The Experimental Research Of Hair Follicle Restitution

backgroundHair follicle structure is a very meaningfully second organ in the hair follicle. Not only its losing will bring great sufferings to the patients,but also itself is periodic and self-renewal regularly.It can exist continuously in the human body.This character is unique for body.It is a perfect model for epiepithelial-mesenchymal interactions, organ-tissue reconstitution,chromatogenesis,wound healing and skin cancer.The research of hair follicle reconstitution not only will bring the great heraldings for the suffers who need the hair transplantation,but also will have a great influence on tissue engineering and the realm of cell restitutions。Dom Unger's animal experiments were started from 1822 up to now in the hair follicle transplantationso It lasts 2 centuries。In 1957,this technique becomes mature after putting forward the hair follicle-provided theories by American scholar Orentreich。Professor limmer of the United States put forward hair follicle unit transplanting concept in 1995。This begins to be used in the clinic。The appearance is very natural and beautiful after transplantations。The processes of hair transplantations include the preparations of transplantations,area anaesthetized,preparations of areas and imbedding。Because the hair follicle areas provide the area scope limited,large density and restrictions of the hair follicle unit's speciality,there is a large difficulty in the cutting of the hair follicles。Although it takes a half-century development,there is still a larger progress and development in making hair transplantation surgery。Donor site of the hair is limited in the hair transplantations。In the other ways,the loss ratio of hair follicle unit is high in the surgical process。This limits extensive applications in the hair transplantation。It becomes bottleneck in the modern hair transplantation surgery progress。The surgical operation time is also very long at the same time。To some extent,this affects the operational effectiveness.At the earliest stage,people succeed in utilizing hair follicle cells to restruct hair follicle。Rogers etc will get the islated hair follicle from new-born mouse。Dermal fibroblast and islated hair follicles which is cultivated or not cultivated transplant on the dorsal of nude mouse。We can discover the thick hairs on the dorsal of nude mouse after 2-3 weds。Weinberg etc furtherly do research to demanded cell components in the development of hair。They utilize fresh dermal cells liquid which can induce hair follicle growing to reconstruct hair follicles。Alone hair follicle buds and cultivated dermal cells together construct the skins,but this can't induce the hairs。Isolated mature hair follicle can create the skins but can't create the hairs。Isolated mature hair follicles can induce the hairs by themselves。In the experiments,they find that the mouse bristle DPC possess the ability of inducing the hairs after cultivating。Therefore we think that the mature hair follicles themselves possess the needed ingredients which restruct the hair follicles。Cultivated dermal cells can't induce the hair follicle bud to form the hairs because they are lack of DPC。Jahoda etc do some research to the inducement mechanism。They think that the formations of hair follicle due to the interactions of the dermis and epidermis in the embryonic period。After birth,the interaction of the dermal and epidermal cells can induce the formation of the hair follicles。They possess the similar mechanism。Purposes 1.Carry on the segregations,cultivations and passaging for hair follicle cells。At last,we can determine the hair follicle's breeds and confirm the possibility of inducing the hair follicles to create the hairs。2.Find out a kind of ideal bracket or method to achieve the reconstructions of hair follicle。Carrying out hair transplantation experiment for xenoma or heterogeneity。3.The final purpose is about hair follicle restitutions。At the same time we begin to experiment all kinds ofmethods。At last,we find out a experimental method which possesses high effectiveness and good results。It can be a solid foundation for curing baldness。Methods1.Manufacture of mouse hair follicle cell-tissue mixture。We shuck c57 neonate rats' skins and cut into trivials。They are digested with 2%collagenase in 37℃for 4-6 hours。After blowing,we add D- hank's liquid to centrifuge in 500 rs/min for 1min。Then we keep the supernatant。The rest are digested with trypsogen in 37℃for 20-30 min。We add D- Hank's liquid to blow and centrifuge in 500 rs/min for 1min again。At last,we put the supernatants together。We centrifuge them in 1000 r/min for 10min。We pour out the supernatant and keep the rest。And we centrifuge them tautologically for three times。At last,we add 0.5 ml D-Hank's liquid.2.Maufacture of human hair follicle cell-tissue mixture。We flush specimen and clear the hairs。We wipe the specimen twice with 75%alcohol。And we flush the specimen with the running water。And we get rid of specimen's verge。All the procedures must be carried out in the sterility of circumtance。(1) Putting the clean specimen on the simple operation-table and dissecting the fascia。(2) cutting the specimen into pieces(length 3-4 cm,width 0.3-0.5 cm)。Cutting the leash from the juncture of dermis-adipose layer。(3)putting the adipose-layer tissue into the 0.5%dispase,4℃overnight(about 8-10 hs);Then they are digested in 37℃for 30 minutes,flush the tissue twice with the D'Hanks liquid,extrude the residul hair shaft,abandoning。(4)cutting the adipose tissue into pieces,digesting them with 0.2% collagenase in 37℃for 4-6 hs,change the adipose tissue into the fluid。(5)adding D'Hanks liquid into the centrifuge tubes to centrifuge(2000 r/ min×5 mins),abandoning the supernatant。The precipitation is a mixture of DPC,hair,fibrous tissue and other cellular ingredients。(6)utilizing D'Hanks liquid to flush the precipitate。Getting away from lots of DPC and other cellular ingredients in the net。Abandoning the hairs and fibrous tissue。(7)Putting human hair follicle cells mixture into centrifuge tube to centrifuge,1000 rs/min,the 5 mins,3-4 times。Abandoning the supernatant。The purpose is to get rid of the rest collagenase。3.Dermal papilla cells of rate vibrissa hair follicles were isolated by whole-follicle-digesting method,and cultured in DMED medium containing 15%FCS, the bioligical behavior in vitro was observed。4.Mouse or human hair follicle tissue mixture+collagen gel transplantations。Putting the tissue mixture and collagen gel together。Then we put them into DMEM。Cultivating them in the incubator for 12 or 18 hours。Then transplanting them into the nude mouse。5.Follicular cells were implanted onto the back skin of nude mouse by hypodermal injection,the histologic examination of the skin was performed after the 14days,30days or 60 days respectively。Results1.Adopting the new methods to transplant o This shorts the time of experimental manipulation and cut down the difficulty。At last,we get hair-like structures。2.Adopting human hair follicle cell-tissue mixture to transplant。And we get hair-like structures。 3.Adopting mixtures to transplant。Its effectiveness is not good。And there is not envious hair follicle structures。4.Adopting the mixture of DPE and hair follicle cell-tissue mixture to transplant。We get hair-like structures again。From the results,this is the best method。Conclusions1.In the first experiment,hair follicle restitutions involve the interactions of EMI。And this research emphasize the potential of hair follicle's passaging and the importance of interactions between epidermis and dermis。It is the preliminary research for hair follicle reconstruction model.2.In the second experiment,bilateral interaction is affirmative in the appearance of hair follicle。The model has been constructed。From now on,we have not report about human hair follicle constitutions。Therefore this is a effective research for hair follicle restitutions。3.In the third experiment,we also discover hair follicle-like structures。This shows that the materials are in good effect。But its results are worse than the previous results。These need to be the continual explorations。4.In the last experiment,we discover that the DPs are more important than epdermal cells in the hair follicle restitutions。In the long time,pure DPCs or pure epdermal cells can't restruct the hairs。If we can improve the methods or experiment the other cells,we can get the good actions。...