Biomaterials

The Weck group is developing new methods for the rapid synthesis of biomaterials.  We are developing new polymeric scaffolds for bone tissue engineering by combining: (i) a strategy to synthesize tunable and highly functionalized block copolymers, (ii) crosslinking of a nano/mesoscale separated phase to enhance mechanical properties, (iii) processing to provide a reinforced porous scaffold, and (iv) incorporation of biomimetic ligands to support osteoblast adhesion and function.  The combination of living polymerization techniques and thermally induced phase separation allows us to address the issues of inadequate mechanical properties and the lack of control of scaffold architectures.  In particular, our strategy is based on poly(lactic acid)/poly(norbornene) (PLA/PNB) block copolymers that are synthesized through a combination of ring-opening polymerization of lactides with ROMP, followed by the foaming of the resulting block copolymers into highly porous scaffolds.  PLA is a biodegradable and biorenewable polymer that has been used extensively in a variety of biomedical applications.  The Weck group has reported the first synthetic approaches towards functionalized poly(lactic acid) including the attachment of PEG and peptide sequences onto PLA.

A second thrust area in biomaterials is the development of delivery vehicles forin vitroandin vivoimaging and delivery applications. The Weck group is developing a straight-forward methodology for the synthesis of multifunctionalized linear polymers and dendrimers based on an orthogonal functionalization strategy in close analogy to the noncovalent methodology. For example, polyamide-based dendrimers possessing both a aldehyde, azide and amine moieties on their periphery have been synthesized and functionalized quantitatively with small organic and biological molecules with complete specificity of each functional moiety for its complementary motif. This orthogonal functionalization strategy has the potential to synthesize multifunctional dendrimers for a variety of applications ranging from targeted biological delivery vehicles to optical materials.