The Biological Characteristic Of Human Dermal Fibroblastson Polyporous Scaffolds With Different Hole Sizes Embedded In Fibrin Gel

Background：Scaffolds provide mechanicalsupport、growing space、chemical and biological stimuliand make cell grow along their structure in order to develop some organs which havespecial functions, so scaffold devise is very important. Our experiment goal is investigatecells’morphological characteristic on scaffolds with differenthole sizes in vivo and in vitroand influence of different hole sizes of scaffold on cells’growing into scaffold in vivo.1.Influence of the embedding of fibrin gel on human dermalfibroblasts’morphological activity on polyporous scaffold with differentsizesobjective To investigate the influence of in mimic vivo culture or in vitro culture onhuman dermal fibroblasts’biological activityon polyporous scaffold with different sizes.Methods Experiment group: First, model F and L were made to make nickel gridswere observed in front and lateral direction respectively, second, purified human dermalfibroblasts and polyporous nickel grids with different sizes were cocultured and thenembedded with fibrin gel to mimic in vivo culture in model F and L. Control group: thesegroup was almost same as experiment group but without fibrin gel. Phase contrastmicroscope was used to observe bebaviour of human dermalfibroblasts,Phalloidin wasused to dye human dermal fibroblast to observe cells’actin cytoskeleton by confocalmicroscope. Result In experimental group, the main growth methods of human dermalfibroblasts were stratify methods that some fibroblasts first attached onto the inner surfaceof the voids, then more cells joined in and aligned on top of the attached cells. At the sametime, some fibroblasts grew into fibrin gel from nickel grids. In control group, as the sizeof holes of nickel grids became smaller, the main growth methods of fibroblasts changedfrom stratify method to bridge method. The phenomenon that fibroblast growing out fromnickel grids was not found.Conclusionin vitro condition,as hole sizes of scaffold become smaller,cells’morphological characteristic change from stratify method to brige method. In vivocondition, cells grow along the structure of scaffold, their morphological characteristicsremain unchanged as hole sizes of scaffold become smaller.2.Influence of3-dimensional polyporous scaffolds with different holesizes embedded in fibrin gel on human dermal fibroblasts’growing intoscaffoldObjective To investigate the influence of3-dimensional polyporous scaffolds withdifferent hole sizes on human dermal fibroblasts’biological characteristic in mimic vivoculture byembedding scaffolds in fibrin clot.Methods Three-dimensional polyporous scaffolds with different hole sizesweremade with nickel grids and PDMS (polydimethylsiloxane). Purified human dermalfibroblsats were seeded around these scaffolds, which were embedded infibrin gel.Experiment group and control group were set up according hole sizes of nickel grids.Fibroblasts were stained with Phalloidin and DAPI (4’,6-diamidino-2-phenylindole) andobserved usingPhase contrast microscope and confocal microscope, the growth lengthsoffibroblast were record and made a cell growth curve, the numbers of fibroblasts whichthreading nickel grids were also recorded to be used to compare.ResultsMorphological observation: most of fibroblasts adhered on the grid usingtentacles directly, and then cell and cell’sactin cytoskeleton began to grow along the structure of scaffolds. When the density of fibroblasts was large enough, cell began tothread holes of scaffolds in large quantities. Just a few of fibroblasts threaded holes in thethree-dimensional scaffold directly. DAPI fluorescence staining showed normalmorphology and quality of nuclei, no obvious cellular apoptosis or necrosis in every group.The cell growth curve showed that the growth speeds of fibroblasts on scaffolds withdifferent hole sizes were nearly the same, the growth speeds in control group were quickerthan experiment groups, plateaus were found in the cell growth curve when fibroblasts metthe nickel in experiment group. The numbers of fibroblasts threading holes of scaffoldswith different holesizes didn’t have significant difference.(P>0.05)Conclusion In mimic vivo culture, cells prefer to sick on scaffold firstly rather thanthread holes of scaffold directly.When cells’density become enough, they began to threadholes of scaffold. Cells’ growth speeds in3-dimensional scaffold are related with cell’sgrowth speed on scaffold and rate of cell’s proliferation but not related with hole sizes ofscaffolds.