3d printing of composite calcium phosphate and collagen scaffolds for bone regeneration

Article review by John Grieco

            This week’s post is a review of a primary research article I found relevant to our program and is a great example of making something that matters.  As many of you have figured out, the task of making something meaningful is not easy.  Also, you are the only judge of what is meaningful to you, no one can tell you that what you make this quarter isn’t meaningful or doesn’t matter.  With that said, I have come to the conclusion that for me, making something that has a positive impact on someone or something else i.e. the Environment, seems to be the most meaningful way of creation.  Not only does this week’s primary research article address how 3d printing can be applied in the medical field but also the possibilities of alternative filament.  I know many of you have expressed the want to make and use alternative filaments and I hope that this post will further inspire you.

The article in review examines the possible use of low temperature 3d printing of a custom filament made from calcium phosphate and collagen to produce synthetic bone graft alternatives.  The authors hoped that their efforts would improve the current techniques used for bone grafts and bone implants.  The technique of 3d printing used in this experiment is similar to what we are familiar with when using the makerbot in that individual layers create the object.  Their process differs with the type of printer and material used.

The printer used is a ZPrinter 450 and the material this printer requires is in the form of a very fine powder.  The ZPrinter 450 was modified to print a mixture of calcium phosphate and an acidic binding solution.  Calcium phosphate is a bioceramic used in reconstructive surgery due to its biocompatibility and similarities to real bone. After designing the specific bone replacement using 3d modeling software similar to what we are using this quarter, the part is processed and then coated in collagen.  Collagen is used to promote cell growth of the human cells cultured on the surface of the 3d printed object.  The authors also discovered that by adding collagen to the calcium phosphate and binding material before printing increased cell viability and strength of the final object.

The newly created artificial bones, in this case a femur, were used to replace broken femurs on a number of mice.  The mice then were monitored over a nine-week healing period and then euthanized so that their tissues could be harvested and then analyzed.  The results of this study found that the new technique used for generating bone scaffolds did not produce artificial bone that was sufficiently osteoinductive.  Meaning that the new 3d printed bone material did not react adequately with the actual bone of the subject’s body and was not able to completely heal.

I am interested in the future application of 3d printing in the medical field and studies like this are continually pushing the technology towards new ways of helping one another.  Attached is a video of the printer our author’s used in their experiment and how it differs from the printing we are familiar with.

Click here to view the embedded video.