As a matter of fact researchers at various labs around the United States are working on this. Scientists from three separate places recently studied the use of resorbable polylactide polymers for a single level fusion.
A polymer is a natural or synthetic (man-made) material. Polymer means many parts. Millions of units are used in a regular pattern to make polymers. Plastic is a polymer. Starch made from sugar is a polymer. Polylactide (PLA) polymers used to form a bioabsorbable fusion implant are made from corn sugars.
They are biocompatible meaning the body accepts it as a natural substance and doesn't try to reject it. PLA polymers are also biodegradable. They break down easily and leave the body without problems.
These devices aren't ready yet. The work is being done on cadavers before testing it in animals and then humans.