Human telomerase reverse transcriptase and glucose-regulated protein 78 increase the life span of articular chondrocytes and their repair potential

Delivering Nucleic-Acid Based Nanomedicines on Biomaterial Scaffolds for Orthopedic Tissue Repair: Challenges, Progress and Future Perspectives

As well as acting to fill defects and allow for cell infiltration and proliferation in regenerative medicine, biomaterial scaffolds can also act as carriers for therapeutics, further enhancing their efficacy. Drug and protein delivery on scaffolds have shown potential, however, supraphysiological quantities of therapeutic are often released at the defect site, causing off-target side effects and cytotoxicity. Gene therapy involves the introduction of foreign genes into a cell in order to exert an effect; either replacing a missing gene or modulating expression of a protein. State of the art gene therapy also encompasses manipulation of the transcriptome by harnessing RNA interference (RNAi) therapy. The delivery of nucleic acid nanomedicines on biomaterial scaffolds - gene-activated scaffolds -has shown potential for use in a variety of tissue engineering applications, but as of yet, have not reached clinical use. The current state of the art in terms of biomaterial scaffolds and delivery vector materials for gene therapy is reviewed, and the limitations of current procedures discussed. Future directions in the clinical translation of gene-activated scaffolds are also considered, with a particular focus on bone and cartilage tissue regeneration.

Exogenous hTERT gene transfected endothelial progenitor cells from bone marrow promoted angiogenesis in ischemic myocardium of rats

OBJECTIVE

To explore the biological behavior and the revascularizative ability of endothelial progenitor cells (EPCs) transfected with human telomerase reverse transcriptase (hTERT) gene.

METHODS

EPCs were isolated from mononuclear cells in bone marrow by using the method of density gradient centrifugation, then cultured with differential velocity adherent method, EPCs were transfected by recombinant plasmid carrying GFP report gene EGFP-hTERT. The EPCs secretion and proliferation ability were detected before and after transfection. The expression of EPCs mRNA were detected by RT-PCR before and after transfection. The new capillaries of infarct area were observed.

RESULTS

After transgenesis, the proliferation of EPCs were increased, and the secretion of NO, LDH, iNOS by EPCs were significantly increased compared to the non-transgenesis group. After transplanted the transfected EPCs into the ischemic myocardial of rats, revascularization were increased obviously.

CONCLUSION

EPCs maintained the original biological characteristics after transfecting exogenous hTER gene, the proliferation and survival rate were up-regulated significantly, and the revascularization ability of EPCs were significantly strengthen.