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Peptides have shown to have vasculature-homing properties with aminopeptidase N (CD13) which are also expressed on tumor vasculature. Two types of peptides, TAMS-1 U3012DA110-1CSPGAKVRCY{Lys(Biotin)} and Biotin{PEG4}-MEWSLEKGYTIK, were individually electrosprayed with a biodegradable polymer, polycaprolactone (PCL). The peptide solution was created by dissolving 2mg of the peptide into 50ml of DMSO. The PCL solution was created by dissolving PCL in a mixture of Acetic Acid (AA), Formic Acid (FA), and Trifluoroethanol (TFE) in a 9:9:1 ratio. The peptide was coaxially electrosprayed in two different trials (one trial for each peptide) with PCL, where PCL is the core and the peptide is the sheath. Electrospraying parameters included applying a voltage of 44kV, humidity between 35-44%, tip to collector distance at 160mm, core flow rate of 0.5 ml/hr, and a sheath flow rate of 0.7 ml/hr. Development of a transverse axial spinneret was created to add another layer to the nanocapsule for a total of three layers. Samples were created using Fluorescein Sodium Salt as the core, PCL as the 1st sheath, and Rhodamine-6G as the 2nd sheath. Electrospraying parameters included applying a voltage of 43kV, humidity between 35-44%, tip to collector distance at 185mm, core flow rate at 0.1ml/hr with a 27 gauge needle and 5mL Becton plastic syringe, sheath flow rate for the 1st sheath at 0.2ml/hr using the sheath of the coaxial spinneret, sheath flow rate for the 2nd sheath at 0.2ml/hr with a 27 gauge needle and a 5mL Becton plastic syringe mounted onto the transverse spinneret. Ultraviolet-visible (UV-VIS) spectrophotometry is used to detect peptides present in the solution before electrospraying and peptide presence in the nanoparticles after electrospraying. The UV-VIS detected the presence of the TAMS-1 peptide in the electrosprayed nanoparticle at a wavelength of 230nm-280nm. Scanning Electron Microscopy (SEM) was completed to see the morphology of the active tumor targeting biodegradable/biocompatible polymer and the nanocapsules manufactured with three layers. Images showed individual nanocapsules sized at 100nm or less. Conglomerates are found to be 1µm or smaller In vivo biodistribution tests were completed using the two sets of samples created from the two different peptides. TAMS-1 U3012DA110-1CSPGAKVRCY{Lys(Biotin)}, showed uptake to tumors when analyzing the in-vivo biodistribution tests. Nanocapsules electrosprayed with PCL and NGR Peptide, Biotin{PEG4}-MEWSLEKGYTIK did not show uptake to the tumors.

This thesis presents the use of diblock copolymers, poly(butadiene)-b-poly(ethylene oxide) (PBm PEOn) and poly(isoprene)-b-poly(ethylene oxide) (PImPEOn), as amphiphilic molecular building blocks for the formation of synthetic polymer bilayer membranes using the droplet interface bilayer (DIB) technique. The DIB technique makes use of the self-assembly of amphiphilic macromolecules along oil-water droplet interfaces that can then be physically connected for the construction of liquid supported macromolecular bilayers at the droplet interface. These bilayer membranes are capable of hosting both naturally occurring and synthetic protein channels. This technique has been used to form synthetic bilayer membranes using various combinations of macromolecules. Much success has been had with a variety of lipids as the primary surfactant in the formation of DIBs, but questions remain regarding the use of diblock copolymers as the building blocks of DIBs. A diblock copolymer is a combination of two separate polymer blocks, in this case a hydrophobic block (polybutadiene) and a hydrophilic block (polyethylene oxide). Block copolymers (BCPs) exhibit a high level of tunability, with previous studies showing the possibility of varying the types of polymers used in either block, the chain length of either block and effective bilayer thickness, and/or terminal functional groups of the blocks, effectively changing the BCP’s functionality. BCP structures have been shown to have a higher stability and greater longevity than lipid structures due to their higher molecular weight. BCPs could allow for a new dimension of customization at the interface with a greater potential for testing a variety of applications. Previous attempts at using BCPs in the formation of DIBs were successful in forming bilayers with applied voltage, but the interfaces proved to be too thick for the successful incorporation of protein channels. The goals of this study are to show that a BCP with a lower molecular weight, PB12PEO8 or PI17PEO17, can successfully form a DIB, and then to quantify the effects of BCP presence in DIBs. With BCP bilayer DIBs realized, a wealth of potential applications could arise, ranging from drug delivery and protein characterization to neural networks and biomimetic computation.

Bone regeneration or augmentation is often required prior to or concomitant with implant placement. With the limitations of many existing technologies, a biologically compatible synthetic bone grafting substitute that is osteogenic, bioerodible, and provides spacing-making functionality while acting as a drug delivery vehicle for bioactive molecules could provide an alternative to ‘gold standard’ techniques. In the first part of this work, calcium sulfate (CS) space-making synthetic bone grafts with uniformly embedded poly(β-amino ester) (PBAE) biodegradable hydrogel particles was developed to allow controlled release of bioactive agents. The embedded gel particles’ influence on the physical and chemical characteristics of CS was tested. Namely, the compressive strength and modulus, dissolution, and morphology, were studied. All CS samples dissolved via zero-order surface erosion consistent to one another. Compression testing concluded that the amount, but not size, of embedded gel particles significantly decreased (up to 75%) the overall mechanical strength of the composite. Release studies were conducted to explore this system’s ability to deliver a broad range of drug types and sizes. Lysozyme (model protein for larger growth factors like bone morphogenic protein [BMP]) was loaded into PBAE particles embedded in CS matrix. The release of simvastatin, a small molecule drug capable of up regulating BMP production, was also examined. The release of both lysozyme and simvastatin was governed by dissolution of CS. The second part of this work proposed a bilayered CS implant. The physical and chemical properties were characterized similarly to the CS composites above. Release kinetics of directly loaded simvastatin in either the shell, core, or both were investigated. A sequential release of simvastatin was witnessed giving foresight of the composite’s tunability. The sequential release of an antibacterial, metronidazole, loaded into poly(lactic-co-glycolic acid) (PLGA) particles embedded into the shell along with directly loaded simvastatin either in the shell, core, or both layers was also observed. Through controlled release of bioactive agents, as well as a tunable layered geometry, CS-based implants have the potential to be optimized in order to help streamline the steps required for the healing and regeneration of compromised bone tissue.