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The composite blend of poly(L-lactide-co-D,L-lactide) (PLDLLA) with tricalcium phosphate (TCP) is used as PLDLLA/TCP scaffolds for bone engineering. [47] [48] Poly-L-lactic acid (PLLA) is the main ingredient in Sculptra, a facial volume enhancer used for treating lipoatrophy of the cheeks.
PLGA undergoes hydrolysis in the body to produce the original monomers: lactic acid and glycolic acid. These two monomers under normal physiological conditions, are by-products of various metabolic pathways in the body. Lactic acid is metabolized in the tricarboxylic acid cycle and eliminated via carbon dioxide and water.
When this monomer undergoes ring-opening polymerization, one equivalent of carbon dioxide gas is released for every lactic acid unit incorporated into the polymer: [1] This compound is prepared by treatment of lactic acid or its salts with phosgene or one of its equivalents, e.g. diphosgene. [1]
Nowadays, lactic acid is used as a monomer for producing polylactic acid (PLA) which later has application as biodegradable plastic. [9] This kind of plastic is a good option for substituting conventional plastic produced from petrochemicals because of low emission of carbon dioxide.
The degradation product, glycolic acid, is nontoxic, but like ethylene glycol, it is metabolized to oxalic acid, which could make it dangerous. A part of the glycolic acid is also excreted by urine. [9] Studies undergone using polyglycolide-made sutures have shown that the material loses half of its strength after two weeks and 100% after four ...
A wide variety of starting materials can be used to synthesize polyesters, and each monomer type endows the final polymer chain with different characteristics and properties. The ROP of cyclic dimeric glycolic or lactic acid forms α-hydroxy acids which then polymerize into poly-(α-esters). [10]
PCL was chosen over poly (lactic acid) (PLA) and poly (lactic-co-glycolic acid) (PLGA), because it is insoluble in HEMA but soluble in acetone. This is important because HEMA was used for the main conduit material and acetone was used to selectively dissolve the polymer fibers.
chemical synthesis from sugar derivatives (e.g., lactic acid) and lipids (such as vegetable fats and oils) from either plants or animals, fermentation of sugars or lipids, biotechnological production in microorganisms or genetically modified plants (e.g., polyhydroxyalkanoates (PHA). [3]