Bone-building cells favour different orthopaedic implant designs, study finds

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This study appears in a special series entitled “Women in Materials Engineering”.

The study, led by Reader in Multifunctional Materials Fabrication Dr. Carmen Torres Sanchez, tested designs of currently used implants and compared them to 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 JournalIt even shows that the researchers were able to speed up bone healing by making design modifications.

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 engineering subjects, praising its practical importance.

Implant design and previous studies

Orthopedic implants are medical devices used to replace lost joints or sections 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 triple cyclic minimal 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.

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The implants fill the gap remaining after trauma or removal of the affected bone and topology designs Supports bone healing. The image highlights the topology of a trabecular-like structure.

Study methods

Dr. Torres-Sanchez and his team, in collaboration with industrial partners Alloyed Ltd and Core Specialists Services Ltd, tested the mechanical properties of TPMS and the trabecular-like structures by means of 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.

Various scaffolding designs used in the study (CAD image). Left to right: two TPMS-type structures, two trabecular-like structures, and a reticular structure (used as a control scaffold, usually used nowadays).

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-lasting implants, those that promote faster healing, without relapses such as looseness or infections, without second surgeries, are a no-brainer for the NHS, 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 on fine-tuning the 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” that the paper appeared in women in engineering subjects sThe series is special and hopes that “more girls and women will be drawn to work in design and manufacturing, a field that is usually outnumbered by men”.

To read the study titled “Comparison of Selective, Commercially Fused Lasers of Pure Titanium Based on Triple Periodic Minimal Surfaces and Trabecular Stent-Based Scaffolds for Tissue Engineering,” click in full. here.

To read the special issue of Women in Engineering, click here.

Notes to editors

Press release reference number: 04/22