Bone-building cells favor different orthopedic implant designs

New bone implants that promote faster healing and ultimately reduce stress on the NHS could be available in the future thanks to new research by engineering experts at Loughborough University that is revealing which structures promote better bone healing.

The study, led by Dr. Carmen Torres Sanchez, a reader in the manufacture of multifunctional materials, tested the designs of currently used implants and compared them with new designs to better understand the structures favored by bone-building cells.

Dr. Torres Sanchez and her team of researchers have found that cells are sensitive to ‘topology’ – the way structures are arranged in a design – and this can be exploited to help tissues recover faster.

The new paper published in advanced engineering materials The journal, even shows that the researchers were able to speed up bone healing by making modifications to the design.

Dr. Torres Sanchez hopes that the results of the study “will see clinical application in the very near future to help patients with trauma and bone cancer.”

The paper was also included in a special series entitled “Women in Materials Engineering” praising its practical importance.

Implant design and previous studies

Orthopedic implants are medical devices used to replace lost joints or parts of bone, or to support damaged or diseased bones.

Bones in the body are made up of spaces and pores, which help give bones their biological and mechanical properties.

The implants look to mimic this porous structure in an effort to promote healing, faster integration of the implant into the body and replicate the mechanical properties of bone, including its ability to withstand forces from movement.

Two new types of designs were used in Dr. Torres Sanchez’s study: the triangular periodic simple surface (TPMS) and trabecular-like structures.

This study is one of the few worldwide that evaluates how design topology affects both biological and mechanical performance.

Study methods

Dr. Torres-Sanchez and his team, in collaboration with industrial partners Alloyed Ltd and Core Specialists Ltd, tested the mechanical properties of TPMS and the trabecular-like structures by 3D printing cubes – referred to as “scaffolding” – using a biocompatible material such as titanium.

The mechanical properties of the scaffolds were tested by applying forces that replicate the physiological loads that the implants would be exposed to in the body, to see if the new designs could withstand and at what point would they fail.

The biological performance of the designs was assessed by adding osteoblasts – precursor cells to osteoblasts (bone-building cells) – to the inside of the scaffolds to see if the cells could develop into the mineral substance, which forms bone.

the findings

The researchers found that cells prefer a random distribution of porosity, such as that seen in trabecular scaffolds, as they appear to ‘identify them as home’ when pore structure is not regulated.

The researchers were able to modify the design of the ‘house’ where the cells live to speed up the formation of the mineral matter.

On the significance of the study, Dr Torres Sanchez commented: “Successful long-term transplants, those that promote faster healing, without relapses such as flaccidity or inflammation, without second surgeries, need no NHS thinking, for the patient community.”

“Patients can return to their normal lives sooner, relieving the burden on hospitals, physical therapists and caregivers, and contributing to a healthier, happier and more active life.

“We engineers can contribute to this by providing designs and scaffolding that promote healing and help accelerate patient recovery, including mental health support.

“We continue to research fine-tuning designs, so that we can find later developments of these multifunctional scaffolds that are more attractive to cells.”

Dr. Torres-Sanchez added that it was “a privilege” to have the paper featured in a special series “Women in Engineering Materials” and she hopes “more girls and women will be drawn to work in design and manufacturing, a field that is usually outnumbered by men.”