An Overview on Recent Progress of Microsphere‐Hydrogel Combination Systems as Scaffolds for Tissue Engineering

Abstract Tissue engineering aiming to develop and manufacture bioactive tissue or organ substitutes has been extensively studied. As an ideal scaffold material, the microsphere‐hydrogel combination system (MHCS), which combines the excellent functionalities of hydrogels and the unique structural advantages of microspheres, has been widely used in the development of biological substitutes for tissue engineering. With adjustable mechanical properties, the MHCS can simulate extracellular matrix‐like microstructure and microenvironment conducive to cell growth. These properties endow the MHCS with unique advantages in tissue repair, leading to significant progress in the regeneration of bone, skin, blood vessels, nerves, and other tissues. In this paper, we reviewed the latest progress in MHCS construction based on natural polymers, synthetic polymers, inorganic materials, and their composites. We also classified the raw materials that were utilized for the construction of microspheres and hydrogels and discussed the properties and applications of MHCS. Finally, the challenges and perspectives of MHCS were emphasized and pointed out the direction of future development, such as conducted advanced processing technologies and multidisciplinary cooperation to solve the limitations of uneven microsphere distribution and mismatched degradation rates, thus providing a reference for the design and fabrication of MHCS in the field of tissue engineering.