Dual‐Controlled Release of Icariin/Mg²⁺ from Biodegradable Microspheres and Their Synergistic Upregulation Effect on Bone Regeneration

Abstract

Current scaffolds applied for bone tissue engineering are still lacking sufficient osteogenic capacity to induce efficient bone regeneration. Biodegradable microsphere‐type scaffolds are designed to achieve the dual‐controlled release of a Chinese medicine (i.e., icariin, ICA) and a bioactive ion (i.e., Mg2+), in order to achieve their synergistic effect on inducing osteogenesis. The hydrophobic icariin is preloaded onto MgO/MgCO3 (1:1 in weight ratio) particles at different amounts and then the particles are encapsulated into biodegradable poly(lactide‐co‐glycolide) (PLGA) microspheres (PMI) at a fixed fraction (20 wt%). Continuous releases of Mg2+ ion and icariin from the microspheres are detected, showing dependence on icariin amounts. At an optimized moderate loading amount, the resulting PMI‐M microspheres display the strongest activation effect on cell biological behaviors among all the designs. By implanting the PMI‐M microspheres into rat calvarial defects for 16 weeks, it is found that they can effectively enhance new bone formation, presenting significantly higher capacity in inducing osteogenesis than PMg (containing MgO/MgCO3 but without icariin) and blank PLGA microspheres. Clearly, the released Mg2+ ions are beneficial to osteogenesis, and the coincorporation of icariin exerts supplemental effects in inducing new bone formation, which suggest a promising strategy to regenerate severe bone injuries by designing a dual‐release system.

Antibacterial, conductive, and osteocompatible polyorganophosphazene microscaffolds for the repair of infectious calvarial defect

“…PATGP and PAGP microspheres, with an average diameter of 100 μm, were prepared using (W 1 /O)/W 2 double emulsion method, and details are provided in the Supporting Information. 27 Microspheres (1 g) were dispersed in Tris-buffered (10 mM, pH 8.5) aqueous solution containing 2 mg/ml dopamine hydrochloride, and the system was gently stirred for 16 hr at room temperature to complete the PDA coating. Then the microspheres, termed as PATGP@PDA and PAGP@PDA for simplification, were collected, rinsed with deionized water, and freeze-dried.…”

Multifunctional microcapsules: A theranostic agent for US/MR/PAT multi-modality imaging and synergistic chemo-photothermal osteosarcoma therapy

“…Therefore, a promising strategy on addressing undesirable difficulties is to apply theranostic nanomedicines with multi-modality imaging and synergistic chemo-photothermal osteosarcoma therapy, which simultaneously integrates the diagnostic and therapeutic agents into one single biological nanoplatform to significantly increase the accuracy of imaging diagnosis and boost the therapeutic effects. Here in this work, we proposed uniform PEGylated poly (lactic-co-glycolic acid) (PLGA) composite microcapsules of PB@(Fe 3 O 4 @PEG-PLGA) MCs with superparamagnetic Fe 3 O 4 NPs embedded in the shell and photothermal PB NPs encapsulated in the cavity via a premix membrane emulsification (PME) method [ [40] , [41] , [42] , [43] , [44] ]. PEG was selected as a hemocompatible and biocompatible chain to minimize toxicity to red blood cells and the body [ [45] , [46] , [47] ].…”

Construction of hollow polydopamine nanoparticle based drug sustainable release system and its application in bone regeneration

“… 20 , 21 Furthermore, nanomaterials in drug sustainable release systems should have low toxicity and high biocompatibility, and it is better to be metabolizable and biodegradable in vivo. 22 , 23 Currently, only few nanomaterials can meet all requirements. Therefore, there are limitations to construct an ideal drug sustainable release system.…”