Biodegradable polylactic acid has attracted much attention due to the increasing environmental pollution from petroleum-based plastics. Polylactic acid (PLA) biopolymers can be produced from fermentative lactic acid (LA), which can be obtained via dark fermentation of renewable feedstocks. PLA polymers are a promising alternative that has the potential to replace petroleum-based products. Bio-based degradable polymers have numerous applications in the biomedical field and are used as disposable packaging materials. PLA, however, is a comparatively expensive material to produce, and its mechanical and physical properties are generally inferior to those of petroleum-based plastics. Significant scientific and technical efforts are therefore required to discover, develop, and use polymers that promote social and economic development. Polymerization reactions as well as rheological, mechanical, thermal, and barrier properties influence the performance of PLA polymers. High-end markets have prioritized the commercialization of PLA synthesis from fermentative LA and the improvement of its mechanical and thermal properties. Ring-opening polymerization can be used to synthesize PLA polymers with high molecular weight, which are helpful for both biomaterials and bioplastics applications due to their unique characteristics. This review is intended to contribute to a better understanding and further development of PLA for biomedical and bioplastic applications. It also highlights PLA's unique biological uses in tissue engineering, wound treatment, drug delivery, and orthopedics.