Microspheres deliver stem cell exosomes to break through bottlenecks in tissue regeneration

Journal Source

Bioactive Materials (Journal of Biomaterials, IF:18.9, JCR Q1), published in 2026. The research team from Peking University Shenzhen Hospital systematically reviewed strategies for injectable microspheres delivering stem cells and their derivatives in tissue regeneration.

Key Article Highlights

Material design: Natural polymers (collagen, gelatin, chitosan, alginate, hyaluronic acid) provide cell recognition sites and biomimetic microenvironments; synthetic polymers (PLA, PLGA, PEG, PCL) feature controllable degradation and mechanical properties. Composite design can synergistically combine the advantages of both types.

Preparation techniques: Microfluidics for monodisperse microspheres (CV<5%, particle size 50–300 μm) serves as the gold standard for cell encapsulation; emulsion methods are scalable but produce heterogeneous particle sizes; electrospraying is mild with high encapsulation efficiency; 3D printing enables precise structural customization.

Core functions: Microspheres act as 3D scaffolds, immune protective barriers and sustained-release carriers. Modifications such as RGD peptides promote cell adhesion, and matrix stiffness regulates stem cell differentiation.

Tissue applications: Bone regeneration (BMP-2/MSC microspheres, sequential release of VEGF/exosomes), cartilage (MeHA microspheres encapsulating exosomes), nerve (conductive microspheres), skin (ROS-responsive microspheres), myocardium (mitochondria delivery), pulmonary fibrosis (pCD47 coating for immune evasion).

Frontier directions: Microsphere delivery of apoptotic bodies, ternary microsphere-organoid-exosome systems to achieve the transition from passive delivery to active microenvironment programming.

Research Breakthrough

A collaborative delivery framework of “microsphere-stem cell-exosome” was systematically proposed, integrating material design, fabrication processes and tissue-specific requirements to provide a roadmap for translation from laboratory to clinic in regenerative medicine.

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