Biodegradable polymers: PLA, PGA, and PLGA
Synthetic polyesters whose degradation rate can be dialled in — the most predictable scaffold material available.
Polylactic acid (PLA), polyglycolic acid (PGA), and their copolymer PLGA are the most widely used synthetic scaffold polymers, with a long clinical history in resorbable sutures and fixation devices. They degrade by hydrolysis into lactic and glycolic acid, which the body metabolises.
Their advantage is control. Varying the lactide-to-glycolide ratio and molecular weight tunes degradation from weeks to years, so a scaffold's lifetime can be matched to the tissue it hosts — the central problem of Scaffold design principles. That same tunability makes PLGA a standard depot for controlled release of growth factors.
Two drawbacks recur. The polymers are hydrophobic and carry no biological signal, so cells attach poorly unless the surface is modified. And bulk degradation releases acid, which can lower local pH and provoke inflammation — a consideration for the immune response. Composites with calcium phosphates address both, buffering acidity while adding bioactivity.
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