Polyhydroxyalkanoates (PHAs) represent a promising class of biodegradable polyesters synthesized by various microorganisms as energy storage compounds. Their versatility and environmental friendliness make them potential candidates for replacing conventional plastics across numerous applications. However, challenges such as limited mechanical properties, high production costs, and thermal instability have hindered their widespread adoption. This paper explores innovative approaches to enhance the production, functionalization, and application of PHAs, particularly through the utilization of organic waste as a substrate, including chitosan, lignin, and cellulose derivatives. By incorporating various additives and blending with other biodegradable materials like chitosan, lignin, and cellulose derivatives, the functional properties of PHAs can be significantly improved. This study also delves into the impact of surface modifications on the thermal stability of PHAs, offering insights into their potential applications in fields such as biomedical implants, packaging, and sustainable materials. These advancements in PHA research not only address current material limitations but also contribute to a more sustainable and circular bioeconomy by valorizing organic waste streams into high-value biopolymers.