Surface Eroding, Semicrystalline Polyanhydrides via Thiol-Ene "Click" Photopolymerization

Surface eroding and semicrystalline polyanhydrides,, with tunable erosion times and drug delivery pharmacokinetics largely:dictated by erosion, are producod easily with thiol-ene "click" Polymerization. This, strategy yields both linear and cross:: linked;network polyanhydrides that are readily and fully,cured within minutes using photoinitiation, can contain up to 60% crystallinity, and have tensile moduli up to 2,5 MPa for the compositions studied. Since they readily undergo hydrolysis and exhibit the oft preferred surface erosion mechanism, they may be particularly useful in drug delivery applications. The polyanhydrides were degraded under pseudophysiological conditions and cylindrical samples (10 min diameter X 5 mm height) were completely degraded within similar to 10 days, With the mass time profile being linear for much Of this time after a similar to 24 h induction period. Drug release studies, using, lidocaine as a model, showed pharmacokinetics that displayed a muted burst release in the early stages of erosion, but then a delayed release profile that is closely correlated to the erosion kinetics. Furthermore, : cytotoxicity studies of the linear and cross linked semicrystalline polyanhydrides, and degradation products; against fibroblast cells indicate that the materials have good,cytocompatibility: Overall; cells treated with up to 2500 mg/L of the semicrystalline polyanhydrides and degradation products show >90% human dermal fibroblast adult,-(HDFa) cell viability indicative of good cytocompatibility.