A series of well-defined diblock copolymers of acrylic acid with partially fluorinated acrylate and methacrylate monomers were synthesized using ATRP as potential 19F MRI imaging agents. The diblock copolymers could undergo spontaneous self-assembly in mixed and aqueous solvents to form stable micelles with a diameter from approximately 20-45 nm, having a fluorine-rich core that provides a strong signal for MRI examinations. The observed MRI image intensities were related to the NMR longitudinal and transverse relaxation times, and were found to depend on polymer structure and method of micellization. Two distinct T2 relaxation times were measured; on comparison of expected MRI image intensities with those observed experimentally, it was found that methacrylate polymers show systematically lower signal intensity than acrylate polymers. This is related to the presence of a population of nuclear spins having very short T2 relaxation times that cannot be detected under high-resolution NMR and MRI conditions.

A series of copolymers of trimethylene carbonate (TMC) and L-lactide (LLA) were synthesized and evaluated as scaffolds for the production of artificial blood vessels. The polymers were end-functionalized with acrylate, cast into films, and cross-linked using UV light. The mechanical, degradation, and biocompatibility properties were evaluated. High TMC polymers showed mechanical properties comparable to human arteries (Young's moduli of 1.2-1.8 MPa and high elasticity with repeated cycling at 10% strain). Over 84 days degradation in PBS, the modulus and material strength decreased gradually. The polymers were nontoxic and showed good cell adhesion and proliferation over 7 days using human mesenchymal stem cells. When implanted into the rat peritoneal cavity, the polymers elicited formation of tissue capsules composed of myofibroblasts, resembling immature vascular smooth muscle cells. Thus, these polymers showed properties which were tunable and favorable for vascular tissue engineering, specifically, the growth of artificial blood vessels in vivo.

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In the present work, the electronic structures and properties of a series of 2-ureido-4[1H]-pyrimidinone(UPy)-based monomers and dimers in various environments (vacuum, chloroform, and water) are studied by density functional theoretical methods. Most dimers prefer to form a DDAA-AADD (D, H-bond donor; A, H-bond acceptor) array in both vacuum and solvents. Topological analysis proved that intramolecular and intermolecular hydrogen bonds coexist in the dimers. Frequency and NBO calculations show that all the hydrogen bonds exhibit an obvious red shift in their stretching vibrational frequencies. Larger substituents at position 6 of the pyrimidinone ring with stronger electron-donating ability favor the total binding energy and free energy of dimerization. Calculations on the solvent effect show that dimerization is discouraged by the stronger polarity of the solvent. Further computations show that Dimer-1 may be formed in chloroform, but water molecules may interact with the donor or acceptor sites and hence disrupt the hydrogen bonds of Dimer-1.