fumarates and caprolactone

Aiming to achieve suitable polymeric biomaterials with controlled physical properties for hard and soft tissue replacements, we have developed a series of blends consisting of two photo-cross-linkable polymers: polypropylene fumarate (PPF) and polycaprolactone fumarate (PCLF). Physical properties of both un-cross-linked and UV cross-linked PPF/PCLF blends with PPF composition ranging from 0% to 100% have been investigated extensively. It has been found that the physical properties such as thermal, rheological, and mechanical properties could be modulated efficiently by varying the PPF composition in the blends. Thermal properties including glass transition temperature (T g) and melting temperature (T m) have been correlated with their rheological and mechanical properties. Surface characteristics such as surface morphology, hydrophilicity, and the capability of adsorbing serum protein from culture medium have also been examined for the cross-linked polymer and blend disks. For potential applications in bone and nerve tissue engineering, in vitro cell studies including cytotoxicity, cell adhesion, and proliferation on cross-linked disks with controlled physical properties have been performed using rat bone marrow stromal cells and SPL201 cells, respectively. In addition, the role of mechanical properties such as surface stiffness in modulating cell responses has been emphasized using this model blend system.

Topics: Animals; Biocompatible Materials; Bone Marrow; Caproates; Cell Adhesion; Cell Proliferation; Cells, Cultured; Fumarates; Lactones; Myelin Sheath; Polymers; Polypropylenes; Rats; Schwann Cells; Stem Cells; Stromal Cells; Ultraviolet Rays

Biodegradable polymer networks were prepared from fumaric acid derivatives of oligomeric esters. Photo-crosslinkable macromers were prepared by reacting star-shaped hydroxyl-group terminated lactide, epsilon-caprolactone and trimethylene carbonate based oligomers and fumaric acid monoethyl ester in the presence of N,N-dicyclohexylcarbodiimide and 4-dimethylamino pyridine at room temperature. The functionalization method is facile and suited for many hydroxyl-terminated oligomers. The reactivity of the fumarate end groups is such that, upon crosslinking by UV radical polymerization, networks with high gel contents (up to 96%) can be obtained without the addition of reactive diluents. The physical properties of the networks can be tuned by adjusting the composition, architecture and molecular weight of the oligomeric precursors. Such networks, built up of non-toxic compounds and designed to release benign degradation products, may find wide application in tissue engineering and other areas of biomedical research.

Topics: 4-Aminopyridine; Biocompatible Materials; Biodegradation, Environmental; Caproates; Cross-Linking Reagents; Dicyclohexylcarbodiimide; Dioxanes; Free Radicals; Fumarates; Glass; Lactones; Light; Macromolecular Substances; Magnetic Resonance Spectroscopy; Microscopy, Electron, Scanning; Models, Chemical; Polyesters; Polymers; Temperature; Tensile Strength; Tissue Engineering; Ultraviolet Rays