Microfluidic based polymer microspheres for sustained drug delivery: Recent advances in research and application

Background Biodegradable polymer microspheres have emerged as versatile delivery platforms widely exploited in drug delivery, agricultural engineering, and chromatographic separation. Encapsulating bioactive cargos within these polymeric matrices markedly improves their therapeutic efficacy and functional performance. To achieve precise control over microsphere size, structure, and monodispersity, microfluidic technologies offer a revolutionary approach. By manipulating fluid dynamics at the micrometer scale, microfluidics enables fabrication of highly monodisperse microspheres with tailored and well-defined architectures. Objectives Conventional encapsulation methods face inherent limitations in size control and reproducibility. Microfluidic fabrication of polymer microspheres has emerged as a precise alternative. This review systematically summarizes the device geometries, process parameters, and advanced structural designs of microfluidic-fabricated microspheres alongside their therapeutic applications, establishing a solid foundation for future research and clinical translation. Methods This systematic literature search across major biomedical and materials science databases screened relevant studies using defined eligibility criteria. Studies focusing on microfluidic-fabricated polymer microspheres for sustained drug delivery, including various device geometries, process parameters, and advanced structural designs, were screened. Results Microfluidic platforms yield highly monodisperse polymer microspheres with exceptional structural uniformity. Advanced process controls, including in-droplet precipitation, sequential solidification, and self-assembly kinetic modulations, enhance loading capacities while minimizing initial burst release. Multicompartmental architectures introduce spatial barriers for prolonged, sequential, or pulsatile release profiles. Consequently, these microcarriers optimize therapeutic outcomes across diverse disease models by sustaining localized chemotherapeutic delivery for lung and liver cancers, maintaining normoglycemia through oral insulin delivery or cell transplantation, prolonging ocular residence for glaucoma treatments, and accelerating diabetic wound tissue regeneration.