Building bones with bacteria

BuildingBonesWithBacteria
Combining bacterial cellulose with two common minerals offers an effective scaffolding material for repairing bones

Original source: Materials Today

Anyone with a broken bone could be forgiven for thinking of bacteria as foes, rather than friends, but in some cases they may have to reconsider. Prakit Sukyai at Kasetsart University in Thailand is working on using bacteria to help build new bone tissue and repair broken or defective bones.

The trick is to exploit what Sukyai calls the “outstanding features of bacterial cellulose” as a scaffolding material to promote bone repair. Sukyai and colleague Selorm Torgbo review the possibilities in the journal Applied Materials Today.

“There is an urgent need for new ways to regenerate bone tissue,” Sukyai points out, as existing options, such as bone grafts, can be complicated or have other limitations.

Cellulose is a natural biopolymer made from thousands of linked glucose molecules. It is best known as the key structural component of plant cell walls. It is largely responsible for the strength and rigidity of wood. But some bacteria also make cellulose in a pure form, free of other chemicals found mixed in with plant cellulose, making it an ideal scaffolding material for medical use.

Sukyai explains that bacterial cellulose is already extensively used in a variety of medical applications, including artificial blood vessels and skin, wound dressings and some specialized membranes. But it has not been widely employed in bone tissue engineering despite its excellent biocompatibility, biodegradability, useful chemical reactivities, and fibrous strength.

The basic idea is to patch up a bone break with a temporary non-toxic structure that will encourage bone-building cells to enter and get to work, while eventually harmlessly biodegrading. The scaffold must have a porous or gel-like structure that will also allow oxygen and nutrients to permeate through it to support cell growth, while also permitting biochemical waste to be cleared away by blood.

Sukyai and Torgbo explain how the cellulose can be made most effective by incorporating other chemicals that will support the regeneration process. The most promising of these are hydroxyapatite—a form of calcium phosphate naturally found in bone—and magnetite—a mineral not found in bone but which can encourage successful bone reformation.

“We believe this technique will start to enter the real world of healthcare applications within the next five to ten years,” says Sukyai.

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Torgbo, S & Sukyai, P.: “Bacterial cellulose-based scaffold materials for bone tissue engineering,” Applied Materials Today (2018)