Theses and Dissertations (Restricted)These theses are restricted, and cannot be viewed by anyone until they come out of embargo.http://hdl.handle.net/10898/36962024-03-28T19:00:56Z2024-03-28T19:00:56ZSkin Delivery of Natural Compounds by Enhancement TechnologiesGao, Xinyihttp://hdl.handle.net/10898/51282021-07-29T16:24:29ZSkin Delivery of Natural Compounds by Enhancement Technologies
Gao, Xinyi
Transdermal delivery represents an attractive alternative to oral delivery of drugs because it can avoid first-pass elimination and gastrointestinal irritation. In addition, transdermal systems are non-invasive and allows self-administration and easy termination which improve patient compliance. As the largest organ of the body, skin plays a very important role in protecting the underlying tissues and internal organs from external stimuli. Stratum corneum is the topmost layer of skin and it forms the rate-limiting barrier to the penetration of most molecules through skin. Only a limited number of drugs, moderately lipophilic with the molecular weight less than 500 Da, are able to be delivered through skin passively, which raises the need for using physical and chemical enhancement technologies to improve the permeation of the drug molecules through skin.
Natural products have been a big source of medicinal products for thousands of years with many useful drugs developed from plant sources to treat different diseases. However, the use and development of many promising natural compounds has been limited by poor oral bioavailability, and hence transdermal delivery can be explored as potential route to circumvent the problem.
The present studies mainly focused on using enhancement technologies to improve the skin delivery of natural compounds. For many natural compounds, passive permeation through skin is very low due to their low water solubility and stability. The present study provides a comprehensive investigation of in vitro skin delivery of honokiol, curcumin, and myrsinoside B with different delivery system and using physical or chemical enhancement technologies, such as microneedles or chemical enhancers. Our study also focused on the evaluation of the deactivation efficiency of an activated carbon based drug disposal system with model opioid drugs. Although opioid therapy is successful in relieving pain, it is associated with risks for misuse and abuse. Desorption studies were also done to test the system for potential leaching of the opioids from the disposal system in presence of water and alcohol.
Promising Immunotherapeutic Strategies for Cancer and Infectious Disease and Evaluation of Cell-Loaded Hydrogels for Type 1 DiabetesD'SA, SUCHETAhttp://hdl.handle.net/10898/51252021-07-29T16:26:16ZPromising Immunotherapeutic Strategies for Cancer and Infectious Disease and Evaluation of Cell-Loaded Hydrogels for Type 1 Diabetes
D'SA, SUCHETA
Advances in the area of vaccine immune responses has paved the way for new alternative delivery systems and novel painless routes of administration. Particulate delivery systems encapsulating protein antigens have been proved to improve the delivery and efficacy of vaccine responses. For the purpose of this dissertation, three separate projects with unique aims and hypotheses have been described. The first two projects focus on preparation and evaluation of a microparticulate vaccine incorporating antigens for an infectious disease [respiratory syncytial virus (RSV)] and cancer (melanoma), which have no licensed vaccines till date. In project 1, we have developed and tested a vaccine against RSV we have used a unique strategy of encapsulating virus-like particles prepared with the F protein, present on the surface of the respiratory syncytial virus. We used a biodegradable matrix composed of cellulose polymers for biocompatibility and better uptake by immune cells.
Adjuvants have long been administered with vaccines to improve the longevity and magnitude of an antigen-specific immune response. Hence, we carried out an in vitro screening assay using dendritic cells stimulated with RSV F-VLP vaccine with/without adjuvants such as alum, MF59, MPL, R848, poly (I:C) and flagellin. We observed significant enhancement of immune markers such as nitric oxide, CD80, CD86 and MHC II with several adjuvants. Another important aspect of vaccine delivery is the route of vaccination. The transdermal route of vaccination has gained popularity in research, owing to the rich source of immune cells in the dermis and epidermis. In our study, we vaccinated mice using hollow microneedles and the microparticulate formulation with a TLR-4 agonist, MPL A. We observed high CD4+ and CD8+ T cell populations and lower lung viral titers in the groups vaccinated with MPL and RSV F-VLP in microparticulate form, post-challenge with live RSV A2 virus.
Immunotherapeutic approaches to treat cancer have been successful owing to the selectivity and potency to target and eliminate tumors. Isolation of cancer antigens that generate specific immune responses and eliminate tumors has been challenging. Project 2 focuses on a mechanistic screening approach that utilizes tumor associated antigens from B16F10 metastatic melanoma cells. In our study, we have investigated the immunogenicity of the B16F10 antigens by performing an in vitro mechanistic study to evaluate the response of particulate antigens and adjuvants as a critical step in the development of an effective therapeutic vaccine. The development of a vaccine against cancer is a big challenge since tumor cells express self-proteins and hence are poorly immunogenic. Our strategy utilizes the spray drying technique to prepare vaccine microparticles using whole cell lysate. We systematically studied activation of the immune system in vitro with the formulated microparticles. With an aim to increase the potency of our vaccine candidate, several toll-like receptor (TLR) and non-TLR adjuvants were also studied. MHC I/II and co-stimulatory expression measured by flow cytometry was found to upregulated in dendritic cells stimulated with vaccine and adjuvant microparticles. In a real-life scenario, the patient’s own tumor cells will be used as the vaccine which will be administered to them in via the oral or transdermal routes, and an in vitro screening assay could help determine whether the appropriate antigen and adjuvant combination would be suitable for future use. In future, we hope that specific antigens will be identified so that a strong specific immune response can be generated.
Cell encapsulation technology raises great hopes in medicine and biotechnology. Transplantation of encapsulated pancreatic islets represents a promising approach to the final cure of type 1 diabetes mellitus. We have also discussed a proof-of-concept study to treat type-1 diabetes mellitus wherein live beta cells embedded in a thermosensitive hydrogel matrix were injected in diabetic mice to observe reduction in glucose over a prolonged period. We aimed to evaluate a novel live cell therapy for type 1 diabetes using poloxamer 407 solution which at optimum concentration is liquid at room temperature, and gels at physiological conditions. We tested a thermosensitive hydrogel such as poloxamer 407 containing beta TC-6 cells to be delivered in a mouse model which would ensure continuous release of insulin for a prolonged period. The cells were found to be viable in the hydrogel matrix (25% w/w) as demonstrated by the Live/Dead and MTS assay. A preliminary in vitro immunogenicity study of the gel formulation containing beta TC-6 cells was evaluated using dendritic cells, which proved the gel protects cells from immune attack. The cells in aqueous formulation was injected intraperitoneally, into diabetic mice following which the formulation formed a depot. Blood glucose levels were found to decrease over 2 days, after which another dose of cells was given to match baseline glucose levels. After 35 days, the mice were sacrificed and immune effector and memory cells were quantified to observe the effect of formulation in vivo. No significant changes in cell counts were seen among groups.
Facilitated Delivery of Pharma- and Cosmeceuticals into Skin and Drug DisposalBakshi, Poojahttp://hdl.handle.net/10898/51232021-07-29T16:27:45ZFacilitated Delivery of Pharma- and Cosmeceuticals into Skin and Drug Disposal
Bakshi, Pooja
Transdermal drug delivery (TDD) has several advantages over other delivery approaches, offering a non-invasive route that bypasses first pass metabolism and provides sustained plasma drug levels. The global impact of the TDD industry has increased tremendously in the last few years. For effective TDD delivery, or for a drug to exert its activity, it needs to be delivered across the stratum corneum (SC). However, SC, the outermost layer of the skin, forms a formidable barrier that limits the delivery of drugs through skin, especially large and hydrophilic molecules such as peptides and polysaccharides. For a drug to be delivered passively via the transdermal route it should, ideally, be moderately lipophilic and have a molecular weight of <500 Daltons. The type of vehicle and formulation characteristics play a key role in delivering the required concentrations of various drugs across this barrier. As a result, different strategies have been developed and explored to enhance drug delivery, into and through skin. In our studies, we investigated the delivery of different pharma- and cosmeceuticals into the skin by screening various excipients to formulate effective delivery systems for their enhanced delivery.
The first aim included performance of mechanistic studies using chemical penetration enhancers (CPE), commonly used for topical and transdermal drug delivery.
Studies such as histology, Fourier-transform infrared spectroscopy (FTIR), and microscopic evaluation provided a better insight about the mechanism and efficiency of CPEs. These studies are important tools to evaluate interactions between the drug, enhancer, and skin and are useful to determine if a specific CPE can be used for targeted drug delivery. Thus, understanding the mechanism of CPEs, can enable the selection of a suitable vehicle in order to achieve targeted delivery for topical and transdermal formulations.
The second aim included development of a topical formulation for the passive delivery of a large hydrophilic molecule, heparinoid, across human skin. Various topical formulations, incorporating both hydrophilic and lipophilic penetration enhancers were formulated and screened for enhanced delivery of heparinoid in the skin. In vitro permeation of the formulation (s) was/were performed and a cell culture model was used to evaluate its irritation potential. The optimized formulation was then compared to the commercially available marketed formulations (cream, gel, ointment) in terms of skin permeation.
Delivery of topicals can be enhanced further with the aid of delivery techniques, such as iontophoresis, ablative laser, and microdermabrasion. In our third aim, different enhancement strategies commonly used in the cosmetic or dermatological clinics, such as microdermabrasion, ablative laser, iontophoresis, and combination of laser and microdermabrasion, and laser and iontophoresis, were employed for improving the topical delivery of a cosmeceutical agent. Argireline, an anti-aging peptide, used as a Botox substitute was the molecule investigated in this study.
Lastly, a novel drug disposal system consisting of a pouch containing granular activated carbon packaged within a water-soluble film reservoir was evaluated for its efficiency to deactivate unused medications. This system is designed to be used for disposal of unwanted medications, which is a major problem leading to unintentional risks of exposure and added environmental waste. In our fourth and fifth aim, we investigated the deactivation efficiency of the system for the disposal of various psychoactive model drugs. We also tested the deactivation profile of drugs (ranging from Schedule II to Schedule IV category) from different dosage forms such as tablets and capsules. Prior to analyzing the amount of the drug deactivated, stable and sensitive high performance liquid chromatography (HPLC-UV) analytical methods for methylphenidate hydrochloride and loxapine succinate, two model psychoactive prescription medications, having a high abuse potential, were developed and validated. In addition to psychoactive drugs, deactivation efficacy for fentanyl transdermal patches was evaluated as part of the fifth aim of our study.
Our results demonstrated that the type of excipients (permeation enhancers or vehicle) incorporated in the formulation as well as the type of delivery strategy employed, can markedly affect the permeation of the actives into the skin. In addition, our data established the efficacy of the unique drug disposal system by demonstrating the deactivation profile of some highly-abused drugs.
A Novel Brace Design for Ulnar Collateral Ligament Injury Prevention and RehabilitationWilzman, Andrewhttp://hdl.handle.net/10898/51222021-01-07T17:01:25ZA Novel Brace Design for Ulnar Collateral Ligament Injury Prevention and Rehabilitation
Wilzman, Andrew
Ulnar Collateral Ligament (UCL) complete tears are only known to be remedied by Tommy John Surgery, a reconstructive surgery that utilizes the palmaris longus tendon weaved in and around drilled holes in the humerus and ulna to reinforce and recreate the UCL. First completed in the mid 70s, this surgery has become more and more common for younger players in the last two decades. This study searches for a way to hinder the climbing growth of this injury, which is known to be caused by overuse of the throwing arm. A brace was designed and built to provide stabilizing forces to the elbow joint, and was tested on five former baseball players using a commercial EMG device. Due to the stabilizing forces on the brace, if the elbow flexion is less or greater than 45°, the brace will add a moment force on the elbow in the direction of the 45° flexion angle. In the beginning phases of throwing, the biceps voltages of two subjects decreased with the application of the brace, while three subjects showed the opposite effect. It was concluded that the two subjects with decreased biceps loads were allowing the brace to maintain its preferred 45° flexion, while the other three subjects worked against it. The EMG measurements showed consistently that the application of the brace decreased the voltage potentials of the muscles crossing over the elbow joint during the deceleration phase of throw.