Surface and bulk modifications to photocrosslinked polyanhydrides to control degradation behavior.
A unique class of surface-eroding polyanhydrides was developed and explored for use in medical applications requiring high-strength biomaterials (e.g., orthopedics). In particular, dimethacrylated anhydride monomers were synthesized that photopolymerize quickly to render densely crosslinked polymer networks that degrade from the surface only by hydrolysis of labile anhydride linkages. Previous research on these materials has shown that the rate of hydrolysis of the degradable linkages is dependent on the hydrophobicity of the network composition. This article demonstrates the versatility in controlling the degradation process and resulting cellular response in these materials through the incorporation of new chemistries and the formation of polymer-polymer composite structures. Specifically, the rate of mass loss was controlled by the addition of hydrophobic linear polymers [e.g., poly(methyl methacrylate)] or monovinyl monomers based on hydrophobic natural components (e.g., cholesterol, steric acid). In addition, a newly established photografting method was used to modify the network surface chemistry with cholesterol- and stearic acid-based polymer grafts to control the degradation front and cellular interactions at the polymer-tissue interface. Finally, a porogen leaching method was used to form porous polyanhydride constructs, which can be subsequently filled with osteoblasts photoencapsulated in a hydrogel, as potential synthetic allograft materials for tissue engineering bone.
Burkoth
A K
AK
Department of Chemical Engineering, University of Colorado, Boulder, Colorado 80309-0424, USA.
Burdick
J
J
Anseth
K S
KS
D000812:Anhydrides / Q000138:chemical synthesis* / Q000737:chemistry*; D001672:Biocompatible Materials / Q000138:chemical synthesis* / Q000737:chemistry*; D001673:Biodegradation, Environmental; D001696:Biomechanical Phenomena; D001698:Biomedical Engineering; D001842:Bone and Bones / Q000601:surgery; D003432:Cross-Linking Reagents; D006801:Humans; D066298:In Vitro Techniques; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D010777:Photochemistry; D011108:Polymers / Q000138:chemical synthesis* / Q000737:chemistry*; D013499:Surface Properties
D000812:Anhydrides; D001672:Biocompatible Materials; D003432:Cross-Linking Reagents; D011108:Polymers