Development of a portable reflectance confocal microscope and its application in the noninvasive in vivo evaluation of mesenchymal stem cell-promoted cutaneous wound healing

The process of wound healing is routinely evaluated by histological evaluation in the clinic,which may cause scarring and secondary injury.Reflectance confocal microscopy(RCM)represents a noninvasive,real-time imaging technique that allows in vivo evaluation of the skin.Traditional RCM was wide-probe-based,which limited its application on uneven and covered skin.In this study,we report the development of a portable reflectance confocal microscope(PRCM)in which all components were assembled in a handheld shell.Although the size and weight of the PRCM were reduced based on the use of a microelectromechanical system,the resolution was kept at 0.91μm,and the field of view of the system was 343μm×532μm.When used in vivo,the PRCM was able to visualize cellular and nuclear morphology for both mouse and human skin.PRCM evaluations were then performed on wounds after topically applied mesenchymal stem cells(MSCs)or saline treatment.The PRCM allowed visualization of the formation of collagen bundles,re-epithelization from the wound edge to the wound bed,and hair follicle regeneration,which were consistent with histological evaluations.Therefore,we offer new insights into monitoring the effects of topically applied MSCs on the process of wound healing by using PRCM.This study illustrates that the newly developed PRCM represents a promising device for real-time,noninvasive monitoring of the dynamic process of wound healing,which demonstrates its potential to diagnose,monitor,or predict disease in clinical wound therapy.

A thermo-responsive rewritable plasmonic bio-memory by regulating single core-satellite gold nanocluster dissociation

A thermo-responsive rewritable plasmonic bio-memory chip has been successfully fabricated on an indium tin oxide(ITO)glass slide by assembling core-satellite gold nanoclusters with different size of gold nanoparticles(AuNPs)using double-strand DNA(dsDNA)linker.And the prepared 70@DNA20@13 gold nanoclusters(AuNCs)exhibited more stable and greater photothermal conversion ability.With short time irradiation by 633 nm microbeam laser,every individual AuNCs could be excited and remove the satellite AuNPs on its surface.Especially,in the dissociation process of AuNCs with 3−5 satellite,its color would change from yellow to green,which showed more significant reduction in the red channel of the dark-field microscopy(DFM)images and could be defined to state“0”and“1”respectively.Besides,this plasmonic nano bio-memory could transform cyclically its state between 0 and 1 which exhibited excellent rewritable ability.