Mighty Dons Of Science News

A glow­ing tooth re­gen­er­at­ed in an adult mouse mouth. (Im­age cour­te­sy  Ta­ka­shi Tsuji, PhD., To­kyo Uni­ver­si­ty of Sci­ence, Or­gan Tech­nolo­gies Inc.) The work could serve as a prel­ude to oth­er or­gan re­place­ments us­ing a si­m­i­lar tech­nique, they pro­posed.

Re­search­ers say they have en­gi­neered the growth of fully func­tion­al re­place­ment teeth in mice, with the growth oc­cur­ring in the tooth’s prop­er place.

Tech­nol­o­gy ex­ists to de­vel­op some tis­sues in the lab that can be trans­planted in­to an­i­mals. But Et­suko Ike­da of To­kyo-based Or­gan Tech­no­log­ies Inc. and To­kyo Un­ivers­ity of Sci­ence in Chi­ba, Ja­pan, and col­leagues ex­plored ways to grow an or­gan in place.

The re­search­ers de­vel­oped a bioen­gi­neered tooth germ, a seed-like tis­sue con­tain­ing the cells and ge­net­ic in­struc­tions nec­es­sary to form a tooth. They then trans­planted the germ in­to the jaw­bones of mice.

The germs reg­u­larly grew in­to re­place­ment teeth, the in­ves­ti­ga­tors said. Track­ing gene ac­ti­vity in the trans­planted germ with a flu­o­res­cent glow­ing pro­tein, the re­search­ers found that genes nor­mally ac­tivated in tooth de­vel­opment were al­so ac­tive dur­ing the en­gi­neered re­place­ment’s growth.

The en­gi­neered tooth’s hard­ness was com­pa­ra­ble to that of nat­u­ral teeth, and nerve fibers could grow through­out and re­spond to pain stimula­t­ion, they al­so found. The re­sults are re­ported in this week’s early on­line edi­tion of the re­search jour­nal Pro­ceed­ings of the Na­tio­n­al Aca­de­my of Sci­en­ces.

“We pro­pose this tech­nol­o­gy as a mod­el for fu­ture or­gan re­place­ment ther­a­pies,” the re­search­ers wrote.