Preconditioning process for dermal tissue decellularization using electroporation with sonication

Decellularization to produce bioscaffolds composed of the extracellular matrix(ECM)uses enzymatic,chemical and physical methods to remove antigens and cellular components from tissues.Effective decellularization methods depend on the characteristics of tissues,and in particular,tissues with dense,complex structure and abundant lipid content are difficult to completely decellularize.Our study enables future research on the development of methods and treatments for fabricating bioscaffolds via decellularization of complex and rigid skin tissues,which are not commonly considered for decellularization to date as their structural and functional characteristics could not be preserved after severe decellularization.In this study,decellularization of human dermal tissue was done by a combination of both chemical(0.05%trypsin-EDTA,2%SDS and 1%Triton X-100)and physical methods(electroporation and sonication).After decellularization,the content of DNA remaining in the tissue was quantitatively confirmed,and the structural change of the tissue and the retention and distribution of ECM components were evaluated through histological and histochemical analysis,respectively.Conditions of the chemical pretreatment that increase the efficiency of physical stimulation as well as decellularization,and conditions for electroporation and sonication without the use of detergents,unlike the methods performed in previous studies,were established to enable the complete decellularization of the skin tissue.The combinatorial decellularization treatment formed micropores in the lipid bilayers of the skin tissues while removing all cell and cellular residues without affecting the ECM properties.Therefore,this procedure can be widely used to fabricate bioscaffolds by decellularizing biological tissues with dense and complex structures.

An effective method to generate controllable levels of ROS for the enhancement of HUVEC proliferation using a chlorin e6-immobilized PET film as a photo-functional biomaterial

Reactive oxygen species(ROS)are byproducts of cellular metabolism;they play a significant role as secondary messengers in cell signaling.In cells,high concentrations of ROS induce apoptosis,senescence,and contact inhibition,while low concentrations of ROS result in angiogenesis,proliferation,and cytoskeleton remodeling.Thus,controlling ROS generation is an important factor in cell biology.We designed a chlorin e6(Ce6)-immobilized polyethylene terephthalate(PET)film(Ce6-PET)to produce extracellular ROS under red-light irradiation.The application of Ce6-PET films can regulate the generation of ROS by altering the intensity of light-emitting diode sources.We confirmed that the Ce6-PET film could effectively promote cell growth under irradiation at 500 μW/cm^(2) for 30 min in human umbilical vein endothelial cells.We also found that the Ce6-PET film is more efficient in generating ROS than a Ce6-incorporated polyurethane film under the same conditions.Ce6-PET fabrication shows promise for improving the localized delivery of extracellular ROS and regulating ROS formation through the optimization of irradiation intensity.