#bioscaffolds

Fix Skin

Our skin is a deceptively complex material, delicate but strong, protective but permeable. An ideal artificial skin substitute for wound healing must support blood vessel growth, have antibacterial properties, and be sufficiently porous for air and moisture exchange. A new approach has developed a scaffold to grow such tissue-engineered material by incorporating a glass-ceramic onto electrospun nanofibres made of chitosan – a sugar from shellfish outer skeletons – and gelatin (pictured). The scaffold was also laced with silver, which provides antibacterial properties, and was found to be compatible with the body and blood, and promoted cell growth. Connective cells (pink) fully attached and spread over the scaffold, and researchers then treated wounds on mice. The scaffolds showed good vessel and protein growth, and even supported the regeneration of glands and hair follicles, which means this approach may help wounds repair without leaving a scar.

Written by Anthony Lewis

Image from work by Esmaeel Sharifi and colleagues

Cellular and Molecular Research Center, Basic Health Sciences Institute, Shahrekord University of Medical Science; Dept of Emergency Medicine, School of Medicine, Hamadan University of Medical Sciences; School of Chemistry, Damghan University, Iran

Image originally published with a Creative Commons Attribution 4.0 International (CC BY 4.0)

Published in Bioengineering & Translational Medicine, July 2022

Smart Cells

Swelling, tenderness and weakness of the joints are the painful symptoms of rheumatoid arthritis. The condition – caused by the body’s immune system attacking its own healthy cells – can flare up and calm down over time, but can never be cured. And, if flare-ups are severe, they can even lead to bone erosion and deformity. Because standard anti-inflammatory drugs can cause unpleasant side effects with long-term use, researchers are developing so-called SMART cells (Stem cells Modified for Autonomous Regenerative Therapy) – pictured. These engineered cells are seeded onto a woven scaffold and grafted into the body wherein they secrete anti-inflammatory compounds only when flare-ups occur – when they detect inflammatory cytokines – thus minimising the chance of side effects. So far, the cells have been shown to respond to cytokines, suppress inflammation, and reduce bone damage in mice with a form of rheumatoid arthritis, all of which pave the way for human studies.

Written by Ruth Williams

Image from work by Yun-Rak Choi and Kelsey H. Collins, and colleagues, Guilak lab Washington University

Department of Orthopaedic Surgery, Washington University in St. Louis, St. Louis, MO, USA

Image copyright held by the original authors

Research published in Science Advances, September 2021

Nervous Dancers

Transported to the site of a spinal injury, here artificial chemicals aim to heal damaged cells. But, like new arrivals at a school disco, the molecules fail to make an impact until they’re encouraged to move – jiving about on a scaffold of nanofibres, they match the rhythms of natural molecules that dance around receptors in the cells’ surface, triggering growth and repair. Fine-tuning these bioactive chemicals makes them more mobile and 'sociable' – in this stretch of mouse spine (highlighted in green and blue) their frolicking signals limit the growth of scar tissue and encourage new blood vessels to develop. Eventually, neuron cells grow new branches or axons (red). In the future, coaxing molecules to move to different biological rhythms may help to encourage repair, and, hopefully, keep human bodies moving.

Written by John Ankers

Image from the Stupp Laboratory, Northwestern University

Simpson Querrey Institute for BioNanotechnology, Northwestern University, Chicago, IL, USA

Image copyright held by the original authors

Research by Z. Álvarez and colleagues, Northwestern University, published in Science, November 2021

Foundation for Growth

Like a plant weaving up a trellis, these mouse neurons have grown along a man-made support. Scaffolds like this could help people recovering from spinal cord injuries, which sever links between brain and body, restricting sensation or movement with limited scope for natural healing. Providing a physical bridge that mimics the body’s complex natural structures to guide regrowth could help, like a cast holds broken bones together during healing. The researchers produced the pictured scaffold with a process that uses targeted lasers to harden portions of a material before allowing the rest to wash away. The resulting mesh supported growth of two types of mouse neurons, and one structure was designed to encourage cells to penetrate through (pictured, neurons coloured to reflect depth of penetration). Making this work at full scale and in the human body is some way off, but this progress provides a structure for future development.

Written by Anthony Lewis

Image from work by Lokesh Agrawal and colleagues

Molecular Neuroscience Unit, Okinawa Institute of Science and Technology Graduate University, Kunigami-gun, Okinawa, Japan

Image originally published with a Creative Commons Attribution 4.0 International (CC BY 4.0)

Research published Materials Science and Engineering: C, December 2021

Healing Clefts

One in 700 babies in the UK have a cleft lip and palate – a gap in the upper lip and roof of the mouth, the palate. Currently, surgery can't fully bridge the gap in the palate. Tissue engineering may provide a solution through implanting bioscaffolds – scaffolds made from donor tissue with the donor cells removed and replaced with host cells in a process called recellularisation. Researchers now create a bioscaffold using the connective tissue that covers the hard palate in pigs. After the pig cells were removed, some bioscaffolds were perforated to create microscopic pores. The scaffolds were then recellularised with human mesenchymal stem cells. Scanning electron microscopy (pictured) revealed that the cells spread, layered up and matured. Notably in micro-perforated scaffolds, more bone-related genes were switched on in the stem cells. This approach therefore looks promising for treating cleft lips and palates.

Written by Lux Fatimathas

Image from work by M. I. Rizzo, L. Tomao, F. Locatelli, L. Leone and M. Zama, and colleagues/a>

Bambino Gesù Children’s Hospital, IRCCS and Department of Neuroscience, Università Cattolica del Sacro Cuore, Rome, Italy

Image originally published with a Creative Commons Attribution 4.0 International (CC BY 4.0)

Published in Scientific Reports, July 2021

Build-a-Bone

A hard blow to the face or skull can cause damage to the bone, often difficult to repair due to the multiple cell types that contribute to the healing process and the usually irregular shape of the defect. This is where collagen scaffolds come in. Engineered to stimulate the formation of new connective tissue, the scaffolds are made from components found in bone such as calcium, phosphate ions and sugar compounds. To improve their collagen scaffold, researchers investigated how the use of different sugar compounds in their scaffold affected processes involved in bone regeneration. This included stem cell activity, the growth of immune cells and the growth of blood vessels. The latter is often overlooked when optimising scaffolds. Pictured is a coloured electron microscope image of the group’s scaffold, complete with thread-like collagen fibres.

Written by Katy Pallister

Image from work by Marley J.Dewey and Vasiliki Kolliopoulos, and colleagues

Dept. of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, USA

Image copyright held by the original authors

Published in Materialia, August 2021

Muscle Meadows

Tissue engineers are scientists who build muscles, connective tissues, or other parts of organs in the hopes of repairing and replacing those damaged by disease or injury. They generally grow their cells on some sort of scaffold to recreate the 3D forms and contours of the organ or tissue they’re trying to mimic. Scaffolds must be compatible with cell adherence, organisation, and growth – in the case of muscle, for example, they must allow cells to grow in long parallel fibres – and it’s a bonus if the material is cheap enough to scale-up tissue production. That’s why the muscle cells in this photo (nuclei stained blue) are growing on grass. Yes, you read that correctly. Decellularised grass, it turns out, has natural microscopic grooves ideal for growing and fusing muscle cells into naturalistic fibres. What’s more, grass is readily available, incredibly inexpensive, and perhaps best of all it’s green.

Written by Ruth Williams

Image from work by Scott J. Allan, Marianne J. Ellis and Paul A. De Bank

Department of Pharmacy & Pharmacology and Centre for Therapeutic Innovation, University of Bath, Bath, UK

Image originally published with a Creative Commons Attribution 4.0 International (CC BY 4.0)

Published in Journal of Biomedical Materials Research Part A, May 2021

Механизм, с помощью которого bioscaffolds влияет на клеточное поведение

Исследование, проведенное в Университете Питтсбурга и МакГоуэн Института регенеративной медицины определяют механизм , с помощью которого bioscaffolds, используемый в регенеративной медицине, влияет на клеточное поведение, вопрос, который остаётся без ответа, так как эта технология впервые была разработана несколько лет назад. Полученные результаты были недавно опубликованы в Science Advances .