RGD peptide and graphene oxide co-functionalized PLGA nanofiber scaffolds for vascular tissue engineering

In recent years,much research has been suggested and examined for the development of tissue engineering scaffolds to promote cellular behaviors.In our study,RGD peptide and graphene oxide(GO)co-functionalized poly(lactide-co-glycolide,PLGA)(RGD-GO-PLGA)nanofiber mats were fabricated via electrospinning,and their physicochemical and thermal properties were characterized to explore their potential as biofunctional scaffolds for vascular tissue engineering.Scanning electron microscopy images revealed that the RGD-GO-PLGA nanofiber mats were readily fabricated and composed of randomoriented electrospun nanofibers with average diameter of 558nm.The successful co-functionalization of RGD peptide and GO into the PLGA nanofibers was confirmed by Fourier-transform infrared spectroscopic analysis.Moreover,the surface hydrophilicity of the nanofiber mats was markedly increased by co-functionalizing with RGD peptide and GO.It was found that the mats were thermally stable under the cell culture condition.Furthermore,the initial attachment and proliferation of primarily cultured vascular smoothmuscle cells(VSMCs)on the RGD-GO-PLGA nanofibermats were evaluated.It was revealed that the RGD-GO-PLGA nanofibermats can effectively promote the growth of VSMCs.In conclusion,our findings suggest that the RGD-GO-PLGA nanofiber mats can be promising candidates for tissue engineering scaffolds effective for the regeneration of vascular smooth muscle.

Sprayable nanomicelle hydrogels and inflammatory bowel disease patient cell chips for development of intestinal lesion-specific therapy

All-in-one treatments represent a paradigm shift in future medicine.For example,inflammatory bowel disease(IBD)is mainly diagnosed by endoscopy,which could be applied for not only on-site monitoring but also the intestinal lesion-targeted spray of injectable hydrogels.Furthermore,molecular conjugation to the hydrogels would program both lesion-specific adhesion and drug-free therapy.This study validated this concept of all-in-one treatment by first utilizing a well-known injectable hydrogel that underwent efficient solution-to-gel transition and nanomicelle formation as a translatable component.These properties enabled spraying of the hydrogel onto the intestinal walls during endoscopy.Next,peptide conjugation to the hydrogel guided endoscopic monitoring of IBD progress upon adhesive gelation with subsequent moisturization of inflammatory lesions,specifically by nanomicelles.The peptide was designed to mimic the major component that mediates intestinal interaction with Bacillus subtilis flagellin during IBD initiation.Hence,the peptide-guided efficient adhesion of the hydrogel nanomicelles onto Toll-like receptor 5(TLR5)as the main target of flagellin binding and Notch-1.The peptide binding potently suppressed inflammatory signaling without drug loading,where TLR5 and Notch-1 operated collaboratively through downstream actions of tumor necrosis factor-alpha.The results were produced using a human colorectal cell line,clinical IBD patient cells,gut-on-a-chip,a mouse IBD model,and pig experiments to validate the translational utility.