal of this thesis was to establish a statistical model to characterize the effect of polymer material properties on myoblast behavior and create a predictive model to optimize further iterations of NIPAM-based copolymers for cell delivery.

Split delivery vehicle rating problem is one of the most studied combinatorial optimization problems in operations research. According to the mathematical difficultness, there should be many problems to find the optimal solution. Therefore, there are many exact algorithms and heuristics, which tries to find the best solution in the short period of time. The theoretical part of this thesis describes the basic facts of the split delivery vehicle routing problem and its heuristics. The practical part focuses on the practical usage of the split delivery vehicle routing problem. The main goals of this thesis are the practical usage of this vehicle routing problem and assistance in strategic decision establishing of the secondary store.

La gestion des stocks et la maîtrise de la distribution sont les deux activités importantes dans le management de la chaîne logistique. L’optimisation simultanée de ces deux activités est connue sous l’intitulé du problème de gestion de stock et de tournée de livraison (Inventory Routing Problem, IRP). L’IRP traditionnelle est confronté aux différents problèmes, causé principalement par le manque d'informations complètes et/ou temps réel, tels que les changements de la demande, l’embouteillage soudain causé par un accident, etc. Le partage et la mise à jour d'information logistique peut améliorer l'efficacité d’IRP. De plus, en raison de la spécificité de l'IRP dans la logistique urbaine, il est important de considérer d'autres critères comme les critères sociaux, environnementaux et le niveau de service qui pourraient être en conflictuel. L’objectif principal de cette thèse est de développer des modèles et des méthodes des IRP avec la prise en compte des incertitudes, du niveau de service et de l’impact environnemental, social en finalement les informations du temps réel (IRP dynamique). Dans cette thèse, trois modèles mathématiques sont proposés. Le premier modèle multi-objectif est pour identifier un compromis entre le niveau de service, les critères environnementaux et économiques. Pour gérer des paramètres incertains, on applique une approche floue. Dans le deuxième modèle, nous avons étudié l'impact des critères sociaux sur les IRPs en proposant un modèle mathématique bi-objectif. Une approche stochastique basée sur des scénarios est développée pour faire face à l'incertitude dans le modèle. Enfin, le troisième model concerne l'impact de l'utilisation d'informations du temps réel dans les IRP. Il est à noter que, selon la durée de vie du produit tant sur le plan financier que sur le plan écologique, les produits périssables sont considérés dans les trois modèles proposés. Les résultats montrent une gestion dynamique est beaucoup plus efficace que la statique. / The inventory management and transportation are two main activities of supply chain management. The joint optimization of these two activities is known as Inventory Routing Problem (IRP). The main objective of IRP is to determine the set of retailers to be delivered to in each period, the delivery sequence for each vehicle, and the quantities of goods delivered to each retailer for each period of a planning horizon. The traditional IRPs are faced different problems, caused mainly by lack of complete and/or timely information such as shifts in demand, traffic caused by a sudden vehicles accident, etc. sharing of updated and reliable logistics information can meaningful improve the efficiency of IRP. Moreover, because of the specificity of IRP in urban logistic, it is important to tack into account other criteria as social, environmental criteria and service level that could be in conflict. The main objective of this thesis is to (i) choose appropriate social, environmental and service level criteria, (ii) integrate them in mathematical models, and (iii) study the impact of these criteria on dynamic optimization of IRPs for perishable products under uncertain parameters. For this purpose, three mathematical models are proposed. The first model is multi-objective mathematical model in order to make a trade-off between service level, environmental criteria and economic. To decrease quantity of expired products, a nonlinear step function as holding cost function is integrated in the model. Moreover, to solve the problem a fuzzy possibilistic approach is applied to handle uncertain parameters. In the second model, a bi-objective mathematical model is proposed to study impact of social issues on the IRPs. In the proposed model, first objective function concerns economic criteria while the second one social issues. A scenario-based stochastic approach is developed to cope with uncertainty in the model. Finally, the third model concerns impact of using real-time information in efficiency of IRPs. It is noteworthy that, according significant role of perishable products in the both financially and ecology sides of IRPs, perishable products are considered in all three proposed model while even proposed models are appropriate to nonperishable ones as well. The results show that a dynamic management is more efficient than the static one.

In this thesis we report several of delivery problems. Here it is mostly describe Vehicle Routing Problem and Split Delivery Problem as suitable methods for the case study of the company Baťa a.s.In this thesis we used one of the most sofisticated software Roadnet Transportation Suite as effective program for distribution and planning routes.Finally we construct analysis as a support to find the optimal solution for the final strategical decision of the company Baťa a.s.