Continuous cooling system in conjunction with laser surgery for ear reshaping

1064nm Nd:YAG laser promotes chondrocytes regeneration and cartilage reshaping by upregulating local estrogen levels

Cartilage is frequently used as a scaffolds for repairing and reconstructing body surface organs. However, after successful plastic surgery, transplanted cartilage scaffolds often exhibit deformation and absorption over time. To enhance the shaping stability of cartilage scaffolds and improve patients' satisfaction after reconstructions, we employed the ear folding models in New Zealand rabbits to confirm whether the 1064nm neodymium-doped yttrium aluminum garnet (Nd:YAG) laser could promote cartilage reshaping. There was an increase in collagen and aromatase (Cyp19) expression within the ear cartilage after laser treatment. Moreover, we have found that the Cyp19 inhibitor can inhibit the laser's effect on cartilage shaping and reduce collagen and Cyp19 expression. The overall findings suggest that treatment with 1064nm Nd:YAG laser irradiation can enhance estrogen levels in local cartilage tissues by upregulating Cyp19 expression in chondrocytes through photobiomodulation, thereby promoting the proliferation and collagen secretion of chondrocytes to improve cartilage reshaping and stability.

Repopulation of decellularised articular cartilage by laser-based matrix engraving

BACKGROUND

In spite of advances in the treatment of cartilage defects using cell and scaffold-based therapeutic strategies, the long-term outcome is still not satisfying since clinical scores decline years after treatment. Scaffold materials currently used in clinical settings have shown limitations in providing suitable biomechanical properties and an authentic and protective environment for regenerative cells. To tackle this problem, we developed a scaffold material based on decellularised human articular cartilage.

METHODS

Human articular cartilage matrix was engraved using a CO₂ laser and treated for decellularisation and glycosaminoglycan removal. Characterisation of the resulting scaffold was performed via mechanical testing, DNA and GAG quantification and in vitro cultivation with adipose-derived stromal cells (ASC). Cell vitality, adhesion and chondrogenic differentiation were assessed. An ectopic, unloaded mouse model was used for the assessment of the in vivo performance of the scaffold in combination with ASC and human as well as bovine chondrocytes. The novel scaffold was compared to a commercial collagen type I/III scaffold.

FINDINGS

Crossed line engravings of the matrix allowed for a most regular and ubiquitous distribution of cells and chemical as well as enzymatic matrix treatment was performed to increase cell adhesion. The biomechanical characteristics of this novel scaffold that we term CartiScaff were found to be superior to those of commercially available materials. Neo-tissue was integrated excellently into the scaffold matrix and new collagen fibres were guided by the laser incisions towards a vertical alignment, a typical feature of native cartilage important for nutrition and biomechanics. In an ectopic, unloaded in vivo model, chondrocytes and mesenchymal stromal cells differentiated within the incisions despite the lack of growth factors and load, indicating a strong chondrogenic microenvironment within the scaffold incisions. Cells, most noticeably bone marrow-derived cells, were able to repopulate the empty chondrocyte lacunae inside the scaffold matrix.

INTERPRETATION

Due to the better load-bearing, its chondrogenic effect and the ability to guide matrix-deposition, CartiScaff is a promising biomaterial to accelerate rehabilitation and to improve long term clinical success of cartilage defect treatment.

FUNDING

Austrian Research Promotion Agency FFG ("CartiScaff" #842455), Lorenz Böhler Fonds (16/13), City of Vienna Competence Team Project Signaltissue (MA23, #18-08).

Repopulation of decellularised articular cartilage by laser-based matrix engraving

Background

In spite of advances in the treatment of cartilage defects using cell and scaffold-based therapeutic strategies, the long-term outcome is still not satisfying since clinical scores decline years after treatment. Scaffold materials currently used in clinical settings have shown limitations in providing suitable biomechanical properties and an authentic and protective environment for regenerative cells. To tackle this problem, we developed a scaffold material based on decellularised human articular cartilage.

Methods

Human articular cartilage matrix was engraved using a CO₂ laser and treated for decellularisation and glycosaminoglycan removal. Characterisation of the resulting scaffold was performed via mechanical testing, DNA and GAG quantification and in vitro cultivation with adipose-derived stromal cells (ASC). Cell vitality, adhesion and chondrogenic differentiation were assessed. An ectopic, unloaded mouse model was used for the assessment of the in vivo performance of the scaffold in combination with ASC and human as well as bovine chondrocytes. The novel scaffold was compared to a commercial collagen type I/III scaffold.

Findings

Crossed line engravings of the matrix allowed for a most regular and ubiquitous distribution of cells and chemical as well as enzymatic matrix treatment was performed to increase cell adhesion. The biomechanical characteristics of this novel scaffold that we term CartiScaff were found to be superior to those of commercially available materials. Neo-tissue was integrated excellently into the scaffold matrix and new collagen fibres were guided by the laser incisions towards a vertical alignment, a typical feature of native cartilage important for nutrition and biomechanics. In an ectopic, unloaded in vivo model, chondrocytes and mesenchymal stromal cells differentiated within the incisions despite the lack of growth factors and load, indicating a strong chondrogenic microenvironment within the scaffold incisions. Cells, most noticeably bone marrow-derived cells, were able to repopulate the empty chondrocyte lacunae inside the scaffold matrix.

Interpretation

Due to the better load-bearing, its chondrogenic effect and the ability to guide matrix-deposition, CartiScaff is a promising biomaterial to accelerate rehabilitation and to improve long term clinical success of cartilage defect treatment.

Funding

Austrian Research Promotion Agency FFG (“CartiScaff” #842455), Lorenz Böhler Fonds (16/13), City of Vienna Competence Team Project Signaltissue (MA23, #18-08)