IADR Abstract Archives
Multifunctional Carbon Dots for Enhanced miR218 Delivery and Accelerated Osteogenesis
Objectives: MicroRNAs (miRNAs) play a crucial role in regulating gene expression and have emerged as promising molecular targets in bone tissue engineering. However, the safe and effective delivery of miRNAs to target cells has remained a significant challenge, limiting their practical applications. In this work, a functional carbon dots named CPCDs-RGI was designed and synthesized as a non-viral gene vector for the efficient transfection of miR218 (an osteogenic miRNA regulator) to bone marrow-derived mesenchymal stem cells (BMSCs) for accelerated osteogenic differentiation.
Methods: The CPCDs-RGI was synthesized via conjugating a functional R9-G4-IKVAVW (RGI) peptide onto chitosan-polyethylenimine carbon dots (CPCDs). The CPCDs’ absorption bands were measured using UV-Vis. Size and zeta potential were measured by Malvern Zetasizer. The CPCDs-RGI strongly condensed miR-218 to prevent its RNase degradation. MTT was used to evaluate the cytotoxicity of CPCDs-RGI and CPCDs-RGI/miR218. PCR were used to evaluate the expressions of miR218 and osteogenic relative markers of the transfected cells at mRNA level, separately. In vitro mineralization was performed by ALP staining at day 7 and ARS staining at day 14. Then the CPCDs-RGI/miR218 were encapsulated into microspheres and implanted in a rat periodontal defect and harvested at four weeks after surgery to examine bone regeneration.
Results: CPCDs showed an intense absorption peak at 230 nm and a small broad peak at 320 nm. The emission was evaluated at different excitation wavelengths, showing to be wavelength dependent. When excited at 360 nm, the emission intensity of CPCDs showed concentration dependent. The average diameter of the CPCDs is around 4.2 nm. Owing to the positive charge of chitosan, PEI and cationic R9, CPCDs-RGI effectively condensed miR218 and formed positive charged complexes. The expression levels of osteogenic markers in the CPCDs-RGI4/miR218 group were significantly higher. More calcium deposition in CPCDs-RGI4/miR218 group were observed compared with other groups.
Conclusions: A multifunctional gene carrier, CPCDs-RGI, which conjugated functional RGI peptide on the carbon dots were synthesized and characterized in this work. The multifunctional CPCDs-RGI is an efficient miR218 delivery vector for accelerated osteogenesis.
Methods: The CPCDs-RGI was synthesized via conjugating a functional R9-G4-IKVAVW (RGI) peptide onto chitosan-polyethylenimine carbon dots (CPCDs). The CPCDs’ absorption bands were measured using UV-Vis. Size and zeta potential were measured by Malvern Zetasizer. The CPCDs-RGI strongly condensed miR-218 to prevent its RNase degradation. MTT was used to evaluate the cytotoxicity of CPCDs-RGI and CPCDs-RGI/miR218. PCR were used to evaluate the expressions of miR218 and osteogenic relative markers of the transfected cells at mRNA level, separately. In vitro mineralization was performed by ALP staining at day 7 and ARS staining at day 14. Then the CPCDs-RGI/miR218 were encapsulated into microspheres and implanted in a rat periodontal defect and harvested at four weeks after surgery to examine bone regeneration.
Results: CPCDs showed an intense absorption peak at 230 nm and a small broad peak at 320 nm. The emission was evaluated at different excitation wavelengths, showing to be wavelength dependent. When excited at 360 nm, the emission intensity of CPCDs showed concentration dependent. The average diameter of the CPCDs is around 4.2 nm. Owing to the positive charge of chitosan, PEI and cationic R9, CPCDs-RGI effectively condensed miR218 and formed positive charged complexes. The expression levels of osteogenic markers in the CPCDs-RGI4/miR218 group were significantly higher. More calcium deposition in CPCDs-RGI4/miR218 group were observed compared with other groups.
Conclusions: A multifunctional gene carrier, CPCDs-RGI, which conjugated functional RGI peptide on the carbon dots were synthesized and characterized in this work. The multifunctional CPCDs-RGI is an efficient miR218 delivery vector for accelerated osteogenesis.