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Updated: May 11, 2026
Distinctive Capillary Action by Micro-channels in Bone-like Templates can Enhance Recruitment of Cells for Restoration of Large Bony Defect
Published on: September 11, 2015
Affinity Modifications of Porous Microscaffolds Impact Bone Regeneration by Modulating the Delivery Kinetics of Small
Yike Gao1, Xiaojing Yuan1, Ruoheng Gu2
1Department of Pediatric Dentistry National Engineering Laboratory for Digital and Material Technology of Stomatology, and Beijing Key Laboratory of Digital Stomatology, Peking University School and Hospital of Stomatology, Beijing 100081, China.
Abstract:
Biomaterials functionalized with small extracellular vesicles (sEVs) hold great regenerative potential, and their therapeutic efficacy hinges on the delivery kinetics of the sEVs. Achieving rapid and stable loading, along with precisely controlled release of sEVs, necessitates affinity modifications of biomaterials. Here, we provide a quantitative description of the interaction between sEVs and various affinity molecules (i.e., polydopamine (PDA), tannic acid (TA), heparin, polyethylenimine (PEI), and calcium phosphate (CaP)) through molecular dynamics simulation. The interaction strengths followed the order of PDA < heparin < TA < CaP < PEI. To tailor the delivery kinetics of stem cells from human exfoliated deciduous teeth (SHED)-derived sEVs with concentration-dependent bioactivities, we employed two representative affinity molecules, namely PDA and CaP, to modify PLGA porous microscaffolds (PLGA MS), resulting in PDA-modified PLGA MS (PDA@MS) and biomineralized PDA-modified PLGA MS (B/PDA@MS). The B/PDA@MS exhibited the highest loading efficiency (>20 μg/mg microscaffolds) and optimized the release profile of sEVs over 21 days. Upon injection into a 5 mm defect in the rat cranial bone, sEV-loaded B/PDA@MS demonstrated the highest level of bone regeneration, with the new bone volume fraction (BV/TV) and bone mineral density (BMD) reaching 64.0% and 604.5 mg/cm3 within 8 weeks, respectively. This work not only presents a biomineralized microscaffold with sustained sEVs release and high osteogenic potential but also offers guidance on the further design and translation of sEV-functionalized biomaterials with broader applications.
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